diff options
Diffstat (limited to 'kernel')
186 files changed, 12287 insertions, 6262 deletions
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 3de8fd11873b..4198f0273ecd 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -251,7 +251,7 @@ config ARCH_USE_QUEUED_RWLOCKS config QUEUED_RWLOCKS def_bool y if ARCH_USE_QUEUED_RWLOCKS - depends on SMP + depends on SMP && !PREEMPT_RT config ARCH_HAS_MMIOWB bool diff --git a/kernel/acct.c b/kernel/acct.c index a64102be2bb0..3df53cf1dcd5 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -60,7 +60,6 @@ #include <linux/sched/cputime.h> #include <asm/div64.h> -#include <linux/blkdev.h> /* sector_div */ #include <linux/pid_namespace.h> #include <linux/fs_pin.h> @@ -478,7 +477,7 @@ static void do_acct_process(struct bsd_acct_struct *acct) /* * Accounting records are not subject to resource limits. */ - flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; + flim = rlimit(RLIMIT_FSIZE); current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; /* Perform file operations on behalf of whoever enabled accounting */ orig_cred = override_creds(file->f_cred); diff --git a/kernel/audit.h b/kernel/audit.h index b565ea16c0a5..d6a2c899a8db 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -6,6 +6,9 @@ * Copyright 2005 IBM Corporation */ +#ifndef _KERNEL_AUDIT_H_ +#define _KERNEL_AUDIT_H_ + #include <linux/fs.h> #include <linux/audit.h> #include <linux/skbuff.h> @@ -331,3 +334,5 @@ extern int audit_filter(int msgtype, unsigned int listtype); extern void audit_ctl_lock(void); extern void audit_ctl_unlock(void); + +#endif diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c index b2be4e978ba3..2cd7b5694422 100644 --- a/kernel/audit_tree.c +++ b/kernel/audit_tree.c @@ -593,7 +593,6 @@ static void prune_tree_chunks(struct audit_tree *victim, bool tagged) spin_lock(&hash_lock); } spin_unlock(&hash_lock); - put_tree(victim); } /* @@ -602,6 +601,7 @@ static void prune_tree_chunks(struct audit_tree *victim, bool tagged) static void prune_one(struct audit_tree *victim) { prune_tree_chunks(victim, false); + put_tree(victim); } /* trim the uncommitted chunks from tree */ diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 8dd73a64f921..b1cb1dbf7417 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -657,7 +657,7 @@ static int audit_filter_rules(struct task_struct *tsk, result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val); break; case AUDIT_SADDR_FAM: - if (ctx->sockaddr) + if (ctx && ctx->sockaddr) result = audit_comparator(ctx->sockaddr->ss_family, f->op, f->val); break; diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index bd04f4a44c01..a82d6de86522 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -29,7 +29,7 @@ config BPF_SYSCALL select IRQ_WORK select TASKS_TRACE_RCU select BINARY_PRINTF - select NET_SOCK_MSG if INET + select NET_SOCK_MSG if NET default n help Enable the bpf() system call that allows to manipulate BPF programs diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 3c4105603f9d..447def540544 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -287,6 +287,12 @@ static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key return 0; } +static void check_and_free_timer_in_array(struct bpf_array *arr, void *val) +{ + if (unlikely(map_value_has_timer(&arr->map))) + bpf_timer_cancel_and_free(val + arr->map.timer_off); +} + /* Called from syscall or from eBPF program */ static int array_map_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags) @@ -321,6 +327,7 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value, copy_map_value_locked(map, val, value, false); else copy_map_value(map, val, value); + check_and_free_timer_in_array(array, val); } return 0; } @@ -374,6 +381,19 @@ static void *array_map_vmalloc_addr(struct bpf_array *array) return (void *)round_down((unsigned long)array, PAGE_SIZE); } +static void array_map_free_timers(struct bpf_map *map) +{ + struct bpf_array *array = container_of(map, struct bpf_array, map); + int i; + + if (likely(!map_value_has_timer(map))) + return; + + for (i = 0; i < array->map.max_entries; i++) + bpf_timer_cancel_and_free(array->value + array->elem_size * i + + map->timer_off); +} + /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ static void array_map_free(struct bpf_map *map) { @@ -668,6 +688,7 @@ const struct bpf_map_ops array_map_ops = { .map_alloc = array_map_alloc, .map_free = array_map_free, .map_get_next_key = array_map_get_next_key, + .map_release_uref = array_map_free_timers, .map_lookup_elem = array_map_lookup_elem, .map_update_elem = array_map_update_elem, .map_delete_elem = array_map_delete_elem, @@ -1051,6 +1072,7 @@ static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr) INIT_WORK(&aux->work, prog_array_map_clear_deferred); INIT_LIST_HEAD(&aux->poke_progs); mutex_init(&aux->poke_mutex); + spin_lock_init(&aux->owner.lock); map = array_map_alloc(attr); if (IS_ERR(map)) { diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 2d4fbdbb194e..b2ee45064e06 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -360,6 +360,28 @@ bool bpf_iter_prog_supported(struct bpf_prog *prog) return supported; } +const struct bpf_func_proto * +bpf_iter_get_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + const struct bpf_iter_target_info *tinfo; + const struct bpf_func_proto *fn = NULL; + + mutex_lock(&targets_mutex); + list_for_each_entry(tinfo, &targets, list) { + if (tinfo->btf_id == prog->aux->attach_btf_id) { + const struct bpf_iter_reg *reg_info; + + reg_info = tinfo->reg_info; + if (reg_info->get_func_proto) + fn = reg_info->get_func_proto(func_id, prog); + break; + } + } + mutex_unlock(&targets_mutex); + + return fn; +} + static void bpf_iter_link_release(struct bpf_link *link) { struct bpf_iter_link *iter_link = @@ -664,7 +686,7 @@ int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx) rcu_read_lock(); migrate_disable(); - ret = BPF_PROG_RUN(prog, ctx); + ret = bpf_prog_run(prog, ctx); migrate_enable(); rcu_read_unlock(); diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index 70f6fd4fa305..9abcc33f02cf 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -28,6 +28,7 @@ struct bpf_struct_ops_value { struct bpf_struct_ops_map { struct bpf_map map; + struct rcu_head rcu; const struct bpf_struct_ops *st_ops; /* protect map_update */ struct mutex lock; @@ -367,6 +368,7 @@ static int bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, const struct btf_type *mtype, *ptype; struct bpf_prog *prog; u32 moff; + u32 flags; moff = btf_member_bit_offset(t, member) / 8; ptype = btf_type_resolve_ptr(btf_vmlinux, member->type, NULL); @@ -430,10 +432,12 @@ static int bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, tprogs[BPF_TRAMP_FENTRY].progs[0] = prog; tprogs[BPF_TRAMP_FENTRY].nr_progs = 1; + flags = st_ops->func_models[i].ret_size > 0 ? + BPF_TRAMP_F_RET_FENTRY_RET : 0; err = arch_prepare_bpf_trampoline(NULL, image, st_map->image + PAGE_SIZE, - &st_ops->func_models[i], 0, - tprogs, NULL); + &st_ops->func_models[i], + flags, tprogs, NULL); if (err < 0) goto reset_unlock; @@ -622,6 +626,14 @@ bool bpf_struct_ops_get(const void *kdata) return refcount_inc_not_zero(&kvalue->refcnt); } +static void bpf_struct_ops_put_rcu(struct rcu_head *head) +{ + struct bpf_struct_ops_map *st_map; + + st_map = container_of(head, struct bpf_struct_ops_map, rcu); + bpf_map_put(&st_map->map); +} + void bpf_struct_ops_put(const void *kdata) { struct bpf_struct_ops_value *kvalue; @@ -632,6 +644,17 @@ void bpf_struct_ops_put(const void *kdata) st_map = container_of(kvalue, struct bpf_struct_ops_map, kvalue); - bpf_map_put(&st_map->map); + /* The struct_ops's function may switch to another struct_ops. + * + * For example, bpf_tcp_cc_x->init() may switch to + * another tcp_cc_y by calling + * setsockopt(TCP_CONGESTION, "tcp_cc_y"). + * During the switch, bpf_struct_ops_put(tcp_cc_x) is called + * and its map->refcnt may reach 0 which then free its + * trampoline image while tcp_cc_x is still running. + * + * Thus, a rcu grace period is needed here. + */ + call_rcu(&st_map->rcu, bpf_struct_ops_put_rcu); } } diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c index 3ce75758d394..ebfa8bc90892 100644 --- a/kernel/bpf/bpf_task_storage.c +++ b/kernel/bpf/bpf_task_storage.c @@ -317,15 +317,13 @@ const struct bpf_map_ops task_storage_map_ops = { .map_owner_storage_ptr = task_storage_ptr, }; -BTF_ID_LIST_SINGLE(bpf_task_storage_btf_ids, struct, task_struct) - const struct bpf_func_proto bpf_task_storage_get_proto = { .func = bpf_task_storage_get, .gpl_only = false, .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, .arg1_type = ARG_CONST_MAP_PTR, .arg2_type = ARG_PTR_TO_BTF_ID, - .arg2_btf_id = &bpf_task_storage_btf_ids[0], + .arg2_btf_id = &btf_task_struct_ids[0], .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, .arg4_type = ARG_ANYTHING, }; @@ -336,5 +334,5 @@ const struct bpf_func_proto bpf_task_storage_delete_proto = { .ret_type = RET_INTEGER, .arg1_type = ARG_CONST_MAP_PTR, .arg2_type = ARG_PTR_TO_BTF_ID, - .arg2_btf_id = &bpf_task_storage_btf_ids[0], + .arg2_btf_id = &btf_task_struct_ids[0], }; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index cb4b72997d9b..dfe61df4f974 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3046,43 +3046,92 @@ static void btf_struct_log(struct btf_verifier_env *env, btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); } -/* find 'struct bpf_spin_lock' in map value. - * return >= 0 offset if found - * and < 0 in case of error - */ -int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) +static int btf_find_struct_field(const struct btf *btf, const struct btf_type *t, + const char *name, int sz, int align) { const struct btf_member *member; u32 i, off = -ENOENT; - if (!__btf_type_is_struct(t)) - return -EINVAL; - for_each_member(i, t, member) { const struct btf_type *member_type = btf_type_by_id(btf, member->type); if (!__btf_type_is_struct(member_type)) continue; - if (member_type->size != sizeof(struct bpf_spin_lock)) + if (member_type->size != sz) continue; - if (strcmp(__btf_name_by_offset(btf, member_type->name_off), - "bpf_spin_lock")) + if (strcmp(__btf_name_by_offset(btf, member_type->name_off), name)) continue; if (off != -ENOENT) - /* only one 'struct bpf_spin_lock' is allowed */ + /* only one such field is allowed */ return -E2BIG; off = btf_member_bit_offset(t, member); if (off % 8) /* valid C code cannot generate such BTF */ return -EINVAL; off /= 8; - if (off % __alignof__(struct bpf_spin_lock)) - /* valid struct bpf_spin_lock will be 4 byte aligned */ + if (off % align) + return -EINVAL; + } + return off; +} + +static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, + const char *name, int sz, int align) +{ + const struct btf_var_secinfo *vsi; + u32 i, off = -ENOENT; + + for_each_vsi(i, t, vsi) { + const struct btf_type *var = btf_type_by_id(btf, vsi->type); + const struct btf_type *var_type = btf_type_by_id(btf, var->type); + + if (!__btf_type_is_struct(var_type)) + continue; + if (var_type->size != sz) + continue; + if (vsi->size != sz) + continue; + if (strcmp(__btf_name_by_offset(btf, var_type->name_off), name)) + continue; + if (off != -ENOENT) + /* only one such field is allowed */ + return -E2BIG; + off = vsi->offset; + if (off % align) return -EINVAL; } return off; } +static int btf_find_field(const struct btf *btf, const struct btf_type *t, + const char *name, int sz, int align) +{ + + if (__btf_type_is_struct(t)) + return btf_find_struct_field(btf, t, name, sz, align); + else if (btf_type_is_datasec(t)) + return btf_find_datasec_var(btf, t, name, sz, align); + return -EINVAL; +} + +/* find 'struct bpf_spin_lock' in map value. + * return >= 0 offset if found + * and < 0 in case of error + */ +int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) +{ + return btf_find_field(btf, t, "bpf_spin_lock", + sizeof(struct bpf_spin_lock), + __alignof__(struct bpf_spin_lock)); +} + +int btf_find_timer(const struct btf *btf, const struct btf_type *t) +{ + return btf_find_field(btf, t, "bpf_timer", + sizeof(struct bpf_timer), + __alignof__(struct bpf_timer)); +} + static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct btf_show *show) @@ -4776,6 +4825,11 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; if (ctx_arg_info->offset == off) { + if (!ctx_arg_info->btf_id) { + bpf_log(log,"invalid btf_id for context argument offset %u\n", off); + return false; + } + info->reg_type = ctx_arg_info->reg_type; info->btf = btf_vmlinux; info->btf_id = ctx_arg_info->btf_id; @@ -6159,3 +6213,5 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { .arg3_type = ARG_ANYTHING, .arg4_type = ARG_ANYTHING, }; + +BTF_ID_LIST_GLOBAL_SINGLE(btf_task_struct_ids, struct, task_struct) diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index b567ca46555c..03145d45e3d5 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -19,7 +19,7 @@ #include "../cgroup/cgroup-internal.h" -DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_BPF_ATTACH_TYPE); +DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE); EXPORT_SYMBOL(cgroup_bpf_enabled_key); void cgroup_bpf_offline(struct cgroup *cgrp) @@ -113,12 +113,12 @@ static void cgroup_bpf_release(struct work_struct *work) struct list_head *storages = &cgrp->bpf.storages; struct bpf_cgroup_storage *storage, *stmp; - unsigned int type; + unsigned int atype; mutex_lock(&cgroup_mutex); - for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) { - struct list_head *progs = &cgrp->bpf.progs[type]; + for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) { + struct list_head *progs = &cgrp->bpf.progs[atype]; struct bpf_prog_list *pl, *pltmp; list_for_each_entry_safe(pl, pltmp, progs, node) { @@ -128,10 +128,10 @@ static void cgroup_bpf_release(struct work_struct *work) if (pl->link) bpf_cgroup_link_auto_detach(pl->link); kfree(pl); - static_branch_dec(&cgroup_bpf_enabled_key[type]); + static_branch_dec(&cgroup_bpf_enabled_key[atype]); } old_array = rcu_dereference_protected( - cgrp->bpf.effective[type], + cgrp->bpf.effective[atype], lockdep_is_held(&cgroup_mutex)); bpf_prog_array_free(old_array); } @@ -196,7 +196,7 @@ static u32 prog_list_length(struct list_head *head) * if parent has overridable or multi-prog, allow attaching */ static bool hierarchy_allows_attach(struct cgroup *cgrp, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup *p; @@ -204,12 +204,12 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp, if (!p) return true; do { - u32 flags = p->bpf.flags[type]; + u32 flags = p->bpf.flags[atype]; u32 cnt; if (flags & BPF_F_ALLOW_MULTI) return true; - cnt = prog_list_length(&p->bpf.progs[type]); + cnt = prog_list_length(&p->bpf.progs[atype]); WARN_ON_ONCE(cnt > 1); if (cnt == 1) return !!(flags & BPF_F_ALLOW_OVERRIDE); @@ -225,7 +225,7 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp, * to programs in this cgroup */ static int compute_effective_progs(struct cgroup *cgrp, - enum bpf_attach_type type, + enum cgroup_bpf_attach_type atype, struct bpf_prog_array **array) { struct bpf_prog_array_item *item; @@ -236,8 +236,8 @@ static int compute_effective_progs(struct cgroup *cgrp, /* count number of effective programs by walking parents */ do { - if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) - cnt += prog_list_length(&p->bpf.progs[type]); + if (cnt == 0 || (p->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) + cnt += prog_list_length(&p->bpf.progs[atype]); p = cgroup_parent(p); } while (p); @@ -249,10 +249,10 @@ static int compute_effective_progs(struct cgroup *cgrp, cnt = 0; p = cgrp; do { - if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) + if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) continue; - list_for_each_entry(pl, &p->bpf.progs[type], node) { + list_for_each_entry(pl, &p->bpf.progs[atype], node) { if (!prog_list_prog(pl)) continue; @@ -269,10 +269,10 @@ static int compute_effective_progs(struct cgroup *cgrp, } static void activate_effective_progs(struct cgroup *cgrp, - enum bpf_attach_type type, + enum cgroup_bpf_attach_type atype, struct bpf_prog_array *old_array) { - old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array, + old_array = rcu_replace_pointer(cgrp->bpf.effective[atype], old_array, lockdep_is_held(&cgroup_mutex)); /* free prog array after grace period, since __cgroup_bpf_run_*() * might be still walking the array @@ -328,7 +328,7 @@ cleanup: } static int update_effective_progs(struct cgroup *cgrp, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup_subsys_state *css; int err; @@ -340,7 +340,7 @@ static int update_effective_progs(struct cgroup *cgrp, if (percpu_ref_is_zero(&desc->bpf.refcnt)) continue; - err = compute_effective_progs(desc, type, &desc->bpf.inactive); + err = compute_effective_progs(desc, atype, &desc->bpf.inactive); if (err) goto cleanup; } @@ -357,7 +357,7 @@ static int update_effective_progs(struct cgroup *cgrp, continue; } - activate_effective_progs(desc, type, desc->bpf.inactive); + activate_effective_progs(desc, atype, desc->bpf.inactive); desc->bpf.inactive = NULL; } @@ -436,11 +436,12 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, enum bpf_attach_type type, u32 flags) { u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)); - struct list_head *progs = &cgrp->bpf.progs[type]; struct bpf_prog *old_prog = NULL; struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {}; struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {}; + enum cgroup_bpf_attach_type atype; struct bpf_prog_list *pl; + struct list_head *progs; int err; if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) || @@ -454,10 +455,16 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, /* replace_prog implies BPF_F_REPLACE, and vice versa */ return -EINVAL; - if (!hierarchy_allows_attach(cgrp, type)) + atype = to_cgroup_bpf_attach_type(type); + if (atype < 0) + return -EINVAL; + + progs = &cgrp->bpf.progs[atype]; + + if (!hierarchy_allows_attach(cgrp, atype)) return -EPERM; - if (!list_empty(progs) && cgrp->bpf.flags[type] != saved_flags) + if (!list_empty(progs) && cgrp->bpf.flags[atype] != saved_flags) /* Disallow attaching non-overridable on top * of existing overridable in this cgroup. * Disallow attaching multi-prog if overridable or none @@ -490,16 +497,16 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, pl->prog = prog; pl->link = link; bpf_cgroup_storages_assign(pl->storage, storage); - cgrp->bpf.flags[type] = saved_flags; + cgrp->bpf.flags[atype] = saved_flags; - err = update_effective_progs(cgrp, type); + err = update_effective_progs(cgrp, atype); if (err) goto cleanup; if (old_prog) bpf_prog_put(old_prog); else - static_branch_inc(&cgroup_bpf_enabled_key[type]); + static_branch_inc(&cgroup_bpf_enabled_key[atype]); bpf_cgroup_storages_link(new_storage, cgrp, type); return 0; @@ -520,7 +527,7 @@ cleanup: * all descendant cgroups. This function is guaranteed to succeed. */ static void replace_effective_prog(struct cgroup *cgrp, - enum bpf_attach_type type, + enum cgroup_bpf_attach_type atype, struct bpf_cgroup_link *link) { struct bpf_prog_array_item *item; @@ -539,10 +546,10 @@ static void replace_effective_prog(struct cgroup *cgrp, /* find position of link in effective progs array */ for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) { - if (pos && !(cg->bpf.flags[type] & BPF_F_ALLOW_MULTI)) + if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) continue; - head = &cg->bpf.progs[type]; + head = &cg->bpf.progs[atype]; list_for_each_entry(pl, head, node) { if (!prog_list_prog(pl)) continue; @@ -554,7 +561,7 @@ static void replace_effective_prog(struct cgroup *cgrp, found: BUG_ON(!cg); progs = rcu_dereference_protected( - desc->bpf.effective[type], + desc->bpf.effective[atype], lockdep_is_held(&cgroup_mutex)); item = &progs->items[pos]; WRITE_ONCE(item->prog, link->link.prog); @@ -574,11 +581,18 @@ static int __cgroup_bpf_replace(struct cgroup *cgrp, struct bpf_cgroup_link *link, struct bpf_prog *new_prog) { - struct list_head *progs = &cgrp->bpf.progs[link->type]; + enum cgroup_bpf_attach_type atype; struct bpf_prog *old_prog; struct bpf_prog_list *pl; + struct list_head *progs; bool found = false; + atype = to_cgroup_bpf_attach_type(link->type); + if (atype < 0) + return -EINVAL; + + progs = &cgrp->bpf.progs[atype]; + if (link->link.prog->type != new_prog->type) return -EINVAL; @@ -592,7 +606,7 @@ static int __cgroup_bpf_replace(struct cgroup *cgrp, return -ENOENT; old_prog = xchg(&link->link.prog, new_prog); - replace_effective_prog(cgrp, link->type, link); + replace_effective_prog(cgrp, atype, link); bpf_prog_put(old_prog); return 0; } @@ -667,12 +681,20 @@ static struct bpf_prog_list *find_detach_entry(struct list_head *progs, int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, struct bpf_cgroup_link *link, enum bpf_attach_type type) { - struct list_head *progs = &cgrp->bpf.progs[type]; - u32 flags = cgrp->bpf.flags[type]; - struct bpf_prog_list *pl; + enum cgroup_bpf_attach_type atype; struct bpf_prog *old_prog; + struct bpf_prog_list *pl; + struct list_head *progs; + u32 flags; int err; + atype = to_cgroup_bpf_attach_type(type); + if (atype < 0) + return -EINVAL; + + progs = &cgrp->bpf.progs[atype]; + flags = cgrp->bpf.flags[atype]; + if (prog && link) /* only one of prog or link can be specified */ return -EINVAL; @@ -686,7 +708,7 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, pl->prog = NULL; pl->link = NULL; - err = update_effective_progs(cgrp, type); + err = update_effective_progs(cgrp, atype); if (err) goto cleanup; @@ -695,10 +717,10 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, kfree(pl); if (list_empty(progs)) /* last program was detached, reset flags to zero */ - cgrp->bpf.flags[type] = 0; + cgrp->bpf.flags[atype] = 0; if (old_prog) bpf_prog_put(old_prog); - static_branch_dec(&cgroup_bpf_enabled_key[type]); + static_branch_dec(&cgroup_bpf_enabled_key[atype]); return 0; cleanup: @@ -714,13 +736,21 @@ int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, { __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); enum bpf_attach_type type = attr->query.attach_type; - struct list_head *progs = &cgrp->bpf.progs[type]; - u32 flags = cgrp->bpf.flags[type]; + enum cgroup_bpf_attach_type atype; struct bpf_prog_array *effective; + struct list_head *progs; struct bpf_prog *prog; int cnt, ret = 0, i; + u32 flags; - effective = rcu_dereference_protected(cgrp->bpf.effective[type], + atype = to_cgroup_bpf_attach_type(type); + if (atype < 0) + return -EINVAL; + + progs = &cgrp->bpf.progs[atype]; + flags = cgrp->bpf.flags[atype]; + + effective = rcu_dereference_protected(cgrp->bpf.effective[atype], lockdep_is_held(&cgroup_mutex)); if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) @@ -925,14 +955,14 @@ int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) link->cgroup = cgrp; link->type = attr->link_create.attach_type; - err = bpf_link_prime(&link->link, &link_primer); + err = bpf_link_prime(&link->link, &link_primer); if (err) { kfree(link); goto out_put_cgroup; } - err = cgroup_bpf_attach(cgrp, NULL, NULL, link, link->type, - BPF_F_ALLOW_MULTI); + err = cgroup_bpf_attach(cgrp, NULL, NULL, link, + link->type, BPF_F_ALLOW_MULTI); if (err) { bpf_link_cleanup(&link_primer); goto out_put_cgroup; @@ -986,7 +1016,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, */ int __cgroup_bpf_run_filter_skb(struct sock *sk, struct sk_buff *skb, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { unsigned int offset = skb->data - skb_network_header(skb); struct sock *save_sk; @@ -1008,12 +1038,12 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, /* compute pointers for the bpf prog */ bpf_compute_and_save_data_end(skb, &saved_data_end); - if (type == BPF_CGROUP_INET_EGRESS) { + if (atype == CGROUP_INET_EGRESS) { ret = BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY( - cgrp->bpf.effective[type], skb, __bpf_prog_run_save_cb); + cgrp->bpf.effective[atype], skb, __bpf_prog_run_save_cb); } else { - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb, - __bpf_prog_run_save_cb); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[atype], skb, + __bpf_prog_run_save_cb); ret = (ret == 1 ? 0 : -EPERM); } bpf_restore_data_end(skb, saved_data_end); @@ -1038,12 +1068,12 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb); * and if it returned != 1 during execution. In all other cases, 0 is returned. */ int __cgroup_bpf_run_filter_sk(struct sock *sk, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); int ret; - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[atype], sk, bpf_prog_run); return ret == 1 ? 0 : -EPERM; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); @@ -1065,7 +1095,7 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); */ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, struct sockaddr *uaddr, - enum bpf_attach_type type, + enum cgroup_bpf_attach_type atype, void *t_ctx, u32 *flags) { @@ -1090,8 +1120,8 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, } cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - ret = BPF_PROG_RUN_ARRAY_FLAGS(cgrp->bpf.effective[type], &ctx, - BPF_PROG_RUN, flags); + ret = BPF_PROG_RUN_ARRAY_CG_FLAGS(cgrp->bpf.effective[atype], &ctx, + bpf_prog_run, flags); return ret == 1 ? 0 : -EPERM; } @@ -1115,19 +1145,19 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr); */ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk, struct bpf_sock_ops_kern *sock_ops, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); int ret; - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops, - BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[atype], sock_ops, + bpf_prog_run); return ret == 1 ? 0 : -EPERM; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops); int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor, - short access, enum bpf_attach_type type) + short access, enum cgroup_bpf_attach_type atype) { struct cgroup *cgrp; struct bpf_cgroup_dev_ctx ctx = { @@ -1135,12 +1165,12 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor, .major = major, .minor = minor, }; - int allow = 1; + int allow; rcu_read_lock(); cgrp = task_dfl_cgroup(current); - allow = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, - BPF_PROG_RUN); + allow = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[atype], &ctx, + bpf_prog_run); rcu_read_unlock(); return !allow; @@ -1231,7 +1261,7 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = { int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, struct ctl_table *table, int write, char **buf, size_t *pcount, loff_t *ppos, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct bpf_sysctl_kern ctx = { .head = head, @@ -1271,7 +1301,7 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, rcu_read_lock(); cgrp = task_dfl_cgroup(current); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[atype], &ctx, bpf_prog_run); rcu_read_unlock(); kfree(ctx.cur_val); @@ -1289,7 +1319,7 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, #ifdef CONFIG_NET static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp, - enum bpf_attach_type attach_type) + enum cgroup_bpf_attach_type attach_type) { struct bpf_prog_array *prog_array; bool empty; @@ -1364,7 +1394,7 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, * attached to the hook so we don't waste time allocating * memory and locking the socket. */ - if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT)) + if (__cgroup_bpf_prog_array_is_empty(cgrp, CGROUP_SETSOCKOPT)) return 0; /* Allocate a bit more than the initial user buffer for @@ -1385,8 +1415,8 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, } lock_sock(sk); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[CGROUP_SETSOCKOPT], + &ctx, bpf_prog_run); release_sock(sk); if (!ret) { @@ -1460,7 +1490,7 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, * attached to the hook so we don't waste time allocating * memory and locking the socket. */ - if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT)) + if (__cgroup_bpf_prog_array_is_empty(cgrp, CGROUP_GETSOCKOPT)) return retval; ctx.optlen = max_optlen; @@ -1495,8 +1525,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, } lock_sock(sk); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[CGROUP_GETSOCKOPT], + &ctx, bpf_prog_run); release_sock(sk); if (!ret) { @@ -1556,8 +1586,8 @@ int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level, * be called if that data shouldn't be "exported". */ - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[CGROUP_GETSOCKOPT], + &ctx, bpf_prog_run); if (!ret) return -EPERM; @@ -1846,15 +1876,41 @@ const struct bpf_verifier_ops cg_sysctl_verifier_ops = { const struct bpf_prog_ops cg_sysctl_prog_ops = { }; +#ifdef CONFIG_NET +BPF_CALL_1(bpf_get_netns_cookie_sockopt, struct bpf_sockopt_kern *, ctx) +{ + const struct net *net = ctx ? sock_net(ctx->sk) : &init_net; + + return net->net_cookie; +} + +static const struct bpf_func_proto bpf_get_netns_cookie_sockopt_proto = { + .func = bpf_get_netns_cookie_sockopt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX_OR_NULL, +}; +#endif + static const struct bpf_func_proto * cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { #ifdef CONFIG_NET + case BPF_FUNC_get_netns_cookie: + return &bpf_get_netns_cookie_sockopt_proto; case BPF_FUNC_sk_storage_get: return &bpf_sk_storage_get_proto; case BPF_FUNC_sk_storage_delete: return &bpf_sk_storage_delete_proto; + case BPF_FUNC_setsockopt: + if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT) + return &bpf_sk_setsockopt_proto; + return NULL; + case BPF_FUNC_getsockopt: + if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT) + return &bpf_sk_getsockopt_proto; + return NULL; #endif #ifdef CONFIG_INET case BPF_FUNC_tcp_sock: diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 0a28a8095d3e..6e3ae90ad107 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -524,6 +524,7 @@ int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); int bpf_jit_harden __read_mostly; long bpf_jit_limit __read_mostly; +long bpf_jit_limit_max __read_mostly; static void bpf_prog_ksym_set_addr(struct bpf_prog *prog) @@ -817,7 +818,8 @@ u64 __weak bpf_jit_alloc_exec_limit(void) static int __init bpf_jit_charge_init(void) { /* Only used as heuristic here to derive limit. */ - bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, + bpf_jit_limit_max = bpf_jit_alloc_exec_limit(); + bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2, PAGE_SIZE), LONG_MAX); return 0; } @@ -827,7 +829,7 @@ int bpf_jit_charge_modmem(u32 pages) { if (atomic_long_add_return(pages, &bpf_jit_current) > (bpf_jit_limit >> PAGE_SHIFT)) { - if (!capable(CAP_SYS_ADMIN)) { + if (!bpf_capable()) { atomic_long_sub(pages, &bpf_jit_current); return -EPERM; } @@ -1821,20 +1823,26 @@ static unsigned int __bpf_prog_ret0_warn(const void *ctx, bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp) { + bool ret; + if (fp->kprobe_override) return false; - if (!array->aux->type) { + spin_lock(&array->aux->owner.lock); + + if (!array->aux->owner.type) { /* There's no owner yet where we could check for * compatibility. */ - array->aux->type = fp->type; - array->aux->jited = fp->jited; - return true; + array->aux->owner.type = fp->type; + array->aux->owner.jited = fp->jited; + ret = true; + } else { + ret = array->aux->owner.type == fp->type && + array->aux->owner.jited == fp->jited; } - - return array->aux->type == fp->type && - array->aux->jited == fp->jited; + spin_unlock(&array->aux->owner.lock); + return ret; } static int bpf_check_tail_call(const struct bpf_prog *fp) @@ -1879,7 +1887,7 @@ static void bpf_prog_select_func(struct bpf_prog *fp) * @err: pointer to error variable * * Try to JIT eBPF program, if JIT is not available, use interpreter. - * The BPF program will be executed via BPF_PROG_RUN() macro. + * The BPF program will be executed via bpf_prog_run() function. * * Return: the &fp argument along with &err set to 0 for success or * a negative errno code on failure @@ -2119,13 +2127,13 @@ int bpf_prog_array_update_at(struct bpf_prog_array *array, int index, int bpf_prog_array_copy(struct bpf_prog_array *old_array, struct bpf_prog *exclude_prog, struct bpf_prog *include_prog, + u64 bpf_cookie, struct bpf_prog_array **new_array) { int new_prog_cnt, carry_prog_cnt = 0; - struct bpf_prog_array_item *existing; + struct bpf_prog_array_item *existing, *new; struct bpf_prog_array *array; bool found_exclude = false; - int new_prog_idx = 0; /* Figure out how many existing progs we need to carry over to * the new array. @@ -2162,20 +2170,27 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array, array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); if (!array) return -ENOMEM; + new = array->items; /* Fill in the new prog array */ if (carry_prog_cnt) { existing = old_array->items; - for (; existing->prog; existing++) - if (existing->prog != exclude_prog && - existing->prog != &dummy_bpf_prog.prog) { - array->items[new_prog_idx++].prog = - existing->prog; - } + for (; existing->prog; existing++) { + if (existing->prog == exclude_prog || + existing->prog == &dummy_bpf_prog.prog) + continue; + + new->prog = existing->prog; + new->bpf_cookie = existing->bpf_cookie; + new++; + } } - if (include_prog) - array->items[new_prog_idx++].prog = include_prog; - array->items[new_prog_idx].prog = NULL; + if (include_prog) { + new->prog = include_prog; + new->bpf_cookie = bpf_cookie; + new++; + } + new->prog = NULL; *new_array = array; return 0; } diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 480e936c54d0..585b2b77ccc4 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -16,6 +16,7 @@ * netstack, and assigning dedicated CPUs for this stage. This * basically allows for 10G wirespeed pre-filtering via bpf. */ +#include <linux/bitops.h> #include <linux/bpf.h> #include <linux/filter.h> #include <linux/ptr_ring.h> @@ -168,6 +169,46 @@ static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) } } +static void cpu_map_bpf_prog_run_skb(struct bpf_cpu_map_entry *rcpu, + struct list_head *listp, + struct xdp_cpumap_stats *stats) +{ + struct sk_buff *skb, *tmp; + struct xdp_buff xdp; + u32 act; + int err; + + list_for_each_entry_safe(skb, tmp, listp, list) { + act = bpf_prog_run_generic_xdp(skb, &xdp, rcpu->prog); + switch (act) { + case XDP_PASS: + break; + case XDP_REDIRECT: + skb_list_del_init(skb); + err = xdp_do_generic_redirect(skb->dev, skb, &xdp, + rcpu->prog); + if (unlikely(err)) { + kfree_skb(skb); + stats->drop++; + } else { + stats->redirect++; + } + return; + default: + bpf_warn_invalid_xdp_action(act); + fallthrough; + case XDP_ABORTED: + trace_xdp_exception(skb->dev, rcpu->prog, act); + fallthrough; + case XDP_DROP: + skb_list_del_init(skb); + kfree_skb(skb); + stats->drop++; + return; + } + } +} + static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, void **frames, int n, struct xdp_cpumap_stats *stats) @@ -176,11 +217,6 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, struct xdp_buff xdp; int i, nframes = 0; - if (!rcpu->prog) - return n; - - rcu_read_lock_bh(); - xdp_set_return_frame_no_direct(); xdp.rxq = &rxq; @@ -227,17 +263,37 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, } } + xdp_clear_return_frame_no_direct(); + + return nframes; +} + +#define CPUMAP_BATCH 8 + +static int cpu_map_bpf_prog_run(struct bpf_cpu_map_entry *rcpu, void **frames, + int xdp_n, struct xdp_cpumap_stats *stats, + struct list_head *list) +{ + int nframes; + + if (!rcpu->prog) + return xdp_n; + + rcu_read_lock_bh(); + + nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, xdp_n, stats); + if (stats->redirect) - xdp_do_flush_map(); + xdp_do_flush(); - xdp_clear_return_frame_no_direct(); + if (unlikely(!list_empty(list))) + cpu_map_bpf_prog_run_skb(rcpu, list, stats); rcu_read_unlock_bh(); /* resched point, may call do_softirq() */ return nframes; } -#define CPUMAP_BATCH 8 static int cpu_map_kthread_run(void *data) { @@ -254,9 +310,9 @@ static int cpu_map_kthread_run(void *data) struct xdp_cpumap_stats stats = {}; /* zero stats */ unsigned int kmem_alloc_drops = 0, sched = 0; gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; + int i, n, m, nframes, xdp_n; void *frames[CPUMAP_BATCH]; void *skbs[CPUMAP_BATCH]; - int i, n, m, nframes; LIST_HEAD(list); /* Release CPU reschedule checks */ @@ -280,9 +336,20 @@ static int cpu_map_kthread_run(void *data) */ n = __ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH); - for (i = 0; i < n; i++) { + for (i = 0, xdp_n = 0; i < n; i++) { void *f = frames[i]; - struct page *page = virt_to_page(f); + struct page *page; + + if (unlikely(__ptr_test_bit(0, &f))) { + struct sk_buff *skb = f; + + __ptr_clear_bit(0, &skb); + list_add_tail(&skb->list, &list); + continue; + } + + frames[xdp_n++] = f; + page = virt_to_page(f); /* Bring struct page memory area to curr CPU. Read by * build_skb_around via page_is_pfmemalloc(), and when @@ -292,7 +359,7 @@ static int cpu_map_kthread_run(void *data) } /* Support running another XDP prog on this CPU */ - nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, n, &stats); + nframes = cpu_map_bpf_prog_run(rcpu, frames, xdp_n, &stats, &list); if (nframes) { m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, skbs); if (unlikely(m == 0)) { @@ -330,12 +397,6 @@ static int cpu_map_kthread_run(void *data) return 0; } -bool cpu_map_prog_allowed(struct bpf_map *map) -{ - return map->map_type == BPF_MAP_TYPE_CPUMAP && - map->value_size != offsetofend(struct bpf_cpumap_val, qsize); -} - static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd) { struct bpf_prog *prog; @@ -701,6 +762,25 @@ int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, return 0; } +int cpu_map_generic_redirect(struct bpf_cpu_map_entry *rcpu, + struct sk_buff *skb) +{ + int ret; + + __skb_pull(skb, skb->mac_len); + skb_set_redirected(skb, false); + __ptr_set_bit(0, &skb); + + ret = ptr_ring_produce(rcpu->queue, skb); + if (ret < 0) + goto trace; + + wake_up_process(rcpu->kthread); +trace: + trace_xdp_cpumap_enqueue(rcpu->map_id, !ret, !!ret, rcpu->cpu); + return ret; +} + void __cpu_map_flush(void) { struct list_head *flush_list = this_cpu_ptr(&cpu_map_flush_list); diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index fdc20892837c..f02d04540c0c 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -322,16 +322,6 @@ static int dev_map_hash_get_next_key(struct bpf_map *map, void *key, return -ENOENT; } -bool dev_map_can_have_prog(struct bpf_map *map) -{ - if ((map->map_type == BPF_MAP_TYPE_DEVMAP || - map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) && - map->value_size != offsetofend(struct bpf_devmap_val, ifindex)) - return true; - - return false; -} - static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog, struct xdp_frame **frames, int n, struct net_device *dev) @@ -499,6 +489,37 @@ static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, return 0; } +static u32 dev_map_bpf_prog_run_skb(struct sk_buff *skb, struct bpf_dtab_netdev *dst) +{ + struct xdp_txq_info txq = { .dev = dst->dev }; + struct xdp_buff xdp; + u32 act; + + if (!dst->xdp_prog) + return XDP_PASS; + + __skb_pull(skb, skb->mac_len); + xdp.txq = &txq; + + act = bpf_prog_run_generic_xdp(skb, &xdp, dst->xdp_prog); + switch (act) { + case XDP_PASS: + __skb_push(skb, skb->mac_len); + break; + default: + bpf_warn_invalid_xdp_action(act); + fallthrough; + case XDP_ABORTED: + trace_xdp_exception(dst->dev, dst->xdp_prog, act); + fallthrough; + case XDP_DROP: + kfree_skb(skb); + break; + } + + return act; +} + int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, struct net_device *dev_rx) { @@ -513,10 +534,9 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp, return __xdp_enqueue(dev, xdp, dev_rx, dst->xdp_prog); } -static bool is_valid_dst(struct bpf_dtab_netdev *obj, struct xdp_buff *xdp, - int exclude_ifindex) +static bool is_valid_dst(struct bpf_dtab_netdev *obj, struct xdp_buff *xdp) { - if (!obj || obj->dev->ifindex == exclude_ifindex || + if (!obj || !obj->dev->netdev_ops->ndo_xdp_xmit) return false; @@ -541,17 +561,48 @@ static int dev_map_enqueue_clone(struct bpf_dtab_netdev *obj, return 0; } +static inline bool is_ifindex_excluded(int *excluded, int num_excluded, int ifindex) +{ + while (num_excluded--) { + if (ifindex == excluded[num_excluded]) + return true; + } + return false; +} + +/* Get ifindex of each upper device. 'indexes' must be able to hold at + * least MAX_NEST_DEV elements. + * Returns the number of ifindexes added. + */ +static int get_upper_ifindexes(struct net_device *dev, int *indexes) +{ + struct net_device *upper; + struct list_head *iter; + int n = 0; + + netdev_for_each_upper_dev_rcu(dev, upper, iter) { + indexes[n++] = upper->ifindex; + } + return n; +} + int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx, struct bpf_map *map, bool exclude_ingress) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); - int exclude_ifindex = exclude_ingress ? dev_rx->ifindex : 0; struct bpf_dtab_netdev *dst, *last_dst = NULL; + int excluded_devices[1+MAX_NEST_DEV]; struct hlist_head *head; struct xdp_frame *xdpf; + int num_excluded = 0; unsigned int i; int err; + if (exclude_ingress) { + num_excluded = get_upper_ifindexes(dev_rx, excluded_devices); + excluded_devices[num_excluded++] = dev_rx->ifindex; + } + xdpf = xdp_convert_buff_to_frame(xdp); if (unlikely(!xdpf)) return -EOVERFLOW; @@ -560,7 +611,10 @@ int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx, for (i = 0; i < map->max_entries; i++) { dst = rcu_dereference_check(dtab->netdev_map[i], rcu_read_lock_bh_held()); - if (!is_valid_dst(dst, xdp, exclude_ifindex)) + if (!is_valid_dst(dst, xdp)) + continue; + + if (is_ifindex_excluded(excluded_devices, num_excluded, dst->dev->ifindex)) continue; /* we only need n-1 clones; last_dst enqueued below */ @@ -580,7 +634,11 @@ int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx, head = dev_map_index_hash(dtab, i); hlist_for_each_entry_rcu(dst, head, index_hlist, lockdep_is_held(&dtab->index_lock)) { - if (!is_valid_dst(dst, xdp, exclude_ifindex)) + if (!is_valid_dst(dst, xdp)) + continue; + + if (is_ifindex_excluded(excluded_devices, num_excluded, + dst->dev->ifindex)) continue; /* we only need n-1 clones; last_dst enqueued below */ @@ -615,6 +673,14 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, err = xdp_ok_fwd_dev(dst->dev, skb->len); if (unlikely(err)) return err; + + /* Redirect has already succeeded semantically at this point, so we just + * return 0 even if packet is dropped. Helper below takes care of + * freeing skb. + */ + if (dev_map_bpf_prog_run_skb(skb, dst) != XDP_PASS) + return 0; + skb->dev = dst->dev; generic_xdp_tx(skb, xdp_prog); @@ -646,18 +712,27 @@ int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, bool exclude_ingress) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); - int exclude_ifindex = exclude_ingress ? dev->ifindex : 0; struct bpf_dtab_netdev *dst, *last_dst = NULL; + int excluded_devices[1+MAX_NEST_DEV]; struct hlist_head *head; struct hlist_node *next; + int num_excluded = 0; unsigned int i; int err; + if (exclude_ingress) { + num_excluded = get_upper_ifindexes(dev, excluded_devices); + excluded_devices[num_excluded++] = dev->ifindex; + } + if (map->map_type == BPF_MAP_TYPE_DEVMAP) { for (i = 0; i < map->max_entries; i++) { dst = rcu_dereference_check(dtab->netdev_map[i], rcu_read_lock_bh_held()); - if (!dst || dst->dev->ifindex == exclude_ifindex) + if (!dst) + continue; + + if (is_ifindex_excluded(excluded_devices, num_excluded, dst->dev->ifindex)) continue; /* we only need n-1 clones; last_dst enqueued below */ @@ -671,12 +746,17 @@ int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, return err; last_dst = dst; + } } else { /* BPF_MAP_TYPE_DEVMAP_HASH */ for (i = 0; i < dtab->n_buckets; i++) { head = dev_map_index_hash(dtab, i); hlist_for_each_entry_safe(dst, next, head, index_hlist) { - if (!dst || dst->dev->ifindex == exclude_ifindex) + if (!dst) + continue; + + if (is_ifindex_excluded(excluded_devices, num_excluded, + dst->dev->ifindex)) continue; /* we only need n-1 clones; last_dst enqueued below */ diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c index ca3cd9aaa6ce..7b4afb7d96db 100644 --- a/kernel/bpf/disasm.c +++ b/kernel/bpf/disasm.c @@ -1,4 +1,4 @@ -// SPDX-License-Identifier: GPL-2.0-only +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * Copyright (c) 2016 Facebook */ diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h index e546b18d27da..a4b040793f44 100644 --- a/kernel/bpf/disasm.h +++ b/kernel/bpf/disasm.h @@ -1,4 +1,4 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * Copyright (c) 2016 Facebook */ diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 9c011f3a2687..32471ba02708 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -228,6 +228,32 @@ static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i) return (struct htab_elem *) (htab->elems + i * (u64)htab->elem_size); } +static bool htab_has_extra_elems(struct bpf_htab *htab) +{ + return !htab_is_percpu(htab) && !htab_is_lru(htab); +} + +static void htab_free_prealloced_timers(struct bpf_htab *htab) +{ + u32 num_entries = htab->map.max_entries; + int i; + + if (likely(!map_value_has_timer(&htab->map))) + return; + if (htab_has_extra_elems(htab)) + num_entries += num_possible_cpus(); + + for (i = 0; i < num_entries; i++) { + struct htab_elem *elem; + + elem = get_htab_elem(htab, i); + bpf_timer_cancel_and_free(elem->key + + round_up(htab->map.key_size, 8) + + htab->map.timer_off); + cond_resched(); + } +} + static void htab_free_elems(struct bpf_htab *htab) { int i; @@ -265,8 +291,12 @@ static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key, struct htab_elem *l; if (node) { + u32 key_size = htab->map.key_size; + l = container_of(node, struct htab_elem, lru_node); - memcpy(l->key, key, htab->map.key_size); + memcpy(l->key, key, key_size); + check_and_init_map_value(&htab->map, + l->key + round_up(key_size, 8)); return l; } @@ -278,7 +308,7 @@ static int prealloc_init(struct bpf_htab *htab) u32 num_entries = htab->map.max_entries; int err = -ENOMEM, i; - if (!htab_is_percpu(htab) && !htab_is_lru(htab)) + if (htab_has_extra_elems(htab)) num_entries += num_possible_cpus(); htab->elems = bpf_map_area_alloc((u64)htab->elem_size * num_entries, @@ -695,6 +725,14 @@ static int htab_lru_map_gen_lookup(struct bpf_map *map, return insn - insn_buf; } +static void check_and_free_timer(struct bpf_htab *htab, struct htab_elem *elem) +{ + if (unlikely(map_value_has_timer(&htab->map))) + bpf_timer_cancel_and_free(elem->key + + round_up(htab->map.key_size, 8) + + htab->map.timer_off); +} + /* It is called from the bpf_lru_list when the LRU needs to delete * older elements from the htab. */ @@ -719,6 +757,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) hlist_nulls_for_each_entry_rcu(l, n, head, hash_node) if (l == tgt_l) { hlist_nulls_del_rcu(&l->hash_node); + check_and_free_timer(htab, l); break; } @@ -790,6 +829,7 @@ static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) { if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) free_percpu(htab_elem_get_ptr(l, htab->map.key_size)); + check_and_free_timer(htab, l); kfree(l); } @@ -817,6 +857,7 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) htab_put_fd_value(htab, l); if (htab_is_prealloc(htab)) { + check_and_free_timer(htab, l); __pcpu_freelist_push(&htab->freelist, &l->fnode); } else { atomic_dec(&htab->count); @@ -920,8 +961,8 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, l_new = ERR_PTR(-ENOMEM); goto dec_count; } - check_and_init_map_lock(&htab->map, - l_new->key + round_up(key_size, 8)); + check_and_init_map_value(&htab->map, + l_new->key + round_up(key_size, 8)); } memcpy(l_new->key, key, key_size); @@ -1062,6 +1103,8 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, hlist_nulls_del_rcu(&l_old->hash_node); if (!htab_is_prealloc(htab)) free_htab_elem(htab, l_old); + else + check_and_free_timer(htab, l_old); } ret = 0; err: @@ -1069,6 +1112,12 @@ err: return ret; } +static void htab_lru_push_free(struct bpf_htab *htab, struct htab_elem *elem) +{ + check_and_free_timer(htab, elem); + bpf_lru_push_free(&htab->lru, &elem->lru_node); +} + static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags) { @@ -1102,7 +1151,8 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, l_new = prealloc_lru_pop(htab, key, hash); if (!l_new) return -ENOMEM; - memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size); + copy_map_value(&htab->map, + l_new->key + round_up(map->key_size, 8), value); ret = htab_lock_bucket(htab, b, hash, &flags); if (ret) @@ -1128,9 +1178,9 @@ err: htab_unlock_bucket(htab, b, hash, flags); if (ret) - bpf_lru_push_free(&htab->lru, &l_new->lru_node); + htab_lru_push_free(htab, l_new); else if (l_old) - bpf_lru_push_free(&htab->lru, &l_old->lru_node); + htab_lru_push_free(htab, l_old); return ret; } @@ -1339,7 +1389,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key) htab_unlock_bucket(htab, b, hash, flags); if (l) - bpf_lru_push_free(&htab->lru, &l->lru_node); + htab_lru_push_free(htab, l); return ret; } @@ -1359,6 +1409,35 @@ static void delete_all_elements(struct bpf_htab *htab) } } +static void htab_free_malloced_timers(struct bpf_htab *htab) +{ + int i; + + rcu_read_lock(); + for (i = 0; i < htab->n_buckets; i++) { + struct hlist_nulls_head *head = select_bucket(htab, i); + struct hlist_nulls_node *n; + struct htab_elem *l; + + hlist_nulls_for_each_entry(l, n, head, hash_node) + check_and_free_timer(htab, l); + cond_resched_rcu(); + } + rcu_read_unlock(); +} + +static void htab_map_free_timers(struct bpf_map *map) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + + if (likely(!map_value_has_timer(&htab->map))) + return; + if (!htab_is_prealloc(htab)) + htab_free_malloced_timers(htab); + else + htab_free_prealloced_timers(htab); +} + /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ static void htab_map_free(struct bpf_map *map) { @@ -1456,7 +1535,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, else copy_map_value(map, value, l->key + roundup_key_size); - check_and_init_map_lock(map, value); + check_and_init_map_value(map, value); } hlist_nulls_del_rcu(&l->hash_node); @@ -1467,7 +1546,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, htab_unlock_bucket(htab, b, hash, bflags); if (is_lru_map && l) - bpf_lru_push_free(&htab->lru, &l->lru_node); + htab_lru_push_free(htab, l); return ret; } @@ -1645,7 +1724,7 @@ again_nocopy: true); else copy_map_value(map, dst_val, value); - check_and_init_map_lock(map, dst_val); + check_and_init_map_value(map, dst_val); } if (do_delete) { hlist_nulls_del_rcu(&l->hash_node); @@ -1672,7 +1751,7 @@ again_nocopy: while (node_to_free) { l = node_to_free; node_to_free = node_to_free->batch_flink; - bpf_lru_push_free(&htab->lru, &l->lru_node); + htab_lru_push_free(htab, l); } next_batch: @@ -2034,6 +2113,7 @@ const struct bpf_map_ops htab_map_ops = { .map_alloc = htab_map_alloc, .map_free = htab_map_free, .map_get_next_key = htab_map_get_next_key, + .map_release_uref = htab_map_free_timers, .map_lookup_elem = htab_map_lookup_elem, .map_lookup_and_delete_elem = htab_map_lookup_and_delete_elem, .map_update_elem = htab_map_update_elem, @@ -2055,6 +2135,7 @@ const struct bpf_map_ops htab_lru_map_ops = { .map_alloc = htab_map_alloc, .map_free = htab_map_free, .map_get_next_key = htab_map_get_next_key, + .map_release_uref = htab_map_free_timers, .map_lookup_elem = htab_lru_map_lookup_elem, .map_lookup_and_delete_elem = htab_lru_map_lookup_and_delete_elem, .map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys, diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 55f83ea09dae..9aabf84afd4b 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -289,13 +289,18 @@ static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock) static DEFINE_PER_CPU(unsigned long, irqsave_flags); -notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock) +static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock) { unsigned long flags; local_irq_save(flags); __bpf_spin_lock(lock); __this_cpu_write(irqsave_flags, flags); +} + +notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock) +{ + __bpf_spin_lock_irqsave(lock); return 0; } @@ -306,13 +311,18 @@ const struct bpf_func_proto bpf_spin_lock_proto = { .arg1_type = ARG_PTR_TO_SPIN_LOCK, }; -notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock) +static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock) { unsigned long flags; flags = __this_cpu_read(irqsave_flags); __bpf_spin_unlock(lock); local_irq_restore(flags); +} + +notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock) +{ + __bpf_spin_unlock_irqrestore(lock); return 0; } @@ -333,9 +343,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src, else lock = dst + map->spin_lock_off; preempt_disable(); - ____bpf_spin_lock(lock); + __bpf_spin_lock_irqsave(lock); copy_map_value(map, dst, src); - ____bpf_spin_unlock(lock); + __bpf_spin_unlock_irqrestore(lock); preempt_enable(); } @@ -393,8 +403,6 @@ const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = { }; #ifdef CONFIG_CGROUP_BPF -DECLARE_PER_CPU(struct bpf_cgroup_storage_info, - bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]); BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags) { @@ -403,17 +411,13 @@ BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags) * verifier checks that its value is correct. */ enum bpf_cgroup_storage_type stype = cgroup_storage_type(map); - struct bpf_cgroup_storage *storage = NULL; + struct bpf_cgroup_storage *storage; + struct bpf_cg_run_ctx *ctx; void *ptr; - int i; - for (i = BPF_CGROUP_STORAGE_NEST_MAX - 1; i >= 0; i--) { - if (likely(this_cpu_read(bpf_cgroup_storage_info[i].task) != current)) - continue; - - storage = this_cpu_read(bpf_cgroup_storage_info[i].storage[stype]); - break; - } + /* get current cgroup storage from BPF run context */ + ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); + storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; @@ -914,6 +918,20 @@ fmt_str: num_spec++; continue; + } else if (fmt[i] == 'c') { + if (!tmp_buf) + goto nocopy_fmt; + + if (tmp_buf_end == tmp_buf) { + err = -ENOSPC; + goto out; + } + + *tmp_buf = raw_args[num_spec]; + tmp_buf++; + num_spec++; + + continue; } sizeof_cur_arg = sizeof(int); @@ -999,11 +1017,327 @@ const struct bpf_func_proto bpf_snprintf_proto = { .arg5_type = ARG_CONST_SIZE_OR_ZERO, }; +/* BPF map elements can contain 'struct bpf_timer'. + * Such map owns all of its BPF timers. + * 'struct bpf_timer' is allocated as part of map element allocation + * and it's zero initialized. + * That space is used to keep 'struct bpf_timer_kern'. + * bpf_timer_init() allocates 'struct bpf_hrtimer', inits hrtimer, and + * remembers 'struct bpf_map *' pointer it's part of. + * bpf_timer_set_callback() increments prog refcnt and assign bpf callback_fn. + * bpf_timer_start() arms the timer. + * If user space reference to a map goes to zero at this point + * ops->map_release_uref callback is responsible for cancelling the timers, + * freeing their memory, and decrementing prog's refcnts. + * bpf_timer_cancel() cancels the timer and decrements prog's refcnt. + * Inner maps can contain bpf timers as well. ops->map_release_uref is + * freeing the timers when inner map is replaced or deleted by user space. + */ +struct bpf_hrtimer { + struct hrtimer timer; + struct bpf_map *map; + struct bpf_prog *prog; + void __rcu *callback_fn; + void *value; +}; + +/* the actual struct hidden inside uapi struct bpf_timer */ +struct bpf_timer_kern { + struct bpf_hrtimer *timer; + /* bpf_spin_lock is used here instead of spinlock_t to make + * sure that it always fits into space resereved by struct bpf_timer + * regardless of LOCKDEP and spinlock debug flags. + */ + struct bpf_spin_lock lock; +} __attribute__((aligned(8))); + +static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running); + +static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer) +{ + struct bpf_hrtimer *t = container_of(hrtimer, struct bpf_hrtimer, timer); + struct bpf_map *map = t->map; + void *value = t->value; + void *callback_fn; + void *key; + u32 idx; + + callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held()); + if (!callback_fn) + goto out; + + /* bpf_timer_cb() runs in hrtimer_run_softirq. It doesn't migrate and + * cannot be preempted by another bpf_timer_cb() on the same cpu. + * Remember the timer this callback is servicing to prevent + * deadlock if callback_fn() calls bpf_timer_cancel() or + * bpf_map_delete_elem() on the same timer. + */ + this_cpu_write(hrtimer_running, t); + if (map->map_type == BPF_MAP_TYPE_ARRAY) { + struct bpf_array *array = container_of(map, struct bpf_array, map); + + /* compute the key */ + idx = ((char *)value - array->value) / array->elem_size; + key = &idx; + } else { /* hash or lru */ + key = value - round_up(map->key_size, 8); + } + + BPF_CAST_CALL(callback_fn)((u64)(long)map, (u64)(long)key, + (u64)(long)value, 0, 0); + /* The verifier checked that return value is zero. */ + + this_cpu_write(hrtimer_running, NULL); +out: + return HRTIMER_NORESTART; +} + +BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map, + u64, flags) +{ + clockid_t clockid = flags & (MAX_CLOCKS - 1); + struct bpf_hrtimer *t; + int ret = 0; + + BUILD_BUG_ON(MAX_CLOCKS != 16); + BUILD_BUG_ON(sizeof(struct bpf_timer_kern) > sizeof(struct bpf_timer)); + BUILD_BUG_ON(__alignof__(struct bpf_timer_kern) != __alignof__(struct bpf_timer)); + + if (in_nmi()) + return -EOPNOTSUPP; + + if (flags >= MAX_CLOCKS || + /* similar to timerfd except _ALARM variants are not supported */ + (clockid != CLOCK_MONOTONIC && + clockid != CLOCK_REALTIME && + clockid != CLOCK_BOOTTIME)) + return -EINVAL; + __bpf_spin_lock_irqsave(&timer->lock); + t = timer->timer; + if (t) { + ret = -EBUSY; + goto out; + } + if (!atomic64_read(&map->usercnt)) { + /* maps with timers must be either held by user space + * or pinned in bpffs. + */ + ret = -EPERM; + goto out; + } + /* allocate hrtimer via map_kmalloc to use memcg accounting */ + t = bpf_map_kmalloc_node(map, sizeof(*t), GFP_ATOMIC, map->numa_node); + if (!t) { + ret = -ENOMEM; + goto out; + } + t->value = (void *)timer - map->timer_off; + t->map = map; + t->prog = NULL; + rcu_assign_pointer(t->callback_fn, NULL); + hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT); + t->timer.function = bpf_timer_cb; + timer->timer = t; +out: + __bpf_spin_unlock_irqrestore(&timer->lock); + return ret; +} + +static const struct bpf_func_proto bpf_timer_init_proto = { + .func = bpf_timer_init, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_TIMER, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, +}; + +BPF_CALL_3(bpf_timer_set_callback, struct bpf_timer_kern *, timer, void *, callback_fn, + struct bpf_prog_aux *, aux) +{ + struct bpf_prog *prev, *prog = aux->prog; + struct bpf_hrtimer *t; + int ret = 0; + + if (in_nmi()) + return -EOPNOTSUPP; + __bpf_spin_lock_irqsave(&timer->lock); + t = timer->timer; + if (!t) { + ret = -EINVAL; + goto out; + } + if (!atomic64_read(&t->map->usercnt)) { + /* maps with timers must be either held by user space + * or pinned in bpffs. Otherwise timer might still be + * running even when bpf prog is detached and user space + * is gone, since map_release_uref won't ever be called. + */ + ret = -EPERM; + goto out; + } + prev = t->prog; + if (prev != prog) { + /* Bump prog refcnt once. Every bpf_timer_set_callback() + * can pick different callback_fn-s within the same prog. + */ + prog = bpf_prog_inc_not_zero(prog); + if (IS_ERR(prog)) { + ret = PTR_ERR(prog); + goto out; + } + if (prev) + /* Drop prev prog refcnt when swapping with new prog */ + bpf_prog_put(prev); + t->prog = prog; + } + rcu_assign_pointer(t->callback_fn, callback_fn); +out: + __bpf_spin_unlock_irqrestore(&timer->lock); + return ret; +} + +static const struct bpf_func_proto bpf_timer_set_callback_proto = { + .func = bpf_timer_set_callback, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_TIMER, + .arg2_type = ARG_PTR_TO_FUNC, +}; + +BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, flags) +{ + struct bpf_hrtimer *t; + int ret = 0; + + if (in_nmi()) + return -EOPNOTSUPP; + if (flags) + return -EINVAL; + __bpf_spin_lock_irqsave(&timer->lock); + t = timer->timer; + if (!t || !t->prog) { + ret = -EINVAL; + goto out; + } + hrtimer_start(&t->timer, ns_to_ktime(nsecs), HRTIMER_MODE_REL_SOFT); +out: + __bpf_spin_unlock_irqrestore(&timer->lock); + return ret; +} + +static const struct bpf_func_proto bpf_timer_start_proto = { + .func = bpf_timer_start, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_TIMER, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, +}; + +static void drop_prog_refcnt(struct bpf_hrtimer *t) +{ + struct bpf_prog *prog = t->prog; + + if (prog) { + bpf_prog_put(prog); + t->prog = NULL; + rcu_assign_pointer(t->callback_fn, NULL); + } +} + +BPF_CALL_1(bpf_timer_cancel, struct bpf_timer_kern *, timer) +{ + struct bpf_hrtimer *t; + int ret = 0; + + if (in_nmi()) + return -EOPNOTSUPP; + __bpf_spin_lock_irqsave(&timer->lock); + t = timer->timer; + if (!t) { + ret = -EINVAL; + goto out; + } + if (this_cpu_read(hrtimer_running) == t) { + /* If bpf callback_fn is trying to bpf_timer_cancel() + * its own timer the hrtimer_cancel() will deadlock + * since it waits for callback_fn to finish + */ + ret = -EDEADLK; + goto out; + } + drop_prog_refcnt(t); +out: + __bpf_spin_unlock_irqrestore(&timer->lock); + /* Cancel the timer and wait for associated callback to finish + * if it was running. + */ + ret = ret ?: hrtimer_cancel(&t->timer); + return ret; +} + +static const struct bpf_func_proto bpf_timer_cancel_proto = { + .func = bpf_timer_cancel, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_TIMER, +}; + +/* This function is called by map_delete/update_elem for individual element and + * by ops->map_release_uref when the user space reference to a map reaches zero. + */ +void bpf_timer_cancel_and_free(void *val) +{ + struct bpf_timer_kern *timer = val; + struct bpf_hrtimer *t; + + /* Performance optimization: read timer->timer without lock first. */ + if (!READ_ONCE(timer->timer)) + return; + + __bpf_spin_lock_irqsave(&timer->lock); + /* re-read it under lock */ + t = timer->timer; + if (!t) + goto out; + drop_prog_refcnt(t); + /* The subsequent bpf_timer_start/cancel() helpers won't be able to use + * this timer, since it won't be initialized. + */ + timer->timer = NULL; +out: + __bpf_spin_unlock_irqrestore(&timer->lock); + if (!t) + return; + /* Cancel the timer and wait for callback to complete if it was running. + * If hrtimer_cancel() can be safely called it's safe to call kfree(t) + * right after for both preallocated and non-preallocated maps. + * The timer->timer = NULL was already done and no code path can + * see address 't' anymore. + * + * Check that bpf_map_delete/update_elem() wasn't called from timer + * callback_fn. In such case don't call hrtimer_cancel() (since it will + * deadlock) and don't call hrtimer_try_to_cancel() (since it will just + * return -1). Though callback_fn is still running on this cpu it's + * safe to do kfree(t) because bpf_timer_cb() read everything it needed + * from 't'. The bpf subprog callback_fn won't be able to access 't', + * since timer->timer = NULL was already done. The timer will be + * effectively cancelled because bpf_timer_cb() will return + * HRTIMER_NORESTART. + */ + if (this_cpu_read(hrtimer_running) != t) + hrtimer_cancel(&t->timer); + kfree(t); +} + const struct bpf_func_proto bpf_get_current_task_proto __weak; +const struct bpf_func_proto bpf_get_current_task_btf_proto __weak; const struct bpf_func_proto bpf_probe_read_user_proto __weak; const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_proto __weak; const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak; +const struct bpf_func_proto bpf_task_pt_regs_proto __weak; const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) @@ -1065,6 +1399,14 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_per_cpu_ptr_proto; case BPF_FUNC_this_cpu_ptr: return &bpf_this_cpu_ptr_proto; + case BPF_FUNC_timer_init: + return &bpf_timer_init_proto; + case BPF_FUNC_timer_set_callback: + return &bpf_timer_set_callback_proto; + case BPF_FUNC_timer_start: + return &bpf_timer_start_proto; + case BPF_FUNC_timer_cancel: + return &bpf_timer_cancel_proto; default: break; } @@ -1077,6 +1419,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return bpf_get_trace_printk_proto(); case BPF_FUNC_get_current_task: return &bpf_get_current_task_proto; + case BPF_FUNC_get_current_task_btf: + return &bpf_get_current_task_btf_proto; case BPF_FUNC_probe_read_user: return &bpf_probe_read_user_proto; case BPF_FUNC_probe_read_kernel: @@ -1091,6 +1435,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_snprintf_btf_proto; case BPF_FUNC_snprintf: return &bpf_snprintf_proto; + case BPF_FUNC_task_pt_regs: + return &bpf_task_pt_regs_proto; default: return NULL; } diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index bd11db9774c3..035e9e3a7132 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -1,6 +1,7 @@ //SPDX-License-Identifier: GPL-2.0 #include <linux/bpf-cgroup.h> #include <linux/bpf.h> +#include <linux/bpf_local_storage.h> #include <linux/btf.h> #include <linux/bug.h> #include <linux/filter.h> @@ -11,9 +12,6 @@ #ifdef CONFIG_CGROUP_BPF -DEFINE_PER_CPU(struct bpf_cgroup_storage_info, - bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]); - #include "../cgroup/cgroup-internal.h" #define LOCAL_STORAGE_CREATE_FLAG_MASK \ @@ -173,7 +171,7 @@ static int cgroup_storage_update_elem(struct bpf_map *map, void *key, return -ENOMEM; memcpy(&new->data[0], value, map->value_size); - check_and_init_map_lock(map, new->data); + check_and_init_map_value(map, new->data); new = xchg(&storage->buf, new); kfree_rcu(new, rcu); @@ -286,9 +284,17 @@ enoent: static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr) { + __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE; int numa_node = bpf_map_attr_numa_node(attr); struct bpf_cgroup_storage_map *map; + /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu + * is the same as other local storages. + */ + if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) + max_value_size = min_t(__u32, max_value_size, + PCPU_MIN_UNIT_SIZE); + if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) && attr->key_size != sizeof(__u64)) return ERR_PTR(-EINVAL); @@ -296,7 +302,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr) if (attr->value_size == 0) return ERR_PTR(-EINVAL); - if (attr->value_size > PAGE_SIZE) + if (attr->value_size > max_value_size) return ERR_PTR(-E2BIG); if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK || @@ -409,7 +415,7 @@ static int cgroup_storage_check_btf(const struct bpf_map *map, static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *key, struct seq_file *m) { - enum bpf_cgroup_storage_type stype = cgroup_storage_type(map); + enum bpf_cgroup_storage_type stype; struct bpf_cgroup_storage *storage; int cpu; @@ -509,7 +515,7 @@ struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog, map->numa_node); if (!storage->buf) goto enomem; - check_and_init_map_lock(map, storage->buf->data); + check_and_init_map_value(map, storage->buf->data); } else { storage->percpu_buf = bpf_map_alloc_percpu(map, size, 8, gfp); if (!storage->percpu_buf) diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 39ab0b68cade..5cd8f5277279 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -3,6 +3,7 @@ */ #include <linux/slab.h> #include <linux/bpf.h> +#include <linux/btf.h> #include "map_in_map.h" @@ -50,6 +51,11 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) inner_map_meta->map_flags = inner_map->map_flags; inner_map_meta->max_entries = inner_map->max_entries; inner_map_meta->spin_lock_off = inner_map->spin_lock_off; + inner_map_meta->timer_off = inner_map->timer_off; + if (inner_map->btf) { + btf_get(inner_map->btf); + inner_map_meta->btf = inner_map->btf; + } /* Misc members not needed in bpf_map_meta_equal() check. */ inner_map_meta->ops = inner_map->ops; @@ -65,6 +71,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) void bpf_map_meta_free(struct bpf_map *map_meta) { + btf_put(map_meta->btf); kfree(map_meta); } @@ -75,6 +82,7 @@ bool bpf_map_meta_equal(const struct bpf_map *meta0, return meta0->map_type == meta1->map_type && meta0->key_size == meta1->key_size && meta0->value_size == meta1->value_size && + meta0->timer_off == meta1->timer_off && meta0->map_flags == meta1->map_flags; } diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 6fbc2abe9c91..6e75bbee39f0 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -63,7 +63,8 @@ static inline int stack_map_data_size(struct bpf_map *map) static int prealloc_elems_and_freelist(struct bpf_stack_map *smap) { - u32 elem_size = sizeof(struct stack_map_bucket) + smap->map.value_size; + u64 elem_size = sizeof(struct stack_map_bucket) + + (u64)smap->map.value_size; int err; smap->elems = bpf_map_area_alloc(elem_size * smap->map.max_entries, @@ -179,7 +180,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, * with build_id. */ if (!user || !current || !current->mm || irq_work_busy || - !mmap_read_trylock_non_owner(current->mm)) { + !mmap_read_trylock(current->mm)) { /* cannot access current->mm, fall back to ips */ for (i = 0; i < trace_nr; i++) { id_offs[i].status = BPF_STACK_BUILD_ID_IP; @@ -204,9 +205,15 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, } if (!work) { - mmap_read_unlock_non_owner(current->mm); + mmap_read_unlock(current->mm); } else { work->mm = current->mm; + + /* The lock will be released once we're out of interrupt + * context. Tell lockdep that we've released it now so + * it doesn't complain that we forgot to release it. + */ + rwsem_release(¤t->mm->mmap_lock.dep_map, _RET_IP_); irq_work_queue(&work->irq_work); } } @@ -530,14 +537,12 @@ BPF_CALL_4(bpf_get_task_stack, struct task_struct *, task, void *, buf, return res; } -BTF_ID_LIST_SINGLE(bpf_get_task_stack_btf_ids, struct, task_struct) - const struct bpf_func_proto bpf_get_task_stack_proto = { .func = bpf_get_task_stack, .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_BTF_ID, - .arg1_btf_id = &bpf_get_task_stack_btf_ids[0], + .arg1_btf_id = &btf_task_struct_ids[0], .arg2_type = ARG_PTR_TO_UNINIT_MEM, .arg3_type = ARG_CONST_SIZE_OR_ZERO, .arg4_type = ARG_ANYTHING, diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index e343f158e556..1cad6979a0d0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -260,8 +260,8 @@ static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, copy_map_value_locked(map, value, ptr, true); else copy_map_value(map, value, ptr); - /* mask lock, since value wasn't zero inited */ - check_and_init_map_lock(map, value); + /* mask lock and timer, since value wasn't zero inited */ + check_and_init_map_value(map, value); } rcu_read_unlock(); } @@ -543,8 +543,10 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) { array = container_of(map, struct bpf_array, map); - type = array->aux->type; - jited = array->aux->jited; + spin_lock(&array->aux->owner.lock); + type = array->aux->owner.type; + jited = array->aux->owner.jited; + spin_unlock(&array->aux->owner.lock); } seq_printf(m, @@ -623,7 +625,8 @@ static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) struct bpf_map *map = filp->private_data; int err; - if (!map->ops->map_mmap || map_value_has_spin_lock(map)) + if (!map->ops->map_mmap || map_value_has_spin_lock(map) || + map_value_has_timer(map)) return -ENOTSUPP; if (!(vma->vm_flags & VM_SHARED)) @@ -793,6 +796,16 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, } } + map->timer_off = btf_find_timer(btf, value_type); + if (map_value_has_timer(map)) { + if (map->map_flags & BPF_F_RDONLY_PROG) + return -EACCES; + if (map->map_type != BPF_MAP_TYPE_HASH && + map->map_type != BPF_MAP_TYPE_LRU_HASH && + map->map_type != BPF_MAP_TYPE_ARRAY) + return -EOPNOTSUPP; + } + if (map->ops->map_check_btf) ret = map->ops->map_check_btf(map, btf, key_type, value_type); @@ -844,6 +857,7 @@ static int map_create(union bpf_attr *attr) mutex_init(&map->freeze_mutex); map->spin_lock_off = -EINVAL; + map->timer_off = -EINVAL; if (attr->btf_key_type_id || attr->btf_value_type_id || /* Even the map's value is a kernel's struct, * the bpf_prog.o must have BTF to begin with @@ -1001,7 +1015,7 @@ int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) static void *__bpf_copy_key(void __user *ukey, u64 key_size) { if (key_size) - return memdup_user(ukey, key_size); + return vmemdup_user(ukey, key_size); if (ukey) return ERR_PTR(-EINVAL); @@ -1012,7 +1026,7 @@ static void *__bpf_copy_key(void __user *ukey, u64 key_size) static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) { if (key_size) - return memdup_bpfptr(ukey, key_size); + return kvmemdup_bpfptr(ukey, key_size); if (!bpfptr_is_null(ukey)) return ERR_PTR(-EINVAL); @@ -1064,7 +1078,7 @@ static int map_lookup_elem(union bpf_attr *attr) value_size = bpf_map_value_size(map); err = -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; @@ -1079,9 +1093,9 @@ static int map_lookup_elem(union bpf_attr *attr) err = 0; free_value: - kfree(value); + kvfree(value); free_key: - kfree(key); + kvfree(key); err_put: fdput(f); return err; @@ -1125,16 +1139,10 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) goto err_put; } - if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || - map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || - map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) - value_size = round_up(map->value_size, 8) * num_possible_cpus(); - else - value_size = map->value_size; + value_size = bpf_map_value_size(map); err = -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; @@ -1145,9 +1153,9 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) err = bpf_map_update_value(map, f, key, value, attr->flags); free_value: - kfree(value); + kvfree(value); free_key: - kfree(key); + kvfree(key); err_put: fdput(f); return err; @@ -1199,7 +1207,7 @@ static int map_delete_elem(union bpf_attr *attr) bpf_enable_instrumentation(); maybe_wait_bpf_programs(map); out: - kfree(key); + kvfree(key); err_put: fdput(f); return err; @@ -1241,7 +1249,7 @@ static int map_get_next_key(union bpf_attr *attr) } err = -ENOMEM; - next_key = kmalloc(map->key_size, GFP_USER); + next_key = kvmalloc(map->key_size, GFP_USER); if (!next_key) goto free_key; @@ -1264,9 +1272,9 @@ out: err = 0; free_next_key: - kfree(next_key); + kvfree(next_key); free_key: - kfree(key); + kvfree(key); err_put: fdput(f); return err; @@ -1293,7 +1301,7 @@ int generic_map_delete_batch(struct bpf_map *map, if (!max_count) return 0; - key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); if (!key) return -ENOMEM; @@ -1320,7 +1328,7 @@ int generic_map_delete_batch(struct bpf_map *map, if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) err = -EFAULT; - kfree(key); + kvfree(key); return err; } @@ -1331,12 +1339,11 @@ int generic_map_update_batch(struct bpf_map *map, void __user *values = u64_to_user_ptr(attr->batch.values); void __user *keys = u64_to_user_ptr(attr->batch.keys); u32 value_size, cp, max_count; - int ufd = attr->map_fd; + int ufd = attr->batch.map_fd; void *key, *value; struct fd f; int err = 0; - f = fdget(ufd); if (attr->batch.elem_flags & ~BPF_F_LOCK) return -EINVAL; @@ -1351,16 +1358,17 @@ int generic_map_update_batch(struct bpf_map *map, if (!max_count) return 0; - key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); if (!key) return -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) { - kfree(key); + kvfree(key); return -ENOMEM; } + f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */ for (cp = 0; cp < max_count; cp++) { err = -EFAULT; if (copy_from_user(key, keys + cp * map->key_size, @@ -1378,8 +1386,9 @@ int generic_map_update_batch(struct bpf_map *map, if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) err = -EFAULT; - kfree(value); - kfree(key); + kvfree(value); + kvfree(key); + fdput(f); return err; } @@ -1413,13 +1422,13 @@ int generic_map_lookup_batch(struct bpf_map *map, if (put_user(0, &uattr->batch.count)) return -EFAULT; - buf_prevkey = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); if (!buf_prevkey) return -ENOMEM; - buf = kmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); + buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); if (!buf) { - kfree(buf_prevkey); + kvfree(buf_prevkey); return -ENOMEM; } @@ -1479,8 +1488,8 @@ int generic_map_lookup_batch(struct bpf_map *map, err = -EFAULT; free_buf: - kfree(buf_prevkey); - kfree(buf); + kvfree(buf_prevkey); + kvfree(buf); return err; } @@ -1535,7 +1544,7 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr) value_size = bpf_map_value_size(map); err = -ENOMEM; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; @@ -1567,9 +1576,9 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr) err = 0; free_value: - kfree(value); + kvfree(value); free_key: - kfree(key); + kvfree(key); err_put: fdput(f); return err; @@ -1591,7 +1600,8 @@ static int map_freeze(const union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); - if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { + if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || + map_value_has_timer(map)) { fdput(f); return -ENOTSUPP; } @@ -1699,6 +1709,8 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog) void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) { + unsigned long flags; + /* cBPF to eBPF migrations are currently not in the idr store. * Offloaded programs are removed from the store when their device * disappears - even if someone grabs an fd to them they are unusable, @@ -1708,7 +1720,7 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) return; if (do_idr_lock) - spin_lock_bh(&prog_idr_lock); + spin_lock_irqsave(&prog_idr_lock, flags); else __acquire(&prog_idr_lock); @@ -1716,7 +1728,7 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) prog->aux->id = 0; if (do_idr_lock) - spin_unlock_bh(&prog_idr_lock); + spin_unlock_irqrestore(&prog_idr_lock, flags); else __release(&prog_idr_lock); } @@ -1752,14 +1764,32 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) } } +static void bpf_prog_put_deferred(struct work_struct *work) +{ + struct bpf_prog_aux *aux; + struct bpf_prog *prog; + + aux = container_of(work, struct bpf_prog_aux, work); + prog = aux->prog; + perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); + bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); + __bpf_prog_put_noref(prog, true); +} + static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) { - if (atomic64_dec_and_test(&prog->aux->refcnt)) { - perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); - bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); + struct bpf_prog_aux *aux = prog->aux; + + if (atomic64_dec_and_test(&aux->refcnt)) { /* bpf_prog_free_id() must be called first */ bpf_prog_free_id(prog, do_idr_lock); - __bpf_prog_put_noref(prog, true); + + if (in_irq() || irqs_disabled()) { + INIT_WORK(&aux->work, bpf_prog_put_deferred); + schedule_work(&aux->work); + } else { + bpf_prog_put_deferred(&aux->work); + } } } @@ -2873,6 +2903,79 @@ static const struct bpf_link_ops bpf_raw_tp_link_lops = { .fill_link_info = bpf_raw_tp_link_fill_link_info, }; +#ifdef CONFIG_PERF_EVENTS +struct bpf_perf_link { + struct bpf_link link; + struct file *perf_file; +}; + +static void bpf_perf_link_release(struct bpf_link *link) +{ + struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); + struct perf_event *event = perf_link->perf_file->private_data; + + perf_event_free_bpf_prog(event); + fput(perf_link->perf_file); +} + +static void bpf_perf_link_dealloc(struct bpf_link *link) +{ + struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); + + kfree(perf_link); +} + +static const struct bpf_link_ops bpf_perf_link_lops = { + .release = bpf_perf_link_release, + .dealloc = bpf_perf_link_dealloc, +}; + +static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_link_primer link_primer; + struct bpf_perf_link *link; + struct perf_event *event; + struct file *perf_file; + int err; + + if (attr->link_create.flags) + return -EINVAL; + + perf_file = perf_event_get(attr->link_create.target_fd); + if (IS_ERR(perf_file)) + return PTR_ERR(perf_file); + + link = kzalloc(sizeof(*link), GFP_USER); + if (!link) { + err = -ENOMEM; + goto out_put_file; + } + bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); + link->perf_file = perf_file; + + err = bpf_link_prime(&link->link, &link_primer); + if (err) { + kfree(link); + goto out_put_file; + } + + event = perf_file->private_data; + err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); + if (err) { + bpf_link_cleanup(&link_primer); + goto out_put_file; + } + /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ + bpf_prog_inc(prog); + + return bpf_link_settle(&link_primer); + +out_put_file: + fput(perf_file); + return err; +} +#endif /* CONFIG_PERF_EVENTS */ + #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd static int bpf_raw_tracepoint_open(const union bpf_attr *attr) @@ -4114,15 +4217,26 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) if (ret) goto out; - if (prog->type == BPF_PROG_TYPE_EXT) { + switch (prog->type) { + case BPF_PROG_TYPE_EXT: ret = tracing_bpf_link_attach(attr, uattr, prog); goto out; - } - - ptype = attach_type_to_prog_type(attr->link_create.attach_type); - if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) { - ret = -EINVAL; - goto out; + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_KPROBE: + case BPF_PROG_TYPE_TRACEPOINT: + if (attr->link_create.attach_type != BPF_PERF_EVENT) { + ret = -EINVAL; + goto out; + } + ptype = prog->type; + break; + default: + ptype = attach_type_to_prog_type(attr->link_create.attach_type); + if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) { + ret = -EINVAL; + goto out; + } + break; } switch (ptype) { @@ -4147,6 +4261,13 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) ret = bpf_xdp_link_attach(attr, prog); break; #endif +#ifdef CONFIG_PERF_EVENTS + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_TRACEPOINT: + case BPF_PROG_TYPE_KPROBE: + ret = bpf_perf_link_attach(attr, prog); + break; +#endif default: ret = -EINVAL; } diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index b68cb5d6d6eb..b48750bfba5a 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -525,7 +525,6 @@ static const struct seq_operations task_vma_seq_ops = { }; BTF_ID_LIST(btf_task_file_ids) -BTF_ID(struct, task_struct) BTF_ID(struct, file) BTF_ID(struct, vm_area_struct) @@ -591,19 +590,19 @@ static int __init task_iter_init(void) { int ret; - task_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0]; + task_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0]; ret = bpf_iter_reg_target(&task_reg_info); if (ret) return ret; - task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0]; - task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1]; + task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0]; + task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[0]; ret = bpf_iter_reg_target(&task_file_reg_info); if (ret) return ret; - task_vma_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0]; - task_vma_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[2]; + task_vma_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0]; + task_vma_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1]; return bpf_iter_reg_target(&task_vma_reg_info); } late_initcall(task_iter_init); diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 28a3630c48ee..fe1e857324e6 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -172,7 +172,7 @@ static int register_fentry(struct bpf_trampoline *tr, void *new_addr) } static struct bpf_tramp_progs * -bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total) +bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total, bool *ip_arg) { const struct bpf_prog_aux *aux; struct bpf_tramp_progs *tprogs; @@ -189,8 +189,10 @@ bpf_trampoline_get_progs(const struct bpf_trampoline *tr, int *total) *total += tr->progs_cnt[kind]; progs = tprogs[kind].progs; - hlist_for_each_entry(aux, &tr->progs_hlist[kind], tramp_hlist) + hlist_for_each_entry(aux, &tr->progs_hlist[kind], tramp_hlist) { + *ip_arg |= aux->prog->call_get_func_ip; *progs++ = aux->prog; + } } return tprogs; } @@ -333,9 +335,10 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr) struct bpf_tramp_image *im; struct bpf_tramp_progs *tprogs; u32 flags = BPF_TRAMP_F_RESTORE_REGS; + bool ip_arg = false; int err, total; - tprogs = bpf_trampoline_get_progs(tr, &total); + tprogs = bpf_trampoline_get_progs(tr, &total, &ip_arg); if (IS_ERR(tprogs)) return PTR_ERR(tprogs); @@ -357,6 +360,9 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr) tprogs[BPF_TRAMP_MODIFY_RETURN].nr_progs) flags = BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_SKIP_FRAME; + if (ip_arg) + flags |= BPF_TRAMP_F_IP_ARG; + err = arch_prepare_bpf_trampoline(im, im->image, im->image + PAGE_SIZE, &tr->func.model, flags, tprogs, tr->func.addr); @@ -542,7 +548,7 @@ static void notrace inc_misses_counter(struct bpf_prog *prog) u64_stats_update_end(&stats->syncp); } -/* The logic is similar to BPF_PROG_RUN, but with an explicit +/* The logic is similar to bpf_prog_run(), but with an explicit * rcu_read_lock() and migrate_disable() which are required * for the trampoline. The macro is split into * call __bpf_prog_enter diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 381d3d6f24bc..de006552be8a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -255,6 +255,7 @@ struct bpf_call_arg_meta { int mem_size; u64 msize_max_value; int ref_obj_id; + int map_uid; int func_id; struct btf *btf; u32 btf_id; @@ -734,6 +735,10 @@ static void print_verifier_state(struct bpf_verifier_env *env, if (state->refs[i].id) verbose(env, ",%d", state->refs[i].id); } + if (state->in_callback_fn) + verbose(env, " cb"); + if (state->in_async_callback_fn) + verbose(env, " async_cb"); verbose(env, "\n"); } @@ -1135,6 +1140,10 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg) if (map->inner_map_meta) { reg->type = CONST_PTR_TO_MAP; reg->map_ptr = map->inner_map_meta; + /* transfer reg's id which is unique for every map_lookup_elem + * as UID of the inner map. + */ + reg->map_uid = reg->id; } else if (map->map_type == BPF_MAP_TYPE_XSKMAP) { reg->type = PTR_TO_XDP_SOCK; } else if (map->map_type == BPF_MAP_TYPE_SOCKMAP || @@ -1522,6 +1531,54 @@ static void init_func_state(struct bpf_verifier_env *env, init_reg_state(env, state); } +/* Similar to push_stack(), but for async callbacks */ +static struct bpf_verifier_state *push_async_cb(struct bpf_verifier_env *env, + int insn_idx, int prev_insn_idx, + int subprog) +{ + struct bpf_verifier_stack_elem *elem; + struct bpf_func_state *frame; + + elem = kzalloc(sizeof(struct bpf_verifier_stack_elem), GFP_KERNEL); + if (!elem) + goto err; + + elem->insn_idx = insn_idx; + elem->prev_insn_idx = prev_insn_idx; + elem->next = env->head; + elem->log_pos = env->log.len_used; + env->head = elem; + env->stack_size++; + if (env->stack_size > BPF_COMPLEXITY_LIMIT_JMP_SEQ) { + verbose(env, + "The sequence of %d jumps is too complex for async cb.\n", + env->stack_size); + goto err; + } + /* Unlike push_stack() do not copy_verifier_state(). + * The caller state doesn't matter. + * This is async callback. It starts in a fresh stack. + * Initialize it similar to do_check_common(). + */ + elem->st.branches = 1; + frame = kzalloc(sizeof(*frame), GFP_KERNEL); + if (!frame) + goto err; + init_func_state(env, frame, + BPF_MAIN_FUNC /* callsite */, + 0 /* frameno within this callchain */, + subprog /* subprog number within this prog */); + elem->st.frame[0] = frame; + return &elem->st; +err: + free_verifier_state(env->cur_state, true); + env->cur_state = NULL; + /* pop all elements and return */ + while (!pop_stack(env, NULL, NULL, false)); + return NULL; +} + + enum reg_arg_type { SRC_OP, /* register is used as source operand */ DST_OP, /* register is used as destination operand */ @@ -3217,6 +3274,15 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, return -EACCES; } } + if (map_value_has_timer(map)) { + u32 t = map->timer_off; + + if (reg->smin_value + off < t + sizeof(struct bpf_timer) && + t < reg->umax_value + off + size) { + verbose(env, "bpf_timer cannot be accessed directly by load/store\n"); + return -EACCES; + } + } return err; } @@ -3619,6 +3685,8 @@ process_func: continue_func: subprog_end = subprog[idx + 1].start; for (; i < subprog_end; i++) { + int next_insn; + if (!bpf_pseudo_call(insn + i) && !bpf_pseudo_func(insn + i)) continue; /* remember insn and function to return to */ @@ -3626,13 +3694,22 @@ continue_func: ret_prog[frame] = idx; /* find the callee */ - i = i + insn[i].imm + 1; - idx = find_subprog(env, i); + next_insn = i + insn[i].imm + 1; + idx = find_subprog(env, next_insn); if (idx < 0) { WARN_ONCE(1, "verifier bug. No program starts at insn %d\n", - i); + next_insn); return -EFAULT; } + if (subprog[idx].is_async_cb) { + if (subprog[idx].has_tail_call) { + verbose(env, "verifier bug. subprog has tail_call and async cb\n"); + return -EFAULT; + } + /* async callbacks don't increase bpf prog stack size */ + continue; + } + i = next_insn; if (subprog[idx].has_tail_call) tail_call_reachable = true; @@ -4634,6 +4711,54 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, return 0; } +static int process_timer_func(struct bpf_verifier_env *env, int regno, + struct bpf_call_arg_meta *meta) +{ + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; + bool is_const = tnum_is_const(reg->var_off); + struct bpf_map *map = reg->map_ptr; + u64 val = reg->var_off.value; + + if (!is_const) { + verbose(env, + "R%d doesn't have constant offset. bpf_timer has to be at the constant offset\n", + regno); + return -EINVAL; + } + if (!map->btf) { + verbose(env, "map '%s' has to have BTF in order to use bpf_timer\n", + map->name); + return -EINVAL; + } + if (!map_value_has_timer(map)) { + if (map->timer_off == -E2BIG) + verbose(env, + "map '%s' has more than one 'struct bpf_timer'\n", + map->name); + else if (map->timer_off == -ENOENT) + verbose(env, + "map '%s' doesn't have 'struct bpf_timer'\n", + map->name); + else + verbose(env, + "map '%s' is not a struct type or bpf_timer is mangled\n", + map->name); + return -EINVAL; + } + if (map->timer_off != val + reg->off) { + verbose(env, "off %lld doesn't point to 'struct bpf_timer' that is at %d\n", + val + reg->off, map->timer_off); + return -EINVAL; + } + if (meta->map_ptr) { + verbose(env, "verifier bug. Two map pointers in a timer helper\n"); + return -EFAULT; + } + meta->map_uid = reg->map_uid; + meta->map_ptr = map; + return 0; +} + static bool arg_type_is_mem_ptr(enum bpf_arg_type type) { return type == ARG_PTR_TO_MEM || @@ -4766,6 +4891,7 @@ static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_PER static const struct bpf_reg_types func_ptr_types = { .types = { PTR_TO_FUNC } }; static const struct bpf_reg_types stack_ptr_types = { .types = { PTR_TO_STACK } }; static const struct bpf_reg_types const_str_ptr_types = { .types = { PTR_TO_MAP_VALUE } }; +static const struct bpf_reg_types timer_types = { .types = { PTR_TO_MAP_VALUE } }; static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_MAP_KEY] = &map_key_value_types, @@ -4797,6 +4923,7 @@ static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_FUNC] = &func_ptr_types, [ARG_PTR_TO_STACK_OR_NULL] = &stack_ptr_types, [ARG_PTR_TO_CONST_STR] = &const_str_ptr_types, + [ARG_PTR_TO_TIMER] = &timer_types, }; static int check_reg_type(struct bpf_verifier_env *env, u32 regno, @@ -4926,7 +5053,29 @@ skip_type_check: if (arg_type == ARG_CONST_MAP_PTR) { /* bpf_map_xxx(map_ptr) call: remember that map_ptr */ + if (meta->map_ptr) { + /* Use map_uid (which is unique id of inner map) to reject: + * inner_map1 = bpf_map_lookup_elem(outer_map, key1) + * inner_map2 = bpf_map_lookup_elem(outer_map, key2) + * if (inner_map1 && inner_map2) { + * timer = bpf_map_lookup_elem(inner_map1); + * if (timer) + * // mismatch would have been allowed + * bpf_timer_init(timer, inner_map2); + * } + * + * Comparing map_ptr is enough to distinguish normal and outer maps. + */ + if (meta->map_ptr != reg->map_ptr || + meta->map_uid != reg->map_uid) { + verbose(env, + "timer pointer in R1 map_uid=%d doesn't match map pointer in R2 map_uid=%d\n", + meta->map_uid, reg->map_uid); + return -EINVAL; + } + } meta->map_ptr = reg->map_ptr; + meta->map_uid = reg->map_uid; } else if (arg_type == ARG_PTR_TO_MAP_KEY) { /* bpf_map_xxx(..., map_ptr, ..., key) call: * check that [key, key + map->key_size) are within @@ -4978,6 +5127,9 @@ skip_type_check: verbose(env, "verifier internal error\n"); return -EFAULT; } + } else if (arg_type == ARG_PTR_TO_TIMER) { + if (process_timer_func(env, regno, meta)) + return -EACCES; } else if (arg_type == ARG_PTR_TO_FUNC) { meta->subprogno = reg->subprogno; } else if (arg_type_is_mem_ptr(arg_type)) { @@ -5150,8 +5302,6 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, case BPF_MAP_TYPE_RINGBUF: if (func_id != BPF_FUNC_ringbuf_output && func_id != BPF_FUNC_ringbuf_reserve && - func_id != BPF_FUNC_ringbuf_submit && - func_id != BPF_FUNC_ringbuf_discard && func_id != BPF_FUNC_ringbuf_query) goto error; break; @@ -5260,6 +5410,12 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) goto error; break; + case BPF_FUNC_ringbuf_output: + case BPF_FUNC_ringbuf_reserve: + case BPF_FUNC_ringbuf_query: + if (map->map_type != BPF_MAP_TYPE_RINGBUF) + goto error; + break; case BPF_FUNC_get_stackid: if (map->map_type != BPF_MAP_TYPE_STACK_TRACE) goto error; @@ -5593,6 +5749,31 @@ static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn } } + if (insn->code == (BPF_JMP | BPF_CALL) && + insn->imm == BPF_FUNC_timer_set_callback) { + struct bpf_verifier_state *async_cb; + + /* there is no real recursion here. timer callbacks are async */ + env->subprog_info[subprog].is_async_cb = true; + async_cb = push_async_cb(env, env->subprog_info[subprog].start, + *insn_idx, subprog); + if (!async_cb) + return -EFAULT; + callee = async_cb->frame[0]; + callee->async_entry_cnt = caller->async_entry_cnt + 1; + + /* Convert bpf_timer_set_callback() args into timer callback args */ + err = set_callee_state_cb(env, caller, callee, *insn_idx); + if (err) + return err; + + clear_caller_saved_regs(env, caller->regs); + mark_reg_unknown(env, caller->regs, BPF_REG_0); + caller->regs[BPF_REG_0].subreg_def = DEF_NOT_SUBREG; + /* continue with next insn after call */ + return 0; + } + callee = kzalloc(sizeof(*callee), GFP_KERNEL); if (!callee) return -ENOMEM; @@ -5720,6 +5901,35 @@ static int set_map_elem_callback_state(struct bpf_verifier_env *env, return 0; } +static int set_timer_callback_state(struct bpf_verifier_env *env, + struct bpf_func_state *caller, + struct bpf_func_state *callee, + int insn_idx) +{ + struct bpf_map *map_ptr = caller->regs[BPF_REG_1].map_ptr; + + /* bpf_timer_set_callback(struct bpf_timer *timer, void *callback_fn); + * callback_fn(struct bpf_map *map, void *key, void *value); + */ + callee->regs[BPF_REG_1].type = CONST_PTR_TO_MAP; + __mark_reg_known_zero(&callee->regs[BPF_REG_1]); + callee->regs[BPF_REG_1].map_ptr = map_ptr; + + callee->regs[BPF_REG_2].type = PTR_TO_MAP_KEY; + __mark_reg_known_zero(&callee->regs[BPF_REG_2]); + callee->regs[BPF_REG_2].map_ptr = map_ptr; + + callee->regs[BPF_REG_3].type = PTR_TO_MAP_VALUE; + __mark_reg_known_zero(&callee->regs[BPF_REG_3]); + callee->regs[BPF_REG_3].map_ptr = map_ptr; + + /* unused */ + __mark_reg_not_init(env, &callee->regs[BPF_REG_4]); + __mark_reg_not_init(env, &callee->regs[BPF_REG_5]); + callee->in_async_callback_fn = true; + return 0; +} + static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx) { struct bpf_verifier_state *state = env->cur_state; @@ -5933,6 +6143,29 @@ static int check_bpf_snprintf_call(struct bpf_verifier_env *env, return err; } +static int check_get_func_ip(struct bpf_verifier_env *env) +{ + enum bpf_attach_type eatype = env->prog->expected_attach_type; + enum bpf_prog_type type = resolve_prog_type(env->prog); + int func_id = BPF_FUNC_get_func_ip; + + if (type == BPF_PROG_TYPE_TRACING) { + if (eatype != BPF_TRACE_FENTRY && eatype != BPF_TRACE_FEXIT && + eatype != BPF_MODIFY_RETURN) { + verbose(env, "func %s#%d supported only for fentry/fexit/fmod_ret programs\n", + func_id_name(func_id), func_id); + return -ENOTSUPP; + } + return 0; + } else if (type == BPF_PROG_TYPE_KPROBE) { + return 0; + } + + verbose(env, "func %s#%d not supported for program type %d\n", + func_id_name(func_id), func_id, type); + return -ENOTSUPP; +} + static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { @@ -6047,6 +6280,13 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn return -EINVAL; } + if (func_id == BPF_FUNC_timer_set_callback) { + err = __check_func_call(env, insn, insn_idx_p, meta.subprogno, + set_timer_callback_state); + if (err < 0) + return -EINVAL; + } + if (func_id == BPF_FUNC_snprintf) { err = check_bpf_snprintf_call(env, regs); if (err < 0) @@ -6082,6 +6322,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn return -EINVAL; } regs[BPF_REG_0].map_ptr = meta.map_ptr; + regs[BPF_REG_0].map_uid = meta.map_uid; if (fn->ret_type == RET_PTR_TO_MAP_VALUE) { regs[BPF_REG_0].type = PTR_TO_MAP_VALUE; if (map_value_has_spin_lock(meta.map_ptr)) @@ -6203,6 +6444,12 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn if (func_id == BPF_FUNC_get_stackid || func_id == BPF_FUNC_get_stack) env->prog->call_get_stack = true; + if (func_id == BPF_FUNC_get_func_ip) { + if (check_get_func_ip(env)) + return -ENOTSUPP; + env->prog->call_get_func_ip = true; + } + if (changes_data) clear_all_pkt_pointers(env); return 0; @@ -9083,7 +9330,8 @@ static int check_return_code(struct bpf_verifier_env *env) struct tnum range = tnum_range(0, 1); enum bpf_prog_type prog_type = resolve_prog_type(env->prog); int err; - const bool is_subprog = env->cur_state->frame[0]->subprogno; + struct bpf_func_state *frame = env->cur_state->frame[0]; + const bool is_subprog = frame->subprogno; /* LSM and struct_ops func-ptr's return type could be "void" */ if (!is_subprog && @@ -9108,6 +9356,22 @@ static int check_return_code(struct bpf_verifier_env *env) } reg = cur_regs(env) + BPF_REG_0; + + if (frame->in_async_callback_fn) { + /* enforce return zero from async callbacks like timer */ + if (reg->type != SCALAR_VALUE) { + verbose(env, "In async callback the register R0 is not a known value (%s)\n", + reg_type_str[reg->type]); + return -EINVAL; + } + + if (!tnum_in(tnum_const(0), reg->var_off)) { + verbose_invalid_scalar(env, reg, &range, "async callback", "R0"); + return -EINVAL; + } + return 0; + } + if (is_subprog) { if (reg->type != SCALAR_VALUE) { verbose(env, "At subprogram exit the register R0 is not a scalar value (%s)\n", @@ -9322,8 +9586,12 @@ static int visit_func_call_insn(int t, int insn_cnt, init_explored_state(env, t + 1); if (visit_callee) { init_explored_state(env, t); - ret = push_insn(t, t + insns[t].imm + 1, BRANCH, - env, false); + ret = push_insn(t, t + insns[t].imm + 1, BRANCH, env, + /* It's ok to allow recursion from CFG point of + * view. __check_func_call() will do the actual + * check. + */ + bpf_pseudo_func(insns + t)); } return ret; } @@ -9351,6 +9619,13 @@ static int visit_insn(int t, int insn_cnt, struct bpf_verifier_env *env) return DONE_EXPLORING; case BPF_CALL: + if (insns[t].imm == BPF_FUNC_timer_set_callback) + /* Mark this call insn to trigger is_state_visited() check + * before call itself is processed by __check_func_call(). + * Otherwise new async state will be pushed for further + * exploration. + */ + init_explored_state(env, t); return visit_func_call_insn(t, insn_cnt, insns, env, insns[t].src_reg == BPF_PSEUDO_CALL); @@ -9637,6 +9912,8 @@ static int check_btf_line(struct bpf_verifier_env *env, nr_linfo = attr->line_info_cnt; if (!nr_linfo) return 0; + if (nr_linfo > INT_MAX / sizeof(struct bpf_line_info)) + return -EINVAL; rec_size = attr->line_info_rec_size; if (rec_size < MIN_BPF_LINEINFO_SIZE || @@ -10359,9 +10636,25 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) states_cnt++; if (sl->state.insn_idx != insn_idx) goto next; + if (sl->state.branches) { - if (states_maybe_looping(&sl->state, cur) && - states_equal(env, &sl->state, cur)) { + struct bpf_func_state *frame = sl->state.frame[sl->state.curframe]; + + if (frame->in_async_callback_fn && + frame->async_entry_cnt != cur->frame[cur->curframe]->async_entry_cnt) { + /* Different async_entry_cnt means that the verifier is + * processing another entry into async callback. + * Seeing the same state is not an indication of infinite + * loop or infinite recursion. + * But finding the same state doesn't mean that it's safe + * to stop processing the current state. The previous state + * hasn't yet reached bpf_exit, since state.branches > 0. + * Checking in_async_callback_fn alone is not enough either. + * Since the verifier still needs to catch infinite loops + * inside async callbacks. + */ + } else if (states_maybe_looping(&sl->state, cur) && + states_equal(env, &sl->state, cur)) { verbose_linfo(env, insn_idx, "; "); verbose(env, "infinite loop detected at insn %d\n", insn_idx); return -EINVAL; @@ -11410,10 +11703,11 @@ static void convert_pseudo_ld_imm64(struct bpf_verifier_env *env) * insni[off, off + cnt). Adjust corresponding insn_aux_data by copying * [0, off) and [off, end) to new locations, so the patched range stays zero */ -static int adjust_insn_aux_data(struct bpf_verifier_env *env, - struct bpf_prog *new_prog, u32 off, u32 cnt) +static void adjust_insn_aux_data(struct bpf_verifier_env *env, + struct bpf_insn_aux_data *new_data, + struct bpf_prog *new_prog, u32 off, u32 cnt) { - struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; + struct bpf_insn_aux_data *old_data = env->insn_aux_data; struct bpf_insn *insn = new_prog->insnsi; u32 old_seen = old_data[off].seen; u32 prog_len; @@ -11426,12 +11720,9 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, old_data[off].zext_dst = insn_has_def32(env, insn + off + cnt - 1); if (cnt == 1) - return 0; + return; prog_len = new_prog->len; - new_data = vzalloc(array_size(prog_len, - sizeof(struct bpf_insn_aux_data))); - if (!new_data) - return -ENOMEM; + memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off); memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); @@ -11442,7 +11733,6 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, } env->insn_aux_data = new_data; vfree(old_data); - return 0; } static void adjust_subprog_starts(struct bpf_verifier_env *env, u32 off, u32 len) @@ -11477,6 +11767,14 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of const struct bpf_insn *patch, u32 len) { struct bpf_prog *new_prog; + struct bpf_insn_aux_data *new_data = NULL; + + if (len > 1) { + new_data = vzalloc(array_size(env->prog->len + len - 1, + sizeof(struct bpf_insn_aux_data))); + if (!new_data) + return NULL; + } new_prog = bpf_patch_insn_single(env->prog, off, patch, len); if (IS_ERR(new_prog)) { @@ -11484,10 +11782,10 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of verbose(env, "insn %d cannot be patched due to 16-bit range\n", env->insn_aux_data[off].orig_idx); + vfree(new_data); return NULL; } - if (adjust_insn_aux_data(env, new_prog, off, len)) - return NULL; + adjust_insn_aux_data(env, new_data, new_prog, off, len); adjust_subprog_starts(env, off, len); adjust_poke_descs(new_prog, off, len); return new_prog; @@ -12004,6 +12302,10 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) if (is_narrower_load && size < target_size) { u8 shift = bpf_ctx_narrow_access_offset( off, size, size_default) * 8; + if (shift && cnt + 1 >= ARRAY_SIZE(insn_buf)) { + verbose(env, "bpf verifier narrow ctx load misconfigured\n"); + return -EINVAL; + } if (ctx_field_size <= 4) { if (shift) insn_buf[cnt++] = BPF_ALU32_IMM(BPF_RSH, @@ -12092,7 +12394,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) subprog_end = env->subprog_info[i + 1].start; len = subprog_end - subprog_start; - /* BPF_PROG_RUN doesn't call subprogs directly, + /* bpf_prog_run() doesn't call subprogs directly, * hence main prog stats include the runtime of subprogs. * subprogs don't have IDs and not reachable via prog_get_next_id * func[i]->stats will never be accessed and stays NULL @@ -12338,6 +12640,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog; bool expect_blinding = bpf_jit_blinding_enabled(prog); + enum bpf_prog_type prog_type = resolve_prog_type(prog); struct bpf_insn *insn = prog->insnsi; const struct bpf_func_proto *fn; const int insn_cnt = prog->len; @@ -12555,6 +12858,39 @@ static int do_misc_fixups(struct bpf_verifier_env *env) continue; } + if (insn->imm == BPF_FUNC_timer_set_callback) { + /* The verifier will process callback_fn as many times as necessary + * with different maps and the register states prepared by + * set_timer_callback_state will be accurate. + * + * The following use case is valid: + * map1 is shared by prog1, prog2, prog3. + * prog1 calls bpf_timer_init for some map1 elements + * prog2 calls bpf_timer_set_callback for some map1 elements. + * Those that were not bpf_timer_init-ed will return -EINVAL. + * prog3 calls bpf_timer_start for some map1 elements. + * Those that were not both bpf_timer_init-ed and + * bpf_timer_set_callback-ed will return -EINVAL. + */ + struct bpf_insn ld_addrs[2] = { + BPF_LD_IMM64(BPF_REG_3, (long)prog->aux), + }; + + insn_buf[0] = ld_addrs[0]; + insn_buf[1] = ld_addrs[1]; + insn_buf[2] = *insn; + cnt = 3; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + goto patch_call_imm; + } + /* BPF_EMIT_CALL() assumptions in some of the map_gen_lookup * and other inlining handlers are currently limited to 64 bit * only. @@ -12671,6 +13007,21 @@ patch_map_ops_generic: continue; } + /* Implement bpf_get_func_ip inline. */ + if (prog_type == BPF_PROG_TYPE_TRACING && + insn->imm == BPF_FUNC_get_func_ip) { + /* Load IP address from ctx - 8 */ + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8); + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1); + if (!new_prog) + return -ENOMEM; + + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } + patch_call_imm: fn = env->ops->get_func_proto(insn->imm, env->prog); /* all functions that have prototype and verifier allowed @@ -12968,7 +13319,7 @@ BTF_SET_START(btf_non_sleepable_error_inject) /* Three functions below can be called from sleepable and non-sleepable context. * Assume non-sleepable from bpf safety point of view. */ -BTF_ID(func, __add_to_page_cache_locked) +BTF_ID(func, __filemap_add_folio) BTF_ID(func, should_fail_alloc_page) BTF_ID(func, should_failslab) BTF_SET_END(btf_non_sleepable_error_inject) diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index de2c432dee20..35b920328344 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -50,6 +50,8 @@ bool cgroup1_ssid_disabled(int ssid) * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from' * @from: attach to all cgroups of a given task * @tsk: the task to be attached + * + * Return: %0 on success or a negative errno code on failure */ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) { @@ -80,7 +82,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) EXPORT_SYMBOL_GPL(cgroup_attach_task_all); /** - * cgroup_trasnsfer_tasks - move tasks from one cgroup to another + * cgroup_transfer_tasks - move tasks from one cgroup to another * @to: cgroup to which the tasks will be moved * @from: cgroup in which the tasks currently reside * @@ -89,6 +91,8 @@ EXPORT_SYMBOL_GPL(cgroup_attach_task_all); * is guaranteed to be either visible in the source cgroup after the * parent's migration is complete or put into the target cgroup. No task * can slip out of migration through forking. + * + * Return: %0 on success or a negative errno code on failure */ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) { @@ -682,6 +686,8 @@ int proc_cgroupstats_show(struct seq_file *m, void *v) * * Build and fill cgroupstats so that taskstats can export it to user * space. + * + * Return: %0 on success or a negative errno code on failure */ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) { diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 3a0161c21b6b..ea08f01d0111 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -68,6 +68,14 @@ #define CGROUP_FILE_NOTIFY_MIN_INTV DIV_ROUND_UP(HZ, 100) /* + * To avoid confusing the compiler (and generating warnings) with code + * that attempts to access what would be a 0-element array (i.e. sized + * to a potentially empty array when CGROUP_SUBSYS_COUNT == 0), this + * constant expression can be added. + */ +#define CGROUP_HAS_SUBSYS_CONFIG (CGROUP_SUBSYS_COUNT > 0) + +/* * cgroup_mutex is the master lock. Any modification to cgroup or its * hierarchy must be performed while holding it. * @@ -248,7 +256,7 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css, */ bool cgroup_ssid_enabled(int ssid) { - if (CGROUP_SUBSYS_COUNT == 0) + if (!CGROUP_HAS_SUBSYS_CONFIG) return false; return static_key_enabled(cgroup_subsys_enabled_key[ssid]); @@ -472,7 +480,7 @@ static u16 cgroup_ss_mask(struct cgroup *cgrp) static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp, struct cgroup_subsys *ss) { - if (ss) + if (CGROUP_HAS_SUBSYS_CONFIG && ss) return rcu_dereference_check(cgrp->subsys[ss->id], lockdep_is_held(&cgroup_mutex)); else @@ -550,6 +558,9 @@ struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgrp, { struct cgroup_subsys_state *css; + if (!CGROUP_HAS_SUBSYS_CONFIG) + return NULL; + do { css = cgroup_css(cgrp, ss); @@ -577,6 +588,9 @@ struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgrp, { struct cgroup_subsys_state *css; + if (!CGROUP_HAS_SUBSYS_CONFIG) + return NULL; + rcu_read_lock(); do { @@ -647,7 +661,7 @@ struct cgroup_subsys_state *of_css(struct kernfs_open_file *of) * the matching css from the cgroup's subsys table is guaranteed to * be and stay valid until the enclosing operation is complete. */ - if (cft->ss) + if (CGROUP_HAS_SUBSYS_CONFIG && cft->ss) return rcu_dereference_raw(cgrp->subsys[cft->ss->id]); else return &cgrp->self; @@ -695,7 +709,7 @@ EXPORT_SYMBOL_GPL(of_css); */ #define do_each_subsys_mask(ss, ssid, ss_mask) do { \ unsigned long __ss_mask = (ss_mask); \ - if (!CGROUP_SUBSYS_COUNT) { /* to avoid spurious gcc warning */ \ + if (!CGROUP_HAS_SUBSYS_CONFIG) { \ (ssid) = 0; \ break; \ } \ @@ -2169,13 +2183,14 @@ static void cgroup_kill_sb(struct super_block *sb) /* * If @root doesn't have any children, start killing it. * This prevents new mounts by disabling percpu_ref_tryget_live(). - * cgroup_mount() may wait for @root's release. * * And don't kill the default root. */ if (list_empty(&root->cgrp.self.children) && root != &cgrp_dfl_root && - !percpu_ref_is_dying(&root->cgrp.self.refcnt)) + !percpu_ref_is_dying(&root->cgrp.self.refcnt)) { + cgroup_bpf_offline(&root->cgrp); percpu_ref_kill(&root->cgrp.self.refcnt); + } cgroup_put(&root->cgrp); kernfs_kill_sb(sb); } @@ -2373,7 +2388,7 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, struct css_set *cset = tset->cur_cset; struct task_struct *task = tset->cur_task; - while (&cset->mg_node != tset->csets) { + while (CGROUP_HAS_SUBSYS_CONFIG && &cset->mg_node != tset->csets) { if (!task) task = list_first_entry(&cset->mg_tasks, struct task_struct, cg_list); @@ -4644,7 +4659,7 @@ void css_task_iter_start(struct cgroup_subsys_state *css, unsigned int flags, it->ss = css->ss; it->flags = flags; - if (it->ss) + if (CGROUP_HAS_SUBSYS_CONFIG && it->ss) it->cset_pos = &css->cgroup->e_csets[css->ss->id]; else it->cset_pos = &css->cgroup->cset_links; @@ -6559,74 +6574,51 @@ int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v) */ #ifdef CONFIG_SOCK_CGROUP_DATA -#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID) - -DEFINE_SPINLOCK(cgroup_sk_update_lock); -static bool cgroup_sk_alloc_disabled __read_mostly; - -void cgroup_sk_alloc_disable(void) -{ - if (cgroup_sk_alloc_disabled) - return; - pr_info("cgroup: disabling cgroup2 socket matching due to net_prio or net_cls activation\n"); - cgroup_sk_alloc_disabled = true; -} - -#else - -#define cgroup_sk_alloc_disabled false - -#endif - void cgroup_sk_alloc(struct sock_cgroup_data *skcd) { - if (cgroup_sk_alloc_disabled) { - skcd->no_refcnt = 1; - return; - } - - /* Don't associate the sock with unrelated interrupted task's cgroup. */ - if (in_interrupt()) - return; + struct cgroup *cgroup; rcu_read_lock(); + /* Don't associate the sock with unrelated interrupted task's cgroup. */ + if (in_interrupt()) { + cgroup = &cgrp_dfl_root.cgrp; + cgroup_get(cgroup); + goto out; + } while (true) { struct css_set *cset; cset = task_css_set(current); if (likely(cgroup_tryget(cset->dfl_cgrp))) { - skcd->val = (unsigned long)cset->dfl_cgrp; - cgroup_bpf_get(cset->dfl_cgrp); + cgroup = cset->dfl_cgrp; break; } cpu_relax(); } - +out: + skcd->cgroup = cgroup; + cgroup_bpf_get(cgroup); rcu_read_unlock(); } void cgroup_sk_clone(struct sock_cgroup_data *skcd) { - if (skcd->val) { - if (skcd->no_refcnt) - return; - /* - * We might be cloning a socket which is left in an empty - * cgroup and the cgroup might have already been rmdir'd. - * Don't use cgroup_get_live(). - */ - cgroup_get(sock_cgroup_ptr(skcd)); - cgroup_bpf_get(sock_cgroup_ptr(skcd)); - } + struct cgroup *cgrp = sock_cgroup_ptr(skcd); + + /* + * We might be cloning a socket which is left in an empty + * cgroup and the cgroup might have already been rmdir'd. + * Don't use cgroup_get_live(). + */ + cgroup_get(cgrp); + cgroup_bpf_get(cgrp); } void cgroup_sk_free(struct sock_cgroup_data *skcd) { struct cgroup *cgrp = sock_cgroup_ptr(skcd); - if (skcd->no_refcnt) - return; cgroup_bpf_put(cgrp); cgroup_put(cgrp); } diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index adb5190c4429..2a9695ccb65f 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -160,6 +160,9 @@ struct cpuset { */ int use_parent_ecpus; int child_ecpus_count; + + /* Handle for cpuset.cpus.partition */ + struct cgroup_file partition_file; }; /* @@ -263,6 +266,16 @@ static inline int is_partition_root(const struct cpuset *cs) return cs->partition_root_state > 0; } +/* + * Send notification event of whenever partition_root_state changes. + */ +static inline void notify_partition_change(struct cpuset *cs, + int old_prs, int new_prs) +{ + if (old_prs != new_prs) + cgroup_file_notify(&cs->partition_file); +} + static struct cpuset top_cpuset = { .flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)), @@ -298,17 +311,19 @@ static struct cpuset top_cpuset = { if (is_cpuset_online(((des_cs) = css_cs((pos_css))))) /* - * There are two global locks guarding cpuset structures - cpuset_mutex and + * There are two global locks guarding cpuset structures - cpuset_rwsem and * callback_lock. We also require taking task_lock() when dereferencing a * task's cpuset pointer. See "The task_lock() exception", at the end of this - * comment. + * comment. The cpuset code uses only cpuset_rwsem write lock. Other + * kernel subsystems can use cpuset_read_lock()/cpuset_read_unlock() to + * prevent change to cpuset structures. * * A task must hold both locks to modify cpusets. If a task holds - * cpuset_mutex, then it blocks others wanting that mutex, ensuring that it + * cpuset_rwsem, it blocks others wanting that rwsem, ensuring that it * is the only task able to also acquire callback_lock and be able to * modify cpusets. It can perform various checks on the cpuset structure * first, knowing nothing will change. It can also allocate memory while - * just holding cpuset_mutex. While it is performing these checks, various + * just holding cpuset_rwsem. While it is performing these checks, various * callback routines can briefly acquire callback_lock to query cpusets. * Once it is ready to make the changes, it takes callback_lock, blocking * everyone else. @@ -372,18 +387,29 @@ static inline bool is_in_v2_mode(void) } /* - * Return in pmask the portion of a cpusets's cpus_allowed that - * are online. If none are online, walk up the cpuset hierarchy - * until we find one that does have some online cpus. + * Return in pmask the portion of a task's cpusets's cpus_allowed that + * are online and are capable of running the task. If none are found, + * walk up the cpuset hierarchy until we find one that does have some + * appropriate cpus. * * One way or another, we guarantee to return some non-empty subset * of cpu_online_mask. * - * Call with callback_lock or cpuset_mutex held. + * Call with callback_lock or cpuset_rwsem held. */ -static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask) +static void guarantee_online_cpus(struct task_struct *tsk, + struct cpumask *pmask) { - while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) { + const struct cpumask *possible_mask = task_cpu_possible_mask(tsk); + struct cpuset *cs; + + if (WARN_ON(!cpumask_and(pmask, possible_mask, cpu_online_mask))) + cpumask_copy(pmask, cpu_online_mask); + + rcu_read_lock(); + cs = task_cs(tsk); + + while (!cpumask_intersects(cs->effective_cpus, pmask)) { cs = parent_cs(cs); if (unlikely(!cs)) { /* @@ -393,11 +419,13 @@ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask) * cpuset's effective_cpus is on its way to be * identical to cpu_online_mask. */ - cpumask_copy(pmask, cpu_online_mask); - return; + goto out_unlock; } } - cpumask_and(pmask, cs->effective_cpus, cpu_online_mask); + cpumask_and(pmask, pmask, cs->effective_cpus); + +out_unlock: + rcu_read_unlock(); } /* @@ -409,7 +437,7 @@ static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask) * One way or another, we guarantee to return some non-empty subset * of node_states[N_MEMORY]. * - * Call with callback_lock or cpuset_mutex held. + * Call with callback_lock or cpuset_rwsem held. */ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask) { @@ -421,7 +449,7 @@ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask) /* * update task's spread flag if cpuset's page/slab spread flag is set * - * Call with callback_lock or cpuset_mutex held. + * Call with callback_lock or cpuset_rwsem held. */ static void cpuset_update_task_spread_flag(struct cpuset *cs, struct task_struct *tsk) @@ -442,7 +470,7 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs, * * One cpuset is a subset of another if all its allowed CPUs and * Memory Nodes are a subset of the other, and its exclusive flags - * are only set if the other's are set. Call holding cpuset_mutex. + * are only set if the other's are set. Call holding cpuset_rwsem. */ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) @@ -551,7 +579,7 @@ static inline void free_cpuset(struct cpuset *cs) * If we replaced the flag and mask values of the current cpuset * (cur) with those values in the trial cpuset (trial), would * our various subset and exclusive rules still be valid? Presumes - * cpuset_mutex held. + * cpuset_rwsem held. * * 'cur' is the address of an actual, in-use cpuset. Operations * such as list traversal that depend on the actual address of the @@ -674,7 +702,7 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr, rcu_read_unlock(); } -/* Must be called with cpuset_mutex held. */ +/* Must be called with cpuset_rwsem held. */ static inline int nr_cpusets(void) { /* jump label reference count + the top-level cpuset */ @@ -700,7 +728,7 @@ static inline int nr_cpusets(void) * domains when operating in the severe memory shortage situations * that could cause allocation failures below. * - * Must be called with cpuset_mutex held. + * Must be called with cpuset_rwsem held. * * The three key local variables below are: * cp - cpuset pointer, used (together with pos_css) to perform a @@ -979,7 +1007,7 @@ partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[], * 'cpus' is removed, then call this routine to rebuild the * scheduler's dynamic sched domains. * - * Call with cpuset_mutex held. Takes get_online_cpus(). + * Call with cpuset_rwsem held. Takes cpus_read_lock(). */ static void rebuild_sched_domains_locked(void) { @@ -1040,11 +1068,11 @@ static void rebuild_sched_domains_locked(void) void rebuild_sched_domains(void) { - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); rebuild_sched_domains_locked(); percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); } /** @@ -1052,7 +1080,7 @@ void rebuild_sched_domains(void) * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed * * Iterate through each task of @cs updating its cpus_allowed to the - * effective cpuset's. As this function is called with cpuset_mutex held, + * effective cpuset's. As this function is called with cpuset_rwsem held, * cpuset membership stays stable. */ static void update_tasks_cpumask(struct cpuset *cs) @@ -1114,7 +1142,7 @@ enum subparts_cmd { * cpus_allowed can be granted or an error code will be returned. * * For partcmd_disable, the cpuset is being transofrmed from a partition - * root back to a non-partition root. any CPUs in cpus_allowed that are in + * root back to a non-partition root. Any CPUs in cpus_allowed that are in * parent's subparts_cpus will be taken away from that cpumask and put back * into parent's effective_cpus. 0 should always be returned. * @@ -1148,6 +1176,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, struct cpuset *parent = parent_cs(cpuset); int adding; /* Moving cpus from effective_cpus to subparts_cpus */ int deleting; /* Moving cpus from subparts_cpus to effective_cpus */ + int old_prs, new_prs; bool part_error = false; /* Partition error? */ percpu_rwsem_assert_held(&cpuset_rwsem); @@ -1183,6 +1212,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, * A cpumask update cannot make parent's effective_cpus become empty. */ adding = deleting = false; + old_prs = new_prs = cpuset->partition_root_state; if (cmd == partcmd_enable) { cpumask_copy(tmp->addmask, cpuset->cpus_allowed); adding = true; @@ -1225,7 +1255,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, /* * partcmd_update w/o newmask: * - * addmask = cpus_allowed & parent->effectiveb_cpus + * addmask = cpus_allowed & parent->effective_cpus * * Note that parent's subparts_cpus may have been * pre-shrunk in case there is a change in the cpu list. @@ -1247,11 +1277,11 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, switch (cpuset->partition_root_state) { case PRS_ENABLED: if (part_error) - cpuset->partition_root_state = PRS_ERROR; + new_prs = PRS_ERROR; break; case PRS_ERROR: if (!part_error) - cpuset->partition_root_state = PRS_ENABLED; + new_prs = PRS_ENABLED; break; } /* @@ -1260,10 +1290,10 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, part_error = (prev_prs == PRS_ERROR); } - if (!part_error && (cpuset->partition_root_state == PRS_ERROR)) + if (!part_error && (new_prs == PRS_ERROR)) return 0; /* Nothing need to be done */ - if (cpuset->partition_root_state == PRS_ERROR) { + if (new_prs == PRS_ERROR) { /* * Remove all its cpus from parent's subparts_cpus. */ @@ -1272,7 +1302,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, parent->subparts_cpus); } - if (!adding && !deleting) + if (!adding && !deleting && (new_prs == old_prs)) return 0; /* @@ -1299,7 +1329,12 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, } parent->nr_subparts_cpus = cpumask_weight(parent->subparts_cpus); + + if (old_prs != new_prs) + cpuset->partition_root_state = new_prs; + spin_unlock_irq(&callback_lock); + notify_partition_change(cpuset, old_prs, new_prs); return cmd == partcmd_update; } @@ -1314,13 +1349,14 @@ static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd, * * On legacy hierarchy, effective_cpus will be the same with cpu_allowed. * - * Called with cpuset_mutex held + * Called with cpuset_rwsem held */ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) { struct cpuset *cp; struct cgroup_subsys_state *pos_css; bool need_rebuild_sched_domains = false; + int old_prs, new_prs; rcu_read_lock(); cpuset_for_each_descendant_pre(cp, pos_css, cs) { @@ -1360,17 +1396,18 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) * update_tasks_cpumask() again for tasks in the parent * cpuset if the parent's subparts_cpus changes. */ - if ((cp != cs) && cp->partition_root_state) { + old_prs = new_prs = cp->partition_root_state; + if ((cp != cs) && old_prs) { switch (parent->partition_root_state) { case PRS_DISABLED: /* * If parent is not a partition root or an - * invalid partition root, clear the state - * state and the CS_CPU_EXCLUSIVE flag. + * invalid partition root, clear its state + * and its CS_CPU_EXCLUSIVE flag. */ WARN_ON_ONCE(cp->partition_root_state != PRS_ERROR); - cp->partition_root_state = 0; + new_prs = PRS_DISABLED; /* * clear_bit() is an atomic operation and @@ -1391,11 +1428,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) /* * When parent is invalid, it has to be too. */ - cp->partition_root_state = PRS_ERROR; - if (cp->nr_subparts_cpus) { - cp->nr_subparts_cpus = 0; - cpumask_clear(cp->subparts_cpus); - } + new_prs = PRS_ERROR; break; } } @@ -1407,8 +1440,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) spin_lock_irq(&callback_lock); cpumask_copy(cp->effective_cpus, tmp->new_cpus); - if (cp->nr_subparts_cpus && - (cp->partition_root_state != PRS_ENABLED)) { + if (cp->nr_subparts_cpus && (new_prs != PRS_ENABLED)) { cp->nr_subparts_cpus = 0; cpumask_clear(cp->subparts_cpus); } else if (cp->nr_subparts_cpus) { @@ -1435,7 +1467,12 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp) = cpumask_weight(cp->subparts_cpus); } } + + if (new_prs != old_prs) + cp->partition_root_state = new_prs; + spin_unlock_irq(&callback_lock); + notify_partition_change(cp, old_prs, new_prs); WARN_ON(!is_in_v2_mode() && !cpumask_equal(cp->cpus_allowed, cp->effective_cpus)); @@ -1612,6 +1649,11 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, { struct cpuset_migrate_mm_work *mwork; + if (nodes_equal(*from, *to)) { + mmput(mm); + return; + } + mwork = kzalloc(sizeof(*mwork), GFP_KERNEL); if (mwork) { mwork->mm = mm; @@ -1664,12 +1706,12 @@ static void *cpuset_being_rebound; * @cs: the cpuset in which each task's mems_allowed mask needs to be changed * * Iterate through each task of @cs updating its mems_allowed to the - * effective cpuset's. As this function is called with cpuset_mutex held, + * effective cpuset's. As this function is called with cpuset_rwsem held, * cpuset membership stays stable. */ static void update_tasks_nodemask(struct cpuset *cs) { - static nodemask_t newmems; /* protected by cpuset_mutex */ + static nodemask_t newmems; /* protected by cpuset_rwsem */ struct css_task_iter it; struct task_struct *task; @@ -1682,7 +1724,7 @@ static void update_tasks_nodemask(struct cpuset *cs) * take while holding tasklist_lock. Forks can happen - the * mpol_dup() cpuset_being_rebound check will catch such forks, * and rebind their vma mempolicies too. Because we still hold - * the global cpuset_mutex, we know that no other rebind effort + * the global cpuset_rwsem, we know that no other rebind effort * will be contending for the global variable cpuset_being_rebound. * It's ok if we rebind the same mm twice; mpol_rebind_mm() * is idempotent. Also migrate pages in each mm to new nodes. @@ -1728,7 +1770,7 @@ static void update_tasks_nodemask(struct cpuset *cs) * * On legacy hierarchy, effective_mems will be the same with mems_allowed. * - * Called with cpuset_mutex held + * Called with cpuset_rwsem held */ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems) { @@ -1781,7 +1823,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems) * mempolicies and if the cpuset is marked 'memory_migrate', * migrate the tasks pages to the new memory. * - * Call with cpuset_mutex held. May take callback_lock during call. + * Call with cpuset_rwsem held. May take callback_lock during call. * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, * lock each such tasks mm->mmap_lock, scan its vma's and rebind * their mempolicies to the cpusets new mems_allowed. @@ -1871,7 +1913,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) * @cs: the cpuset in which each task's spread flags needs to be changed * * Iterate through each task of @cs updating its spread flags. As this - * function is called with cpuset_mutex held, cpuset membership stays + * function is called with cpuset_rwsem held, cpuset membership stays * stable. */ static void update_tasks_flags(struct cpuset *cs) @@ -1891,7 +1933,7 @@ static void update_tasks_flags(struct cpuset *cs) * cs: the cpuset to update * turning_on: whether the flag is being set or cleared * - * Call with cpuset_mutex held. + * Call with cpuset_rwsem held. */ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, @@ -1937,34 +1979,32 @@ out: /* * update_prstate - update partititon_root_state - * cs: the cpuset to update - * val: 0 - disabled, 1 - enabled + * cs: the cpuset to update + * new_prs: new partition root state * - * Call with cpuset_mutex held. + * Call with cpuset_rwsem held. */ -static int update_prstate(struct cpuset *cs, int val) +static int update_prstate(struct cpuset *cs, int new_prs) { - int err; + int err, old_prs = cs->partition_root_state; struct cpuset *parent = parent_cs(cs); - struct tmpmasks tmp; + struct tmpmasks tmpmask; - if ((val != 0) && (val != 1)) - return -EINVAL; - if (val == cs->partition_root_state) + if (old_prs == new_prs) return 0; /* * Cannot force a partial or invalid partition root to a full * partition root. */ - if (val && cs->partition_root_state) + if (new_prs && (old_prs == PRS_ERROR)) return -EINVAL; - if (alloc_cpumasks(NULL, &tmp)) + if (alloc_cpumasks(NULL, &tmpmask)) return -ENOMEM; err = -EINVAL; - if (!cs->partition_root_state) { + if (!old_prs) { /* * Turning on partition root requires setting the * CS_CPU_EXCLUSIVE bit implicitly as well and cpus_allowed @@ -1978,31 +2018,27 @@ static int update_prstate(struct cpuset *cs, int val) goto out; err = update_parent_subparts_cpumask(cs, partcmd_enable, - NULL, &tmp); + NULL, &tmpmask); if (err) { update_flag(CS_CPU_EXCLUSIVE, cs, 0); goto out; } - cs->partition_root_state = PRS_ENABLED; } else { /* * Turning off partition root will clear the * CS_CPU_EXCLUSIVE bit. */ - if (cs->partition_root_state == PRS_ERROR) { - cs->partition_root_state = 0; + if (old_prs == PRS_ERROR) { update_flag(CS_CPU_EXCLUSIVE, cs, 0); err = 0; goto out; } err = update_parent_subparts_cpumask(cs, partcmd_disable, - NULL, &tmp); + NULL, &tmpmask); if (err) goto out; - cs->partition_root_state = 0; - /* Turning off CS_CPU_EXCLUSIVE will not return error */ update_flag(CS_CPU_EXCLUSIVE, cs, 0); } @@ -2015,11 +2051,18 @@ static int update_prstate(struct cpuset *cs, int val) update_tasks_cpumask(parent); if (parent->child_ecpus_count) - update_sibling_cpumasks(parent, cs, &tmp); + update_sibling_cpumasks(parent, cs, &tmpmask); rebuild_sched_domains_locked(); out: - free_cpumasks(NULL, &tmp); + if (!err) { + spin_lock_irq(&callback_lock); + cs->partition_root_state = new_prs; + spin_unlock_irq(&callback_lock); + notify_partition_change(cs, old_prs, new_prs); + } + + free_cpumasks(NULL, &tmpmask); return err; } @@ -2126,7 +2169,7 @@ static int fmeter_getrate(struct fmeter *fmp) static struct cpuset *cpuset_attach_old_cs; -/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */ +/* Called by cgroups to determine if a cpuset is usable; cpuset_rwsem held */ static int cpuset_can_attach(struct cgroup_taskset *tset) { struct cgroup_subsys_state *css; @@ -2178,7 +2221,7 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset) } /* - * Protected by cpuset_mutex. cpus_attach is used only by cpuset_attach() + * Protected by cpuset_rwsem. cpus_attach is used only by cpuset_attach() * but we can't allocate it dynamically there. Define it global and * allocate from cpuset_init(). */ @@ -2186,7 +2229,7 @@ static cpumask_var_t cpus_attach; static void cpuset_attach(struct cgroup_taskset *tset) { - /* static buf protected by cpuset_mutex */ + /* static buf protected by cpuset_rwsem */ static nodemask_t cpuset_attach_nodemask_to; struct task_struct *task; struct task_struct *leader; @@ -2199,15 +2242,13 @@ static void cpuset_attach(struct cgroup_taskset *tset) percpu_down_write(&cpuset_rwsem); - /* prepare for attach */ - if (cs == &top_cpuset) - cpumask_copy(cpus_attach, cpu_possible_mask); - else - guarantee_online_cpus(cs, cpus_attach); - guarantee_online_mems(cs, &cpuset_attach_nodemask_to); cgroup_taskset_for_each(task, css, tset) { + if (cs != &top_cpuset) + guarantee_online_cpus(task, cpus_attach); + else + cpumask_copy(cpus_attach, task_cpu_possible_mask(task)); /* * can_attach beforehand should guarantee that this doesn't * fail. TODO: have a better way to handle failure here @@ -2282,7 +2323,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, cpuset_filetype_t type = cft->private; int retval = 0; - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) { retval = -ENODEV; @@ -2320,7 +2361,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, } out_unlock: percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); return retval; } @@ -2331,7 +2372,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, cpuset_filetype_t type = cft->private; int retval = -ENODEV; - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) goto out_unlock; @@ -2346,7 +2387,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, } out_unlock: percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); return retval; } @@ -2378,14 +2419,14 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, * operation like this one can lead to a deadlock through kernfs * active_ref protection. Let's break the protection. Losing the * protection is okay as we check whether @cs is online after - * grabbing cpuset_mutex anyway. This only happens on the legacy + * grabbing cpuset_rwsem anyway. This only happens on the legacy * hierarchies. */ css_get(&cs->css); kernfs_break_active_protection(of->kn); flush_work(&cpuset_hotplug_work); - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) goto out_unlock; @@ -2411,7 +2452,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, free_cpuset(trialcs); out_unlock: percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); kernfs_unbreak_active_protection(of->kn); css_put(&cs->css); flush_workqueue(cpuset_migrate_mm_wq); @@ -2542,7 +2583,7 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf, return -EINVAL; css_get(&cs->css); - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); if (!is_cpuset_online(cs)) goto out_unlock; @@ -2550,7 +2591,7 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf, retval = update_prstate(cs, val); out_unlock: percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); css_put(&cs->css); return retval ?: nbytes; } @@ -2702,6 +2743,7 @@ static struct cftype dfl_files[] = { .write = sched_partition_write, .private = FILE_PARTITION_ROOT, .flags = CFTYPE_NOT_ON_ROOT, + .file_offset = offsetof(struct cpuset, partition_file), }, { @@ -2737,12 +2779,16 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css) return ERR_PTR(-ENOMEM); } - set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); + __set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); nodes_clear(cs->mems_allowed); nodes_clear(cs->effective_mems); fmeter_init(&cs->fmeter); cs->relax_domain_level = -1; + /* Set CS_MEMORY_MIGRATE for default hierarchy */ + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) + __set_bit(CS_MEMORY_MIGRATE, &cs->flags); + return &cs->css; } @@ -2756,7 +2802,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) if (!parent) return 0; - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); set_bit(CS_ONLINE, &cs->flags); @@ -2809,7 +2855,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) spin_unlock_irq(&callback_lock); out_unlock: percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); return 0; } @@ -2828,7 +2874,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css) { struct cpuset *cs = css_cs(css); - get_online_cpus(); + cpus_read_lock(); percpu_down_write(&cpuset_rwsem); if (is_partition_root(cs)) @@ -2849,7 +2895,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css) clear_bit(CS_ONLINE, &cs->flags); percpu_up_write(&cpuset_rwsem); - put_online_cpus(); + cpus_read_unlock(); } static void cpuset_css_free(struct cgroup_subsys_state *css) @@ -3060,7 +3106,7 @@ retry: goto retry; } - parent = parent_cs(cs); + parent = parent_cs(cs); compute_effective_cpumask(&new_cpus, cs, parent); nodes_and(new_mems, cs->mems_allowed, parent->effective_mems); @@ -3082,8 +3128,10 @@ retry: if (is_partition_root(cs) && (cpumask_empty(&new_cpus) || (parent->partition_root_state == PRS_ERROR))) { if (cs->nr_subparts_cpus) { + spin_lock_irq(&callback_lock); cs->nr_subparts_cpus = 0; cpumask_clear(cs->subparts_cpus); + spin_unlock_irq(&callback_lock); compute_effective_cpumask(&new_cpus, cs, parent); } @@ -3095,9 +3143,17 @@ retry: */ if ((parent->partition_root_state == PRS_ERROR) || cpumask_empty(&new_cpus)) { + int old_prs; + update_parent_subparts_cpumask(cs, partcmd_disable, NULL, tmp); - cs->partition_root_state = PRS_ERROR; + old_prs = cs->partition_root_state; + if (old_prs != PRS_ERROR) { + spin_lock_irq(&callback_lock); + cs->partition_root_state = PRS_ERROR; + spin_unlock_irq(&callback_lock); + notify_partition_change(cs, old_prs, PRS_ERROR); + } } cpuset_force_rebuild(); } @@ -3168,6 +3224,13 @@ static void cpuset_hotplug_workfn(struct work_struct *work) cpus_updated = !cpumask_equal(top_cpuset.effective_cpus, &new_cpus); mems_updated = !nodes_equal(top_cpuset.effective_mems, new_mems); + /* + * In the rare case that hotplug removes all the cpus in subparts_cpus, + * we assumed that cpus are updated. + */ + if (!cpus_updated && top_cpuset.nr_subparts_cpus) + cpus_updated = true; + /* synchronize cpus_allowed to cpu_active_mask */ if (cpus_updated) { spin_lock_irq(&callback_lock); @@ -3302,9 +3365,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) unsigned long flags; spin_lock_irqsave(&callback_lock, flags); - rcu_read_lock(); - guarantee_online_cpus(task_cs(tsk), pmask); - rcu_read_unlock(); + guarantee_online_cpus(tsk, pmask); spin_unlock_irqrestore(&callback_lock, flags); } @@ -3318,13 +3379,22 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) * which will not contain a sane cpumask during cases such as cpu hotplugging. * This is the absolute last resort for the scheduler and it is only used if * _every_ other avenue has been traveled. + * + * Returns true if the affinity of @tsk was changed, false otherwise. **/ -void cpuset_cpus_allowed_fallback(struct task_struct *tsk) +bool cpuset_cpus_allowed_fallback(struct task_struct *tsk) { + const struct cpumask *possible_mask = task_cpu_possible_mask(tsk); + const struct cpumask *cs_mask; + bool changed = false; + rcu_read_lock(); - do_set_cpus_allowed(tsk, is_in_v2_mode() ? - task_cs(tsk)->cpus_allowed : cpu_possible_mask); + cs_mask = task_cs(tsk)->cpus_allowed; + if (is_in_v2_mode() && cpumask_subset(cs_mask, possible_mask)) { + do_set_cpus_allowed(tsk, cs_mask); + changed = true; + } rcu_read_unlock(); /* @@ -3344,6 +3414,7 @@ void cpuset_cpus_allowed_fallback(struct task_struct *tsk) * select_fallback_rq() will fix things ups and set cpu_possible_mask * if required. */ + return changed; } void __init cpuset_init_current_mems_allowed(void) @@ -3603,7 +3674,7 @@ void __cpuset_memory_pressure_bump(void) * - Used for /proc/<pid>/cpuset. * - No need to task_lock(tsk) on this tsk->cpuset reference, as it * doesn't really matter if tsk->cpuset changes after we read it, - * and we take cpuset_mutex, keeping cpuset_attach() from changing it + * and we take cpuset_rwsem, keeping cpuset_attach() from changing it * anyway. */ int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns, diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c index f5e8828c109c..0d5c29879a50 100644 --- a/kernel/cgroup/namespace.c +++ b/kernel/cgroup/namespace.c @@ -24,7 +24,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void) struct cgroup_namespace *new_ns; int ret; - new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL); + new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL_ACCOUNT); if (!new_ns) return ERR_PTR(-ENOMEM); ret = ns_alloc_inum(&new_ns->ns); diff --git a/kernel/compat.c b/kernel/compat.c index 05adfd6fa8bf..55551989d9da 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -269,24 +269,3 @@ get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) return 0; } EXPORT_SYMBOL_GPL(get_compat_sigset); - -/* - * Allocate user-space memory for the duration of a single system call, - * in order to marshall parameters inside a compat thunk. - */ -void __user *compat_alloc_user_space(unsigned long len) -{ - void __user *ptr; - - /* If len would occupy more than half of the entire compat space... */ - if (unlikely(len > (((compat_uptr_t)~0) >> 1))) - return NULL; - - ptr = arch_compat_alloc_user_space(len); - - if (unlikely(!access_ok(ptr, len))) - return NULL; - - return ptr; -} -EXPORT_SYMBOL_GPL(compat_alloc_user_space); diff --git a/kernel/cpu.c b/kernel/cpu.c index 804b847912dc..192e43a87407 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -41,14 +41,19 @@ #include "smpboot.h" /** - * cpuhp_cpu_state - Per cpu hotplug state storage + * struct cpuhp_cpu_state - Per cpu hotplug state storage * @state: The current cpu state * @target: The target state + * @fail: Current CPU hotplug callback state * @thread: Pointer to the hotplug thread * @should_run: Thread should execute * @rollback: Perform a rollback * @single: Single callback invocation * @bringup: Single callback bringup or teardown selector + * @cpu: CPU number + * @node: Remote CPU node; for multi-instance, do a + * single entry callback for install/remove + * @last: For multi-instance rollback, remember how far we got * @cb_state: The state for a single callback (install/uninstall) * @result: Result of the operation * @done_up: Signal completion to the issuer of the task for cpu-up @@ -106,11 +111,12 @@ static inline void cpuhp_lock_release(bool bringup) { } #endif /** - * cpuhp_step - Hotplug state machine step + * struct cpuhp_step - Hotplug state machine step * @name: Name of the step * @startup: Startup function of the step * @teardown: Teardown function of the step * @cant_stop: Bringup/teardown can't be stopped at this step + * @multi_instance: State has multiple instances which get added afterwards */ struct cpuhp_step { const char *name; @@ -124,7 +130,9 @@ struct cpuhp_step { int (*multi)(unsigned int cpu, struct hlist_node *node); } teardown; + /* private: */ struct hlist_head list; + /* public: */ bool cant_stop; bool multi_instance; }; @@ -143,7 +151,7 @@ static bool cpuhp_step_empty(bool bringup, struct cpuhp_step *step) } /** - * cpuhp_invoke_callback _ Invoke the callbacks for a given state + * cpuhp_invoke_callback - Invoke the callbacks for a given state * @cpu: The cpu for which the callback should be invoked * @state: The state to do callbacks for * @bringup: True if the bringup callback should be invoked @@ -151,6 +159,8 @@ static bool cpuhp_step_empty(bool bringup, struct cpuhp_step *step) * @lastp: For multi-instance rollback, remember how far we got * * Called from cpu hotplug and from the state register machinery. + * + * Return: %0 on success or a negative errno code */ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, bool bringup, struct hlist_node *node, @@ -682,6 +692,10 @@ static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, ret = cpuhp_invoke_callback_range(true, cpu, st, target); if (ret) { + pr_debug("CPU UP failed (%d) CPU %u state %s (%d)\n", + ret, cpu, cpuhp_get_step(st->state)->name, + st->state); + cpuhp_reset_state(st, prev_state); if (can_rollback_cpu(st)) WARN_ON(cpuhp_invoke_callback_range(false, cpu, st, @@ -1081,6 +1095,9 @@ static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, ret = cpuhp_invoke_callback_range(false, cpu, st, target); if (ret) { + pr_debug("CPU DOWN failed (%d) CPU %u state %s (%d)\n", + ret, cpu, cpuhp_get_step(st->state)->name, + st->state); cpuhp_reset_state(st, prev_state); @@ -1183,6 +1200,8 @@ static int cpu_down(unsigned int cpu, enum cpuhp_state target) * This function is meant to be used by device core cpu subsystem only. * * Other subsystems should use remove_cpu() instead. + * + * Return: %0 on success or a negative errno code */ int cpu_device_down(struct device *dev) { @@ -1395,6 +1414,8 @@ out: * This function is meant to be used by device core cpu subsystem only. * * Other subsystems should use add_cpu() instead. + * + * Return: %0 on success or a negative errno code */ int cpu_device_up(struct device *dev) { @@ -1420,6 +1441,8 @@ EXPORT_SYMBOL_GPL(add_cpu); * On some architectures like arm64, we can hibernate on any CPU, but on * wake up the CPU we hibernated on might be offline as a side effect of * using maxcpus= for example. + * + * Return: %0 on success or a negative errno code */ int bringup_hibernate_cpu(unsigned int sleep_cpu) { @@ -1976,6 +1999,7 @@ EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); /** * __cpuhp_setup_state_cpuslocked - Setup the callbacks for an hotplug machine state * @state: The state to setup + * @name: Name of the step * @invoke: If true, the startup function is invoked for cpus where * cpu state >= @state * @startup: startup callback function @@ -1984,9 +2008,9 @@ EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); * added afterwards. * * The caller needs to hold cpus read locked while calling this function. - * Returns: + * Return: * On success: - * Positive state number if @state is CPUHP_AP_ONLINE_DYN + * Positive state number if @state is CPUHP_AP_ONLINE_DYN; * 0 for all other states * On failure: proper (negative) error code */ @@ -2232,18 +2256,17 @@ int cpuhp_smt_enable(void) #endif #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) -static ssize_t show_cpuhp_state(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t state_show(struct device *dev, + struct device_attribute *attr, char *buf) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); return sprintf(buf, "%d\n", st->state); } -static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); +static DEVICE_ATTR_RO(state); -static ssize_t write_cpuhp_target(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) +static ssize_t target_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); struct cpuhp_step *sp; @@ -2281,19 +2304,17 @@ out: return ret ? ret : count; } -static ssize_t show_cpuhp_target(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t target_show(struct device *dev, + struct device_attribute *attr, char *buf) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); return sprintf(buf, "%d\n", st->target); } -static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); - +static DEVICE_ATTR_RW(target); -static ssize_t write_cpuhp_fail(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) +static ssize_t fail_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); struct cpuhp_step *sp; @@ -2342,15 +2363,15 @@ static ssize_t write_cpuhp_fail(struct device *dev, return count; } -static ssize_t show_cpuhp_fail(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t fail_show(struct device *dev, + struct device_attribute *attr, char *buf) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); return sprintf(buf, "%d\n", st->fail); } -static DEVICE_ATTR(fail, 0644, show_cpuhp_fail, write_cpuhp_fail); +static DEVICE_ATTR_RW(fail); static struct attribute *cpuhp_cpu_attrs[] = { &dev_attr_state.attr, @@ -2365,7 +2386,7 @@ static const struct attribute_group cpuhp_cpu_attr_group = { NULL }; -static ssize_t show_cpuhp_states(struct device *dev, +static ssize_t states_show(struct device *dev, struct device_attribute *attr, char *buf) { ssize_t cur, res = 0; @@ -2384,7 +2405,7 @@ static ssize_t show_cpuhp_states(struct device *dev, mutex_unlock(&cpuhp_state_mutex); return res; } -static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); +static DEVICE_ATTR_RO(states); static struct attribute *cpuhp_cpu_root_attrs[] = { &dev_attr_states.attr, @@ -2457,28 +2478,27 @@ static const char *smt_states[] = { [CPU_SMT_NOT_IMPLEMENTED] = "notimplemented", }; -static ssize_t -show_smt_control(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t control_show(struct device *dev, + struct device_attribute *attr, char *buf) { const char *state = smt_states[cpu_smt_control]; return snprintf(buf, PAGE_SIZE - 2, "%s\n", state); } -static ssize_t -store_smt_control(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) +static ssize_t control_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { return __store_smt_control(dev, attr, buf, count); } -static DEVICE_ATTR(control, 0644, show_smt_control, store_smt_control); +static DEVICE_ATTR_RW(control); -static ssize_t -show_smt_active(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t active_show(struct device *dev, + struct device_attribute *attr, char *buf) { return snprintf(buf, PAGE_SIZE - 2, "%d\n", sched_smt_active()); } -static DEVICE_ATTR(active, 0444, show_smt_active, NULL); +static DEVICE_ATTR_RO(active); static struct attribute *cpuhp_smt_attrs[] = { &dev_attr_control.attr, diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c index f7e1d0eccdbc..246efc74e3f3 100644 --- a/kernel/cpu_pm.c +++ b/kernel/cpu_pm.c @@ -13,19 +13,32 @@ #include <linux/spinlock.h> #include <linux/syscore_ops.h> -static ATOMIC_NOTIFIER_HEAD(cpu_pm_notifier_chain); +/* + * atomic_notifiers use a spinlock_t, which can block under PREEMPT_RT. + * Notifications for cpu_pm will be issued by the idle task itself, which can + * never block, IOW it requires using a raw_spinlock_t. + */ +static struct { + struct raw_notifier_head chain; + raw_spinlock_t lock; +} cpu_pm_notifier = { + .chain = RAW_NOTIFIER_INIT(cpu_pm_notifier.chain), + .lock = __RAW_SPIN_LOCK_UNLOCKED(cpu_pm_notifier.lock), +}; static int cpu_pm_notify(enum cpu_pm_event event) { int ret; /* - * atomic_notifier_call_chain has a RCU read critical section, which - * could be disfunctional in cpu idle. Copy RCU_NONIDLE code to let - * RCU know this. + * This introduces a RCU read critical section, which could be + * disfunctional in cpu idle. Copy RCU_NONIDLE code to let RCU know + * this. */ rcu_irq_enter_irqson(); - ret = atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL); + rcu_read_lock(); + ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL); + rcu_read_unlock(); rcu_irq_exit_irqson(); return notifier_to_errno(ret); @@ -33,10 +46,13 @@ static int cpu_pm_notify(enum cpu_pm_event event) static int cpu_pm_notify_robust(enum cpu_pm_event event_up, enum cpu_pm_event event_down) { + unsigned long flags; int ret; rcu_irq_enter_irqson(); - ret = atomic_notifier_call_chain_robust(&cpu_pm_notifier_chain, event_up, event_down, NULL); + raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags); + ret = raw_notifier_call_chain_robust(&cpu_pm_notifier.chain, event_up, event_down, NULL); + raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags); rcu_irq_exit_irqson(); return notifier_to_errno(ret); @@ -49,12 +65,17 @@ static int cpu_pm_notify_robust(enum cpu_pm_event event_up, enum cpu_pm_event ev * Add a driver to a list of drivers that are notified about * CPU and CPU cluster low power entry and exit. * - * This function may sleep, and has the same return conditions as - * raw_notifier_chain_register. + * This function has the same return conditions as raw_notifier_chain_register. */ int cpu_pm_register_notifier(struct notifier_block *nb) { - return atomic_notifier_chain_register(&cpu_pm_notifier_chain, nb); + unsigned long flags; + int ret; + + raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags); + ret = raw_notifier_chain_register(&cpu_pm_notifier.chain, nb); + raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags); + return ret; } EXPORT_SYMBOL_GPL(cpu_pm_register_notifier); @@ -64,12 +85,17 @@ EXPORT_SYMBOL_GPL(cpu_pm_register_notifier); * * Remove a driver from the CPU PM notifier list. * - * This function may sleep, and has the same return conditions as - * raw_notifier_chain_unregister. + * This function has the same return conditions as raw_notifier_chain_unregister. */ int cpu_pm_unregister_notifier(struct notifier_block *nb) { - return atomic_notifier_chain_unregister(&cpu_pm_notifier_chain, nb); + unsigned long flags; + int ret; + + raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags); + ret = raw_notifier_chain_unregister(&cpu_pm_notifier.chain, nb); + raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags); + return ret; } EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier); diff --git a/kernel/cred.c b/kernel/cred.c index e6fd2b3fc31f..1ae0b4948a5a 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -225,8 +225,6 @@ struct cred *cred_alloc_blank(void) #ifdef CONFIG_DEBUG_CREDENTIALS new->magic = CRED_MAGIC; #endif - new->ucounts = get_ucounts(&init_ucounts); - if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0) goto error; @@ -286,13 +284,13 @@ struct cred *prepare_creds(void) new->security = NULL; #endif - if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0) - goto error; - new->ucounts = get_ucounts(new->ucounts); if (!new->ucounts) goto error; + if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0) + goto error; + validate_creds(new); return new; @@ -501,7 +499,7 @@ int commit_creds(struct cred *new) inc_rlimit_ucounts(new->ucounts, UCOUNT_RLIMIT_NPROC, 1); rcu_assign_pointer(task->real_cred, new); rcu_assign_pointer(task->cred, new); - if (new->user != old->user) + if (new->user != old->user || new->user_ns != old->user_ns) dec_rlimit_ucounts(old->ucounts, UCOUNT_RLIMIT_NPROC, 1); alter_cred_subscribers(old, -2); @@ -669,7 +667,7 @@ int set_cred_ucounts(struct cred *new) { struct task_struct *task = current; const struct cred *old = task->real_cred; - struct ucounts *old_ucounts = new->ucounts; + struct ucounts *new_ucounts, *old_ucounts = new->ucounts; if (new->user == old->user && new->user_ns == old->user_ns) return 0; @@ -681,9 +679,10 @@ int set_cred_ucounts(struct cred *new) if (old_ucounts && old_ucounts->ns == new->user_ns && uid_eq(old_ucounts->uid, new->euid)) return 0; - if (!(new->ucounts = alloc_ucounts(new->user_ns, new->euid))) + if (!(new_ucounts = alloc_ucounts(new->user_ns, new->euid))) return -EAGAIN; + new->ucounts = new_ucounts; if (old_ucounts) put_ucounts(old_ucounts); @@ -753,13 +752,13 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon) #ifdef CONFIG_SECURITY new->security = NULL; #endif - if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0) - goto error; - new->ucounts = get_ucounts(new->ucounts); if (!new->ucounts) goto error; + if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0) + goto error; + put_cred(old); validate_creds(new); return new; diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index b4aa6bb6b2bd..da06a5553835 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Kernel Debug Core * @@ -22,10 +23,6 @@ * * Original KGDB stub: David Grothe <dave@gcom.com>, * Tigran Aivazian <tigran@sco.com> - * - * This file is licensed under the terms of the GNU General Public License - * version 2. This program is licensed "as is" without any warranty of any - * kind, whether express or implied. */ #define pr_fmt(fmt) "KGDB: " fmt diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c index b6f28fad4307..9d34d2364b5a 100644 --- a/kernel/debug/gdbstub.c +++ b/kernel/debug/gdbstub.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Kernel Debug Core * @@ -22,10 +23,6 @@ * * Original KGDB stub: David Grothe <dave@gcom.com>, * Tigran Aivazian <tigran@sco.com> - * - * This file is licensed under the terms of the GNU General Public License - * version 2. This program is licensed "as is" without any warranty of any - * kind, whether express or implied. */ #include <linux/kernel.h> diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c index 2168f8dacb99..372025cf1ca3 100644 --- a/kernel/debug/kdb/kdb_bp.c +++ b/kernel/debug/kdb/kdb_bp.c @@ -523,51 +523,51 @@ static int kdb_ss(int argc, const char **argv) } static kdbtab_t bptab[] = { - { .cmd_name = "bp", - .cmd_func = kdb_bp, - .cmd_usage = "[<vaddr>]", - .cmd_help = "Set/Display breakpoints", - .cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, + { .name = "bp", + .func = kdb_bp, + .usage = "[<vaddr>]", + .help = "Set/Display breakpoints", + .flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "bl", - .cmd_func = kdb_bp, - .cmd_usage = "[<vaddr>]", - .cmd_help = "Display breakpoints", - .cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, + { .name = "bl", + .func = kdb_bp, + .usage = "[<vaddr>]", + .help = "Display breakpoints", + .flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "bc", - .cmd_func = kdb_bc, - .cmd_usage = "<bpnum>", - .cmd_help = "Clear Breakpoint", - .cmd_flags = KDB_ENABLE_FLOW_CTRL, + { .name = "bc", + .func = kdb_bc, + .usage = "<bpnum>", + .help = "Clear Breakpoint", + .flags = KDB_ENABLE_FLOW_CTRL, }, - { .cmd_name = "be", - .cmd_func = kdb_bc, - .cmd_usage = "<bpnum>", - .cmd_help = "Enable Breakpoint", - .cmd_flags = KDB_ENABLE_FLOW_CTRL, + { .name = "be", + .func = kdb_bc, + .usage = "<bpnum>", + .help = "Enable Breakpoint", + .flags = KDB_ENABLE_FLOW_CTRL, }, - { .cmd_name = "bd", - .cmd_func = kdb_bc, - .cmd_usage = "<bpnum>", - .cmd_help = "Disable Breakpoint", - .cmd_flags = KDB_ENABLE_FLOW_CTRL, + { .name = "bd", + .func = kdb_bc, + .usage = "<bpnum>", + .help = "Disable Breakpoint", + .flags = KDB_ENABLE_FLOW_CTRL, }, - { .cmd_name = "ss", - .cmd_func = kdb_ss, - .cmd_usage = "", - .cmd_help = "Single Step", - .cmd_minlen = 1, - .cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, + { .name = "ss", + .func = kdb_ss, + .usage = "", + .help = "Single Step", + .minlen = 1, + .flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, }, }; static kdbtab_t bphcmd = { - .cmd_name = "bph", - .cmd_func = kdb_bp, - .cmd_usage = "[<vaddr>]", - .cmd_help = "[datar [length]|dataw [length]] Set hw brk", - .cmd_flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, + .name = "bph", + .func = kdb_bp, + .usage = "[<vaddr>]", + .help = "[datar [length]|dataw [length]] Set hw brk", + .flags = KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS, }; /* Initialize the breakpoint table and register breakpoint commands. */ diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index 0220afda3200..e91fc3e4edd5 100644 --- a/kernel/debug/kdb/kdb_debugger.c +++ b/kernel/debug/kdb/kdb_debugger.c @@ -140,7 +140,6 @@ int kdb_stub(struct kgdb_state *ks) */ kdb_common_deinit_state(); KDB_STATE_CLEAR(PAGER); - kdbnearsym_cleanup(); if (error == KDB_CMD_KGDB) { if (KDB_STATE(DOING_KGDB)) KDB_STATE_CLEAR(DOING_KGDB); diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index d8ee5647b732..fa6deda894a1 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -33,7 +33,6 @@ #include <linux/kallsyms.h> #include <linux/kgdb.h> #include <linux/kdb.h> -#include <linux/list.h> #include <linux/notifier.h> #include <linux/interrupt.h> #include <linux/delay.h> @@ -654,16 +653,17 @@ static void kdb_cmderror(int diag) * Returns: * zero for success, a kdb diagnostic if error */ -struct defcmd_set { - int count; - bool usable; - char *name; - char *usage; - char *help; - char **command; +struct kdb_macro { + kdbtab_t cmd; /* Macro command */ + struct list_head statements; /* Associated statement list */ }; -static struct defcmd_set *defcmd_set; -static int defcmd_set_count; + +struct kdb_macro_statement { + char *statement; /* Statement text */ + struct list_head list_node; /* Statement list node */ +}; + +static struct kdb_macro *kdb_macro; static bool defcmd_in_progress; /* Forward references */ @@ -671,53 +671,55 @@ static int kdb_exec_defcmd(int argc, const char **argv); static int kdb_defcmd2(const char *cmdstr, const char *argv0) { - struct defcmd_set *s = defcmd_set + defcmd_set_count - 1; - char **save_command = s->command; + struct kdb_macro_statement *kms; + + if (!kdb_macro) + return KDB_NOTIMP; + if (strcmp(argv0, "endefcmd") == 0) { defcmd_in_progress = false; - if (!s->count) - s->usable = false; - if (s->usable) - /* macros are always safe because when executed each - * internal command re-enters kdb_parse() and is - * safety checked individually. - */ - kdb_register_flags(s->name, kdb_exec_defcmd, s->usage, - s->help, 0, - KDB_ENABLE_ALWAYS_SAFE); + if (!list_empty(&kdb_macro->statements)) + kdb_register(&kdb_macro->cmd); return 0; } - if (!s->usable) - return KDB_NOTIMP; - s->command = kcalloc(s->count + 1, sizeof(*(s->command)), GFP_KDB); - if (!s->command) { - kdb_printf("Could not allocate new kdb_defcmd table for %s\n", + + kms = kmalloc(sizeof(*kms), GFP_KDB); + if (!kms) { + kdb_printf("Could not allocate new kdb macro command: %s\n", cmdstr); - s->usable = false; return KDB_NOTIMP; } - memcpy(s->command, save_command, s->count * sizeof(*(s->command))); - s->command[s->count++] = kdb_strdup(cmdstr, GFP_KDB); - kfree(save_command); + + kms->statement = kdb_strdup(cmdstr, GFP_KDB); + list_add_tail(&kms->list_node, &kdb_macro->statements); + return 0; } static int kdb_defcmd(int argc, const char **argv) { - struct defcmd_set *save_defcmd_set = defcmd_set, *s; + kdbtab_t *mp; + if (defcmd_in_progress) { kdb_printf("kdb: nested defcmd detected, assuming missing " "endefcmd\n"); kdb_defcmd2("endefcmd", "endefcmd"); } if (argc == 0) { - int i; - for (s = defcmd_set; s < defcmd_set + defcmd_set_count; ++s) { - kdb_printf("defcmd %s \"%s\" \"%s\"\n", s->name, - s->usage, s->help); - for (i = 0; i < s->count; ++i) - kdb_printf("%s", s->command[i]); - kdb_printf("endefcmd\n"); + kdbtab_t *kp; + struct kdb_macro *kmp; + struct kdb_macro_statement *kms; + + list_for_each_entry(kp, &kdb_cmds_head, list_node) { + if (kp->func == kdb_exec_defcmd) { + kdb_printf("defcmd %s \"%s\" \"%s\"\n", + kp->name, kp->usage, kp->help); + kmp = container_of(kp, struct kdb_macro, cmd); + list_for_each_entry(kms, &kmp->statements, + list_node) + kdb_printf("%s", kms->statement); + kdb_printf("endefcmd\n"); + } } return 0; } @@ -727,45 +729,43 @@ static int kdb_defcmd(int argc, const char **argv) kdb_printf("Command only available during kdb_init()\n"); return KDB_NOTIMP; } - defcmd_set = kmalloc_array(defcmd_set_count + 1, sizeof(*defcmd_set), - GFP_KDB); - if (!defcmd_set) + kdb_macro = kzalloc(sizeof(*kdb_macro), GFP_KDB); + if (!kdb_macro) goto fail_defcmd; - memcpy(defcmd_set, save_defcmd_set, - defcmd_set_count * sizeof(*defcmd_set)); - s = defcmd_set + defcmd_set_count; - memset(s, 0, sizeof(*s)); - s->usable = true; - s->name = kdb_strdup(argv[1], GFP_KDB); - if (!s->name) + + mp = &kdb_macro->cmd; + mp->func = kdb_exec_defcmd; + mp->minlen = 0; + mp->flags = KDB_ENABLE_ALWAYS_SAFE; + mp->name = kdb_strdup(argv[1], GFP_KDB); + if (!mp->name) goto fail_name; - s->usage = kdb_strdup(argv[2], GFP_KDB); - if (!s->usage) + mp->usage = kdb_strdup(argv[2], GFP_KDB); + if (!mp->usage) goto fail_usage; - s->help = kdb_strdup(argv[3], GFP_KDB); - if (!s->help) + mp->help = kdb_strdup(argv[3], GFP_KDB); + if (!mp->help) goto fail_help; - if (s->usage[0] == '"') { - strcpy(s->usage, argv[2]+1); - s->usage[strlen(s->usage)-1] = '\0'; + if (mp->usage[0] == '"') { + strcpy(mp->usage, argv[2]+1); + mp->usage[strlen(mp->usage)-1] = '\0'; } - if (s->help[0] == '"') { - strcpy(s->help, argv[3]+1); - s->help[strlen(s->help)-1] = '\0'; + if (mp->help[0] == '"') { + strcpy(mp->help, argv[3]+1); + mp->help[strlen(mp->help)-1] = '\0'; } - ++defcmd_set_count; + + INIT_LIST_HEAD(&kdb_macro->statements); defcmd_in_progress = true; - kfree(save_defcmd_set); return 0; fail_help: - kfree(s->usage); + kfree(mp->usage); fail_usage: - kfree(s->name); + kfree(mp->name); fail_name: - kfree(defcmd_set); + kfree(kdb_macro); fail_defcmd: - kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]); - defcmd_set = save_defcmd_set; + kdb_printf("Could not allocate new kdb_macro entry for %s\n", argv[1]); return KDB_NOTIMP; } @@ -780,25 +780,31 @@ fail_defcmd: */ static int kdb_exec_defcmd(int argc, const char **argv) { - int i, ret; - struct defcmd_set *s; + int ret; + kdbtab_t *kp; + struct kdb_macro *kmp; + struct kdb_macro_statement *kms; + if (argc != 0) return KDB_ARGCOUNT; - for (s = defcmd_set, i = 0; i < defcmd_set_count; ++i, ++s) { - if (strcmp(s->name, argv[0]) == 0) + + list_for_each_entry(kp, &kdb_cmds_head, list_node) { + if (strcmp(kp->name, argv[0]) == 0) break; } - if (i == defcmd_set_count) { + if (list_entry_is_head(kp, &kdb_cmds_head, list_node)) { kdb_printf("kdb_exec_defcmd: could not find commands for %s\n", argv[0]); return KDB_NOTIMP; } - for (i = 0; i < s->count; ++i) { - /* Recursive use of kdb_parse, do not use argv after - * this point */ + kmp = container_of(kp, struct kdb_macro, cmd); + list_for_each_entry(kms, &kmp->statements, list_node) { + /* + * Recursive use of kdb_parse, do not use argv after this point. + */ argv = NULL; - kdb_printf("[%s]kdb> %s\n", s->name, s->command[i]); - ret = kdb_parse(s->command[i]); + kdb_printf("[%s]kdb> %s\n", kmp->cmd.name, kms->statement); + ret = kdb_parse(kms->statement); if (ret) return ret; } @@ -1009,11 +1015,11 @@ int kdb_parse(const char *cmdstr) * If this command is allowed to be abbreviated, * check to see if this is it. */ - if (tp->cmd_minlen && (strlen(argv[0]) <= tp->cmd_minlen) && - (strncmp(argv[0], tp->cmd_name, tp->cmd_minlen) == 0)) + if (tp->minlen && (strlen(argv[0]) <= tp->minlen) && + (strncmp(argv[0], tp->name, tp->minlen) == 0)) break; - if (strcmp(argv[0], tp->cmd_name) == 0) + if (strcmp(argv[0], tp->name) == 0) break; } @@ -1024,8 +1030,7 @@ int kdb_parse(const char *cmdstr) */ if (list_entry_is_head(tp, &kdb_cmds_head, list_node)) { list_for_each_entry(tp, &kdb_cmds_head, list_node) { - if (strncmp(argv[0], tp->cmd_name, - strlen(tp->cmd_name)) == 0) + if (strncmp(argv[0], tp->name, strlen(tp->name)) == 0) break; } } @@ -1033,19 +1038,19 @@ int kdb_parse(const char *cmdstr) if (!list_entry_is_head(tp, &kdb_cmds_head, list_node)) { int result; - if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1)) + if (!kdb_check_flags(tp->flags, kdb_cmd_enabled, argc <= 1)) return KDB_NOPERM; KDB_STATE_SET(CMD); - result = (*tp->cmd_func)(argc-1, (const char **)argv); + result = (*tp->func)(argc-1, (const char **)argv); if (result && ignore_errors && result > KDB_CMD_GO) result = 0; KDB_STATE_CLEAR(CMD); - if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS) + if (tp->flags & KDB_REPEAT_WITH_ARGS) return result; - argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0; + argc = tp->flags & KDB_REPEAT_NO_ARGS ? 1 : 0; if (argv[argc]) *(argv[argc]) = '\0'; return result; @@ -2412,12 +2417,12 @@ static int kdb_help(int argc, const char **argv) char *space = ""; if (KDB_FLAG(CMD_INTERRUPT)) return 0; - if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true)) + if (!kdb_check_flags(kt->flags, kdb_cmd_enabled, true)) continue; - if (strlen(kt->cmd_usage) > 20) + if (strlen(kt->usage) > 20) space = "\n "; - kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name, - kt->cmd_usage, space, kt->cmd_help); + kdb_printf("%-15.15s %-20s%s%s\n", kt->name, + kt->usage, space, kt->help); } return 0; } @@ -2613,56 +2618,32 @@ static int kdb_grep_help(int argc, const char **argv) return 0; } -/* - * kdb_register_flags - This function is used to register a kernel - * debugger command. - * Inputs: - * cmd Command name - * func Function to execute the command - * usage A simple usage string showing arguments - * help A simple help string describing command - * repeat Does the command auto repeat on enter? - * Returns: - * zero for success, one if a duplicate command. +/** + * kdb_register() - This function is used to register a kernel debugger + * command. + * @cmd: pointer to kdb command + * + * Note that it's the job of the caller to keep the memory for the cmd + * allocated until unregister is called. */ -int kdb_register_flags(char *cmd, - kdb_func_t func, - char *usage, - char *help, - short minlen, - kdb_cmdflags_t flags) +int kdb_register(kdbtab_t *cmd) { kdbtab_t *kp; list_for_each_entry(kp, &kdb_cmds_head, list_node) { - if (strcmp(kp->cmd_name, cmd) == 0) { - kdb_printf("Duplicate kdb command registered: " - "%s, func %px help %s\n", cmd, func, help); + if (strcmp(kp->name, cmd->name) == 0) { + kdb_printf("Duplicate kdb cmd: %s, func %p help %s\n", + cmd->name, cmd->func, cmd->help); return 1; } } - kp = kmalloc(sizeof(*kp), GFP_KDB); - if (!kp) { - kdb_printf("Could not allocate new kdb_command table\n"); - return 1; - } - - kp->cmd_name = cmd; - kp->cmd_func = func; - kp->cmd_usage = usage; - kp->cmd_help = help; - kp->cmd_minlen = minlen; - kp->cmd_flags = flags; - kp->is_dynamic = true; - - list_add_tail(&kp->list_node, &kdb_cmds_head); - + list_add_tail(&cmd->list_node, &kdb_cmds_head); return 0; } -EXPORT_SYMBOL_GPL(kdb_register_flags); +EXPORT_SYMBOL_GPL(kdb_register); -/* +/** * kdb_register_table() - This function is used to register a kdb command * table. * @kp: pointer to kdb command table @@ -2676,266 +2657,231 @@ void kdb_register_table(kdbtab_t *kp, size_t len) } } -/* - * kdb_register - Compatibility register function for commands that do - * not need to specify a repeat state. Equivalent to - * kdb_register_flags with flags set to 0. - * Inputs: - * cmd Command name - * func Function to execute the command - * usage A simple usage string showing arguments - * help A simple help string describing command - * Returns: - * zero for success, one if a duplicate command. +/** + * kdb_unregister() - This function is used to unregister a kernel debugger + * command. It is generally called when a module which + * implements kdb command is unloaded. + * @cmd: pointer to kdb command */ -int kdb_register(char *cmd, - kdb_func_t func, - char *usage, - char *help, - short minlen) +void kdb_unregister(kdbtab_t *cmd) { - return kdb_register_flags(cmd, func, usage, help, minlen, 0); -} -EXPORT_SYMBOL_GPL(kdb_register); - -/* - * kdb_unregister - This function is used to unregister a kernel - * debugger command. It is generally called when a module which - * implements kdb commands is unloaded. - * Inputs: - * cmd Command name - * Returns: - * zero for success, one command not registered. - */ -int kdb_unregister(char *cmd) -{ - kdbtab_t *kp; - - /* - * find the command. - */ - list_for_each_entry(kp, &kdb_cmds_head, list_node) { - if (strcmp(kp->cmd_name, cmd) == 0) { - list_del(&kp->list_node); - if (kp->is_dynamic) - kfree(kp); - return 0; - } - } - - /* Couldn't find it. */ - return 1; + list_del(&cmd->list_node); } EXPORT_SYMBOL_GPL(kdb_unregister); static kdbtab_t maintab[] = { - { .cmd_name = "md", - .cmd_func = kdb_md, - .cmd_usage = "<vaddr>", - .cmd_help = "Display Memory Contents, also mdWcN, e.g. md8c1", - .cmd_minlen = 1, - .cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, + { .name = "md", + .func = kdb_md, + .usage = "<vaddr>", + .help = "Display Memory Contents, also mdWcN, e.g. md8c1", + .minlen = 1, + .flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "mdr", - .cmd_func = kdb_md, - .cmd_usage = "<vaddr> <bytes>", - .cmd_help = "Display Raw Memory", - .cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, + { .name = "mdr", + .func = kdb_md, + .usage = "<vaddr> <bytes>", + .help = "Display Raw Memory", + .flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "mdp", - .cmd_func = kdb_md, - .cmd_usage = "<paddr> <bytes>", - .cmd_help = "Display Physical Memory", - .cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, + { .name = "mdp", + .func = kdb_md, + .usage = "<paddr> <bytes>", + .help = "Display Physical Memory", + .flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "mds", - .cmd_func = kdb_md, - .cmd_usage = "<vaddr>", - .cmd_help = "Display Memory Symbolically", - .cmd_flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, + { .name = "mds", + .func = kdb_md, + .usage = "<vaddr>", + .help = "Display Memory Symbolically", + .flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "mm", - .cmd_func = kdb_mm, - .cmd_usage = "<vaddr> <contents>", - .cmd_help = "Modify Memory Contents", - .cmd_flags = KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS, + { .name = "mm", + .func = kdb_mm, + .usage = "<vaddr> <contents>", + .help = "Modify Memory Contents", + .flags = KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS, }, - { .cmd_name = "go", - .cmd_func = kdb_go, - .cmd_usage = "[<vaddr>]", - .cmd_help = "Continue Execution", - .cmd_minlen = 1, - .cmd_flags = KDB_ENABLE_REG_WRITE | + { .name = "go", + .func = kdb_go, + .usage = "[<vaddr>]", + .help = "Continue Execution", + .minlen = 1, + .flags = KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS, }, - { .cmd_name = "rd", - .cmd_func = kdb_rd, - .cmd_usage = "", - .cmd_help = "Display Registers", - .cmd_flags = KDB_ENABLE_REG_READ, + { .name = "rd", + .func = kdb_rd, + .usage = "", + .help = "Display Registers", + .flags = KDB_ENABLE_REG_READ, }, - { .cmd_name = "rm", - .cmd_func = kdb_rm, - .cmd_usage = "<reg> <contents>", - .cmd_help = "Modify Registers", - .cmd_flags = KDB_ENABLE_REG_WRITE, + { .name = "rm", + .func = kdb_rm, + .usage = "<reg> <contents>", + .help = "Modify Registers", + .flags = KDB_ENABLE_REG_WRITE, }, - { .cmd_name = "ef", - .cmd_func = kdb_ef, - .cmd_usage = "<vaddr>", - .cmd_help = "Display exception frame", - .cmd_flags = KDB_ENABLE_MEM_READ, + { .name = "ef", + .func = kdb_ef, + .usage = "<vaddr>", + .help = "Display exception frame", + .flags = KDB_ENABLE_MEM_READ, }, - { .cmd_name = "bt", - .cmd_func = kdb_bt, - .cmd_usage = "[<vaddr>]", - .cmd_help = "Stack traceback", - .cmd_minlen = 1, - .cmd_flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS, + { .name = "bt", + .func = kdb_bt, + .usage = "[<vaddr>]", + .help = "Stack traceback", + .minlen = 1, + .flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS, }, - { .cmd_name = "btp", - .cmd_func = kdb_bt, - .cmd_usage = "<pid>", - .cmd_help = "Display stack for process <pid>", - .cmd_flags = KDB_ENABLE_INSPECT, + { .name = "btp", + .func = kdb_bt, + .usage = "<pid>", + .help = "Display stack for process <pid>", + .flags = KDB_ENABLE_INSPECT, }, - { .cmd_name = "bta", - .cmd_func = kdb_bt, - .cmd_usage = "[D|R|S|T|C|Z|E|U|I|M|A]", - .cmd_help = "Backtrace all processes matching state flag", - .cmd_flags = KDB_ENABLE_INSPECT, + { .name = "bta", + .func = kdb_bt, + .usage = "[D|R|S|T|C|Z|E|U|I|M|A]", + .help = "Backtrace all processes matching state flag", + .flags = KDB_ENABLE_INSPECT, }, - { .cmd_name = "btc", - .cmd_func = kdb_bt, - .cmd_usage = "", - .cmd_help = "Backtrace current process on each cpu", - .cmd_flags = KDB_ENABLE_INSPECT, + { .name = "btc", + .func = kdb_bt, + .usage = "", + .help = "Backtrace current process on each cpu", + .flags = KDB_ENABLE_INSPECT, }, - { .cmd_name = "btt", - .cmd_func = kdb_bt, - .cmd_usage = "<vaddr>", - .cmd_help = "Backtrace process given its struct task address", - .cmd_flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS, + { .name = "btt", + .func = kdb_bt, + .usage = "<vaddr>", + .help = "Backtrace process given its struct task address", + .flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS, }, - { .cmd_name = "env", - .cmd_func = kdb_env, - .cmd_usage = "", - .cmd_help = "Show environment variables", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "env", + .func = kdb_env, + .usage = "", + .help = "Show environment variables", + .flags = KDB_ENABLE_ALWAYS_SAFE, }, - { .cmd_name = "set", - .cmd_func = kdb_set, - .cmd_usage = "", - .cmd_help = "Set environment variables", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "set", + .func = kdb_set, + .usage = "", + .help = "Set environment variables", + .flags = KDB_ENABLE_ALWAYS_SAFE, }, - { .cmd_name = "help", - .cmd_func = kdb_help, - .cmd_usage = "", - .cmd_help = "Display Help Message", - .cmd_minlen = 1, - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "help", + .func = kdb_help, + .usage = "", + .help = "Display Help Message", + .minlen = 1, + .flags = KDB_ENABLE_ALWAYS_SAFE, }, - { .cmd_name = "?", - .cmd_func = kdb_help, - .cmd_usage = "", - .cmd_help = "Display Help Message", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "?", + .func = kdb_help, + .usage = "", + .help = "Display Help Message", + .flags = KDB_ENABLE_ALWAYS_SAFE, }, - { .cmd_name = "cpu", - .cmd_func = kdb_cpu, - .cmd_usage = "<cpunum>", - .cmd_help = "Switch to new cpu", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE_NO_ARGS, + { .name = "cpu", + .func = kdb_cpu, + .usage = "<cpunum>", + .help = "Switch to new cpu", + .flags = KDB_ENABLE_ALWAYS_SAFE_NO_ARGS, }, - { .cmd_name = "kgdb", - .cmd_func = kdb_kgdb, - .cmd_usage = "", - .cmd_help = "Enter kgdb mode", - .cmd_flags = 0, + { .name = "kgdb", + .func = kdb_kgdb, + .usage = "", + .help = "Enter kgdb mode", + .flags = 0, }, - { .cmd_name = "ps", - .cmd_func = kdb_ps, - .cmd_usage = "[<flags>|A]", - .cmd_help = "Display active task list", - .cmd_flags = KDB_ENABLE_INSPECT, + { .name = "ps", + .func = kdb_ps, + .usage = "[<flags>|A]", + .help = "Display active task list", + .flags = KDB_ENABLE_INSPECT, }, - { .cmd_name = "pid", - .cmd_func = kdb_pid, - .cmd_usage = "<pidnum>", - .cmd_help = "Switch to another task", - .cmd_flags = KDB_ENABLE_INSPECT, + { .name = "pid", + .func = kdb_pid, + .usage = "<pidnum>", + .help = "Switch to another task", + .flags = KDB_ENABLE_INSPECT, }, - { .cmd_name = "reboot", - .cmd_func = kdb_reboot, - .cmd_usage = "", - .cmd_help = "Reboot the machine immediately", - .cmd_flags = KDB_ENABLE_REBOOT, + { .name = "reboot", + .func = kdb_reboot, + .usage = "", + .help = "Reboot the machine immediately", + .flags = KDB_ENABLE_REBOOT, }, #if defined(CONFIG_MODULES) - { .cmd_name = "lsmod", - .cmd_func = kdb_lsmod, - .cmd_usage = "", - .cmd_help = "List loaded kernel modules", - .cmd_flags = KDB_ENABLE_INSPECT, + { .name = "lsmod", + .func = kdb_lsmod, + .usage = "", + .help = "List loaded kernel modules", + .flags = KDB_ENABLE_INSPECT, }, #endif #if defined(CONFIG_MAGIC_SYSRQ) - { .cmd_name = "sr", - .cmd_func = kdb_sr, - .cmd_usage = "<key>", - .cmd_help = "Magic SysRq key", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "sr", + .func = kdb_sr, + .usage = "<key>", + .help = "Magic SysRq key", + .flags = KDB_ENABLE_ALWAYS_SAFE, }, #endif #if defined(CONFIG_PRINTK) - { .cmd_name = "dmesg", - .cmd_func = kdb_dmesg, - .cmd_usage = "[lines]", - .cmd_help = "Display syslog buffer", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "dmesg", + .func = kdb_dmesg, + .usage = "[lines]", + .help = "Display syslog buffer", + .flags = KDB_ENABLE_ALWAYS_SAFE, }, #endif - { .cmd_name = "defcmd", - .cmd_func = kdb_defcmd, - .cmd_usage = "name \"usage\" \"help\"", - .cmd_help = "Define a set of commands, down to endefcmd", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "defcmd", + .func = kdb_defcmd, + .usage = "name \"usage\" \"help\"", + .help = "Define a set of commands, down to endefcmd", + /* + * Macros are always safe because when executed each + * internal command re-enters kdb_parse() and is safety + * checked individually. + */ + .flags = KDB_ENABLE_ALWAYS_SAFE, }, - { .cmd_name = "kill", - .cmd_func = kdb_kill, - .cmd_usage = "<-signal> <pid>", - .cmd_help = "Send a signal to a process", - .cmd_flags = KDB_ENABLE_SIGNAL, + { .name = "kill", + .func = kdb_kill, + .usage = "<-signal> <pid>", + .help = "Send a signal to a process", + .flags = KDB_ENABLE_SIGNAL, }, - { .cmd_name = "summary", - .cmd_func = kdb_summary, - .cmd_usage = "", - .cmd_help = "Summarize the system", - .cmd_minlen = 4, - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "summary", + .func = kdb_summary, + .usage = "", + .help = "Summarize the system", + .minlen = 4, + .flags = KDB_ENABLE_ALWAYS_SAFE, }, - { .cmd_name = "per_cpu", - .cmd_func = kdb_per_cpu, - .cmd_usage = "<sym> [<bytes>] [<cpu>]", - .cmd_help = "Display per_cpu variables", - .cmd_minlen = 3, - .cmd_flags = KDB_ENABLE_MEM_READ, + { .name = "per_cpu", + .func = kdb_per_cpu, + .usage = "<sym> [<bytes>] [<cpu>]", + .help = "Display per_cpu variables", + .minlen = 3, + .flags = KDB_ENABLE_MEM_READ, }, - { .cmd_name = "grephelp", - .cmd_func = kdb_grep_help, - .cmd_usage = "", - .cmd_help = "Display help on | grep", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + { .name = "grephelp", + .func = kdb_grep_help, + .usage = "", + .help = "Display help on | grep", + .flags = KDB_ENABLE_ALWAYS_SAFE, }, }; static kdbtab_t nmicmd = { - .cmd_name = "disable_nmi", - .cmd_func = kdb_disable_nmi, - .cmd_usage = "", - .cmd_help = "Disable NMI entry to KDB", - .cmd_flags = KDB_ENABLE_ALWAYS_SAFE, + .name = "disable_nmi", + .func = kdb_disable_nmi, + .usage = "", + .help = "Disable NMI entry to KDB", + .flags = KDB_ENABLE_ALWAYS_SAFE, }; /* Initialize the kdb command table. */ diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h index 170c69aedebb..629590084a0d 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -109,7 +109,6 @@ extern int kdbgetaddrarg(int, const char **, int*, unsigned long *, long *, char **); extern int kdbgetsymval(const char *, kdb_symtab_t *); extern int kdbnearsym(unsigned long, kdb_symtab_t *); -extern void kdbnearsym_cleanup(void); extern char *kdb_strdup(const char *str, gfp_t type); extern void kdb_symbol_print(unsigned long, const kdb_symtab_t *, unsigned int); @@ -165,19 +164,6 @@ typedef struct _kdb_bp { #ifdef CONFIG_KGDB_KDB extern kdb_bp_t kdb_breakpoints[/* KDB_MAXBPT */]; -/* The KDB shell command table */ -typedef struct _kdbtab { - char *cmd_name; /* Command name */ - kdb_func_t cmd_func; /* Function to execute command */ - char *cmd_usage; /* Usage String for this command */ - char *cmd_help; /* Help message for this command */ - short cmd_minlen; /* Minimum legal # command - * chars required */ - kdb_cmdflags_t cmd_flags; /* Command behaviour flags */ - struct list_head list_node; /* Command list */ - bool is_dynamic; /* Command table allocation type */ -} kdbtab_t; - extern void kdb_register_table(kdbtab_t *kp, size_t len); extern int kdb_bt(int, const char **); /* KDB display back trace */ @@ -233,10 +219,6 @@ extern struct task_struct *kdb_curr_task(int); #define GFP_KDB (in_dbg_master() ? GFP_ATOMIC : GFP_KERNEL) -extern void *debug_kmalloc(size_t size, gfp_t flags); -extern void debug_kfree(void *); -extern void debug_kusage(void); - extern struct task_struct *kdb_current_task; extern struct pt_regs *kdb_current_regs; diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c index 9f50d22d68e6..7507d9a8dc6a 100644 --- a/kernel/debug/kdb/kdb_support.c +++ b/kernel/debug/kdb/kdb_support.c @@ -10,7 +10,6 @@ * 03/02/13 added new 2.5 kallsyms <xavier.bru@bull.net> */ -#include <stdarg.h> #include <linux/types.h> #include <linux/sched.h> #include <linux/mm.h> @@ -52,48 +51,48 @@ int kdbgetsymval(const char *symname, kdb_symtab_t *symtab) } EXPORT_SYMBOL(kdbgetsymval); -static char *kdb_name_table[100]; /* arbitrary size */ - -/* - * kdbnearsym - Return the name of the symbol with the nearest address - * less than 'addr'. +/** + * kdbnearsym() - Return the name of the symbol with the nearest address + * less than @addr. + * @addr: Address to check for near symbol + * @symtab: Structure to receive results * - * Parameters: - * addr Address to check for symbol near - * symtab Structure to receive results - * Returns: - * 0 No sections contain this address, symtab zero filled - * 1 Address mapped to module/symbol/section, data in symtab - * Remarks: - * 2.6 kallsyms has a "feature" where it unpacks the name into a - * string. If that string is reused before the caller expects it - * then the caller sees its string change without warning. To - * avoid cluttering up the main kdb code with lots of kdb_strdup, - * tests and kfree calls, kdbnearsym maintains an LRU list of the - * last few unique strings. The list is sized large enough to - * hold active strings, no kdb caller of kdbnearsym makes more - * than ~20 later calls before using a saved value. + * WARNING: This function may return a pointer to a single statically + * allocated buffer (namebuf). kdb's unusual calling context (single + * threaded, all other CPUs halted) provides us sufficient locking for + * this to be safe. The only constraint imposed by the static buffer is + * that the caller must consume any previous reply prior to another call + * to lookup a new symbol. + * + * Note that, strictly speaking, some architectures may re-enter the kdb + * trap if the system turns out to be very badly damaged and this breaks + * the single-threaded assumption above. In these circumstances successful + * continuation and exit from the inner trap is unlikely to work and any + * user attempting this receives a prominent warning before being allowed + * to progress. In these circumstances we remain memory safe because + * namebuf[KSYM_NAME_LEN-1] will never change from '\0' although we do + * tolerate the possibility of garbled symbol display from the outer kdb + * trap. + * + * Return: + * * 0 - No sections contain this address, symtab zero filled + * * 1 - Address mapped to module/symbol/section, data in symtab */ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) { int ret = 0; unsigned long symbolsize = 0; unsigned long offset = 0; -#define knt1_size 128 /* must be >= kallsyms table size */ - char *knt1 = NULL; + static char namebuf[KSYM_NAME_LEN]; kdb_dbg_printf(AR, "addr=0x%lx, symtab=%px\n", addr, symtab); memset(symtab, 0, sizeof(*symtab)); if (addr < 4096) goto out; - knt1 = debug_kmalloc(knt1_size, GFP_ATOMIC); - if (!knt1) { - kdb_func_printf("addr=0x%lx cannot kmalloc knt1\n", addr); - goto out; - } + symtab->sym_name = kallsyms_lookup(addr, &symbolsize , &offset, - (char **)(&symtab->mod_name), knt1); + (char **)(&symtab->mod_name), namebuf); if (offset > 8*1024*1024) { symtab->sym_name = NULL; addr = offset = symbolsize = 0; @@ -102,63 +101,14 @@ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) symtab->sym_end = symtab->sym_start + symbolsize; ret = symtab->sym_name != NULL && *(symtab->sym_name) != '\0'; - if (ret) { - int i; - /* Another 2.6 kallsyms "feature". Sometimes the sym_name is - * set but the buffer passed into kallsyms_lookup is not used, - * so it contains garbage. The caller has to work out which - * buffer needs to be saved. - * - * What was Rusty smoking when he wrote that code? - */ - if (symtab->sym_name != knt1) { - strncpy(knt1, symtab->sym_name, knt1_size); - knt1[knt1_size-1] = '\0'; - } - for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { - if (kdb_name_table[i] && - strcmp(kdb_name_table[i], knt1) == 0) - break; - } - if (i >= ARRAY_SIZE(kdb_name_table)) { - debug_kfree(kdb_name_table[0]); - memmove(kdb_name_table, kdb_name_table+1, - sizeof(kdb_name_table[0]) * - (ARRAY_SIZE(kdb_name_table)-1)); - } else { - debug_kfree(knt1); - knt1 = kdb_name_table[i]; - memmove(kdb_name_table+i, kdb_name_table+i+1, - sizeof(kdb_name_table[0]) * - (ARRAY_SIZE(kdb_name_table)-i-1)); - } - i = ARRAY_SIZE(kdb_name_table) - 1; - kdb_name_table[i] = knt1; - symtab->sym_name = kdb_name_table[i]; - knt1 = NULL; - } - if (symtab->mod_name == NULL) symtab->mod_name = "kernel"; kdb_dbg_printf(AR, "returns %d symtab->sym_start=0x%lx, symtab->mod_name=%px, symtab->sym_name=%px (%s)\n", ret, symtab->sym_start, symtab->mod_name, symtab->sym_name, symtab->sym_name); - out: - debug_kfree(knt1); return ret; } -void kdbnearsym_cleanup(void) -{ - int i; - for (i = 0; i < ARRAY_SIZE(kdb_name_table); ++i) { - if (kdb_name_table[i]) { - debug_kfree(kdb_name_table[i]); - kdb_name_table[i] = NULL; - } - } -} - static char ks_namebuf[KSYM_NAME_LEN+1], ks_namebuf_prev[KSYM_NAME_LEN+1]; /* @@ -656,230 +606,6 @@ unsigned long kdb_task_state(const struct task_struct *p, unsigned long mask) return (mask & kdb_task_state_string(state)) != 0; } -/* Last ditch allocator for debugging, so we can still debug even when - * the GFP_ATOMIC pool has been exhausted. The algorithms are tuned - * for space usage, not for speed. One smallish memory pool, the free - * chain is always in ascending address order to allow coalescing, - * allocations are done in brute force best fit. - */ - -struct debug_alloc_header { - u32 next; /* offset of next header from start of pool */ - u32 size; - void *caller; -}; - -/* The memory returned by this allocator must be aligned, which means - * so must the header size. Do not assume that sizeof(struct - * debug_alloc_header) is a multiple of the alignment, explicitly - * calculate the overhead of this header, including the alignment. - * The rest of this code must not use sizeof() on any header or - * pointer to a header. - */ -#define dah_align 8 -#define dah_overhead ALIGN(sizeof(struct debug_alloc_header), dah_align) - -static u64 debug_alloc_pool_aligned[256*1024/dah_align]; /* 256K pool */ -static char *debug_alloc_pool = (char *)debug_alloc_pool_aligned; -static u32 dah_first, dah_first_call = 1, dah_used, dah_used_max; - -/* Locking is awkward. The debug code is called from all contexts, - * including non maskable interrupts. A normal spinlock is not safe - * in NMI context. Try to get the debug allocator lock, if it cannot - * be obtained after a second then give up. If the lock could not be - * previously obtained on this cpu then only try once. - * - * sparse has no annotation for "this function _sometimes_ acquires a - * lock", so fudge the acquire/release notation. - */ -static DEFINE_SPINLOCK(dap_lock); -static int get_dap_lock(void) - __acquires(dap_lock) -{ - static int dap_locked = -1; - int count; - if (dap_locked == smp_processor_id()) - count = 1; - else - count = 1000; - while (1) { - if (spin_trylock(&dap_lock)) { - dap_locked = -1; - return 1; - } - if (!count--) - break; - udelay(1000); - } - dap_locked = smp_processor_id(); - __acquire(dap_lock); - return 0; -} - -void *debug_kmalloc(size_t size, gfp_t flags) -{ - unsigned int rem, h_offset; - struct debug_alloc_header *best, *bestprev, *prev, *h; - void *p = NULL; - if (!get_dap_lock()) { - __release(dap_lock); /* we never actually got it */ - return NULL; - } - h = (struct debug_alloc_header *)(debug_alloc_pool + dah_first); - if (dah_first_call) { - h->size = sizeof(debug_alloc_pool_aligned) - dah_overhead; - dah_first_call = 0; - } - size = ALIGN(size, dah_align); - prev = best = bestprev = NULL; - while (1) { - if (h->size >= size && (!best || h->size < best->size)) { - best = h; - bestprev = prev; - if (h->size == size) - break; - } - if (!h->next) - break; - prev = h; - h = (struct debug_alloc_header *)(debug_alloc_pool + h->next); - } - if (!best) - goto out; - rem = best->size - size; - /* The pool must always contain at least one header */ - if (best->next == 0 && bestprev == NULL && rem < dah_overhead) - goto out; - if (rem >= dah_overhead) { - best->size = size; - h_offset = ((char *)best - debug_alloc_pool) + - dah_overhead + best->size; - h = (struct debug_alloc_header *)(debug_alloc_pool + h_offset); - h->size = rem - dah_overhead; - h->next = best->next; - } else - h_offset = best->next; - best->caller = __builtin_return_address(0); - dah_used += best->size; - dah_used_max = max(dah_used, dah_used_max); - if (bestprev) - bestprev->next = h_offset; - else - dah_first = h_offset; - p = (char *)best + dah_overhead; - memset(p, POISON_INUSE, best->size - 1); - *((char *)p + best->size - 1) = POISON_END; -out: - spin_unlock(&dap_lock); - return p; -} - -void debug_kfree(void *p) -{ - struct debug_alloc_header *h; - unsigned int h_offset; - if (!p) - return; - if ((char *)p < debug_alloc_pool || - (char *)p >= debug_alloc_pool + sizeof(debug_alloc_pool_aligned)) { - kfree(p); - return; - } - if (!get_dap_lock()) { - __release(dap_lock); /* we never actually got it */ - return; /* memory leak, cannot be helped */ - } - h = (struct debug_alloc_header *)((char *)p - dah_overhead); - memset(p, POISON_FREE, h->size - 1); - *((char *)p + h->size - 1) = POISON_END; - h->caller = NULL; - dah_used -= h->size; - h_offset = (char *)h - debug_alloc_pool; - if (h_offset < dah_first) { - h->next = dah_first; - dah_first = h_offset; - } else { - struct debug_alloc_header *prev; - unsigned int prev_offset; - prev = (struct debug_alloc_header *)(debug_alloc_pool + - dah_first); - while (1) { - if (!prev->next || prev->next > h_offset) - break; - prev = (struct debug_alloc_header *) - (debug_alloc_pool + prev->next); - } - prev_offset = (char *)prev - debug_alloc_pool; - if (prev_offset + dah_overhead + prev->size == h_offset) { - prev->size += dah_overhead + h->size; - memset(h, POISON_FREE, dah_overhead - 1); - *((char *)h + dah_overhead - 1) = POISON_END; - h = prev; - h_offset = prev_offset; - } else { - h->next = prev->next; - prev->next = h_offset; - } - } - if (h_offset + dah_overhead + h->size == h->next) { - struct debug_alloc_header *next; - next = (struct debug_alloc_header *) - (debug_alloc_pool + h->next); - h->size += dah_overhead + next->size; - h->next = next->next; - memset(next, POISON_FREE, dah_overhead - 1); - *((char *)next + dah_overhead - 1) = POISON_END; - } - spin_unlock(&dap_lock); -} - -void debug_kusage(void) -{ - struct debug_alloc_header *h_free, *h_used; -#ifdef CONFIG_IA64 - /* FIXME: using dah for ia64 unwind always results in a memory leak. - * Fix that memory leak first, then set debug_kusage_one_time = 1 for - * all architectures. - */ - static int debug_kusage_one_time; -#else - static int debug_kusage_one_time = 1; -#endif - if (!get_dap_lock()) { - __release(dap_lock); /* we never actually got it */ - return; - } - h_free = (struct debug_alloc_header *)(debug_alloc_pool + dah_first); - if (dah_first == 0 && - (h_free->size == sizeof(debug_alloc_pool_aligned) - dah_overhead || - dah_first_call)) - goto out; - if (!debug_kusage_one_time) - goto out; - debug_kusage_one_time = 0; - kdb_func_printf("debug_kmalloc memory leak dah_first %d\n", dah_first); - if (dah_first) { - h_used = (struct debug_alloc_header *)debug_alloc_pool; - kdb_func_printf("h_used %px size %d\n", h_used, h_used->size); - } - do { - h_used = (struct debug_alloc_header *) - ((char *)h_free + dah_overhead + h_free->size); - kdb_func_printf("h_used %px size %d caller %px\n", - h_used, h_used->size, h_used->caller); - h_free = (struct debug_alloc_header *) - (debug_alloc_pool + h_free->next); - } while (h_free->next); - h_used = (struct debug_alloc_header *) - ((char *)h_free + dah_overhead + h_free->size); - if ((char *)h_used - debug_alloc_pool != - sizeof(debug_alloc_pool_aligned)) - kdb_func_printf("h_used %px size %d caller %px\n", - h_used, h_used->size, h_used->caller); -out: - spin_unlock(&dap_lock); -} - /* Maintain a small stack of kdb_flags to allow recursion without disturbing * the global kdb state. */ diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 77b405508743..1b02179758cb 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -80,6 +80,19 @@ config SWIOTLB bool select NEED_DMA_MAP_STATE +config DMA_RESTRICTED_POOL + bool "DMA Restricted Pool" + depends on OF && OF_RESERVED_MEM && SWIOTLB + help + This enables support for restricted DMA pools which provide a level of + DMA memory protection on systems with limited hardware protection + capabilities, such as those lacking an IOMMU. + + For more information see + <Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt> + and <kernel/dma/swiotlb.c>. + If unsure, say "n". + # # Should be selected if we can mmap non-coherent mappings to userspace. # The only thing that is really required is a way to set an uncached bit @@ -93,6 +106,10 @@ config DMA_COHERENT_POOL select GENERIC_ALLOCATOR bool +config DMA_GLOBAL_POOL + select DMA_DECLARE_COHERENT + bool + config DMA_REMAP bool depends on MMU diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 794e76b03b34..25fc85a7aebe 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -20,8 +20,6 @@ struct dma_coherent_mem { bool use_dev_dma_pfn_offset; }; -static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; - static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev) { if (dev && dev->dma_mem) @@ -37,51 +35,44 @@ static inline dma_addr_t dma_get_device_base(struct device *dev, return mem->device_base; } -static int dma_init_coherent_memory(phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, - struct dma_coherent_mem **mem) +static struct dma_coherent_mem *dma_init_coherent_memory(phys_addr_t phys_addr, + dma_addr_t device_addr, size_t size, bool use_dma_pfn_offset) { - struct dma_coherent_mem *dma_mem = NULL; - void *mem_base = NULL; + struct dma_coherent_mem *dma_mem; int pages = size >> PAGE_SHIFT; int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); - int ret; + void *mem_base; - if (!size) { - ret = -EINVAL; - goto out; - } + if (!size) + return ERR_PTR(-EINVAL); mem_base = memremap(phys_addr, size, MEMREMAP_WC); - if (!mem_base) { - ret = -EINVAL; - goto out; - } + if (!mem_base) + return ERR_PTR(-EINVAL); + dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); - if (!dma_mem) { - ret = -ENOMEM; - goto out; - } + if (!dma_mem) + goto out_unmap_membase; dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!dma_mem->bitmap) { - ret = -ENOMEM; - goto out; - } + if (!dma_mem->bitmap) + goto out_free_dma_mem; dma_mem->virt_base = mem_base; dma_mem->device_base = device_addr; dma_mem->pfn_base = PFN_DOWN(phys_addr); dma_mem->size = pages; + dma_mem->use_dev_dma_pfn_offset = use_dma_pfn_offset; spin_lock_init(&dma_mem->spinlock); - *mem = dma_mem; - return 0; + return dma_mem; -out: +out_free_dma_mem: kfree(dma_mem); - if (mem_base) - memunmap(mem_base); - return ret; +out_unmap_membase: + memunmap(mem_base); + pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %zd MiB\n", + &phys_addr, size / SZ_1M); + return ERR_PTR(-ENOMEM); } static void dma_release_coherent_memory(struct dma_coherent_mem *mem) @@ -130,9 +121,9 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, struct dma_coherent_mem *mem; int ret; - ret = dma_init_coherent_memory(phys_addr, device_addr, size, &mem); - if (ret) - return ret; + mem = dma_init_coherent_memory(phys_addr, device_addr, size, false); + if (IS_ERR(mem)) + return PTR_ERR(mem); ret = dma_assign_coherent_memory(dev, mem); if (ret) @@ -198,16 +189,6 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, return 1; } -void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle) -{ - if (!dma_coherent_default_memory) - return NULL; - - return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, - dma_handle); -} - static int __dma_release_from_coherent(struct dma_coherent_mem *mem, int order, void *vaddr) { @@ -243,15 +224,6 @@ int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr) return __dma_release_from_coherent(mem, order, vaddr); } -int dma_release_from_global_coherent(int order, void *vaddr) -{ - if (!dma_coherent_default_memory) - return 0; - - return __dma_release_from_coherent(dma_coherent_default_memory, order, - vaddr); -} - static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem, struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { @@ -297,6 +269,28 @@ int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret); } +#ifdef CONFIG_DMA_GLOBAL_POOL +static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; + +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle) +{ + if (!dma_coherent_default_memory) + return NULL; + + return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, + dma_handle); +} + +int dma_release_from_global_coherent(int order, void *vaddr) +{ + if (!dma_coherent_default_memory) + return 0; + + return __dma_release_from_coherent(dma_coherent_default_memory, order, + vaddr); +} + int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { @@ -307,6 +301,19 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, vaddr, size, ret); } +int dma_init_global_coherent(phys_addr_t phys_addr, size_t size) +{ + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(phys_addr, phys_addr, size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + dma_coherent_default_memory = mem; + pr_info("DMA: default coherent area is set\n"); + return 0; +} +#endif /* CONFIG_DMA_GLOBAL_POOL */ + /* * Support for reserved memory regions defined in device tree */ @@ -315,25 +322,22 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, #include <linux/of_fdt.h> #include <linux/of_reserved_mem.h> +#ifdef CONFIG_DMA_GLOBAL_POOL static struct reserved_mem *dma_reserved_default_memory __initdata; +#endif static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) { - struct dma_coherent_mem *mem = rmem->priv; - int ret; - - if (!mem) { - ret = dma_init_coherent_memory(rmem->base, rmem->base, - rmem->size, &mem); - if (ret) { - pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n", - &rmem->base, (unsigned long)rmem->size / SZ_1M); - return ret; - } + if (!rmem->priv) { + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(rmem->base, rmem->base, + rmem->size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + rmem->priv = mem; } - mem->use_dev_dma_pfn_offset = true; - rmem->priv = mem; - dma_assign_coherent_memory(dev, mem); + dma_assign_coherent_memory(dev, rmem->priv); return 0; } @@ -361,7 +365,9 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) pr_err("Reserved memory: regions without no-map are not yet supported\n"); return -EINVAL; } +#endif +#ifdef CONFIG_DMA_GLOBAL_POOL if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) { WARN(dma_reserved_default_memory, "Reserved memory: region for default DMA coherent area is redefined\n"); @@ -375,31 +381,16 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) return 0; } +#ifdef CONFIG_DMA_GLOBAL_POOL static int __init dma_init_reserved_memory(void) { - const struct reserved_mem_ops *ops; - int ret; - if (!dma_reserved_default_memory) return -ENOMEM; - - ops = dma_reserved_default_memory->ops; - - /* - * We rely on rmem_dma_device_init() does not propagate error of - * dma_assign_coherent_memory() for "NULL" device. - */ - ret = ops->device_init(dma_reserved_default_memory, NULL); - - if (!ret) { - dma_coherent_default_memory = dma_reserved_default_memory->priv; - pr_info("DMA: default coherent area is set\n"); - } - - return ret; + return dma_init_global_coherent(dma_reserved_default_memory->base, + dma_reserved_default_memory->size); } - core_initcall(dma_init_reserved_memory); +#endif /* CONFIG_DMA_GLOBAL_POOL */ RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); #endif diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index dadae6255d05..7a14ca29c377 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -552,7 +552,7 @@ static void active_cacheline_remove(struct dma_debug_entry *entry) * Wrapper function for adding an entry to the hash. * This function takes care of locking itself. */ -static void add_dma_entry(struct dma_debug_entry *entry) +static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs) { struct hash_bucket *bucket; unsigned long flags; @@ -566,8 +566,9 @@ static void add_dma_entry(struct dma_debug_entry *entry) if (rc == -ENOMEM) { pr_err("cacheline tracking ENOMEM, dma-debug disabled\n"); global_disable = true; - } else if (rc == -EEXIST) { - pr_err("cacheline tracking EEXIST, overlapping mappings aren't supported\n"); + } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { + err_printk(entry->dev, entry, + "cacheline tracking EEXIST, overlapping mappings aren't supported\n"); } } @@ -792,7 +793,7 @@ static int dump_show(struct seq_file *seq, void *v) } DEFINE_SHOW_ATTRIBUTE(dump); -static void dma_debug_fs_init(void) +static int __init dma_debug_fs_init(void) { struct dentry *dentry = debugfs_create_dir("dma-api", NULL); @@ -805,7 +806,10 @@ static void dma_debug_fs_init(void) debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries); debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops); debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops); + + return 0; } +core_initcall_sync(dma_debug_fs_init); static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) { @@ -890,8 +894,6 @@ static int dma_debug_init(void) spin_lock_init(&dma_entry_hash[i].lock); } - dma_debug_fs_init(); - nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES); for (i = 0; i < nr_pages; ++i) dma_debug_create_entries(GFP_KERNEL); @@ -1064,20 +1066,10 @@ static void check_for_stack(struct device *dev, } } -static inline bool overlap(void *addr, unsigned long len, void *start, void *end) -{ - unsigned long a1 = (unsigned long)addr; - unsigned long b1 = a1 + len; - unsigned long a2 = (unsigned long)start; - unsigned long b2 = (unsigned long)end; - - return !(b1 <= a2 || a1 >= b2); -} - static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len) { - if (overlap(addr, len, _stext, _etext) || - overlap(addr, len, __start_rodata, __end_rodata)) + if (memory_intersects(_stext, _etext, addr, len) || + memory_intersects(__start_rodata, __end_rodata, addr, len)) err_printk(dev, NULL, "device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len); } @@ -1199,7 +1191,8 @@ void debug_dma_map_single(struct device *dev, const void *addr, EXPORT_SYMBOL(debug_dma_map_single); void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, - size_t size, int direction, dma_addr_t dma_addr) + size_t size, int direction, dma_addr_t dma_addr, + unsigned long attrs) { struct dma_debug_entry *entry; @@ -1230,7 +1223,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, check_for_illegal_area(dev, addr, size); } - add_dma_entry(entry); + add_dma_entry(entry, attrs); } void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) @@ -1288,7 +1281,8 @@ void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, } void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, - int nents, int mapped_ents, int direction) + int nents, int mapped_ents, int direction, + unsigned long attrs) { struct dma_debug_entry *entry; struct scatterlist *s; @@ -1297,6 +1291,12 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, if (unlikely(dma_debug_disabled())) return; + for_each_sg(sg, s, nents, i) { + check_for_stack(dev, sg_page(s), s->offset); + if (!PageHighMem(sg_page(s))) + check_for_illegal_area(dev, sg_virt(s), s->length); + } + for_each_sg(sg, s, mapped_ents, i) { entry = dma_entry_alloc(); if (!entry) @@ -1312,15 +1312,9 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, entry->sg_call_ents = nents; entry->sg_mapped_ents = mapped_ents; - check_for_stack(dev, sg_page(s), s->offset); - - if (!PageHighMem(sg_page(s))) { - check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s)); - } - check_sg_segment(dev, s); - add_dma_entry(entry); + add_dma_entry(entry, attrs); } } @@ -1376,7 +1370,8 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, } void debug_dma_alloc_coherent(struct device *dev, size_t size, - dma_addr_t dma_addr, void *virt) + dma_addr_t dma_addr, void *virt, + unsigned long attrs) { struct dma_debug_entry *entry; @@ -1406,7 +1401,7 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size, else entry->pfn = page_to_pfn(virt_to_page(virt)); - add_dma_entry(entry); + add_dma_entry(entry, attrs); } void debug_dma_free_coherent(struct device *dev, size_t size, @@ -1437,7 +1432,8 @@ void debug_dma_free_coherent(struct device *dev, size_t size, } void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, - int direction, dma_addr_t dma_addr) + int direction, dma_addr_t dma_addr, + unsigned long attrs) { struct dma_debug_entry *entry; @@ -1457,7 +1453,7 @@ void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, entry->direction = direction; entry->map_err_type = MAP_ERR_NOT_CHECKED; - add_dma_entry(entry); + add_dma_entry(entry, attrs); } void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr, diff --git a/kernel/dma/debug.h b/kernel/dma/debug.h index 83643b3010b2..f525197d3cae 100644 --- a/kernel/dma/debug.h +++ b/kernel/dma/debug.h @@ -11,26 +11,30 @@ #ifdef CONFIG_DMA_API_DEBUG extern void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, size_t size, - int direction, dma_addr_t dma_addr); + int direction, dma_addr_t dma_addr, + unsigned long attrs); extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, size_t size, int direction); extern void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, - int nents, int mapped_ents, int direction); + int nents, int mapped_ents, int direction, + unsigned long attrs); extern void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nelems, int dir); extern void debug_dma_alloc_coherent(struct device *dev, size_t size, - dma_addr_t dma_addr, void *virt); + dma_addr_t dma_addr, void *virt, + unsigned long attrs); extern void debug_dma_free_coherent(struct device *dev, size_t size, void *virt, dma_addr_t addr); extern void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, int direction, - dma_addr_t dma_addr); + dma_addr_t dma_addr, + unsigned long attrs); extern void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr, size_t size, int direction); @@ -53,7 +57,8 @@ extern void debug_dma_sync_sg_for_device(struct device *dev, #else /* CONFIG_DMA_API_DEBUG */ static inline void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, size_t size, - int direction, dma_addr_t dma_addr) + int direction, dma_addr_t dma_addr, + unsigned long attrs) { } @@ -63,7 +68,8 @@ static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, } static inline void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, - int nents, int mapped_ents, int direction) + int nents, int mapped_ents, int direction, + unsigned long attrs) { } @@ -74,7 +80,8 @@ static inline void debug_dma_unmap_sg(struct device *dev, } static inline void debug_dma_alloc_coherent(struct device *dev, size_t size, - dma_addr_t dma_addr, void *virt) + dma_addr_t dma_addr, void *virt, + unsigned long attrs) { } @@ -85,7 +92,8 @@ static inline void debug_dma_free_coherent(struct device *dev, size_t size, static inline void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, int direction, - dma_addr_t dma_addr) + dma_addr_t dma_addr, + unsigned long attrs) { } diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index f737e3347059..4c6c5e0635e3 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -75,6 +75,15 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit); } +static void __dma_direct_free_pages(struct device *dev, struct page *page, + size_t size) +{ + if (IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL) && + swiotlb_free(dev, page, size)) + return; + dma_free_contiguous(dev, page, size); +} + static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, gfp_t gfp) { @@ -86,6 +95,16 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask, &phys_limit); + if (IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL) && + is_swiotlb_for_alloc(dev)) { + page = swiotlb_alloc(dev, size); + if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + __dma_direct_free_pages(dev, page, size); + return NULL; + } + return page; + } + page = dma_alloc_contiguous(dev, size, gfp); if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { dma_free_contiguous(dev, page, size); @@ -142,7 +161,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, gfp |= __GFP_NOWARN; if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev)) { + !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) { page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO); if (!page) return NULL; @@ -156,17 +175,28 @@ void *dma_direct_alloc(struct device *dev, size_t size, if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev)) + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev) && + !is_swiotlb_for_alloc(dev)) return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); + if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev)) + return dma_alloc_from_global_coherent(dev, size, dma_handle); + /* * Remapping or decrypting memory may block. If either is required and * we can't block, allocate the memory from the atomic pools. + * If restricted DMA (i.e., is_swiotlb_for_alloc) is required, one must + * set up another device coherent pool by shared-dma-pool and use + * dma_alloc_from_dev_coherent instead. */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && !gfpflags_allow_blocking(gfp) && (force_dma_unencrypted(dev) || - (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !dev_is_dma_coherent(dev)))) + (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !dev_is_dma_coherent(dev))) && + !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); /* we always manually zero the memory once we are done */ @@ -237,7 +267,7 @@ out_encrypt_pages: return NULL; } out_free_pages: - dma_free_contiguous(dev, page, size); + __dma_direct_free_pages(dev, page, size); return NULL; } @@ -247,7 +277,7 @@ void dma_direct_free(struct device *dev, size_t size, unsigned int page_order = get_order(size); if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev)) { + !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) { /* cpu_addr is a struct page cookie, not a kernel address */ dma_free_contiguous(dev, cpu_addr, size); return; @@ -255,11 +285,20 @@ void dma_direct_free(struct device *dev, size_t size, if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev)) { + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev) && + !is_swiotlb_for_alloc(dev)) { arch_dma_free(dev, size, cpu_addr, dma_addr, attrs); return; } + if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev)) { + if (!dma_release_from_global_coherent(page_order, cpu_addr)) + WARN_ON_ONCE(1); + return; + } + /* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size))) @@ -273,7 +312,7 @@ void dma_direct_free(struct device *dev, size_t size, else if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_CLEAR_UNCACHED)) arch_dma_clear_uncached(cpu_addr, size); - dma_free_contiguous(dev, dma_direct_to_page(dev, dma_addr), size); + __dma_direct_free_pages(dev, dma_direct_to_page(dev, dma_addr), size); } struct page *dma_direct_alloc_pages(struct device *dev, size_t size, @@ -283,7 +322,8 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, void *ret; if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp)) + force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && + !is_swiotlb_for_alloc(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); page = __dma_direct_alloc_pages(dev, size, gfp); @@ -310,7 +350,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); return page; out_free_pages: - dma_free_contiguous(dev, page, size); + __dma_direct_free_pages(dev, page, size); return NULL; } @@ -329,7 +369,7 @@ void dma_direct_free_pages(struct device *dev, size_t size, if (force_dma_unencrypted(dev)) set_memory_encrypted((unsigned long)vaddr, 1 << page_order); - dma_free_contiguous(dev, page, size); + __dma_direct_free_pages(dev, page, size); } #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ @@ -343,7 +383,7 @@ void dma_direct_sync_sg_for_device(struct device *dev, for_each_sg(sgl, sg, nents, i) { phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg)); - if (unlikely(is_swiotlb_buffer(paddr))) + if (unlikely(is_swiotlb_buffer(dev, paddr))) swiotlb_sync_single_for_device(dev, paddr, sg->length, dir); @@ -369,7 +409,7 @@ void dma_direct_sync_sg_for_cpu(struct device *dev, if (!dev_is_dma_coherent(dev)) arch_sync_dma_for_cpu(paddr, sg->length, dir); - if (unlikely(is_swiotlb_buffer(paddr))) + if (unlikely(is_swiotlb_buffer(dev, paddr))) swiotlb_sync_single_for_cpu(dev, paddr, sg->length, dir); @@ -411,7 +451,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, out_unmap: dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); - return 0; + return -EIO; } dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, @@ -462,6 +502,8 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma, if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) return ret; + if (dma_mmap_from_global_coherent(vma, cpu_addr, size, &ret)) + return ret; if (vma->vm_pgoff >= count || user_count > count - vma->vm_pgoff) return -ENXIO; @@ -495,8 +537,8 @@ int dma_direct_supported(struct device *dev, u64 mask) size_t dma_direct_max_mapping_size(struct device *dev) { /* If SWIOTLB is active, use its maximum mapping size */ - if (is_swiotlb_active() && - (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE)) + if (is_swiotlb_active(dev) && + (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev))) return swiotlb_max_mapping_size(dev); return SIZE_MAX; } @@ -504,7 +546,7 @@ size_t dma_direct_max_mapping_size(struct device *dev) bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr) { return !dev_is_dma_coherent(dev) || - is_swiotlb_buffer(dma_to_phys(dev, dma_addr)); + is_swiotlb_buffer(dev, dma_to_phys(dev, dma_addr)); } /** diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h index 50afc05b6f1d..4632b0f4f72e 100644 --- a/kernel/dma/direct.h +++ b/kernel/dma/direct.h @@ -56,7 +56,7 @@ static inline void dma_direct_sync_single_for_device(struct device *dev, { phys_addr_t paddr = dma_to_phys(dev, addr); - if (unlikely(is_swiotlb_buffer(paddr))) + if (unlikely(is_swiotlb_buffer(dev, paddr))) swiotlb_sync_single_for_device(dev, paddr, size, dir); if (!dev_is_dma_coherent(dev)) @@ -73,7 +73,7 @@ static inline void dma_direct_sync_single_for_cpu(struct device *dev, arch_sync_dma_for_cpu_all(); } - if (unlikely(is_swiotlb_buffer(paddr))) + if (unlikely(is_swiotlb_buffer(dev, paddr))) swiotlb_sync_single_for_cpu(dev, paddr, size, dir); if (dir == DMA_FROM_DEVICE) @@ -87,7 +87,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev, phys_addr_t phys = page_to_phys(page) + offset; dma_addr_t dma_addr = phys_to_dma(dev, phys); - if (unlikely(swiotlb_force == SWIOTLB_FORCE)) + if (is_swiotlb_force_bounce(dev)) return swiotlb_map(dev, phys, size, dir, attrs); if (unlikely(!dma_capable(dev, dma_addr, size, true))) { @@ -113,7 +113,7 @@ static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) dma_direct_sync_single_for_cpu(dev, addr, size, dir); - if (unlikely(is_swiotlb_buffer(phys))) + if (unlikely(is_swiotlb_buffer(dev, phys))) swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); } #endif /* _KERNEL_DMA_DIRECT_H */ diff --git a/kernel/dma/dummy.c b/kernel/dma/dummy.c index eacd4c5b10bf..b492d59ac77e 100644 --- a/kernel/dma/dummy.c +++ b/kernel/dma/dummy.c @@ -22,7 +22,7 @@ static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl, int nelems, enum dma_data_direction dir, unsigned long attrs) { - return 0; + return -EINVAL; } static int dma_dummy_supported(struct device *hwdev, u64 mask) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 2b06a809d0b9..8349a9f2c345 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -156,7 +156,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else addr = ops->map_page(dev, page, offset, size, dir, attrs); - debug_dma_map_page(dev, page, offset, size, dir, addr); + debug_dma_map_page(dev, page, offset, size, dir, addr, attrs); return addr; } @@ -177,12 +177,8 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, } EXPORT_SYMBOL(dma_unmap_page_attrs); -/* - * dma_maps_sg_attrs returns 0 on error and > 0 on success. - * It should never return a value < 0. - */ -int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction dir, unsigned long attrs) +static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); int ents; @@ -197,13 +193,82 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); else ents = ops->map_sg(dev, sg, nents, dir, attrs); - BUG_ON(ents < 0); - debug_dma_map_sg(dev, sg, nents, ents, dir); + + if (ents > 0) + debug_dma_map_sg(dev, sg, nents, ents, dir, attrs); + else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM && + ents != -EIO)) + return -EIO; return ents; } + +/** + * dma_map_sg_attrs - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sg: The sg_table object describing the buffer + * @nents: Number of entries to map + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist passed in the sg argument with + * nents segments for the @dir DMA operation by the @dev device. + * + * Returns the number of mapped entries (which can be less than nents) + * on success. Zero is returned for any error. + * + * dma_unmap_sg_attrs() should be used to unmap the buffer with the + * original sg and original nents (not the value returned by this funciton). + */ +unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + int ret; + + ret = __dma_map_sg_attrs(dev, sg, nents, dir, attrs); + if (ret < 0) + return 0; + return ret; +} EXPORT_SYMBOL(dma_map_sg_attrs); +/** + * dma_map_sgtable - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist stored in the given sg_table + * object for the @dir DMA operation by the @dev device. After success, the + * ownership for the buffer is transferred to the DMA domain. One has to + * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the + * ownership of the buffer back to the CPU domain before touching the + * buffer by the CPU. + * + * Returns 0 on success or a negative error code on error. The following + * error codes are supported with the given meaning: + * + * -EINVAL An invalid argument, unaligned access or other error + * in usage. Will not succeed if retried. + * -ENOMEM Insufficient resources (like memory or IOVA space) to + * complete the mapping. Should succeed if retried later. + * -EIO Legacy error code with an unknown meaning. eg. this is + * returned if a lower level call returned DMA_MAPPING_ERROR. + */ +int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + int nents; + + nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); + if (nents < 0) + return nents; + sgt->nents = nents; + return 0; +} +EXPORT_SYMBOL_GPL(dma_map_sgtable); + void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs) @@ -240,7 +305,7 @@ dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, else if (ops->map_resource) addr = ops->map_resource(dev, phys_addr, size, dir, attrs); - debug_dma_map_resource(dev, phys_addr, size, dir, addr); + debug_dma_map_resource(dev, phys_addr, size, dir, addr, attrs); return addr; } EXPORT_SYMBOL(dma_map_resource); @@ -445,7 +510,7 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, else return NULL; - debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr); + debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr, attrs); return cpu_addr; } EXPORT_SYMBOL(dma_alloc_attrs); @@ -501,7 +566,7 @@ struct page *dma_alloc_pages(struct device *dev, size_t size, struct page *page = __dma_alloc_pages(dev, size, dma_handle, dir, gfp); if (page) - debug_dma_map_page(dev, page, 0, size, dir, *dma_handle); + debug_dma_map_page(dev, page, 0, size, dir, *dma_handle, 0); return page; } EXPORT_SYMBOL_GPL(dma_alloc_pages); @@ -579,7 +644,7 @@ struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size, if (sgt) { sgt->nents = 1; - debug_dma_map_sg(dev, sgt->sgl, sgt->orig_nents, 1, dir); + debug_dma_map_sg(dev, sgt->sgl, sgt->orig_nents, 1, dir, attrs); } return sgt; } diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index e50df8d8f87e..87c40517e822 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -39,6 +39,13 @@ #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> #endif +#ifdef CONFIG_DMA_RESTRICTED_POOL +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/of_reserved_mem.h> +#include <linux/slab.h> +#endif #include <asm/io.h> #include <asm/dma.h> @@ -63,7 +70,7 @@ enum swiotlb_force swiotlb_force; -struct io_tlb_mem *io_tlb_default_mem; +struct io_tlb_mem io_tlb_default_mem; /* * Max segment that we can provide which (if pages are contingous) will @@ -94,7 +101,7 @@ early_param("swiotlb", setup_io_tlb_npages); unsigned int swiotlb_max_segment(void) { - return io_tlb_default_mem ? max_segment : 0; + return io_tlb_default_mem.nslabs ? max_segment : 0; } EXPORT_SYMBOL_GPL(swiotlb_max_segment); @@ -127,9 +134,9 @@ void __init swiotlb_adjust_size(unsigned long size) void swiotlb_print_info(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; - if (!mem) { + if (!mem->nslabs) { pr_warn("No low mem\n"); return; } @@ -156,11 +163,11 @@ static inline unsigned long nr_slots(u64 val) */ void __init swiotlb_update_mem_attributes(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; void *vaddr; unsigned long bytes; - if (!mem || mem->late_alloc) + if (!mem->nslabs || mem->late_alloc) return; vaddr = phys_to_virt(mem->start); bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); @@ -168,36 +175,50 @@ void __init swiotlb_update_mem_attributes(void) memset(vaddr, 0, bytes); } -int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) +static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, + unsigned long nslabs, bool late_alloc) { + void *vaddr = phys_to_virt(start); unsigned long bytes = nslabs << IO_TLB_SHIFT, i; - struct io_tlb_mem *mem; - size_t alloc_size; - - if (swiotlb_force == SWIOTLB_NO_FORCE) - return 0; - - /* protect against double initialization */ - if (WARN_ON_ONCE(io_tlb_default_mem)) - return -ENOMEM; - alloc_size = PAGE_ALIGN(struct_size(mem, slots, nslabs)); - mem = memblock_alloc(alloc_size, PAGE_SIZE); - if (!mem) - panic("%s: Failed to allocate %zu bytes align=0x%lx\n", - __func__, alloc_size, PAGE_SIZE); mem->nslabs = nslabs; - mem->start = __pa(tlb); + mem->start = start; mem->end = mem->start + bytes; mem->index = 0; + mem->late_alloc = late_alloc; + + if (swiotlb_force == SWIOTLB_FORCE) + mem->force_bounce = true; + spin_lock_init(&mem->lock); for (i = 0; i < mem->nslabs; i++) { mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i); mem->slots[i].orig_addr = INVALID_PHYS_ADDR; mem->slots[i].alloc_size = 0; } + memset(vaddr, 0, bytes); +} + +int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) +{ + struct io_tlb_mem *mem = &io_tlb_default_mem; + size_t alloc_size; + + if (swiotlb_force == SWIOTLB_NO_FORCE) + return 0; + + /* protect against double initialization */ + if (WARN_ON_ONCE(mem->nslabs)) + return -ENOMEM; + + alloc_size = PAGE_ALIGN(array_size(sizeof(*mem->slots), nslabs)); + mem->slots = memblock_alloc(alloc_size, PAGE_SIZE); + if (!mem->slots) + panic("%s: Failed to allocate %zu bytes align=0x%lx\n", + __func__, alloc_size, PAGE_SIZE); + + swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false); - io_tlb_default_mem = mem; if (verbose) swiotlb_print_info(); swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT); @@ -282,37 +303,24 @@ swiotlb_late_init_with_default_size(size_t default_size) int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) { - unsigned long bytes = nslabs << IO_TLB_SHIFT, i; - struct io_tlb_mem *mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; + unsigned long bytes = nslabs << IO_TLB_SHIFT; if (swiotlb_force == SWIOTLB_NO_FORCE) return 0; /* protect against double initialization */ - if (WARN_ON_ONCE(io_tlb_default_mem)) + if (WARN_ON_ONCE(mem->nslabs)) return -ENOMEM; - mem = (void *)__get_free_pages(GFP_KERNEL, - get_order(struct_size(mem, slots, nslabs))); - if (!mem) + mem->slots = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + get_order(array_size(sizeof(*mem->slots), nslabs))); + if (!mem->slots) return -ENOMEM; - mem->nslabs = nslabs; - mem->start = virt_to_phys(tlb); - mem->end = mem->start + bytes; - mem->index = 0; - mem->late_alloc = 1; - spin_lock_init(&mem->lock); - for (i = 0; i < mem->nslabs; i++) { - mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i); - mem->slots[i].orig_addr = INVALID_PHYS_ADDR; - mem->slots[i].alloc_size = 0; - } - set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); - memset(tlb, 0, bytes); + swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true); - io_tlb_default_mem = mem; swiotlb_print_info(); swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT); return 0; @@ -320,18 +328,28 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) void __init swiotlb_exit(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; - size_t size; + struct io_tlb_mem *mem = &io_tlb_default_mem; + unsigned long tbl_vaddr; + size_t tbl_size, slots_size; - if (!mem) + if (!mem->nslabs) return; - size = struct_size(mem, slots, mem->nslabs); - if (mem->late_alloc) - free_pages((unsigned long)mem, get_order(size)); - else - memblock_free_late(__pa(mem), PAGE_ALIGN(size)); - io_tlb_default_mem = NULL; + pr_info("tearing down default memory pool\n"); + tbl_vaddr = (unsigned long)phys_to_virt(mem->start); + tbl_size = PAGE_ALIGN(mem->end - mem->start); + slots_size = PAGE_ALIGN(array_size(sizeof(*mem->slots), mem->nslabs)); + + set_memory_encrypted(tbl_vaddr, tbl_size >> PAGE_SHIFT); + if (mem->late_alloc) { + free_pages(tbl_vaddr, get_order(tbl_size)); + free_pages((unsigned long)mem->slots, get_order(slots_size)); + } else { + memblock_free_late(mem->start, tbl_size); + memblock_free_late(__pa(mem->slots), slots_size); + } + + memset(mem, 0, sizeof(*mem)); } /* @@ -348,19 +366,33 @@ static unsigned int swiotlb_align_offset(struct device *dev, u64 addr) static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT; phys_addr_t orig_addr = mem->slots[index].orig_addr; size_t alloc_size = mem->slots[index].alloc_size; unsigned long pfn = PFN_DOWN(orig_addr); unsigned char *vaddr = phys_to_virt(tlb_addr); - unsigned int tlb_offset; + unsigned int tlb_offset, orig_addr_offset; if (orig_addr == INVALID_PHYS_ADDR) return; - tlb_offset = (tlb_addr & (IO_TLB_SIZE - 1)) - - swiotlb_align_offset(dev, orig_addr); + tlb_offset = tlb_addr & (IO_TLB_SIZE - 1); + orig_addr_offset = swiotlb_align_offset(dev, orig_addr); + if (tlb_offset < orig_addr_offset) { + dev_WARN_ONCE(dev, 1, + "Access before mapping start detected. orig offset %u, requested offset %u.\n", + orig_addr_offset, tlb_offset); + return; + } + + tlb_offset -= orig_addr_offset; + if (tlb_offset > alloc_size) { + dev_WARN_ONCE(dev, 1, + "Buffer overflow detected. Allocation size: %zu. Mapping size: %zu+%u.\n", + alloc_size, size, tlb_offset); + return; + } orig_addr += tlb_offset; alloc_size -= tlb_offset; @@ -426,10 +458,10 @@ static unsigned int wrap_index(struct io_tlb_mem *mem, unsigned int index) * Find a suitable number of IO TLB entries size that will fit this request and * allocate a buffer from that IO TLB pool. */ -static int find_slots(struct device *dev, phys_addr_t orig_addr, - size_t alloc_size) +static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, + size_t alloc_size) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned long boundary_mask = dma_get_seg_boundary(dev); dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(dev, mem->start) & boundary_mask; @@ -438,6 +470,7 @@ static int find_slots(struct device *dev, phys_addr_t orig_addr, dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1); unsigned int nslots = nr_slots(alloc_size), stride; unsigned int index, wrap, count = 0, i; + unsigned int offset = swiotlb_align_offset(dev, orig_addr); unsigned long flags; BUG_ON(!nslots); @@ -457,8 +490,9 @@ static int find_slots(struct device *dev, phys_addr_t orig_addr, index = wrap = wrap_index(mem, ALIGN(mem->index, stride)); do { - if ((slot_addr(tbl_dma_addr, index) & iotlb_align_mask) != - (orig_addr & iotlb_align_mask)) { + if (orig_addr && + (slot_addr(tbl_dma_addr, index) & iotlb_align_mask) != + (orig_addr & iotlb_align_mask)) { index = wrap_index(mem, index + 1); continue; } @@ -482,8 +516,11 @@ not_found: return -1; found: - for (i = index; i < index + nslots; i++) + for (i = index; i < index + nslots; i++) { mem->slots[i].list = 0; + mem->slots[i].alloc_size = + alloc_size - (offset + ((i - index) << IO_TLB_SHIFT)); + } for (i = index - 1; io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && mem->slots[i].list; i--) @@ -506,7 +543,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, size_t mapping_size, size_t alloc_size, enum dma_data_direction dir, unsigned long attrs) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned int offset = swiotlb_align_offset(dev, orig_addr); unsigned int i; int index; @@ -524,7 +561,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, return (phys_addr_t)DMA_MAPPING_ERROR; } - index = find_slots(dev, orig_addr, alloc_size + offset); + index = swiotlb_find_slots(dev, orig_addr, alloc_size + offset); if (index == -1) { if (!(attrs & DMA_ATTR_NO_WARN)) dev_warn_ratelimited(dev, @@ -538,11 +575,8 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, * This is needed when we sync the memory. Then we sync the buffer if * needed. */ - for (i = 0; i < nr_slots(alloc_size + offset); i++) { + for (i = 0; i < nr_slots(alloc_size + offset); i++) mem->slots[index + i].orig_addr = slot_addr(orig_addr, i); - mem->slots[index + i].alloc_size = - alloc_size - (i << IO_TLB_SHIFT); - } tlb_addr = slot_addr(mem->start, index) + offset; if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) @@ -550,28 +584,16 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, return tlb_addr; } -/* - * tlb_addr is the physical address of the bounce buffer to unmap. - */ -void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, - size_t mapping_size, enum dma_data_direction dir, - unsigned long attrs) +static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned long flags; - unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr); + unsigned int offset = swiotlb_align_offset(dev, tlb_addr); int index = (tlb_addr - offset - mem->start) >> IO_TLB_SHIFT; int nslots = nr_slots(mem->slots[index].alloc_size + offset); int count, i; /* - * First, sync the memory before unmapping the entry - */ - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) - swiotlb_bounce(hwdev, tlb_addr, mapping_size, DMA_FROM_DEVICE); - - /* * Return the buffer to the free list by setting the corresponding * entries to indicate the number of contiguous entries available. * While returning the entries to the free list, we merge the entries @@ -605,6 +627,23 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, spin_unlock_irqrestore(&mem->lock, flags); } +/* + * tlb_addr is the physical address of the bounce buffer to unmap. + */ +void swiotlb_tbl_unmap_single(struct device *dev, phys_addr_t tlb_addr, + size_t mapping_size, enum dma_data_direction dir, + unsigned long attrs) +{ + /* + * First, sync the memory before unmapping the entry + */ + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) + swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_FROM_DEVICE); + + swiotlb_release_slots(dev, tlb_addr); +} + void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) { @@ -662,26 +701,155 @@ size_t swiotlb_max_mapping_size(struct device *dev) return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE; } -bool is_swiotlb_active(void) +bool is_swiotlb_active(struct device *dev) { - return io_tlb_default_mem != NULL; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + + return mem && mem->nslabs; } EXPORT_SYMBOL_GPL(is_swiotlb_active); #ifdef CONFIG_DEBUG_FS +static struct dentry *debugfs_dir; -static int __init swiotlb_create_debugfs(void) +static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem) { - struct io_tlb_mem *mem = io_tlb_default_mem; - - if (!mem) - return 0; - mem->debugfs = debugfs_create_dir("swiotlb", NULL); debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs); debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &mem->used); +} + +static int __init swiotlb_create_default_debugfs(void) +{ + struct io_tlb_mem *mem = &io_tlb_default_mem; + + debugfs_dir = debugfs_create_dir("swiotlb", NULL); + if (mem->nslabs) { + mem->debugfs = debugfs_dir; + swiotlb_create_debugfs_files(mem); + } return 0; } -late_initcall(swiotlb_create_debugfs); +late_initcall(swiotlb_create_default_debugfs); + +#endif +#ifdef CONFIG_DMA_RESTRICTED_POOL + +#ifdef CONFIG_DEBUG_FS +static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem) +{ + struct io_tlb_mem *mem = rmem->priv; + + mem->debugfs = debugfs_create_dir(rmem->name, debugfs_dir); + swiotlb_create_debugfs_files(mem); +} +#else +static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem) +{ +} #endif + +struct page *swiotlb_alloc(struct device *dev, size_t size) +{ + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + phys_addr_t tlb_addr; + int index; + + if (!mem) + return NULL; + + index = swiotlb_find_slots(dev, 0, size); + if (index == -1) + return NULL; + + tlb_addr = slot_addr(mem->start, index); + + return pfn_to_page(PFN_DOWN(tlb_addr)); +} + +bool swiotlb_free(struct device *dev, struct page *page, size_t size) +{ + phys_addr_t tlb_addr = page_to_phys(page); + + if (!is_swiotlb_buffer(dev, tlb_addr)) + return false; + + swiotlb_release_slots(dev, tlb_addr); + + return true; +} + +static int rmem_swiotlb_device_init(struct reserved_mem *rmem, + struct device *dev) +{ + struct io_tlb_mem *mem = rmem->priv; + unsigned long nslabs = rmem->size >> IO_TLB_SHIFT; + + /* + * Since multiple devices can share the same pool, the private data, + * io_tlb_mem struct, will be initialized by the first device attached + * to it. + */ + if (!mem) { + mem = kzalloc(sizeof(*mem), GFP_KERNEL); + if (!mem) + return -ENOMEM; + + mem->slots = kzalloc(array_size(sizeof(*mem->slots), nslabs), + GFP_KERNEL); + if (!mem->slots) { + kfree(mem); + return -ENOMEM; + } + + set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), + rmem->size >> PAGE_SHIFT); + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); + mem->force_bounce = true; + mem->for_alloc = true; + + rmem->priv = mem; + + rmem_swiotlb_debugfs_init(rmem); + } + + dev->dma_io_tlb_mem = mem; + + return 0; +} + +static void rmem_swiotlb_device_release(struct reserved_mem *rmem, + struct device *dev) +{ + dev->dma_io_tlb_mem = &io_tlb_default_mem; +} + +static const struct reserved_mem_ops rmem_swiotlb_ops = { + .device_init = rmem_swiotlb_device_init, + .device_release = rmem_swiotlb_device_release, +}; + +static int __init rmem_swiotlb_setup(struct reserved_mem *rmem) +{ + unsigned long node = rmem->fdt_node; + + if (of_get_flat_dt_prop(node, "reusable", NULL) || + of_get_flat_dt_prop(node, "linux,cma-default", NULL) || + of_get_flat_dt_prop(node, "linux,dma-default", NULL) || + of_get_flat_dt_prop(node, "no-map", NULL)) + return -EINVAL; + + if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { + pr_err("Restricted DMA pool must be accessible within the linear mapping."); + return -EINVAL; + } + + rmem->ops = &rmem_swiotlb_ops; + pr_info("Reserved memory: created restricted DMA pool at %pa, size %ld MiB\n", + &rmem->base, (unsigned long)rmem->size / SZ_1M); + return 0; +} + +RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup); +#endif /* CONFIG_DMA_RESTRICTED_POOL */ diff --git a/kernel/entry/common.c b/kernel/entry/common.c index bf16395b9e13..d5a61d565ad5 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -171,10 +171,8 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) handle_signal_work(regs, ti_work); - if (ti_work & _TIF_NOTIFY_RESUME) { + if (ti_work & _TIF_NOTIFY_RESUME) tracehook_notify_resume(regs); - rseq_handle_notify_resume(NULL, regs); - } /* Architecture specific TIF work */ arch_exit_to_user_mode_work(regs, ti_work); diff --git a/kernel/events/core.c b/kernel/events/core.c index 0e90a5084f18..a89b01b7e59a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3707,6 +3707,29 @@ static noinline int visit_groups_merge(struct perf_cpu_context *cpuctx, return 0; } +static inline bool event_update_userpage(struct perf_event *event) +{ + if (likely(!atomic_read(&event->mmap_count))) + return false; + + perf_event_update_time(event); + perf_set_shadow_time(event, event->ctx); + perf_event_update_userpage(event); + + return true; +} + +static inline void group_update_userpage(struct perf_event *group_event) +{ + struct perf_event *event; + + if (!event_update_userpage(group_event)) + return; + + for_each_sibling_event(event, group_event) + event_update_userpage(event); +} + static int merge_sched_in(struct perf_event *event, void *data) { struct perf_event_context *ctx = event->ctx; @@ -3725,14 +3748,15 @@ static int merge_sched_in(struct perf_event *event, void *data) } if (event->state == PERF_EVENT_STATE_INACTIVE) { + *can_add_hw = 0; if (event->attr.pinned) { perf_cgroup_event_disable(event, ctx); perf_event_set_state(event, PERF_EVENT_STATE_ERROR); + } else { + ctx->rotate_necessary = 1; + perf_mux_hrtimer_restart(cpuctx); + group_update_userpage(event); } - - *can_add_hw = 0; - ctx->rotate_necessary = 1; - perf_mux_hrtimer_restart(cpuctx); } return 0; @@ -4697,7 +4721,6 @@ errout: } static void perf_event_free_filter(struct perf_event *event); -static void perf_event_free_bpf_prog(struct perf_event *event); static void free_event_rcu(struct rcu_head *head) { @@ -5574,7 +5597,6 @@ static inline int perf_fget_light(int fd, struct fd *p) static int perf_event_set_output(struct perf_event *event, struct perf_event *output_event); static int perf_event_set_filter(struct perf_event *event, void __user *arg); -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr); @@ -5637,7 +5659,22 @@ static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned lon return perf_event_set_filter(event, (void __user *)arg); case PERF_EVENT_IOC_SET_BPF: - return perf_event_set_bpf_prog(event, arg); + { + struct bpf_prog *prog; + int err; + + prog = bpf_prog_get(arg); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + err = perf_event_set_bpf_prog(event, prog, 0); + if (err) { + bpf_prog_put(prog); + return err; + } + + return 0; + } case PERF_EVENT_IOC_PAUSE_OUTPUT: { struct perf_buffer *rb; @@ -6311,6 +6348,8 @@ accounting: ring_buffer_attach(event, rb); + perf_event_update_time(event); + perf_set_shadow_time(event, event->ctx); perf_event_init_userpage(event); perf_event_update_userpage(event); } else { @@ -8307,8 +8346,6 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) else flags = MAP_PRIVATE; - if (vma->vm_flags & VM_DENYWRITE) - flags |= MAP_DENYWRITE; if (vma->vm_flags & VM_LOCKED) flags |= MAP_LOCKED; if (is_vm_hugetlb_page(vma)) @@ -9937,13 +9974,16 @@ static void bpf_overflow_handler(struct perf_event *event, .data = data, .event = event, }; + struct bpf_prog *prog; int ret = 0; ctx.regs = perf_arch_bpf_user_pt_regs(regs); if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) goto out; rcu_read_lock(); - ret = BPF_PROG_RUN(event->prog, &ctx); + prog = READ_ONCE(event->prog); + if (prog) + ret = bpf_prog_run(prog, &ctx); rcu_read_unlock(); out: __this_cpu_dec(bpf_prog_active); @@ -9953,10 +9993,10 @@ out: event->orig_overflow_handler(event, data, regs); } -static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_handler(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) { - struct bpf_prog *prog; - if (event->overflow_handler_context) /* hw breakpoint or kernel counter */ return -EINVAL; @@ -9964,9 +10004,8 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) if (event->prog) return -EEXIST; - prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT); - if (IS_ERR(prog)) - return PTR_ERR(prog); + if (prog->type != BPF_PROG_TYPE_PERF_EVENT) + return -EINVAL; if (event->attr.precise_ip && prog->call_get_stack && @@ -9982,11 +10021,11 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) * attached to perf_sample_data, do not allow attaching BPF * program that calls bpf_get_[stack|stackid]. */ - bpf_prog_put(prog); return -EPROTO; } event->prog = prog; + event->bpf_cookie = bpf_cookie; event->orig_overflow_handler = READ_ONCE(event->overflow_handler); WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); return 0; @@ -10004,7 +10043,9 @@ static void perf_event_free_bpf_handler(struct perf_event *event) bpf_prog_put(prog); } #else -static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_handler(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) { return -EOPNOTSUPP; } @@ -10032,14 +10073,13 @@ static inline bool perf_event_is_tracing(struct perf_event *event) return false; } -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) +int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, + u64 bpf_cookie) { bool is_kprobe, is_tracepoint, is_syscall_tp; - struct bpf_prog *prog; - int ret; if (!perf_event_is_tracing(event)) - return perf_event_set_bpf_handler(event, prog_fd); + return perf_event_set_bpf_handler(event, prog, bpf_cookie); is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; @@ -10048,41 +10088,27 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL; - prog = bpf_prog_get(prog_fd); - if (IS_ERR(prog)) - return PTR_ERR(prog); - if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || - (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) { - /* valid fd, but invalid bpf program type */ - bpf_prog_put(prog); + (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL; - } /* Kprobe override only works for kprobes, not uprobes. */ if (prog->kprobe_override && - !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) { - bpf_prog_put(prog); + !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) return -EINVAL; - } if (is_tracepoint || is_syscall_tp) { int off = trace_event_get_offsets(event->tp_event); - if (prog->aux->max_ctx_offset > off) { - bpf_prog_put(prog); + if (prog->aux->max_ctx_offset > off) return -EACCES; - } } - ret = perf_event_attach_bpf_prog(event, prog); - if (ret) - bpf_prog_put(prog); - return ret; + return perf_event_attach_bpf_prog(event, prog, bpf_cookie); } -static void perf_event_free_bpf_prog(struct perf_event *event) +void perf_event_free_bpf_prog(struct perf_event *event) { if (!perf_event_is_tracing(event)) { perf_event_free_bpf_handler(event); @@ -10101,12 +10127,13 @@ static void perf_event_free_filter(struct perf_event *event) { } -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) +int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, + u64 bpf_cookie) { return -ENOENT; } -static void perf_event_free_bpf_prog(struct perf_event *event) +void perf_event_free_bpf_prog(struct perf_event *event) { } #endif /* CONFIG_EVENT_TRACING */ @@ -10222,7 +10249,7 @@ static void perf_event_addr_filters_apply(struct perf_event *event) return; if (ifh->nr_file_filters) { - mm = get_task_mm(event->ctx->task); + mm = get_task_mm(task); if (!mm) goto restart; diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index af24dc3febbe..6357c3580d07 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -167,7 +167,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, addr + PAGE_SIZE); if (new_page) { - err = mem_cgroup_charge(new_page, vma->vm_mm, GFP_KERNEL); + err = mem_cgroup_charge(page_folio(new_page), vma->vm_mm, + GFP_KERNEL); if (err) return err; } diff --git a/kernel/exit.c b/kernel/exit.c index 9a89e7f36acb..a53863dafb3d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -48,7 +48,6 @@ #include <linux/pipe_fs_i.h> #include <linux/audit.h> /* for audit_free() */ #include <linux/resource.h> -#include <linux/blkdev.h> #include <linux/task_io_accounting_ops.h> #include <linux/tracehook.h> #include <linux/fs_struct.h> @@ -777,7 +776,7 @@ void __noreturn do_exit(long code) schedule(); } - io_uring_files_cancel(tsk->files); + io_uring_files_cancel(); exit_signals(tsk); /* sets PF_EXITING */ /* sync mm's RSS info before statistics gathering */ diff --git a/kernel/fork.c b/kernel/fork.c index bc94b2cc5995..67679e3933f2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -76,7 +76,6 @@ #include <linux/taskstats_kern.h> #include <linux/random.h> #include <linux/tty.h> -#include <linux/blkdev.h> #include <linux/fs_struct.h> #include <linux/magic.h> #include <linux/perf_event.h> @@ -446,6 +445,7 @@ void put_task_stack(struct task_struct *tsk) void free_task(struct task_struct *tsk) { + release_user_cpus_ptr(tsk); scs_release(tsk); #ifndef CONFIG_THREAD_INFO_IN_TASK @@ -470,6 +470,20 @@ void free_task(struct task_struct *tsk) } EXPORT_SYMBOL(free_task); +static void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm) +{ + struct file *exe_file; + + exe_file = get_mm_exe_file(oldmm); + RCU_INIT_POINTER(mm->exe_file, exe_file); + /* + * We depend on the oldmm having properly denied write access to the + * exe_file already. + */ + if (exe_file && deny_write_access(exe_file)) + pr_warn_once("deny_write_access() failed in %s\n", __func__); +} + #ifdef CONFIG_MMU static __latent_entropy int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) @@ -493,7 +507,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, mmap_write_lock_nested(mm, SINGLE_DEPTH_NESTING); /* No ordering required: file already has been exposed. */ - RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm)); + dup_mm_exe_file(mm, oldmm); mm->total_vm = oldmm->total_vm; mm->data_vm = oldmm->data_vm; @@ -556,12 +570,9 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT); file = tmp->vm_file; if (file) { - struct inode *inode = file_inode(file); struct address_space *mapping = file->f_mapping; get_file(file); - if (tmp->vm_flags & VM_DENYWRITE) - put_write_access(inode); i_mmap_lock_write(mapping); if (tmp->vm_flags & VM_SHARED) mapping_allow_writable(mapping); @@ -639,7 +650,7 @@ static inline void mm_free_pgd(struct mm_struct *mm) static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) { mmap_write_lock(oldmm); - RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm)); + dup_mm_exe_file(mm, oldmm); mmap_write_unlock(oldmm); return 0; } @@ -828,10 +839,10 @@ void __init fork_init(void) for (i = 0; i < MAX_PER_NAMESPACE_UCOUNTS; i++) init_user_ns.ucount_max[i] = max_threads/2; - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_NPROC, task_rlimit(&init_task, RLIMIT_NPROC)); - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_MSGQUEUE, task_rlimit(&init_task, RLIMIT_MSGQUEUE)); - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_SIGPENDING, task_rlimit(&init_task, RLIMIT_SIGPENDING)); - set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_MEMLOCK, task_rlimit(&init_task, RLIMIT_MEMLOCK)); + set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_NPROC, RLIM_INFINITY); + set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_MSGQUEUE, RLIM_INFINITY); + set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_SIGPENDING, RLIM_INFINITY); + set_rlimit_ucount_max(&init_user_ns, UCOUNT_RLIMIT_MEMLOCK, RLIM_INFINITY); #ifdef CONFIG_VMAP_STACK cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "fork:vm_stack_cache", @@ -924,6 +935,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) #endif if (orig->cpus_ptr == &orig->cpus_mask) tsk->cpus_ptr = &tsk->cpus_mask; + dup_user_cpus_ptr(tsk, orig, node); /* * One for the user space visible state that goes away when reaped. @@ -1050,6 +1062,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm->pmd_huge_pte = NULL; #endif mm_init_uprobes_state(mm); + hugetlb_count_init(mm); if (current->mm) { mm->flags = current->mm->flags & MMF_INIT_MASK; @@ -1148,11 +1161,11 @@ void mmput_async(struct mm_struct *mm) * * Main users are mmput() and sys_execve(). Callers prevent concurrent * invocations: in mmput() nobody alive left, in execve task is single - * threaded. sys_prctl(PR_SET_MM_MAP/EXE_FILE) also needs to set the - * mm->exe_file, but does so without using set_mm_exe_file() in order - * to avoid the need for any locks. + * threaded. + * + * Can only fail if new_exe_file != NULL. */ -void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) +int set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) { struct file *old_exe_file; @@ -1163,11 +1176,73 @@ void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) */ old_exe_file = rcu_dereference_raw(mm->exe_file); - if (new_exe_file) + if (new_exe_file) { + /* + * We expect the caller (i.e., sys_execve) to already denied + * write access, so this is unlikely to fail. + */ + if (unlikely(deny_write_access(new_exe_file))) + return -EACCES; get_file(new_exe_file); + } rcu_assign_pointer(mm->exe_file, new_exe_file); - if (old_exe_file) + if (old_exe_file) { + allow_write_access(old_exe_file); fput(old_exe_file); + } + return 0; +} + +/** + * replace_mm_exe_file - replace a reference to the mm's executable file + * + * This changes mm's executable file (shown as symlink /proc/[pid]/exe), + * dealing with concurrent invocation and without grabbing the mmap lock in + * write mode. + * + * Main user is sys_prctl(PR_SET_MM_MAP/EXE_FILE). + */ +int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) +{ + struct vm_area_struct *vma; + struct file *old_exe_file; + int ret = 0; + + /* Forbid mm->exe_file change if old file still mapped. */ + old_exe_file = get_mm_exe_file(mm); + if (old_exe_file) { + mmap_read_lock(mm); + for (vma = mm->mmap; vma && !ret; vma = vma->vm_next) { + if (!vma->vm_file) + continue; + if (path_equal(&vma->vm_file->f_path, + &old_exe_file->f_path)) + ret = -EBUSY; + } + mmap_read_unlock(mm); + fput(old_exe_file); + if (ret) + return ret; + } + + /* set the new file, lockless */ + ret = deny_write_access(new_exe_file); + if (ret) + return -EACCES; + get_file(new_exe_file); + + old_exe_file = xchg(&mm->exe_file, new_exe_file); + if (old_exe_file) { + /* + * Don't race with dup_mmap() getting the file and disallowing + * write access while someone might open the file writable. + */ + mmap_read_lock(mm); + allow_write_access(old_exe_file); + fput(old_exe_file); + mmap_read_unlock(mm); + } + return 0; } /** @@ -1187,7 +1262,6 @@ struct file *get_mm_exe_file(struct mm_struct *mm) rcu_read_unlock(); return exe_file; } -EXPORT_SYMBOL(get_mm_exe_file); /** * get_task_exe_file - acquire a reference to the task's executable file @@ -1210,7 +1284,6 @@ struct file *get_task_exe_file(struct task_struct *task) task_unlock(task); return exe_file; } -EXPORT_SYMBOL(get_task_exe_file); /** * get_task_mm - acquire a reference to the task's mm @@ -2083,6 +2156,7 @@ static __latent_entropy struct task_struct *copy_process( #endif #ifdef CONFIG_BPF_SYSCALL RCU_INIT_POINTER(p->bpf_storage, NULL); + p->bpf_ctx = NULL; #endif /* Perform scheduler related setup. Assign this task to a CPU. */ diff --git a/kernel/futex.c b/kernel/futex.c index 2ecb07575055..c15ad276fd15 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -179,7 +179,7 @@ struct futex_pi_state { /* * The PI object: */ - struct rt_mutex pi_mutex; + struct rt_mutex_base pi_mutex; struct task_struct *owner; refcount_t refcount; @@ -197,6 +197,8 @@ struct futex_pi_state { * @rt_waiter: rt_waiter storage for use with requeue_pi * @requeue_pi_key: the requeue_pi target futex key * @bitset: bitset for the optional bitmasked wakeup + * @requeue_state: State field for futex_requeue_pi() + * @requeue_wait: RCU wait for futex_requeue_pi() (RT only) * * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so * we can wake only the relevant ones (hashed queues may be shared). @@ -219,12 +221,68 @@ struct futex_q { struct rt_mutex_waiter *rt_waiter; union futex_key *requeue_pi_key; u32 bitset; + atomic_t requeue_state; +#ifdef CONFIG_PREEMPT_RT + struct rcuwait requeue_wait; +#endif } __randomize_layout; +/* + * On PREEMPT_RT, the hash bucket lock is a 'sleeping' spinlock with an + * underlying rtmutex. The task which is about to be requeued could have + * just woken up (timeout, signal). After the wake up the task has to + * acquire hash bucket lock, which is held by the requeue code. As a task + * can only be blocked on _ONE_ rtmutex at a time, the proxy lock blocking + * and the hash bucket lock blocking would collide and corrupt state. + * + * On !PREEMPT_RT this is not a problem and everything could be serialized + * on hash bucket lock, but aside of having the benefit of common code, + * this allows to avoid doing the requeue when the task is already on the + * way out and taking the hash bucket lock of the original uaddr1 when the + * requeue has been completed. + * + * The following state transitions are valid: + * + * On the waiter side: + * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IGNORE + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT + * + * On the requeue side: + * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_INPROGRESS + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_DONE/LOCKED + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_NONE (requeue failed) + * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_DONE/LOCKED + * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_IGNORE (requeue failed) + * + * The requeue side ignores a waiter with state Q_REQUEUE_PI_IGNORE as this + * signals that the waiter is already on the way out. It also means that + * the waiter is still on the 'wait' futex, i.e. uaddr1. + * + * The waiter side signals early wakeup to the requeue side either through + * setting state to Q_REQUEUE_PI_IGNORE or to Q_REQUEUE_PI_WAIT depending + * on the current state. In case of Q_REQUEUE_PI_IGNORE it can immediately + * proceed to take the hash bucket lock of uaddr1. If it set state to WAIT, + * which means the wakeup is interleaving with a requeue in progress it has + * to wait for the requeue side to change the state. Either to DONE/LOCKED + * or to IGNORE. DONE/LOCKED means the waiter q is now on the uaddr2 futex + * and either blocked (DONE) or has acquired it (LOCKED). IGNORE is set by + * the requeue side when the requeue attempt failed via deadlock detection + * and therefore the waiter q is still on the uaddr1 futex. + */ +enum { + Q_REQUEUE_PI_NONE = 0, + Q_REQUEUE_PI_IGNORE, + Q_REQUEUE_PI_IN_PROGRESS, + Q_REQUEUE_PI_WAIT, + Q_REQUEUE_PI_DONE, + Q_REQUEUE_PI_LOCKED, +}; + static const struct futex_q futex_q_init = { /* list gets initialized in queue_me()*/ - .key = FUTEX_KEY_INIT, - .bitset = FUTEX_BITSET_MATCH_ANY + .key = FUTEX_KEY_INIT, + .bitset = FUTEX_BITSET_MATCH_ANY, + .requeue_state = ATOMIC_INIT(Q_REQUEUE_PI_NONE), }; /* @@ -1205,6 +1263,36 @@ static int handle_exit_race(u32 __user *uaddr, u32 uval, return -ESRCH; } +static void __attach_to_pi_owner(struct task_struct *p, union futex_key *key, + struct futex_pi_state **ps) +{ + /* + * No existing pi state. First waiter. [2] + * + * This creates pi_state, we have hb->lock held, this means nothing can + * observe this state, wait_lock is irrelevant. + */ + struct futex_pi_state *pi_state = alloc_pi_state(); + + /* + * Initialize the pi_mutex in locked state and make @p + * the owner of it: + */ + rt_mutex_init_proxy_locked(&pi_state->pi_mutex, p); + + /* Store the key for possible exit cleanups: */ + pi_state->key = *key; + + WARN_ON(!list_empty(&pi_state->list)); + list_add(&pi_state->list, &p->pi_state_list); + /* + * Assignment without holding pi_state->pi_mutex.wait_lock is safe + * because there is no concurrency as the object is not published yet. + */ + pi_state->owner = p; + + *ps = pi_state; +} /* * Lookup the task for the TID provided from user space and attach to * it after doing proper sanity checks. @@ -1214,7 +1302,6 @@ static int attach_to_pi_owner(u32 __user *uaddr, u32 uval, union futex_key *key, struct task_struct **exiting) { pid_t pid = uval & FUTEX_TID_MASK; - struct futex_pi_state *pi_state; struct task_struct *p; /* @@ -1266,60 +1353,14 @@ static int attach_to_pi_owner(u32 __user *uaddr, u32 uval, union futex_key *key, return ret; } - /* - * No existing pi state. First waiter. [2] - * - * This creates pi_state, we have hb->lock held, this means nothing can - * observe this state, wait_lock is irrelevant. - */ - pi_state = alloc_pi_state(); - - /* - * Initialize the pi_mutex in locked state and make @p - * the owner of it: - */ - rt_mutex_init_proxy_locked(&pi_state->pi_mutex, p); - - /* Store the key for possible exit cleanups: */ - pi_state->key = *key; - - WARN_ON(!list_empty(&pi_state->list)); - list_add(&pi_state->list, &p->pi_state_list); - /* - * Assignment without holding pi_state->pi_mutex.wait_lock is safe - * because there is no concurrency as the object is not published yet. - */ - pi_state->owner = p; + __attach_to_pi_owner(p, key, ps); raw_spin_unlock_irq(&p->pi_lock); put_task_struct(p); - *ps = pi_state; - return 0; } -static int lookup_pi_state(u32 __user *uaddr, u32 uval, - struct futex_hash_bucket *hb, - union futex_key *key, struct futex_pi_state **ps, - struct task_struct **exiting) -{ - struct futex_q *top_waiter = futex_top_waiter(hb, key); - - /* - * If there is a waiter on that futex, validate it and - * attach to the pi_state when the validation succeeds. - */ - if (top_waiter) - return attach_to_pi_state(uaddr, uval, top_waiter->pi_state, ps); - - /* - * We are the first waiter - try to look up the owner based on - * @uval and attach to it. - */ - return attach_to_pi_owner(uaddr, uval, key, ps, exiting); -} - static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval) { int err; @@ -1354,7 +1395,7 @@ static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval) * - 1 - acquired the lock; * - <0 - error * - * The hb->lock and futex_key refs shall be held by the caller. + * The hb->lock must be held by the caller. * * @exiting is only set when the return value is -EBUSY. If so, this holds * a refcount on the exiting task on return and the caller needs to drop it @@ -1417,8 +1458,26 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb, newval |= FUTEX_WAITERS; ret = lock_pi_update_atomic(uaddr, uval, newval); - /* If the take over worked, return 1 */ - return ret < 0 ? ret : 1; + if (ret) + return ret; + + /* + * If the waiter bit was requested the caller also needs PI + * state attached to the new owner of the user space futex. + * + * @task is guaranteed to be alive and it cannot be exiting + * because it is either sleeping or waiting in + * futex_requeue_pi_wakeup_sync(). + * + * No need to do the full attach_to_pi_owner() exercise + * because @task is known and valid. + */ + if (set_waiters) { + raw_spin_lock_irq(&task->pi_lock); + __attach_to_pi_owner(task, key, ps); + raw_spin_unlock_irq(&task->pi_lock); + } + return 1; } /* @@ -1493,11 +1552,11 @@ static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q) */ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_state) { - u32 curval, newval; struct rt_mutex_waiter *top_waiter; struct task_struct *new_owner; bool postunlock = false; - DEFINE_WAKE_Q(wake_q); + DEFINE_RT_WAKE_Q(wqh); + u32 curval, newval; int ret = 0; top_waiter = rt_mutex_top_waiter(&pi_state->pi_mutex); @@ -1549,14 +1608,14 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ * not fail. */ pi_state_update_owner(pi_state, new_owner); - postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q); + postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wqh); } out_unlock: raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); if (postunlock) - rt_mutex_postunlock(&wake_q); + rt_mutex_postunlock(&wqh); return ret; } @@ -1793,6 +1852,108 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1, q->key = *key2; } +static inline bool futex_requeue_pi_prepare(struct futex_q *q, + struct futex_pi_state *pi_state) +{ + int old, new; + + /* + * Set state to Q_REQUEUE_PI_IN_PROGRESS unless an early wakeup has + * already set Q_REQUEUE_PI_IGNORE to signal that requeue should + * ignore the waiter. + */ + old = atomic_read_acquire(&q->requeue_state); + do { + if (old == Q_REQUEUE_PI_IGNORE) + return false; + + /* + * futex_proxy_trylock_atomic() might have set it to + * IN_PROGRESS and a interleaved early wake to WAIT. + * + * It was considered to have an extra state for that + * trylock, but that would just add more conditionals + * all over the place for a dubious value. + */ + if (old != Q_REQUEUE_PI_NONE) + break; + + new = Q_REQUEUE_PI_IN_PROGRESS; + } while (!atomic_try_cmpxchg(&q->requeue_state, &old, new)); + + q->pi_state = pi_state; + return true; +} + +static inline void futex_requeue_pi_complete(struct futex_q *q, int locked) +{ + int old, new; + + old = atomic_read_acquire(&q->requeue_state); + do { + if (old == Q_REQUEUE_PI_IGNORE) + return; + + if (locked >= 0) { + /* Requeue succeeded. Set DONE or LOCKED */ + WARN_ON_ONCE(old != Q_REQUEUE_PI_IN_PROGRESS && + old != Q_REQUEUE_PI_WAIT); + new = Q_REQUEUE_PI_DONE + locked; + } else if (old == Q_REQUEUE_PI_IN_PROGRESS) { + /* Deadlock, no early wakeup interleave */ + new = Q_REQUEUE_PI_NONE; + } else { + /* Deadlock, early wakeup interleave. */ + WARN_ON_ONCE(old != Q_REQUEUE_PI_WAIT); + new = Q_REQUEUE_PI_IGNORE; + } + } while (!atomic_try_cmpxchg(&q->requeue_state, &old, new)); + +#ifdef CONFIG_PREEMPT_RT + /* If the waiter interleaved with the requeue let it know */ + if (unlikely(old == Q_REQUEUE_PI_WAIT)) + rcuwait_wake_up(&q->requeue_wait); +#endif +} + +static inline int futex_requeue_pi_wakeup_sync(struct futex_q *q) +{ + int old, new; + + old = atomic_read_acquire(&q->requeue_state); + do { + /* Is requeue done already? */ + if (old >= Q_REQUEUE_PI_DONE) + return old; + + /* + * If not done, then tell the requeue code to either ignore + * the waiter or to wake it up once the requeue is done. + */ + new = Q_REQUEUE_PI_WAIT; + if (old == Q_REQUEUE_PI_NONE) + new = Q_REQUEUE_PI_IGNORE; + } while (!atomic_try_cmpxchg(&q->requeue_state, &old, new)); + + /* If the requeue was in progress, wait for it to complete */ + if (old == Q_REQUEUE_PI_IN_PROGRESS) { +#ifdef CONFIG_PREEMPT_RT + rcuwait_wait_event(&q->requeue_wait, + atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT, + TASK_UNINTERRUPTIBLE); +#else + (void)atomic_cond_read_relaxed(&q->requeue_state, VAL != Q_REQUEUE_PI_WAIT); +#endif + } + + /* + * Requeue is now either prohibited or complete. Reread state + * because during the wait above it might have changed. Nothing + * will modify q->requeue_state after this point. + */ + return atomic_read(&q->requeue_state); +} + /** * requeue_pi_wake_futex() - Wake a task that acquired the lock during requeue * @q: the futex_q @@ -1800,12 +1961,26 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1, * @hb: the hash_bucket of the requeue target futex * * During futex_requeue, with requeue_pi=1, it is possible to acquire the - * target futex if it is uncontended or via a lock steal. Set the futex_q key - * to the requeue target futex so the waiter can detect the wakeup on the right - * futex, but remove it from the hb and NULL the rt_waiter so it can detect - * atomic lock acquisition. Set the q->lock_ptr to the requeue target hb->lock - * to protect access to the pi_state to fixup the owner later. Must be called - * with both q->lock_ptr and hb->lock held. + * target futex if it is uncontended or via a lock steal. + * + * 1) Set @q::key to the requeue target futex key so the waiter can detect + * the wakeup on the right futex. + * + * 2) Dequeue @q from the hash bucket. + * + * 3) Set @q::rt_waiter to NULL so the woken up task can detect atomic lock + * acquisition. + * + * 4) Set the q->lock_ptr to the requeue target hb->lock for the case that + * the waiter has to fixup the pi state. + * + * 5) Complete the requeue state so the waiter can make progress. After + * this point the waiter task can return from the syscall immediately in + * case that the pi state does not have to be fixed up. + * + * 6) Wake the waiter task. + * + * Must be called with both q->lock_ptr and hb->lock held. */ static inline void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key, @@ -1820,6 +1995,8 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key, q->lock_ptr = &hb->lock; + /* Signal locked state to the waiter */ + futex_requeue_pi_complete(q, 1); wake_up_state(q->task, TASK_NORMAL); } @@ -1857,7 +2034,7 @@ futex_proxy_trylock_atomic(u32 __user *pifutex, struct futex_hash_bucket *hb1, { struct futex_q *top_waiter = NULL; u32 curval; - int ret, vpid; + int ret; if (get_futex_value_locked(&curval, pifutex)) return -EFAULT; @@ -1879,21 +2056,52 @@ futex_proxy_trylock_atomic(u32 __user *pifutex, struct futex_hash_bucket *hb1, if (!top_waiter) return 0; + /* + * Ensure that this is a waiter sitting in futex_wait_requeue_pi() + * and waiting on the 'waitqueue' futex which is always !PI. + */ + if (!top_waiter->rt_waiter || top_waiter->pi_state) + return -EINVAL; + /* Ensure we requeue to the expected futex. */ if (!match_futex(top_waiter->requeue_pi_key, key2)) return -EINVAL; + /* Ensure that this does not race against an early wakeup */ + if (!futex_requeue_pi_prepare(top_waiter, NULL)) + return -EAGAIN; + /* - * Try to take the lock for top_waiter. Set the FUTEX_WAITERS bit in - * the contended case or if set_waiters is 1. The pi_state is returned - * in ps in contended cases. + * Try to take the lock for top_waiter and set the FUTEX_WAITERS bit + * in the contended case or if @set_waiters is true. + * + * In the contended case PI state is attached to the lock owner. If + * the user space lock can be acquired then PI state is attached to + * the new owner (@top_waiter->task) when @set_waiters is true. */ - vpid = task_pid_vnr(top_waiter->task); ret = futex_lock_pi_atomic(pifutex, hb2, key2, ps, top_waiter->task, exiting, set_waiters); if (ret == 1) { + /* + * Lock was acquired in user space and PI state was + * attached to @top_waiter->task. That means state is fully + * consistent and the waiter can return to user space + * immediately after the wakeup. + */ requeue_pi_wake_futex(top_waiter, key2, hb2); - return vpid; + } else if (ret < 0) { + /* Rewind top_waiter::requeue_state */ + futex_requeue_pi_complete(top_waiter, ret); + } else { + /* + * futex_lock_pi_atomic() did not acquire the user space + * futex, but managed to establish the proxy lock and pi + * state. top_waiter::requeue_state cannot be fixed up here + * because the waiter is not enqueued on the rtmutex + * yet. This is handled at the callsite depending on the + * result of rt_mutex_start_proxy_lock() which is + * guaranteed to be reached with this function returning 0. + */ } return ret; } @@ -1948,23 +2156,35 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, return -EINVAL; /* + * futex_requeue() allows the caller to define the number + * of waiters to wake up via the @nr_wake argument. With + * REQUEUE_PI, waking up more than one waiter is creating + * more problems than it solves. Waking up a waiter makes + * only sense if the PI futex @uaddr2 is uncontended as + * this allows the requeue code to acquire the futex + * @uaddr2 before waking the waiter. The waiter can then + * return to user space without further action. A secondary + * wakeup would just make the futex_wait_requeue_pi() + * handling more complex, because that code would have to + * look up pi_state and do more or less all the handling + * which the requeue code has to do for the to be requeued + * waiters. So restrict the number of waiters to wake to + * one, and only wake it up when the PI futex is + * uncontended. Otherwise requeue it and let the unlock of + * the PI futex handle the wakeup. + * + * All REQUEUE_PI users, e.g. pthread_cond_signal() and + * pthread_cond_broadcast() must use nr_wake=1. + */ + if (nr_wake != 1) + return -EINVAL; + + /* * requeue_pi requires a pi_state, try to allocate it now * without any locks in case it fails. */ if (refill_pi_state_cache()) return -ENOMEM; - /* - * requeue_pi must wake as many tasks as it can, up to nr_wake - * + nr_requeue, since it acquires the rt_mutex prior to - * returning to userspace, so as to not leave the rt_mutex with - * waiters and no owner. However, second and third wake-ups - * cannot be predicted as they involve race conditions with the - * first wake and a fault while looking up the pi_state. Both - * pthread_cond_signal() and pthread_cond_broadcast() should - * use nr_wake=1. - */ - if (nr_wake != 1) - return -EINVAL; } retry: @@ -2014,7 +2234,7 @@ retry_private: } } - if (requeue_pi && (task_count - nr_wake < nr_requeue)) { + if (requeue_pi) { struct task_struct *exiting = NULL; /* @@ -2022,45 +2242,65 @@ retry_private: * intend to requeue waiters, force setting the FUTEX_WAITERS * bit. We force this here where we are able to easily handle * faults rather in the requeue loop below. + * + * Updates topwaiter::requeue_state if a top waiter exists. */ ret = futex_proxy_trylock_atomic(uaddr2, hb1, hb2, &key1, &key2, &pi_state, &exiting, nr_requeue); /* - * At this point the top_waiter has either taken uaddr2 or is - * waiting on it. If the former, then the pi_state will not - * exist yet, look it up one more time to ensure we have a - * reference to it. If the lock was taken, ret contains the - * vpid of the top waiter task. - * If the lock was not taken, we have pi_state and an initial - * refcount on it. In case of an error we have nothing. + * At this point the top_waiter has either taken uaddr2 or + * is waiting on it. In both cases pi_state has been + * established and an initial refcount on it. In case of an + * error there's nothing. + * + * The top waiter's requeue_state is up to date: + * + * - If the lock was acquired atomically (ret == 1), then + * the state is Q_REQUEUE_PI_LOCKED. + * + * The top waiter has been dequeued and woken up and can + * return to user space immediately. The kernel/user + * space state is consistent. In case that there must be + * more waiters requeued the WAITERS bit in the user + * space futex is set so the top waiter task has to go + * into the syscall slowpath to unlock the futex. This + * will block until this requeue operation has been + * completed and the hash bucket locks have been + * dropped. + * + * - If the trylock failed with an error (ret < 0) then + * the state is either Q_REQUEUE_PI_NONE, i.e. "nothing + * happened", or Q_REQUEUE_PI_IGNORE when there was an + * interleaved early wakeup. + * + * - If the trylock did not succeed (ret == 0) then the + * state is either Q_REQUEUE_PI_IN_PROGRESS or + * Q_REQUEUE_PI_WAIT if an early wakeup interleaved. + * This will be cleaned up in the loop below, which + * cannot fail because futex_proxy_trylock_atomic() did + * the same sanity checks for requeue_pi as the loop + * below does. */ - if (ret > 0) { - WARN_ON(pi_state); - task_count++; - /* - * If we acquired the lock, then the user space value - * of uaddr2 should be vpid. It cannot be changed by - * the top waiter as it is blocked on hb2 lock if it - * tries to do so. If something fiddled with it behind - * our back the pi state lookup might unearth it. So - * we rather use the known value than rereading and - * handing potential crap to lookup_pi_state. - * - * If that call succeeds then we have pi_state and an - * initial refcount on it. - */ - ret = lookup_pi_state(uaddr2, ret, hb2, &key2, - &pi_state, &exiting); - } - switch (ret) { case 0: /* We hold a reference on the pi state. */ break; - /* If the above failed, then pi_state is NULL */ + case 1: + /* + * futex_proxy_trylock_atomic() acquired the user space + * futex. Adjust task_count. + */ + task_count++; + ret = 0; + break; + + /* + * If the above failed, then pi_state is NULL and + * waiter::requeue_state is correct. + */ case -EFAULT: double_unlock_hb(hb1, hb2); hb_waiters_dec(hb2); @@ -2112,18 +2352,17 @@ retry_private: break; } - /* - * Wake nr_wake waiters. For requeue_pi, if we acquired the - * lock, we already woke the top_waiter. If not, it will be - * woken by futex_unlock_pi(). - */ - if (++task_count <= nr_wake && !requeue_pi) { - mark_wake_futex(&wake_q, this); + /* Plain futexes just wake or requeue and are done */ + if (!requeue_pi) { + if (++task_count <= nr_wake) + mark_wake_futex(&wake_q, this); + else + requeue_futex(this, hb1, hb2, &key2); continue; } /* Ensure we requeue to the expected futex for requeue_pi. */ - if (requeue_pi && !match_futex(this->requeue_pi_key, &key2)) { + if (!match_futex(this->requeue_pi_key, &key2)) { ret = -EINVAL; break; } @@ -2131,54 +2370,66 @@ retry_private: /* * Requeue nr_requeue waiters and possibly one more in the case * of requeue_pi if we couldn't acquire the lock atomically. + * + * Prepare the waiter to take the rt_mutex. Take a refcount + * on the pi_state and store the pointer in the futex_q + * object of the waiter. */ - if (requeue_pi) { + get_pi_state(pi_state); + + /* Don't requeue when the waiter is already on the way out. */ + if (!futex_requeue_pi_prepare(this, pi_state)) { /* - * Prepare the waiter to take the rt_mutex. Take a - * refcount on the pi_state and store the pointer in - * the futex_q object of the waiter. + * Early woken waiter signaled that it is on the + * way out. Drop the pi_state reference and try the + * next waiter. @this->pi_state is still NULL. */ - get_pi_state(pi_state); - this->pi_state = pi_state; - ret = rt_mutex_start_proxy_lock(&pi_state->pi_mutex, - this->rt_waiter, - this->task); - if (ret == 1) { - /* - * We got the lock. We do neither drop the - * refcount on pi_state nor clear - * this->pi_state because the waiter needs the - * pi_state for cleaning up the user space - * value. It will drop the refcount after - * doing so. - */ - requeue_pi_wake_futex(this, &key2, hb2); - continue; - } else if (ret) { - /* - * rt_mutex_start_proxy_lock() detected a - * potential deadlock when we tried to queue - * that waiter. Drop the pi_state reference - * which we took above and remove the pointer - * to the state from the waiters futex_q - * object. - */ - this->pi_state = NULL; - put_pi_state(pi_state); - /* - * We stop queueing more waiters and let user - * space deal with the mess. - */ - break; - } + put_pi_state(pi_state); + continue; + } + + ret = rt_mutex_start_proxy_lock(&pi_state->pi_mutex, + this->rt_waiter, + this->task); + + if (ret == 1) { + /* + * We got the lock. We do neither drop the refcount + * on pi_state nor clear this->pi_state because the + * waiter needs the pi_state for cleaning up the + * user space value. It will drop the refcount + * after doing so. this::requeue_state is updated + * in the wakeup as well. + */ + requeue_pi_wake_futex(this, &key2, hb2); + task_count++; + } else if (!ret) { + /* Waiter is queued, move it to hb2 */ + requeue_futex(this, hb1, hb2, &key2); + futex_requeue_pi_complete(this, 0); + task_count++; + } else { + /* + * rt_mutex_start_proxy_lock() detected a potential + * deadlock when we tried to queue that waiter. + * Drop the pi_state reference which we took above + * and remove the pointer to the state from the + * waiters futex_q object. + */ + this->pi_state = NULL; + put_pi_state(pi_state); + futex_requeue_pi_complete(this, ret); + /* + * We stop queueing more waiters and let user space + * deal with the mess. + */ + break; } - requeue_futex(this, hb1, hb2, &key2); } /* - * We took an extra initial reference to the pi_state either - * in futex_proxy_trylock_atomic() or in lookup_pi_state(). We - * need to drop it here again. + * We took an extra initial reference to the pi_state in + * futex_proxy_trylock_atomic(). We need to drop it here again. */ put_pi_state(pi_state); @@ -2357,7 +2608,7 @@ static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, * Modifying pi_state _before_ the user space value would leave the * pi_state in an inconsistent state when we fault here, because we * need to drop the locks to handle the fault. This might be observed - * in the PID check in lookup_pi_state. + * in the PID checks when attaching to PI state . */ retry: if (!argowner) { @@ -2614,8 +2865,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, * * Setup the futex_q and locate the hash_bucket. Get the futex value and * compare it with the expected value. Handle atomic faults internally. - * Return with the hb lock held and a q.key reference on success, and unlocked - * with no q.key reference on failure. + * Return with the hb lock held on success, and unlocked on failure. * * Return: * - 0 - uaddr contains val and hb has been locked; @@ -2693,8 +2943,8 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, current->timer_slack_ns); retry: /* - * Prepare to wait on uaddr. On success, holds hb lock and increments - * q.key refs. + * Prepare to wait on uaddr. On success, it holds hb->lock and q + * is initialized. */ ret = futex_wait_setup(uaddr, val, flags, &q, &hb); if (ret) @@ -2705,7 +2955,6 @@ retry: /* If we were woken (and unqueued), we succeeded, whatever. */ ret = 0; - /* unqueue_me() drops q.key ref */ if (!unqueue_me(&q)) goto out; ret = -ETIMEDOUT; @@ -3072,27 +3321,22 @@ pi_faulted: } /** - * handle_early_requeue_pi_wakeup() - Detect early wakeup on the initial futex + * handle_early_requeue_pi_wakeup() - Handle early wakeup on the initial futex * @hb: the hash_bucket futex_q was original enqueued on * @q: the futex_q woken while waiting to be requeued - * @key2: the futex_key of the requeue target futex * @timeout: the timeout associated with the wait (NULL if none) * - * Detect if the task was woken on the initial futex as opposed to the requeue - * target futex. If so, determine if it was a timeout or a signal that caused - * the wakeup and return the appropriate error code to the caller. Must be - * called with the hb lock held. + * Determine the cause for the early wakeup. * * Return: - * - 0 = no early wakeup detected; - * - <0 = -ETIMEDOUT or -ERESTARTNOINTR + * -EWOULDBLOCK or -ETIMEDOUT or -ERESTARTNOINTR */ static inline int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, - struct futex_q *q, union futex_key *key2, + struct futex_q *q, struct hrtimer_sleeper *timeout) { - int ret = 0; + int ret; /* * With the hb lock held, we avoid races while we process the wakeup. @@ -3101,22 +3345,21 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * It can't be requeued from uaddr2 to something else since we don't * support a PI aware source futex for requeue. */ - if (!match_futex(&q->key, key2)) { - WARN_ON(q->lock_ptr && (&hb->lock != q->lock_ptr)); - /* - * We were woken prior to requeue by a timeout or a signal. - * Unqueue the futex_q and determine which it was. - */ - plist_del(&q->list, &hb->chain); - hb_waiters_dec(hb); + WARN_ON_ONCE(&hb->lock != q->lock_ptr); - /* Handle spurious wakeups gracefully */ - ret = -EWOULDBLOCK; - if (timeout && !timeout->task) - ret = -ETIMEDOUT; - else if (signal_pending(current)) - ret = -ERESTARTNOINTR; - } + /* + * We were woken prior to requeue by a timeout or a signal. + * Unqueue the futex_q and determine which it was. + */ + plist_del(&q->list, &hb->chain); + hb_waiters_dec(hb); + + /* Handle spurious wakeups gracefully */ + ret = -EWOULDBLOCK; + if (timeout && !timeout->task) + ret = -ETIMEDOUT; + else if (signal_pending(current)) + ret = -ERESTARTNOINTR; return ret; } @@ -3169,6 +3412,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, struct futex_hash_bucket *hb; union futex_key key2 = FUTEX_KEY_INIT; struct futex_q q = futex_q_init; + struct rt_mutex_base *pi_mutex; int res, ret; if (!IS_ENABLED(CONFIG_FUTEX_PI)) @@ -3198,8 +3442,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, q.requeue_pi_key = &key2; /* - * Prepare to wait on uaddr. On success, increments q.key (key1) ref - * count. + * Prepare to wait on uaddr. On success, it holds hb->lock and q + * is initialized. */ ret = futex_wait_setup(uaddr, val, flags, &q, &hb); if (ret) @@ -3218,32 +3462,22 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, /* Queue the futex_q, drop the hb lock, wait for wakeup. */ futex_wait_queue_me(hb, &q, to); - spin_lock(&hb->lock); - ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); - spin_unlock(&hb->lock); - if (ret) - goto out; - - /* - * In order for us to be here, we know our q.key == key2, and since - * we took the hb->lock above, we also know that futex_requeue() has - * completed and we no longer have to concern ourselves with a wakeup - * race with the atomic proxy lock acquisition by the requeue code. The - * futex_requeue dropped our key1 reference and incremented our key2 - * reference count. - */ + switch (futex_requeue_pi_wakeup_sync(&q)) { + case Q_REQUEUE_PI_IGNORE: + /* The waiter is still on uaddr1 */ + spin_lock(&hb->lock); + ret = handle_early_requeue_pi_wakeup(hb, &q, to); + spin_unlock(&hb->lock); + break; - /* - * Check if the requeue code acquired the second futex for us and do - * any pertinent fixup. - */ - if (!q.rt_waiter) { + case Q_REQUEUE_PI_LOCKED: + /* The requeue acquired the lock */ if (q.pi_state && (q.pi_state->owner != current)) { spin_lock(q.lock_ptr); ret = fixup_owner(uaddr2, &q, true); /* - * Drop the reference to the pi state which - * the requeue_pi() code acquired for us. + * Drop the reference to the pi state which the + * requeue_pi() code acquired for us. */ put_pi_state(q.pi_state); spin_unlock(q.lock_ptr); @@ -3253,18 +3487,14 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, */ ret = ret < 0 ? ret : 0; } - } else { - struct rt_mutex *pi_mutex; + break; - /* - * We have been woken up by futex_unlock_pi(), a timeout, or a - * signal. futex_unlock_pi() will not destroy the lock_ptr nor - * the pi_state. - */ - WARN_ON(!q.pi_state); + case Q_REQUEUE_PI_DONE: + /* Requeue completed. Current is 'pi_blocked_on' the rtmutex */ pi_mutex = &q.pi_state->pi_mutex; ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); + /* Current is not longer pi_blocked_on */ spin_lock(q.lock_ptr); if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) ret = 0; @@ -3284,17 +3514,21 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, unqueue_me_pi(&q); spin_unlock(q.lock_ptr); - } - if (ret == -EINTR) { - /* - * We've already been requeued, but cannot restart by calling - * futex_lock_pi() directly. We could restart this syscall, but - * it would detect that the user space "val" changed and return - * -EWOULDBLOCK. Save the overhead of the restart and return - * -EWOULDBLOCK directly. - */ - ret = -EWOULDBLOCK; + if (ret == -EINTR) { + /* + * We've already been requeued, but cannot restart + * by calling futex_lock_pi() directly. We could + * restart this syscall, but it would detect that + * the user space "val" changed and return + * -EWOULDBLOCK. Save the overhead of the restart + * and return -EWOULDBLOCK directly. + */ + ret = -EWOULDBLOCK; + } + break; + default: + BUG(); } out: diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index fbc54c2a7f23..10929eda9825 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -97,9 +97,6 @@ config GENERIC_MSI_IRQ_DOMAIN config IRQ_MSI_IOMMU bool -config HANDLE_DOMAIN_IRQ - bool - config IRQ_TIMINGS bool @@ -144,3 +141,10 @@ config GENERIC_IRQ_MULTI_HANDLER bool help Allow to specify the low level IRQ handler at run time. + +# Cavium Octeon is the last system to use this deprecated option +# Do not even think of enabling this on any new platform +config DEPRECATED_IRQ_CPU_ONOFFLINE + bool + depends on CAVIUM_OCTEON_SOC + default CAVIUM_OCTEON_SOC diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index 4d89ad4fae3b..f7ff8919dc9b 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -355,7 +355,7 @@ static int irq_build_affinity_masks(unsigned int startvec, unsigned int numvecs, goto fail_npresmsk; /* Stabilize the cpumasks */ - get_online_cpus(); + cpus_read_lock(); build_node_to_cpumask(node_to_cpumask); /* Spread on present CPUs starting from affd->pre_vectors */ @@ -384,7 +384,7 @@ static int irq_build_affinity_masks(unsigned int startvec, unsigned int numvecs, nr_others = ret; fail_build_affinity: - put_online_cpus(); + cpus_read_unlock(); if (ret >= 0) WARN_ON(nr_present + nr_others < numvecs); @@ -505,9 +505,9 @@ unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, if (affd->calc_sets) { set_vecs = maxvec - resv; } else { - get_online_cpus(); + cpus_read_lock(); set_vecs = cpumask_weight(cpu_possible_mask); - put_online_cpus(); + cpus_read_unlock(); } return resv + min(set_vecs, maxvec - resv); diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index a98bcfc4be7b..f895265d7548 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -1122,6 +1122,7 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set) } EXPORT_SYMBOL_GPL(irq_modify_status); +#ifdef CONFIG_DEPRECATED_IRQ_CPU_ONOFFLINE /** * irq_cpu_online - Invoke all irq_cpu_online functions. * @@ -1181,6 +1182,7 @@ void irq_cpu_offline(void) raw_spin_unlock_irqrestore(&desc->lock, flags); } } +#endif #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index 02236b13b359..39a41c56ad4f 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -166,7 +166,7 @@ void irq_migrate_all_off_this_cpu(void) raw_spin_unlock(&desc->lock); if (affinity_broken) { - pr_warn_ratelimited("IRQ %u: no longer affine to CPU%u\n", + pr_debug_ratelimited("IRQ %u: no longer affine to CPU%u\n", irq, smp_processor_id()); } } diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c index f8f23af6ab0d..6f29bf4c8515 100644 --- a/kernel/irq/generic-chip.c +++ b/kernel/irq/generic-chip.c @@ -25,6 +25,7 @@ static DEFINE_RAW_SPINLOCK(gc_lock); void irq_gc_noop(struct irq_data *d) { } +EXPORT_SYMBOL_GPL(irq_gc_noop); /** * irq_gc_mask_disable_reg - Mask chip via disable register @@ -44,6 +45,7 @@ void irq_gc_mask_disable_reg(struct irq_data *d) *ct->mask_cache &= ~mask; irq_gc_unlock(gc); } +EXPORT_SYMBOL_GPL(irq_gc_mask_disable_reg); /** * irq_gc_mask_set_bit - Mask chip via setting bit in mask register @@ -103,6 +105,7 @@ void irq_gc_unmask_enable_reg(struct irq_data *d) *ct->mask_cache |= mask; irq_gc_unlock(gc); } +EXPORT_SYMBOL_GPL(irq_gc_unmask_enable_reg); /** * irq_gc_ack_set_bit - Ack pending interrupt via setting bit @@ -240,9 +243,8 @@ irq_alloc_generic_chip(const char *name, int num_ct, unsigned int irq_base, void __iomem *reg_base, irq_flow_handler_t handler) { struct irq_chip_generic *gc; - unsigned long sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type); - gc = kzalloc(sz, GFP_KERNEL); + gc = kzalloc(struct_size(gc, chip_types, num_ct), GFP_KERNEL); if (gc) { irq_init_generic_chip(gc, name, num_ct, irq_base, reg_base, handler); @@ -288,8 +290,11 @@ int __irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip, { struct irq_domain_chip_generic *dgc; struct irq_chip_generic *gc; - int numchips, sz, i; unsigned long flags; + int numchips, i; + size_t dgc_sz; + size_t gc_sz; + size_t sz; void *tmp; if (d->gc) @@ -300,8 +305,9 @@ int __irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip, return -EINVAL; /* Allocate a pointer, generic chip and chiptypes for each chip */ - sz = sizeof(*dgc) + numchips * sizeof(gc); - sz += numchips * (sizeof(*gc) + num_ct * sizeof(struct irq_chip_type)); + gc_sz = struct_size(gc, chip_types, num_ct); + dgc_sz = struct_size(dgc, gc, numchips); + sz = dgc_sz + numchips * gc_sz; tmp = dgc = kzalloc(sz, GFP_KERNEL); if (!dgc) @@ -314,7 +320,7 @@ int __irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip, d->gc = dgc; /* Calc pointer to the first generic chip */ - tmp += sizeof(*dgc) + numchips * sizeof(gc); + tmp += dgc_sz; for (i = 0; i < numchips; i++) { /* Store the pointer to the generic chip */ dgc->gc[i] = gc = tmp; @@ -331,7 +337,7 @@ int __irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip, list_add_tail(&gc->list, &gc_list); raw_spin_unlock_irqrestore(&gc_lock, flags); /* Calc pointer to the next generic chip */ - tmp += sizeof(*gc) + num_ct * sizeof(struct irq_chip_type); + tmp += gc_sz; } return 0; } diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 221d80c31e94..27182003b879 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -14,6 +14,8 @@ #include <linux/interrupt.h> #include <linux/kernel_stat.h> +#include <asm/irq_regs.h> + #include <trace/events/irq.h> #include "internals.h" @@ -226,4 +228,20 @@ int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) handle_arch_irq = handle_irq; return 0; } + +/** + * generic_handle_arch_irq - root irq handler for architectures which do no + * entry accounting themselves + * @regs: Register file coming from the low-level handling code + */ +asmlinkage void noinstr generic_handle_arch_irq(struct pt_regs *regs) +{ + struct pt_regs *old_regs; + + irq_enter(); + old_regs = set_irq_regs(regs); + handle_arch_irq(regs); + set_irq_regs(old_regs); + irq_exit(); +} #endif diff --git a/kernel/irq/ipi.c b/kernel/irq/ipi.c index 52f11c791bf8..08ce7da3b57c 100644 --- a/kernel/irq/ipi.c +++ b/kernel/irq/ipi.c @@ -14,11 +14,11 @@ /** * irq_reserve_ipi() - Setup an IPI to destination cpumask * @domain: IPI domain - * @dest: cpumask of cpus which can receive the IPI + * @dest: cpumask of CPUs which can receive the IPI * * Allocate a virq that can be used to send IPI to any CPU in dest mask. * - * On success it'll return linux irq number and error code on failure + * Return: Linux IRQ number on success or error code on failure */ int irq_reserve_ipi(struct irq_domain *domain, const struct cpumask *dest) @@ -104,13 +104,13 @@ free_descs: /** * irq_destroy_ipi() - unreserve an IPI that was previously allocated - * @irq: linux irq number to be destroyed - * @dest: cpumask of cpus which should have the IPI removed + * @irq: Linux IRQ number to be destroyed + * @dest: cpumask of CPUs which should have the IPI removed * * The IPIs allocated with irq_reserve_ipi() are returned to the system * destroying all virqs associated with them. * - * Return 0 on success or error code on failure. + * Return: %0 on success or error code on failure. */ int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) { @@ -150,14 +150,14 @@ int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest) } /** - * ipi_get_hwirq - Get the hwirq associated with an IPI to a cpu - * @irq: linux irq number - * @cpu: the target cpu + * ipi_get_hwirq - Get the hwirq associated with an IPI to a CPU + * @irq: Linux IRQ number + * @cpu: the target CPU * * When dealing with coprocessors IPI, we need to inform the coprocessor of * the hwirq it needs to use to receive and send IPIs. * - * Returns hwirq value on success and INVALID_HWIRQ on failure. + * Return: hwirq value on success or INVALID_HWIRQ on failure. */ irq_hw_number_t ipi_get_hwirq(unsigned int irq, unsigned int cpu) { @@ -216,7 +216,7 @@ static int ipi_send_verify(struct irq_chip *chip, struct irq_data *data, * This function is for architecture or core code to speed up IPI sending. Not * usable from driver code. * - * Returns zero on success and negative error number on failure. + * Return: %0 on success or negative error number on failure. */ int __ipi_send_single(struct irq_desc *desc, unsigned int cpu) { @@ -250,7 +250,7 @@ int __ipi_send_single(struct irq_desc *desc, unsigned int cpu) } /** - * ipi_send_mask - send an IPI to target Linux SMP CPU(s) + * __ipi_send_mask - send an IPI to target Linux SMP CPU(s) * @desc: pointer to irq_desc of the IRQ * @dest: dest CPU(s), must be a subset of the mask passed to * irq_reserve_ipi() @@ -258,7 +258,7 @@ int __ipi_send_single(struct irq_desc *desc, unsigned int cpu) * This function is for architecture or core code to speed up IPI sending. Not * usable from driver code. * - * Returns zero on success and negative error number on failure. + * Return: %0 on success or negative error number on failure. */ int __ipi_send_mask(struct irq_desc *desc, const struct cpumask *dest) { @@ -298,11 +298,11 @@ int __ipi_send_mask(struct irq_desc *desc, const struct cpumask *dest) /** * ipi_send_single - Send an IPI to a single CPU - * @virq: linux irq number from irq_reserve_ipi() + * @virq: Linux IRQ number from irq_reserve_ipi() * @cpu: destination CPU, must in the destination mask passed to * irq_reserve_ipi() * - * Returns zero on success and negative error number on failure. + * Return: %0 on success or negative error number on failure. */ int ipi_send_single(unsigned int virq, unsigned int cpu) { @@ -319,11 +319,11 @@ EXPORT_SYMBOL_GPL(ipi_send_single); /** * ipi_send_mask - Send an IPI to target CPU(s) - * @virq: linux irq number from irq_reserve_ipi() + * @virq: Linux IRQ number from irq_reserve_ipi() * @dest: dest CPU(s), must be a subset of the mask passed to * irq_reserve_ipi() * - * Returns zero on success and negative error number on failure. + * Return: %0 on success or negative error number on failure. */ int ipi_send_mask(unsigned int virq, const struct cpumask *dest) { diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index fadb93766020..2267e6527db3 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -188,7 +188,7 @@ static ssize_t hwirq_show(struct kobject *kobj, raw_spin_lock_irq(&desc->lock); if (desc->irq_data.domain) - ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq); + ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq); raw_spin_unlock_irq(&desc->lock); return ret; @@ -646,13 +646,16 @@ int handle_irq_desc(struct irq_desc *desc) generic_handle_irq_desc(desc); return 0; } -EXPORT_SYMBOL_GPL(handle_irq_desc); /** * generic_handle_irq - Invoke the handler for a particular irq * @irq: The irq number to handle * - */ + * Returns: 0 on success, or -EINVAL if conversion has failed + * + * This function must be called from an IRQ context with irq regs + * initialized. + */ int generic_handle_irq(unsigned int irq) { return handle_irq_desc(irq_to_desc(irq)); @@ -662,89 +665,39 @@ EXPORT_SYMBOL_GPL(generic_handle_irq); #ifdef CONFIG_IRQ_DOMAIN /** * generic_handle_domain_irq - Invoke the handler for a HW irq belonging - * to a domain, usually for a non-root interrupt - * controller + * to a domain. * @domain: The domain where to perform the lookup * @hwirq: The HW irq number to convert to a logical one * * Returns: 0 on success, or -EINVAL if conversion has failed * + * This function must be called from an IRQ context with irq regs + * initialized. */ int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq) { + WARN_ON_ONCE(!in_irq()); return handle_irq_desc(irq_resolve_mapping(domain, hwirq)); } EXPORT_SYMBOL_GPL(generic_handle_domain_irq); -#ifdef CONFIG_HANDLE_DOMAIN_IRQ /** - * handle_domain_irq - Invoke the handler for a HW irq belonging to a domain, - * usually for a root interrupt controller + * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging + * to a domain. * @domain: The domain where to perform the lookup * @hwirq: The HW irq number to convert to a logical one - * @regs: Register file coming from the low-level handling code * * Returns: 0 on success, or -EINVAL if conversion has failed - */ -int handle_domain_irq(struct irq_domain *domain, - unsigned int hwirq, struct pt_regs *regs) -{ - struct pt_regs *old_regs = set_irq_regs(regs); - struct irq_desc *desc; - int ret = 0; - - irq_enter(); - - /* The irqdomain code provides boundary checks */ - desc = irq_resolve_mapping(domain, hwirq); - if (likely(desc)) - handle_irq_desc(desc); - else - ret = -EINVAL; - - irq_exit(); - set_irq_regs(old_regs); - return ret; -} - -/** - * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain - * @domain: The domain where to perform the lookup - * @hwirq: The HW irq number to convert to a logical one - * @regs: Register file coming from the low-level handling code * - * This function must be called from an NMI context. - * - * Returns: 0 on success, or -EINVAL if conversion has failed - */ -int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq, - struct pt_regs *regs) + * This function must be called from an NMI context with irq regs + * initialized. + **/ +int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq) { - struct pt_regs *old_regs = set_irq_regs(regs); - struct irq_desc *desc; - int ret = 0; - - /* - * NMI context needs to be setup earlier in order to deal with tracing. - */ - WARN_ON(!in_nmi()); - - desc = irq_resolve_mapping(domain, hwirq); - - /* - * ack_bad_irq is not NMI-safe, just report - * an invalid interrupt. - */ - if (likely(desc)) - handle_irq_desc(desc); - else - ret = -EINVAL; - - set_irq_regs(old_regs); - return ret; + WARN_ON_ONCE(!in_nmi()); + return handle_irq_desc(irq_resolve_mapping(domain, hwirq)); } #endif -#endif /* Dynamic interrupt handling */ diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 51c483ce2447..4d8fc65cf38f 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -136,7 +136,7 @@ EXPORT_SYMBOL_GPL(irq_domain_free_fwnode); * Allocates and initializes an irq_domain structure. * Returns pointer to IRQ domain, or NULL on failure. */ -struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size, +struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, unsigned int size, irq_hw_number_t hwirq_max, int direct_max, const struct irq_domain_ops *ops, void *host_data) @@ -491,6 +491,7 @@ struct irq_domain *irq_get_default_host(void) { return irq_default_domain; } +EXPORT_SYMBOL_GPL(irq_get_default_host); static bool irq_domain_is_nomap(struct irq_domain *domain) { @@ -1215,6 +1216,7 @@ int irq_domain_disconnect_hierarchy(struct irq_domain *domain, irqd->chip = ERR_PTR(-ENOTCONN); return 0; } +EXPORT_SYMBOL_GPL(irq_domain_disconnect_hierarchy); static int irq_domain_trim_hierarchy(unsigned int virq) { diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ef30b4762947..7405e384e5ed 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -25,12 +25,11 @@ #include "internals.h" #if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT) -__read_mostly bool force_irqthreads; -EXPORT_SYMBOL_GPL(force_irqthreads); +DEFINE_STATIC_KEY_FALSE(force_irqthreads_key); static int __init setup_forced_irqthreads(char *arg) { - force_irqthreads = true; + static_branch_enable(&force_irqthreads_key); return 0; } early_param("threadirqs", setup_forced_irqthreads); @@ -1260,8 +1259,10 @@ static int irq_thread(void *data) irqreturn_t (*handler_fn)(struct irq_desc *desc, struct irqaction *action); - if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD, - &action->thread_flags)) + sched_set_fifo(current); + + if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD, + &action->thread_flags)) handler_fn = irq_forced_thread_fn; else handler_fn = irq_thread_fn; @@ -1322,7 +1323,7 @@ EXPORT_SYMBOL_GPL(irq_wake_thread); static int irq_setup_forced_threading(struct irqaction *new) { - if (!force_irqthreads) + if (!force_irqthreads()) return 0; if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) return 0; @@ -1425,8 +1426,6 @@ setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) if (IS_ERR(t)) return PTR_ERR(t); - sched_set_fifo(t); - /* * We keep the reference to the task struct even if * the thread dies to avoid that the interrupt code @@ -2072,9 +2071,9 @@ const void *free_nmi(unsigned int irq, void *dev_id) * request_threaded_irq - allocate an interrupt line * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs. - * Primary handler for threaded interrupts - * If NULL and thread_fn != NULL the default - * primary handler is installed + * Primary handler for threaded interrupts. + * If handler is NULL and thread_fn != NULL + * the default primary handler is installed. * @thread_fn: Function called from the irq handler thread * If NULL, no irq thread is created * @irqflags: Interrupt type flags @@ -2108,7 +2107,7 @@ const void *free_nmi(unsigned int irq, void *dev_id) * * IRQF_SHARED Interrupt is shared * IRQF_TRIGGER_* Specify active edge(s) or level - * + * IRQF_ONESHOT Run thread_fn with interrupt line masked */ int request_threaded_irq(unsigned int irq, irq_handler_t handler, irq_handler_t thread_fn, unsigned long irqflags, @@ -2828,7 +2827,7 @@ EXPORT_SYMBOL_GPL(irq_get_irqchip_state); * This call sets the internal irqchip state of an interrupt, * depending on the value of @which. * - * This function should be called with preemption disabled if the + * This function should be called with migration disabled if the * interrupt controller has per-cpu registers. */ int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c index 578596e41cb6..bbfb26489aa1 100644 --- a/kernel/irq/matrix.c +++ b/kernel/irq/matrix.c @@ -280,7 +280,8 @@ void irq_matrix_remove_managed(struct irq_matrix *m, const struct cpumask *msk) /** * irq_matrix_alloc_managed - Allocate a managed interrupt in a CPU map * @m: Matrix pointer - * @cpu: On which CPU the interrupt should be allocated + * @msk: Which CPUs to search in + * @mapped_cpu: Pointer to store the CPU for which the irq was allocated */ int irq_matrix_alloc_managed(struct irq_matrix *m, const struct cpumask *msk, unsigned int *mapped_cpu) diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 85df3ca03efe..6a5ecee6e567 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -14,17 +14,20 @@ #include <linux/irqdomain.h> #include <linux/msi.h> #include <linux/slab.h> +#include <linux/pci.h> #include "internals.h" /** - * alloc_msi_entry - Allocate an initialize msi_entry + * alloc_msi_entry - Allocate an initialized msi_desc * @dev: Pointer to the device for which this is allocated * @nvec: The number of vectors used in this entry * @affinity: Optional pointer to an affinity mask array size of @nvec * - * If @affinity is not NULL then an affinity array[@nvec] is allocated + * If @affinity is not %NULL then an affinity array[@nvec] is allocated * and the affinity masks and flags from @affinity are copied. + * + * Return: pointer to allocated &msi_desc on success or %NULL on failure */ struct msi_desc *alloc_msi_entry(struct device *dev, int nvec, const struct irq_affinity_desc *affinity) @@ -69,6 +72,139 @@ void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) } EXPORT_SYMBOL_GPL(get_cached_msi_msg); +static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct msi_desc *entry; + bool is_msix = false; + unsigned long irq; + int retval; + + retval = kstrtoul(attr->attr.name, 10, &irq); + if (retval) + return retval; + + entry = irq_get_msi_desc(irq); + if (!entry) + return -ENODEV; + + if (dev_is_pci(dev)) + is_msix = entry->msi_attrib.is_msix; + + return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi"); +} + +/** + * msi_populate_sysfs - Populate msi_irqs sysfs entries for devices + * @dev: The device(PCI, platform etc) who will get sysfs entries + * + * Return attribute_group ** so that specific bus MSI can save it to + * somewhere during initilizing msi irqs. If devices has no MSI irq, + * return NULL; if it fails to populate sysfs, return ERR_PTR + */ +const struct attribute_group **msi_populate_sysfs(struct device *dev) +{ + const struct attribute_group **msi_irq_groups; + struct attribute **msi_attrs, *msi_attr; + struct device_attribute *msi_dev_attr; + struct attribute_group *msi_irq_group; + struct msi_desc *entry; + int ret = -ENOMEM; + int num_msi = 0; + int count = 0; + int i; + + /* Determine how many msi entries we have */ + for_each_msi_entry(entry, dev) + num_msi += entry->nvec_used; + if (!num_msi) + return NULL; + + /* Dynamically create the MSI attributes for the device */ + msi_attrs = kcalloc(num_msi + 1, sizeof(void *), GFP_KERNEL); + if (!msi_attrs) + return ERR_PTR(-ENOMEM); + + for_each_msi_entry(entry, dev) { + for (i = 0; i < entry->nvec_used; i++) { + msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL); + if (!msi_dev_attr) + goto error_attrs; + msi_attrs[count] = &msi_dev_attr->attr; + + sysfs_attr_init(&msi_dev_attr->attr); + msi_dev_attr->attr.name = kasprintf(GFP_KERNEL, "%d", + entry->irq + i); + if (!msi_dev_attr->attr.name) + goto error_attrs; + msi_dev_attr->attr.mode = 0444; + msi_dev_attr->show = msi_mode_show; + ++count; + } + } + + msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL); + if (!msi_irq_group) + goto error_attrs; + msi_irq_group->name = "msi_irqs"; + msi_irq_group->attrs = msi_attrs; + + msi_irq_groups = kcalloc(2, sizeof(void *), GFP_KERNEL); + if (!msi_irq_groups) + goto error_irq_group; + msi_irq_groups[0] = msi_irq_group; + + ret = sysfs_create_groups(&dev->kobj, msi_irq_groups); + if (ret) + goto error_irq_groups; + + return msi_irq_groups; + +error_irq_groups: + kfree(msi_irq_groups); +error_irq_group: + kfree(msi_irq_group); +error_attrs: + count = 0; + msi_attr = msi_attrs[count]; + while (msi_attr) { + msi_dev_attr = container_of(msi_attr, struct device_attribute, attr); + kfree(msi_attr->name); + kfree(msi_dev_attr); + ++count; + msi_attr = msi_attrs[count]; + } + kfree(msi_attrs); + return ERR_PTR(ret); +} + +/** + * msi_destroy_sysfs - Destroy msi_irqs sysfs entries for devices + * @dev: The device(PCI, platform etc) who will remove sysfs entries + * @msi_irq_groups: attribute_group for device msi_irqs entries + */ +void msi_destroy_sysfs(struct device *dev, const struct attribute_group **msi_irq_groups) +{ + struct device_attribute *dev_attr; + struct attribute **msi_attrs; + int count = 0; + + if (msi_irq_groups) { + sysfs_remove_groups(&dev->kobj, msi_irq_groups); + msi_attrs = msi_irq_groups[0]->attrs; + while (msi_attrs[count]) { + dev_attr = container_of(msi_attrs[count], + struct device_attribute, attr); + kfree(dev_attr->attr.name); + kfree(dev_attr); + ++count; + } + kfree(msi_attrs); + kfree(msi_irq_groups[0]); + kfree(msi_irq_groups); + } +} + #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN static inline void irq_chip_write_msi_msg(struct irq_data *data, struct msi_msg *msg) @@ -97,6 +233,8 @@ static void msi_check_level(struct irq_domain *domain, struct msi_msg *msg) * * Intended to be used by MSI interrupt controllers which are * implemented with hierarchical domains. + * + * Return: IRQ_SET_MASK_* result code */ int msi_domain_set_affinity(struct irq_data *irq_data, const struct cpumask *mask, bool force) @@ -277,10 +415,12 @@ static void msi_domain_update_chip_ops(struct msi_domain_info *info) } /** - * msi_create_irq_domain - Create a MSI interrupt domain + * msi_create_irq_domain - Create an MSI interrupt domain * @fwnode: Optional fwnode of the interrupt controller * @info: MSI domain info * @parent: Parent irq domain + * + * Return: pointer to the created &struct irq_domain or %NULL on failure */ struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode, struct msi_domain_info *info, @@ -487,7 +627,7 @@ cleanup: * are allocated * @nvec: The number of interrupts to allocate * - * Returns 0 on success or an error code. + * Return: %0 on success or an error code. */ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, int nvec) @@ -524,7 +664,7 @@ void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev) } /** - * __msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev + * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated to @dev * @domain: The domain to managing the interrupts * @dev: Pointer to device struct of the device for which the interrupts * are free @@ -541,8 +681,7 @@ void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev) * msi_get_domain_info - Get the MSI interrupt domain info for @domain * @domain: The interrupt domain to retrieve data from * - * Returns the pointer to the msi_domain_info stored in - * @domain->host_data. + * Return: the pointer to the msi_domain_info stored in @domain->host_data. */ struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain) { diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c index ce0adb22ee96..ca71123a6130 100644 --- a/kernel/irq/pm.c +++ b/kernel/irq/pm.c @@ -227,7 +227,7 @@ unlock: } /** - * irq_pm_syscore_ops - enable interrupt lines early + * irq_pm_syscore_resume - enable interrupt lines early * * Enable all interrupt lines with %IRQF_EARLY_RESUME set. */ diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 7c5cd42df3b9..ee595ec09778 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -513,7 +513,7 @@ int show_interrupts(struct seq_file *p, void *v) seq_printf(p, " %8s", "None"); } if (desc->irq_data.domain) - seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq); + seq_printf(p, " %*lu", prec, desc->irq_data.hwirq); else seq_printf(p, " %*s", prec, ""); #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index c481d8458325..02b2daf07441 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -447,6 +447,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); static int __init irqfixup_setup(char *str) { + if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + pr_warn("irqfixup boot option not supported with PREEMPT_RT\n"); + return 1; + } irqfixup = 1; printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); printk(KERN_WARNING "This may impact system performance.\n"); @@ -459,6 +463,10 @@ module_param(irqfixup, int, 0644); static int __init irqpoll_setup(char *str) { + if (IS_ENABLED(CONFIG_PREEMPT_RT)) { + pr_warn("irqpoll boot option not supported with PREEMPT_RT\n"); + return 1; + } irqfixup = 2; printk(KERN_WARNING "Misrouted IRQ fixup and polling support " "enabled\n"); diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c index 4d2a702d7aa9..c43e2ac2f8de 100644 --- a/kernel/irq/timings.c +++ b/kernel/irq/timings.c @@ -799,12 +799,14 @@ static int __init irq_timings_test_irqs(struct timings_intervals *ti) __irq_timings_store(irq, irqs, ti->intervals[i]); if (irqs->circ_timings[i & IRQ_TIMINGS_MASK] != index) { + ret = -EBADSLT; pr_err("Failed to store in the circular buffer\n"); goto out; } } if (irqs->count != ti->count) { + ret = -ERANGE; pr_err("Count differs\n"); goto out; } diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h deleted file mode 100644 index 530ae1bda8e7..000000000000 --- a/kernel/kcsan/atomic.h +++ /dev/null @@ -1,23 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Rules for implicitly atomic memory accesses. - * - * Copyright (C) 2019, Google LLC. - */ - -#ifndef _KERNEL_KCSAN_ATOMIC_H -#define _KERNEL_KCSAN_ATOMIC_H - -#include <linux/types.h> - -/* - * Special rules for certain memory where concurrent conflicting accesses are - * common, however, the current convention is to not mark them; returns true if - * access to @ptr should be considered atomic. Called from slow-path. - */ -static bool kcsan_is_atomic_special(const volatile void *ptr) -{ - return false; -} - -#endif /* _KERNEL_KCSAN_ATOMIC_H */ diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index 26709ea65c71..76e67d1e02d4 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -20,9 +20,9 @@ #include <linux/sched.h> #include <linux/uaccess.h> -#include "atomic.h" #include "encoding.h" #include "kcsan.h" +#include "permissive.h" static bool kcsan_early_enable = IS_ENABLED(CONFIG_KCSAN_EARLY_ENABLE); unsigned int kcsan_udelay_task = CONFIG_KCSAN_UDELAY_TASK; @@ -301,9 +301,9 @@ static inline void reset_kcsan_skip(void) this_cpu_write(kcsan_skip, skip_count); } -static __always_inline bool kcsan_is_enabled(void) +static __always_inline bool kcsan_is_enabled(struct kcsan_ctx *ctx) { - return READ_ONCE(kcsan_enabled) && get_ctx()->disable_count == 0; + return READ_ONCE(kcsan_enabled) && !ctx->disable_count; } /* Introduce delay depending on context and configuration. */ @@ -353,10 +353,18 @@ static noinline void kcsan_found_watchpoint(const volatile void *ptr, atomic_long_t *watchpoint, long encoded_watchpoint) { + const bool is_assert = (type & KCSAN_ACCESS_ASSERT) != 0; + struct kcsan_ctx *ctx = get_ctx(); unsigned long flags; bool consumed; - if (!kcsan_is_enabled()) + /* + * We know a watchpoint exists. Let's try to keep the race-window + * between here and finally consuming the watchpoint below as small as + * possible -- avoid unneccessarily complex code until consumed. + */ + + if (!kcsan_is_enabled(ctx)) return; /* @@ -364,14 +372,22 @@ static noinline void kcsan_found_watchpoint(const volatile void *ptr, * reporting a race where e.g. the writer set up the watchpoint, but the * reader has access_mask!=0, we have to ignore the found watchpoint. */ - if (get_ctx()->access_mask != 0) + if (ctx->access_mask) return; /* - * Consume the watchpoint as soon as possible, to minimize the chances - * of !consumed. Consuming the watchpoint must always be guarded by - * kcsan_is_enabled() check, as otherwise we might erroneously - * triggering reports when disabled. + * If the other thread does not want to ignore the access, and there was + * a value change as a result of this thread's operation, we will still + * generate a report of unknown origin. + * + * Use CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN=n to filter. + */ + if (!is_assert && kcsan_ignore_address(ptr)) + return; + + /* + * Consuming the watchpoint must be guarded by kcsan_is_enabled() to + * avoid erroneously triggering reports if the context is disabled. */ consumed = try_consume_watchpoint(watchpoint, encoded_watchpoint); @@ -391,7 +407,7 @@ static noinline void kcsan_found_watchpoint(const volatile void *ptr, atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_REPORT_RACES]); } - if ((type & KCSAN_ACCESS_ASSERT) != 0) + if (is_assert) atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_ASSERT_FAILURES]); else atomic_long_inc(&kcsan_counters[KCSAN_COUNTER_DATA_RACES]); @@ -409,6 +425,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) unsigned long access_mask; enum kcsan_value_change value_change = KCSAN_VALUE_CHANGE_MAYBE; unsigned long ua_flags = user_access_save(); + struct kcsan_ctx *ctx = get_ctx(); unsigned long irq_flags = 0; /* @@ -417,16 +434,14 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) */ reset_kcsan_skip(); - if (!kcsan_is_enabled()) + if (!kcsan_is_enabled(ctx)) goto out; /* - * Special atomic rules: unlikely to be true, so we check them here in - * the slow-path, and not in the fast-path in is_atomic(). Call after - * kcsan_is_enabled(), as we may access memory that is not yet - * initialized during early boot. + * Check to-ignore addresses after kcsan_is_enabled(), as we may access + * memory that is not yet initialized during early boot. */ - if (!is_assert && kcsan_is_atomic_special(ptr)) + if (!is_assert && kcsan_ignore_address(ptr)) goto out; if (!check_encodable((unsigned long)ptr, size)) { @@ -479,15 +494,6 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) break; /* ignore; we do not diff the values */ } - if (IS_ENABLED(CONFIG_KCSAN_DEBUG)) { - kcsan_disable_current(); - pr_err("watching %s, size: %zu, addr: %px [slot: %d, encoded: %lx]\n", - is_write ? "write" : "read", size, ptr, - watchpoint_slot((unsigned long)ptr), - encode_watchpoint((unsigned long)ptr, size, is_write)); - kcsan_enable_current(); - } - /* * Delay this thread, to increase probability of observing a racy * conflicting access. @@ -498,7 +504,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) * Re-read value, and check if it is as expected; if not, we infer a * racy access. */ - access_mask = get_ctx()->access_mask; + access_mask = ctx->access_mask; new = 0; switch (size) { case 1: @@ -521,8 +527,14 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type) if (access_mask) diff &= access_mask; - /* Were we able to observe a value-change? */ - if (diff != 0) + /* + * Check if we observed a value change. + * + * Also check if the data race should be ignored (the rules depend on + * non-zero diff); if it is to be ignored, the below rules for + * KCSAN_VALUE_CHANGE_MAYBE apply. + */ + if (diff && !kcsan_ignore_data_race(size, type, old, new, diff)) value_change = KCSAN_VALUE_CHANGE_TRUE; /* Check if this access raced with another. */ @@ -644,6 +656,15 @@ void __init kcsan_init(void) pr_info("enabled early\n"); WRITE_ONCE(kcsan_enabled, true); } + + if (IS_ENABLED(CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY) || + IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC) || + IS_ENABLED(CONFIG_KCSAN_PERMISSIVE) || + IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) { + pr_warn("non-strict mode configured - use CONFIG_KCSAN_STRICT=y to see all data races\n"); + } else { + pr_info("strict mode configured\n"); + } } /* === Exported interface =================================================== */ diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c index e65de172ccf7..1d1d1b0e4248 100644 --- a/kernel/kcsan/debugfs.c +++ b/kernel/kcsan/debugfs.c @@ -64,7 +64,7 @@ static noinline void microbenchmark(unsigned long iters) { const struct kcsan_ctx ctx_save = current->kcsan_ctx; const bool was_enabled = READ_ONCE(kcsan_enabled); - cycles_t cycles; + u64 cycles; /* We may have been called from an atomic region; reset context. */ memset(¤t->kcsan_ctx, 0, sizeof(current->kcsan_ctx)); diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c index 8bcffbdef3d3..dc55fd5a36fc 100644 --- a/kernel/kcsan/kcsan_test.c +++ b/kernel/kcsan/kcsan_test.c @@ -414,6 +414,14 @@ static noinline void test_kernel_atomic_builtins(void) __atomic_load_n(&test_var, __ATOMIC_RELAXED); } +static noinline void test_kernel_xor_1bit(void) +{ + /* Do not report data races between the read-writes. */ + kcsan_nestable_atomic_begin(); + test_var ^= 0x10000; + kcsan_nestable_atomic_end(); +} + /* ===== Test cases ===== */ /* Simple test with normal data race. */ @@ -952,6 +960,29 @@ static void test_atomic_builtins(struct kunit *test) KUNIT_EXPECT_FALSE(test, match_never); } +__no_kcsan +static void test_1bit_value_change(struct kunit *test) +{ + const struct expect_report expect = { + .access = { + { test_kernel_read, &test_var, sizeof(test_var), 0 }, + { test_kernel_xor_1bit, &test_var, sizeof(test_var), __KCSAN_ACCESS_RW(KCSAN_ACCESS_WRITE) }, + }, + }; + bool match = false; + + begin_test_checks(test_kernel_read, test_kernel_xor_1bit); + do { + match = IS_ENABLED(CONFIG_KCSAN_PERMISSIVE) + ? report_available() + : report_matches(&expect); + } while (!end_test_checks(match)); + if (IS_ENABLED(CONFIG_KCSAN_PERMISSIVE)) + KUNIT_EXPECT_FALSE(test, match); + else + KUNIT_EXPECT_TRUE(test, match); +} + /* * Generate thread counts for all test cases. Values generated are in interval * [2, 5] followed by exponentially increasing thread counts from 8 to 32. @@ -1024,6 +1055,7 @@ static struct kunit_case kcsan_test_cases[] = { KCSAN_KUNIT_CASE(test_jiffies_noreport), KCSAN_KUNIT_CASE(test_seqlock_noreport), KCSAN_KUNIT_CASE(test_atomic_builtins), + KCSAN_KUNIT_CASE(test_1bit_value_change), {}, }; diff --git a/kernel/kcsan/permissive.h b/kernel/kcsan/permissive.h new file mode 100644 index 000000000000..2c01fe4a59ee --- /dev/null +++ b/kernel/kcsan/permissive.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Special rules for ignoring entire classes of data-racy memory accesses. None + * of the rules here imply that such data races are generally safe! + * + * All rules in this file can be configured via CONFIG_KCSAN_PERMISSIVE. Keep + * them separate from core code to make it easier to audit. + * + * Copyright (C) 2019, Google LLC. + */ + +#ifndef _KERNEL_KCSAN_PERMISSIVE_H +#define _KERNEL_KCSAN_PERMISSIVE_H + +#include <linux/bitops.h> +#include <linux/sched.h> +#include <linux/types.h> + +/* + * Access ignore rules based on address. + */ +static __always_inline bool kcsan_ignore_address(const volatile void *ptr) +{ + if (!IS_ENABLED(CONFIG_KCSAN_PERMISSIVE)) + return false; + + /* + * Data-racy bitops on current->flags are too common, ignore completely + * for now. + */ + return ptr == ¤t->flags; +} + +/* + * Data race ignore rules based on access type and value change patterns. + */ +static bool +kcsan_ignore_data_race(size_t size, int type, u64 old, u64 new, u64 diff) +{ + if (!IS_ENABLED(CONFIG_KCSAN_PERMISSIVE)) + return false; + + /* + * Rules here are only for plain read accesses, so that we still report + * data races between plain read-write accesses. + */ + if (type || size > sizeof(long)) + return false; + + /* + * A common pattern is checking/setting just 1 bit in a variable; for + * example: + * + * if (flags & SOME_FLAG) { ... } + * + * and elsewhere flags is updated concurrently: + * + * flags |= SOME_OTHER_FLAG; // just 1 bit + * + * While it is still recommended that such accesses be marked + * appropriately, in many cases these types of data races are so common + * that marking them all is often unrealistic and left to maintainer + * preference. + * + * The assumption in all cases is that with all known compiler + * optimizations (including those that tear accesses), because no more + * than 1 bit changed, the plain accesses are safe despite the presence + * of data races. + * + * The rules here will ignore the data races if we observe no more than + * 1 bit changed. + * + * Of course many operations can effecively change just 1 bit, but the + * general assuption that data races involving 1-bit changes can be + * tolerated still applies. + * + * And in case a true bug is missed, the bug likely manifests as a + * reportable data race elsewhere. + */ + if (hweight64(diff) == 1) { + /* + * Exception: Report data races where the values look like + * ordinary booleans (one of them was 0 and the 0th bit was + * changed) More often than not, they come with interesting + * memory ordering requirements, so let's report them. + */ + if (!((!old || !new) && diff == 1)) + return true; + } + + return false; +} + +#endif /* _KERNEL_KCSAN_PERMISSIVE_H */ diff --git a/kernel/kexec.c b/kernel/kexec.c index c82c6c06f051..b5e40f069768 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -19,26 +19,9 @@ #include "kexec_internal.h" -static int copy_user_segment_list(struct kimage *image, - unsigned long nr_segments, - struct kexec_segment __user *segments) -{ - int ret; - size_t segment_bytes; - - /* Read in the segments */ - image->nr_segments = nr_segments; - segment_bytes = nr_segments * sizeof(*segments); - ret = copy_from_user(image->segment, segments, segment_bytes); - if (ret) - ret = -EFAULT; - - return ret; -} - static int kimage_alloc_init(struct kimage **rimage, unsigned long entry, unsigned long nr_segments, - struct kexec_segment __user *segments, + struct kexec_segment *segments, unsigned long flags) { int ret; @@ -58,10 +41,8 @@ static int kimage_alloc_init(struct kimage **rimage, unsigned long entry, return -ENOMEM; image->start = entry; - - ret = copy_user_segment_list(image, nr_segments, segments); - if (ret) - goto out_free_image; + image->nr_segments = nr_segments; + memcpy(image->segment, segments, nr_segments * sizeof(*segments)); if (kexec_on_panic) { /* Enable special crash kernel control page alloc policy. */ @@ -104,12 +85,23 @@ out_free_image: } static int do_kexec_load(unsigned long entry, unsigned long nr_segments, - struct kexec_segment __user *segments, unsigned long flags) + struct kexec_segment *segments, unsigned long flags) { struct kimage **dest_image, *image; unsigned long i; int ret; + /* + * Because we write directly to the reserved memory region when loading + * crash kernels we need a mutex here to prevent multiple crash kernels + * from attempting to load simultaneously, and to prevent a crash kernel + * from loading over the top of a in use crash kernel. + * + * KISS: always take the mutex. + */ + if (!mutex_trylock(&kexec_mutex)) + return -EBUSY; + if (flags & KEXEC_ON_CRASH) { dest_image = &kexec_crash_image; if (kexec_crash_image) @@ -121,7 +113,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, if (nr_segments == 0) { /* Uninstall image */ kimage_free(xchg(dest_image, NULL)); - return 0; + ret = 0; + goto out_unlock; } if (flags & KEXEC_ON_CRASH) { /* @@ -134,7 +127,7 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, ret = kimage_alloc_init(&image, entry, nr_segments, segments, flags); if (ret) - return ret; + goto out_unlock; if (flags & KEXEC_PRESERVE_CONTEXT) image->preserve_context = 1; @@ -171,6 +164,8 @@ out: arch_kexec_protect_crashkres(); kimage_free(image); +out_unlock: + mutex_unlock(&kexec_mutex); return ret; } @@ -236,7 +231,8 @@ static inline int kexec_load_check(unsigned long nr_segments, SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, struct kexec_segment __user *, segments, unsigned long, flags) { - int result; + struct kexec_segment *ksegments; + unsigned long result; result = kexec_load_check(nr_segments, flags); if (result) @@ -247,20 +243,12 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT)) return -EINVAL; - /* Because we write directly to the reserved memory - * region when loading crash kernels we need a mutex here to - * prevent multiple crash kernels from attempting to load - * simultaneously, and to prevent a crash kernel from loading - * over the top of a in use crash kernel. - * - * KISS: always take the mutex. - */ - if (!mutex_trylock(&kexec_mutex)) - return -EBUSY; + ksegments = memdup_user(segments, nr_segments * sizeof(ksegments[0])); + if (IS_ERR(ksegments)) + return PTR_ERR(ksegments); - result = do_kexec_load(entry, nr_segments, segments, flags); - - mutex_unlock(&kexec_mutex); + result = do_kexec_load(entry, nr_segments, ksegments, flags); + kfree(ksegments); return result; } @@ -272,7 +260,7 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry, compat_ulong_t, flags) { struct compat_kexec_segment in; - struct kexec_segment out, __user *ksegments; + struct kexec_segment *ksegments; unsigned long i, result; result = kexec_load_check(nr_segments, flags); @@ -285,37 +273,26 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry, if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT) return -EINVAL; - ksegments = compat_alloc_user_space(nr_segments * sizeof(out)); + ksegments = kmalloc_array(nr_segments, sizeof(ksegments[0]), + GFP_KERNEL); + if (!ksegments) + return -ENOMEM; + for (i = 0; i < nr_segments; i++) { result = copy_from_user(&in, &segments[i], sizeof(in)); if (result) - return -EFAULT; + goto fail; - out.buf = compat_ptr(in.buf); - out.bufsz = in.bufsz; - out.mem = in.mem; - out.memsz = in.memsz; - - result = copy_to_user(&ksegments[i], &out, sizeof(out)); - if (result) - return -EFAULT; + ksegments[i].buf = compat_ptr(in.buf); + ksegments[i].bufsz = in.bufsz; + ksegments[i].mem = in.mem; + ksegments[i].memsz = in.memsz; } - /* Because we write directly to the reserved memory - * region when loading crash kernels we need a mutex here to - * prevent multiple crash kernels from attempting to load - * simultaneously, and to prevent a crash kernel from loading - * over the top of a in use crash kernel. - * - * KISS: always take the mutex. - */ - if (!mutex_trylock(&kexec_mutex)) - return -EBUSY; - result = do_kexec_load(entry, nr_segments, ksegments, flags); - mutex_unlock(&kexec_mutex); - +fail: + kfree(ksegments); return result; } #endif diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 4b34a9aa32bc..5a5d192a89ac 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -979,7 +979,6 @@ void crash_kexec(struct pt_regs *regs) old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); if (old_cpu == PANIC_CPU_INVALID) { /* This is the 1st CPU which comes here, so go ahead. */ - printk_safe_flush_on_panic(); __crash_kexec(regs); /* diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 3a4beb9395c4..291b857a6e20 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -411,7 +411,7 @@ void klp_try_complete_transition(void) /* * Ditto for the idle "swapper" tasks. */ - get_online_cpus(); + cpus_read_lock(); for_each_possible_cpu(cpu) { task = idle_task(cpu); if (cpu_online(cpu)) { @@ -423,7 +423,7 @@ void klp_try_complete_transition(void) task->patch_state = klp_target_state; } } - put_online_cpus(); + cpus_read_unlock(); if (!complete) { if (klp_signals_cnt && !(klp_signals_cnt % SIGNALS_TIMEOUT)) diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 3572808223e4..d51cabf28f38 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -24,7 +24,8 @@ obj-$(CONFIG_SMP) += spinlock.o obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o -obj-$(CONFIG_RT_MUTEXES) += rtmutex.o +obj-$(CONFIG_RT_MUTEXES) += rtmutex_api.o +obj-$(CONFIG_PREEMPT_RT) += spinlock_rt.o ww_rt_mutex.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index b3adb40549bf..7c5a4a087cc7 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -59,7 +59,7 @@ static struct task_struct **writer_tasks; static struct task_struct **reader_tasks; static bool lock_is_write_held; -static bool lock_is_read_held; +static atomic_t lock_is_read_held; static unsigned long last_lock_release; struct lock_stress_stats { @@ -682,7 +682,7 @@ static int lock_torture_writer(void *arg) if (WARN_ON_ONCE(lock_is_write_held)) lwsp->n_lock_fail++; lock_is_write_held = true; - if (WARN_ON_ONCE(lock_is_read_held)) + if (WARN_ON_ONCE(atomic_read(&lock_is_read_held))) lwsp->n_lock_fail++; /* rare, but... */ lwsp->n_lock_acquired++; @@ -717,13 +717,13 @@ static int lock_torture_reader(void *arg) schedule_timeout_uninterruptible(1); cxt.cur_ops->readlock(tid); - lock_is_read_held = true; + atomic_inc(&lock_is_read_held); if (WARN_ON_ONCE(lock_is_write_held)) lrsp->n_lock_fail++; /* rare, but... */ lrsp->n_lock_acquired++; cxt.cur_ops->read_delay(&rand); - lock_is_read_held = false; + atomic_dec(&lock_is_read_held); cxt.cur_ops->readunlock(tid); stutter_wait("lock_torture_reader"); @@ -738,20 +738,22 @@ static int lock_torture_reader(void *arg) static void __torture_print_stats(char *page, struct lock_stress_stats *statp, bool write) { + long cur; bool fail = false; int i, n_stress; - long max = 0, min = statp ? statp[0].n_lock_acquired : 0; + long max = 0, min = statp ? data_race(statp[0].n_lock_acquired) : 0; long long sum = 0; n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; for (i = 0; i < n_stress; i++) { - if (statp[i].n_lock_fail) + if (data_race(statp[i].n_lock_fail)) fail = true; - sum += statp[i].n_lock_acquired; - if (max < statp[i].n_lock_acquired) - max = statp[i].n_lock_acquired; - if (min > statp[i].n_lock_acquired) - min = statp[i].n_lock_acquired; + cur = data_race(statp[i].n_lock_acquired); + sum += cur; + if (max < cur) + max = cur; + if (min > cur) + min = cur; } page += sprintf(page, "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", @@ -996,7 +998,6 @@ static int __init lock_torture_init(void) } if (nreaders_stress) { - lock_is_read_held = false; cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress, sizeof(*cxt.lrsa), GFP_KERNEL); diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c index db9301591e3f..bc8abb8549d2 100644 --- a/kernel/locking/mutex-debug.c +++ b/kernel/locking/mutex-debug.c @@ -1,6 +1,4 @@ /* - * kernel/mutex-debug.c - * * Debugging code for mutexes * * Started by Ingo Molnar: @@ -22,7 +20,7 @@ #include <linux/interrupt.h> #include <linux/debug_locks.h> -#include "mutex-debug.h" +#include "mutex.h" /* * Must be called with lock->wait_lock held. @@ -32,6 +30,7 @@ void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); + waiter->ww_ctx = MUTEX_POISON_WW_CTX; } void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) diff --git a/kernel/locking/mutex-debug.h b/kernel/locking/mutex-debug.h deleted file mode 100644 index 53e631e1d76d..000000000000 --- a/kernel/locking/mutex-debug.h +++ /dev/null @@ -1,29 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Mutexes: blocking mutual exclusion locks - * - * started by Ingo Molnar: - * - * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> - * - * This file contains mutex debugging related internal declarations, - * prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case. - * More details are in kernel/mutex-debug.c. - */ - -/* - * This must be called with lock->wait_lock held. - */ -extern void debug_mutex_lock_common(struct mutex *lock, - struct mutex_waiter *waiter); -extern void debug_mutex_wake_waiter(struct mutex *lock, - struct mutex_waiter *waiter); -extern void debug_mutex_free_waiter(struct mutex_waiter *waiter); -extern void debug_mutex_add_waiter(struct mutex *lock, - struct mutex_waiter *waiter, - struct task_struct *task); -extern void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, - struct task_struct *task); -extern void debug_mutex_unlock(struct mutex *lock); -extern void debug_mutex_init(struct mutex *lock, const char *name, - struct lock_class_key *key); diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index d2df5e68b503..d456579d0952 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -30,17 +30,20 @@ #include <linux/debug_locks.h> #include <linux/osq_lock.h> +#ifndef CONFIG_PREEMPT_RT +#include "mutex.h" + #ifdef CONFIG_DEBUG_MUTEXES -# include "mutex-debug.h" +# define MUTEX_WARN_ON(cond) DEBUG_LOCKS_WARN_ON(cond) #else -# include "mutex.h" +# define MUTEX_WARN_ON(cond) #endif void __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) { atomic_long_set(&lock->owner, 0); - spin_lock_init(&lock->wait_lock); + raw_spin_lock_init(&lock->wait_lock); INIT_LIST_HEAD(&lock->wait_list); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER osq_lock_init(&lock->osq); @@ -91,55 +94,56 @@ static inline unsigned long __owner_flags(unsigned long owner) return owner & MUTEX_FLAGS; } -/* - * Trylock variant that returns the owning task on failure. - */ -static inline struct task_struct *__mutex_trylock_or_owner(struct mutex *lock) +static inline struct task_struct *__mutex_trylock_common(struct mutex *lock, bool handoff) { unsigned long owner, curr = (unsigned long)current; owner = atomic_long_read(&lock->owner); for (;;) { /* must loop, can race against a flag */ - unsigned long old, flags = __owner_flags(owner); + unsigned long flags = __owner_flags(owner); unsigned long task = owner & ~MUTEX_FLAGS; if (task) { - if (likely(task != curr)) - break; - - if (likely(!(flags & MUTEX_FLAG_PICKUP))) + if (flags & MUTEX_FLAG_PICKUP) { + if (task != curr) + break; + flags &= ~MUTEX_FLAG_PICKUP; + } else if (handoff) { + if (flags & MUTEX_FLAG_HANDOFF) + break; + flags |= MUTEX_FLAG_HANDOFF; + } else { break; - - flags &= ~MUTEX_FLAG_PICKUP; + } } else { -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(flags & MUTEX_FLAG_PICKUP); -#endif + MUTEX_WARN_ON(flags & (MUTEX_FLAG_HANDOFF | MUTEX_FLAG_PICKUP)); + task = curr; } - /* - * We set the HANDOFF bit, we must make sure it doesn't live - * past the point where we acquire it. This would be possible - * if we (accidentally) set the bit on an unlocked mutex. - */ - flags &= ~MUTEX_FLAG_HANDOFF; - - old = atomic_long_cmpxchg_acquire(&lock->owner, owner, curr | flags); - if (old == owner) - return NULL; - - owner = old; + if (atomic_long_try_cmpxchg_acquire(&lock->owner, &owner, task | flags)) { + if (task == curr) + return NULL; + break; + } } return __owner_task(owner); } /* + * Trylock or set HANDOFF + */ +static inline bool __mutex_trylock_or_handoff(struct mutex *lock, bool handoff) +{ + return !__mutex_trylock_common(lock, handoff); +} + +/* * Actual trylock that will work on any unlocked state. */ static inline bool __mutex_trylock(struct mutex *lock) { - return !__mutex_trylock_or_owner(lock); + return !__mutex_trylock_common(lock, false); } #ifndef CONFIG_DEBUG_LOCK_ALLOC @@ -168,10 +172,7 @@ static __always_inline bool __mutex_unlock_fast(struct mutex *lock) { unsigned long curr = (unsigned long)current; - if (atomic_long_cmpxchg_release(&lock->owner, curr, 0UL) == curr) - return true; - - return false; + return atomic_long_try_cmpxchg_release(&lock->owner, &curr, 0UL); } #endif @@ -226,23 +227,18 @@ static void __mutex_handoff(struct mutex *lock, struct task_struct *task) unsigned long owner = atomic_long_read(&lock->owner); for (;;) { - unsigned long old, new; + unsigned long new; -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(__owner_task(owner) != current); - DEBUG_LOCKS_WARN_ON(owner & MUTEX_FLAG_PICKUP); -#endif + MUTEX_WARN_ON(__owner_task(owner) != current); + MUTEX_WARN_ON(owner & MUTEX_FLAG_PICKUP); new = (owner & MUTEX_FLAG_WAITERS); new |= (unsigned long)task; if (task) new |= MUTEX_FLAG_PICKUP; - old = atomic_long_cmpxchg_release(&lock->owner, owner, new); - if (old == owner) + if (atomic_long_try_cmpxchg_release(&lock->owner, &owner, new)) break; - - owner = old; } } @@ -286,218 +282,18 @@ void __sched mutex_lock(struct mutex *lock) EXPORT_SYMBOL(mutex_lock); #endif -/* - * Wait-Die: - * The newer transactions are killed when: - * It (the new transaction) makes a request for a lock being held - * by an older transaction. - * - * Wound-Wait: - * The newer transactions are wounded when: - * An older transaction makes a request for a lock being held by - * the newer transaction. - */ - -/* - * Associate the ww_mutex @ww with the context @ww_ctx under which we acquired - * it. - */ -static __always_inline void -ww_mutex_lock_acquired(struct ww_mutex *ww, struct ww_acquire_ctx *ww_ctx) -{ -#ifdef CONFIG_DEBUG_MUTEXES - /* - * If this WARN_ON triggers, you used ww_mutex_lock to acquire, - * but released with a normal mutex_unlock in this call. - * - * This should never happen, always use ww_mutex_unlock. - */ - DEBUG_LOCKS_WARN_ON(ww->ctx); - - /* - * Not quite done after calling ww_acquire_done() ? - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire); +#include "ww_mutex.h" - if (ww_ctx->contending_lock) { - /* - * After -EDEADLK you tried to - * acquire a different ww_mutex? Bad! - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww); - - /* - * You called ww_mutex_lock after receiving -EDEADLK, - * but 'forgot' to unlock everything else first? - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0); - ww_ctx->contending_lock = NULL; - } - - /* - * Naughty, using a different class will lead to undefined behavior! - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class); -#endif - ww_ctx->acquired++; - ww->ctx = ww_ctx; -} - -/* - * Determine if context @a is 'after' context @b. IOW, @a is a younger - * transaction than @b and depending on algorithm either needs to wait for - * @b or die. - */ -static inline bool __sched -__ww_ctx_stamp_after(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b) -{ - - return (signed long)(a->stamp - b->stamp) > 0; -} - -/* - * Wait-Die; wake a younger waiter context (when locks held) such that it can - * die. - * - * Among waiters with context, only the first one can have other locks acquired - * already (ctx->acquired > 0), because __ww_mutex_add_waiter() and - * __ww_mutex_check_kill() wake any but the earliest context. - */ -static bool __sched -__ww_mutex_die(struct mutex *lock, struct mutex_waiter *waiter, - struct ww_acquire_ctx *ww_ctx) -{ - if (!ww_ctx->is_wait_die) - return false; - - if (waiter->ww_ctx->acquired > 0 && - __ww_ctx_stamp_after(waiter->ww_ctx, ww_ctx)) { - debug_mutex_wake_waiter(lock, waiter); - wake_up_process(waiter->task); - } - - return true; -} - -/* - * Wound-Wait; wound a younger @hold_ctx if it holds the lock. - * - * Wound the lock holder if there are waiters with older transactions than - * the lock holders. Even if multiple waiters may wound the lock holder, - * it's sufficient that only one does. - */ -static bool __ww_mutex_wound(struct mutex *lock, - struct ww_acquire_ctx *ww_ctx, - struct ww_acquire_ctx *hold_ctx) -{ - struct task_struct *owner = __mutex_owner(lock); - - lockdep_assert_held(&lock->wait_lock); - - /* - * Possible through __ww_mutex_add_waiter() when we race with - * ww_mutex_set_context_fastpath(). In that case we'll get here again - * through __ww_mutex_check_waiters(). - */ - if (!hold_ctx) - return false; - - /* - * Can have !owner because of __mutex_unlock_slowpath(), but if owner, - * it cannot go away because we'll have FLAG_WAITERS set and hold - * wait_lock. - */ - if (!owner) - return false; - - if (ww_ctx->acquired > 0 && __ww_ctx_stamp_after(hold_ctx, ww_ctx)) { - hold_ctx->wounded = 1; - - /* - * wake_up_process() paired with set_current_state() - * inserts sufficient barriers to make sure @owner either sees - * it's wounded in __ww_mutex_check_kill() or has a - * wakeup pending to re-read the wounded state. - */ - if (owner != current) - wake_up_process(owner); - - return true; - } - - return false; -} - -/* - * We just acquired @lock under @ww_ctx, if there are later contexts waiting - * behind us on the wait-list, check if they need to die, or wound us. - * - * See __ww_mutex_add_waiter() for the list-order construction; basically the - * list is ordered by stamp, smallest (oldest) first. - * - * This relies on never mixing wait-die/wound-wait on the same wait-list; - * which is currently ensured by that being a ww_class property. - * - * The current task must not be on the wait list. - */ -static void __sched -__ww_mutex_check_waiters(struct mutex *lock, struct ww_acquire_ctx *ww_ctx) -{ - struct mutex_waiter *cur; - - lockdep_assert_held(&lock->wait_lock); - - list_for_each_entry(cur, &lock->wait_list, list) { - if (!cur->ww_ctx) - continue; - - if (__ww_mutex_die(lock, cur, ww_ctx) || - __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx)) - break; - } -} +#ifdef CONFIG_MUTEX_SPIN_ON_OWNER /* - * After acquiring lock with fastpath, where we do not hold wait_lock, set ctx - * and wake up any waiters so they can recheck. + * Trylock variant that returns the owning task on failure. */ -static __always_inline void -ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +static inline struct task_struct *__mutex_trylock_or_owner(struct mutex *lock) { - ww_mutex_lock_acquired(lock, ctx); - - /* - * The lock->ctx update should be visible on all cores before - * the WAITERS check is done, otherwise contended waiters might be - * missed. The contended waiters will either see ww_ctx == NULL - * and keep spinning, or it will acquire wait_lock, add itself - * to waiter list and sleep. - */ - smp_mb(); /* See comments above and below. */ - - /* - * [W] ww->ctx = ctx [W] MUTEX_FLAG_WAITERS - * MB MB - * [R] MUTEX_FLAG_WAITERS [R] ww->ctx - * - * The memory barrier above pairs with the memory barrier in - * __ww_mutex_add_waiter() and makes sure we either observe ww->ctx - * and/or !empty list. - */ - if (likely(!(atomic_long_read(&lock->base.owner) & MUTEX_FLAG_WAITERS))) - return; - - /* - * Uh oh, we raced in fastpath, check if any of the waiters need to - * die or wound us. - */ - spin_lock(&lock->base.wait_lock); - __ww_mutex_check_waiters(&lock->base, ctx); - spin_unlock(&lock->base.wait_lock); + return __mutex_trylock_common(lock, false); } -#ifdef CONFIG_MUTEX_SPIN_ON_OWNER - static inline bool ww_mutex_spin_on_owner(struct mutex *lock, struct ww_acquire_ctx *ww_ctx, struct mutex_waiter *waiter) @@ -754,171 +550,11 @@ EXPORT_SYMBOL(mutex_unlock); */ void __sched ww_mutex_unlock(struct ww_mutex *lock) { - /* - * The unlocking fastpath is the 0->1 transition from 'locked' - * into 'unlocked' state: - */ - if (lock->ctx) { -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired); -#endif - if (lock->ctx->acquired > 0) - lock->ctx->acquired--; - lock->ctx = NULL; - } - + __ww_mutex_unlock(lock); mutex_unlock(&lock->base); } EXPORT_SYMBOL(ww_mutex_unlock); - -static __always_inline int __sched -__ww_mutex_kill(struct mutex *lock, struct ww_acquire_ctx *ww_ctx) -{ - if (ww_ctx->acquired > 0) { -#ifdef CONFIG_DEBUG_MUTEXES - struct ww_mutex *ww; - - ww = container_of(lock, struct ww_mutex, base); - DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock); - ww_ctx->contending_lock = ww; -#endif - return -EDEADLK; - } - - return 0; -} - - -/* - * Check the wound condition for the current lock acquire. - * - * Wound-Wait: If we're wounded, kill ourself. - * - * Wait-Die: If we're trying to acquire a lock already held by an older - * context, kill ourselves. - * - * Since __ww_mutex_add_waiter() orders the wait-list on stamp, we only have to - * look at waiters before us in the wait-list. - */ -static inline int __sched -__ww_mutex_check_kill(struct mutex *lock, struct mutex_waiter *waiter, - struct ww_acquire_ctx *ctx) -{ - struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); - struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx); - struct mutex_waiter *cur; - - if (ctx->acquired == 0) - return 0; - - if (!ctx->is_wait_die) { - if (ctx->wounded) - return __ww_mutex_kill(lock, ctx); - - return 0; - } - - if (hold_ctx && __ww_ctx_stamp_after(ctx, hold_ctx)) - return __ww_mutex_kill(lock, ctx); - - /* - * If there is a waiter in front of us that has a context, then its - * stamp is earlier than ours and we must kill ourself. - */ - cur = waiter; - list_for_each_entry_continue_reverse(cur, &lock->wait_list, list) { - if (!cur->ww_ctx) - continue; - - return __ww_mutex_kill(lock, ctx); - } - - return 0; -} - -/* - * Add @waiter to the wait-list, keep the wait-list ordered by stamp, smallest - * first. Such that older contexts are preferred to acquire the lock over - * younger contexts. - * - * Waiters without context are interspersed in FIFO order. - * - * Furthermore, for Wait-Die kill ourself immediately when possible (there are - * older contexts already waiting) to avoid unnecessary waiting and for - * Wound-Wait ensure we wound the owning context when it is younger. - */ -static inline int __sched -__ww_mutex_add_waiter(struct mutex_waiter *waiter, - struct mutex *lock, - struct ww_acquire_ctx *ww_ctx) -{ - struct mutex_waiter *cur; - struct list_head *pos; - bool is_wait_die; - - if (!ww_ctx) { - __mutex_add_waiter(lock, waiter, &lock->wait_list); - return 0; - } - - is_wait_die = ww_ctx->is_wait_die; - - /* - * Add the waiter before the first waiter with a higher stamp. - * Waiters without a context are skipped to avoid starving - * them. Wait-Die waiters may die here. Wound-Wait waiters - * never die here, but they are sorted in stamp order and - * may wound the lock holder. - */ - pos = &lock->wait_list; - list_for_each_entry_reverse(cur, &lock->wait_list, list) { - if (!cur->ww_ctx) - continue; - - if (__ww_ctx_stamp_after(ww_ctx, cur->ww_ctx)) { - /* - * Wait-Die: if we find an older context waiting, there - * is no point in queueing behind it, as we'd have to - * die the moment it would acquire the lock. - */ - if (is_wait_die) { - int ret = __ww_mutex_kill(lock, ww_ctx); - - if (ret) - return ret; - } - - break; - } - - pos = &cur->list; - - /* Wait-Die: ensure younger waiters die. */ - __ww_mutex_die(lock, cur, ww_ctx); - } - - __mutex_add_waiter(lock, waiter, pos); - - /* - * Wound-Wait: if we're blocking on a mutex owned by a younger context, - * wound that such that we might proceed. - */ - if (!is_wait_die) { - struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); - - /* - * See ww_mutex_set_context_fastpath(). Orders setting - * MUTEX_FLAG_WAITERS vs the ww->ctx load, - * such that either we or the fastpath will wound @ww->ctx. - */ - smp_mb(); - __ww_mutex_wound(lock, ww_ctx, ww->ctx); - } - - return 0; -} - /* * Lock a mutex (possibly interruptible), slowpath: */ @@ -928,7 +564,6 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx) { struct mutex_waiter waiter; - bool first = false; struct ww_mutex *ww; int ret; @@ -937,9 +572,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas might_sleep(); -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(lock->magic != lock); -#endif + MUTEX_WARN_ON(lock->magic != lock); ww = container_of(lock, struct ww_mutex, base); if (ww_ctx) { @@ -953,6 +586,10 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas */ if (ww_ctx->acquired == 0) ww_ctx->wounded = 0; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + nest_lock = &ww_ctx->dep_map; +#endif } preempt_disable(); @@ -968,7 +605,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas return 0; } - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); /* * After waiting to acquire the wait_lock, try again. */ @@ -980,17 +617,15 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas } debug_mutex_lock_common(lock, &waiter); + waiter.task = current; + if (use_ww_ctx) + waiter.ww_ctx = ww_ctx; lock_contended(&lock->dep_map, ip); if (!use_ww_ctx) { /* add waiting tasks to the end of the waitqueue (FIFO): */ __mutex_add_waiter(lock, &waiter, &lock->wait_list); - - -#ifdef CONFIG_DEBUG_MUTEXES - waiter.ww_ctx = MUTEX_POISON_WW_CTX; -#endif } else { /* * Add in stamp order, waking up waiters that must kill @@ -999,14 +634,12 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas ret = __ww_mutex_add_waiter(&waiter, lock, ww_ctx); if (ret) goto err_early_kill; - - waiter.ww_ctx = ww_ctx; } - waiter.task = current; - set_current_state(state); for (;;) { + bool first; + /* * Once we hold wait_lock, we're serialized against * mutex_unlock() handing the lock off to us, do a trylock @@ -1032,18 +665,10 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas goto err; } - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); schedule_preempt_disabled(); - /* - * ww_mutex needs to always recheck its position since its waiter - * list is not FIFO ordered. - */ - if (ww_ctx || !first) { - first = __mutex_waiter_is_first(lock, &waiter); - if (first) - __mutex_set_flag(lock, MUTEX_FLAG_HANDOFF); - } + first = __mutex_waiter_is_first(lock, &waiter); set_current_state(state); /* @@ -1051,13 +676,13 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas * state back to RUNNING and fall through the next schedule(), * or we must see its unlock and acquire. */ - if (__mutex_trylock(lock) || + if (__mutex_trylock_or_handoff(lock, first) || (first && mutex_optimistic_spin(lock, ww_ctx, &waiter))) break; - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); } - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); acquired: __set_current_state(TASK_RUNNING); @@ -1082,7 +707,7 @@ skip_wait: if (ww_ctx) ww_mutex_lock_acquired(ww, ww_ctx); - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); preempt_enable(); return 0; @@ -1090,7 +715,7 @@ err: __set_current_state(TASK_RUNNING); __mutex_remove_waiter(lock, &waiter); err_early_kill: - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); debug_mutex_free_waiter(&waiter); mutex_release(&lock->dep_map, ip); preempt_enable(); @@ -1106,10 +731,9 @@ __mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass, static int __sched __ww_mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass, - struct lockdep_map *nest_lock, unsigned long ip, - struct ww_acquire_ctx *ww_ctx) + unsigned long ip, struct ww_acquire_ctx *ww_ctx) { - return __mutex_lock_common(lock, state, subclass, nest_lock, ip, ww_ctx, true); + return __mutex_lock_common(lock, state, subclass, NULL, ip, ww_ctx, true); } #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -1189,8 +813,7 @@ ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) might_sleep(); ret = __ww_mutex_lock(&lock->base, TASK_UNINTERRUPTIBLE, - 0, ctx ? &ctx->dep_map : NULL, _RET_IP_, - ctx); + 0, _RET_IP_, ctx); if (!ret && ctx && ctx->acquired > 1) return ww_mutex_deadlock_injection(lock, ctx); @@ -1205,8 +828,7 @@ ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) might_sleep(); ret = __ww_mutex_lock(&lock->base, TASK_INTERRUPTIBLE, - 0, ctx ? &ctx->dep_map : NULL, _RET_IP_, - ctx); + 0, _RET_IP_, ctx); if (!ret && ctx && ctx->acquired > 1) return ww_mutex_deadlock_injection(lock, ctx); @@ -1237,29 +859,21 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne */ owner = atomic_long_read(&lock->owner); for (;;) { - unsigned long old; - -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(__owner_task(owner) != current); - DEBUG_LOCKS_WARN_ON(owner & MUTEX_FLAG_PICKUP); -#endif + MUTEX_WARN_ON(__owner_task(owner) != current); + MUTEX_WARN_ON(owner & MUTEX_FLAG_PICKUP); if (owner & MUTEX_FLAG_HANDOFF) break; - old = atomic_long_cmpxchg_release(&lock->owner, owner, - __owner_flags(owner)); - if (old == owner) { + if (atomic_long_try_cmpxchg_release(&lock->owner, &owner, __owner_flags(owner))) { if (owner & MUTEX_FLAG_WAITERS) break; return; } - - owner = old; } - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); debug_mutex_unlock(lock); if (!list_empty(&lock->wait_list)) { /* get the first entry from the wait-list: */ @@ -1276,7 +890,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne if (owner & MUTEX_FLAG_HANDOFF) __mutex_handoff(lock, next); - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); wake_up_q(&wake_q); } @@ -1380,7 +994,7 @@ __mutex_lock_interruptible_slowpath(struct mutex *lock) static noinline int __sched __ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { - return __ww_mutex_lock(&lock->base, TASK_UNINTERRUPTIBLE, 0, NULL, + return __ww_mutex_lock(&lock->base, TASK_UNINTERRUPTIBLE, 0, _RET_IP_, ctx); } @@ -1388,7 +1002,7 @@ static noinline int __sched __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { - return __ww_mutex_lock(&lock->base, TASK_INTERRUPTIBLE, 0, NULL, + return __ww_mutex_lock(&lock->base, TASK_INTERRUPTIBLE, 0, _RET_IP_, ctx); } @@ -1412,9 +1026,7 @@ int __sched mutex_trylock(struct mutex *lock) { bool locked; -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(lock->magic != lock); -#endif + MUTEX_WARN_ON(lock->magic != lock); locked = __mutex_trylock(lock); if (locked) @@ -1455,7 +1067,8 @@ ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) } EXPORT_SYMBOL(ww_mutex_lock_interruptible); -#endif +#endif /* !CONFIG_DEBUG_LOCK_ALLOC */ +#endif /* !CONFIG_PREEMPT_RT */ /** * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0 diff --git a/kernel/locking/mutex.h b/kernel/locking/mutex.h index f0c710b1d192..0b2a79c4013b 100644 --- a/kernel/locking/mutex.h +++ b/kernel/locking/mutex.h @@ -5,19 +5,41 @@ * started by Ingo Molnar: * * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> - * - * This file contains mutex debugging related internal prototypes, for the - * !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs: */ -#define debug_mutex_wake_waiter(lock, waiter) do { } while (0) -#define debug_mutex_free_waiter(waiter) do { } while (0) -#define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0) -#define debug_mutex_remove_waiter(lock, waiter, ti) do { } while (0) -#define debug_mutex_unlock(lock) do { } while (0) -#define debug_mutex_init(lock, name, key) do { } while (0) +/* + * This is the control structure for tasks blocked on mutex, which resides + * on the blocked task's kernel stack: + */ +struct mutex_waiter { + struct list_head list; + struct task_struct *task; + struct ww_acquire_ctx *ww_ctx; +#ifdef CONFIG_DEBUG_MUTEXES + void *magic; +#endif +}; -static inline void -debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) -{ -} +#ifdef CONFIG_DEBUG_MUTEXES +extern void debug_mutex_lock_common(struct mutex *lock, + struct mutex_waiter *waiter); +extern void debug_mutex_wake_waiter(struct mutex *lock, + struct mutex_waiter *waiter); +extern void debug_mutex_free_waiter(struct mutex_waiter *waiter); +extern void debug_mutex_add_waiter(struct mutex *lock, + struct mutex_waiter *waiter, + struct task_struct *task); +extern void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, + struct task_struct *task); +extern void debug_mutex_unlock(struct mutex *lock); +extern void debug_mutex_init(struct mutex *lock, const char *name, + struct lock_class_key *key); +#else /* CONFIG_DEBUG_MUTEXES */ +# define debug_mutex_lock_common(lock, waiter) do { } while (0) +# define debug_mutex_wake_waiter(lock, waiter) do { } while (0) +# define debug_mutex_free_waiter(waiter) do { } while (0) +# define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0) +# define debug_mutex_remove_waiter(lock, waiter, ti) do { } while (0) +# define debug_mutex_unlock(lock) do { } while (0) +# define debug_mutex_init(lock, name, key) do { } while (0) +#endif /* !CONFIG_DEBUG_MUTEXES */ diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index ad0db322ed3b..6bb116c559b4 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -8,20 +8,58 @@ * Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com> * Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt * Copyright (C) 2006 Esben Nielsen + * Adaptive Spinlocks: + * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich, + * and Peter Morreale, + * Adaptive Spinlocks simplification: + * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com> * * See Documentation/locking/rt-mutex-design.rst for details. */ -#include <linux/spinlock.h> -#include <linux/export.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/sched/deadline.h> #include <linux/sched/signal.h> #include <linux/sched/rt.h> -#include <linux/sched/deadline.h> #include <linux/sched/wake_q.h> -#include <linux/sched/debug.h> -#include <linux/timer.h> +#include <linux/ww_mutex.h> #include "rtmutex_common.h" +#ifndef WW_RT +# define build_ww_mutex() (false) +# define ww_container_of(rtm) NULL + +static inline int __ww_mutex_add_waiter(struct rt_mutex_waiter *waiter, + struct rt_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ + return 0; +} + +static inline void __ww_mutex_check_waiters(struct rt_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ +} + +static inline void ww_mutex_lock_acquired(struct ww_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ +} + +static inline int __ww_mutex_check_kill(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter, + struct ww_acquire_ctx *ww_ctx) +{ + return 0; +} + +#else +# define build_ww_mutex() (true) +# define ww_container_of(rtm) container_of(rtm, struct ww_mutex, base) +# include "ww_mutex.h" +#endif + /* * lock->owner state tracking: * @@ -50,7 +88,7 @@ */ static __always_inline void -rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner) +rt_mutex_set_owner(struct rt_mutex_base *lock, struct task_struct *owner) { unsigned long val = (unsigned long)owner; @@ -60,13 +98,13 @@ rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner) WRITE_ONCE(lock->owner, (struct task_struct *)val); } -static __always_inline void clear_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline void clear_rt_mutex_waiters(struct rt_mutex_base *lock) { lock->owner = (struct task_struct *) ((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS); } -static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex_base *lock) { unsigned long owner, *p = (unsigned long *) &lock->owner; @@ -141,15 +179,26 @@ static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex *lock) * set up. */ #ifndef CONFIG_DEBUG_RT_MUTEXES -# define rt_mutex_cmpxchg_acquire(l,c,n) (cmpxchg_acquire(&l->owner, c, n) == c) -# define rt_mutex_cmpxchg_release(l,c,n) (cmpxchg_release(&l->owner, c, n) == c) +static __always_inline bool rt_mutex_cmpxchg_acquire(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return try_cmpxchg_acquire(&lock->owner, &old, new); +} + +static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return try_cmpxchg_release(&lock->owner, &old, new); +} /* * Callers must hold the ->wait_lock -- which is the whole purpose as we force * all future threads that attempt to [Rmw] the lock to the slowpath. As such * relaxed semantics suffice. */ -static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline void mark_rt_mutex_waiters(struct rt_mutex_base *lock) { unsigned long owner, *p = (unsigned long *) &lock->owner; @@ -165,7 +214,7 @@ static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) * 2) Drop lock->wait_lock * 3) Try to unlock the lock with cmpxchg */ -static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, +static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex_base *lock, unsigned long flags) __releases(lock->wait_lock) { @@ -201,10 +250,22 @@ static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, } #else -# define rt_mutex_cmpxchg_acquire(l,c,n) (0) -# define rt_mutex_cmpxchg_release(l,c,n) (0) +static __always_inline bool rt_mutex_cmpxchg_acquire(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return false; + +} -static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return false; +} + +static __always_inline void mark_rt_mutex_waiters(struct rt_mutex_base *lock) { lock->owner = (struct task_struct *) ((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS); @@ -213,7 +274,7 @@ static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) /* * Simple slow path only version: lock->owner is protected by lock->wait_lock. */ -static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, +static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex_base *lock, unsigned long flags) __releases(lock->wait_lock) { @@ -223,11 +284,28 @@ static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, } #endif +static __always_inline int __waiter_prio(struct task_struct *task) +{ + int prio = task->prio; + + if (!rt_prio(prio)) + return DEFAULT_PRIO; + + return prio; +} + +static __always_inline void +waiter_update_prio(struct rt_mutex_waiter *waiter, struct task_struct *task) +{ + waiter->prio = __waiter_prio(task); + waiter->deadline = task->dl.deadline; +} + /* * Only use with rt_mutex_waiter_{less,equal}() */ #define task_to_waiter(p) \ - &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline } + &(struct rt_mutex_waiter){ .prio = __waiter_prio(p), .deadline = (p)->dl.deadline } static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, struct rt_mutex_waiter *right) @@ -265,22 +343,63 @@ static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left, return 1; } +static inline bool rt_mutex_steal(struct rt_mutex_waiter *waiter, + struct rt_mutex_waiter *top_waiter) +{ + if (rt_mutex_waiter_less(waiter, top_waiter)) + return true; + +#ifdef RT_MUTEX_BUILD_SPINLOCKS + /* + * Note that RT tasks are excluded from same priority (lateral) + * steals to prevent the introduction of an unbounded latency. + */ + if (rt_prio(waiter->prio) || dl_prio(waiter->prio)) + return false; + + return rt_mutex_waiter_equal(waiter, top_waiter); +#else + return false; +#endif +} + #define __node_2_waiter(node) \ rb_entry((node), struct rt_mutex_waiter, tree_entry) static __always_inline bool __waiter_less(struct rb_node *a, const struct rb_node *b) { - return rt_mutex_waiter_less(__node_2_waiter(a), __node_2_waiter(b)); + struct rt_mutex_waiter *aw = __node_2_waiter(a); + struct rt_mutex_waiter *bw = __node_2_waiter(b); + + if (rt_mutex_waiter_less(aw, bw)) + return 1; + + if (!build_ww_mutex()) + return 0; + + if (rt_mutex_waiter_less(bw, aw)) + return 0; + + /* NOTE: relies on waiter->ww_ctx being set before insertion */ + if (aw->ww_ctx) { + if (!bw->ww_ctx) + return 1; + + return (signed long)(aw->ww_ctx->stamp - + bw->ww_ctx->stamp) < 0; + } + + return 0; } static __always_inline void -rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter) +rt_mutex_enqueue(struct rt_mutex_base *lock, struct rt_mutex_waiter *waiter) { rb_add_cached(&waiter->tree_entry, &lock->waiters, __waiter_less); } static __always_inline void -rt_mutex_dequeue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter) +rt_mutex_dequeue(struct rt_mutex_base *lock, struct rt_mutex_waiter *waiter) { if (RB_EMPTY_NODE(&waiter->tree_entry)) return; @@ -326,6 +445,35 @@ static __always_inline void rt_mutex_adjust_prio(struct task_struct *p) rt_mutex_setprio(p, pi_task); } +/* RT mutex specific wake_q wrappers */ +static __always_inline void rt_mutex_wake_q_add(struct rt_wake_q_head *wqh, + struct rt_mutex_waiter *w) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && w->wake_state != TASK_NORMAL) { + if (IS_ENABLED(CONFIG_PROVE_LOCKING)) + WARN_ON_ONCE(wqh->rtlock_task); + get_task_struct(w->task); + wqh->rtlock_task = w->task; + } else { + wake_q_add(&wqh->head, w->task); + } +} + +static __always_inline void rt_mutex_wake_up_q(struct rt_wake_q_head *wqh) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && wqh->rtlock_task) { + wake_up_state(wqh->rtlock_task, TASK_RTLOCK_WAIT); + put_task_struct(wqh->rtlock_task); + wqh->rtlock_task = NULL; + } + + if (!wake_q_empty(&wqh->head)) + wake_up_q(&wqh->head); + + /* Pairs with preempt_disable() in mark_wakeup_next_waiter() */ + preempt_enable(); +} + /* * Deadlock detection is conditional: * @@ -348,12 +496,7 @@ rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter, return chwalk == RT_MUTEX_FULL_CHAINWALK; } -/* - * Max number of times we'll walk the boosting chain: - */ -int max_lock_depth = 1024; - -static __always_inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) +static __always_inline struct rt_mutex_base *task_blocked_on_lock(struct task_struct *p) { return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; } @@ -423,15 +566,15 @@ static __always_inline struct rt_mutex *task_blocked_on_lock(struct task_struct */ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, enum rtmutex_chainwalk chwalk, - struct rt_mutex *orig_lock, - struct rt_mutex *next_lock, + struct rt_mutex_base *orig_lock, + struct rt_mutex_base *next_lock, struct rt_mutex_waiter *orig_waiter, struct task_struct *top_task) { struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter; struct rt_mutex_waiter *prerequeue_top_waiter; int ret = 0, depth = 0; - struct rt_mutex *lock; + struct rt_mutex_base *lock; bool detect_deadlock; bool requeue = true; @@ -514,6 +657,31 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, goto out_unlock_pi; /* + * There could be 'spurious' loops in the lock graph due to ww_mutex, + * consider: + * + * P1: A, ww_A, ww_B + * P2: ww_B, ww_A + * P3: A + * + * P3 should not return -EDEADLK because it gets trapped in the cycle + * created by P1 and P2 (which will resolve -- and runs into + * max_lock_depth above). Therefore disable detect_deadlock such that + * the below termination condition can trigger once all relevant tasks + * are boosted. + * + * Even when we start with ww_mutex we can disable deadlock detection, + * since we would supress a ww_mutex induced deadlock at [6] anyway. + * Supressing it here however is not sufficient since we might still + * hit [6] due to adjustment driven iteration. + * + * NOTE: if someone were to create a deadlock between 2 ww_classes we'd + * utterly fail to report it; lockdep should. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && waiter->ww_ctx && detect_deadlock) + detect_deadlock = false; + + /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! @@ -574,8 +742,21 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * walk, we detected a deadlock. */ if (lock == orig_lock || rt_mutex_owner(lock) == top_task) { - raw_spin_unlock(&lock->wait_lock); ret = -EDEADLK; + + /* + * When the deadlock is due to ww_mutex; also see above. Don't + * report the deadlock and instead let the ww_mutex wound/die + * logic pick which of the contending threads gets -EDEADLK. + * + * NOTE: assumes the cycle only contains a single ww_class; any + * other configuration and we fail to report; also, see + * lockdep. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && orig_waiter && orig_waiter->ww_ctx) + ret = 0; + + raw_spin_unlock(&lock->wait_lock); goto out_unlock_pi; } @@ -653,8 +834,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * serializes all pi_waiters access and rb_erase() does not care about * the values of the node being removed. */ - waiter->prio = task->prio; - waiter->deadline = task->dl.deadline; + waiter_update_prio(waiter, task); rt_mutex_enqueue(lock, waiter); @@ -676,7 +856,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * to get the lock. */ if (prerequeue_top_waiter != rt_mutex_top_waiter(lock)) - wake_up_process(rt_mutex_top_waiter(lock)->task); + wake_up_state(waiter->task, waiter->wake_state); raw_spin_unlock_irq(&lock->wait_lock); return 0; } @@ -779,7 +959,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * callsite called task_blocked_on_lock(), otherwise NULL */ static int __sched -try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, +try_to_take_rt_mutex(struct rt_mutex_base *lock, struct task_struct *task, struct rt_mutex_waiter *waiter) { lockdep_assert_held(&lock->wait_lock); @@ -815,19 +995,21 @@ try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, * trylock attempt. */ if (waiter) { - /* - * If waiter is not the highest priority waiter of - * @lock, give up. - */ - if (waiter != rt_mutex_top_waiter(lock)) - return 0; + struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock); /* - * We can acquire the lock. Remove the waiter from the - * lock waiters tree. + * If waiter is the highest priority waiter of @lock, + * or allowed to steal it, take it over. */ - rt_mutex_dequeue(lock, waiter); - + if (waiter == top_waiter || rt_mutex_steal(waiter, top_waiter)) { + /* + * We can acquire the lock. Remove the waiter from the + * lock waiters tree. + */ + rt_mutex_dequeue(lock, waiter); + } else { + return 0; + } } else { /* * If the lock has waiters already we check whether @task is @@ -838,13 +1020,9 @@ try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, * not need to be dequeued. */ if (rt_mutex_has_waiters(lock)) { - /* - * If @task->prio is greater than or equal to - * the top waiter priority (kernel view), - * @task lost. - */ - if (!rt_mutex_waiter_less(task_to_waiter(task), - rt_mutex_top_waiter(lock))) + /* Check whether the trylock can steal it. */ + if (!rt_mutex_steal(task_to_waiter(task), + rt_mutex_top_waiter(lock))) return 0; /* @@ -897,14 +1075,15 @@ takeit: * * This must be called with lock->wait_lock held and interrupts disabled */ -static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, +static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock, struct rt_mutex_waiter *waiter, struct task_struct *task, + struct ww_acquire_ctx *ww_ctx, enum rtmutex_chainwalk chwalk) { struct task_struct *owner = rt_mutex_owner(lock); struct rt_mutex_waiter *top_waiter = waiter; - struct rt_mutex *next_lock; + struct rt_mutex_base *next_lock; int chain_walk = 0, res; lockdep_assert_held(&lock->wait_lock); @@ -924,8 +1103,7 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, raw_spin_lock(&task->pi_lock); waiter->task = task; waiter->lock = lock; - waiter->prio = task->prio; - waiter->deadline = task->dl.deadline; + waiter_update_prio(waiter, task); /* Get the top priority waiter on the lock */ if (rt_mutex_has_waiters(lock)) @@ -936,6 +1114,21 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, raw_spin_unlock(&task->pi_lock); + if (build_ww_mutex() && ww_ctx) { + struct rt_mutex *rtm; + + /* Check whether the waiter should back out immediately */ + rtm = container_of(lock, struct rt_mutex, rtmutex); + res = __ww_mutex_add_waiter(waiter, rtm, ww_ctx); + if (res) { + raw_spin_lock(&task->pi_lock); + rt_mutex_dequeue(lock, waiter); + task->pi_blocked_on = NULL; + raw_spin_unlock(&task->pi_lock); + return res; + } + } + if (!owner) return 0; @@ -986,8 +1179,8 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, * * Called with lock->wait_lock held and interrupts disabled. */ -static void __sched mark_wakeup_next_waiter(struct wake_q_head *wake_q, - struct rt_mutex *lock) +static void __sched mark_wakeup_next_waiter(struct rt_wake_q_head *wqh, + struct rt_mutex_base *lock) { struct rt_mutex_waiter *waiter; @@ -1023,235 +1216,14 @@ static void __sched mark_wakeup_next_waiter(struct wake_q_head *wake_q, * deboost but before waking our donor task, hence the preempt_disable() * before unlock. * - * Pairs with preempt_enable() in rt_mutex_postunlock(); + * Pairs with preempt_enable() in rt_mutex_wake_up_q(); */ preempt_disable(); - wake_q_add(wake_q, waiter->task); - raw_spin_unlock(¤t->pi_lock); -} - -/* - * Remove a waiter from a lock and give up - * - * Must be called with lock->wait_lock held and interrupts disabled. I must - * have just failed to try_to_take_rt_mutex(). - */ -static void __sched remove_waiter(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter) -{ - bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); - struct task_struct *owner = rt_mutex_owner(lock); - struct rt_mutex *next_lock; - - lockdep_assert_held(&lock->wait_lock); - - raw_spin_lock(¤t->pi_lock); - rt_mutex_dequeue(lock, waiter); - current->pi_blocked_on = NULL; + rt_mutex_wake_q_add(wqh, waiter); raw_spin_unlock(¤t->pi_lock); - - /* - * Only update priority if the waiter was the highest priority - * waiter of the lock and there is an owner to update. - */ - if (!owner || !is_top_waiter) - return; - - raw_spin_lock(&owner->pi_lock); - - rt_mutex_dequeue_pi(owner, waiter); - - if (rt_mutex_has_waiters(lock)) - rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock)); - - rt_mutex_adjust_prio(owner); - - /* Store the lock on which owner is blocked or NULL */ - next_lock = task_blocked_on_lock(owner); - - raw_spin_unlock(&owner->pi_lock); - - /* - * Don't walk the chain, if the owner task is not blocked - * itself. - */ - if (!next_lock) - return; - - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(owner); - - raw_spin_unlock_irq(&lock->wait_lock); - - rt_mutex_adjust_prio_chain(owner, RT_MUTEX_MIN_CHAINWALK, lock, - next_lock, NULL, current); - - raw_spin_lock_irq(&lock->wait_lock); -} - -/* - * Recheck the pi chain, in case we got a priority setting - * - * Called from sched_setscheduler - */ -void __sched rt_mutex_adjust_pi(struct task_struct *task) -{ - struct rt_mutex_waiter *waiter; - struct rt_mutex *next_lock; - unsigned long flags; - - raw_spin_lock_irqsave(&task->pi_lock, flags); - - waiter = task->pi_blocked_on; - if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { - raw_spin_unlock_irqrestore(&task->pi_lock, flags); - return; - } - next_lock = waiter->lock; - raw_spin_unlock_irqrestore(&task->pi_lock, flags); - - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(task); - - rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL, - next_lock, NULL, task); } -void __sched rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) -{ - debug_rt_mutex_init_waiter(waiter); - RB_CLEAR_NODE(&waiter->pi_tree_entry); - RB_CLEAR_NODE(&waiter->tree_entry); - waiter->task = NULL; -} - -/** - * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop - * @lock: the rt_mutex to take - * @state: the state the task should block in (TASK_INTERRUPTIBLE - * or TASK_UNINTERRUPTIBLE) - * @timeout: the pre-initialized and started timer, or NULL for none - * @waiter: the pre-initialized rt_mutex_waiter - * - * Must be called with lock->wait_lock held and interrupts disabled - */ -static int __sched __rt_mutex_slowlock(struct rt_mutex *lock, unsigned int state, - struct hrtimer_sleeper *timeout, - struct rt_mutex_waiter *waiter) -{ - int ret = 0; - - for (;;) { - /* Try to acquire the lock: */ - if (try_to_take_rt_mutex(lock, current, waiter)) - break; - - if (timeout && !timeout->task) { - ret = -ETIMEDOUT; - break; - } - if (signal_pending_state(state, current)) { - ret = -EINTR; - break; - } - - raw_spin_unlock_irq(&lock->wait_lock); - - schedule(); - - raw_spin_lock_irq(&lock->wait_lock); - set_current_state(state); - } - - __set_current_state(TASK_RUNNING); - return ret; -} - -static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, - struct rt_mutex_waiter *w) -{ - /* - * If the result is not -EDEADLOCK or the caller requested - * deadlock detection, nothing to do here. - */ - if (res != -EDEADLOCK || detect_deadlock) - return; - - /* - * Yell loudly and stop the task right here. - */ - WARN(1, "rtmutex deadlock detected\n"); - while (1) { - set_current_state(TASK_INTERRUPTIBLE); - schedule(); - } -} - -/* - * Slow path lock function: - */ -static int __sched rt_mutex_slowlock(struct rt_mutex *lock, unsigned int state, - struct hrtimer_sleeper *timeout, - enum rtmutex_chainwalk chwalk) -{ - struct rt_mutex_waiter waiter; - unsigned long flags; - int ret = 0; - - rt_mutex_init_waiter(&waiter); - - /* - * Technically we could use raw_spin_[un]lock_irq() here, but this can - * be called in early boot if the cmpxchg() fast path is disabled - * (debug, no architecture support). In this case we will acquire the - * rtmutex with lock->wait_lock held. But we cannot unconditionally - * enable interrupts in that early boot case. So we need to use the - * irqsave/restore variants. - */ - raw_spin_lock_irqsave(&lock->wait_lock, flags); - - /* Try to acquire the lock again: */ - if (try_to_take_rt_mutex(lock, current, NULL)) { - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - return 0; - } - - set_current_state(state); - - /* Setup the timer, when timeout != NULL */ - if (unlikely(timeout)) - hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); - - ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk); - - if (likely(!ret)) - /* sleep on the mutex */ - ret = __rt_mutex_slowlock(lock, state, timeout, &waiter); - - if (unlikely(ret)) { - __set_current_state(TASK_RUNNING); - remove_waiter(lock, &waiter); - rt_mutex_handle_deadlock(ret, chwalk, &waiter); - } - - /* - * try_to_take_rt_mutex() sets the waiter bit - * unconditionally. We might have to fix that up. - */ - fixup_rt_mutex_waiters(lock); - - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - - /* Remove pending timer: */ - if (unlikely(timeout)) - hrtimer_cancel(&timeout->timer); - - debug_rt_mutex_free_waiter(&waiter); - - return ret; -} - -static int __sched __rt_mutex_slowtrylock(struct rt_mutex *lock) +static int __sched __rt_mutex_slowtrylock(struct rt_mutex_base *lock) { int ret = try_to_take_rt_mutex(lock, current, NULL); @@ -1267,7 +1239,7 @@ static int __sched __rt_mutex_slowtrylock(struct rt_mutex *lock) /* * Slow path try-lock function: */ -static int __sched rt_mutex_slowtrylock(struct rt_mutex *lock) +static int __sched rt_mutex_slowtrylock(struct rt_mutex_base *lock) { unsigned long flags; int ret; @@ -1293,25 +1265,20 @@ static int __sched rt_mutex_slowtrylock(struct rt_mutex *lock) return ret; } -/* - * Performs the wakeup of the top-waiter and re-enables preemption. - */ -void __sched rt_mutex_postunlock(struct wake_q_head *wake_q) +static __always_inline int __rt_mutex_trylock(struct rt_mutex_base *lock) { - wake_up_q(wake_q); + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) + return 1; - /* Pairs with preempt_disable() in mark_wakeup_next_waiter() */ - preempt_enable(); + return rt_mutex_slowtrylock(lock); } /* * Slow path to release a rt-mutex. - * - * Return whether the current task needs to call rt_mutex_postunlock(). */ -static void __sched rt_mutex_slowunlock(struct rt_mutex *lock) +static void __sched rt_mutex_slowunlock(struct rt_mutex_base *lock) { - DEFINE_WAKE_Q(wake_q); + DEFINE_RT_WAKE_Q(wqh); unsigned long flags; /* irqsave required to support early boot calls */ @@ -1364,422 +1331,387 @@ static void __sched rt_mutex_slowunlock(struct rt_mutex *lock) * * Queue the next waiter for wakeup once we release the wait_lock. */ - mark_wakeup_next_waiter(&wake_q, lock); + mark_wakeup_next_waiter(&wqh, lock); raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - rt_mutex_postunlock(&wake_q); + rt_mutex_wake_up_q(&wqh); } -/* - * debug aware fast / slowpath lock,trylock,unlock - * - * The atomic acquire/release ops are compiled away, when either the - * architecture does not support cmpxchg or when debugging is enabled. - */ -static __always_inline int __rt_mutex_lock(struct rt_mutex *lock, long state, - unsigned int subclass) +static __always_inline void __rt_mutex_unlock(struct rt_mutex_base *lock) { - int ret; - - might_sleep(); - mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); - - if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) - return 0; + if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) + return; - ret = rt_mutex_slowlock(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK); - if (ret) - mutex_release(&lock->dep_map, _RET_IP_); - return ret; + rt_mutex_slowunlock(lock); } -#ifdef CONFIG_DEBUG_LOCK_ALLOC -/** - * rt_mutex_lock_nested - lock a rt_mutex - * - * @lock: the rt_mutex to be locked - * @subclass: the lockdep subclass - */ -void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass) +#ifdef CONFIG_SMP +static bool rtmutex_spin_on_owner(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *owner) { - __rt_mutex_lock(lock, TASK_UNINTERRUPTIBLE, subclass); -} -EXPORT_SYMBOL_GPL(rt_mutex_lock_nested); - -#else /* !CONFIG_DEBUG_LOCK_ALLOC */ + bool res = true; -/** - * rt_mutex_lock - lock a rt_mutex - * - * @lock: the rt_mutex to be locked - */ -void __sched rt_mutex_lock(struct rt_mutex *lock) + rcu_read_lock(); + for (;;) { + /* If owner changed, trylock again. */ + if (owner != rt_mutex_owner(lock)) + break; + /* + * Ensure that @owner is dereferenced after checking that + * the lock owner still matches @owner. If that fails, + * @owner might point to freed memory. If it still matches, + * the rcu_read_lock() ensures the memory stays valid. + */ + barrier(); + /* + * Stop spinning when: + * - the lock owner has been scheduled out + * - current is not longer the top waiter + * - current is requested to reschedule (redundant + * for CONFIG_PREEMPT_RCU=y) + * - the VCPU on which owner runs is preempted + */ + if (!owner->on_cpu || need_resched() || + rt_mutex_waiter_is_top_waiter(lock, waiter) || + vcpu_is_preempted(task_cpu(owner))) { + res = false; + break; + } + cpu_relax(); + } + rcu_read_unlock(); + return res; +} +#else +static bool rtmutex_spin_on_owner(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *owner) { - __rt_mutex_lock(lock, TASK_UNINTERRUPTIBLE, 0); + return false; } -EXPORT_SYMBOL_GPL(rt_mutex_lock); #endif -/** - * rt_mutex_lock_interruptible - lock a rt_mutex interruptible - * - * @lock: the rt_mutex to be locked - * - * Returns: - * 0 on success - * -EINTR when interrupted by a signal +#ifdef RT_MUTEX_BUILD_MUTEX +/* + * Functions required for: + * - rtmutex, futex on all kernels + * - mutex and rwsem substitutions on RT kernels */ -int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock) -{ - return __rt_mutex_lock(lock, TASK_INTERRUPTIBLE, 0); -} -EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); -/** - * rt_mutex_trylock - try to lock a rt_mutex - * - * @lock: the rt_mutex to be locked - * - * This function can only be called in thread context. It's safe to call it - * from atomic regions, but not from hard or soft interrupt context. +/* + * Remove a waiter from a lock and give up * - * Returns: - * 1 on success - * 0 on contention + * Must be called with lock->wait_lock held and interrupts disabled. It must + * have just failed to try_to_take_rt_mutex(). */ -int __sched rt_mutex_trylock(struct rt_mutex *lock) +static void __sched remove_waiter(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter) { - int ret; + bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); + struct task_struct *owner = rt_mutex_owner(lock); + struct rt_mutex_base *next_lock; - if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) - return 0; + lockdep_assert_held(&lock->wait_lock); + + raw_spin_lock(¤t->pi_lock); + rt_mutex_dequeue(lock, waiter); + current->pi_blocked_on = NULL; + raw_spin_unlock(¤t->pi_lock); /* - * No lockdep annotation required because lockdep disables the fast - * path. + * Only update priority if the waiter was the highest priority + * waiter of the lock and there is an owner to update. */ - if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) - return 1; - - ret = rt_mutex_slowtrylock(lock); - if (ret) - mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); - - return ret; -} -EXPORT_SYMBOL_GPL(rt_mutex_trylock); - -/** - * rt_mutex_unlock - unlock a rt_mutex - * - * @lock: the rt_mutex to be unlocked - */ -void __sched rt_mutex_unlock(struct rt_mutex *lock) -{ - mutex_release(&lock->dep_map, _RET_IP_); - if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) + if (!owner || !is_top_waiter) return; - rt_mutex_slowunlock(lock); -} -EXPORT_SYMBOL_GPL(rt_mutex_unlock); + raw_spin_lock(&owner->pi_lock); -/* - * Futex variants, must not use fastpath. - */ -int __sched rt_mutex_futex_trylock(struct rt_mutex *lock) -{ - return rt_mutex_slowtrylock(lock); -} + rt_mutex_dequeue_pi(owner, waiter); -int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock) -{ - return __rt_mutex_slowtrylock(lock); -} + if (rt_mutex_has_waiters(lock)) + rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock)); -/** - * __rt_mutex_futex_unlock - Futex variant, that since futex variants - * do not use the fast-path, can be simple and will not need to retry. - * - * @lock: The rt_mutex to be unlocked - * @wake_q: The wake queue head from which to get the next lock waiter - */ -bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wake_q) -{ - lockdep_assert_held(&lock->wait_lock); + rt_mutex_adjust_prio(owner); - debug_rt_mutex_unlock(lock); + /* Store the lock on which owner is blocked or NULL */ + next_lock = task_blocked_on_lock(owner); - if (!rt_mutex_has_waiters(lock)) { - lock->owner = NULL; - return false; /* done */ - } + raw_spin_unlock(&owner->pi_lock); /* - * We've already deboosted, mark_wakeup_next_waiter() will - * retain preempt_disabled when we drop the wait_lock, to - * avoid inversion prior to the wakeup. preempt_disable() - * therein pairs with rt_mutex_postunlock(). + * Don't walk the chain, if the owner task is not blocked + * itself. */ - mark_wakeup_next_waiter(wake_q, lock); + if (!next_lock) + return; - return true; /* call postunlock() */ -} + /* gets dropped in rt_mutex_adjust_prio_chain()! */ + get_task_struct(owner); -void __sched rt_mutex_futex_unlock(struct rt_mutex *lock) -{ - DEFINE_WAKE_Q(wake_q); - unsigned long flags; - bool postunlock; + raw_spin_unlock_irq(&lock->wait_lock); - raw_spin_lock_irqsave(&lock->wait_lock, flags); - postunlock = __rt_mutex_futex_unlock(lock, &wake_q); - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + rt_mutex_adjust_prio_chain(owner, RT_MUTEX_MIN_CHAINWALK, lock, + next_lock, NULL, current); - if (postunlock) - rt_mutex_postunlock(&wake_q); + raw_spin_lock_irq(&lock->wait_lock); } /** - * __rt_mutex_init - initialize the rt_mutex - * - * @lock: The rt_mutex to be initialized - * @name: The lock name used for debugging - * @key: The lock class key used for debugging - * - * Initialize the rt_mutex to unlocked state. + * rt_mutex_slowlock_block() - Perform the wait-wake-try-to-take loop + * @lock: the rt_mutex to take + * @ww_ctx: WW mutex context pointer + * @state: the state the task should block in (TASK_INTERRUPTIBLE + * or TASK_UNINTERRUPTIBLE) + * @timeout: the pre-initialized and started timer, or NULL for none + * @waiter: the pre-initialized rt_mutex_waiter * - * Initializing of a locked rt_mutex is not allowed + * Must be called with lock->wait_lock held and interrupts disabled */ -void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name, - struct lock_class_key *key) +static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state, + struct hrtimer_sleeper *timeout, + struct rt_mutex_waiter *waiter) { - debug_check_no_locks_freed((void *)lock, sizeof(*lock)); - lockdep_init_map(&lock->dep_map, name, key, 0); + struct rt_mutex *rtm = container_of(lock, struct rt_mutex, rtmutex); + struct task_struct *owner; + int ret = 0; - __rt_mutex_basic_init(lock); -} -EXPORT_SYMBOL_GPL(__rt_mutex_init); + for (;;) { + /* Try to acquire the lock: */ + if (try_to_take_rt_mutex(lock, current, waiter)) + break; -/** - * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a - * proxy owner - * - * @lock: the rt_mutex to be locked - * @proxy_owner:the task to set as owner - * - * No locking. Caller has to do serializing itself - * - * Special API call for PI-futex support. This initializes the rtmutex and - * assigns it to @proxy_owner. Concurrent operations on the rtmutex are not - * possible at this point because the pi_state which contains the rtmutex - * is not yet visible to other tasks. - */ -void __sched rt_mutex_init_proxy_locked(struct rt_mutex *lock, - struct task_struct *proxy_owner) -{ - __rt_mutex_basic_init(lock); - rt_mutex_set_owner(lock, proxy_owner); + if (timeout && !timeout->task) { + ret = -ETIMEDOUT; + break; + } + if (signal_pending_state(state, current)) { + ret = -EINTR; + break; + } + + if (build_ww_mutex() && ww_ctx) { + ret = __ww_mutex_check_kill(rtm, waiter, ww_ctx); + if (ret) + break; + } + + if (waiter == rt_mutex_top_waiter(lock)) + owner = rt_mutex_owner(lock); + else + owner = NULL; + raw_spin_unlock_irq(&lock->wait_lock); + + if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner)) + schedule(); + + raw_spin_lock_irq(&lock->wait_lock); + set_current_state(state); + } + + __set_current_state(TASK_RUNNING); + return ret; } -/** - * rt_mutex_proxy_unlock - release a lock on behalf of owner - * - * @lock: the rt_mutex to be locked - * - * No locking. Caller has to do serializing itself - * - * Special API call for PI-futex support. This merrily cleans up the rtmutex - * (debugging) state. Concurrent operations on this rt_mutex are not - * possible because it belongs to the pi_state which is about to be freed - * and it is not longer visible to other tasks. - */ -void __sched rt_mutex_proxy_unlock(struct rt_mutex *lock) +static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, + struct rt_mutex_waiter *w) { - debug_rt_mutex_proxy_unlock(lock); - rt_mutex_set_owner(lock, NULL); + /* + * If the result is not -EDEADLOCK or the caller requested + * deadlock detection, nothing to do here. + */ + if (res != -EDEADLOCK || detect_deadlock) + return; + + if (build_ww_mutex() && w->ww_ctx) + return; + + /* + * Yell loudly and stop the task right here. + */ + WARN(1, "rtmutex deadlock detected\n"); + while (1) { + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + } } /** - * __rt_mutex_start_proxy_lock() - Start lock acquisition for another task - * @lock: the rt_mutex to take - * @waiter: the pre-initialized rt_mutex_waiter - * @task: the task to prepare - * - * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock - * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. - * - * NOTE: does _NOT_ remove the @waiter on failure; must either call - * rt_mutex_wait_proxy_lock() or rt_mutex_cleanup_proxy_lock() after this. - * - * Returns: - * 0 - task blocked on lock - * 1 - acquired the lock for task, caller should wake it up - * <0 - error - * - * Special API call for PI-futex support. + * __rt_mutex_slowlock - Locking slowpath invoked with lock::wait_lock held + * @lock: The rtmutex to block lock + * @ww_ctx: WW mutex context pointer + * @state: The task state for sleeping + * @chwalk: Indicator whether full or partial chainwalk is requested + * @waiter: Initializer waiter for blocking */ -int __sched __rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task) +static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state, + enum rtmutex_chainwalk chwalk, + struct rt_mutex_waiter *waiter) { + struct rt_mutex *rtm = container_of(lock, struct rt_mutex, rtmutex); + struct ww_mutex *ww = ww_container_of(rtm); int ret; lockdep_assert_held(&lock->wait_lock); - if (try_to_take_rt_mutex(lock, task, NULL)) - return 1; + /* Try to acquire the lock again: */ + if (try_to_take_rt_mutex(lock, current, NULL)) { + if (build_ww_mutex() && ww_ctx) { + __ww_mutex_check_waiters(rtm, ww_ctx); + ww_mutex_lock_acquired(ww, ww_ctx); + } + return 0; + } - /* We enforce deadlock detection for futexes */ - ret = task_blocks_on_rt_mutex(lock, waiter, task, - RT_MUTEX_FULL_CHAINWALK); + set_current_state(state); - if (ret && !rt_mutex_owner(lock)) { - /* - * Reset the return value. We might have - * returned with -EDEADLK and the owner - * released the lock while we were walking the - * pi chain. Let the waiter sort it out. - */ - ret = 0; + ret = task_blocks_on_rt_mutex(lock, waiter, current, ww_ctx, chwalk); + if (likely(!ret)) + ret = rt_mutex_slowlock_block(lock, ww_ctx, state, NULL, waiter); + + if (likely(!ret)) { + /* acquired the lock */ + if (build_ww_mutex() && ww_ctx) { + if (!ww_ctx->is_wait_die) + __ww_mutex_check_waiters(rtm, ww_ctx); + ww_mutex_lock_acquired(ww, ww_ctx); + } + } else { + __set_current_state(TASK_RUNNING); + remove_waiter(lock, waiter); + rt_mutex_handle_deadlock(ret, chwalk, waiter); } + /* + * try_to_take_rt_mutex() sets the waiter bit + * unconditionally. We might have to fix that up. + */ + fixup_rt_mutex_waiters(lock); return ret; } -/** - * rt_mutex_start_proxy_lock() - Start lock acquisition for another task - * @lock: the rt_mutex to take - * @waiter: the pre-initialized rt_mutex_waiter - * @task: the task to prepare - * - * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock - * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. - * - * NOTE: unlike __rt_mutex_start_proxy_lock this _DOES_ remove the @waiter - * on failure. - * - * Returns: - * 0 - task blocked on lock - * 1 - acquired the lock for task, caller should wake it up - * <0 - error - * - * Special API call for PI-futex support. - */ -int __sched rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task) +static inline int __rt_mutex_slowlock_locked(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state) { + struct rt_mutex_waiter waiter; int ret; - raw_spin_lock_irq(&lock->wait_lock); - ret = __rt_mutex_start_proxy_lock(lock, waiter, task); - if (unlikely(ret)) - remove_waiter(lock, waiter); - raw_spin_unlock_irq(&lock->wait_lock); + rt_mutex_init_waiter(&waiter); + waiter.ww_ctx = ww_ctx; + ret = __rt_mutex_slowlock(lock, ww_ctx, state, RT_MUTEX_MIN_CHAINWALK, + &waiter); + + debug_rt_mutex_free_waiter(&waiter); return ret; } -/** - * rt_mutex_wait_proxy_lock() - Wait for lock acquisition - * @lock: the rt_mutex we were woken on - * @to: the timeout, null if none. hrtimer should already have - * been started. - * @waiter: the pre-initialized rt_mutex_waiter - * - * Wait for the lock acquisition started on our behalf by - * rt_mutex_start_proxy_lock(). Upon failure, the caller must call - * rt_mutex_cleanup_proxy_lock(). - * - * Returns: - * 0 - success - * <0 - error, one of -EINTR, -ETIMEDOUT - * - * Special API call for PI-futex support +/* + * rt_mutex_slowlock - Locking slowpath invoked when fast path fails + * @lock: The rtmutex to block lock + * @ww_ctx: WW mutex context pointer + * @state: The task state for sleeping */ -int __sched rt_mutex_wait_proxy_lock(struct rt_mutex *lock, - struct hrtimer_sleeper *to, - struct rt_mutex_waiter *waiter) +static int __sched rt_mutex_slowlock(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state) { + unsigned long flags; int ret; - raw_spin_lock_irq(&lock->wait_lock); - /* sleep on the mutex */ - set_current_state(TASK_INTERRUPTIBLE); - ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter); /* - * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might - * have to fix that up. + * Technically we could use raw_spin_[un]lock_irq() here, but this can + * be called in early boot if the cmpxchg() fast path is disabled + * (debug, no architecture support). In this case we will acquire the + * rtmutex with lock->wait_lock held. But we cannot unconditionally + * enable interrupts in that early boot case. So we need to use the + * irqsave/restore variants. */ - fixup_rt_mutex_waiters(lock); - raw_spin_unlock_irq(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); + ret = __rt_mutex_slowlock_locked(lock, ww_ctx, state); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); return ret; } +static __always_inline int __rt_mutex_lock(struct rt_mutex_base *lock, + unsigned int state) +{ + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) + return 0; + + return rt_mutex_slowlock(lock, NULL, state); +} +#endif /* RT_MUTEX_BUILD_MUTEX */ + +#ifdef RT_MUTEX_BUILD_SPINLOCKS +/* + * Functions required for spin/rw_lock substitution on RT kernels + */ + /** - * rt_mutex_cleanup_proxy_lock() - Cleanup failed lock acquisition - * @lock: the rt_mutex we were woken on - * @waiter: the pre-initialized rt_mutex_waiter - * - * Attempt to clean up after a failed __rt_mutex_start_proxy_lock() or - * rt_mutex_wait_proxy_lock(). - * - * Unless we acquired the lock; we're still enqueued on the wait-list and can - * in fact still be granted ownership until we're removed. Therefore we can - * find we are in fact the owner and must disregard the - * rt_mutex_wait_proxy_lock() failure. - * - * Returns: - * true - did the cleanup, we done. - * false - we acquired the lock after rt_mutex_wait_proxy_lock() returned, - * caller should disregards its return value. - * - * Special API call for PI-futex support + * rtlock_slowlock_locked - Slow path lock acquisition for RT locks + * @lock: The underlying RT mutex */ -bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter) +static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock) { - bool cleanup = false; + struct rt_mutex_waiter waiter; + struct task_struct *owner; - raw_spin_lock_irq(&lock->wait_lock); - /* - * Do an unconditional try-lock, this deals with the lock stealing - * state where __rt_mutex_futex_unlock() -> mark_wakeup_next_waiter() - * sets a NULL owner. - * - * We're not interested in the return value, because the subsequent - * test on rt_mutex_owner() will infer that. If the trylock succeeded, - * we will own the lock and it will have removed the waiter. If we - * failed the trylock, we're still not owner and we need to remove - * ourselves. - */ - try_to_take_rt_mutex(lock, current, waiter); - /* - * Unless we're the owner; we're still enqueued on the wait_list. - * So check if we became owner, if not, take us off the wait_list. - */ - if (rt_mutex_owner(lock) != current) { - remove_waiter(lock, waiter); - cleanup = true; + lockdep_assert_held(&lock->wait_lock); + + if (try_to_take_rt_mutex(lock, current, NULL)) + return; + + rt_mutex_init_rtlock_waiter(&waiter); + + /* Save current state and set state to TASK_RTLOCK_WAIT */ + current_save_and_set_rtlock_wait_state(); + + task_blocks_on_rt_mutex(lock, &waiter, current, NULL, RT_MUTEX_MIN_CHAINWALK); + + for (;;) { + /* Try to acquire the lock again */ + if (try_to_take_rt_mutex(lock, current, &waiter)) + break; + + if (&waiter == rt_mutex_top_waiter(lock)) + owner = rt_mutex_owner(lock); + else + owner = NULL; + raw_spin_unlock_irq(&lock->wait_lock); + + if (!owner || !rtmutex_spin_on_owner(lock, &waiter, owner)) + schedule_rtlock(); + + raw_spin_lock_irq(&lock->wait_lock); + set_current_state(TASK_RTLOCK_WAIT); } + + /* Restore the task state */ + current_restore_rtlock_saved_state(); + /* - * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might - * have to fix that up. + * try_to_take_rt_mutex() sets the waiter bit unconditionally. + * We might have to fix that up: */ fixup_rt_mutex_waiters(lock); - - raw_spin_unlock_irq(&lock->wait_lock); - - return cleanup; + debug_rt_mutex_free_waiter(&waiter); } -#ifdef CONFIG_DEBUG_RT_MUTEXES -void rt_mutex_debug_task_free(struct task_struct *task) +static __always_inline void __sched rtlock_slowlock(struct rt_mutex_base *lock) { - DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root)); - DEBUG_LOCKS_WARN_ON(task->pi_blocked_on); + unsigned long flags; + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + rtlock_slowlock_locked(lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); } -#endif + +#endif /* RT_MUTEX_BUILD_SPINLOCKS */ diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c new file mode 100644 index 000000000000..5c9299aaabae --- /dev/null +++ b/kernel/locking/rtmutex_api.c @@ -0,0 +1,590 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtmutex API + */ +#include <linux/spinlock.h> +#include <linux/export.h> + +#define RT_MUTEX_BUILD_MUTEX +#include "rtmutex.c" + +/* + * Max number of times we'll walk the boosting chain: + */ +int max_lock_depth = 1024; + +/* + * Debug aware fast / slowpath lock,trylock,unlock + * + * The atomic acquire/release ops are compiled away, when either the + * architecture does not support cmpxchg or when debugging is enabled. + */ +static __always_inline int __rt_mutex_lock_common(struct rt_mutex *lock, + unsigned int state, + unsigned int subclass) +{ + int ret; + + might_sleep(); + mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + ret = __rt_mutex_lock(&lock->rtmutex, state); + if (ret) + mutex_release(&lock->dep_map, _RET_IP_); + return ret; +} + +void rt_mutex_base_init(struct rt_mutex_base *rtb) +{ + __rt_mutex_base_init(rtb); +} +EXPORT_SYMBOL(rt_mutex_base_init); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +/** + * rt_mutex_lock_nested - lock a rt_mutex + * + * @lock: the rt_mutex to be locked + * @subclass: the lockdep subclass + */ +void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass) +{ + __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock_nested); + +#else /* !CONFIG_DEBUG_LOCK_ALLOC */ + +/** + * rt_mutex_lock - lock a rt_mutex + * + * @lock: the rt_mutex to be locked + */ +void __sched rt_mutex_lock(struct rt_mutex *lock) +{ + __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock); +#endif + +/** + * rt_mutex_lock_interruptible - lock a rt_mutex interruptible + * + * @lock: the rt_mutex to be locked + * + * Returns: + * 0 on success + * -EINTR when interrupted by a signal + */ +int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock) +{ + return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); + +/** + * rt_mutex_trylock - try to lock a rt_mutex + * + * @lock: the rt_mutex to be locked + * + * This function can only be called in thread context. It's safe to call it + * from atomic regions, but not from hard or soft interrupt context. + * + * Returns: + * 1 on success + * 0 on contention + */ +int __sched rt_mutex_trylock(struct rt_mutex *lock) +{ + int ret; + + if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) + return 0; + + ret = __rt_mutex_trylock(&lock->rtmutex); + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; +} +EXPORT_SYMBOL_GPL(rt_mutex_trylock); + +/** + * rt_mutex_unlock - unlock a rt_mutex + * + * @lock: the rt_mutex to be unlocked + */ +void __sched rt_mutex_unlock(struct rt_mutex *lock) +{ + mutex_release(&lock->dep_map, _RET_IP_); + __rt_mutex_unlock(&lock->rtmutex); +} +EXPORT_SYMBOL_GPL(rt_mutex_unlock); + +/* + * Futex variants, must not use fastpath. + */ +int __sched rt_mutex_futex_trylock(struct rt_mutex_base *lock) +{ + return rt_mutex_slowtrylock(lock); +} + +int __sched __rt_mutex_futex_trylock(struct rt_mutex_base *lock) +{ + return __rt_mutex_slowtrylock(lock); +} + +/** + * __rt_mutex_futex_unlock - Futex variant, that since futex variants + * do not use the fast-path, can be simple and will not need to retry. + * + * @lock: The rt_mutex to be unlocked + * @wqh: The wake queue head from which to get the next lock waiter + */ +bool __sched __rt_mutex_futex_unlock(struct rt_mutex_base *lock, + struct rt_wake_q_head *wqh) +{ + lockdep_assert_held(&lock->wait_lock); + + debug_rt_mutex_unlock(lock); + + if (!rt_mutex_has_waiters(lock)) { + lock->owner = NULL; + return false; /* done */ + } + + /* + * We've already deboosted, mark_wakeup_next_waiter() will + * retain preempt_disabled when we drop the wait_lock, to + * avoid inversion prior to the wakeup. preempt_disable() + * therein pairs with rt_mutex_postunlock(). + */ + mark_wakeup_next_waiter(wqh, lock); + + return true; /* call postunlock() */ +} + +void __sched rt_mutex_futex_unlock(struct rt_mutex_base *lock) +{ + DEFINE_RT_WAKE_Q(wqh); + unsigned long flags; + bool postunlock; + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + postunlock = __rt_mutex_futex_unlock(lock, &wqh); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + + if (postunlock) + rt_mutex_postunlock(&wqh); +} + +/** + * __rt_mutex_init - initialize the rt_mutex + * + * @lock: The rt_mutex to be initialized + * @name: The lock name used for debugging + * @key: The lock class key used for debugging + * + * Initialize the rt_mutex to unlocked state. + * + * Initializing of a locked rt_mutex is not allowed + */ +void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + __rt_mutex_base_init(&lock->rtmutex); + lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP); +} +EXPORT_SYMBOL_GPL(__rt_mutex_init); + +/** + * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a + * proxy owner + * + * @lock: the rt_mutex to be locked + * @proxy_owner:the task to set as owner + * + * No locking. Caller has to do serializing itself + * + * Special API call for PI-futex support. This initializes the rtmutex and + * assigns it to @proxy_owner. Concurrent operations on the rtmutex are not + * possible at this point because the pi_state which contains the rtmutex + * is not yet visible to other tasks. + */ +void __sched rt_mutex_init_proxy_locked(struct rt_mutex_base *lock, + struct task_struct *proxy_owner) +{ + static struct lock_class_key pi_futex_key; + + __rt_mutex_base_init(lock); + /* + * On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping' + * and rtmutex based. That causes a lockdep false positive, because + * some of the futex functions invoke spin_unlock(&hb->lock) with + * the wait_lock of the rtmutex associated to the pi_futex held. + * spin_unlock() in turn takes wait_lock of the rtmutex on which + * the spinlock is based, which makes lockdep notice a lock + * recursion. Give the futex/rtmutex wait_lock a separate key. + */ + lockdep_set_class(&lock->wait_lock, &pi_futex_key); + rt_mutex_set_owner(lock, proxy_owner); +} + +/** + * rt_mutex_proxy_unlock - release a lock on behalf of owner + * + * @lock: the rt_mutex to be locked + * + * No locking. Caller has to do serializing itself + * + * Special API call for PI-futex support. This just cleans up the rtmutex + * (debugging) state. Concurrent operations on this rt_mutex are not + * possible because it belongs to the pi_state which is about to be freed + * and it is not longer visible to other tasks. + */ +void __sched rt_mutex_proxy_unlock(struct rt_mutex_base *lock) +{ + debug_rt_mutex_proxy_unlock(lock); + rt_mutex_set_owner(lock, NULL); +} + +/** + * __rt_mutex_start_proxy_lock() - Start lock acquisition for another task + * @lock: the rt_mutex to take + * @waiter: the pre-initialized rt_mutex_waiter + * @task: the task to prepare + * + * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock + * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. + * + * NOTE: does _NOT_ remove the @waiter on failure; must either call + * rt_mutex_wait_proxy_lock() or rt_mutex_cleanup_proxy_lock() after this. + * + * Returns: + * 0 - task blocked on lock + * 1 - acquired the lock for task, caller should wake it up + * <0 - error + * + * Special API call for PI-futex support. + */ +int __sched __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task) +{ + int ret; + + lockdep_assert_held(&lock->wait_lock); + + if (try_to_take_rt_mutex(lock, task, NULL)) + return 1; + + /* We enforce deadlock detection for futexes */ + ret = task_blocks_on_rt_mutex(lock, waiter, task, NULL, + RT_MUTEX_FULL_CHAINWALK); + + if (ret && !rt_mutex_owner(lock)) { + /* + * Reset the return value. We might have + * returned with -EDEADLK and the owner + * released the lock while we were walking the + * pi chain. Let the waiter sort it out. + */ + ret = 0; + } + + return ret; +} + +/** + * rt_mutex_start_proxy_lock() - Start lock acquisition for another task + * @lock: the rt_mutex to take + * @waiter: the pre-initialized rt_mutex_waiter + * @task: the task to prepare + * + * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock + * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. + * + * NOTE: unlike __rt_mutex_start_proxy_lock this _DOES_ remove the @waiter + * on failure. + * + * Returns: + * 0 - task blocked on lock + * 1 - acquired the lock for task, caller should wake it up + * <0 - error + * + * Special API call for PI-futex support. + */ +int __sched rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task) +{ + int ret; + + raw_spin_lock_irq(&lock->wait_lock); + ret = __rt_mutex_start_proxy_lock(lock, waiter, task); + if (unlikely(ret)) + remove_waiter(lock, waiter); + raw_spin_unlock_irq(&lock->wait_lock); + + return ret; +} + +/** + * rt_mutex_wait_proxy_lock() - Wait for lock acquisition + * @lock: the rt_mutex we were woken on + * @to: the timeout, null if none. hrtimer should already have + * been started. + * @waiter: the pre-initialized rt_mutex_waiter + * + * Wait for the lock acquisition started on our behalf by + * rt_mutex_start_proxy_lock(). Upon failure, the caller must call + * rt_mutex_cleanup_proxy_lock(). + * + * Returns: + * 0 - success + * <0 - error, one of -EINTR, -ETIMEDOUT + * + * Special API call for PI-futex support + */ +int __sched rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock, + struct hrtimer_sleeper *to, + struct rt_mutex_waiter *waiter) +{ + int ret; + + raw_spin_lock_irq(&lock->wait_lock); + /* sleep on the mutex */ + set_current_state(TASK_INTERRUPTIBLE); + ret = rt_mutex_slowlock_block(lock, NULL, TASK_INTERRUPTIBLE, to, waiter); + /* + * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might + * have to fix that up. + */ + fixup_rt_mutex_waiters(lock); + raw_spin_unlock_irq(&lock->wait_lock); + + return ret; +} + +/** + * rt_mutex_cleanup_proxy_lock() - Cleanup failed lock acquisition + * @lock: the rt_mutex we were woken on + * @waiter: the pre-initialized rt_mutex_waiter + * + * Attempt to clean up after a failed __rt_mutex_start_proxy_lock() or + * rt_mutex_wait_proxy_lock(). + * + * Unless we acquired the lock; we're still enqueued on the wait-list and can + * in fact still be granted ownership until we're removed. Therefore we can + * find we are in fact the owner and must disregard the + * rt_mutex_wait_proxy_lock() failure. + * + * Returns: + * true - did the cleanup, we done. + * false - we acquired the lock after rt_mutex_wait_proxy_lock() returned, + * caller should disregards its return value. + * + * Special API call for PI-futex support + */ +bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter) +{ + bool cleanup = false; + + raw_spin_lock_irq(&lock->wait_lock); + /* + * Do an unconditional try-lock, this deals with the lock stealing + * state where __rt_mutex_futex_unlock() -> mark_wakeup_next_waiter() + * sets a NULL owner. + * + * We're not interested in the return value, because the subsequent + * test on rt_mutex_owner() will infer that. If the trylock succeeded, + * we will own the lock and it will have removed the waiter. If we + * failed the trylock, we're still not owner and we need to remove + * ourselves. + */ + try_to_take_rt_mutex(lock, current, waiter); + /* + * Unless we're the owner; we're still enqueued on the wait_list. + * So check if we became owner, if not, take us off the wait_list. + */ + if (rt_mutex_owner(lock) != current) { + remove_waiter(lock, waiter); + cleanup = true; + } + /* + * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might + * have to fix that up. + */ + fixup_rt_mutex_waiters(lock); + + raw_spin_unlock_irq(&lock->wait_lock); + + return cleanup; +} + +/* + * Recheck the pi chain, in case we got a priority setting + * + * Called from sched_setscheduler + */ +void __sched rt_mutex_adjust_pi(struct task_struct *task) +{ + struct rt_mutex_waiter *waiter; + struct rt_mutex_base *next_lock; + unsigned long flags; + + raw_spin_lock_irqsave(&task->pi_lock, flags); + + waiter = task->pi_blocked_on; + if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { + raw_spin_unlock_irqrestore(&task->pi_lock, flags); + return; + } + next_lock = waiter->lock; + raw_spin_unlock_irqrestore(&task->pi_lock, flags); + + /* gets dropped in rt_mutex_adjust_prio_chain()! */ + get_task_struct(task); + + rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL, + next_lock, NULL, task); +} + +/* + * Performs the wakeup of the top-waiter and re-enables preemption. + */ +void __sched rt_mutex_postunlock(struct rt_wake_q_head *wqh) +{ + rt_mutex_wake_up_q(wqh); +} + +#ifdef CONFIG_DEBUG_RT_MUTEXES +void rt_mutex_debug_task_free(struct task_struct *task) +{ + DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root)); + DEBUG_LOCKS_WARN_ON(task->pi_blocked_on); +} +#endif + +#ifdef CONFIG_PREEMPT_RT +/* Mutexes */ +void __mutex_rt_init(struct mutex *mutex, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)mutex, sizeof(*mutex)); + lockdep_init_map_wait(&mutex->dep_map, name, key, 0, LD_WAIT_SLEEP); +} +EXPORT_SYMBOL(__mutex_rt_init); + +static __always_inline int __mutex_lock_common(struct mutex *lock, + unsigned int state, + unsigned int subclass, + struct lockdep_map *nest_lock, + unsigned long ip) +{ + int ret; + + might_sleep(); + mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip); + ret = __rt_mutex_lock(&lock->rtmutex, state); + if (ret) + mutex_release(&lock->dep_map, ip); + else + lock_acquired(&lock->dep_map, ip); + return ret; +} + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __sched mutex_lock_nested(struct mutex *lock, unsigned int subclass) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_nested); + +void __sched _mutex_lock_nest_lock(struct mutex *lock, + struct lockdep_map *nest_lock) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, nest_lock, _RET_IP_); +} +EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock); + +int __sched mutex_lock_interruptible_nested(struct mutex *lock, + unsigned int subclass) +{ + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); + +int __sched mutex_lock_killable_nested(struct mutex *lock, + unsigned int subclass) +{ + return __mutex_lock_common(lock, TASK_KILLABLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); + +void __sched mutex_lock_io_nested(struct mutex *lock, unsigned int subclass) +{ + int token; + + might_sleep(); + + token = io_schedule_prepare(); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); + io_schedule_finish(token); +} +EXPORT_SYMBOL_GPL(mutex_lock_io_nested); + +#else /* CONFIG_DEBUG_LOCK_ALLOC */ + +void __sched mutex_lock(struct mutex *lock) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock); + +int __sched mutex_lock_interruptible(struct mutex *lock) +{ + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock_interruptible); + +int __sched mutex_lock_killable(struct mutex *lock) +{ + return __mutex_lock_common(lock, TASK_KILLABLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock_killable); + +void __sched mutex_lock_io(struct mutex *lock) +{ + int token = io_schedule_prepare(); + + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); + io_schedule_finish(token); +} +EXPORT_SYMBOL(mutex_lock_io); +#endif /* !CONFIG_DEBUG_LOCK_ALLOC */ + +int __sched mutex_trylock(struct mutex *lock) +{ + int ret; + + if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) + return 0; + + ret = __rt_mutex_trylock(&lock->rtmutex); + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; +} +EXPORT_SYMBOL(mutex_trylock); + +void __sched mutex_unlock(struct mutex *lock) +{ + mutex_release(&lock->dep_map, _RET_IP_); + __rt_mutex_unlock(&lock->rtmutex); +} +EXPORT_SYMBOL(mutex_unlock); + +#endif /* CONFIG_PREEMPT_RT */ diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index a90c22abdbca..c47e8361bfb5 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -25,29 +25,90 @@ * @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree * @task: task reference to the blocked task * @lock: Pointer to the rt_mutex on which the waiter blocks + * @wake_state: Wakeup state to use (TASK_NORMAL or TASK_RTLOCK_WAIT) * @prio: Priority of the waiter * @deadline: Deadline of the waiter if applicable + * @ww_ctx: WW context pointer */ struct rt_mutex_waiter { struct rb_node tree_entry; struct rb_node pi_tree_entry; struct task_struct *task; - struct rt_mutex *lock; + struct rt_mutex_base *lock; + unsigned int wake_state; int prio; u64 deadline; + struct ww_acquire_ctx *ww_ctx; }; +/** + * rt_wake_q_head - Wrapper around regular wake_q_head to support + * "sleeping" spinlocks on RT + * @head: The regular wake_q_head for sleeping lock variants + * @rtlock_task: Task pointer for RT lock (spin/rwlock) wakeups + */ +struct rt_wake_q_head { + struct wake_q_head head; + struct task_struct *rtlock_task; +}; + +#define DEFINE_RT_WAKE_Q(name) \ + struct rt_wake_q_head name = { \ + .head = WAKE_Q_HEAD_INITIALIZER(name.head), \ + .rtlock_task = NULL, \ + } + +/* + * PI-futex support (proxy locking functions, etc.): + */ +extern void rt_mutex_init_proxy_locked(struct rt_mutex_base *lock, + struct task_struct *proxy_owner); +extern void rt_mutex_proxy_unlock(struct rt_mutex_base *lock); +extern int __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task); +extern int rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task); +extern int rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock, + struct hrtimer_sleeper *to, + struct rt_mutex_waiter *waiter); +extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter); + +extern int rt_mutex_futex_trylock(struct rt_mutex_base *l); +extern int __rt_mutex_futex_trylock(struct rt_mutex_base *l); + +extern void rt_mutex_futex_unlock(struct rt_mutex_base *lock); +extern bool __rt_mutex_futex_unlock(struct rt_mutex_base *lock, + struct rt_wake_q_head *wqh); + +extern void rt_mutex_postunlock(struct rt_wake_q_head *wqh); + /* * Must be guarded because this header is included from rcu/tree_plugin.h * unconditionally. */ #ifdef CONFIG_RT_MUTEXES -static inline int rt_mutex_has_waiters(struct rt_mutex *lock) +static inline int rt_mutex_has_waiters(struct rt_mutex_base *lock) { return !RB_EMPTY_ROOT(&lock->waiters.rb_root); } -static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex *lock) +/* + * Lockless speculative check whether @waiter is still the top waiter on + * @lock. This is solely comparing pointers and not derefencing the + * leftmost entry which might be about to vanish. + */ +static inline bool rt_mutex_waiter_is_top_waiter(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter) +{ + struct rb_node *leftmost = rb_first_cached(&lock->waiters); + + return rb_entry(leftmost, struct rt_mutex_waiter, tree_entry) == waiter; +} + +static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex_base *lock) { struct rb_node *leftmost = rb_first_cached(&lock->waiters); struct rt_mutex_waiter *w = NULL; @@ -72,19 +133,12 @@ static inline struct rt_mutex_waiter *task_top_pi_waiter(struct task_struct *p) #define RT_MUTEX_HAS_WAITERS 1UL -static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) +static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock) { unsigned long owner = (unsigned long) READ_ONCE(lock->owner); return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS); } -#else /* CONFIG_RT_MUTEXES */ -/* Used in rcu/tree_plugin.h */ -static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) -{ - return NULL; -} -#endif /* !CONFIG_RT_MUTEXES */ /* * Constants for rt mutex functions which have a selectable deadlock @@ -101,49 +155,21 @@ enum rtmutex_chainwalk { RT_MUTEX_FULL_CHAINWALK, }; -static inline void __rt_mutex_basic_init(struct rt_mutex *lock) +static inline void __rt_mutex_base_init(struct rt_mutex_base *lock) { - lock->owner = NULL; raw_spin_lock_init(&lock->wait_lock); lock->waiters = RB_ROOT_CACHED; + lock->owner = NULL; } -/* - * PI-futex support (proxy locking functions, etc.): - */ -extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, - struct task_struct *proxy_owner); -extern void rt_mutex_proxy_unlock(struct rt_mutex *lock); -extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter); -extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task); -extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task); -extern int rt_mutex_wait_proxy_lock(struct rt_mutex *lock, - struct hrtimer_sleeper *to, - struct rt_mutex_waiter *waiter); -extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter); - -extern int rt_mutex_futex_trylock(struct rt_mutex *l); -extern int __rt_mutex_futex_trylock(struct rt_mutex *l); - -extern void rt_mutex_futex_unlock(struct rt_mutex *lock); -extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wqh); - -extern void rt_mutex_postunlock(struct wake_q_head *wake_q); - /* Debug functions */ -static inline void debug_rt_mutex_unlock(struct rt_mutex *lock) +static inline void debug_rt_mutex_unlock(struct rt_mutex_base *lock) { if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES)) DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current); } -static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock) +static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex_base *lock) { if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES)) DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock)); @@ -161,4 +187,27 @@ static inline void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter) memset(waiter, 0x22, sizeof(*waiter)); } +static inline void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) +{ + debug_rt_mutex_init_waiter(waiter); + RB_CLEAR_NODE(&waiter->pi_tree_entry); + RB_CLEAR_NODE(&waiter->tree_entry); + waiter->wake_state = TASK_NORMAL; + waiter->task = NULL; +} + +static inline void rt_mutex_init_rtlock_waiter(struct rt_mutex_waiter *waiter) +{ + rt_mutex_init_waiter(waiter); + waiter->wake_state = TASK_RTLOCK_WAIT; +} + +#else /* CONFIG_RT_MUTEXES */ +/* Used in rcu/tree_plugin.h */ +static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock) +{ + return NULL; +} +#endif /* !CONFIG_RT_MUTEXES */ + #endif diff --git a/kernel/locking/rwbase_rt.c b/kernel/locking/rwbase_rt.c new file mode 100644 index 000000000000..88191f6e252c --- /dev/null +++ b/kernel/locking/rwbase_rt.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0-only + +/* + * RT-specific reader/writer semaphores and reader/writer locks + * + * down_write/write_lock() + * 1) Lock rtmutex + * 2) Remove the reader BIAS to force readers into the slow path + * 3) Wait until all readers have left the critical section + * 4) Mark it write locked + * + * up_write/write_unlock() + * 1) Remove the write locked marker + * 2) Set the reader BIAS, so readers can use the fast path again + * 3) Unlock rtmutex, to release blocked readers + * + * down_read/read_lock() + * 1) Try fast path acquisition (reader BIAS is set) + * 2) Take tmutex::wait_lock, which protects the writelocked flag + * 3) If !writelocked, acquire it for read + * 4) If writelocked, block on tmutex + * 5) unlock rtmutex, goto 1) + * + * up_read/read_unlock() + * 1) Try fast path release (reader count != 1) + * 2) Wake the writer waiting in down_write()/write_lock() #3 + * + * down_read/read_lock()#3 has the consequence, that rw semaphores and rw + * locks on RT are not writer fair, but writers, which should be avoided in + * RT tasks (think mmap_sem), are subject to the rtmutex priority/DL + * inheritance mechanism. + * + * It's possible to make the rw primitives writer fair by keeping a list of + * active readers. A blocked writer would force all newly incoming readers + * to block on the rtmutex, but the rtmutex would have to be proxy locked + * for one reader after the other. We can't use multi-reader inheritance + * because there is no way to support that with SCHED_DEADLINE. + * Implementing the one by one reader boosting/handover mechanism is a + * major surgery for a very dubious value. + * + * The risk of writer starvation is there, but the pathological use cases + * which trigger it are not necessarily the typical RT workloads. + * + * Fast-path orderings: + * The lock/unlock of readers can run in fast paths: lock and unlock are only + * atomic ops, and there is no inner lock to provide ACQUIRE and RELEASE + * semantics of rwbase_rt. Atomic ops should thus provide _acquire() + * and _release() (or stronger). + * + * Common code shared between RT rw_semaphore and rwlock + */ + +static __always_inline int rwbase_read_trylock(struct rwbase_rt *rwb) +{ + int r; + + /* + * Increment reader count, if sem->readers < 0, i.e. READER_BIAS is + * set. + */ + for (r = atomic_read(&rwb->readers); r < 0;) { + /* Fully-ordered if cmpxchg() succeeds, provides ACQUIRE */ + if (likely(atomic_try_cmpxchg(&rwb->readers, &r, r + 1))) + return 1; + } + return 0; +} + +static int __sched __rwbase_read_lock(struct rwbase_rt *rwb, + unsigned int state) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + int ret; + + raw_spin_lock_irq(&rtm->wait_lock); + /* + * Allow readers, as long as the writer has not completely + * acquired the semaphore for write. + */ + if (atomic_read(&rwb->readers) != WRITER_BIAS) { + atomic_inc(&rwb->readers); + raw_spin_unlock_irq(&rtm->wait_lock); + return 0; + } + + /* + * Call into the slow lock path with the rtmutex->wait_lock + * held, so this can't result in the following race: + * + * Reader1 Reader2 Writer + * down_read() + * down_write() + * rtmutex_lock(m) + * wait() + * down_read() + * unlock(m->wait_lock) + * up_read() + * wake(Writer) + * lock(m->wait_lock) + * sem->writelocked=true + * unlock(m->wait_lock) + * + * up_write() + * sem->writelocked=false + * rtmutex_unlock(m) + * down_read() + * down_write() + * rtmutex_lock(m) + * wait() + * rtmutex_lock(m) + * + * That would put Reader1 behind the writer waiting on + * Reader2 to call up_read(), which might be unbound. + */ + + /* + * For rwlocks this returns 0 unconditionally, so the below + * !ret conditionals are optimized out. + */ + ret = rwbase_rtmutex_slowlock_locked(rtm, state); + + /* + * On success the rtmutex is held, so there can't be a writer + * active. Increment the reader count and immediately drop the + * rtmutex again. + * + * rtmutex->wait_lock has to be unlocked in any case of course. + */ + if (!ret) + atomic_inc(&rwb->readers); + raw_spin_unlock_irq(&rtm->wait_lock); + if (!ret) + rwbase_rtmutex_unlock(rtm); + return ret; +} + +static __always_inline int rwbase_read_lock(struct rwbase_rt *rwb, + unsigned int state) +{ + if (rwbase_read_trylock(rwb)) + return 0; + + return __rwbase_read_lock(rwb, state); +} + +static void __sched __rwbase_read_unlock(struct rwbase_rt *rwb, + unsigned int state) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + struct task_struct *owner; + + raw_spin_lock_irq(&rtm->wait_lock); + /* + * Wake the writer, i.e. the rtmutex owner. It might release the + * rtmutex concurrently in the fast path (due to a signal), but to + * clean up rwb->readers it needs to acquire rtm->wait_lock. The + * worst case which can happen is a spurious wakeup. + */ + owner = rt_mutex_owner(rtm); + if (owner) + wake_up_state(owner, state); + + raw_spin_unlock_irq(&rtm->wait_lock); +} + +static __always_inline void rwbase_read_unlock(struct rwbase_rt *rwb, + unsigned int state) +{ + /* + * rwb->readers can only hit 0 when a writer is waiting for the + * active readers to leave the critical section. + * + * dec_and_test() is fully ordered, provides RELEASE. + */ + if (unlikely(atomic_dec_and_test(&rwb->readers))) + __rwbase_read_unlock(rwb, state); +} + +static inline void __rwbase_write_unlock(struct rwbase_rt *rwb, int bias, + unsigned long flags) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + + /* + * _release() is needed in case that reader is in fast path, pairing + * with atomic_try_cmpxchg() in rwbase_read_trylock(), provides RELEASE + */ + (void)atomic_add_return_release(READER_BIAS - bias, &rwb->readers); + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + rwbase_rtmutex_unlock(rtm); +} + +static inline void rwbase_write_unlock(struct rwbase_rt *rwb) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + __rwbase_write_unlock(rwb, WRITER_BIAS, flags); +} + +static inline void rwbase_write_downgrade(struct rwbase_rt *rwb) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + /* Release it and account current as reader */ + __rwbase_write_unlock(rwb, WRITER_BIAS - 1, flags); +} + +static inline bool __rwbase_write_trylock(struct rwbase_rt *rwb) +{ + /* Can do without CAS because we're serialized by wait_lock. */ + lockdep_assert_held(&rwb->rtmutex.wait_lock); + + /* + * _acquire is needed in case the reader is in the fast path, pairing + * with rwbase_read_unlock(), provides ACQUIRE. + */ + if (!atomic_read_acquire(&rwb->readers)) { + atomic_set(&rwb->readers, WRITER_BIAS); + return 1; + } + + return 0; +} + +static int __sched rwbase_write_lock(struct rwbase_rt *rwb, + unsigned int state) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + /* Take the rtmutex as a first step */ + if (rwbase_rtmutex_lock_state(rtm, state)) + return -EINTR; + + /* Force readers into slow path */ + atomic_sub(READER_BIAS, &rwb->readers); + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + if (__rwbase_write_trylock(rwb)) + goto out_unlock; + + rwbase_set_and_save_current_state(state); + for (;;) { + /* Optimized out for rwlocks */ + if (rwbase_signal_pending_state(state, current)) { + rwbase_restore_current_state(); + __rwbase_write_unlock(rwb, 0, flags); + return -EINTR; + } + + if (__rwbase_write_trylock(rwb)) + break; + + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + rwbase_schedule(); + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + + set_current_state(state); + } + rwbase_restore_current_state(); + +out_unlock: + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + return 0; +} + +static inline int rwbase_write_trylock(struct rwbase_rt *rwb) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + if (!rwbase_rtmutex_trylock(rtm)) + return 0; + + atomic_sub(READER_BIAS, &rwb->readers); + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + if (__rwbase_write_trylock(rwb)) { + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + return 1; + } + __rwbase_write_unlock(rwb, 0, flags); + return 0; +} diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 16bfbb10c74d..000e8d5a2884 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -28,6 +28,7 @@ #include <linux/rwsem.h> #include <linux/atomic.h> +#ifndef CONFIG_PREEMPT_RT #include "lock_events.h" /* @@ -1165,7 +1166,7 @@ out_nolock: * handle waking up a waiter on the semaphore * - up_read/up_write has decremented the active part of count if we come here */ -static struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem, long count) +static struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem) { unsigned long flags; DEFINE_WAKE_Q(wake_q); @@ -1297,7 +1298,7 @@ static inline void __up_read(struct rw_semaphore *sem) if (unlikely((tmp & (RWSEM_LOCK_MASK|RWSEM_FLAG_WAITERS)) == RWSEM_FLAG_WAITERS)) { clear_nonspinnable(sem); - rwsem_wake(sem, tmp); + rwsem_wake(sem); } } @@ -1319,7 +1320,7 @@ static inline void __up_write(struct rw_semaphore *sem) rwsem_clear_owner(sem); tmp = atomic_long_fetch_add_release(-RWSEM_WRITER_LOCKED, &sem->count); if (unlikely(tmp & RWSEM_FLAG_WAITERS)) - rwsem_wake(sem, tmp); + rwsem_wake(sem); } /* @@ -1344,6 +1345,116 @@ static inline void __downgrade_write(struct rw_semaphore *sem) rwsem_downgrade_wake(sem); } +#else /* !CONFIG_PREEMPT_RT */ + +#define RT_MUTEX_BUILD_MUTEX +#include "rtmutex.c" + +#define rwbase_set_and_save_current_state(state) \ + set_current_state(state) + +#define rwbase_restore_current_state() \ + __set_current_state(TASK_RUNNING) + +#define rwbase_rtmutex_lock_state(rtm, state) \ + __rt_mutex_lock(rtm, state) + +#define rwbase_rtmutex_slowlock_locked(rtm, state) \ + __rt_mutex_slowlock_locked(rtm, NULL, state) + +#define rwbase_rtmutex_unlock(rtm) \ + __rt_mutex_unlock(rtm) + +#define rwbase_rtmutex_trylock(rtm) \ + __rt_mutex_trylock(rtm) + +#define rwbase_signal_pending_state(state, current) \ + signal_pending_state(state, current) + +#define rwbase_schedule() \ + schedule() + +#include "rwbase_rt.c" + +void __init_rwsem(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key) +{ + init_rwbase_rt(&(sem)->rwbase); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map_wait(&sem->dep_map, name, key, 0, LD_WAIT_SLEEP); +#endif +} +EXPORT_SYMBOL(__init_rwsem); + +static inline void __down_read(struct rw_semaphore *sem) +{ + rwbase_read_lock(&sem->rwbase, TASK_UNINTERRUPTIBLE); +} + +static inline int __down_read_interruptible(struct rw_semaphore *sem) +{ + return rwbase_read_lock(&sem->rwbase, TASK_INTERRUPTIBLE); +} + +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + return rwbase_read_lock(&sem->rwbase, TASK_KILLABLE); +} + +static inline int __down_read_trylock(struct rw_semaphore *sem) +{ + return rwbase_read_trylock(&sem->rwbase); +} + +static inline void __up_read(struct rw_semaphore *sem) +{ + rwbase_read_unlock(&sem->rwbase, TASK_NORMAL); +} + +static inline void __sched __down_write(struct rw_semaphore *sem) +{ + rwbase_write_lock(&sem->rwbase, TASK_UNINTERRUPTIBLE); +} + +static inline int __sched __down_write_killable(struct rw_semaphore *sem) +{ + return rwbase_write_lock(&sem->rwbase, TASK_KILLABLE); +} + +static inline int __down_write_trylock(struct rw_semaphore *sem) +{ + return rwbase_write_trylock(&sem->rwbase); +} + +static inline void __up_write(struct rw_semaphore *sem) +{ + rwbase_write_unlock(&sem->rwbase); +} + +static inline void __downgrade_write(struct rw_semaphore *sem) +{ + rwbase_write_downgrade(&sem->rwbase); +} + +/* Debug stubs for the common API */ +#define DEBUG_RWSEMS_WARN_ON(c, sem) + +static inline void __rwsem_set_reader_owned(struct rw_semaphore *sem, + struct task_struct *owner) +{ +} + +static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem) +{ + int count = atomic_read(&sem->rwbase.readers); + + return count < 0 && count != READER_BIAS; +} + +#endif /* CONFIG_PREEMPT_RT */ + /* * lock for reading */ diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c index 9aa855a96c4a..9ee381e4d2a4 100644 --- a/kernel/locking/semaphore.c +++ b/kernel/locking/semaphore.c @@ -54,6 +54,7 @@ void down(struct semaphore *sem) { unsigned long flags; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -77,6 +78,7 @@ int down_interruptible(struct semaphore *sem) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -103,6 +105,7 @@ int down_killable(struct semaphore *sem) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -157,6 +160,7 @@ int down_timeout(struct semaphore *sem, long timeout) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index c8d7ad9fb9b2..c5830cfa379a 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -124,8 +124,11 @@ void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \ * __[spin|read|write]_lock_bh() */ BUILD_LOCK_OPS(spin, raw_spinlock); + +#ifndef CONFIG_PREEMPT_RT BUILD_LOCK_OPS(read, rwlock); BUILD_LOCK_OPS(write, rwlock); +#endif #endif @@ -209,6 +212,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock) EXPORT_SYMBOL(_raw_spin_unlock_bh); #endif +#ifndef CONFIG_PREEMPT_RT + #ifndef CONFIG_INLINE_READ_TRYLOCK int __lockfunc _raw_read_trylock(rwlock_t *lock) { @@ -353,6 +358,8 @@ void __lockfunc _raw_write_unlock_bh(rwlock_t *lock) EXPORT_SYMBOL(_raw_write_unlock_bh); #endif +#endif /* !CONFIG_PREEMPT_RT */ + #ifdef CONFIG_DEBUG_LOCK_ALLOC void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass) diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index b9d93087ee66..14235671a1a7 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, EXPORT_SYMBOL(__raw_spin_lock_init); +#ifndef CONFIG_PREEMPT_RT void __rwlock_init(rwlock_t *lock, const char *name, struct lock_class_key *key) { @@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name, } EXPORT_SYMBOL(__rwlock_init); +#endif static void spin_dump(raw_spinlock_t *lock, const char *msg) { @@ -139,6 +141,7 @@ void do_raw_spin_unlock(raw_spinlock_t *lock) arch_spin_unlock(&lock->raw_lock); } +#ifndef CONFIG_PREEMPT_RT static void rwlock_bug(rwlock_t *lock, const char *msg) { if (!debug_locks_off()) @@ -228,3 +231,5 @@ void do_raw_write_unlock(rwlock_t *lock) debug_write_unlock(lock); arch_write_unlock(&lock->raw_lock); } + +#endif /* !CONFIG_PREEMPT_RT */ diff --git a/kernel/locking/spinlock_rt.c b/kernel/locking/spinlock_rt.c new file mode 100644 index 000000000000..d2912e44d61f --- /dev/null +++ b/kernel/locking/spinlock_rt.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PREEMPT_RT substitution for spin/rw_locks + * + * spinlocks and rwlocks on RT are based on rtmutexes, with a few twists to + * resemble the non RT semantics: + * + * - Contrary to plain rtmutexes, spinlocks and rwlocks are state + * preserving. The task state is saved before blocking on the underlying + * rtmutex, and restored when the lock has been acquired. Regular wakeups + * during that time are redirected to the saved state so no wake up is + * missed. + * + * - Non RT spin/rwlocks disable preemption and eventually interrupts. + * Disabling preemption has the side effect of disabling migration and + * preventing RCU grace periods. + * + * The RT substitutions explicitly disable migration and take + * rcu_read_lock() across the lock held section. + */ +#include <linux/spinlock.h> +#include <linux/export.h> + +#define RT_MUTEX_BUILD_SPINLOCKS +#include "rtmutex.c" + +static __always_inline void rtlock_lock(struct rt_mutex_base *rtm) +{ + if (unlikely(!rt_mutex_cmpxchg_acquire(rtm, NULL, current))) + rtlock_slowlock(rtm); +} + +static __always_inline void __rt_spin_lock(spinlock_t *lock) +{ + ___might_sleep(__FILE__, __LINE__, 0); + rtlock_lock(&lock->lock); + rcu_read_lock(); + migrate_disable(); +} + +void __sched rt_spin_lock(spinlock_t *lock) +{ + spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); + __rt_spin_lock(lock); +} +EXPORT_SYMBOL(rt_spin_lock); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __sched rt_spin_lock_nested(spinlock_t *lock, int subclass) +{ + spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + __rt_spin_lock(lock); +} +EXPORT_SYMBOL(rt_spin_lock_nested); + +void __sched rt_spin_lock_nest_lock(spinlock_t *lock, + struct lockdep_map *nest_lock) +{ + spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_); + __rt_spin_lock(lock); +} +EXPORT_SYMBOL(rt_spin_lock_nest_lock); +#endif + +void __sched rt_spin_unlock(spinlock_t *lock) +{ + spin_release(&lock->dep_map, _RET_IP_); + migrate_enable(); + rcu_read_unlock(); + + if (unlikely(!rt_mutex_cmpxchg_release(&lock->lock, current, NULL))) + rt_mutex_slowunlock(&lock->lock); +} +EXPORT_SYMBOL(rt_spin_unlock); + +/* + * Wait for the lock to get unlocked: instead of polling for an unlock + * (like raw spinlocks do), lock and unlock, to force the kernel to + * schedule if there's contention: + */ +void __sched rt_spin_lock_unlock(spinlock_t *lock) +{ + spin_lock(lock); + spin_unlock(lock); +} +EXPORT_SYMBOL(rt_spin_lock_unlock); + +static __always_inline int __rt_spin_trylock(spinlock_t *lock) +{ + int ret = 1; + + if (unlikely(!rt_mutex_cmpxchg_acquire(&lock->lock, NULL, current))) + ret = rt_mutex_slowtrylock(&lock->lock); + + if (ret) { + spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); + rcu_read_lock(); + migrate_disable(); + } + return ret; +} + +int __sched rt_spin_trylock(spinlock_t *lock) +{ + return __rt_spin_trylock(lock); +} +EXPORT_SYMBOL(rt_spin_trylock); + +int __sched rt_spin_trylock_bh(spinlock_t *lock) +{ + int ret; + + local_bh_disable(); + ret = __rt_spin_trylock(lock); + if (!ret) + local_bh_enable(); + return ret; +} +EXPORT_SYMBOL(rt_spin_trylock_bh); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __rt_spin_lock_init(spinlock_t *lock, const char *name, + struct lock_class_key *key, bool percpu) +{ + u8 type = percpu ? LD_LOCK_PERCPU : LD_LOCK_NORMAL; + + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map_type(&lock->dep_map, name, key, 0, LD_WAIT_CONFIG, + LD_WAIT_INV, type); +} +EXPORT_SYMBOL(__rt_spin_lock_init); +#endif + +/* + * RT-specific reader/writer locks + */ +#define rwbase_set_and_save_current_state(state) \ + current_save_and_set_rtlock_wait_state() + +#define rwbase_restore_current_state() \ + current_restore_rtlock_saved_state() + +static __always_inline int +rwbase_rtmutex_lock_state(struct rt_mutex_base *rtm, unsigned int state) +{ + if (unlikely(!rt_mutex_cmpxchg_acquire(rtm, NULL, current))) + rtlock_slowlock(rtm); + return 0; +} + +static __always_inline int +rwbase_rtmutex_slowlock_locked(struct rt_mutex_base *rtm, unsigned int state) +{ + rtlock_slowlock_locked(rtm); + return 0; +} + +static __always_inline void rwbase_rtmutex_unlock(struct rt_mutex_base *rtm) +{ + if (likely(rt_mutex_cmpxchg_acquire(rtm, current, NULL))) + return; + + rt_mutex_slowunlock(rtm); +} + +static __always_inline int rwbase_rtmutex_trylock(struct rt_mutex_base *rtm) +{ + if (likely(rt_mutex_cmpxchg_acquire(rtm, NULL, current))) + return 1; + + return rt_mutex_slowtrylock(rtm); +} + +#define rwbase_signal_pending_state(state, current) (0) + +#define rwbase_schedule() \ + schedule_rtlock() + +#include "rwbase_rt.c" +/* + * The common functions which get wrapped into the rwlock API. + */ +int __sched rt_read_trylock(rwlock_t *rwlock) +{ + int ret; + + ret = rwbase_read_trylock(&rwlock->rwbase); + if (ret) { + rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_); + rcu_read_lock(); + migrate_disable(); + } + return ret; +} +EXPORT_SYMBOL(rt_read_trylock); + +int __sched rt_write_trylock(rwlock_t *rwlock) +{ + int ret; + + ret = rwbase_write_trylock(&rwlock->rwbase); + if (ret) { + rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_); + rcu_read_lock(); + migrate_disable(); + } + return ret; +} +EXPORT_SYMBOL(rt_write_trylock); + +void __sched rt_read_lock(rwlock_t *rwlock) +{ + ___might_sleep(__FILE__, __LINE__, 0); + rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_); + rwbase_read_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT); + rcu_read_lock(); + migrate_disable(); +} +EXPORT_SYMBOL(rt_read_lock); + +void __sched rt_write_lock(rwlock_t *rwlock) +{ + ___might_sleep(__FILE__, __LINE__, 0); + rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_); + rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT); + rcu_read_lock(); + migrate_disable(); +} +EXPORT_SYMBOL(rt_write_lock); + +void __sched rt_read_unlock(rwlock_t *rwlock) +{ + rwlock_release(&rwlock->dep_map, _RET_IP_); + migrate_enable(); + rcu_read_unlock(); + rwbase_read_unlock(&rwlock->rwbase, TASK_RTLOCK_WAIT); +} +EXPORT_SYMBOL(rt_read_unlock); + +void __sched rt_write_unlock(rwlock_t *rwlock) +{ + rwlock_release(&rwlock->dep_map, _RET_IP_); + rcu_read_unlock(); + migrate_enable(); + rwbase_write_unlock(&rwlock->rwbase); +} +EXPORT_SYMBOL(rt_write_unlock); + +int __sched rt_rwlock_is_contended(rwlock_t *rwlock) +{ + return rw_base_is_contended(&rwlock->rwbase); +} +EXPORT_SYMBOL(rt_rwlock_is_contended); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __rt_rwlock_init(rwlock_t *rwlock, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)rwlock, sizeof(*rwlock)); + lockdep_init_map_wait(&rwlock->dep_map, name, key, 0, LD_WAIT_CONFIG); +} +EXPORT_SYMBOL(__rt_rwlock_init); +#endif diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h new file mode 100644 index 000000000000..56f139201f24 --- /dev/null +++ b/kernel/locking/ww_mutex.h @@ -0,0 +1,569 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef WW_RT + +#define MUTEX mutex +#define MUTEX_WAITER mutex_waiter + +static inline struct mutex_waiter * +__ww_waiter_first(struct mutex *lock) +{ + struct mutex_waiter *w; + + w = list_first_entry(&lock->wait_list, struct mutex_waiter, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline struct mutex_waiter * +__ww_waiter_next(struct mutex *lock, struct mutex_waiter *w) +{ + w = list_next_entry(w, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline struct mutex_waiter * +__ww_waiter_prev(struct mutex *lock, struct mutex_waiter *w) +{ + w = list_prev_entry(w, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline struct mutex_waiter * +__ww_waiter_last(struct mutex *lock) +{ + struct mutex_waiter *w; + + w = list_last_entry(&lock->wait_list, struct mutex_waiter, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline void +__ww_waiter_add(struct mutex *lock, struct mutex_waiter *waiter, struct mutex_waiter *pos) +{ + struct list_head *p = &lock->wait_list; + if (pos) + p = &pos->list; + __mutex_add_waiter(lock, waiter, p); +} + +static inline struct task_struct * +__ww_mutex_owner(struct mutex *lock) +{ + return __mutex_owner(lock); +} + +static inline bool +__ww_mutex_has_waiters(struct mutex *lock) +{ + return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS; +} + +static inline void lock_wait_lock(struct mutex *lock) +{ + raw_spin_lock(&lock->wait_lock); +} + +static inline void unlock_wait_lock(struct mutex *lock) +{ + raw_spin_unlock(&lock->wait_lock); +} + +static inline void lockdep_assert_wait_lock_held(struct mutex *lock) +{ + lockdep_assert_held(&lock->wait_lock); +} + +#else /* WW_RT */ + +#define MUTEX rt_mutex +#define MUTEX_WAITER rt_mutex_waiter + +static inline struct rt_mutex_waiter * +__ww_waiter_first(struct rt_mutex *lock) +{ + struct rb_node *n = rb_first(&lock->rtmutex.waiters.rb_root); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline struct rt_mutex_waiter * +__ww_waiter_next(struct rt_mutex *lock, struct rt_mutex_waiter *w) +{ + struct rb_node *n = rb_next(&w->tree_entry); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline struct rt_mutex_waiter * +__ww_waiter_prev(struct rt_mutex *lock, struct rt_mutex_waiter *w) +{ + struct rb_node *n = rb_prev(&w->tree_entry); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline struct rt_mutex_waiter * +__ww_waiter_last(struct rt_mutex *lock) +{ + struct rb_node *n = rb_last(&lock->rtmutex.waiters.rb_root); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline void +__ww_waiter_add(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, struct rt_mutex_waiter *pos) +{ + /* RT unconditionally adds the waiter first and then removes it on error */ +} + +static inline struct task_struct * +__ww_mutex_owner(struct rt_mutex *lock) +{ + return rt_mutex_owner(&lock->rtmutex); +} + +static inline bool +__ww_mutex_has_waiters(struct rt_mutex *lock) +{ + return rt_mutex_has_waiters(&lock->rtmutex); +} + +static inline void lock_wait_lock(struct rt_mutex *lock) +{ + raw_spin_lock(&lock->rtmutex.wait_lock); +} + +static inline void unlock_wait_lock(struct rt_mutex *lock) +{ + raw_spin_unlock(&lock->rtmutex.wait_lock); +} + +static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock) +{ + lockdep_assert_held(&lock->rtmutex.wait_lock); +} + +#endif /* WW_RT */ + +/* + * Wait-Die: + * The newer transactions are killed when: + * It (the new transaction) makes a request for a lock being held + * by an older transaction. + * + * Wound-Wait: + * The newer transactions are wounded when: + * An older transaction makes a request for a lock being held by + * the newer transaction. + */ + +/* + * Associate the ww_mutex @ww with the context @ww_ctx under which we acquired + * it. + */ +static __always_inline void +ww_mutex_lock_acquired(struct ww_mutex *ww, struct ww_acquire_ctx *ww_ctx) +{ +#ifdef DEBUG_WW_MUTEXES + /* + * If this WARN_ON triggers, you used ww_mutex_lock to acquire, + * but released with a normal mutex_unlock in this call. + * + * This should never happen, always use ww_mutex_unlock. + */ + DEBUG_LOCKS_WARN_ON(ww->ctx); + + /* + * Not quite done after calling ww_acquire_done() ? + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire); + + if (ww_ctx->contending_lock) { + /* + * After -EDEADLK you tried to + * acquire a different ww_mutex? Bad! + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww); + + /* + * You called ww_mutex_lock after receiving -EDEADLK, + * but 'forgot' to unlock everything else first? + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0); + ww_ctx->contending_lock = NULL; + } + + /* + * Naughty, using a different class will lead to undefined behavior! + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class); +#endif + ww_ctx->acquired++; + ww->ctx = ww_ctx; +} + +/* + * Determine if @a is 'less' than @b. IOW, either @a is a lower priority task + * or, when of equal priority, a younger transaction than @b. + * + * Depending on the algorithm, @a will either need to wait for @b, or die. + */ +static inline bool +__ww_ctx_less(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b) +{ +/* + * Can only do the RT prio for WW_RT, because task->prio isn't stable due to PI, + * so the wait_list ordering will go wobbly. rt_mutex re-queues the waiter and + * isn't affected by this. + */ +#ifdef WW_RT + /* kernel prio; less is more */ + int a_prio = a->task->prio; + int b_prio = b->task->prio; + + if (rt_prio(a_prio) || rt_prio(b_prio)) { + + if (a_prio > b_prio) + return true; + + if (a_prio < b_prio) + return false; + + /* equal static prio */ + + if (dl_prio(a_prio)) { + if (dl_time_before(b->task->dl.deadline, + a->task->dl.deadline)) + return true; + + if (dl_time_before(a->task->dl.deadline, + b->task->dl.deadline)) + return false; + } + + /* equal prio */ + } +#endif + + /* FIFO order tie break -- bigger is younger */ + return (signed long)(a->stamp - b->stamp) > 0; +} + +/* + * Wait-Die; wake a lesser waiter context (when locks held) such that it can + * die. + * + * Among waiters with context, only the first one can have other locks acquired + * already (ctx->acquired > 0), because __ww_mutex_add_waiter() and + * __ww_mutex_check_kill() wake any but the earliest context. + */ +static bool +__ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter, + struct ww_acquire_ctx *ww_ctx) +{ + if (!ww_ctx->is_wait_die) + return false; + + if (waiter->ww_ctx->acquired > 0 && __ww_ctx_less(waiter->ww_ctx, ww_ctx)) { +#ifndef WW_RT + debug_mutex_wake_waiter(lock, waiter); +#endif + wake_up_process(waiter->task); + } + + return true; +} + +/* + * Wound-Wait; wound a lesser @hold_ctx if it holds the lock. + * + * Wound the lock holder if there are waiters with more important transactions + * than the lock holders. Even if multiple waiters may wound the lock holder, + * it's sufficient that only one does. + */ +static bool __ww_mutex_wound(struct MUTEX *lock, + struct ww_acquire_ctx *ww_ctx, + struct ww_acquire_ctx *hold_ctx) +{ + struct task_struct *owner = __ww_mutex_owner(lock); + + lockdep_assert_wait_lock_held(lock); + + /* + * Possible through __ww_mutex_add_waiter() when we race with + * ww_mutex_set_context_fastpath(). In that case we'll get here again + * through __ww_mutex_check_waiters(). + */ + if (!hold_ctx) + return false; + + /* + * Can have !owner because of __mutex_unlock_slowpath(), but if owner, + * it cannot go away because we'll have FLAG_WAITERS set and hold + * wait_lock. + */ + if (!owner) + return false; + + if (ww_ctx->acquired > 0 && __ww_ctx_less(hold_ctx, ww_ctx)) { + hold_ctx->wounded = 1; + + /* + * wake_up_process() paired with set_current_state() + * inserts sufficient barriers to make sure @owner either sees + * it's wounded in __ww_mutex_check_kill() or has a + * wakeup pending to re-read the wounded state. + */ + if (owner != current) + wake_up_process(owner); + + return true; + } + + return false; +} + +/* + * We just acquired @lock under @ww_ctx, if there are more important contexts + * waiting behind us on the wait-list, check if they need to die, or wound us. + * + * See __ww_mutex_add_waiter() for the list-order construction; basically the + * list is ordered by stamp, smallest (oldest) first. + * + * This relies on never mixing wait-die/wound-wait on the same wait-list; + * which is currently ensured by that being a ww_class property. + * + * The current task must not be on the wait list. + */ +static void +__ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx) +{ + struct MUTEX_WAITER *cur; + + lockdep_assert_wait_lock_held(lock); + + for (cur = __ww_waiter_first(lock); cur; + cur = __ww_waiter_next(lock, cur)) { + + if (!cur->ww_ctx) + continue; + + if (__ww_mutex_die(lock, cur, ww_ctx) || + __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx)) + break; + } +} + +/* + * After acquiring lock with fastpath, where we do not hold wait_lock, set ctx + * and wake up any waiters so they can recheck. + */ +static __always_inline void +ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + ww_mutex_lock_acquired(lock, ctx); + + /* + * The lock->ctx update should be visible on all cores before + * the WAITERS check is done, otherwise contended waiters might be + * missed. The contended waiters will either see ww_ctx == NULL + * and keep spinning, or it will acquire wait_lock, add itself + * to waiter list and sleep. + */ + smp_mb(); /* See comments above and below. */ + + /* + * [W] ww->ctx = ctx [W] MUTEX_FLAG_WAITERS + * MB MB + * [R] MUTEX_FLAG_WAITERS [R] ww->ctx + * + * The memory barrier above pairs with the memory barrier in + * __ww_mutex_add_waiter() and makes sure we either observe ww->ctx + * and/or !empty list. + */ + if (likely(!__ww_mutex_has_waiters(&lock->base))) + return; + + /* + * Uh oh, we raced in fastpath, check if any of the waiters need to + * die or wound us. + */ + lock_wait_lock(&lock->base); + __ww_mutex_check_waiters(&lock->base, ctx); + unlock_wait_lock(&lock->base); +} + +static __always_inline int +__ww_mutex_kill(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx) +{ + if (ww_ctx->acquired > 0) { +#ifdef DEBUG_WW_MUTEXES + struct ww_mutex *ww; + + ww = container_of(lock, struct ww_mutex, base); + DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock); + ww_ctx->contending_lock = ww; +#endif + return -EDEADLK; + } + + return 0; +} + +/* + * Check the wound condition for the current lock acquire. + * + * Wound-Wait: If we're wounded, kill ourself. + * + * Wait-Die: If we're trying to acquire a lock already held by an older + * context, kill ourselves. + * + * Since __ww_mutex_add_waiter() orders the wait-list on stamp, we only have to + * look at waiters before us in the wait-list. + */ +static inline int +__ww_mutex_check_kill(struct MUTEX *lock, struct MUTEX_WAITER *waiter, + struct ww_acquire_ctx *ctx) +{ + struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); + struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx); + struct MUTEX_WAITER *cur; + + if (ctx->acquired == 0) + return 0; + + if (!ctx->is_wait_die) { + if (ctx->wounded) + return __ww_mutex_kill(lock, ctx); + + return 0; + } + + if (hold_ctx && __ww_ctx_less(ctx, hold_ctx)) + return __ww_mutex_kill(lock, ctx); + + /* + * If there is a waiter in front of us that has a context, then its + * stamp is earlier than ours and we must kill ourself. + */ + for (cur = __ww_waiter_prev(lock, waiter); cur; + cur = __ww_waiter_prev(lock, cur)) { + + if (!cur->ww_ctx) + continue; + + return __ww_mutex_kill(lock, ctx); + } + + return 0; +} + +/* + * Add @waiter to the wait-list, keep the wait-list ordered by stamp, smallest + * first. Such that older contexts are preferred to acquire the lock over + * younger contexts. + * + * Waiters without context are interspersed in FIFO order. + * + * Furthermore, for Wait-Die kill ourself immediately when possible (there are + * older contexts already waiting) to avoid unnecessary waiting and for + * Wound-Wait ensure we wound the owning context when it is younger. + */ +static inline int +__ww_mutex_add_waiter(struct MUTEX_WAITER *waiter, + struct MUTEX *lock, + struct ww_acquire_ctx *ww_ctx) +{ + struct MUTEX_WAITER *cur, *pos = NULL; + bool is_wait_die; + + if (!ww_ctx) { + __ww_waiter_add(lock, waiter, NULL); + return 0; + } + + is_wait_die = ww_ctx->is_wait_die; + + /* + * Add the waiter before the first waiter with a higher stamp. + * Waiters without a context are skipped to avoid starving + * them. Wait-Die waiters may die here. Wound-Wait waiters + * never die here, but they are sorted in stamp order and + * may wound the lock holder. + */ + for (cur = __ww_waiter_last(lock); cur; + cur = __ww_waiter_prev(lock, cur)) { + + if (!cur->ww_ctx) + continue; + + if (__ww_ctx_less(ww_ctx, cur->ww_ctx)) { + /* + * Wait-Die: if we find an older context waiting, there + * is no point in queueing behind it, as we'd have to + * die the moment it would acquire the lock. + */ + if (is_wait_die) { + int ret = __ww_mutex_kill(lock, ww_ctx); + + if (ret) + return ret; + } + + break; + } + + pos = cur; + + /* Wait-Die: ensure younger waiters die. */ + __ww_mutex_die(lock, cur, ww_ctx); + } + + __ww_waiter_add(lock, waiter, pos); + + /* + * Wound-Wait: if we're blocking on a mutex owned by a younger context, + * wound that such that we might proceed. + */ + if (!is_wait_die) { + struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); + + /* + * See ww_mutex_set_context_fastpath(). Orders setting + * MUTEX_FLAG_WAITERS vs the ww->ctx load, + * such that either we or the fastpath will wound @ww->ctx. + */ + smp_mb(); + __ww_mutex_wound(lock, ww_ctx, ww->ctx); + } + + return 0; +} + +static inline void __ww_mutex_unlock(struct ww_mutex *lock) +{ + if (lock->ctx) { +#ifdef DEBUG_WW_MUTEXES + DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired); +#endif + if (lock->ctx->acquired > 0) + lock->ctx->acquired--; + lock->ctx = NULL; + } +} diff --git a/kernel/locking/ww_rt_mutex.c b/kernel/locking/ww_rt_mutex.c new file mode 100644 index 000000000000..3f1fff7d2780 --- /dev/null +++ b/kernel/locking/ww_rt_mutex.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtmutex API + */ +#include <linux/spinlock.h> +#include <linux/export.h> + +#define RT_MUTEX_BUILD_MUTEX +#define WW_RT +#include "rtmutex.c" + +static int __sched +__ww_rt_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx, + unsigned int state, unsigned long ip) +{ + struct lockdep_map __maybe_unused *nest_lock = NULL; + struct rt_mutex *rtm = &lock->base; + int ret; + + might_sleep(); + + if (ww_ctx) { + if (unlikely(ww_ctx == READ_ONCE(lock->ctx))) + return -EALREADY; + + /* + * Reset the wounded flag after a kill. No other process can + * race and wound us here, since they can't have a valid owner + * pointer if we don't have any locks held. + */ + if (ww_ctx->acquired == 0) + ww_ctx->wounded = 0; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + nest_lock = &ww_ctx->dep_map; +#endif + } + mutex_acquire_nest(&rtm->dep_map, 0, 0, nest_lock, ip); + + if (likely(rt_mutex_cmpxchg_acquire(&rtm->rtmutex, NULL, current))) { + if (ww_ctx) + ww_mutex_set_context_fastpath(lock, ww_ctx); + return 0; + } + + ret = rt_mutex_slowlock(&rtm->rtmutex, ww_ctx, state); + + if (ret) + mutex_release(&rtm->dep_map, ip); + return ret; +} + +int __sched +ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + return __ww_rt_mutex_lock(lock, ctx, TASK_UNINTERRUPTIBLE, _RET_IP_); +} +EXPORT_SYMBOL(ww_mutex_lock); + +int __sched +ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + return __ww_rt_mutex_lock(lock, ctx, TASK_INTERRUPTIBLE, _RET_IP_); +} +EXPORT_SYMBOL(ww_mutex_lock_interruptible); + +void __sched ww_mutex_unlock(struct ww_mutex *lock) +{ + struct rt_mutex *rtm = &lock->base; + + __ww_mutex_unlock(lock); + + mutex_release(&rtm->dep_map, _RET_IP_); + __rt_mutex_unlock(&rtm->rtmutex); +} +EXPORT_SYMBOL(ww_mutex_unlock); diff --git a/kernel/module.c b/kernel/module.c index ed13917ea5f3..5c26a76e800b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3355,6 +3355,11 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(unsigned long), &mod->num_kprobe_blacklist); #endif +#ifdef CONFIG_PRINTK_INDEX + mod->printk_index_start = section_objs(info, ".printk_index", + sizeof(*mod->printk_index_start), + &mod->printk_index_size); +#endif #ifdef CONFIG_HAVE_STATIC_CALL_INLINE mod->static_call_sites = section_objs(info, ".static_call_sites", sizeof(*mod->static_call_sites), @@ -4484,8 +4489,10 @@ static void cfi_init(struct module *mod) /* Fix init/exit functions to point to the CFI jump table */ if (init) mod->init = *init; +#ifdef CONFIG_MODULE_UNLOAD if (exit) mod->exit = *exit; +#endif cfi_module_add(mod, module_addr_min); #endif diff --git a/kernel/notifier.c b/kernel/notifier.c index 1b019cbca594..b8251dc0bc0f 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -172,25 +172,6 @@ int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, } EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); -int atomic_notifier_call_chain_robust(struct atomic_notifier_head *nh, - unsigned long val_up, unsigned long val_down, void *v) -{ - unsigned long flags; - int ret; - - /* - * Musn't use RCU; because then the notifier list can - * change between the up and down traversal. - */ - spin_lock_irqsave(&nh->lock, flags); - ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v); - spin_unlock_irqrestore(&nh->lock, flags); - - return ret; -} -EXPORT_SYMBOL_GPL(atomic_notifier_call_chain_robust); -NOKPROBE_SYMBOL(atomic_notifier_call_chain_robust); - /** * atomic_notifier_call_chain - Call functions in an atomic notifier chain * @nh: Pointer to head of the atomic notifier chain diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index abc01fcad8c7..eec72ca962e2 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -568,6 +568,6 @@ out: int __init nsproxy_cache_init(void) { - nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); + nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC|SLAB_ACCOUNT); return 0; } diff --git a/kernel/padata.c b/kernel/padata.c index d4d3ba6e1728..18d3a5c699d8 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -9,19 +9,6 @@ * * Copyright (c) 2020 Oracle and/or its affiliates. * Author: Daniel Jordan <daniel.m.jordan@oracle.com> - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. */ #include <linux/completion.h> @@ -211,7 +198,7 @@ int padata_do_parallel(struct padata_shell *ps, if ((pinst->flags & PADATA_RESET)) goto out; - atomic_inc(&pd->refcnt); + refcount_inc(&pd->refcnt); padata->pd = pd; padata->cb_cpu = *cb_cpu; @@ -383,7 +370,7 @@ static void padata_serial_worker(struct work_struct *serial_work) } local_bh_enable(); - if (atomic_sub_and_test(cnt, &pd->refcnt)) + if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } @@ -593,7 +580,7 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps) padata_init_reorder_list(pd); padata_init_squeues(pd); pd->seq_nr = -1; - atomic_set(&pd->refcnt, 1); + refcount_set(&pd->refcnt, 1); spin_lock_init(&pd->lock); pd->cpu = cpumask_first(pd->cpumask.pcpu); INIT_WORK(&pd->reorder_work, invoke_padata_reorder); @@ -667,7 +654,7 @@ static int padata_replace(struct padata_instance *pinst) synchronize_rcu(); list_for_each_entry_continue_reverse(ps, &pinst->pslist, list) - if (atomic_dec_and_test(&ps->opd->refcnt)) + if (refcount_dec_and_test(&ps->opd->refcnt)) padata_free_pd(ps->opd); pinst->flags &= ~PADATA_RESET; @@ -733,7 +720,7 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, struct cpumask *serial_mask, *parallel_mask; int err = -EINVAL; - get_online_cpus(); + cpus_read_lock(); mutex_lock(&pinst->lock); switch (cpumask_type) { @@ -753,7 +740,7 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, out: mutex_unlock(&pinst->lock); - put_online_cpus(); + cpus_read_unlock(); return err; } @@ -992,7 +979,7 @@ struct padata_instance *padata_alloc(const char *name) if (!pinst->parallel_wq) goto err_free_inst; - get_online_cpus(); + cpus_read_lock(); pinst->serial_wq = alloc_workqueue("%s_serial", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE, 1, name); @@ -1026,7 +1013,7 @@ struct padata_instance *padata_alloc(const char *name) &pinst->cpu_dead_node); #endif - put_online_cpus(); + cpus_read_unlock(); return pinst; @@ -1036,7 +1023,7 @@ err_free_masks: err_free_serial_wq: destroy_workqueue(pinst->serial_wq); err_put_cpus: - put_online_cpus(); + cpus_read_unlock(); destroy_workqueue(pinst->parallel_wq); err_free_inst: kfree(pinst); @@ -1074,9 +1061,9 @@ struct padata_shell *padata_alloc_shell(struct padata_instance *pinst) ps->pinst = pinst; - get_online_cpus(); + cpus_read_lock(); pd = padata_alloc_pd(ps); - put_online_cpus(); + cpus_read_unlock(); if (!pd) goto out_free_ps; diff --git a/kernel/panic.c b/kernel/panic.c index edad89660a2b..cefd7d82366f 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -248,7 +248,6 @@ void panic(const char *fmt, ...) * Bypass the panic_cpu check and call __crash_kexec directly. */ if (!_crash_kexec_post_notifiers) { - printk_safe_flush_on_panic(); __crash_kexec(NULL); /* @@ -272,8 +271,6 @@ void panic(const char *fmt, ...) */ atomic_notifier_call_chain(&panic_notifier_list, 0, buf); - /* Call flush even twice. It tries harder with a single online CPU */ - printk_safe_flush_on_panic(); kmsg_dump(KMSG_DUMP_PANIC); /* diff --git a/kernel/params.c b/kernel/params.c index 2daa2780a92c..8299bd764e42 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -243,6 +243,24 @@ STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul); STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull); STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x", kstrtouint); +int param_set_uint_minmax(const char *val, const struct kernel_param *kp, + unsigned int min, unsigned int max) +{ + unsigned int num; + int ret; + + if (!val) + return -EINVAL; + ret = kstrtouint(val, 0, &num); + if (ret) + return ret; + if (num < min || num > max) + return -EINVAL; + *((unsigned int *)kp->arg) = num; + return 0; +} +EXPORT_SYMBOL_GPL(param_set_uint_minmax); + int param_set_charp(const char *val, const struct kernel_param *kp) { if (strlen(val) > 1024) { diff --git a/kernel/pid.c b/kernel/pid.c index ebdf9c60cd0b..efe87db44683 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -550,13 +550,21 @@ struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags) * Note, that this function can only be called after the fd table has * been unshared to avoid leaking the pidfd to the new process. * + * This symbol should not be explicitly exported to loadable modules. + * * Return: On success, a cloexec pidfd is returned. * On error, a negative errno number will be returned. */ -static int pidfd_create(struct pid *pid, unsigned int flags) +int pidfd_create(struct pid *pid, unsigned int flags) { int fd; + if (!pid || !pid_has_task(pid, PIDTYPE_TGID)) + return -EINVAL; + + if (flags & ~(O_NONBLOCK | O_RDWR | O_CLOEXEC)) + return -EINVAL; + fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid), flags | O_RDWR | O_CLOEXEC); if (fd < 0) @@ -596,10 +604,7 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags) if (!p) return -ESRCH; - if (pid_has_task(p, PIDTYPE_TGID)) - fd = pidfd_create(p, flags); - else - fd = -EINVAL; + fd = pidfd_create(p, flags); put_pid(p); return fd; diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index ca43239a255a..a46a3723bc66 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -51,7 +51,8 @@ static struct kmem_cache *create_pid_cachep(unsigned int level) mutex_lock(&pid_caches_mutex); /* Name collision forces to do allocation under mutex. */ if (!*pkc) - *pkc = kmem_cache_create(name, len, 0, SLAB_HWCACHE_ALIGN, 0); + *pkc = kmem_cache_create(name, len, 0, + SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 0); mutex_unlock(&pid_caches_mutex); /* current can fail, but someone else can succeed. */ return READ_ONCE(*pkc); @@ -449,7 +450,7 @@ const struct proc_ns_operations pidns_for_children_operations = { static __init int pid_namespaces_init(void) { - pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC); + pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC | SLAB_ACCOUNT); #ifdef CONFIG_CHECKPOINT_RESTORE register_sysctl_paths(kern_path, pid_ns_ctl_table); diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 0f4530b3a8cd..a332ccd829e2 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -170,7 +170,9 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, /* Compute the cost of each performance state. */ fmax = (u64) table[nr_states - 1].frequency; for (i = 0; i < nr_states; i++) { - table[i].cost = div64_u64(fmax * table[i].power, + unsigned long power_res = em_scale_power(table[i].power); + + table[i].cost = div64_u64(fmax * power_res, table[i].frequency); } diff --git a/kernel/power/main.c b/kernel/power/main.c index 12c7e1bb442f..44169f3081fd 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -577,7 +577,7 @@ static inline void pm_print_times_init(void) {} struct kobject *power_kobj; -/** +/* * state - control system sleep states. * * show() returns available sleep state labels, which may be "mem", "standby", diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index d8cae434f9eb..eb75f394a059 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -96,7 +96,7 @@ static void s2idle_enter(void) s2idle_state = S2IDLE_STATE_ENTER; raw_spin_unlock_irq(&s2idle_lock); - get_online_cpus(); + cpus_read_lock(); cpuidle_resume(); /* Push all the CPUs into the idle loop. */ @@ -106,7 +106,7 @@ static void s2idle_enter(void) s2idle_state == S2IDLE_STATE_WAKE); cpuidle_pause(); - put_online_cpus(); + cpus_read_unlock(); raw_spin_lock_irq(&s2idle_lock); diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c index e1ed58adb69e..d20526c5be15 100644 --- a/kernel/power/suspend_test.c +++ b/kernel/power/suspend_test.c @@ -129,7 +129,7 @@ static int __init has_wakealarm(struct device *dev, const void *data) { struct rtc_device *candidate = to_rtc_device(dev); - if (!candidate->ops->set_alarm) + if (!test_bit(RTC_FEATURE_ALARM, candidate->features)) return 0; if (!device_may_wakeup(candidate->dev.parent)) return 0; diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile index eee3dc9b60a9..d118739874c0 100644 --- a/kernel/printk/Makefile +++ b/kernel/printk/Makefile @@ -3,3 +3,4 @@ obj-y = printk.o obj-$(CONFIG_PRINTK) += printk_safe.o obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille.o obj-$(CONFIG_PRINTK) += printk_ringbuffer.o +obj-$(CONFIG_PRINTK_INDEX) += index.o diff --git a/kernel/printk/index.c b/kernel/printk/index.c new file mode 100644 index 000000000000..d3709408debe --- /dev/null +++ b/kernel/printk/index.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Userspace indexing of printk formats + */ + +#include <linux/debugfs.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/string_helpers.h> + +#include "internal.h" + +extern struct pi_entry *__start_printk_index[]; +extern struct pi_entry *__stop_printk_index[]; + +/* The base dir for module formats, typically debugfs/printk/index/ */ +static struct dentry *dfs_index; + +static struct pi_entry *pi_get_entry(const struct module *mod, loff_t pos) +{ + struct pi_entry **entries; + unsigned int nr_entries; + +#ifdef CONFIG_MODULES + if (mod) { + entries = mod->printk_index_start; + nr_entries = mod->printk_index_size; + } +#endif + + if (!mod) { + /* vmlinux, comes from linker symbols */ + entries = __start_printk_index; + nr_entries = __stop_printk_index - __start_printk_index; + } + + if (pos >= nr_entries) + return NULL; + + return entries[pos]; +} + +static void *pi_next(struct seq_file *s, void *v, loff_t *pos) +{ + const struct module *mod = s->file->f_inode->i_private; + struct pi_entry *entry = pi_get_entry(mod, *pos); + + (*pos)++; + + return entry; +} + +static void *pi_start(struct seq_file *s, loff_t *pos) +{ + /* + * Make show() print the header line. Do not update *pos because + * pi_next() still has to return the entry at index 0 later. + */ + if (*pos == 0) + return SEQ_START_TOKEN; + + return pi_next(s, NULL, pos); +} + +/* + * We need both ESCAPE_ANY and explicit characters from ESCAPE_SPECIAL in @only + * because otherwise ESCAPE_NAP will cause double quotes and backslashes to be + * ignored for quoting. + */ +#define seq_escape_printf_format(s, src) \ + seq_escape_str(s, src, ESCAPE_ANY | ESCAPE_NAP | ESCAPE_APPEND, "\"\\") + +static int pi_show(struct seq_file *s, void *v) +{ + const struct pi_entry *entry = v; + int level = LOGLEVEL_DEFAULT; + enum printk_info_flags flags = 0; + u16 prefix_len = 0; + + if (v == SEQ_START_TOKEN) { + seq_puts(s, "# <level/flags> filename:line function \"format\"\n"); + return 0; + } + + if (!entry->fmt) + return 0; + + if (entry->level) + printk_parse_prefix(entry->level, &level, &flags); + else + prefix_len = printk_parse_prefix(entry->fmt, &level, &flags); + + + if (flags & LOG_CONT) { + /* + * LOGLEVEL_DEFAULT here means "use the same level as the + * message we're continuing from", not the default message + * loglevel, so don't display it as such. + */ + if (level == LOGLEVEL_DEFAULT) + seq_puts(s, "<c>"); + else + seq_printf(s, "<%d,c>", level); + } else + seq_printf(s, "<%d>", level); + + seq_printf(s, " %s:%d %s \"", entry->file, entry->line, entry->func); + if (entry->subsys_fmt_prefix) + seq_escape_printf_format(s, entry->subsys_fmt_prefix); + seq_escape_printf_format(s, entry->fmt + prefix_len); + seq_puts(s, "\"\n"); + + return 0; +} + +static void pi_stop(struct seq_file *p, void *v) { } + +static const struct seq_operations dfs_index_sops = { + .start = pi_start, + .next = pi_next, + .show = pi_show, + .stop = pi_stop, +}; + +DEFINE_SEQ_ATTRIBUTE(dfs_index); + +#ifdef CONFIG_MODULES +static const char *pi_get_module_name(struct module *mod) +{ + return mod ? mod->name : "vmlinux"; +} +#else +static const char *pi_get_module_name(struct module *mod) +{ + return "vmlinux"; +} +#endif + +static void pi_create_file(struct module *mod) +{ + debugfs_create_file(pi_get_module_name(mod), 0444, dfs_index, + mod, &dfs_index_fops); +} + +#ifdef CONFIG_MODULES +static void pi_remove_file(struct module *mod) +{ + debugfs_remove(debugfs_lookup(pi_get_module_name(mod), dfs_index)); +} + +static int pi_module_notify(struct notifier_block *nb, unsigned long op, + void *data) +{ + struct module *mod = data; + + switch (op) { + case MODULE_STATE_COMING: + pi_create_file(mod); + break; + case MODULE_STATE_GOING: + pi_remove_file(mod); + break; + default: /* we don't care about other module states */ + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block module_printk_fmts_nb = { + .notifier_call = pi_module_notify, +}; + +static void __init pi_setup_module_notifier(void) +{ + register_module_notifier(&module_printk_fmts_nb); +} +#else +static inline void __init pi_setup_module_notifier(void) { } +#endif + +static int __init pi_init(void) +{ + struct dentry *dfs_root = debugfs_create_dir("printk", NULL); + + dfs_index = debugfs_create_dir("index", dfs_root); + pi_setup_module_notifier(); + pi_create_file(NULL); + + return 0; +} + +/* debugfs comes up on core and must be initialised first */ +postcore_initcall(pi_init); diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 51615c909b2f..9f3ed2fdb721 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -6,11 +6,11 @@ #ifdef CONFIG_PRINTK -#define PRINTK_SAFE_CONTEXT_MASK 0x007ffffff -#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x008000000 -#define PRINTK_NMI_CONTEXT_MASK 0xff0000000 - -#define PRINTK_NMI_CONTEXT_OFFSET 0x010000000 +/* Flags for a single printk record. */ +enum printk_info_flags { + LOG_NEWLINE = 2, /* text ended with a newline */ + LOG_CONT = 8, /* text is a fragment of a continuation line */ +}; __printf(4, 0) int vprintk_store(int facility, int level, @@ -19,10 +19,7 @@ int vprintk_store(int facility, int level, __printf(1, 0) int vprintk_default(const char *fmt, va_list args); __printf(1, 0) int vprintk_deferred(const char *fmt, va_list args); -void __printk_safe_enter(void); -void __printk_safe_exit(void); -void printk_safe_init(void); bool printk_percpu_data_ready(void); #define printk_safe_enter_irqsave(flags) \ @@ -37,20 +34,10 @@ bool printk_percpu_data_ready(void); local_irq_restore(flags); \ } while (0) -#define printk_safe_enter_irq() \ - do { \ - local_irq_disable(); \ - __printk_safe_enter(); \ - } while (0) - -#define printk_safe_exit_irq() \ - do { \ - __printk_safe_exit(); \ - local_irq_enable(); \ - } while (0) - void defer_console_output(void); +u16 printk_parse_prefix(const char *text, int *level, + enum printk_info_flags *flags); #else /* @@ -61,9 +48,5 @@ void defer_console_output(void); #define printk_safe_enter_irqsave(flags) local_irq_save(flags) #define printk_safe_exit_irqrestore(flags) local_irq_restore(flags) -#define printk_safe_enter_irq() local_irq_disable() -#define printk_safe_exit_irq() local_irq_enable() - -static inline void printk_safe_init(void) { } static inline bool printk_percpu_data_ready(void) { return false; } #endif /* CONFIG_PRINTK */ diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 142a58d124d9..a8d0a58deebc 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -350,13 +350,8 @@ static int console_msg_format = MSG_FORMAT_DEFAULT; * non-prinatable characters are escaped in the "\xff" notation. */ -enum log_flags { - LOG_NEWLINE = 2, /* text ended with a newline */ - LOG_CONT = 8, /* text is a fragment of a continuation line */ -}; - /* syslog_lock protects syslog_* variables and write access to clear_seq. */ -static DEFINE_RAW_SPINLOCK(syslog_lock); +static DEFINE_MUTEX(syslog_lock); #ifdef CONFIG_PRINTK DECLARE_WAIT_QUEUE_HEAD(log_wait); @@ -732,27 +727,22 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf, if (ret) return ret; - printk_safe_enter_irq(); if (!prb_read_valid(prb, atomic64_read(&user->seq), r)) { if (file->f_flags & O_NONBLOCK) { ret = -EAGAIN; - printk_safe_exit_irq(); goto out; } - printk_safe_exit_irq(); ret = wait_event_interruptible(log_wait, prb_read_valid(prb, atomic64_read(&user->seq), r)); if (ret) goto out; - printk_safe_enter_irq(); } if (r->info->seq != atomic64_read(&user->seq)) { /* our last seen message is gone, return error and reset */ atomic64_set(&user->seq, r->info->seq); ret = -EPIPE; - printk_safe_exit_irq(); goto out; } @@ -762,7 +752,6 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf, &r->info->dev_info); atomic64_set(&user->seq, r->info->seq + 1); - printk_safe_exit_irq(); if (len > count) { ret = -EINVAL; @@ -797,7 +786,6 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence) if (offset) return -ESPIPE; - printk_safe_enter_irq(); switch (whence) { case SEEK_SET: /* the first record */ @@ -818,7 +806,6 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence) default: ret = -EINVAL; } - printk_safe_exit_irq(); return ret; } @@ -833,7 +820,6 @@ static __poll_t devkmsg_poll(struct file *file, poll_table *wait) poll_wait(file, &log_wait, wait); - printk_safe_enter_irq(); if (prb_read_valid_info(prb, atomic64_read(&user->seq), &info, NULL)) { /* return error when data has vanished underneath us */ if (info.seq != atomic64_read(&user->seq)) @@ -841,7 +827,6 @@ static __poll_t devkmsg_poll(struct file *file, poll_table *wait) else ret = EPOLLIN|EPOLLRDNORM; } - printk_safe_exit_irq(); return ret; } @@ -874,9 +859,7 @@ static int devkmsg_open(struct inode *inode, struct file *file) prb_rec_init_rd(&user->record, &user->info, &user->text_buf[0], sizeof(user->text_buf)); - printk_safe_enter_irq(); atomic64_set(&user->seq, prb_first_valid_seq(prb)); - printk_safe_exit_irq(); file->private_data = user; return 0; @@ -1042,9 +1025,6 @@ static inline void log_buf_add_cpu(void) {} static void __init set_percpu_data_ready(void) { - printk_safe_init(); - /* Make sure we set this flag only after printk_safe() init is done */ - barrier(); __printk_percpu_data_ready = true; } @@ -1082,6 +1062,7 @@ void __init setup_log_buf(int early) struct prb_desc *new_descs; struct printk_info info; struct printk_record r; + unsigned int text_size; size_t new_descs_size; size_t new_infos_size; unsigned long flags; @@ -1142,24 +1123,37 @@ void __init setup_log_buf(int early) new_descs, ilog2(new_descs_count), new_infos); - printk_safe_enter_irqsave(flags); + local_irq_save(flags); log_buf_len = new_log_buf_len; log_buf = new_log_buf; new_log_buf_len = 0; free = __LOG_BUF_LEN; - prb_for_each_record(0, &printk_rb_static, seq, &r) - free -= add_to_rb(&printk_rb_dynamic, &r); + prb_for_each_record(0, &printk_rb_static, seq, &r) { + text_size = add_to_rb(&printk_rb_dynamic, &r); + if (text_size > free) + free = 0; + else + free -= text_size; + } - /* - * This is early enough that everything is still running on the - * boot CPU and interrupts are disabled. So no new messages will - * appear during the transition to the dynamic buffer. - */ prb = &printk_rb_dynamic; - printk_safe_exit_irqrestore(flags); + local_irq_restore(flags); + + /* + * Copy any remaining messages that might have appeared from + * NMI context after copying but before switching to the + * dynamic buffer. + */ + prb_for_each_record(seq, &printk_rb_static, seq, &r) { + text_size = add_to_rb(&printk_rb_dynamic, &r); + if (text_size > free) + free = 0; + else + free -= text_size; + } if (seq != prb_next_seq(&printk_rb_static)) { pr_err("dropped %llu messages\n", @@ -1172,9 +1166,9 @@ void __init setup_log_buf(int early) return; err_free_descs: - memblock_free(__pa(new_descs), new_descs_size); + memblock_free_ptr(new_descs, new_descs_size); err_free_log_buf: - memblock_free(__pa(new_log_buf), new_log_buf_len); + memblock_free_ptr(new_log_buf, new_log_buf_len); } static bool __read_mostly ignore_loglevel; @@ -1481,12 +1475,14 @@ static u64 find_first_fitting_seq(u64 start_seq, u64 max_seq, size_t size, return seq; } +/* The caller is responsible for making sure @size is greater than 0. */ static int syslog_print(char __user *buf, int size) { struct printk_info info; struct printk_record r; char *text; int len = 0; + u64 seq; text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL); if (!text) @@ -1494,17 +1490,35 @@ static int syslog_print(char __user *buf, int size) prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX); - while (size > 0) { + mutex_lock(&syslog_lock); + + /* + * Wait for the @syslog_seq record to be available. @syslog_seq may + * change while waiting. + */ + do { + seq = syslog_seq; + + mutex_unlock(&syslog_lock); + len = wait_event_interruptible(log_wait, prb_read_valid(prb, seq, NULL)); + mutex_lock(&syslog_lock); + + if (len) + goto out; + } while (syslog_seq != seq); + + /* + * Copy records that fit into the buffer. The above cycle makes sure + * that the first record is always available. + */ + do { size_t n; size_t skip; + int err; - printk_safe_enter_irq(); - raw_spin_lock(&syslog_lock); - if (!prb_read_valid(prb, syslog_seq, &r)) { - raw_spin_unlock(&syslog_lock); - printk_safe_exit_irq(); + if (!prb_read_valid(prb, syslog_seq, &r)) break; - } + if (r.info->seq != syslog_seq) { /* message is gone, move to next valid one */ syslog_seq = r.info->seq; @@ -1531,13 +1545,15 @@ static int syslog_print(char __user *buf, int size) syslog_partial += n; } else n = 0; - raw_spin_unlock(&syslog_lock); - printk_safe_exit_irq(); if (!n) break; - if (copy_to_user(buf, text + skip, n)) { + mutex_unlock(&syslog_lock); + err = copy_to_user(buf, text + skip, n); + mutex_lock(&syslog_lock); + + if (err) { if (!len) len = -EFAULT; break; @@ -1546,8 +1562,9 @@ static int syslog_print(char __user *buf, int size) len += n; size -= n; buf += n; - } - + } while (size); +out: + mutex_unlock(&syslog_lock); kfree(text); return len; } @@ -1566,7 +1583,6 @@ static int syslog_print_all(char __user *buf, int size, bool clear) return -ENOMEM; time = printk_time; - printk_safe_enter_irq(); /* * Find first record that fits, including all following records, * into the user-provided buffer for this dump. @@ -1587,23 +1603,20 @@ static int syslog_print_all(char __user *buf, int size, bool clear) break; } - printk_safe_exit_irq(); if (copy_to_user(buf + len, text, textlen)) len = -EFAULT; else len += textlen; - printk_safe_enter_irq(); if (len < 0) break; } if (clear) { - raw_spin_lock(&syslog_lock); + mutex_lock(&syslog_lock); latched_seq_write(&clear_seq, seq); - raw_spin_unlock(&syslog_lock); + mutex_unlock(&syslog_lock); } - printk_safe_exit_irq(); kfree(text); return len; @@ -1611,23 +1624,9 @@ static int syslog_print_all(char __user *buf, int size, bool clear) static void syslog_clear(void) { - printk_safe_enter_irq(); - raw_spin_lock(&syslog_lock); + mutex_lock(&syslog_lock); latched_seq_write(&clear_seq, prb_next_seq(prb)); - raw_spin_unlock(&syslog_lock); - printk_safe_exit_irq(); -} - -/* Return a consistent copy of @syslog_seq. */ -static u64 read_syslog_seq_irq(void) -{ - u64 seq; - - raw_spin_lock_irq(&syslog_lock); - seq = syslog_seq; - raw_spin_unlock_irq(&syslog_lock); - - return seq; + mutex_unlock(&syslog_lock); } int do_syslog(int type, char __user *buf, int len, int source) @@ -1653,11 +1652,6 @@ int do_syslog(int type, char __user *buf, int len, int source) return 0; if (!access_ok(buf, len)) return -EFAULT; - - error = wait_event_interruptible(log_wait, - prb_read_valid(prb, read_syslog_seq_irq(), NULL)); - if (error) - return error; error = syslog_print(buf, len); break; /* Read/clear last kernel messages */ @@ -1703,12 +1697,10 @@ int do_syslog(int type, char __user *buf, int len, int source) break; /* Number of chars in the log buffer */ case SYSLOG_ACTION_SIZE_UNREAD: - printk_safe_enter_irq(); - raw_spin_lock(&syslog_lock); + mutex_lock(&syslog_lock); if (!prb_read_valid_info(prb, syslog_seq, &info, NULL)) { /* No unread messages. */ - raw_spin_unlock(&syslog_lock); - printk_safe_exit_irq(); + mutex_unlock(&syslog_lock); return 0; } if (info.seq != syslog_seq) { @@ -1736,8 +1728,7 @@ int do_syslog(int type, char __user *buf, int len, int source) } error -= syslog_partial; } - raw_spin_unlock(&syslog_lock); - printk_safe_exit_irq(); + mutex_unlock(&syslog_lock); break; /* Size of the log buffer */ case SYSLOG_ACTION_SIZE_BUFFER: @@ -1940,6 +1931,76 @@ static void call_console_drivers(const char *ext_text, size_t ext_len, } } +/* + * Recursion is tracked separately on each CPU. If NMIs are supported, an + * additional NMI context per CPU is also separately tracked. Until per-CPU + * is available, a separate "early tracking" is performed. + */ +static DEFINE_PER_CPU(u8, printk_count); +static u8 printk_count_early; +#ifdef CONFIG_HAVE_NMI +static DEFINE_PER_CPU(u8, printk_count_nmi); +static u8 printk_count_nmi_early; +#endif + +/* + * Recursion is limited to keep the output sane. printk() should not require + * more than 1 level of recursion (allowing, for example, printk() to trigger + * a WARN), but a higher value is used in case some printk-internal errors + * exist, such as the ringbuffer validation checks failing. + */ +#define PRINTK_MAX_RECURSION 3 + +/* + * Return a pointer to the dedicated counter for the CPU+context of the + * caller. + */ +static u8 *__printk_recursion_counter(void) +{ +#ifdef CONFIG_HAVE_NMI + if (in_nmi()) { + if (printk_percpu_data_ready()) + return this_cpu_ptr(&printk_count_nmi); + return &printk_count_nmi_early; + } +#endif + if (printk_percpu_data_ready()) + return this_cpu_ptr(&printk_count); + return &printk_count_early; +} + +/* + * Enter recursion tracking. Interrupts are disabled to simplify tracking. + * The caller must check the boolean return value to see if the recursion is + * allowed. On failure, interrupts are not disabled. + * + * @recursion_ptr must be a variable of type (u8 *) and is the same variable + * that is passed to printk_exit_irqrestore(). + */ +#define printk_enter_irqsave(recursion_ptr, flags) \ +({ \ + bool success = true; \ + \ + typecheck(u8 *, recursion_ptr); \ + local_irq_save(flags); \ + (recursion_ptr) = __printk_recursion_counter(); \ + if (*(recursion_ptr) > PRINTK_MAX_RECURSION) { \ + local_irq_restore(flags); \ + success = false; \ + } else { \ + (*(recursion_ptr))++; \ + } \ + success; \ +}) + +/* Exit recursion tracking, restoring interrupts. */ +#define printk_exit_irqrestore(recursion_ptr, flags) \ + do { \ + typecheck(u8 *, recursion_ptr); \ + (*(recursion_ptr))--; \ + local_irq_restore(flags); \ + } while (0) + int printk_delay_msec __read_mostly; static inline void printk_delay(void) @@ -1961,23 +2022,24 @@ static inline u32 printk_caller_id(void) } /** - * parse_prefix - Parse level and control flags. + * printk_parse_prefix - Parse level and control flags. * * @text: The terminated text message. * @level: A pointer to the current level value, will be updated. - * @lflags: A pointer to the current log flags, will be updated. + * @flags: A pointer to the current printk_info flags, will be updated. * * @level may be NULL if the caller is not interested in the parsed value. * Otherwise the variable pointed to by @level must be set to * LOGLEVEL_DEFAULT in order to be updated with the parsed value. * - * @lflags may be NULL if the caller is not interested in the parsed value. - * Otherwise the variable pointed to by @lflags will be OR'd with the parsed + * @flags may be NULL if the caller is not interested in the parsed value. + * Otherwise the variable pointed to by @flags will be OR'd with the parsed * value. * * Return: The length of the parsed level and control flags. */ -static u16 parse_prefix(char *text, int *level, enum log_flags *lflags) +u16 printk_parse_prefix(const char *text, int *level, + enum printk_info_flags *flags) { u16 prefix_len = 0; int kern_level; @@ -1993,8 +2055,8 @@ static u16 parse_prefix(char *text, int *level, enum log_flags *lflags) *level = kern_level - '0'; break; case 'c': /* KERN_CONT */ - if (lflags) - *lflags |= LOG_CONT; + if (flags) + *flags |= LOG_CONT; } prefix_len += 2; @@ -2004,8 +2066,9 @@ static u16 parse_prefix(char *text, int *level, enum log_flags *lflags) return prefix_len; } -static u16 printk_sprint(char *text, u16 size, int facility, enum log_flags *lflags, - const char *fmt, va_list args) +static u16 printk_sprint(char *text, u16 size, int facility, + enum printk_info_flags *flags, const char *fmt, + va_list args) { u16 text_len; @@ -2014,14 +2077,14 @@ static u16 printk_sprint(char *text, u16 size, int facility, enum log_flags *lfl /* Mark and strip a trailing newline. */ if (text_len && text[text_len - 1] == '\n') { text_len--; - *lflags |= LOG_NEWLINE; + *flags |= LOG_NEWLINE; } /* Strip log level and control flags. */ if (facility == 0) { u16 prefix_len; - prefix_len = parse_prefix(text, NULL, NULL); + prefix_len = printk_parse_prefix(text, NULL, NULL); if (prefix_len) { text_len -= prefix_len; memmove(text, text + prefix_len, text_len); @@ -2038,13 +2101,16 @@ int vprintk_store(int facility, int level, { const u32 caller_id = printk_caller_id(); struct prb_reserved_entry e; - enum log_flags lflags = 0; + enum printk_info_flags flags = 0; struct printk_record r; + unsigned long irqflags; u16 trunc_msg_len = 0; char prefix_buf[8]; + u8 *recursion_ptr; u16 reserve_size; va_list args2; u16 text_len; + int ret = 0; u64 ts_nsec; /* @@ -2055,6 +2121,9 @@ int vprintk_store(int facility, int level, */ ts_nsec = local_clock(); + if (!printk_enter_irqsave(recursion_ptr, irqflags)) + return 0; + /* * The sprintf needs to come first since the syslog prefix might be * passed in as a parameter. An extra byte must be reserved so that @@ -2070,29 +2139,30 @@ int vprintk_store(int facility, int level, /* Extract log level or control flags. */ if (facility == 0) - parse_prefix(&prefix_buf[0], &level, &lflags); + printk_parse_prefix(&prefix_buf[0], &level, &flags); if (level == LOGLEVEL_DEFAULT) level = default_message_loglevel; if (dev_info) - lflags |= LOG_NEWLINE; + flags |= LOG_NEWLINE; - if (lflags & LOG_CONT) { + if (flags & LOG_CONT) { prb_rec_init_wr(&r, reserve_size); if (prb_reserve_in_last(&e, prb, &r, caller_id, LOG_LINE_MAX)) { text_len = printk_sprint(&r.text_buf[r.info->text_len], reserve_size, - facility, &lflags, fmt, args); + facility, &flags, fmt, args); r.info->text_len += text_len; - if (lflags & LOG_NEWLINE) { + if (flags & LOG_NEWLINE) { r.info->flags |= LOG_NEWLINE; prb_final_commit(&e); } else { prb_commit(&e); } - return text_len; + ret = text_len; + goto out; } } @@ -2108,29 +2178,32 @@ int vprintk_store(int facility, int level, prb_rec_init_wr(&r, reserve_size + trunc_msg_len); if (!prb_reserve(&e, prb, &r)) - return 0; + goto out; } /* fill message */ - text_len = printk_sprint(&r.text_buf[0], reserve_size, facility, &lflags, fmt, args); + text_len = printk_sprint(&r.text_buf[0], reserve_size, facility, &flags, fmt, args); if (trunc_msg_len) memcpy(&r.text_buf[text_len], trunc_msg, trunc_msg_len); r.info->text_len = text_len + trunc_msg_len; r.info->facility = facility; r.info->level = level & 7; - r.info->flags = lflags & 0x1f; + r.info->flags = flags & 0x1f; r.info->ts_nsec = ts_nsec; r.info->caller_id = caller_id; if (dev_info) memcpy(&r.info->dev_info, dev_info, sizeof(r.info->dev_info)); /* A message without a trailing newline can be continued. */ - if (!(lflags & LOG_NEWLINE)) + if (!(flags & LOG_NEWLINE)) prb_commit(&e); else prb_final_commit(&e); - return (text_len + trunc_msg_len); + ret = text_len + trunc_msg_len; +out: + printk_exit_irqrestore(recursion_ptr, irqflags); + return ret; } asmlinkage int vprintk_emit(int facility, int level, @@ -2139,7 +2212,6 @@ asmlinkage int vprintk_emit(int facility, int level, { int printed_len; bool in_sched = false; - unsigned long flags; /* Suppress unimportant messages after panic happens */ if (unlikely(suppress_printk)) @@ -2153,9 +2225,7 @@ asmlinkage int vprintk_emit(int facility, int level, boot_delay_msec(level); printk_delay(); - printk_safe_enter_irqsave(flags); printed_len = vprintk_store(facility, level, dev_info, fmt, args); - printk_safe_exit_irqrestore(flags); /* If called from the scheduler, we can not call up(). */ if (!in_sched) { @@ -2186,28 +2256,7 @@ int vprintk_default(const char *fmt, va_list args) } EXPORT_SYMBOL_GPL(vprintk_default); -/** - * printk - print a kernel message - * @fmt: format string - * - * This is printk(). It can be called from any context. We want it to work. - * - * We try to grab the console_lock. If we succeed, it's easy - we log the - * output and call the console drivers. If we fail to get the semaphore, we - * place the output into the log buffer and return. The current holder of - * the console_sem will notice the new output in console_unlock(); and will - * send it to the consoles before releasing the lock. - * - * One effect of this deferred printing is that code which calls printk() and - * then changes console_loglevel may break. This is because console_loglevel - * is inspected when the actual printing occurs. - * - * See also: - * printf(3) - * - * See the vsnprintf() documentation for format string extensions over C99. - */ -asmlinkage __visible int printk(const char *fmt, ...) +asmlinkage __visible int _printk(const char *fmt, ...) { va_list args; int r; @@ -2218,7 +2267,7 @@ asmlinkage __visible int printk(const char *fmt, ...) return r; } -EXPORT_SYMBOL(printk); +EXPORT_SYMBOL(_printk); #else /* CONFIG_PRINTK */ @@ -2404,6 +2453,18 @@ module_param_named(console_suspend, console_suspend_enabled, MODULE_PARM_DESC(console_suspend, "suspend console during suspend" " and hibernate operations"); +static bool printk_console_no_auto_verbose; + +void console_verbose(void) +{ + if (console_loglevel && !printk_console_no_auto_verbose) + console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH; +} +EXPORT_SYMBOL_GPL(console_verbose); + +module_param_named(console_no_auto_verbose, printk_console_no_auto_verbose, bool, 0644); +MODULE_PARM_DESC(console_no_auto_verbose, "Disable console loglevel raise to highest on oops/panic/etc"); + /** * suspend_console - suspend the console subsystem * @@ -2545,6 +2606,7 @@ void console_unlock(void) bool do_cond_resched, retry; struct printk_info info; struct printk_record r; + u64 __maybe_unused next_seq; if (console_suspended) { up_console_sem(); @@ -2584,9 +2646,9 @@ again: for (;;) { size_t ext_len = 0; + int handover; size_t len; - printk_safe_enter_irqsave(flags); skip: if (!prb_read_valid(prb, console_seq, &r)) break; @@ -2636,26 +2698,31 @@ skip: * were to occur on another CPU, it may wait for this one to * finish. This task can not be preempted if there is a * waiter waiting to take over. + * + * Interrupts are disabled because the hand over to a waiter + * must not be interrupted until the hand over is completed + * (@console_waiter is cleared). */ + printk_safe_enter_irqsave(flags); console_lock_spinning_enable(); stop_critical_timings(); /* don't trace print latency */ call_console_drivers(ext_text, ext_len, text, len); start_critical_timings(); - if (console_lock_spinning_disable_and_check()) { - printk_safe_exit_irqrestore(flags); - return; - } - + handover = console_lock_spinning_disable_and_check(); printk_safe_exit_irqrestore(flags); + if (handover) + return; if (do_cond_resched) cond_resched(); } - console_locked = 0; + /* Get consistent value of the next-to-be-used sequence number. */ + next_seq = console_seq; + console_locked = 0; up_console_sem(); /* @@ -2664,9 +2731,7 @@ skip: * there's a new owner and the console_unlock() from them will do the * flush, no worries. */ - retry = prb_read_valid(prb, console_seq, NULL); - printk_safe_exit_irqrestore(flags); - + retry = prb_read_valid(prb, next_seq, NULL); if (retry && console_trylock()) goto again; } @@ -2728,13 +2793,8 @@ void console_flush_on_panic(enum con_flush_mode mode) console_trylock(); console_may_schedule = 0; - if (mode == CONSOLE_REPLAY_ALL) { - unsigned long flags; - - printk_safe_enter_irqsave(flags); + if (mode == CONSOLE_REPLAY_ALL) console_seq = prb_first_valid_seq(prb); - printk_safe_exit_irqrestore(flags); - } console_unlock(); } @@ -2869,7 +2929,6 @@ static int try_enable_new_console(struct console *newcon, bool user_specified) */ void register_console(struct console *newcon) { - unsigned long flags; struct console *bcon = NULL; int err; @@ -2974,9 +3033,9 @@ void register_console(struct console *newcon) exclusive_console_stop_seq = console_seq; /* Get a consistent copy of @syslog_seq. */ - raw_spin_lock_irqsave(&syslog_lock, flags); + mutex_lock(&syslog_lock); console_seq = syslog_seq; - raw_spin_unlock_irqrestore(&syslog_lock, flags); + mutex_unlock(&syslog_lock); } console_unlock(); console_sysfs_notify(); @@ -3203,7 +3262,7 @@ int vprintk_deferred(const char *fmt, va_list args) return r; } -int printk_deferred(const char *fmt, ...) +int _printk_deferred(const char *fmt, ...) { va_list args; int r; @@ -3386,14 +3445,12 @@ bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog, struct printk_info info; unsigned int line_count; struct printk_record r; - unsigned long flags; size_t l = 0; bool ret = false; if (iter->cur_seq < min_seq) iter->cur_seq = min_seq; - printk_safe_enter_irqsave(flags); prb_rec_init_rd(&r, &info, line, size); /* Read text or count text lines? */ @@ -3414,7 +3471,6 @@ bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog, iter->cur_seq = r.info->seq + 1; ret = true; out: - printk_safe_exit_irqrestore(flags); if (len) *len = l; return ret; @@ -3446,7 +3502,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog, u64 min_seq = latched_seq_read_nolock(&clear_seq); struct printk_info info; struct printk_record r; - unsigned long flags; u64 seq; u64 next_seq; size_t len = 0; @@ -3459,7 +3514,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog, if (iter->cur_seq < min_seq) iter->cur_seq = min_seq; - printk_safe_enter_irqsave(flags); if (prb_read_valid_info(prb, iter->cur_seq, &info, NULL)) { if (info.seq != iter->cur_seq) { /* messages are gone, move to first available one */ @@ -3468,10 +3522,8 @@ bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog, } /* last entry */ - if (iter->cur_seq >= iter->next_seq) { - printk_safe_exit_irqrestore(flags); + if (iter->cur_seq >= iter->next_seq) goto out; - } /* * Find first record that fits, including all following records, @@ -3503,7 +3555,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog, iter->next_seq = next_seq; ret = true; - printk_safe_exit_irqrestore(flags); out: if (len_out) *len_out = len; @@ -3521,12 +3572,8 @@ EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer); */ void kmsg_dump_rewind(struct kmsg_dump_iter *iter) { - unsigned long flags; - - printk_safe_enter_irqsave(flags); iter->cur_seq = latched_seq_read_nolock(&clear_seq); iter->next_seq = prb_next_seq(prb); - printk_safe_exit_irqrestore(flags); } EXPORT_SYMBOL_GPL(kmsg_dump_rewind); diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 94232186fccb..ef0f9a2044da 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -4,347 +4,16 @@ */ #include <linux/preempt.h> -#include <linux/spinlock.h> -#include <linux/debug_locks.h> #include <linux/kdb.h> #include <linux/smp.h> #include <linux/cpumask.h> -#include <linux/irq_work.h> #include <linux/printk.h> #include <linux/kprobes.h> #include "internal.h" -/* - * In NMI and safe mode, printk() avoids taking locks. Instead, - * it uses an alternative implementation that temporary stores - * the strings into a per-CPU buffer. The content of the buffer - * is later flushed into the main ring buffer via IRQ work. - * - * The alternative implementation is chosen transparently - * by examining current printk() context mask stored in @printk_context - * per-CPU variable. - * - * The implementation allows to flush the strings also from another CPU. - * There are situations when we want to make sure that all buffers - * were handled or when IRQs are blocked. - */ - -#define SAFE_LOG_BUF_LEN ((1 << CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT) - \ - sizeof(atomic_t) - \ - sizeof(atomic_t) - \ - sizeof(struct irq_work)) - -struct printk_safe_seq_buf { - atomic_t len; /* length of written data */ - atomic_t message_lost; - struct irq_work work; /* IRQ work that flushes the buffer */ - unsigned char buffer[SAFE_LOG_BUF_LEN]; -}; - -static DEFINE_PER_CPU(struct printk_safe_seq_buf, safe_print_seq); static DEFINE_PER_CPU(int, printk_context); -static DEFINE_RAW_SPINLOCK(safe_read_lock); - -#ifdef CONFIG_PRINTK_NMI -static DEFINE_PER_CPU(struct printk_safe_seq_buf, nmi_print_seq); -#endif - -/* Get flushed in a more safe context. */ -static void queue_flush_work(struct printk_safe_seq_buf *s) -{ - if (printk_percpu_data_ready()) - irq_work_queue(&s->work); -} - -/* - * Add a message to per-CPU context-dependent buffer. NMI and printk-safe - * have dedicated buffers, because otherwise printk-safe preempted by - * NMI-printk would have overwritten the NMI messages. - * - * The messages are flushed from irq work (or from panic()), possibly, - * from other CPU, concurrently with printk_safe_log_store(). Should this - * happen, printk_safe_log_store() will notice the buffer->len mismatch - * and repeat the write. - */ -static __printf(2, 0) int printk_safe_log_store(struct printk_safe_seq_buf *s, - const char *fmt, va_list args) -{ - int add; - size_t len; - va_list ap; - -again: - len = atomic_read(&s->len); - - /* The trailing '\0' is not counted into len. */ - if (len >= sizeof(s->buffer) - 1) { - atomic_inc(&s->message_lost); - queue_flush_work(s); - return 0; - } - - /* - * Make sure that all old data have been read before the buffer - * was reset. This is not needed when we just append data. - */ - if (!len) - smp_rmb(); - - va_copy(ap, args); - add = vscnprintf(s->buffer + len, sizeof(s->buffer) - len, fmt, ap); - va_end(ap); - if (!add) - return 0; - - /* - * Do it once again if the buffer has been flushed in the meantime. - * Note that atomic_cmpxchg() is an implicit memory barrier that - * makes sure that the data were written before updating s->len. - */ - if (atomic_cmpxchg(&s->len, len, len + add) != len) - goto again; - - queue_flush_work(s); - return add; -} - -static inline void printk_safe_flush_line(const char *text, int len) -{ - /* - * Avoid any console drivers calls from here, because we may be - * in NMI or printk_safe context (when in panic). The messages - * must go only into the ring buffer at this stage. Consoles will - * get explicitly called later when a crashdump is not generated. - */ - printk_deferred("%.*s", len, text); -} - -/* printk part of the temporary buffer line by line */ -static int printk_safe_flush_buffer(const char *start, size_t len) -{ - const char *c, *end; - bool header; - - c = start; - end = start + len; - header = true; - - /* Print line by line. */ - while (c < end) { - if (*c == '\n') { - printk_safe_flush_line(start, c - start + 1); - start = ++c; - header = true; - continue; - } - - /* Handle continuous lines or missing new line. */ - if ((c + 1 < end) && printk_get_level(c)) { - if (header) { - c = printk_skip_level(c); - continue; - } - - printk_safe_flush_line(start, c - start); - start = c++; - header = true; - continue; - } - - header = false; - c++; - } - - /* Check if there was a partial line. Ignore pure header. */ - if (start < end && !header) { - static const char newline[] = KERN_CONT "\n"; - - printk_safe_flush_line(start, end - start); - printk_safe_flush_line(newline, strlen(newline)); - } - - return len; -} - -static void report_message_lost(struct printk_safe_seq_buf *s) -{ - int lost = atomic_xchg(&s->message_lost, 0); - - if (lost) - printk_deferred("Lost %d message(s)!\n", lost); -} - -/* - * Flush data from the associated per-CPU buffer. The function - * can be called either via IRQ work or independently. - */ -static void __printk_safe_flush(struct irq_work *work) -{ - struct printk_safe_seq_buf *s = - container_of(work, struct printk_safe_seq_buf, work); - unsigned long flags; - size_t len; - int i; - - /* - * The lock has two functions. First, one reader has to flush all - * available message to make the lockless synchronization with - * writers easier. Second, we do not want to mix messages from - * different CPUs. This is especially important when printing - * a backtrace. - */ - raw_spin_lock_irqsave(&safe_read_lock, flags); - - i = 0; -more: - len = atomic_read(&s->len); - - /* - * This is just a paranoid check that nobody has manipulated - * the buffer an unexpected way. If we printed something then - * @len must only increase. Also it should never overflow the - * buffer size. - */ - if ((i && i >= len) || len > sizeof(s->buffer)) { - const char *msg = "printk_safe_flush: internal error\n"; - - printk_safe_flush_line(msg, strlen(msg)); - len = 0; - } - - if (!len) - goto out; /* Someone else has already flushed the buffer. */ - - /* Make sure that data has been written up to the @len */ - smp_rmb(); - i += printk_safe_flush_buffer(s->buffer + i, len - i); - - /* - * Check that nothing has got added in the meantime and truncate - * the buffer. Note that atomic_cmpxchg() is an implicit memory - * barrier that makes sure that the data were copied before - * updating s->len. - */ - if (atomic_cmpxchg(&s->len, len, 0) != len) - goto more; - -out: - report_message_lost(s); - raw_spin_unlock_irqrestore(&safe_read_lock, flags); -} - -/** - * printk_safe_flush - flush all per-cpu nmi buffers. - * - * The buffers are flushed automatically via IRQ work. This function - * is useful only when someone wants to be sure that all buffers have - * been flushed at some point. - */ -void printk_safe_flush(void) -{ - int cpu; - - for_each_possible_cpu(cpu) { -#ifdef CONFIG_PRINTK_NMI - __printk_safe_flush(&per_cpu(nmi_print_seq, cpu).work); -#endif - __printk_safe_flush(&per_cpu(safe_print_seq, cpu).work); - } -} - -/** - * printk_safe_flush_on_panic - flush all per-cpu nmi buffers when the system - * goes down. - * - * Similar to printk_safe_flush() but it can be called even in NMI context when - * the system goes down. It does the best effort to get NMI messages into - * the main ring buffer. - * - * Note that it could try harder when there is only one CPU online. - */ -void printk_safe_flush_on_panic(void) -{ - /* - * Make sure that we could access the safe buffers. - * Do not risk a double release when more CPUs are up. - */ - if (raw_spin_is_locked(&safe_read_lock)) { - if (num_online_cpus() > 1) - return; - - debug_locks_off(); - raw_spin_lock_init(&safe_read_lock); - } - - printk_safe_flush(); -} - -#ifdef CONFIG_PRINTK_NMI -/* - * Safe printk() for NMI context. It uses a per-CPU buffer to - * store the message. NMIs are not nested, so there is always only - * one writer running. But the buffer might get flushed from another - * CPU, so we need to be careful. - */ -static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args) -{ - struct printk_safe_seq_buf *s = this_cpu_ptr(&nmi_print_seq); - - return printk_safe_log_store(s, fmt, args); -} - -void noinstr printk_nmi_enter(void) -{ - this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -void noinstr printk_nmi_exit(void) -{ - this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET); -} - -/* - * Marks a code that might produce many messages in NMI context - * and the risk of losing them is more critical than eventual - * reordering. - * - * It has effect only when called in NMI context. Then printk() - * will store the messages into the main logbuf directly. - */ -void printk_nmi_direct_enter(void) -{ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - this_cpu_or(printk_context, PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -void printk_nmi_direct_exit(void) -{ - this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK); -} - -#else - -static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args) -{ - return 0; -} - -#endif /* CONFIG_PRINTK_NMI */ - -/* - * Lock-less printk(), to avoid deadlocks should the printk() recurse - * into itself. It uses a per-CPU buffer to store the message, just like - * NMI. - */ -static __printf(1, 0) int vprintk_safe(const char *fmt, va_list args) -{ - struct printk_safe_seq_buf *s = this_cpu_ptr(&safe_print_seq); - - return printk_safe_log_store(s, fmt, args); -} - /* Can be preempted by NMI. */ void __printk_safe_enter(void) { @@ -369,46 +38,15 @@ asmlinkage int vprintk(const char *fmt, va_list args) * Use the main logbuf even in NMI. But avoid calling console * drivers that might have their own locks. */ - if ((this_cpu_read(printk_context) & PRINTK_NMI_DIRECT_CONTEXT_MASK)) { - unsigned long flags; + if (this_cpu_read(printk_context) || in_nmi()) { int len; - printk_safe_enter_irqsave(flags); len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, fmt, args); - printk_safe_exit_irqrestore(flags); defer_console_output(); return len; } - /* Use extra buffer in NMI. */ - if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK) - return vprintk_nmi(fmt, args); - - /* Use extra buffer to prevent a recursion deadlock in safe mode. */ - if (this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK) - return vprintk_safe(fmt, args); - /* No obstacles. */ return vprintk_default(fmt, args); } EXPORT_SYMBOL(vprintk); - -void __init printk_safe_init(void) -{ - int cpu; - - for_each_possible_cpu(cpu) { - struct printk_safe_seq_buf *s; - - s = &per_cpu(safe_print_seq, cpu); - init_irq_work(&s->work, __printk_safe_flush); - -#ifdef CONFIG_PRINTK_NMI - s = &per_cpu(nmi_print_seq, cpu); - init_irq_work(&s->work, __printk_safe_flush); -#endif - } - - /* Flush pending messages that did not have scheduled IRQ works. */ - printk_safe_flush(); -} diff --git a/kernel/profile.c b/kernel/profile.c index c2ebddb5e974..eb9c7f0f5ac5 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -41,7 +41,8 @@ struct profile_hit { #define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) static atomic_t *prof_buffer; -static unsigned long prof_len, prof_shift; +static unsigned long prof_len; +static unsigned short int prof_shift; int prof_on __read_mostly; EXPORT_SYMBOL_GPL(prof_on); @@ -67,8 +68,8 @@ int profile_setup(char *str) if (str[strlen(sleepstr)] == ',') str += strlen(sleepstr) + 1; if (get_option(&str, &par)) - prof_shift = par; - pr_info("kernel sleep profiling enabled (shift: %ld)\n", + prof_shift = clamp(par, 0, BITS_PER_LONG - 1); + pr_info("kernel sleep profiling enabled (shift: %u)\n", prof_shift); #else pr_warn("kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); @@ -78,21 +79,21 @@ int profile_setup(char *str) if (str[strlen(schedstr)] == ',') str += strlen(schedstr) + 1; if (get_option(&str, &par)) - prof_shift = par; - pr_info("kernel schedule profiling enabled (shift: %ld)\n", + prof_shift = clamp(par, 0, BITS_PER_LONG - 1); + pr_info("kernel schedule profiling enabled (shift: %u)\n", prof_shift); } else if (!strncmp(str, kvmstr, strlen(kvmstr))) { prof_on = KVM_PROFILING; if (str[strlen(kvmstr)] == ',') str += strlen(kvmstr) + 1; if (get_option(&str, &par)) - prof_shift = par; - pr_info("kernel KVM profiling enabled (shift: %ld)\n", + prof_shift = clamp(par, 0, BITS_PER_LONG - 1); + pr_info("kernel KVM profiling enabled (shift: %u)\n", prof_shift); } else if (get_option(&str, &par)) { - prof_shift = par; + prof_shift = clamp(par, 0, BITS_PER_LONG - 1); prof_on = CPU_PROFILING; - pr_info("kernel profiling enabled (shift: %ld)\n", + pr_info("kernel profiling enabled (shift: %u)\n", prof_shift); } return 1; @@ -468,7 +469,7 @@ read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) unsigned long p = *ppos; ssize_t read; char *pnt; - unsigned int sample_step = 1 << prof_shift; + unsigned long sample_step = 1UL << prof_shift; profile_flip_buffers(); if (p >= (prof_len+1)*sizeof(unsigned int)) diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index dca51fe9c73f..2cc34a22a506 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -487,7 +487,7 @@ retry: if (gp_async) { cur_ops->gp_barrier(); } - writer_n_durations[me] = i_max; + writer_n_durations[me] = i_max + 1; torture_kthread_stopping("rcu_scale_writer"); return 0; } @@ -561,7 +561,7 @@ rcu_scale_cleanup(void) wdpp = writer_durations[i]; if (!wdpp) continue; - for (j = 0; j <= writer_n_durations[i]; j++) { + for (j = 0; j < writer_n_durations[i]; j++) { wdp = &wdpp[j]; pr_alert("%s%s %4d writer-duration: %5d %llu\n", scale_type, SCALE_FLAG, diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 40ef5417d954..ab4215266ebe 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2022,8 +2022,13 @@ static int rcu_torture_stall(void *args) __func__, raw_smp_processor_id()); while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), stop_at)) - if (stall_cpu_block) + if (stall_cpu_block) { +#ifdef CONFIG_PREEMPTION + preempt_schedule(); +#else schedule_timeout_uninterruptible(HZ); +#endif + } if (stall_cpu_irqsoff) local_irq_enable(); else if (!stall_cpu_block) diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index d998a76fb542..66dc14cf5687 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -467,6 +467,40 @@ static struct ref_scale_ops acqrel_ops = { .name = "acqrel" }; +static volatile u64 stopopts; + +static void ref_clock_section(const int nloops) +{ + u64 x = 0; + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) + x += ktime_get_real_fast_ns(); + preempt_enable(); + stopopts = x; +} + +static void ref_clock_delay_section(const int nloops, const int udl, const int ndl) +{ + u64 x = 0; + int i; + + preempt_disable(); + for (i = nloops; i >= 0; i--) { + x += ktime_get_real_fast_ns(); + un_delay(udl, ndl); + } + preempt_enable(); + stopopts = x; +} + +static struct ref_scale_ops clock_ops = { + .readsection = ref_clock_section, + .delaysection = ref_clock_delay_section, + .name = "clock" +}; + static void rcu_scale_one_reader(void) { if (readdelay <= 0) @@ -759,7 +793,7 @@ ref_scale_init(void) int firsterr = 0; static struct ref_scale_ops *scale_ops[] = { &rcu_ops, &srcu_ops, &rcu_trace_ops, &rcu_tasks_ops, &refcnt_ops, &rwlock_ops, - &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, + &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, &clock_ops, }; if (!torture_init_begin(scale_type, verbose)) diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 26344dc6483b..a0ba2ed49bc6 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -96,7 +96,7 @@ EXPORT_SYMBOL_GPL(cleanup_srcu_struct); */ void __srcu_read_unlock(struct srcu_struct *ssp, int idx) { - int newval = ssp->srcu_lock_nesting[idx] - 1; + int newval = READ_ONCE(ssp->srcu_lock_nesting[idx]) - 1; WRITE_ONCE(ssp->srcu_lock_nesting[idx], newval); if (!newval && READ_ONCE(ssp->srcu_gp_waiting)) diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 8536c55df514..806160c44b17 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -643,8 +643,8 @@ void exit_tasks_rcu_finish(void) { exit_tasks_rcu_finish_trace(current); } // // "Rude" variant of Tasks RCU, inspired by Steve Rostedt's trick of // passing an empty function to schedule_on_each_cpu(). This approach -// provides an asynchronous call_rcu_tasks_rude() API and batching -// of concurrent calls to the synchronous synchronize_rcu_rude() API. +// provides an asynchronous call_rcu_tasks_rude() API and batching of +// concurrent calls to the synchronous synchronize_rcu_tasks_rude() API. // This invokes schedule_on_each_cpu() in order to send IPIs far and wide // and induces otherwise unnecessary context switches on all online CPUs, // whether idle or not. @@ -785,7 +785,10 @@ EXPORT_SYMBOL_GPL(show_rcu_tasks_rude_gp_kthread); // set that task's .need_qs flag so that task's next outermost // rcu_read_unlock_trace() will report the quiescent state (in which // case the count of readers is incremented). If both attempts fail, -// the task is added to a "holdout" list. +// the task is added to a "holdout" list. Note that IPIs are used +// to invoke trc_read_check_handler() in the context of running tasks +// in order to avoid ordering overhead on common-case shared-variable +// accessses. // rcu_tasks_trace_postscan(): // Initialize state and attempt to identify an immediate quiescent // state as above (but only for idle tasks), unblock CPU-hotplug @@ -847,7 +850,7 @@ static DEFINE_IRQ_WORK(rcu_tasks_trace_iw, rcu_read_unlock_iw); /* If we are the last reader, wake up the grace-period kthread. */ void rcu_read_unlock_trace_special(struct task_struct *t, int nesting) { - int nq = t->trc_reader_special.b.need_qs; + int nq = READ_ONCE(t->trc_reader_special.b.need_qs); if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB) && t->trc_reader_special.b.need_mb) @@ -894,7 +897,7 @@ static void trc_read_check_handler(void *t_in) // If the task is not in a read-side critical section, and // if this is the last reader, awaken the grace-period kthread. - if (likely(!t->trc_reader_nesting)) { + if (likely(!READ_ONCE(t->trc_reader_nesting))) { if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end))) wake_up(&trc_wait); // Mark as checked after decrement to avoid false @@ -903,7 +906,7 @@ static void trc_read_check_handler(void *t_in) goto reset_ipi; } // If we are racing with an rcu_read_unlock_trace(), try again later. - if (unlikely(t->trc_reader_nesting < 0)) { + if (unlikely(READ_ONCE(t->trc_reader_nesting) < 0)) { if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end))) wake_up(&trc_wait); goto reset_ipi; @@ -913,14 +916,14 @@ static void trc_read_check_handler(void *t_in) // Get here if the task is in a read-side critical section. Set // its state so that it will awaken the grace-period kthread upon // exit from that critical section. - WARN_ON_ONCE(t->trc_reader_special.b.need_qs); + WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs)); WRITE_ONCE(t->trc_reader_special.b.need_qs, true); reset_ipi: // Allow future IPIs to be sent on CPU and for task. // Also order this IPI handler against any later manipulations of // the intended task. - smp_store_release(&per_cpu(trc_ipi_to_cpu, smp_processor_id()), false); // ^^^ + smp_store_release(per_cpu_ptr(&trc_ipi_to_cpu, smp_processor_id()), false); // ^^^ smp_store_release(&texp->trc_ipi_to_cpu, -1); // ^^^ } @@ -950,6 +953,7 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) n_heavy_reader_ofl_updates++; in_qs = true; } else { + // The task is not running, so C-language access is safe. in_qs = likely(!t->trc_reader_nesting); } @@ -964,7 +968,7 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) // state so that it will awaken the grace-period kthread upon exit // from that critical section. atomic_inc(&trc_n_readers_need_end); // One more to wait on. - WARN_ON_ONCE(t->trc_reader_special.b.need_qs); + WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs)); WRITE_ONCE(t->trc_reader_special.b.need_qs, true); return true; } @@ -982,7 +986,7 @@ static void trc_wait_for_one_reader(struct task_struct *t, // The current task had better be in a quiescent state. if (t == current) { t->trc_reader_checked = true; - WARN_ON_ONCE(t->trc_reader_nesting); + WARN_ON_ONCE(READ_ONCE(t->trc_reader_nesting)); return; } @@ -994,6 +998,12 @@ static void trc_wait_for_one_reader(struct task_struct *t, } put_task_struct(t); + // If this task is not yet on the holdout list, then we are in + // an RCU read-side critical section. Otherwise, the invocation of + // rcu_add_holdout() that added it to the list did the necessary + // get_task_struct(). Either way, the task cannot be freed out + // from under this code. + // If currently running, send an IPI, either way, add to list. trc_add_holdout(t, bhp); if (task_curr(t) && @@ -1092,8 +1102,8 @@ static void show_stalled_task_trace(struct task_struct *t, bool *firstreport) ".I"[READ_ONCE(t->trc_ipi_to_cpu) > 0], ".i"[is_idle_task(t)], ".N"[cpu > 0 && tick_nohz_full_cpu(cpu)], - t->trc_reader_nesting, - " N"[!!t->trc_reader_special.b.need_qs], + READ_ONCE(t->trc_reader_nesting), + " N"[!!READ_ONCE(t->trc_reader_special.b.need_qs)], cpu); sched_show_task(t); } @@ -1187,7 +1197,7 @@ static void rcu_tasks_trace_postgp(struct rcu_tasks *rtp) static void exit_tasks_rcu_finish_trace(struct task_struct *t) { WRITE_ONCE(t->trc_reader_checked, true); - WARN_ON_ONCE(t->trc_reader_nesting); + WARN_ON_ONCE(READ_ONCE(t->trc_reader_nesting)); WRITE_ONCE(t->trc_reader_nesting, 0); if (WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs))) rcu_read_unlock_trace_special(t, 0); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 51f24ecd94b2..bce848e50512 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -74,17 +74,10 @@ /* Data structures. */ -/* - * Steal a bit from the bottom of ->dynticks for idle entry/exit - * control. Initially this is for TLB flushing. - */ -#define RCU_DYNTICK_CTRL_MASK 0x1 -#define RCU_DYNTICK_CTRL_CTR (RCU_DYNTICK_CTRL_MASK + 1) - static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, rcu_data) = { .dynticks_nesting = 1, .dynticks_nmi_nesting = DYNTICK_IRQ_NONIDLE, - .dynticks = ATOMIC_INIT(RCU_DYNTICK_CTRL_CTR), + .dynticks = ATOMIC_INIT(1), #ifdef CONFIG_RCU_NOCB_CPU .cblist.flags = SEGCBLIST_SOFTIRQ_ONLY, #endif @@ -259,6 +252,15 @@ void rcu_softirq_qs(void) } /* + * Increment the current CPU's rcu_data structure's ->dynticks field + * with ordering. Return the new value. + */ +static noinline noinstr unsigned long rcu_dynticks_inc(int incby) +{ + return arch_atomic_add_return(incby, this_cpu_ptr(&rcu_data.dynticks)); +} + +/* * Record entry into an extended quiescent state. This is only to be * called when not already in an extended quiescent state, that is, * RCU is watching prior to the call to this function and is no longer @@ -266,7 +268,6 @@ void rcu_softirq_qs(void) */ static noinstr void rcu_dynticks_eqs_enter(void) { - struct rcu_data *rdp = this_cpu_ptr(&rcu_data); int seq; /* @@ -275,13 +276,9 @@ static noinstr void rcu_dynticks_eqs_enter(void) * next idle sojourn. */ rcu_dynticks_task_trace_enter(); // Before ->dynticks update! - seq = arch_atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks); + seq = rcu_dynticks_inc(1); // RCU is no longer watching. Better be in extended quiescent state! - WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && - (seq & RCU_DYNTICK_CTRL_CTR)); - /* Better not have special action (TLB flush) pending! */ - WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && - (seq & RCU_DYNTICK_CTRL_MASK)); + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && (seq & 0x1)); } /* @@ -291,7 +288,6 @@ static noinstr void rcu_dynticks_eqs_enter(void) */ static noinstr void rcu_dynticks_eqs_exit(void) { - struct rcu_data *rdp = this_cpu_ptr(&rcu_data); int seq; /* @@ -299,15 +295,10 @@ static noinstr void rcu_dynticks_eqs_exit(void) * and we also must force ordering with the next RCU read-side * critical section. */ - seq = arch_atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks); + seq = rcu_dynticks_inc(1); // RCU is now watching. Better not be in an extended quiescent state! rcu_dynticks_task_trace_exit(); // After ->dynticks update! - WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && - !(seq & RCU_DYNTICK_CTRL_CTR)); - if (seq & RCU_DYNTICK_CTRL_MASK) { - arch_atomic_andnot(RCU_DYNTICK_CTRL_MASK, &rdp->dynticks); - smp_mb__after_atomic(); /* _exit after clearing mask. */ - } + WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !(seq & 0x1)); } /* @@ -324,9 +315,9 @@ static void rcu_dynticks_eqs_online(void) { struct rcu_data *rdp = this_cpu_ptr(&rcu_data); - if (atomic_read(&rdp->dynticks) & RCU_DYNTICK_CTRL_CTR) + if (atomic_read(&rdp->dynticks) & 0x1) return; - atomic_add(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks); + rcu_dynticks_inc(1); } /* @@ -336,9 +327,7 @@ static void rcu_dynticks_eqs_online(void) */ static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void) { - struct rcu_data *rdp = this_cpu_ptr(&rcu_data); - - return !(arch_atomic_read(&rdp->dynticks) & RCU_DYNTICK_CTRL_CTR); + return !(atomic_read(this_cpu_ptr(&rcu_data.dynticks)) & 0x1); } /* @@ -347,9 +336,8 @@ static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void) */ static int rcu_dynticks_snap(struct rcu_data *rdp) { - int snap = atomic_add_return(0, &rdp->dynticks); - - return snap & ~RCU_DYNTICK_CTRL_MASK; + smp_mb(); // Fundamental RCU ordering guarantee. + return atomic_read_acquire(&rdp->dynticks); } /* @@ -358,7 +346,7 @@ static int rcu_dynticks_snap(struct rcu_data *rdp) */ static bool rcu_dynticks_in_eqs(int snap) { - return !(snap & RCU_DYNTICK_CTRL_CTR); + return !(snap & 0x1); } /* Return true if the specified CPU is currently idle from an RCU viewpoint. */ @@ -389,8 +377,7 @@ bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) int snap; // If not quiescent, force back to earlier extended quiescent state. - snap = atomic_read(&rdp->dynticks) & ~(RCU_DYNTICK_CTRL_MASK | - RCU_DYNTICK_CTRL_CTR); + snap = atomic_read(&rdp->dynticks) & ~0x1; smp_rmb(); // Order ->dynticks and *vp reads. if (READ_ONCE(*vp)) @@ -398,32 +385,7 @@ bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) smp_rmb(); // Order *vp read and ->dynticks re-read. // If still in the same extended quiescent state, we are good! - return snap == (atomic_read(&rdp->dynticks) & ~RCU_DYNTICK_CTRL_MASK); -} - -/* - * Set the special (bottom) bit of the specified CPU so that it - * will take special action (such as flushing its TLB) on the - * next exit from an extended quiescent state. Returns true if - * the bit was successfully set, or false if the CPU was not in - * an extended quiescent state. - */ -bool rcu_eqs_special_set(int cpu) -{ - int old; - int new; - int new_old; - struct rcu_data *rdp = &per_cpu(rcu_data, cpu); - - new_old = atomic_read(&rdp->dynticks); - do { - old = new_old; - if (old & RCU_DYNTICK_CTRL_CTR) - return false; - new = old | RCU_DYNTICK_CTRL_MASK; - new_old = atomic_cmpxchg(&rdp->dynticks, old, new); - } while (new_old != old); - return true; + return snap == atomic_read(&rdp->dynticks); } /* @@ -439,13 +401,12 @@ bool rcu_eqs_special_set(int cpu) */ notrace void rcu_momentary_dyntick_idle(void) { - int special; + int seq; raw_cpu_write(rcu_data.rcu_need_heavy_qs, false); - special = atomic_add_return(2 * RCU_DYNTICK_CTRL_CTR, - &this_cpu_ptr(&rcu_data)->dynticks); + seq = rcu_dynticks_inc(2); /* It is illegal to call this from idle state. */ - WARN_ON_ONCE(!(special & RCU_DYNTICK_CTRL_CTR)); + WARN_ON_ONCE(!(seq & 0x1)); rcu_preempt_deferred_qs(current); } EXPORT_SYMBOL_GPL(rcu_momentary_dyntick_idle); @@ -1325,7 +1286,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) */ jtsq = READ_ONCE(jiffies_to_sched_qs); ruqp = per_cpu_ptr(&rcu_data.rcu_urgent_qs, rdp->cpu); - rnhqp = &per_cpu(rcu_data.rcu_need_heavy_qs, rdp->cpu); + rnhqp = per_cpu_ptr(&rcu_data.rcu_need_heavy_qs, rdp->cpu); if (!READ_ONCE(*rnhqp) && (time_after(jiffies, rcu_state.gp_start + jtsq * 2) || time_after(jiffies, rcu_state.jiffies_resched) || @@ -1772,7 +1733,7 @@ static void rcu_strict_gp_boundary(void *unused) /* * Initialize a new grace period. Return false if no grace period required. */ -static bool rcu_gp_init(void) +static noinline_for_stack bool rcu_gp_init(void) { unsigned long firstseq; unsigned long flags; @@ -1966,7 +1927,7 @@ static void rcu_gp_fqs(bool first_time) /* * Loop doing repeated quiescent-state forcing until the grace period ends. */ -static void rcu_gp_fqs_loop(void) +static noinline_for_stack void rcu_gp_fqs_loop(void) { bool first_gp_fqs; int gf = 0; @@ -1993,8 +1954,8 @@ static void rcu_gp_fqs_loop(void) trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq, TPS("fqswait")); WRITE_ONCE(rcu_state.gp_state, RCU_GP_WAIT_FQS); - ret = swait_event_idle_timeout_exclusive( - rcu_state.gp_wq, rcu_gp_fqs_check_wake(&gf), j); + (void)swait_event_idle_timeout_exclusive(rcu_state.gp_wq, + rcu_gp_fqs_check_wake(&gf), j); rcu_gp_torture_wait(); WRITE_ONCE(rcu_state.gp_state, RCU_GP_DOING_FQS); /* Locking provides needed memory barriers. */ @@ -2471,9 +2432,6 @@ int rcutree_dead_cpu(unsigned int cpu) WRITE_ONCE(rcu_state.n_online_cpus, rcu_state.n_online_cpus - 1); /* Adjust any no-longer-needed kthreads. */ rcu_boost_kthread_setaffinity(rnp, -1); - /* Do any needed no-CB deferred wakeups from this CPU. */ - do_nocb_deferred_wakeup(per_cpu_ptr(&rcu_data, cpu)); - // Stop-machine done, so allow nohz_full to disable tick. tick_dep_clear(TICK_DEP_BIT_RCU); return 0; @@ -4050,7 +4008,7 @@ void rcu_barrier(void) */ init_completion(&rcu_state.barrier_completion); atomic_set(&rcu_state.barrier_cpu_count, 2); - get_online_cpus(); + cpus_read_lock(); /* * Force each CPU with callbacks to register a new callback. @@ -4081,7 +4039,7 @@ void rcu_barrier(void) rcu_state.barrier_sequence); } } - put_online_cpus(); + cpus_read_unlock(); /* * Now that we have an rcu_barrier_callback() callback on each @@ -4784,4 +4742,5 @@ void __init rcu_init(void) #include "tree_stall.h" #include "tree_exp.h" +#include "tree_nocb.h" #include "tree_plugin.h" diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h new file mode 100644 index 000000000000..8fdf44f8523f --- /dev/null +++ b/kernel/rcu/tree_nocb.h @@ -0,0 +1,1496 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Read-Copy Update mechanism for mutual exclusion (tree-based version) + * Internal non-public definitions that provide either classic + * or preemptible semantics. + * + * Copyright Red Hat, 2009 + * Copyright IBM Corporation, 2009 + * Copyright SUSE, 2021 + * + * Author: Ingo Molnar <mingo@elte.hu> + * Paul E. McKenney <paulmck@linux.ibm.com> + * Frederic Weisbecker <frederic@kernel.org> + */ + +#ifdef CONFIG_RCU_NOCB_CPU +static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks offloaded. */ +static bool __read_mostly rcu_nocb_poll; /* Offload kthread are to poll. */ +static inline int rcu_lockdep_is_held_nocb(struct rcu_data *rdp) +{ + return lockdep_is_held(&rdp->nocb_lock); +} + +static inline bool rcu_current_is_nocb_kthread(struct rcu_data *rdp) +{ + /* Race on early boot between thread creation and assignment */ + if (!rdp->nocb_cb_kthread || !rdp->nocb_gp_kthread) + return true; + + if (current == rdp->nocb_cb_kthread || current == rdp->nocb_gp_kthread) + if (in_task()) + return true; + return false; +} + +/* + * Offload callback processing from the boot-time-specified set of CPUs + * specified by rcu_nocb_mask. For the CPUs in the set, there are kthreads + * created that pull the callbacks from the corresponding CPU, wait for + * a grace period to elapse, and invoke the callbacks. These kthreads + * are organized into GP kthreads, which manage incoming callbacks, wait for + * grace periods, and awaken CB kthreads, and the CB kthreads, which only + * invoke callbacks. Each GP kthread invokes its own CBs. The no-CBs CPUs + * do a wake_up() on their GP kthread when they insert a callback into any + * empty list, unless the rcu_nocb_poll boot parameter has been specified, + * in which case each kthread actively polls its CPU. (Which isn't so great + * for energy efficiency, but which does reduce RCU's overhead on that CPU.) + * + * This is intended to be used in conjunction with Frederic Weisbecker's + * adaptive-idle work, which would seriously reduce OS jitter on CPUs + * running CPU-bound user-mode computations. + * + * Offloading of callbacks can also be used as an energy-efficiency + * measure because CPUs with no RCU callbacks queued are more aggressive + * about entering dyntick-idle mode. + */ + + +/* + * Parse the boot-time rcu_nocb_mask CPU list from the kernel parameters. + * If the list is invalid, a warning is emitted and all CPUs are offloaded. + */ +static int __init rcu_nocb_setup(char *str) +{ + alloc_bootmem_cpumask_var(&rcu_nocb_mask); + if (cpulist_parse(str, rcu_nocb_mask)) { + pr_warn("rcu_nocbs= bad CPU range, all CPUs set\n"); + cpumask_setall(rcu_nocb_mask); + } + return 1; +} +__setup("rcu_nocbs=", rcu_nocb_setup); + +static int __init parse_rcu_nocb_poll(char *arg) +{ + rcu_nocb_poll = true; + return 0; +} +early_param("rcu_nocb_poll", parse_rcu_nocb_poll); + +/* + * Don't bother bypassing ->cblist if the call_rcu() rate is low. + * After all, the main point of bypassing is to avoid lock contention + * on ->nocb_lock, which only can happen at high call_rcu() rates. + */ +static int nocb_nobypass_lim_per_jiffy = 16 * 1000 / HZ; +module_param(nocb_nobypass_lim_per_jiffy, int, 0); + +/* + * Acquire the specified rcu_data structure's ->nocb_bypass_lock. If the + * lock isn't immediately available, increment ->nocb_lock_contended to + * flag the contention. + */ +static void rcu_nocb_bypass_lock(struct rcu_data *rdp) + __acquires(&rdp->nocb_bypass_lock) +{ + lockdep_assert_irqs_disabled(); + if (raw_spin_trylock(&rdp->nocb_bypass_lock)) + return; + atomic_inc(&rdp->nocb_lock_contended); + WARN_ON_ONCE(smp_processor_id() != rdp->cpu); + smp_mb__after_atomic(); /* atomic_inc() before lock. */ + raw_spin_lock(&rdp->nocb_bypass_lock); + smp_mb__before_atomic(); /* atomic_dec() after lock. */ + atomic_dec(&rdp->nocb_lock_contended); +} + +/* + * Spinwait until the specified rcu_data structure's ->nocb_lock is + * not contended. Please note that this is extremely special-purpose, + * relying on the fact that at most two kthreads and one CPU contend for + * this lock, and also that the two kthreads are guaranteed to have frequent + * grace-period-duration time intervals between successive acquisitions + * of the lock. This allows us to use an extremely simple throttling + * mechanism, and further to apply it only to the CPU doing floods of + * call_rcu() invocations. Don't try this at home! + */ +static void rcu_nocb_wait_contended(struct rcu_data *rdp) +{ + WARN_ON_ONCE(smp_processor_id() != rdp->cpu); + while (WARN_ON_ONCE(atomic_read(&rdp->nocb_lock_contended))) + cpu_relax(); +} + +/* + * Conditionally acquire the specified rcu_data structure's + * ->nocb_bypass_lock. + */ +static bool rcu_nocb_bypass_trylock(struct rcu_data *rdp) +{ + lockdep_assert_irqs_disabled(); + return raw_spin_trylock(&rdp->nocb_bypass_lock); +} + +/* + * Release the specified rcu_data structure's ->nocb_bypass_lock. + */ +static void rcu_nocb_bypass_unlock(struct rcu_data *rdp) + __releases(&rdp->nocb_bypass_lock) +{ + lockdep_assert_irqs_disabled(); + raw_spin_unlock(&rdp->nocb_bypass_lock); +} + +/* + * Acquire the specified rcu_data structure's ->nocb_lock, but only + * if it corresponds to a no-CBs CPU. + */ +static void rcu_nocb_lock(struct rcu_data *rdp) +{ + lockdep_assert_irqs_disabled(); + if (!rcu_rdp_is_offloaded(rdp)) + return; + raw_spin_lock(&rdp->nocb_lock); +} + +/* + * Release the specified rcu_data structure's ->nocb_lock, but only + * if it corresponds to a no-CBs CPU. + */ +static void rcu_nocb_unlock(struct rcu_data *rdp) +{ + if (rcu_rdp_is_offloaded(rdp)) { + lockdep_assert_irqs_disabled(); + raw_spin_unlock(&rdp->nocb_lock); + } +} + +/* + * Release the specified rcu_data structure's ->nocb_lock and restore + * interrupts, but only if it corresponds to a no-CBs CPU. + */ +static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp, + unsigned long flags) +{ + if (rcu_rdp_is_offloaded(rdp)) { + lockdep_assert_irqs_disabled(); + raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); + } else { + local_irq_restore(flags); + } +} + +/* Lockdep check that ->cblist may be safely accessed. */ +static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp) +{ + lockdep_assert_irqs_disabled(); + if (rcu_rdp_is_offloaded(rdp)) + lockdep_assert_held(&rdp->nocb_lock); +} + +/* + * Wake up any no-CBs CPUs' kthreads that were waiting on the just-ended + * grace period. + */ +static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq) +{ + swake_up_all(sq); +} + +static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp) +{ + return &rnp->nocb_gp_wq[rcu_seq_ctr(rnp->gp_seq) & 0x1]; +} + +static void rcu_init_one_nocb(struct rcu_node *rnp) +{ + init_swait_queue_head(&rnp->nocb_gp_wq[0]); + init_swait_queue_head(&rnp->nocb_gp_wq[1]); +} + +/* Is the specified CPU a no-CBs CPU? */ +bool rcu_is_nocb_cpu(int cpu) +{ + if (cpumask_available(rcu_nocb_mask)) + return cpumask_test_cpu(cpu, rcu_nocb_mask); + return false; +} + +static bool __wake_nocb_gp(struct rcu_data *rdp_gp, + struct rcu_data *rdp, + bool force, unsigned long flags) + __releases(rdp_gp->nocb_gp_lock) +{ + bool needwake = false; + + if (!READ_ONCE(rdp_gp->nocb_gp_kthread)) { + raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("AlreadyAwake")); + return false; + } + + if (rdp_gp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) { + WRITE_ONCE(rdp_gp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT); + del_timer(&rdp_gp->nocb_timer); + } + + if (force || READ_ONCE(rdp_gp->nocb_gp_sleep)) { + WRITE_ONCE(rdp_gp->nocb_gp_sleep, false); + needwake = true; + } + raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); + if (needwake) { + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DoWake")); + wake_up_process(rdp_gp->nocb_gp_kthread); + } + + return needwake; +} + +/* + * Kick the GP kthread for this NOCB group. + */ +static bool wake_nocb_gp(struct rcu_data *rdp, bool force) +{ + unsigned long flags; + struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; + + raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); + return __wake_nocb_gp(rdp_gp, rdp, force, flags); +} + +/* + * Arrange to wake the GP kthread for this NOCB group at some future + * time when it is safe to do so. + */ +static void wake_nocb_gp_defer(struct rcu_data *rdp, int waketype, + const char *reason) +{ + unsigned long flags; + struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; + + raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); + + /* + * Bypass wakeup overrides previous deferments. In case + * of callback storm, no need to wake up too early. + */ + if (waketype == RCU_NOCB_WAKE_BYPASS) { + mod_timer(&rdp_gp->nocb_timer, jiffies + 2); + WRITE_ONCE(rdp_gp->nocb_defer_wakeup, waketype); + } else { + if (rdp_gp->nocb_defer_wakeup < RCU_NOCB_WAKE) + mod_timer(&rdp_gp->nocb_timer, jiffies + 1); + if (rdp_gp->nocb_defer_wakeup < waketype) + WRITE_ONCE(rdp_gp->nocb_defer_wakeup, waketype); + } + + raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); + + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, reason); +} + +/* + * Flush the ->nocb_bypass queue into ->cblist, enqueuing rhp if non-NULL. + * However, if there is a callback to be enqueued and if ->nocb_bypass + * proves to be initially empty, just return false because the no-CB GP + * kthread may need to be awakened in this case. + * + * Note that this function always returns true if rhp is NULL. + */ +static bool rcu_nocb_do_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, + unsigned long j) +{ + struct rcu_cblist rcl; + + WARN_ON_ONCE(!rcu_rdp_is_offloaded(rdp)); + rcu_lockdep_assert_cblist_protected(rdp); + lockdep_assert_held(&rdp->nocb_bypass_lock); + if (rhp && !rcu_cblist_n_cbs(&rdp->nocb_bypass)) { + raw_spin_unlock(&rdp->nocb_bypass_lock); + return false; + } + /* Note: ->cblist.len already accounts for ->nocb_bypass contents. */ + if (rhp) + rcu_segcblist_inc_len(&rdp->cblist); /* Must precede enqueue. */ + rcu_cblist_flush_enqueue(&rcl, &rdp->nocb_bypass, rhp); + rcu_segcblist_insert_pend_cbs(&rdp->cblist, &rcl); + WRITE_ONCE(rdp->nocb_bypass_first, j); + rcu_nocb_bypass_unlock(rdp); + return true; +} + +/* + * Flush the ->nocb_bypass queue into ->cblist, enqueuing rhp if non-NULL. + * However, if there is a callback to be enqueued and if ->nocb_bypass + * proves to be initially empty, just return false because the no-CB GP + * kthread may need to be awakened in this case. + * + * Note that this function always returns true if rhp is NULL. + */ +static bool rcu_nocb_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, + unsigned long j) +{ + if (!rcu_rdp_is_offloaded(rdp)) + return true; + rcu_lockdep_assert_cblist_protected(rdp); + rcu_nocb_bypass_lock(rdp); + return rcu_nocb_do_flush_bypass(rdp, rhp, j); +} + +/* + * If the ->nocb_bypass_lock is immediately available, flush the + * ->nocb_bypass queue into ->cblist. + */ +static void rcu_nocb_try_flush_bypass(struct rcu_data *rdp, unsigned long j) +{ + rcu_lockdep_assert_cblist_protected(rdp); + if (!rcu_rdp_is_offloaded(rdp) || + !rcu_nocb_bypass_trylock(rdp)) + return; + WARN_ON_ONCE(!rcu_nocb_do_flush_bypass(rdp, NULL, j)); +} + +/* + * See whether it is appropriate to use the ->nocb_bypass list in order + * to control contention on ->nocb_lock. A limited number of direct + * enqueues are permitted into ->cblist per jiffy. If ->nocb_bypass + * is non-empty, further callbacks must be placed into ->nocb_bypass, + * otherwise rcu_barrier() breaks. Use rcu_nocb_flush_bypass() to switch + * back to direct use of ->cblist. However, ->nocb_bypass should not be + * used if ->cblist is empty, because otherwise callbacks can be stranded + * on ->nocb_bypass because we cannot count on the current CPU ever again + * invoking call_rcu(). The general rule is that if ->nocb_bypass is + * non-empty, the corresponding no-CBs grace-period kthread must not be + * in an indefinite sleep state. + * + * Finally, it is not permitted to use the bypass during early boot, + * as doing so would confuse the auto-initialization code. Besides + * which, there is no point in worrying about lock contention while + * there is only one CPU in operation. + */ +static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp, + bool *was_alldone, unsigned long flags) +{ + unsigned long c; + unsigned long cur_gp_seq; + unsigned long j = jiffies; + long ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); + + lockdep_assert_irqs_disabled(); + + // Pure softirq/rcuc based processing: no bypassing, no + // locking. + if (!rcu_rdp_is_offloaded(rdp)) { + *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); + return false; + } + + // In the process of (de-)offloading: no bypassing, but + // locking. + if (!rcu_segcblist_completely_offloaded(&rdp->cblist)) { + rcu_nocb_lock(rdp); + *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); + return false; /* Not offloaded, no bypassing. */ + } + + // Don't use ->nocb_bypass during early boot. + if (rcu_scheduler_active != RCU_SCHEDULER_RUNNING) { + rcu_nocb_lock(rdp); + WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); + *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); + return false; + } + + // If we have advanced to a new jiffy, reset counts to allow + // moving back from ->nocb_bypass to ->cblist. + if (j == rdp->nocb_nobypass_last) { + c = rdp->nocb_nobypass_count + 1; + } else { + WRITE_ONCE(rdp->nocb_nobypass_last, j); + c = rdp->nocb_nobypass_count - nocb_nobypass_lim_per_jiffy; + if (ULONG_CMP_LT(rdp->nocb_nobypass_count, + nocb_nobypass_lim_per_jiffy)) + c = 0; + else if (c > nocb_nobypass_lim_per_jiffy) + c = nocb_nobypass_lim_per_jiffy; + } + WRITE_ONCE(rdp->nocb_nobypass_count, c); + + // If there hasn't yet been all that many ->cblist enqueues + // this jiffy, tell the caller to enqueue onto ->cblist. But flush + // ->nocb_bypass first. + if (rdp->nocb_nobypass_count < nocb_nobypass_lim_per_jiffy) { + rcu_nocb_lock(rdp); + *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); + if (*was_alldone) + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("FirstQ")); + WARN_ON_ONCE(!rcu_nocb_flush_bypass(rdp, NULL, j)); + WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); + return false; // Caller must enqueue the callback. + } + + // If ->nocb_bypass has been used too long or is too full, + // flush ->nocb_bypass to ->cblist. + if ((ncbs && j != READ_ONCE(rdp->nocb_bypass_first)) || + ncbs >= qhimark) { + rcu_nocb_lock(rdp); + if (!rcu_nocb_flush_bypass(rdp, rhp, j)) { + *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); + if (*was_alldone) + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("FirstQ")); + WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); + return false; // Caller must enqueue the callback. + } + if (j != rdp->nocb_gp_adv_time && + rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq) && + rcu_seq_done(&rdp->mynode->gp_seq, cur_gp_seq)) { + rcu_advance_cbs_nowake(rdp->mynode, rdp); + rdp->nocb_gp_adv_time = j; + } + rcu_nocb_unlock_irqrestore(rdp, flags); + return true; // Callback already enqueued. + } + + // We need to use the bypass. + rcu_nocb_wait_contended(rdp); + rcu_nocb_bypass_lock(rdp); + ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); + rcu_segcblist_inc_len(&rdp->cblist); /* Must precede enqueue. */ + rcu_cblist_enqueue(&rdp->nocb_bypass, rhp); + if (!ncbs) { + WRITE_ONCE(rdp->nocb_bypass_first, j); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("FirstBQ")); + } + rcu_nocb_bypass_unlock(rdp); + smp_mb(); /* Order enqueue before wake. */ + if (ncbs) { + local_irq_restore(flags); + } else { + // No-CBs GP kthread might be indefinitely asleep, if so, wake. + rcu_nocb_lock(rdp); // Rare during call_rcu() flood. + if (!rcu_segcblist_pend_cbs(&rdp->cblist)) { + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("FirstBQwake")); + __call_rcu_nocb_wake(rdp, true, flags); + } else { + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("FirstBQnoWake")); + rcu_nocb_unlock_irqrestore(rdp, flags); + } + } + return true; // Callback already enqueued. +} + +/* + * Awaken the no-CBs grace-period kthread if needed, either due to it + * legitimately being asleep or due to overload conditions. + * + * If warranted, also wake up the kthread servicing this CPUs queues. + */ +static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone, + unsigned long flags) + __releases(rdp->nocb_lock) +{ + unsigned long cur_gp_seq; + unsigned long j; + long len; + struct task_struct *t; + + // If we are being polled or there is no kthread, just leave. + t = READ_ONCE(rdp->nocb_gp_kthread); + if (rcu_nocb_poll || !t) { + rcu_nocb_unlock_irqrestore(rdp, flags); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("WakeNotPoll")); + return; + } + // Need to actually to a wakeup. + len = rcu_segcblist_n_cbs(&rdp->cblist); + if (was_alldone) { + rdp->qlen_last_fqs_check = len; + if (!irqs_disabled_flags(flags)) { + /* ... if queue was empty ... */ + rcu_nocb_unlock_irqrestore(rdp, flags); + wake_nocb_gp(rdp, false); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("WakeEmpty")); + } else { + rcu_nocb_unlock_irqrestore(rdp, flags); + wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE, + TPS("WakeEmptyIsDeferred")); + } + } else if (len > rdp->qlen_last_fqs_check + qhimark) { + /* ... or if many callbacks queued. */ + rdp->qlen_last_fqs_check = len; + j = jiffies; + if (j != rdp->nocb_gp_adv_time && + rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq) && + rcu_seq_done(&rdp->mynode->gp_seq, cur_gp_seq)) { + rcu_advance_cbs_nowake(rdp->mynode, rdp); + rdp->nocb_gp_adv_time = j; + } + smp_mb(); /* Enqueue before timer_pending(). */ + if ((rdp->nocb_cb_sleep || + !rcu_segcblist_ready_cbs(&rdp->cblist)) && + !timer_pending(&rdp->nocb_timer)) { + rcu_nocb_unlock_irqrestore(rdp, flags); + wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE_FORCE, + TPS("WakeOvfIsDeferred")); + } else { + rcu_nocb_unlock_irqrestore(rdp, flags); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeNot")); + } + } else { + rcu_nocb_unlock_irqrestore(rdp, flags); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeNot")); + } + return; +} + +/* + * Check if we ignore this rdp. + * + * We check that without holding the nocb lock but + * we make sure not to miss a freshly offloaded rdp + * with the current ordering: + * + * rdp_offload_toggle() nocb_gp_enabled_cb() + * ------------------------- ---------------------------- + * WRITE flags LOCK nocb_gp_lock + * LOCK nocb_gp_lock READ/WRITE nocb_gp_sleep + * READ/WRITE nocb_gp_sleep UNLOCK nocb_gp_lock + * UNLOCK nocb_gp_lock READ flags + */ +static inline bool nocb_gp_enabled_cb(struct rcu_data *rdp) +{ + u8 flags = SEGCBLIST_OFFLOADED | SEGCBLIST_KTHREAD_GP; + + return rcu_segcblist_test_flags(&rdp->cblist, flags); +} + +static inline bool nocb_gp_update_state_deoffloading(struct rcu_data *rdp, + bool *needwake_state) +{ + struct rcu_segcblist *cblist = &rdp->cblist; + + if (rcu_segcblist_test_flags(cblist, SEGCBLIST_OFFLOADED)) { + if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)) { + rcu_segcblist_set_flags(cblist, SEGCBLIST_KTHREAD_GP); + if (rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)) + *needwake_state = true; + } + return false; + } + + /* + * De-offloading. Clear our flag and notify the de-offload worker. + * We will ignore this rdp until it ever gets re-offloaded. + */ + WARN_ON_ONCE(!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)); + rcu_segcblist_clear_flags(cblist, SEGCBLIST_KTHREAD_GP); + if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)) + *needwake_state = true; + return true; +} + + +/* + * No-CBs GP kthreads come here to wait for additional callbacks to show up + * or for grace periods to end. + */ +static void nocb_gp_wait(struct rcu_data *my_rdp) +{ + bool bypass = false; + long bypass_ncbs; + int __maybe_unused cpu = my_rdp->cpu; + unsigned long cur_gp_seq; + unsigned long flags; + bool gotcbs = false; + unsigned long j = jiffies; + bool needwait_gp = false; // This prevents actual uninitialized use. + bool needwake; + bool needwake_gp; + struct rcu_data *rdp; + struct rcu_node *rnp; + unsigned long wait_gp_seq = 0; // Suppress "use uninitialized" warning. + bool wasempty = false; + + /* + * Each pass through the following loop checks for CBs and for the + * nearest grace period (if any) to wait for next. The CB kthreads + * and the global grace-period kthread are awakened if needed. + */ + WARN_ON_ONCE(my_rdp->nocb_gp_rdp != my_rdp); + for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_cb_rdp) { + bool needwake_state = false; + + if (!nocb_gp_enabled_cb(rdp)) + continue; + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Check")); + rcu_nocb_lock_irqsave(rdp, flags); + if (nocb_gp_update_state_deoffloading(rdp, &needwake_state)) { + rcu_nocb_unlock_irqrestore(rdp, flags); + if (needwake_state) + swake_up_one(&rdp->nocb_state_wq); + continue; + } + bypass_ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); + if (bypass_ncbs && + (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + 1) || + bypass_ncbs > 2 * qhimark)) { + // Bypass full or old, so flush it. + (void)rcu_nocb_try_flush_bypass(rdp, j); + bypass_ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); + } else if (!bypass_ncbs && rcu_segcblist_empty(&rdp->cblist)) { + rcu_nocb_unlock_irqrestore(rdp, flags); + if (needwake_state) + swake_up_one(&rdp->nocb_state_wq); + continue; /* No callbacks here, try next. */ + } + if (bypass_ncbs) { + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("Bypass")); + bypass = true; + } + rnp = rdp->mynode; + + // Advance callbacks if helpful and low contention. + needwake_gp = false; + if (!rcu_segcblist_restempty(&rdp->cblist, + RCU_NEXT_READY_TAIL) || + (rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq) && + rcu_seq_done(&rnp->gp_seq, cur_gp_seq))) { + raw_spin_lock_rcu_node(rnp); /* irqs disabled. */ + needwake_gp = rcu_advance_cbs(rnp, rdp); + wasempty = rcu_segcblist_restempty(&rdp->cblist, + RCU_NEXT_READY_TAIL); + raw_spin_unlock_rcu_node(rnp); /* irqs disabled. */ + } + // Need to wait on some grace period? + WARN_ON_ONCE(wasempty && + !rcu_segcblist_restempty(&rdp->cblist, + RCU_NEXT_READY_TAIL)); + if (rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq)) { + if (!needwait_gp || + ULONG_CMP_LT(cur_gp_seq, wait_gp_seq)) + wait_gp_seq = cur_gp_seq; + needwait_gp = true; + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, + TPS("NeedWaitGP")); + } + if (rcu_segcblist_ready_cbs(&rdp->cblist)) { + needwake = rdp->nocb_cb_sleep; + WRITE_ONCE(rdp->nocb_cb_sleep, false); + smp_mb(); /* CB invocation -after- GP end. */ + } else { + needwake = false; + } + rcu_nocb_unlock_irqrestore(rdp, flags); + if (needwake) { + swake_up_one(&rdp->nocb_cb_wq); + gotcbs = true; + } + if (needwake_gp) + rcu_gp_kthread_wake(); + if (needwake_state) + swake_up_one(&rdp->nocb_state_wq); + } + + my_rdp->nocb_gp_bypass = bypass; + my_rdp->nocb_gp_gp = needwait_gp; + my_rdp->nocb_gp_seq = needwait_gp ? wait_gp_seq : 0; + + if (bypass && !rcu_nocb_poll) { + // At least one child with non-empty ->nocb_bypass, so set + // timer in order to avoid stranding its callbacks. + wake_nocb_gp_defer(my_rdp, RCU_NOCB_WAKE_BYPASS, + TPS("WakeBypassIsDeferred")); + } + if (rcu_nocb_poll) { + /* Polling, so trace if first poll in the series. */ + if (gotcbs) + trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Poll")); + schedule_timeout_idle(1); + } else if (!needwait_gp) { + /* Wait for callbacks to appear. */ + trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Sleep")); + swait_event_interruptible_exclusive(my_rdp->nocb_gp_wq, + !READ_ONCE(my_rdp->nocb_gp_sleep)); + trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("EndSleep")); + } else { + rnp = my_rdp->mynode; + trace_rcu_this_gp(rnp, my_rdp, wait_gp_seq, TPS("StartWait")); + swait_event_interruptible_exclusive( + rnp->nocb_gp_wq[rcu_seq_ctr(wait_gp_seq) & 0x1], + rcu_seq_done(&rnp->gp_seq, wait_gp_seq) || + !READ_ONCE(my_rdp->nocb_gp_sleep)); + trace_rcu_this_gp(rnp, my_rdp, wait_gp_seq, TPS("EndWait")); + } + if (!rcu_nocb_poll) { + raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags); + if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) { + WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT); + del_timer(&my_rdp->nocb_timer); + } + WRITE_ONCE(my_rdp->nocb_gp_sleep, true); + raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags); + } + my_rdp->nocb_gp_seq = -1; + WARN_ON(signal_pending(current)); +} + +/* + * No-CBs grace-period-wait kthread. There is one of these per group + * of CPUs, but only once at least one CPU in that group has come online + * at least once since boot. This kthread checks for newly posted + * callbacks from any of the CPUs it is responsible for, waits for a + * grace period, then awakens all of the rcu_nocb_cb_kthread() instances + * that then have callback-invocation work to do. + */ +static int rcu_nocb_gp_kthread(void *arg) +{ + struct rcu_data *rdp = arg; + + for (;;) { + WRITE_ONCE(rdp->nocb_gp_loops, rdp->nocb_gp_loops + 1); + nocb_gp_wait(rdp); + cond_resched_tasks_rcu_qs(); + } + return 0; +} + +static inline bool nocb_cb_can_run(struct rcu_data *rdp) +{ + u8 flags = SEGCBLIST_OFFLOADED | SEGCBLIST_KTHREAD_CB; + return rcu_segcblist_test_flags(&rdp->cblist, flags); +} + +static inline bool nocb_cb_wait_cond(struct rcu_data *rdp) +{ + return nocb_cb_can_run(rdp) && !READ_ONCE(rdp->nocb_cb_sleep); +} + +/* + * Invoke any ready callbacks from the corresponding no-CBs CPU, + * then, if there are no more, wait for more to appear. + */ +static void nocb_cb_wait(struct rcu_data *rdp) +{ + struct rcu_segcblist *cblist = &rdp->cblist; + unsigned long cur_gp_seq; + unsigned long flags; + bool needwake_state = false; + bool needwake_gp = false; + bool can_sleep = true; + struct rcu_node *rnp = rdp->mynode; + + local_irq_save(flags); + rcu_momentary_dyntick_idle(); + local_irq_restore(flags); + /* + * Disable BH to provide the expected environment. Also, when + * transitioning to/from NOCB mode, a self-requeuing callback might + * be invoked from softirq. A short grace period could cause both + * instances of this callback would execute concurrently. + */ + local_bh_disable(); + rcu_do_batch(rdp); + local_bh_enable(); + lockdep_assert_irqs_enabled(); + rcu_nocb_lock_irqsave(rdp, flags); + if (rcu_segcblist_nextgp(cblist, &cur_gp_seq) && + rcu_seq_done(&rnp->gp_seq, cur_gp_seq) && + raw_spin_trylock_rcu_node(rnp)) { /* irqs already disabled. */ + needwake_gp = rcu_advance_cbs(rdp->mynode, rdp); + raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */ + } + + if (rcu_segcblist_test_flags(cblist, SEGCBLIST_OFFLOADED)) { + if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)) { + rcu_segcblist_set_flags(cblist, SEGCBLIST_KTHREAD_CB); + if (rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)) + needwake_state = true; + } + if (rcu_segcblist_ready_cbs(cblist)) + can_sleep = false; + } else { + /* + * De-offloading. Clear our flag and notify the de-offload worker. + * We won't touch the callbacks and keep sleeping until we ever + * get re-offloaded. + */ + WARN_ON_ONCE(!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)); + rcu_segcblist_clear_flags(cblist, SEGCBLIST_KTHREAD_CB); + if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)) + needwake_state = true; + } + + WRITE_ONCE(rdp->nocb_cb_sleep, can_sleep); + + if (rdp->nocb_cb_sleep) + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("CBSleep")); + + rcu_nocb_unlock_irqrestore(rdp, flags); + if (needwake_gp) + rcu_gp_kthread_wake(); + + if (needwake_state) + swake_up_one(&rdp->nocb_state_wq); + + do { + swait_event_interruptible_exclusive(rdp->nocb_cb_wq, + nocb_cb_wait_cond(rdp)); + + // VVV Ensure CB invocation follows _sleep test. + if (smp_load_acquire(&rdp->nocb_cb_sleep)) { // ^^^ + WARN_ON(signal_pending(current)); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WokeEmpty")); + } + } while (!nocb_cb_can_run(rdp)); +} + +/* + * Per-rcu_data kthread, but only for no-CBs CPUs. Repeatedly invoke + * nocb_cb_wait() to do the dirty work. + */ +static int rcu_nocb_cb_kthread(void *arg) +{ + struct rcu_data *rdp = arg; + + // Each pass through this loop does one callback batch, and, + // if there are no more ready callbacks, waits for them. + for (;;) { + nocb_cb_wait(rdp); + cond_resched_tasks_rcu_qs(); + } + return 0; +} + +/* Is a deferred wakeup of rcu_nocb_kthread() required? */ +static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp, int level) +{ + return READ_ONCE(rdp->nocb_defer_wakeup) >= level; +} + +/* Do a deferred wakeup of rcu_nocb_kthread(). */ +static bool do_nocb_deferred_wakeup_common(struct rcu_data *rdp_gp, + struct rcu_data *rdp, int level, + unsigned long flags) + __releases(rdp_gp->nocb_gp_lock) +{ + int ndw; + int ret; + + if (!rcu_nocb_need_deferred_wakeup(rdp_gp, level)) { + raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); + return false; + } + + ndw = rdp_gp->nocb_defer_wakeup; + ret = __wake_nocb_gp(rdp_gp, rdp, ndw == RCU_NOCB_WAKE_FORCE, flags); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DeferredWake")); + + return ret; +} + +/* Do a deferred wakeup of rcu_nocb_kthread() from a timer handler. */ +static void do_nocb_deferred_wakeup_timer(struct timer_list *t) +{ + unsigned long flags; + struct rcu_data *rdp = from_timer(rdp, t, nocb_timer); + + WARN_ON_ONCE(rdp->nocb_gp_rdp != rdp); + trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Timer")); + + raw_spin_lock_irqsave(&rdp->nocb_gp_lock, flags); + smp_mb__after_spinlock(); /* Timer expire before wakeup. */ + do_nocb_deferred_wakeup_common(rdp, rdp, RCU_NOCB_WAKE_BYPASS, flags); +} + +/* + * Do a deferred wakeup of rcu_nocb_kthread() from fastpath. + * This means we do an inexact common-case check. Note that if + * we miss, ->nocb_timer will eventually clean things up. + */ +static bool do_nocb_deferred_wakeup(struct rcu_data *rdp) +{ + unsigned long flags; + struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; + + if (!rdp_gp || !rcu_nocb_need_deferred_wakeup(rdp_gp, RCU_NOCB_WAKE)) + return false; + + raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); + return do_nocb_deferred_wakeup_common(rdp_gp, rdp, RCU_NOCB_WAKE, flags); +} + +void rcu_nocb_flush_deferred_wakeup(void) +{ + do_nocb_deferred_wakeup(this_cpu_ptr(&rcu_data)); +} +EXPORT_SYMBOL_GPL(rcu_nocb_flush_deferred_wakeup); + +static int rdp_offload_toggle(struct rcu_data *rdp, + bool offload, unsigned long flags) + __releases(rdp->nocb_lock) +{ + struct rcu_segcblist *cblist = &rdp->cblist; + struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; + bool wake_gp = false; + + rcu_segcblist_offload(cblist, offload); + + if (rdp->nocb_cb_sleep) + rdp->nocb_cb_sleep = false; + rcu_nocb_unlock_irqrestore(rdp, flags); + + /* + * Ignore former value of nocb_cb_sleep and force wake up as it could + * have been spuriously set to false already. + */ + swake_up_one(&rdp->nocb_cb_wq); + + raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); + if (rdp_gp->nocb_gp_sleep) { + rdp_gp->nocb_gp_sleep = false; + wake_gp = true; + } + raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); + + if (wake_gp) + wake_up_process(rdp_gp->nocb_gp_kthread); + + return 0; +} + +static long rcu_nocb_rdp_deoffload(void *arg) +{ + struct rcu_data *rdp = arg; + struct rcu_segcblist *cblist = &rdp->cblist; + unsigned long flags; + int ret; + + WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); + + pr_info("De-offloading %d\n", rdp->cpu); + + rcu_nocb_lock_irqsave(rdp, flags); + /* + * Flush once and for all now. This suffices because we are + * running on the target CPU holding ->nocb_lock (thus having + * interrupts disabled), and because rdp_offload_toggle() + * invokes rcu_segcblist_offload(), which clears SEGCBLIST_OFFLOADED. + * Thus future calls to rcu_segcblist_completely_offloaded() will + * return false, which means that future calls to rcu_nocb_try_bypass() + * will refuse to put anything into the bypass. + */ + WARN_ON_ONCE(!rcu_nocb_flush_bypass(rdp, NULL, jiffies)); + ret = rdp_offload_toggle(rdp, false, flags); + swait_event_exclusive(rdp->nocb_state_wq, + !rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB | + SEGCBLIST_KTHREAD_GP)); + /* + * Lock one last time to acquire latest callback updates from kthreads + * so we can later handle callbacks locally without locking. + */ + rcu_nocb_lock_irqsave(rdp, flags); + /* + * Theoretically we could set SEGCBLIST_SOFTIRQ_ONLY after the nocb + * lock is released but how about being paranoid for once? + */ + rcu_segcblist_set_flags(cblist, SEGCBLIST_SOFTIRQ_ONLY); + /* + * With SEGCBLIST_SOFTIRQ_ONLY, we can't use + * rcu_nocb_unlock_irqrestore() anymore. + */ + raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); + + /* Sanity check */ + WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); + + + return ret; +} + +int rcu_nocb_cpu_deoffload(int cpu) +{ + struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); + int ret = 0; + + mutex_lock(&rcu_state.barrier_mutex); + cpus_read_lock(); + if (rcu_rdp_is_offloaded(rdp)) { + if (cpu_online(cpu)) { + ret = work_on_cpu(cpu, rcu_nocb_rdp_deoffload, rdp); + if (!ret) + cpumask_clear_cpu(cpu, rcu_nocb_mask); + } else { + pr_info("NOCB: Can't CB-deoffload an offline CPU\n"); + ret = -EINVAL; + } + } + cpus_read_unlock(); + mutex_unlock(&rcu_state.barrier_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(rcu_nocb_cpu_deoffload); + +static long rcu_nocb_rdp_offload(void *arg) +{ + struct rcu_data *rdp = arg; + struct rcu_segcblist *cblist = &rdp->cblist; + unsigned long flags; + int ret; + + WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); + /* + * For now we only support re-offload, ie: the rdp must have been + * offloaded on boot first. + */ + if (!rdp->nocb_gp_rdp) + return -EINVAL; + + pr_info("Offloading %d\n", rdp->cpu); + /* + * Can't use rcu_nocb_lock_irqsave() while we are in + * SEGCBLIST_SOFTIRQ_ONLY mode. + */ + raw_spin_lock_irqsave(&rdp->nocb_lock, flags); + + /* + * We didn't take the nocb lock while working on the + * rdp->cblist in SEGCBLIST_SOFTIRQ_ONLY mode. + * Every modifications that have been done previously on + * rdp->cblist must be visible remotely by the nocb kthreads + * upon wake up after reading the cblist flags. + * + * The layout against nocb_lock enforces that ordering: + * + * __rcu_nocb_rdp_offload() nocb_cb_wait()/nocb_gp_wait() + * ------------------------- ---------------------------- + * WRITE callbacks rcu_nocb_lock() + * rcu_nocb_lock() READ flags + * WRITE flags READ callbacks + * rcu_nocb_unlock() rcu_nocb_unlock() + */ + ret = rdp_offload_toggle(rdp, true, flags); + swait_event_exclusive(rdp->nocb_state_wq, + rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB) && + rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)); + + return ret; +} + +int rcu_nocb_cpu_offload(int cpu) +{ + struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); + int ret = 0; + + mutex_lock(&rcu_state.barrier_mutex); + cpus_read_lock(); + if (!rcu_rdp_is_offloaded(rdp)) { + if (cpu_online(cpu)) { + ret = work_on_cpu(cpu, rcu_nocb_rdp_offload, rdp); + if (!ret) + cpumask_set_cpu(cpu, rcu_nocb_mask); + } else { + pr_info("NOCB: Can't CB-offload an offline CPU\n"); + ret = -EINVAL; + } + } + cpus_read_unlock(); + mutex_unlock(&rcu_state.barrier_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(rcu_nocb_cpu_offload); + +void __init rcu_init_nohz(void) +{ + int cpu; + bool need_rcu_nocb_mask = false; + struct rcu_data *rdp; + +#if defined(CONFIG_NO_HZ_FULL) + if (tick_nohz_full_running && cpumask_weight(tick_nohz_full_mask)) + need_rcu_nocb_mask = true; +#endif /* #if defined(CONFIG_NO_HZ_FULL) */ + + if (!cpumask_available(rcu_nocb_mask) && need_rcu_nocb_mask) { + if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { + pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); + return; + } + } + if (!cpumask_available(rcu_nocb_mask)) + return; + +#if defined(CONFIG_NO_HZ_FULL) + if (tick_nohz_full_running) + cpumask_or(rcu_nocb_mask, rcu_nocb_mask, tick_nohz_full_mask); +#endif /* #if defined(CONFIG_NO_HZ_FULL) */ + + if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { + pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n"); + cpumask_and(rcu_nocb_mask, cpu_possible_mask, + rcu_nocb_mask); + } + if (cpumask_empty(rcu_nocb_mask)) + pr_info("\tOffload RCU callbacks from CPUs: (none).\n"); + else + pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n", + cpumask_pr_args(rcu_nocb_mask)); + if (rcu_nocb_poll) + pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); + + for_each_cpu(cpu, rcu_nocb_mask) { + rdp = per_cpu_ptr(&rcu_data, cpu); + if (rcu_segcblist_empty(&rdp->cblist)) + rcu_segcblist_init(&rdp->cblist); + rcu_segcblist_offload(&rdp->cblist, true); + rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB); + rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_GP); + } + rcu_organize_nocb_kthreads(); +} + +/* Initialize per-rcu_data variables for no-CBs CPUs. */ +static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) +{ + init_swait_queue_head(&rdp->nocb_cb_wq); + init_swait_queue_head(&rdp->nocb_gp_wq); + init_swait_queue_head(&rdp->nocb_state_wq); + raw_spin_lock_init(&rdp->nocb_lock); + raw_spin_lock_init(&rdp->nocb_bypass_lock); + raw_spin_lock_init(&rdp->nocb_gp_lock); + timer_setup(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer, 0); + rcu_cblist_init(&rdp->nocb_bypass); +} + +/* + * If the specified CPU is a no-CBs CPU that does not already have its + * rcuo CB kthread, spawn it. Additionally, if the rcuo GP kthread + * for this CPU's group has not yet been created, spawn it as well. + */ +static void rcu_spawn_one_nocb_kthread(int cpu) +{ + struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); + struct rcu_data *rdp_gp; + struct task_struct *t; + + /* + * If this isn't a no-CBs CPU or if it already has an rcuo kthread, + * then nothing to do. + */ + if (!rcu_is_nocb_cpu(cpu) || rdp->nocb_cb_kthread) + return; + + /* If we didn't spawn the GP kthread first, reorganize! */ + rdp_gp = rdp->nocb_gp_rdp; + if (!rdp_gp->nocb_gp_kthread) { + t = kthread_run(rcu_nocb_gp_kthread, rdp_gp, + "rcuog/%d", rdp_gp->cpu); + if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo GP kthread, OOM is now expected behavior\n", __func__)) + return; + WRITE_ONCE(rdp_gp->nocb_gp_kthread, t); + } + + /* Spawn the kthread for this CPU. */ + t = kthread_run(rcu_nocb_cb_kthread, rdp, + "rcuo%c/%d", rcu_state.abbr, cpu); + if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo CB kthread, OOM is now expected behavior\n", __func__)) + return; + WRITE_ONCE(rdp->nocb_cb_kthread, t); + WRITE_ONCE(rdp->nocb_gp_kthread, rdp_gp->nocb_gp_kthread); +} + +/* + * If the specified CPU is a no-CBs CPU that does not already have its + * rcuo kthread, spawn it. + */ +static void rcu_spawn_cpu_nocb_kthread(int cpu) +{ + if (rcu_scheduler_fully_active) + rcu_spawn_one_nocb_kthread(cpu); +} + +/* + * Once the scheduler is running, spawn rcuo kthreads for all online + * no-CBs CPUs. This assumes that the early_initcall()s happen before + * non-boot CPUs come online -- if this changes, we will need to add + * some mutual exclusion. + */ +static void __init rcu_spawn_nocb_kthreads(void) +{ + int cpu; + + for_each_online_cpu(cpu) + rcu_spawn_cpu_nocb_kthread(cpu); +} + +/* How many CB CPU IDs per GP kthread? Default of -1 for sqrt(nr_cpu_ids). */ +static int rcu_nocb_gp_stride = -1; +module_param(rcu_nocb_gp_stride, int, 0444); + +/* + * Initialize GP-CB relationships for all no-CBs CPU. + */ +static void __init rcu_organize_nocb_kthreads(void) +{ + int cpu; + bool firsttime = true; + bool gotnocbs = false; + bool gotnocbscbs = true; + int ls = rcu_nocb_gp_stride; + int nl = 0; /* Next GP kthread. */ + struct rcu_data *rdp; + struct rcu_data *rdp_gp = NULL; /* Suppress misguided gcc warn. */ + struct rcu_data *rdp_prev = NULL; + + if (!cpumask_available(rcu_nocb_mask)) + return; + if (ls == -1) { + ls = nr_cpu_ids / int_sqrt(nr_cpu_ids); + rcu_nocb_gp_stride = ls; + } + + /* + * Each pass through this loop sets up one rcu_data structure. + * Should the corresponding CPU come online in the future, then + * we will spawn the needed set of rcu_nocb_kthread() kthreads. + */ + for_each_cpu(cpu, rcu_nocb_mask) { + rdp = per_cpu_ptr(&rcu_data, cpu); + if (rdp->cpu >= nl) { + /* New GP kthread, set up for CBs & next GP. */ + gotnocbs = true; + nl = DIV_ROUND_UP(rdp->cpu + 1, ls) * ls; + rdp->nocb_gp_rdp = rdp; + rdp_gp = rdp; + if (dump_tree) { + if (!firsttime) + pr_cont("%s\n", gotnocbscbs + ? "" : " (self only)"); + gotnocbscbs = false; + firsttime = false; + pr_alert("%s: No-CB GP kthread CPU %d:", + __func__, cpu); + } + } else { + /* Another CB kthread, link to previous GP kthread. */ + gotnocbscbs = true; + rdp->nocb_gp_rdp = rdp_gp; + rdp_prev->nocb_next_cb_rdp = rdp; + if (dump_tree) + pr_cont(" %d", cpu); + } + rdp_prev = rdp; + } + if (gotnocbs && dump_tree) + pr_cont("%s\n", gotnocbscbs ? "" : " (self only)"); +} + +/* + * Bind the current task to the offloaded CPUs. If there are no offloaded + * CPUs, leave the task unbound. Splat if the bind attempt fails. + */ +void rcu_bind_current_to_nocb(void) +{ + if (cpumask_available(rcu_nocb_mask) && cpumask_weight(rcu_nocb_mask)) + WARN_ON(sched_setaffinity(current->pid, rcu_nocb_mask)); +} +EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb); + +// The ->on_cpu field is available only in CONFIG_SMP=y, so... +#ifdef CONFIG_SMP +static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) +{ + return tsp && task_is_running(tsp) && !tsp->on_cpu ? "!" : ""; +} +#else // #ifdef CONFIG_SMP +static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) +{ + return ""; +} +#endif // #else #ifdef CONFIG_SMP + +/* + * Dump out nocb grace-period kthread state for the specified rcu_data + * structure. + */ +static void show_rcu_nocb_gp_state(struct rcu_data *rdp) +{ + struct rcu_node *rnp = rdp->mynode; + + pr_info("nocb GP %d %c%c%c%c%c %c[%c%c] %c%c:%ld rnp %d:%d %lu %c CPU %d%s\n", + rdp->cpu, + "kK"[!!rdp->nocb_gp_kthread], + "lL"[raw_spin_is_locked(&rdp->nocb_gp_lock)], + "dD"[!!rdp->nocb_defer_wakeup], + "tT"[timer_pending(&rdp->nocb_timer)], + "sS"[!!rdp->nocb_gp_sleep], + ".W"[swait_active(&rdp->nocb_gp_wq)], + ".W"[swait_active(&rnp->nocb_gp_wq[0])], + ".W"[swait_active(&rnp->nocb_gp_wq[1])], + ".B"[!!rdp->nocb_gp_bypass], + ".G"[!!rdp->nocb_gp_gp], + (long)rdp->nocb_gp_seq, + rnp->grplo, rnp->grphi, READ_ONCE(rdp->nocb_gp_loops), + rdp->nocb_gp_kthread ? task_state_to_char(rdp->nocb_gp_kthread) : '.', + rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1, + show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread)); +} + +/* Dump out nocb kthread state for the specified rcu_data structure. */ +static void show_rcu_nocb_state(struct rcu_data *rdp) +{ + char bufw[20]; + char bufr[20]; + struct rcu_segcblist *rsclp = &rdp->cblist; + bool waslocked; + bool wassleep; + + if (rdp->nocb_gp_rdp == rdp) + show_rcu_nocb_gp_state(rdp); + + sprintf(bufw, "%ld", rsclp->gp_seq[RCU_WAIT_TAIL]); + sprintf(bufr, "%ld", rsclp->gp_seq[RCU_NEXT_READY_TAIL]); + pr_info(" CB %d^%d->%d %c%c%c%c%c%c F%ld L%ld C%d %c%c%s%c%s%c%c q%ld %c CPU %d%s\n", + rdp->cpu, rdp->nocb_gp_rdp->cpu, + rdp->nocb_next_cb_rdp ? rdp->nocb_next_cb_rdp->cpu : -1, + "kK"[!!rdp->nocb_cb_kthread], + "bB"[raw_spin_is_locked(&rdp->nocb_bypass_lock)], + "cC"[!!atomic_read(&rdp->nocb_lock_contended)], + "lL"[raw_spin_is_locked(&rdp->nocb_lock)], + "sS"[!!rdp->nocb_cb_sleep], + ".W"[swait_active(&rdp->nocb_cb_wq)], + jiffies - rdp->nocb_bypass_first, + jiffies - rdp->nocb_nobypass_last, + rdp->nocb_nobypass_count, + ".D"[rcu_segcblist_ready_cbs(rsclp)], + ".W"[!rcu_segcblist_segempty(rsclp, RCU_WAIT_TAIL)], + rcu_segcblist_segempty(rsclp, RCU_WAIT_TAIL) ? "" : bufw, + ".R"[!rcu_segcblist_segempty(rsclp, RCU_NEXT_READY_TAIL)], + rcu_segcblist_segempty(rsclp, RCU_NEXT_READY_TAIL) ? "" : bufr, + ".N"[!rcu_segcblist_segempty(rsclp, RCU_NEXT_TAIL)], + ".B"[!!rcu_cblist_n_cbs(&rdp->nocb_bypass)], + rcu_segcblist_n_cbs(&rdp->cblist), + rdp->nocb_cb_kthread ? task_state_to_char(rdp->nocb_cb_kthread) : '.', + rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1, + show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread)); + + /* It is OK for GP kthreads to have GP state. */ + if (rdp->nocb_gp_rdp == rdp) + return; + + waslocked = raw_spin_is_locked(&rdp->nocb_gp_lock); + wassleep = swait_active(&rdp->nocb_gp_wq); + if (!rdp->nocb_gp_sleep && !waslocked && !wassleep) + return; /* Nothing untoward. */ + + pr_info(" nocb GP activity on CB-only CPU!!! %c%c%c %c\n", + "lL"[waslocked], + "dD"[!!rdp->nocb_defer_wakeup], + "sS"[!!rdp->nocb_gp_sleep], + ".W"[wassleep]); +} + +#else /* #ifdef CONFIG_RCU_NOCB_CPU */ + +static inline int rcu_lockdep_is_held_nocb(struct rcu_data *rdp) +{ + return 0; +} + +static inline bool rcu_current_is_nocb_kthread(struct rcu_data *rdp) +{ + return false; +} + +/* No ->nocb_lock to acquire. */ +static void rcu_nocb_lock(struct rcu_data *rdp) +{ +} + +/* No ->nocb_lock to release. */ +static void rcu_nocb_unlock(struct rcu_data *rdp) +{ +} + +/* No ->nocb_lock to release. */ +static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp, + unsigned long flags) +{ + local_irq_restore(flags); +} + +/* Lockdep check that ->cblist may be safely accessed. */ +static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp) +{ + lockdep_assert_irqs_disabled(); +} + +static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq) +{ +} + +static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp) +{ + return NULL; +} + +static void rcu_init_one_nocb(struct rcu_node *rnp) +{ +} + +static bool rcu_nocb_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, + unsigned long j) +{ + return true; +} + +static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp, + bool *was_alldone, unsigned long flags) +{ + return false; +} + +static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_empty, + unsigned long flags) +{ + WARN_ON_ONCE(1); /* Should be dead code! */ +} + +static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) +{ +} + +static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp, int level) +{ + return false; +} + +static bool do_nocb_deferred_wakeup(struct rcu_data *rdp) +{ + return false; +} + +static void rcu_spawn_cpu_nocb_kthread(int cpu) +{ +} + +static void __init rcu_spawn_nocb_kthreads(void) +{ +} + +static void show_rcu_nocb_state(struct rcu_data *rdp) +{ +} + +#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index de1dc3bb7f70..d070059163d7 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -13,39 +13,6 @@ #include "../locking/rtmutex_common.h" -#ifdef CONFIG_RCU_NOCB_CPU -static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks offloaded. */ -static bool __read_mostly rcu_nocb_poll; /* Offload kthread are to poll. */ -static inline int rcu_lockdep_is_held_nocb(struct rcu_data *rdp) -{ - return lockdep_is_held(&rdp->nocb_lock); -} - -static inline bool rcu_current_is_nocb_kthread(struct rcu_data *rdp) -{ - /* Race on early boot between thread creation and assignment */ - if (!rdp->nocb_cb_kthread || !rdp->nocb_gp_kthread) - return true; - - if (current == rdp->nocb_cb_kthread || current == rdp->nocb_gp_kthread) - if (in_task()) - return true; - return false; -} - -#else -static inline int rcu_lockdep_is_held_nocb(struct rcu_data *rdp) -{ - return 0; -} - -static inline bool rcu_current_is_nocb_kthread(struct rcu_data *rdp) -{ - return false; -} - -#endif /* #ifdef CONFIG_RCU_NOCB_CPU */ - static bool rcu_rdp_is_offloaded(struct rcu_data *rdp) { /* @@ -346,7 +313,7 @@ void rcu_note_context_switch(bool preempt) trace_rcu_utilization(TPS("Start context switch")); lockdep_assert_irqs_disabled(); - WARN_ON_ONCE(!preempt && rcu_preempt_depth() > 0); + WARN_ONCE(!preempt && rcu_preempt_depth() > 0, "Voluntary context switch within RCU read-side critical section!"); if (rcu_preempt_depth() > 0 && !t->rcu_read_unlock_special.b.blocked) { @@ -405,17 +372,20 @@ static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp) static void rcu_preempt_read_enter(void) { - current->rcu_read_lock_nesting++; + WRITE_ONCE(current->rcu_read_lock_nesting, READ_ONCE(current->rcu_read_lock_nesting) + 1); } static int rcu_preempt_read_exit(void) { - return --current->rcu_read_lock_nesting; + int ret = READ_ONCE(current->rcu_read_lock_nesting) - 1; + + WRITE_ONCE(current->rcu_read_lock_nesting, ret); + return ret; } static void rcu_preempt_depth_set(int val) { - current->rcu_read_lock_nesting = val; + WRITE_ONCE(current->rcu_read_lock_nesting, val); } /* @@ -559,7 +529,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) WRITE_ONCE(rnp->exp_tasks, np); if (IS_ENABLED(CONFIG_RCU_BOOST)) { /* Snapshot ->boost_mtx ownership w/rnp->lock held. */ - drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t; + drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx.rtmutex) == t; if (&t->rcu_node_entry == rnp->boost_tasks) WRITE_ONCE(rnp->boost_tasks, np); } @@ -586,7 +556,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) /* Unboost if we were boosted. */ if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex) - rt_mutex_futex_unlock(&rnp->boost_mtx); + rt_mutex_futex_unlock(&rnp->boost_mtx.rtmutex); /* * If this was the last task on the expedited lists, @@ -1083,7 +1053,7 @@ static int rcu_boost(struct rcu_node *rnp) * section. */ t = container_of(tb, struct task_struct, rcu_node_entry); - rt_mutex_init_proxy_locked(&rnp->boost_mtx, t); + rt_mutex_init_proxy_locked(&rnp->boost_mtx.rtmutex, t); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); /* Lock only for side effect: boosts task t's priority. */ rt_mutex_lock(&rnp->boost_mtx); @@ -1479,1460 +1449,6 @@ static void rcu_cleanup_after_idle(void) #endif /* #else #if !defined(CONFIG_RCU_FAST_NO_HZ) */ -#ifdef CONFIG_RCU_NOCB_CPU - -/* - * Offload callback processing from the boot-time-specified set of CPUs - * specified by rcu_nocb_mask. For the CPUs in the set, there are kthreads - * created that pull the callbacks from the corresponding CPU, wait for - * a grace period to elapse, and invoke the callbacks. These kthreads - * are organized into GP kthreads, which manage incoming callbacks, wait for - * grace periods, and awaken CB kthreads, and the CB kthreads, which only - * invoke callbacks. Each GP kthread invokes its own CBs. The no-CBs CPUs - * do a wake_up() on their GP kthread when they insert a callback into any - * empty list, unless the rcu_nocb_poll boot parameter has been specified, - * in which case each kthread actively polls its CPU. (Which isn't so great - * for energy efficiency, but which does reduce RCU's overhead on that CPU.) - * - * This is intended to be used in conjunction with Frederic Weisbecker's - * adaptive-idle work, which would seriously reduce OS jitter on CPUs - * running CPU-bound user-mode computations. - * - * Offloading of callbacks can also be used as an energy-efficiency - * measure because CPUs with no RCU callbacks queued are more aggressive - * about entering dyntick-idle mode. - */ - - -/* - * Parse the boot-time rcu_nocb_mask CPU list from the kernel parameters. - * If the list is invalid, a warning is emitted and all CPUs are offloaded. - */ -static int __init rcu_nocb_setup(char *str) -{ - alloc_bootmem_cpumask_var(&rcu_nocb_mask); - if (cpulist_parse(str, rcu_nocb_mask)) { - pr_warn("rcu_nocbs= bad CPU range, all CPUs set\n"); - cpumask_setall(rcu_nocb_mask); - } - return 1; -} -__setup("rcu_nocbs=", rcu_nocb_setup); - -static int __init parse_rcu_nocb_poll(char *arg) -{ - rcu_nocb_poll = true; - return 0; -} -early_param("rcu_nocb_poll", parse_rcu_nocb_poll); - -/* - * Don't bother bypassing ->cblist if the call_rcu() rate is low. - * After all, the main point of bypassing is to avoid lock contention - * on ->nocb_lock, which only can happen at high call_rcu() rates. - */ -static int nocb_nobypass_lim_per_jiffy = 16 * 1000 / HZ; -module_param(nocb_nobypass_lim_per_jiffy, int, 0); - -/* - * Acquire the specified rcu_data structure's ->nocb_bypass_lock. If the - * lock isn't immediately available, increment ->nocb_lock_contended to - * flag the contention. - */ -static void rcu_nocb_bypass_lock(struct rcu_data *rdp) - __acquires(&rdp->nocb_bypass_lock) -{ - lockdep_assert_irqs_disabled(); - if (raw_spin_trylock(&rdp->nocb_bypass_lock)) - return; - atomic_inc(&rdp->nocb_lock_contended); - WARN_ON_ONCE(smp_processor_id() != rdp->cpu); - smp_mb__after_atomic(); /* atomic_inc() before lock. */ - raw_spin_lock(&rdp->nocb_bypass_lock); - smp_mb__before_atomic(); /* atomic_dec() after lock. */ - atomic_dec(&rdp->nocb_lock_contended); -} - -/* - * Spinwait until the specified rcu_data structure's ->nocb_lock is - * not contended. Please note that this is extremely special-purpose, - * relying on the fact that at most two kthreads and one CPU contend for - * this lock, and also that the two kthreads are guaranteed to have frequent - * grace-period-duration time intervals between successive acquisitions - * of the lock. This allows us to use an extremely simple throttling - * mechanism, and further to apply it only to the CPU doing floods of - * call_rcu() invocations. Don't try this at home! - */ -static void rcu_nocb_wait_contended(struct rcu_data *rdp) -{ - WARN_ON_ONCE(smp_processor_id() != rdp->cpu); - while (WARN_ON_ONCE(atomic_read(&rdp->nocb_lock_contended))) - cpu_relax(); -} - -/* - * Conditionally acquire the specified rcu_data structure's - * ->nocb_bypass_lock. - */ -static bool rcu_nocb_bypass_trylock(struct rcu_data *rdp) -{ - lockdep_assert_irqs_disabled(); - return raw_spin_trylock(&rdp->nocb_bypass_lock); -} - -/* - * Release the specified rcu_data structure's ->nocb_bypass_lock. - */ -static void rcu_nocb_bypass_unlock(struct rcu_data *rdp) - __releases(&rdp->nocb_bypass_lock) -{ - lockdep_assert_irqs_disabled(); - raw_spin_unlock(&rdp->nocb_bypass_lock); -} - -/* - * Acquire the specified rcu_data structure's ->nocb_lock, but only - * if it corresponds to a no-CBs CPU. - */ -static void rcu_nocb_lock(struct rcu_data *rdp) -{ - lockdep_assert_irqs_disabled(); - if (!rcu_rdp_is_offloaded(rdp)) - return; - raw_spin_lock(&rdp->nocb_lock); -} - -/* - * Release the specified rcu_data structure's ->nocb_lock, but only - * if it corresponds to a no-CBs CPU. - */ -static void rcu_nocb_unlock(struct rcu_data *rdp) -{ - if (rcu_rdp_is_offloaded(rdp)) { - lockdep_assert_irqs_disabled(); - raw_spin_unlock(&rdp->nocb_lock); - } -} - -/* - * Release the specified rcu_data structure's ->nocb_lock and restore - * interrupts, but only if it corresponds to a no-CBs CPU. - */ -static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp, - unsigned long flags) -{ - if (rcu_rdp_is_offloaded(rdp)) { - lockdep_assert_irqs_disabled(); - raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); - } else { - local_irq_restore(flags); - } -} - -/* Lockdep check that ->cblist may be safely accessed. */ -static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp) -{ - lockdep_assert_irqs_disabled(); - if (rcu_rdp_is_offloaded(rdp)) - lockdep_assert_held(&rdp->nocb_lock); -} - -/* - * Wake up any no-CBs CPUs' kthreads that were waiting on the just-ended - * grace period. - */ -static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq) -{ - swake_up_all(sq); -} - -static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp) -{ - return &rnp->nocb_gp_wq[rcu_seq_ctr(rnp->gp_seq) & 0x1]; -} - -static void rcu_init_one_nocb(struct rcu_node *rnp) -{ - init_swait_queue_head(&rnp->nocb_gp_wq[0]); - init_swait_queue_head(&rnp->nocb_gp_wq[1]); -} - -/* Is the specified CPU a no-CBs CPU? */ -bool rcu_is_nocb_cpu(int cpu) -{ - if (cpumask_available(rcu_nocb_mask)) - return cpumask_test_cpu(cpu, rcu_nocb_mask); - return false; -} - -static bool __wake_nocb_gp(struct rcu_data *rdp_gp, - struct rcu_data *rdp, - bool force, unsigned long flags) - __releases(rdp_gp->nocb_gp_lock) -{ - bool needwake = false; - - if (!READ_ONCE(rdp_gp->nocb_gp_kthread)) { - raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("AlreadyAwake")); - return false; - } - - if (rdp_gp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) { - WRITE_ONCE(rdp_gp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT); - del_timer(&rdp_gp->nocb_timer); - } - - if (force || READ_ONCE(rdp_gp->nocb_gp_sleep)) { - WRITE_ONCE(rdp_gp->nocb_gp_sleep, false); - needwake = true; - } - raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); - if (needwake) { - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DoWake")); - wake_up_process(rdp_gp->nocb_gp_kthread); - } - - return needwake; -} - -/* - * Kick the GP kthread for this NOCB group. - */ -static bool wake_nocb_gp(struct rcu_data *rdp, bool force) -{ - unsigned long flags; - struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; - - raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); - return __wake_nocb_gp(rdp_gp, rdp, force, flags); -} - -/* - * Arrange to wake the GP kthread for this NOCB group at some future - * time when it is safe to do so. - */ -static void wake_nocb_gp_defer(struct rcu_data *rdp, int waketype, - const char *reason) -{ - unsigned long flags; - struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; - - raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); - - /* - * Bypass wakeup overrides previous deferments. In case - * of callback storm, no need to wake up too early. - */ - if (waketype == RCU_NOCB_WAKE_BYPASS) { - mod_timer(&rdp_gp->nocb_timer, jiffies + 2); - WRITE_ONCE(rdp_gp->nocb_defer_wakeup, waketype); - } else { - if (rdp_gp->nocb_defer_wakeup < RCU_NOCB_WAKE) - mod_timer(&rdp_gp->nocb_timer, jiffies + 1); - if (rdp_gp->nocb_defer_wakeup < waketype) - WRITE_ONCE(rdp_gp->nocb_defer_wakeup, waketype); - } - - raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); - - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, reason); -} - -/* - * Flush the ->nocb_bypass queue into ->cblist, enqueuing rhp if non-NULL. - * However, if there is a callback to be enqueued and if ->nocb_bypass - * proves to be initially empty, just return false because the no-CB GP - * kthread may need to be awakened in this case. - * - * Note that this function always returns true if rhp is NULL. - */ -static bool rcu_nocb_do_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, - unsigned long j) -{ - struct rcu_cblist rcl; - - WARN_ON_ONCE(!rcu_rdp_is_offloaded(rdp)); - rcu_lockdep_assert_cblist_protected(rdp); - lockdep_assert_held(&rdp->nocb_bypass_lock); - if (rhp && !rcu_cblist_n_cbs(&rdp->nocb_bypass)) { - raw_spin_unlock(&rdp->nocb_bypass_lock); - return false; - } - /* Note: ->cblist.len already accounts for ->nocb_bypass contents. */ - if (rhp) - rcu_segcblist_inc_len(&rdp->cblist); /* Must precede enqueue. */ - rcu_cblist_flush_enqueue(&rcl, &rdp->nocb_bypass, rhp); - rcu_segcblist_insert_pend_cbs(&rdp->cblist, &rcl); - WRITE_ONCE(rdp->nocb_bypass_first, j); - rcu_nocb_bypass_unlock(rdp); - return true; -} - -/* - * Flush the ->nocb_bypass queue into ->cblist, enqueuing rhp if non-NULL. - * However, if there is a callback to be enqueued and if ->nocb_bypass - * proves to be initially empty, just return false because the no-CB GP - * kthread may need to be awakened in this case. - * - * Note that this function always returns true if rhp is NULL. - */ -static bool rcu_nocb_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, - unsigned long j) -{ - if (!rcu_rdp_is_offloaded(rdp)) - return true; - rcu_lockdep_assert_cblist_protected(rdp); - rcu_nocb_bypass_lock(rdp); - return rcu_nocb_do_flush_bypass(rdp, rhp, j); -} - -/* - * If the ->nocb_bypass_lock is immediately available, flush the - * ->nocb_bypass queue into ->cblist. - */ -static void rcu_nocb_try_flush_bypass(struct rcu_data *rdp, unsigned long j) -{ - rcu_lockdep_assert_cblist_protected(rdp); - if (!rcu_rdp_is_offloaded(rdp) || - !rcu_nocb_bypass_trylock(rdp)) - return; - WARN_ON_ONCE(!rcu_nocb_do_flush_bypass(rdp, NULL, j)); -} - -/* - * See whether it is appropriate to use the ->nocb_bypass list in order - * to control contention on ->nocb_lock. A limited number of direct - * enqueues are permitted into ->cblist per jiffy. If ->nocb_bypass - * is non-empty, further callbacks must be placed into ->nocb_bypass, - * otherwise rcu_barrier() breaks. Use rcu_nocb_flush_bypass() to switch - * back to direct use of ->cblist. However, ->nocb_bypass should not be - * used if ->cblist is empty, because otherwise callbacks can be stranded - * on ->nocb_bypass because we cannot count on the current CPU ever again - * invoking call_rcu(). The general rule is that if ->nocb_bypass is - * non-empty, the corresponding no-CBs grace-period kthread must not be - * in an indefinite sleep state. - * - * Finally, it is not permitted to use the bypass during early boot, - * as doing so would confuse the auto-initialization code. Besides - * which, there is no point in worrying about lock contention while - * there is only one CPU in operation. - */ -static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp, - bool *was_alldone, unsigned long flags) -{ - unsigned long c; - unsigned long cur_gp_seq; - unsigned long j = jiffies; - long ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); - - lockdep_assert_irqs_disabled(); - - // Pure softirq/rcuc based processing: no bypassing, no - // locking. - if (!rcu_rdp_is_offloaded(rdp)) { - *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); - return false; - } - - // In the process of (de-)offloading: no bypassing, but - // locking. - if (!rcu_segcblist_completely_offloaded(&rdp->cblist)) { - rcu_nocb_lock(rdp); - *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); - return false; /* Not offloaded, no bypassing. */ - } - - // Don't use ->nocb_bypass during early boot. - if (rcu_scheduler_active != RCU_SCHEDULER_RUNNING) { - rcu_nocb_lock(rdp); - WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); - *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); - return false; - } - - // If we have advanced to a new jiffy, reset counts to allow - // moving back from ->nocb_bypass to ->cblist. - if (j == rdp->nocb_nobypass_last) { - c = rdp->nocb_nobypass_count + 1; - } else { - WRITE_ONCE(rdp->nocb_nobypass_last, j); - c = rdp->nocb_nobypass_count - nocb_nobypass_lim_per_jiffy; - if (ULONG_CMP_LT(rdp->nocb_nobypass_count, - nocb_nobypass_lim_per_jiffy)) - c = 0; - else if (c > nocb_nobypass_lim_per_jiffy) - c = nocb_nobypass_lim_per_jiffy; - } - WRITE_ONCE(rdp->nocb_nobypass_count, c); - - // If there hasn't yet been all that many ->cblist enqueues - // this jiffy, tell the caller to enqueue onto ->cblist. But flush - // ->nocb_bypass first. - if (rdp->nocb_nobypass_count < nocb_nobypass_lim_per_jiffy) { - rcu_nocb_lock(rdp); - *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); - if (*was_alldone) - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("FirstQ")); - WARN_ON_ONCE(!rcu_nocb_flush_bypass(rdp, NULL, j)); - WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); - return false; // Caller must enqueue the callback. - } - - // If ->nocb_bypass has been used too long or is too full, - // flush ->nocb_bypass to ->cblist. - if ((ncbs && j != READ_ONCE(rdp->nocb_bypass_first)) || - ncbs >= qhimark) { - rcu_nocb_lock(rdp); - if (!rcu_nocb_flush_bypass(rdp, rhp, j)) { - *was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist); - if (*was_alldone) - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("FirstQ")); - WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); - return false; // Caller must enqueue the callback. - } - if (j != rdp->nocb_gp_adv_time && - rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq) && - rcu_seq_done(&rdp->mynode->gp_seq, cur_gp_seq)) { - rcu_advance_cbs_nowake(rdp->mynode, rdp); - rdp->nocb_gp_adv_time = j; - } - rcu_nocb_unlock_irqrestore(rdp, flags); - return true; // Callback already enqueued. - } - - // We need to use the bypass. - rcu_nocb_wait_contended(rdp); - rcu_nocb_bypass_lock(rdp); - ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); - rcu_segcblist_inc_len(&rdp->cblist); /* Must precede enqueue. */ - rcu_cblist_enqueue(&rdp->nocb_bypass, rhp); - if (!ncbs) { - WRITE_ONCE(rdp->nocb_bypass_first, j); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("FirstBQ")); - } - rcu_nocb_bypass_unlock(rdp); - smp_mb(); /* Order enqueue before wake. */ - if (ncbs) { - local_irq_restore(flags); - } else { - // No-CBs GP kthread might be indefinitely asleep, if so, wake. - rcu_nocb_lock(rdp); // Rare during call_rcu() flood. - if (!rcu_segcblist_pend_cbs(&rdp->cblist)) { - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("FirstBQwake")); - __call_rcu_nocb_wake(rdp, true, flags); - } else { - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("FirstBQnoWake")); - rcu_nocb_unlock_irqrestore(rdp, flags); - } - } - return true; // Callback already enqueued. -} - -/* - * Awaken the no-CBs grace-period kthread if needed, either due to it - * legitimately being asleep or due to overload conditions. - * - * If warranted, also wake up the kthread servicing this CPUs queues. - */ -static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone, - unsigned long flags) - __releases(rdp->nocb_lock) -{ - unsigned long cur_gp_seq; - unsigned long j; - long len; - struct task_struct *t; - - // If we are being polled or there is no kthread, just leave. - t = READ_ONCE(rdp->nocb_gp_kthread); - if (rcu_nocb_poll || !t) { - rcu_nocb_unlock_irqrestore(rdp, flags); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("WakeNotPoll")); - return; - } - // Need to actually to a wakeup. - len = rcu_segcblist_n_cbs(&rdp->cblist); - if (was_alldone) { - rdp->qlen_last_fqs_check = len; - if (!irqs_disabled_flags(flags)) { - /* ... if queue was empty ... */ - rcu_nocb_unlock_irqrestore(rdp, flags); - wake_nocb_gp(rdp, false); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("WakeEmpty")); - } else { - rcu_nocb_unlock_irqrestore(rdp, flags); - wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE, - TPS("WakeEmptyIsDeferred")); - } - } else if (len > rdp->qlen_last_fqs_check + qhimark) { - /* ... or if many callbacks queued. */ - rdp->qlen_last_fqs_check = len; - j = jiffies; - if (j != rdp->nocb_gp_adv_time && - rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq) && - rcu_seq_done(&rdp->mynode->gp_seq, cur_gp_seq)) { - rcu_advance_cbs_nowake(rdp->mynode, rdp); - rdp->nocb_gp_adv_time = j; - } - smp_mb(); /* Enqueue before timer_pending(). */ - if ((rdp->nocb_cb_sleep || - !rcu_segcblist_ready_cbs(&rdp->cblist)) && - !timer_pending(&rdp->nocb_timer)) { - rcu_nocb_unlock_irqrestore(rdp, flags); - wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE_FORCE, - TPS("WakeOvfIsDeferred")); - } else { - rcu_nocb_unlock_irqrestore(rdp, flags); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeNot")); - } - } else { - rcu_nocb_unlock_irqrestore(rdp, flags); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeNot")); - } - return; -} - -/* - * Check if we ignore this rdp. - * - * We check that without holding the nocb lock but - * we make sure not to miss a freshly offloaded rdp - * with the current ordering: - * - * rdp_offload_toggle() nocb_gp_enabled_cb() - * ------------------------- ---------------------------- - * WRITE flags LOCK nocb_gp_lock - * LOCK nocb_gp_lock READ/WRITE nocb_gp_sleep - * READ/WRITE nocb_gp_sleep UNLOCK nocb_gp_lock - * UNLOCK nocb_gp_lock READ flags - */ -static inline bool nocb_gp_enabled_cb(struct rcu_data *rdp) -{ - u8 flags = SEGCBLIST_OFFLOADED | SEGCBLIST_KTHREAD_GP; - - return rcu_segcblist_test_flags(&rdp->cblist, flags); -} - -static inline bool nocb_gp_update_state_deoffloading(struct rcu_data *rdp, - bool *needwake_state) -{ - struct rcu_segcblist *cblist = &rdp->cblist; - - if (rcu_segcblist_test_flags(cblist, SEGCBLIST_OFFLOADED)) { - if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)) { - rcu_segcblist_set_flags(cblist, SEGCBLIST_KTHREAD_GP); - if (rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)) - *needwake_state = true; - } - return false; - } - - /* - * De-offloading. Clear our flag and notify the de-offload worker. - * We will ignore this rdp until it ever gets re-offloaded. - */ - WARN_ON_ONCE(!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)); - rcu_segcblist_clear_flags(cblist, SEGCBLIST_KTHREAD_GP); - if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)) - *needwake_state = true; - return true; -} - - -/* - * No-CBs GP kthreads come here to wait for additional callbacks to show up - * or for grace periods to end. - */ -static void nocb_gp_wait(struct rcu_data *my_rdp) -{ - bool bypass = false; - long bypass_ncbs; - int __maybe_unused cpu = my_rdp->cpu; - unsigned long cur_gp_seq; - unsigned long flags; - bool gotcbs = false; - unsigned long j = jiffies; - bool needwait_gp = false; // This prevents actual uninitialized use. - bool needwake; - bool needwake_gp; - struct rcu_data *rdp; - struct rcu_node *rnp; - unsigned long wait_gp_seq = 0; // Suppress "use uninitialized" warning. - bool wasempty = false; - - /* - * Each pass through the following loop checks for CBs and for the - * nearest grace period (if any) to wait for next. The CB kthreads - * and the global grace-period kthread are awakened if needed. - */ - WARN_ON_ONCE(my_rdp->nocb_gp_rdp != my_rdp); - for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_cb_rdp) { - bool needwake_state = false; - - if (!nocb_gp_enabled_cb(rdp)) - continue; - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Check")); - rcu_nocb_lock_irqsave(rdp, flags); - if (nocb_gp_update_state_deoffloading(rdp, &needwake_state)) { - rcu_nocb_unlock_irqrestore(rdp, flags); - if (needwake_state) - swake_up_one(&rdp->nocb_state_wq); - continue; - } - bypass_ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); - if (bypass_ncbs && - (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + 1) || - bypass_ncbs > 2 * qhimark)) { - // Bypass full or old, so flush it. - (void)rcu_nocb_try_flush_bypass(rdp, j); - bypass_ncbs = rcu_cblist_n_cbs(&rdp->nocb_bypass); - } else if (!bypass_ncbs && rcu_segcblist_empty(&rdp->cblist)) { - rcu_nocb_unlock_irqrestore(rdp, flags); - if (needwake_state) - swake_up_one(&rdp->nocb_state_wq); - continue; /* No callbacks here, try next. */ - } - if (bypass_ncbs) { - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("Bypass")); - bypass = true; - } - rnp = rdp->mynode; - - // Advance callbacks if helpful and low contention. - needwake_gp = false; - if (!rcu_segcblist_restempty(&rdp->cblist, - RCU_NEXT_READY_TAIL) || - (rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq) && - rcu_seq_done(&rnp->gp_seq, cur_gp_seq))) { - raw_spin_lock_rcu_node(rnp); /* irqs disabled. */ - needwake_gp = rcu_advance_cbs(rnp, rdp); - wasempty = rcu_segcblist_restempty(&rdp->cblist, - RCU_NEXT_READY_TAIL); - raw_spin_unlock_rcu_node(rnp); /* irqs disabled. */ - } - // Need to wait on some grace period? - WARN_ON_ONCE(wasempty && - !rcu_segcblist_restempty(&rdp->cblist, - RCU_NEXT_READY_TAIL)); - if (rcu_segcblist_nextgp(&rdp->cblist, &cur_gp_seq)) { - if (!needwait_gp || - ULONG_CMP_LT(cur_gp_seq, wait_gp_seq)) - wait_gp_seq = cur_gp_seq; - needwait_gp = true; - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, - TPS("NeedWaitGP")); - } - if (rcu_segcblist_ready_cbs(&rdp->cblist)) { - needwake = rdp->nocb_cb_sleep; - WRITE_ONCE(rdp->nocb_cb_sleep, false); - smp_mb(); /* CB invocation -after- GP end. */ - } else { - needwake = false; - } - rcu_nocb_unlock_irqrestore(rdp, flags); - if (needwake) { - swake_up_one(&rdp->nocb_cb_wq); - gotcbs = true; - } - if (needwake_gp) - rcu_gp_kthread_wake(); - if (needwake_state) - swake_up_one(&rdp->nocb_state_wq); - } - - my_rdp->nocb_gp_bypass = bypass; - my_rdp->nocb_gp_gp = needwait_gp; - my_rdp->nocb_gp_seq = needwait_gp ? wait_gp_seq : 0; - - if (bypass && !rcu_nocb_poll) { - // At least one child with non-empty ->nocb_bypass, so set - // timer in order to avoid stranding its callbacks. - wake_nocb_gp_defer(my_rdp, RCU_NOCB_WAKE_BYPASS, - TPS("WakeBypassIsDeferred")); - } - if (rcu_nocb_poll) { - /* Polling, so trace if first poll in the series. */ - if (gotcbs) - trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Poll")); - schedule_timeout_idle(1); - } else if (!needwait_gp) { - /* Wait for callbacks to appear. */ - trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("Sleep")); - swait_event_interruptible_exclusive(my_rdp->nocb_gp_wq, - !READ_ONCE(my_rdp->nocb_gp_sleep)); - trace_rcu_nocb_wake(rcu_state.name, cpu, TPS("EndSleep")); - } else { - rnp = my_rdp->mynode; - trace_rcu_this_gp(rnp, my_rdp, wait_gp_seq, TPS("StartWait")); - swait_event_interruptible_exclusive( - rnp->nocb_gp_wq[rcu_seq_ctr(wait_gp_seq) & 0x1], - rcu_seq_done(&rnp->gp_seq, wait_gp_seq) || - !READ_ONCE(my_rdp->nocb_gp_sleep)); - trace_rcu_this_gp(rnp, my_rdp, wait_gp_seq, TPS("EndWait")); - } - if (!rcu_nocb_poll) { - raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags); - if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) { - WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT); - del_timer(&my_rdp->nocb_timer); - } - WRITE_ONCE(my_rdp->nocb_gp_sleep, true); - raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags); - } - my_rdp->nocb_gp_seq = -1; - WARN_ON(signal_pending(current)); -} - -/* - * No-CBs grace-period-wait kthread. There is one of these per group - * of CPUs, but only once at least one CPU in that group has come online - * at least once since boot. This kthread checks for newly posted - * callbacks from any of the CPUs it is responsible for, waits for a - * grace period, then awakens all of the rcu_nocb_cb_kthread() instances - * that then have callback-invocation work to do. - */ -static int rcu_nocb_gp_kthread(void *arg) -{ - struct rcu_data *rdp = arg; - - for (;;) { - WRITE_ONCE(rdp->nocb_gp_loops, rdp->nocb_gp_loops + 1); - nocb_gp_wait(rdp); - cond_resched_tasks_rcu_qs(); - } - return 0; -} - -static inline bool nocb_cb_can_run(struct rcu_data *rdp) -{ - u8 flags = SEGCBLIST_OFFLOADED | SEGCBLIST_KTHREAD_CB; - return rcu_segcblist_test_flags(&rdp->cblist, flags); -} - -static inline bool nocb_cb_wait_cond(struct rcu_data *rdp) -{ - return nocb_cb_can_run(rdp) && !READ_ONCE(rdp->nocb_cb_sleep); -} - -/* - * Invoke any ready callbacks from the corresponding no-CBs CPU, - * then, if there are no more, wait for more to appear. - */ -static void nocb_cb_wait(struct rcu_data *rdp) -{ - struct rcu_segcblist *cblist = &rdp->cblist; - unsigned long cur_gp_seq; - unsigned long flags; - bool needwake_state = false; - bool needwake_gp = false; - bool can_sleep = true; - struct rcu_node *rnp = rdp->mynode; - - local_irq_save(flags); - rcu_momentary_dyntick_idle(); - local_irq_restore(flags); - /* - * Disable BH to provide the expected environment. Also, when - * transitioning to/from NOCB mode, a self-requeuing callback might - * be invoked from softirq. A short grace period could cause both - * instances of this callback would execute concurrently. - */ - local_bh_disable(); - rcu_do_batch(rdp); - local_bh_enable(); - lockdep_assert_irqs_enabled(); - rcu_nocb_lock_irqsave(rdp, flags); - if (rcu_segcblist_nextgp(cblist, &cur_gp_seq) && - rcu_seq_done(&rnp->gp_seq, cur_gp_seq) && - raw_spin_trylock_rcu_node(rnp)) { /* irqs already disabled. */ - needwake_gp = rcu_advance_cbs(rdp->mynode, rdp); - raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */ - } - - if (rcu_segcblist_test_flags(cblist, SEGCBLIST_OFFLOADED)) { - if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)) { - rcu_segcblist_set_flags(cblist, SEGCBLIST_KTHREAD_CB); - if (rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)) - needwake_state = true; - } - if (rcu_segcblist_ready_cbs(cblist)) - can_sleep = false; - } else { - /* - * De-offloading. Clear our flag and notify the de-offload worker. - * We won't touch the callbacks and keep sleeping until we ever - * get re-offloaded. - */ - WARN_ON_ONCE(!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB)); - rcu_segcblist_clear_flags(cblist, SEGCBLIST_KTHREAD_CB); - if (!rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)) - needwake_state = true; - } - - WRITE_ONCE(rdp->nocb_cb_sleep, can_sleep); - - if (rdp->nocb_cb_sleep) - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("CBSleep")); - - rcu_nocb_unlock_irqrestore(rdp, flags); - if (needwake_gp) - rcu_gp_kthread_wake(); - - if (needwake_state) - swake_up_one(&rdp->nocb_state_wq); - - do { - swait_event_interruptible_exclusive(rdp->nocb_cb_wq, - nocb_cb_wait_cond(rdp)); - - // VVV Ensure CB invocation follows _sleep test. - if (smp_load_acquire(&rdp->nocb_cb_sleep)) { // ^^^ - WARN_ON(signal_pending(current)); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WokeEmpty")); - } - } while (!nocb_cb_can_run(rdp)); -} - -/* - * Per-rcu_data kthread, but only for no-CBs CPUs. Repeatedly invoke - * nocb_cb_wait() to do the dirty work. - */ -static int rcu_nocb_cb_kthread(void *arg) -{ - struct rcu_data *rdp = arg; - - // Each pass through this loop does one callback batch, and, - // if there are no more ready callbacks, waits for them. - for (;;) { - nocb_cb_wait(rdp); - cond_resched_tasks_rcu_qs(); - } - return 0; -} - -/* Is a deferred wakeup of rcu_nocb_kthread() required? */ -static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp, int level) -{ - return READ_ONCE(rdp->nocb_defer_wakeup) >= level; -} - -/* Do a deferred wakeup of rcu_nocb_kthread(). */ -static bool do_nocb_deferred_wakeup_common(struct rcu_data *rdp_gp, - struct rcu_data *rdp, int level, - unsigned long flags) - __releases(rdp_gp->nocb_gp_lock) -{ - int ndw; - int ret; - - if (!rcu_nocb_need_deferred_wakeup(rdp_gp, level)) { - raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); - return false; - } - - ndw = rdp_gp->nocb_defer_wakeup; - ret = __wake_nocb_gp(rdp_gp, rdp, ndw == RCU_NOCB_WAKE_FORCE, flags); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("DeferredWake")); - - return ret; -} - -/* Do a deferred wakeup of rcu_nocb_kthread() from a timer handler. */ -static void do_nocb_deferred_wakeup_timer(struct timer_list *t) -{ - unsigned long flags; - struct rcu_data *rdp = from_timer(rdp, t, nocb_timer); - - WARN_ON_ONCE(rdp->nocb_gp_rdp != rdp); - trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Timer")); - - raw_spin_lock_irqsave(&rdp->nocb_gp_lock, flags); - smp_mb__after_spinlock(); /* Timer expire before wakeup. */ - do_nocb_deferred_wakeup_common(rdp, rdp, RCU_NOCB_WAKE_BYPASS, flags); -} - -/* - * Do a deferred wakeup of rcu_nocb_kthread() from fastpath. - * This means we do an inexact common-case check. Note that if - * we miss, ->nocb_timer will eventually clean things up. - */ -static bool do_nocb_deferred_wakeup(struct rcu_data *rdp) -{ - unsigned long flags; - struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; - - if (!rdp_gp || !rcu_nocb_need_deferred_wakeup(rdp_gp, RCU_NOCB_WAKE)) - return false; - - raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); - return do_nocb_deferred_wakeup_common(rdp_gp, rdp, RCU_NOCB_WAKE, flags); -} - -void rcu_nocb_flush_deferred_wakeup(void) -{ - do_nocb_deferred_wakeup(this_cpu_ptr(&rcu_data)); -} -EXPORT_SYMBOL_GPL(rcu_nocb_flush_deferred_wakeup); - -static int rdp_offload_toggle(struct rcu_data *rdp, - bool offload, unsigned long flags) - __releases(rdp->nocb_lock) -{ - struct rcu_segcblist *cblist = &rdp->cblist; - struct rcu_data *rdp_gp = rdp->nocb_gp_rdp; - bool wake_gp = false; - - rcu_segcblist_offload(cblist, offload); - - if (rdp->nocb_cb_sleep) - rdp->nocb_cb_sleep = false; - rcu_nocb_unlock_irqrestore(rdp, flags); - - /* - * Ignore former value of nocb_cb_sleep and force wake up as it could - * have been spuriously set to false already. - */ - swake_up_one(&rdp->nocb_cb_wq); - - raw_spin_lock_irqsave(&rdp_gp->nocb_gp_lock, flags); - if (rdp_gp->nocb_gp_sleep) { - rdp_gp->nocb_gp_sleep = false; - wake_gp = true; - } - raw_spin_unlock_irqrestore(&rdp_gp->nocb_gp_lock, flags); - - if (wake_gp) - wake_up_process(rdp_gp->nocb_gp_kthread); - - return 0; -} - -static long rcu_nocb_rdp_deoffload(void *arg) -{ - struct rcu_data *rdp = arg; - struct rcu_segcblist *cblist = &rdp->cblist; - unsigned long flags; - int ret; - - WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); - - pr_info("De-offloading %d\n", rdp->cpu); - - rcu_nocb_lock_irqsave(rdp, flags); - /* - * Flush once and for all now. This suffices because we are - * running on the target CPU holding ->nocb_lock (thus having - * interrupts disabled), and because rdp_offload_toggle() - * invokes rcu_segcblist_offload(), which clears SEGCBLIST_OFFLOADED. - * Thus future calls to rcu_segcblist_completely_offloaded() will - * return false, which means that future calls to rcu_nocb_try_bypass() - * will refuse to put anything into the bypass. - */ - WARN_ON_ONCE(!rcu_nocb_flush_bypass(rdp, NULL, jiffies)); - ret = rdp_offload_toggle(rdp, false, flags); - swait_event_exclusive(rdp->nocb_state_wq, - !rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB | - SEGCBLIST_KTHREAD_GP)); - /* - * Lock one last time to acquire latest callback updates from kthreads - * so we can later handle callbacks locally without locking. - */ - rcu_nocb_lock_irqsave(rdp, flags); - /* - * Theoretically we could set SEGCBLIST_SOFTIRQ_ONLY after the nocb - * lock is released but how about being paranoid for once? - */ - rcu_segcblist_set_flags(cblist, SEGCBLIST_SOFTIRQ_ONLY); - /* - * With SEGCBLIST_SOFTIRQ_ONLY, we can't use - * rcu_nocb_unlock_irqrestore() anymore. - */ - raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); - - /* Sanity check */ - WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); - - - return ret; -} - -int rcu_nocb_cpu_deoffload(int cpu) -{ - struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); - int ret = 0; - - mutex_lock(&rcu_state.barrier_mutex); - cpus_read_lock(); - if (rcu_rdp_is_offloaded(rdp)) { - if (cpu_online(cpu)) { - ret = work_on_cpu(cpu, rcu_nocb_rdp_deoffload, rdp); - if (!ret) - cpumask_clear_cpu(cpu, rcu_nocb_mask); - } else { - pr_info("NOCB: Can't CB-deoffload an offline CPU\n"); - ret = -EINVAL; - } - } - cpus_read_unlock(); - mutex_unlock(&rcu_state.barrier_mutex); - - return ret; -} -EXPORT_SYMBOL_GPL(rcu_nocb_cpu_deoffload); - -static long rcu_nocb_rdp_offload(void *arg) -{ - struct rcu_data *rdp = arg; - struct rcu_segcblist *cblist = &rdp->cblist; - unsigned long flags; - int ret; - - WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); - /* - * For now we only support re-offload, ie: the rdp must have been - * offloaded on boot first. - */ - if (!rdp->nocb_gp_rdp) - return -EINVAL; - - pr_info("Offloading %d\n", rdp->cpu); - /* - * Can't use rcu_nocb_lock_irqsave() while we are in - * SEGCBLIST_SOFTIRQ_ONLY mode. - */ - raw_spin_lock_irqsave(&rdp->nocb_lock, flags); - - /* - * We didn't take the nocb lock while working on the - * rdp->cblist in SEGCBLIST_SOFTIRQ_ONLY mode. - * Every modifications that have been done previously on - * rdp->cblist must be visible remotely by the nocb kthreads - * upon wake up after reading the cblist flags. - * - * The layout against nocb_lock enforces that ordering: - * - * __rcu_nocb_rdp_offload() nocb_cb_wait()/nocb_gp_wait() - * ------------------------- ---------------------------- - * WRITE callbacks rcu_nocb_lock() - * rcu_nocb_lock() READ flags - * WRITE flags READ callbacks - * rcu_nocb_unlock() rcu_nocb_unlock() - */ - ret = rdp_offload_toggle(rdp, true, flags); - swait_event_exclusive(rdp->nocb_state_wq, - rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB) && - rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_GP)); - - return ret; -} - -int rcu_nocb_cpu_offload(int cpu) -{ - struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); - int ret = 0; - - mutex_lock(&rcu_state.barrier_mutex); - cpus_read_lock(); - if (!rcu_rdp_is_offloaded(rdp)) { - if (cpu_online(cpu)) { - ret = work_on_cpu(cpu, rcu_nocb_rdp_offload, rdp); - if (!ret) - cpumask_set_cpu(cpu, rcu_nocb_mask); - } else { - pr_info("NOCB: Can't CB-offload an offline CPU\n"); - ret = -EINVAL; - } - } - cpus_read_unlock(); - mutex_unlock(&rcu_state.barrier_mutex); - - return ret; -} -EXPORT_SYMBOL_GPL(rcu_nocb_cpu_offload); - -void __init rcu_init_nohz(void) -{ - int cpu; - bool need_rcu_nocb_mask = false; - struct rcu_data *rdp; - -#if defined(CONFIG_NO_HZ_FULL) - if (tick_nohz_full_running && cpumask_weight(tick_nohz_full_mask)) - need_rcu_nocb_mask = true; -#endif /* #if defined(CONFIG_NO_HZ_FULL) */ - - if (!cpumask_available(rcu_nocb_mask) && need_rcu_nocb_mask) { - if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { - pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); - return; - } - } - if (!cpumask_available(rcu_nocb_mask)) - return; - -#if defined(CONFIG_NO_HZ_FULL) - if (tick_nohz_full_running) - cpumask_or(rcu_nocb_mask, rcu_nocb_mask, tick_nohz_full_mask); -#endif /* #if defined(CONFIG_NO_HZ_FULL) */ - - if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { - pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n"); - cpumask_and(rcu_nocb_mask, cpu_possible_mask, - rcu_nocb_mask); - } - if (cpumask_empty(rcu_nocb_mask)) - pr_info("\tOffload RCU callbacks from CPUs: (none).\n"); - else - pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n", - cpumask_pr_args(rcu_nocb_mask)); - if (rcu_nocb_poll) - pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); - - for_each_cpu(cpu, rcu_nocb_mask) { - rdp = per_cpu_ptr(&rcu_data, cpu); - if (rcu_segcblist_empty(&rdp->cblist)) - rcu_segcblist_init(&rdp->cblist); - rcu_segcblist_offload(&rdp->cblist, true); - rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB); - rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_GP); - } - rcu_organize_nocb_kthreads(); -} - -/* Initialize per-rcu_data variables for no-CBs CPUs. */ -static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) -{ - init_swait_queue_head(&rdp->nocb_cb_wq); - init_swait_queue_head(&rdp->nocb_gp_wq); - init_swait_queue_head(&rdp->nocb_state_wq); - raw_spin_lock_init(&rdp->nocb_lock); - raw_spin_lock_init(&rdp->nocb_bypass_lock); - raw_spin_lock_init(&rdp->nocb_gp_lock); - timer_setup(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer, 0); - rcu_cblist_init(&rdp->nocb_bypass); -} - -/* - * If the specified CPU is a no-CBs CPU that does not already have its - * rcuo CB kthread, spawn it. Additionally, if the rcuo GP kthread - * for this CPU's group has not yet been created, spawn it as well. - */ -static void rcu_spawn_one_nocb_kthread(int cpu) -{ - struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); - struct rcu_data *rdp_gp; - struct task_struct *t; - - /* - * If this isn't a no-CBs CPU or if it already has an rcuo kthread, - * then nothing to do. - */ - if (!rcu_is_nocb_cpu(cpu) || rdp->nocb_cb_kthread) - return; - - /* If we didn't spawn the GP kthread first, reorganize! */ - rdp_gp = rdp->nocb_gp_rdp; - if (!rdp_gp->nocb_gp_kthread) { - t = kthread_run(rcu_nocb_gp_kthread, rdp_gp, - "rcuog/%d", rdp_gp->cpu); - if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo GP kthread, OOM is now expected behavior\n", __func__)) - return; - WRITE_ONCE(rdp_gp->nocb_gp_kthread, t); - } - - /* Spawn the kthread for this CPU. */ - t = kthread_run(rcu_nocb_cb_kthread, rdp, - "rcuo%c/%d", rcu_state.abbr, cpu); - if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo CB kthread, OOM is now expected behavior\n", __func__)) - return; - WRITE_ONCE(rdp->nocb_cb_kthread, t); - WRITE_ONCE(rdp->nocb_gp_kthread, rdp_gp->nocb_gp_kthread); -} - -/* - * If the specified CPU is a no-CBs CPU that does not already have its - * rcuo kthread, spawn it. - */ -static void rcu_spawn_cpu_nocb_kthread(int cpu) -{ - if (rcu_scheduler_fully_active) - rcu_spawn_one_nocb_kthread(cpu); -} - -/* - * Once the scheduler is running, spawn rcuo kthreads for all online - * no-CBs CPUs. This assumes that the early_initcall()s happen before - * non-boot CPUs come online -- if this changes, we will need to add - * some mutual exclusion. - */ -static void __init rcu_spawn_nocb_kthreads(void) -{ - int cpu; - - for_each_online_cpu(cpu) - rcu_spawn_cpu_nocb_kthread(cpu); -} - -/* How many CB CPU IDs per GP kthread? Default of -1 for sqrt(nr_cpu_ids). */ -static int rcu_nocb_gp_stride = -1; -module_param(rcu_nocb_gp_stride, int, 0444); - -/* - * Initialize GP-CB relationships for all no-CBs CPU. - */ -static void __init rcu_organize_nocb_kthreads(void) -{ - int cpu; - bool firsttime = true; - bool gotnocbs = false; - bool gotnocbscbs = true; - int ls = rcu_nocb_gp_stride; - int nl = 0; /* Next GP kthread. */ - struct rcu_data *rdp; - struct rcu_data *rdp_gp = NULL; /* Suppress misguided gcc warn. */ - struct rcu_data *rdp_prev = NULL; - - if (!cpumask_available(rcu_nocb_mask)) - return; - if (ls == -1) { - ls = nr_cpu_ids / int_sqrt(nr_cpu_ids); - rcu_nocb_gp_stride = ls; - } - - /* - * Each pass through this loop sets up one rcu_data structure. - * Should the corresponding CPU come online in the future, then - * we will spawn the needed set of rcu_nocb_kthread() kthreads. - */ - for_each_cpu(cpu, rcu_nocb_mask) { - rdp = per_cpu_ptr(&rcu_data, cpu); - if (rdp->cpu >= nl) { - /* New GP kthread, set up for CBs & next GP. */ - gotnocbs = true; - nl = DIV_ROUND_UP(rdp->cpu + 1, ls) * ls; - rdp->nocb_gp_rdp = rdp; - rdp_gp = rdp; - if (dump_tree) { - if (!firsttime) - pr_cont("%s\n", gotnocbscbs - ? "" : " (self only)"); - gotnocbscbs = false; - firsttime = false; - pr_alert("%s: No-CB GP kthread CPU %d:", - __func__, cpu); - } - } else { - /* Another CB kthread, link to previous GP kthread. */ - gotnocbscbs = true; - rdp->nocb_gp_rdp = rdp_gp; - rdp_prev->nocb_next_cb_rdp = rdp; - if (dump_tree) - pr_cont(" %d", cpu); - } - rdp_prev = rdp; - } - if (gotnocbs && dump_tree) - pr_cont("%s\n", gotnocbscbs ? "" : " (self only)"); -} - -/* - * Bind the current task to the offloaded CPUs. If there are no offloaded - * CPUs, leave the task unbound. Splat if the bind attempt fails. - */ -void rcu_bind_current_to_nocb(void) -{ - if (cpumask_available(rcu_nocb_mask) && cpumask_weight(rcu_nocb_mask)) - WARN_ON(sched_setaffinity(current->pid, rcu_nocb_mask)); -} -EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb); - -// The ->on_cpu field is available only in CONFIG_SMP=y, so... -#ifdef CONFIG_SMP -static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) -{ - return tsp && task_is_running(tsp) && !tsp->on_cpu ? "!" : ""; -} -#else // #ifdef CONFIG_SMP -static char *show_rcu_should_be_on_cpu(struct task_struct *tsp) -{ - return ""; -} -#endif // #else #ifdef CONFIG_SMP - -/* - * Dump out nocb grace-period kthread state for the specified rcu_data - * structure. - */ -static void show_rcu_nocb_gp_state(struct rcu_data *rdp) -{ - struct rcu_node *rnp = rdp->mynode; - - pr_info("nocb GP %d %c%c%c%c%c %c[%c%c] %c%c:%ld rnp %d:%d %lu %c CPU %d%s\n", - rdp->cpu, - "kK"[!!rdp->nocb_gp_kthread], - "lL"[raw_spin_is_locked(&rdp->nocb_gp_lock)], - "dD"[!!rdp->nocb_defer_wakeup], - "tT"[timer_pending(&rdp->nocb_timer)], - "sS"[!!rdp->nocb_gp_sleep], - ".W"[swait_active(&rdp->nocb_gp_wq)], - ".W"[swait_active(&rnp->nocb_gp_wq[0])], - ".W"[swait_active(&rnp->nocb_gp_wq[1])], - ".B"[!!rdp->nocb_gp_bypass], - ".G"[!!rdp->nocb_gp_gp], - (long)rdp->nocb_gp_seq, - rnp->grplo, rnp->grphi, READ_ONCE(rdp->nocb_gp_loops), - rdp->nocb_gp_kthread ? task_state_to_char(rdp->nocb_gp_kthread) : '.', - rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1, - show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread)); -} - -/* Dump out nocb kthread state for the specified rcu_data structure. */ -static void show_rcu_nocb_state(struct rcu_data *rdp) -{ - char bufw[20]; - char bufr[20]; - struct rcu_segcblist *rsclp = &rdp->cblist; - bool waslocked; - bool wassleep; - - if (rdp->nocb_gp_rdp == rdp) - show_rcu_nocb_gp_state(rdp); - - sprintf(bufw, "%ld", rsclp->gp_seq[RCU_WAIT_TAIL]); - sprintf(bufr, "%ld", rsclp->gp_seq[RCU_NEXT_READY_TAIL]); - pr_info(" CB %d^%d->%d %c%c%c%c%c%c F%ld L%ld C%d %c%c%s%c%s%c%c q%ld %c CPU %d%s\n", - rdp->cpu, rdp->nocb_gp_rdp->cpu, - rdp->nocb_next_cb_rdp ? rdp->nocb_next_cb_rdp->cpu : -1, - "kK"[!!rdp->nocb_cb_kthread], - "bB"[raw_spin_is_locked(&rdp->nocb_bypass_lock)], - "cC"[!!atomic_read(&rdp->nocb_lock_contended)], - "lL"[raw_spin_is_locked(&rdp->nocb_lock)], - "sS"[!!rdp->nocb_cb_sleep], - ".W"[swait_active(&rdp->nocb_cb_wq)], - jiffies - rdp->nocb_bypass_first, - jiffies - rdp->nocb_nobypass_last, - rdp->nocb_nobypass_count, - ".D"[rcu_segcblist_ready_cbs(rsclp)], - ".W"[!rcu_segcblist_segempty(rsclp, RCU_WAIT_TAIL)], - rcu_segcblist_segempty(rsclp, RCU_WAIT_TAIL) ? "" : bufw, - ".R"[!rcu_segcblist_segempty(rsclp, RCU_NEXT_READY_TAIL)], - rcu_segcblist_segempty(rsclp, RCU_NEXT_READY_TAIL) ? "" : bufr, - ".N"[!rcu_segcblist_segempty(rsclp, RCU_NEXT_TAIL)], - ".B"[!!rcu_cblist_n_cbs(&rdp->nocb_bypass)], - rcu_segcblist_n_cbs(&rdp->cblist), - rdp->nocb_cb_kthread ? task_state_to_char(rdp->nocb_cb_kthread) : '.', - rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1, - show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread)); - - /* It is OK for GP kthreads to have GP state. */ - if (rdp->nocb_gp_rdp == rdp) - return; - - waslocked = raw_spin_is_locked(&rdp->nocb_gp_lock); - wassleep = swait_active(&rdp->nocb_gp_wq); - if (!rdp->nocb_gp_sleep && !waslocked && !wassleep) - return; /* Nothing untoward. */ - - pr_info(" nocb GP activity on CB-only CPU!!! %c%c%c %c\n", - "lL"[waslocked], - "dD"[!!rdp->nocb_defer_wakeup], - "sS"[!!rdp->nocb_gp_sleep], - ".W"[wassleep]); -} - -#else /* #ifdef CONFIG_RCU_NOCB_CPU */ - -/* No ->nocb_lock to acquire. */ -static void rcu_nocb_lock(struct rcu_data *rdp) -{ -} - -/* No ->nocb_lock to release. */ -static void rcu_nocb_unlock(struct rcu_data *rdp) -{ -} - -/* No ->nocb_lock to release. */ -static void rcu_nocb_unlock_irqrestore(struct rcu_data *rdp, - unsigned long flags) -{ - local_irq_restore(flags); -} - -/* Lockdep check that ->cblist may be safely accessed. */ -static void rcu_lockdep_assert_cblist_protected(struct rcu_data *rdp) -{ - lockdep_assert_irqs_disabled(); -} - -static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq) -{ -} - -static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp) -{ - return NULL; -} - -static void rcu_init_one_nocb(struct rcu_node *rnp) -{ -} - -static bool rcu_nocb_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, - unsigned long j) -{ - return true; -} - -static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp, - bool *was_alldone, unsigned long flags) -{ - return false; -} - -static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_empty, - unsigned long flags) -{ - WARN_ON_ONCE(1); /* Should be dead code! */ -} - -static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp) -{ -} - -static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp, int level) -{ - return false; -} - -static bool do_nocb_deferred_wakeup(struct rcu_data *rdp) -{ - return false; -} - -static void rcu_spawn_cpu_nocb_kthread(int cpu) -{ -} - -static void __init rcu_spawn_nocb_kthreads(void) -{ -} - -static void show_rcu_nocb_state(struct rcu_data *rdp) -{ -} - -#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ - /* * Is this CPU a NO_HZ_FULL CPU that should ignore RCU so that the * grace-period kthread will do force_quiescent_state() processing? @@ -2982,17 +1498,17 @@ static void noinstr rcu_dynticks_task_exit(void) /* Turn on heavyweight RCU tasks trace readers on idle/user entry. */ static void rcu_dynticks_task_trace_enter(void) { -#ifdef CONFIG_TASKS_RCU_TRACE +#ifdef CONFIG_TASKS_TRACE_RCU if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB)) current->trc_reader_special.b.need_mb = true; -#endif /* #ifdef CONFIG_TASKS_RCU_TRACE */ +#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ } /* Turn off heavyweight RCU tasks trace readers on idle/user exit. */ static void rcu_dynticks_task_trace_exit(void) { -#ifdef CONFIG_TASKS_RCU_TRACE +#ifdef CONFIG_TASKS_TRACE_RCU if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB)) current->trc_reader_special.b.need_mb = false; -#endif /* #ifdef CONFIG_TASKS_RCU_TRACE */ +#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ } diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 6c76988cc019..677ee3d8671b 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -7,6 +7,8 @@ * Author: Paul E. McKenney <paulmck@linux.ibm.com> */ +#include <linux/kvm_para.h> + ////////////////////////////////////////////////////////////////////////////// // // Controlling CPU stall warnings, including delay calculation. @@ -117,17 +119,14 @@ static void panic_on_rcu_stall(void) } /** - * rcu_cpu_stall_reset - prevent further stall warnings in current grace period - * - * Set the stall-warning timeout way off into the future, thus preventing - * any RCU CPU stall-warning messages from appearing in the current set of - * RCU grace periods. + * rcu_cpu_stall_reset - restart stall-warning timeout for current grace period * * The caller must disable hard irqs. */ void rcu_cpu_stall_reset(void) { - WRITE_ONCE(rcu_state.jiffies_stall, jiffies + ULONG_MAX / 2); + WRITE_ONCE(rcu_state.jiffies_stall, + jiffies + rcu_jiffies_till_stall_check()); } ////////////////////////////////////////////////////////////////////////////// @@ -267,8 +266,10 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) struct task_struct *ts[8]; lockdep_assert_irqs_disabled(); - if (!rcu_preempt_blocked_readers_cgp(rnp)) + if (!rcu_preempt_blocked_readers_cgp(rnp)) { + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return 0; + } pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):", rnp->level, rnp->grplo, rnp->grphi); t = list_entry(rnp->gp_tasks->prev, @@ -280,8 +281,8 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) break; } raw_spin_unlock_irqrestore_rcu_node(rnp, flags); - for (i--; i; i--) { - t = ts[i]; + while (i) { + t = ts[--i]; if (!try_invoke_on_locked_down_task(t, check_slow_task, &rscr)) pr_cont(" P%d", t->pid); else @@ -350,7 +351,7 @@ static void rcu_dump_cpu_stacks(void) static void print_cpu_stall_fast_no_hz(char *cp, int cpu) { - struct rcu_data *rdp = &per_cpu(rcu_data, cpu); + struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); sprintf(cp, "last_accelerate: %04lx/%04lx dyntick_enabled: %d", rdp->last_accelerate & 0xffff, jiffies & 0xffff, @@ -464,9 +465,10 @@ static void rcu_check_gp_kthread_starvation(void) pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x ->cpu=%d\n", rcu_state.name, j, (long)rcu_seq_current(&rcu_state.gp_seq), - data_race(rcu_state.gp_flags), - gp_state_getname(rcu_state.gp_state), rcu_state.gp_state, - gpk ? gpk->__state : ~0, cpu); + data_race(READ_ONCE(rcu_state.gp_flags)), + gp_state_getname(rcu_state.gp_state), + data_race(READ_ONCE(rcu_state.gp_state)), + gpk ? data_race(READ_ONCE(gpk->__state)) : ~0, cpu); if (gpk) { pr_err("\tUnless %s kthread gets sufficient CPU time, OOM is now expected behavior.\n", rcu_state.name); pr_err("RCU grace-period kthread stack dump:\n"); @@ -509,7 +511,7 @@ static void rcu_check_gp_kthread_expired_fqs_timer(void) (long)rcu_seq_current(&rcu_state.gp_seq), data_race(rcu_state.gp_flags), gp_state_getname(RCU_GP_WAIT_FQS), RCU_GP_WAIT_FQS, - gpk->__state); + data_race(READ_ONCE(gpk->__state))); pr_err("\tPossible timer handling issue on cpu=%d timer-softirq=%u\n", cpu, kstat_softirqs_cpu(TIMER_SOFTIRQ, cpu)); } @@ -568,11 +570,11 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps) pr_err("INFO: Stall ended before state dump start\n"); } else { j = jiffies; - gpa = data_race(rcu_state.gp_activity); + gpa = data_race(READ_ONCE(rcu_state.gp_activity)); pr_err("All QSes seen, last %s kthread activity %ld (%ld-%ld), jiffies_till_next_fqs=%ld, root ->qsmask %#lx\n", rcu_state.name, j - gpa, j, gpa, - data_race(jiffies_till_next_fqs), - rcu_get_root()->qsmask); + data_race(READ_ONCE(jiffies_till_next_fqs)), + data_race(READ_ONCE(rcu_get_root()->qsmask))); } } /* Rewrite if needed in case of slow consoles. */ @@ -646,6 +648,7 @@ static void print_cpu_stall(unsigned long gps) static void check_cpu_stall(struct rcu_data *rdp) { + bool didstall = false; unsigned long gs1; unsigned long gs2; unsigned long gps; @@ -691,24 +694,46 @@ static void check_cpu_stall(struct rcu_data *rdp) ULONG_CMP_GE(gps, js)) return; /* No stall or GP completed since entering function. */ rnp = rdp->mynode; - jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; + jn = jiffies + ULONG_MAX / 2; if (rcu_gp_in_progress() && (READ_ONCE(rnp->qsmask) & rdp->grpmask) && cmpxchg(&rcu_state.jiffies_stall, js, jn) == js) { + /* + * If a virtual machine is stopped by the host it can look to + * the watchdog like an RCU stall. Check to see if the host + * stopped the vm. + */ + if (kvm_check_and_clear_guest_paused()) + return; + /* We haven't checked in, so go dump stack. */ print_cpu_stall(gps); if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) rcu_ftrace_dump(DUMP_ALL); + didstall = true; } else if (rcu_gp_in_progress() && ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY) && cmpxchg(&rcu_state.jiffies_stall, js, jn) == js) { + /* + * If a virtual machine is stopped by the host it can look to + * the watchdog like an RCU stall. Check to see if the host + * stopped the vm. + */ + if (kvm_check_and_clear_guest_paused()) + return; + /* They had a few time units to dump stack, so complain. */ print_other_cpu_stall(gs2, gps); if (READ_ONCE(rcu_cpu_stall_ftrace_dump)) rcu_ftrace_dump(DUMP_ALL); + didstall = true; + } + if (didstall && READ_ONCE(rcu_state.jiffies_stall) == jn) { + jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; + WRITE_ONCE(rcu_state.jiffies_stall, jn); } } @@ -742,7 +767,7 @@ bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) rcu_for_each_leaf_node(rnp) { if (!cpup) { - if (READ_ONCE(rnp->qsmask)) { + if (data_race(READ_ONCE(rnp->qsmask))) { return false; } else { if (READ_ONCE(rnp->gp_tasks)) @@ -791,32 +816,34 @@ void show_rcu_gp_kthreads(void) struct task_struct *t = READ_ONCE(rcu_state.gp_kthread); j = jiffies; - ja = j - data_race(rcu_state.gp_activity); - jr = j - data_race(rcu_state.gp_req_activity); - js = j - data_race(rcu_state.gp_start); - jw = j - data_race(rcu_state.gp_wake_time); + ja = j - data_race(READ_ONCE(rcu_state.gp_activity)); + jr = j - data_race(READ_ONCE(rcu_state.gp_req_activity)); + js = j - data_race(READ_ONCE(rcu_state.gp_start)); + jw = j - data_race(READ_ONCE(rcu_state.gp_wake_time)); pr_info("%s: wait state: %s(%d) ->state: %#x ->rt_priority %u delta ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags %#x\n", rcu_state.name, gp_state_getname(rcu_state.gp_state), - rcu_state.gp_state, t ? t->__state : 0x1ffff, t ? t->rt_priority : 0xffU, - js, ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq), - (long)data_race(rcu_state.gp_seq), - (long)data_race(rcu_get_root()->gp_seq_needed), - data_race(rcu_state.gp_max), - data_race(rcu_state.gp_flags)); + data_race(READ_ONCE(rcu_state.gp_state)), + t ? data_race(READ_ONCE(t->__state)) : 0x1ffff, t ? t->rt_priority : 0xffU, + js, ja, jr, jw, (long)data_race(READ_ONCE(rcu_state.gp_wake_seq)), + (long)data_race(READ_ONCE(rcu_state.gp_seq)), + (long)data_race(READ_ONCE(rcu_get_root()->gp_seq_needed)), + data_race(READ_ONCE(rcu_state.gp_max)), + data_race(READ_ONCE(rcu_state.gp_flags))); rcu_for_each_node_breadth_first(rnp) { if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq), READ_ONCE(rnp->gp_seq_needed)) && - !data_race(rnp->qsmask) && !data_race(rnp->boost_tasks) && - !data_race(rnp->exp_tasks) && !data_race(rnp->gp_tasks)) + !data_race(READ_ONCE(rnp->qsmask)) && !data_race(READ_ONCE(rnp->boost_tasks)) && + !data_race(READ_ONCE(rnp->exp_tasks)) && !data_race(READ_ONCE(rnp->gp_tasks))) continue; pr_info("\trcu_node %d:%d ->gp_seq %ld ->gp_seq_needed %ld ->qsmask %#lx %c%c%c%c ->n_boosts %ld\n", rnp->grplo, rnp->grphi, - (long)data_race(rnp->gp_seq), (long)data_race(rnp->gp_seq_needed), - data_race(rnp->qsmask), - ".b"[!!data_race(rnp->boost_kthread_task)], - ".B"[!!data_race(rnp->boost_tasks)], - ".E"[!!data_race(rnp->exp_tasks)], - ".G"[!!data_race(rnp->gp_tasks)], - data_race(rnp->n_boosts)); + (long)data_race(READ_ONCE(rnp->gp_seq)), + (long)data_race(READ_ONCE(rnp->gp_seq_needed)), + data_race(READ_ONCE(rnp->qsmask)), + ".b"[!!data_race(READ_ONCE(rnp->boost_kthread_task))], + ".B"[!!data_race(READ_ONCE(rnp->boost_tasks))], + ".E"[!!data_race(READ_ONCE(rnp->exp_tasks))], + ".G"[!!data_race(READ_ONCE(rnp->gp_tasks))], + data_race(READ_ONCE(rnp->n_boosts))); if (!rcu_is_leaf_node(rnp)) continue; for_each_leaf_node_possible_cpu(rnp, cpu) { @@ -826,12 +853,12 @@ void show_rcu_gp_kthreads(void) READ_ONCE(rdp->gp_seq_needed))) continue; pr_info("\tcpu %d ->gp_seq_needed %ld\n", - cpu, (long)data_race(rdp->gp_seq_needed)); + cpu, (long)data_race(READ_ONCE(rdp->gp_seq_needed))); } } for_each_possible_cpu(cpu) { rdp = per_cpu_ptr(&rcu_data, cpu); - cbs += data_race(rdp->n_cbs_invoked); + cbs += data_race(READ_ONCE(rdp->n_cbs_invoked)); if (rcu_segcblist_is_offloaded(&rdp->cblist)) show_rcu_nocb_state(rdp); } @@ -913,11 +940,11 @@ void rcu_fwd_progress_check(unsigned long j) if (rcu_gp_in_progress()) { pr_info("%s: GP age %lu jiffies\n", - __func__, jiffies - rcu_state.gp_start); + __func__, jiffies - data_race(READ_ONCE(rcu_state.gp_start))); show_rcu_gp_kthreads(); } else { pr_info("%s: Last GP end %lu jiffies ago\n", - __func__, jiffies - rcu_state.gp_end); + __func__, jiffies - data_race(READ_ONCE(rcu_state.gp_end))); preempt_disable(); rdp = this_cpu_ptr(&rcu_data); rcu_check_gp_start_stall(rdp->mynode, rdp, j); diff --git a/kernel/rseq.c b/kernel/rseq.c index 35f7bd0fced0..6d45ac3dae7f 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -282,9 +282,17 @@ void __rseq_handle_notify_resume(struct ksignal *ksig, struct pt_regs *regs) if (unlikely(t->flags & PF_EXITING)) return; - ret = rseq_ip_fixup(regs); - if (unlikely(ret < 0)) - goto error; + + /* + * regs is NULL if and only if the caller is in a syscall path. Skip + * fixup and leave rseq_cs as is so that rseq_sycall() will detect and + * kill a misbehaving userspace on debug kernels. + */ + if (regs) { + ret = rseq_ip_fixup(regs); + if (unlikely(ret < 0)) + goto error; + } if (unlikely(rseq_update_cpu_id(t))) goto error; return; diff --git a/kernel/scftorture.c b/kernel/scftorture.c index 29e8fc5d91a7..64a08288b1a6 100644 --- a/kernel/scftorture.c +++ b/kernel/scftorture.c @@ -64,6 +64,7 @@ torture_param(bool, use_cpus_read_lock, 0, "Use cpus_read_lock() to exclude CPU torture_param(int, verbose, 0, "Enable verbose debugging printk()s"); torture_param(int, weight_resched, -1, "Testing weight for resched_cpu() operations."); torture_param(int, weight_single, -1, "Testing weight for single-CPU no-wait operations."); +torture_param(int, weight_single_rpc, -1, "Testing weight for single-CPU RPC operations."); torture_param(int, weight_single_wait, -1, "Testing weight for single-CPU operations."); torture_param(int, weight_many, -1, "Testing weight for multi-CPU no-wait operations."); torture_param(int, weight_many_wait, -1, "Testing weight for multi-CPU operations."); @@ -86,6 +87,8 @@ struct scf_statistics { long long n_resched; long long n_single; long long n_single_ofl; + long long n_single_rpc; + long long n_single_rpc_ofl; long long n_single_wait; long long n_single_wait_ofl; long long n_many; @@ -101,14 +104,17 @@ static DEFINE_PER_CPU(long long, scf_invoked_count); // Data for random primitive selection #define SCF_PRIM_RESCHED 0 #define SCF_PRIM_SINGLE 1 -#define SCF_PRIM_MANY 2 -#define SCF_PRIM_ALL 3 -#define SCF_NPRIMS 7 // Need wait and no-wait versions of each, - // except for SCF_PRIM_RESCHED. +#define SCF_PRIM_SINGLE_RPC 2 +#define SCF_PRIM_MANY 3 +#define SCF_PRIM_ALL 4 +#define SCF_NPRIMS 8 // Need wait and no-wait versions of each, + // except for SCF_PRIM_RESCHED and + // SCF_PRIM_SINGLE_RPC. static char *scf_prim_name[] = { "resched_cpu", "smp_call_function_single", + "smp_call_function_single_rpc", "smp_call_function_many", "smp_call_function", }; @@ -128,6 +134,8 @@ struct scf_check { bool scfc_out; int scfc_cpu; // -1 for not _single(). bool scfc_wait; + bool scfc_rpc; + struct completion scfc_completion; }; // Use to wait for all threads to start. @@ -158,6 +166,7 @@ static void scf_torture_stats_print(void) scfs.n_resched += scf_stats_p[i].n_resched; scfs.n_single += scf_stats_p[i].n_single; scfs.n_single_ofl += scf_stats_p[i].n_single_ofl; + scfs.n_single_rpc += scf_stats_p[i].n_single_rpc; scfs.n_single_wait += scf_stats_p[i].n_single_wait; scfs.n_single_wait_ofl += scf_stats_p[i].n_single_wait_ofl; scfs.n_many += scf_stats_p[i].n_many; @@ -168,9 +177,10 @@ static void scf_torture_stats_print(void) if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) || atomic_read(&n_mb_out_errs) || atomic_read(&n_alloc_errs)) bangstr = "!!! "; - pr_alert("%s %sscf_invoked_count %s: %lld resched: %lld single: %lld/%lld single_ofl: %lld/%lld many: %lld/%lld all: %lld/%lld ", + pr_alert("%s %sscf_invoked_count %s: %lld resched: %lld single: %lld/%lld single_ofl: %lld/%lld single_rpc: %lld single_rpc_ofl: %lld many: %lld/%lld all: %lld/%lld ", SCFTORT_FLAG, bangstr, isdone ? "VER" : "ver", invoked_count, scfs.n_resched, scfs.n_single, scfs.n_single_wait, scfs.n_single_ofl, scfs.n_single_wait_ofl, + scfs.n_single_rpc, scfs.n_single_rpc_ofl, scfs.n_many, scfs.n_many_wait, scfs.n_all, scfs.n_all_wait); torture_onoff_stats(); pr_cont("ste: %d stnmie: %d stnmoe: %d staf: %d\n", atomic_read(&n_errs), @@ -282,10 +292,13 @@ static void scf_handler(void *scfc_in) out: if (unlikely(!scfcp)) return; - if (scfcp->scfc_wait) + if (scfcp->scfc_wait) { WRITE_ONCE(scfcp->scfc_out, true); - else + if (scfcp->scfc_rpc) + complete(&scfcp->scfc_completion); + } else { kfree(scfcp); + } } // As above, but check for correct CPU. @@ -319,6 +332,7 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra scfcp->scfc_cpu = -1; scfcp->scfc_wait = scfsp->scfs_wait; scfcp->scfc_out = false; + scfcp->scfc_rpc = false; } } switch (scfsp->scfs_prim) { @@ -350,6 +364,34 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra scfcp = NULL; } break; + case SCF_PRIM_SINGLE_RPC: + if (!scfcp) + break; + cpu = torture_random(trsp) % nr_cpu_ids; + scfp->n_single_rpc++; + scfcp->scfc_cpu = cpu; + scfcp->scfc_wait = true; + init_completion(&scfcp->scfc_completion); + scfcp->scfc_rpc = true; + barrier(); // Prevent race-reduction compiler optimizations. + scfcp->scfc_in = true; + ret = smp_call_function_single(cpu, scf_handler_1, (void *)scfcp, 0); + if (!ret) { + if (use_cpus_read_lock) + cpus_read_unlock(); + else + preempt_enable(); + wait_for_completion(&scfcp->scfc_completion); + if (use_cpus_read_lock) + cpus_read_lock(); + else + preempt_disable(); + } else { + scfp->n_single_rpc_ofl++; + kfree(scfcp); + scfcp = NULL; + } + break; case SCF_PRIM_MANY: if (scfsp->scfs_wait) scfp->n_many_wait++; @@ -379,10 +421,12 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra } if (scfcp && scfsp->scfs_wait) { if (WARN_ON_ONCE((num_online_cpus() > 1 || scfsp->scfs_prim == SCF_PRIM_SINGLE) && - !scfcp->scfc_out)) + !scfcp->scfc_out)) { + pr_warn("%s: Memory-ordering failure, scfs_prim: %d.\n", __func__, scfsp->scfs_prim); atomic_inc(&n_mb_out_errs); // Leak rather than trash! - else + } else { kfree(scfcp); + } barrier(); // Prevent race-reduction compiler optimizations. } if (use_cpus_read_lock) @@ -453,8 +497,8 @@ static void scftorture_print_module_parms(const char *tag) { pr_alert(SCFTORT_FLAG - "--- %s: verbose=%d holdoff=%d longwait=%d nthreads=%d onoff_holdoff=%d onoff_interval=%d shutdown_secs=%d stat_interval=%d stutter=%d use_cpus_read_lock=%d, weight_resched=%d, weight_single=%d, weight_single_wait=%d, weight_many=%d, weight_many_wait=%d, weight_all=%d, weight_all_wait=%d\n", tag, - verbose, holdoff, longwait, nthreads, onoff_holdoff, onoff_interval, shutdown, stat_interval, stutter, use_cpus_read_lock, weight_resched, weight_single, weight_single_wait, weight_many, weight_many_wait, weight_all, weight_all_wait); + "--- %s: verbose=%d holdoff=%d longwait=%d nthreads=%d onoff_holdoff=%d onoff_interval=%d shutdown_secs=%d stat_interval=%d stutter=%d use_cpus_read_lock=%d, weight_resched=%d, weight_single=%d, weight_single_rpc=%d, weight_single_wait=%d, weight_many=%d, weight_many_wait=%d, weight_all=%d, weight_all_wait=%d\n", tag, + verbose, holdoff, longwait, nthreads, onoff_holdoff, onoff_interval, shutdown, stat_interval, stutter, use_cpus_read_lock, weight_resched, weight_single, weight_single_rpc, weight_single_wait, weight_many, weight_many_wait, weight_all, weight_all_wait); } static void scf_cleanup_handler(void *unused) @@ -469,7 +513,7 @@ static void scf_torture_cleanup(void) return; WRITE_ONCE(scfdone, true); - if (nthreads) + if (nthreads && scf_stats_p) for (i = 0; i < nthreads; i++) torture_stop_kthread("scftorture_invoker", scf_stats_p[i].task); else @@ -497,6 +541,7 @@ static int __init scf_torture_init(void) int firsterr = 0; unsigned long weight_resched1 = weight_resched; unsigned long weight_single1 = weight_single; + unsigned long weight_single_rpc1 = weight_single_rpc; unsigned long weight_single_wait1 = weight_single_wait; unsigned long weight_many1 = weight_many; unsigned long weight_many_wait1 = weight_many_wait; @@ -508,11 +553,13 @@ static int __init scf_torture_init(void) scftorture_print_module_parms("Start of test"); - if (weight_resched == -1 && weight_single == -1 && weight_single_wait == -1 && + if (weight_resched == -1 && + weight_single == -1 && weight_single_rpc == -1 && weight_single_wait == -1 && weight_many == -1 && weight_many_wait == -1 && weight_all == -1 && weight_all_wait == -1) { weight_resched1 = 2 * nr_cpu_ids; weight_single1 = 2 * nr_cpu_ids; + weight_single_rpc1 = 2 * nr_cpu_ids; weight_single_wait1 = 2 * nr_cpu_ids; weight_many1 = 2; weight_many_wait1 = 2; @@ -523,6 +570,8 @@ static int __init scf_torture_init(void) weight_resched1 = 0; if (weight_single == -1) weight_single1 = 0; + if (weight_single_rpc == -1) + weight_single_rpc1 = 0; if (weight_single_wait == -1) weight_single_wait1 = 0; if (weight_many == -1) @@ -534,7 +583,7 @@ static int __init scf_torture_init(void) if (weight_all_wait == -1) weight_all_wait1 = 0; } - if (weight_single1 == 0 && weight_single_wait1 == 0 && + if (weight_single1 == 0 && weight_single_rpc1 == 0 && weight_single_wait1 == 0 && weight_many1 == 0 && weight_many_wait1 == 0 && weight_all1 == 0 && weight_all_wait1 == 0) { VERBOSE_SCFTORTOUT_ERRSTRING("all zero weights makes no sense"); @@ -546,6 +595,7 @@ static int __init scf_torture_init(void) else if (weight_resched1) VERBOSE_SCFTORTOUT_ERRSTRING("built as module, weight_resched ignored"); scf_sel_add(weight_single1, SCF_PRIM_SINGLE, false); + scf_sel_add(weight_single_rpc1, SCF_PRIM_SINGLE_RPC, true); scf_sel_add(weight_single_wait1, SCF_PRIM_SINGLE, true); scf_sel_add(weight_many1, SCF_PRIM_MANY, false); scf_sel_add(weight_many_wait1, SCF_PRIM_MANY, true); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 20ffcc044134..59bea523c84b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -13,7 +13,7 @@ #include "sched.h" #include <linux/nospec.h> - +#include <linux/blkdev.h> #include <linux/kcov.h> #include <linux/scs.h> @@ -237,9 +237,30 @@ static DEFINE_MUTEX(sched_core_mutex); static atomic_t sched_core_count; static struct cpumask sched_core_mask; +static void sched_core_lock(int cpu, unsigned long *flags) +{ + const struct cpumask *smt_mask = cpu_smt_mask(cpu); + int t, i = 0; + + local_irq_save(*flags); + for_each_cpu(t, smt_mask) + raw_spin_lock_nested(&cpu_rq(t)->__lock, i++); +} + +static void sched_core_unlock(int cpu, unsigned long *flags) +{ + const struct cpumask *smt_mask = cpu_smt_mask(cpu); + int t; + + for_each_cpu(t, smt_mask) + raw_spin_unlock(&cpu_rq(t)->__lock); + local_irq_restore(*flags); +} + static void __sched_core_flip(bool enabled) { - int cpu, t, i; + unsigned long flags; + int cpu, t; cpus_read_lock(); @@ -250,19 +271,12 @@ static void __sched_core_flip(bool enabled) for_each_cpu(cpu, &sched_core_mask) { const struct cpumask *smt_mask = cpu_smt_mask(cpu); - i = 0; - local_irq_disable(); - for_each_cpu(t, smt_mask) { - /* supports up to SMT8 */ - raw_spin_lock_nested(&cpu_rq(t)->__lock, i++); - } + sched_core_lock(cpu, &flags); for_each_cpu(t, smt_mask) cpu_rq(t)->core_enabled = enabled; - for_each_cpu(t, smt_mask) - raw_spin_unlock(&cpu_rq(t)->__lock); - local_irq_enable(); + sched_core_unlock(cpu, &flags); cpumask_andnot(&sched_core_mask, &sched_core_mask, smt_mask); } @@ -993,6 +1007,7 @@ int get_nohz_timer_target(void) { int i, cpu = smp_processor_id(), default_cpu = -1; struct sched_domain *sd; + const struct cpumask *hk_mask; if (housekeeping_cpu(cpu, HK_FLAG_TIMER)) { if (!idle_cpu(cpu)) @@ -1000,10 +1015,11 @@ int get_nohz_timer_target(void) default_cpu = cpu; } + hk_mask = housekeeping_cpumask(HK_FLAG_TIMER); + rcu_read_lock(); for_each_domain(cpu, sd) { - for_each_cpu_and(i, sched_domain_span(sd), - housekeeping_cpumask(HK_FLAG_TIMER)) { + for_each_cpu_and(i, sched_domain_span(sd), hk_mask) { if (cpu == i) continue; @@ -1619,6 +1635,23 @@ static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) uclamp_rq_dec_id(rq, p, clamp_id); } +static inline void uclamp_rq_reinc_id(struct rq *rq, struct task_struct *p, + enum uclamp_id clamp_id) +{ + if (!p->uclamp[clamp_id].active) + return; + + uclamp_rq_dec_id(rq, p, clamp_id); + uclamp_rq_inc_id(rq, p, clamp_id); + + /* + * Make sure to clear the idle flag if we've transiently reached 0 + * active tasks on rq. + */ + if (clamp_id == UCLAMP_MAX && (rq->uclamp_flags & UCLAMP_FLAG_IDLE)) + rq->uclamp_flags &= ~UCLAMP_FLAG_IDLE; +} + static inline void uclamp_update_active(struct task_struct *p) { @@ -1642,12 +1675,8 @@ uclamp_update_active(struct task_struct *p) * affecting a valid clamp bucket, the next time it's enqueued, * it will already see the updated clamp bucket value. */ - for_each_clamp_id(clamp_id) { - if (p->uclamp[clamp_id].active) { - uclamp_rq_dec_id(rq, p, clamp_id); - uclamp_rq_inc_id(rq, p, clamp_id); - } - } + for_each_clamp_id(clamp_id) + uclamp_rq_reinc_id(rq, p, clamp_id); task_rq_unlock(rq, p, &rf); } @@ -2161,7 +2190,7 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu) /* Non kernel threads are not allowed during either online or offline. */ if (!(p->flags & PF_KTHREAD)) - return cpu_active(cpu); + return cpu_active(cpu) && task_cpu_possible(cpu, p); /* KTHREAD_IS_PER_CPU is always allowed. */ if (kthread_is_per_cpu(p)) @@ -2468,6 +2497,34 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) __do_set_cpus_allowed(p, new_mask, 0); } +int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, + int node) +{ + if (!src->user_cpus_ptr) + return 0; + + dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node); + if (!dst->user_cpus_ptr) + return -ENOMEM; + + cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); + return 0; +} + +static inline struct cpumask *clear_user_cpus_ptr(struct task_struct *p) +{ + struct cpumask *user_mask = NULL; + + swap(p->user_cpus_ptr, user_mask); + + return user_mask; +} + +void release_user_cpus_ptr(struct task_struct *p) +{ + kfree(clear_user_cpus_ptr(p)); +} + /* * This function is wildly self concurrent; here be dragons. * @@ -2685,28 +2742,26 @@ static int affine_move_task(struct rq *rq, struct task_struct *p, struct rq_flag } /* - * Change a given task's CPU affinity. Migrate the thread to a - * proper CPU and schedule it away if the CPU it's executing on - * is removed from the allowed bitmask. - * - * NOTE: the caller must have a valid reference to the task, the - * task must not exit() & deallocate itself prematurely. The - * call is not atomic; no spinlocks may be held. + * Called with both p->pi_lock and rq->lock held; drops both before returning. */ -static int __set_cpus_allowed_ptr(struct task_struct *p, - const struct cpumask *new_mask, - u32 flags) +static int __set_cpus_allowed_ptr_locked(struct task_struct *p, + const struct cpumask *new_mask, + u32 flags, + struct rq *rq, + struct rq_flags *rf) + __releases(rq->lock) + __releases(p->pi_lock) { + const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); const struct cpumask *cpu_valid_mask = cpu_active_mask; + bool kthread = p->flags & PF_KTHREAD; + struct cpumask *user_mask = NULL; unsigned int dest_cpu; - struct rq_flags rf; - struct rq *rq; int ret = 0; - rq = task_rq_lock(p, &rf); update_rq_clock(rq); - if (p->flags & PF_KTHREAD || is_migration_disabled(p)) { + if (kthread || is_migration_disabled(p)) { /* * Kernel threads are allowed on online && !active CPUs, * however, during cpu-hot-unplug, even these might get pushed @@ -2720,6 +2775,11 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, cpu_valid_mask = cpu_online_mask; } + if (!kthread && !cpumask_subset(new_mask, cpu_allowed_mask)) { + ret = -EINVAL; + goto out; + } + /* * Must re-check here, to close a race against __kthread_bind(), * sched_setaffinity() is not guaranteed to observe the flag. @@ -2754,20 +2814,178 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, __do_set_cpus_allowed(p, new_mask, flags); - return affine_move_task(rq, p, &rf, dest_cpu, flags); + if (flags & SCA_USER) + user_mask = clear_user_cpus_ptr(p); + + ret = affine_move_task(rq, p, rf, dest_cpu, flags); + + kfree(user_mask); + + return ret; out: - task_rq_unlock(rq, p, &rf); + task_rq_unlock(rq, p, rf); return ret; } +/* + * Change a given task's CPU affinity. Migrate the thread to a + * proper CPU and schedule it away if the CPU it's executing on + * is removed from the allowed bitmask. + * + * NOTE: the caller must have a valid reference to the task, the + * task must not exit() & deallocate itself prematurely. The + * call is not atomic; no spinlocks may be held. + */ +static int __set_cpus_allowed_ptr(struct task_struct *p, + const struct cpumask *new_mask, u32 flags) +{ + struct rq_flags rf; + struct rq *rq; + + rq = task_rq_lock(p, &rf); + return __set_cpus_allowed_ptr_locked(p, new_mask, flags, rq, &rf); +} + int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) { return __set_cpus_allowed_ptr(p, new_mask, 0); } EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); +/* + * Change a given task's CPU affinity to the intersection of its current + * affinity mask and @subset_mask, writing the resulting mask to @new_mask + * and pointing @p->user_cpus_ptr to a copy of the old mask. + * If the resulting mask is empty, leave the affinity unchanged and return + * -EINVAL. + */ +static int restrict_cpus_allowed_ptr(struct task_struct *p, + struct cpumask *new_mask, + const struct cpumask *subset_mask) +{ + struct cpumask *user_mask = NULL; + struct rq_flags rf; + struct rq *rq; + int err; + + if (!p->user_cpus_ptr) { + user_mask = kmalloc(cpumask_size(), GFP_KERNEL); + if (!user_mask) + return -ENOMEM; + } + + rq = task_rq_lock(p, &rf); + + /* + * Forcefully restricting the affinity of a deadline task is + * likely to cause problems, so fail and noisily override the + * mask entirely. + */ + if (task_has_dl_policy(p) && dl_bandwidth_enabled()) { + err = -EPERM; + goto err_unlock; + } + + if (!cpumask_and(new_mask, &p->cpus_mask, subset_mask)) { + err = -EINVAL; + goto err_unlock; + } + + /* + * We're about to butcher the task affinity, so keep track of what + * the user asked for in case we're able to restore it later on. + */ + if (user_mask) { + cpumask_copy(user_mask, p->cpus_ptr); + p->user_cpus_ptr = user_mask; + } + + return __set_cpus_allowed_ptr_locked(p, new_mask, 0, rq, &rf); + +err_unlock: + task_rq_unlock(rq, p, &rf); + kfree(user_mask); + return err; +} + +/* + * Restrict the CPU affinity of task @p so that it is a subset of + * task_cpu_possible_mask() and point @p->user_cpu_ptr to a copy of the + * old affinity mask. If the resulting mask is empty, we warn and walk + * up the cpuset hierarchy until we find a suitable mask. + */ +void force_compatible_cpus_allowed_ptr(struct task_struct *p) +{ + cpumask_var_t new_mask; + const struct cpumask *override_mask = task_cpu_possible_mask(p); + + alloc_cpumask_var(&new_mask, GFP_KERNEL); + + /* + * __migrate_task() can fail silently in the face of concurrent + * offlining of the chosen destination CPU, so take the hotplug + * lock to ensure that the migration succeeds. + */ + cpus_read_lock(); + if (!cpumask_available(new_mask)) + goto out_set_mask; + + if (!restrict_cpus_allowed_ptr(p, new_mask, override_mask)) + goto out_free_mask; + + /* + * We failed to find a valid subset of the affinity mask for the + * task, so override it based on its cpuset hierarchy. + */ + cpuset_cpus_allowed(p, new_mask); + override_mask = new_mask; + +out_set_mask: + if (printk_ratelimit()) { + printk_deferred("Overriding affinity for process %d (%s) to CPUs %*pbl\n", + task_pid_nr(p), p->comm, + cpumask_pr_args(override_mask)); + } + + WARN_ON(set_cpus_allowed_ptr(p, override_mask)); +out_free_mask: + cpus_read_unlock(); + free_cpumask_var(new_mask); +} + +static int +__sched_setaffinity(struct task_struct *p, const struct cpumask *mask); + +/* + * Restore the affinity of a task @p which was previously restricted by a + * call to force_compatible_cpus_allowed_ptr(). This will clear (and free) + * @p->user_cpus_ptr. + * + * It is the caller's responsibility to serialise this with any calls to + * force_compatible_cpus_allowed_ptr(@p). + */ +void relax_compatible_cpus_allowed_ptr(struct task_struct *p) +{ + struct cpumask *user_mask = p->user_cpus_ptr; + unsigned long flags; + + /* + * Try to restore the old affinity mask. If this fails, then + * we free the mask explicitly to avoid it being inherited across + * a subsequent fork(). + */ + if (!user_mask || !__sched_setaffinity(p, user_mask)) + return; + + raw_spin_lock_irqsave(&p->pi_lock, flags); + user_mask = clear_user_cpus_ptr(p); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); + + kfree(user_mask); +} + void set_task_cpu(struct task_struct *p, unsigned int new_cpu) { #ifdef CONFIG_SCHED_DEBUG @@ -3112,9 +3330,7 @@ static int select_fallback_rq(int cpu, struct task_struct *p) /* Look for allowed, online CPU in same node. */ for_each_cpu(dest_cpu, nodemask) { - if (!cpu_active(dest_cpu)) - continue; - if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) + if (is_cpu_allowed(p, dest_cpu)) return dest_cpu; } } @@ -3131,8 +3347,7 @@ static int select_fallback_rq(int cpu, struct task_struct *p) /* No more Mr. Nice Guy. */ switch (state) { case cpuset: - if (IS_ENABLED(CONFIG_CPUSETS)) { - cpuset_cpus_allowed_fallback(p); + if (cpuset_cpus_allowed_fallback(p)) { state = possible; break; } @@ -3144,10 +3359,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p) * * More yuck to audit. */ - do_set_cpus_allowed(p, cpu_possible_mask); + do_set_cpus_allowed(p, task_cpu_possible_mask(p)); state = fail; break; - case fail: BUG(); break; @@ -3562,6 +3776,55 @@ static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) } /* + * Invoked from try_to_wake_up() to check whether the task can be woken up. + * + * The caller holds p::pi_lock if p != current or has preemption + * disabled when p == current. + * + * The rules of PREEMPT_RT saved_state: + * + * The related locking code always holds p::pi_lock when updating + * p::saved_state, which means the code is fully serialized in both cases. + * + * The lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. No other + * bits set. This allows to distinguish all wakeup scenarios. + */ +static __always_inline +bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) +{ + if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) { + WARN_ON_ONCE((state & TASK_RTLOCK_WAIT) && + state != TASK_RTLOCK_WAIT); + } + + if (READ_ONCE(p->__state) & state) { + *success = 1; + return true; + } + +#ifdef CONFIG_PREEMPT_RT + /* + * Saved state preserves the task state across blocking on + * an RT lock. If the state matches, set p::saved_state to + * TASK_RUNNING, but do not wake the task because it waits + * for a lock wakeup. Also indicate success because from + * the regular waker's point of view this has succeeded. + * + * After acquiring the lock the task will restore p::__state + * from p::saved_state which ensures that the regular + * wakeup is not lost. The restore will also set + * p::saved_state to TASK_RUNNING so any further tests will + * not result in false positives vs. @success + */ + if (p->saved_state & state) { + p->saved_state = TASK_RUNNING; + *success = 1; + } +#endif + return false; +} + +/* * Notes on Program-Order guarantees on SMP systems. * * MIGRATION @@ -3700,10 +3963,9 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) * - we're serialized against set_special_state() by virtue of * it disabling IRQs (this allows not taking ->pi_lock). */ - if (!(READ_ONCE(p->__state) & state)) + if (!ttwu_state_match(p, state, &success)) goto out; - success = 1; trace_sched_waking(p); WRITE_ONCE(p->__state, TASK_RUNNING); trace_sched_wakeup(p); @@ -3718,14 +3980,11 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) */ raw_spin_lock_irqsave(&p->pi_lock, flags); smp_mb__after_spinlock(); - if (!(READ_ONCE(p->__state) & state)) + if (!ttwu_state_match(p, state, &success)) goto unlock; trace_sched_waking(p); - /* We're going to change ->state: */ - success = 1; - /* * Ensure we load p->on_rq _after_ p->state, otherwise it would * be possible to, falsely, observe p->on_rq == 0 and get stuck @@ -5660,11 +5919,9 @@ static bool try_steal_cookie(int this, int that) if (p->core_occupation > dst->idle->core_occupation) goto next; - p->on_rq = TASK_ON_RQ_MIGRATING; deactivate_task(src, p, 0); set_task_cpu(p, this); activate_task(dst, p, 0); - p->on_rq = TASK_ON_RQ_QUEUED; resched_curr(dst); @@ -5736,35 +5993,109 @@ void queue_core_balance(struct rq *rq) queue_balance_callback(rq, &per_cpu(core_balance_head, rq->cpu), sched_core_balance); } -static inline void sched_core_cpu_starting(unsigned int cpu) +static void sched_core_cpu_starting(unsigned int cpu) { const struct cpumask *smt_mask = cpu_smt_mask(cpu); - struct rq *rq, *core_rq = NULL; - int i; + struct rq *rq = cpu_rq(cpu), *core_rq = NULL; + unsigned long flags; + int t; - core_rq = cpu_rq(cpu)->core; + sched_core_lock(cpu, &flags); - if (!core_rq) { - for_each_cpu(i, smt_mask) { - rq = cpu_rq(i); - if (rq->core && rq->core == rq) - core_rq = rq; + WARN_ON_ONCE(rq->core != rq); + + /* if we're the first, we'll be our own leader */ + if (cpumask_weight(smt_mask) == 1) + goto unlock; + + /* find the leader */ + for_each_cpu(t, smt_mask) { + if (t == cpu) + continue; + rq = cpu_rq(t); + if (rq->core == rq) { + core_rq = rq; + break; } + } - if (!core_rq) - core_rq = cpu_rq(cpu); + if (WARN_ON_ONCE(!core_rq)) /* whoopsie */ + goto unlock; - for_each_cpu(i, smt_mask) { - rq = cpu_rq(i); + /* install and validate core_rq */ + for_each_cpu(t, smt_mask) { + rq = cpu_rq(t); - WARN_ON_ONCE(rq->core && rq->core != core_rq); + if (t == cpu) rq->core = core_rq; - } + + WARN_ON_ONCE(rq->core != core_rq); + } + +unlock: + sched_core_unlock(cpu, &flags); +} + +static void sched_core_cpu_deactivate(unsigned int cpu) +{ + const struct cpumask *smt_mask = cpu_smt_mask(cpu); + struct rq *rq = cpu_rq(cpu), *core_rq = NULL; + unsigned long flags; + int t; + + sched_core_lock(cpu, &flags); + + /* if we're the last man standing, nothing to do */ + if (cpumask_weight(smt_mask) == 1) { + WARN_ON_ONCE(rq->core != rq); + goto unlock; + } + + /* if we're not the leader, nothing to do */ + if (rq->core != rq) + goto unlock; + + /* find a new leader */ + for_each_cpu(t, smt_mask) { + if (t == cpu) + continue; + core_rq = cpu_rq(t); + break; } + + if (WARN_ON_ONCE(!core_rq)) /* impossible */ + goto unlock; + + /* copy the shared state to the new leader */ + core_rq->core_task_seq = rq->core_task_seq; + core_rq->core_pick_seq = rq->core_pick_seq; + core_rq->core_cookie = rq->core_cookie; + core_rq->core_forceidle = rq->core_forceidle; + core_rq->core_forceidle_seq = rq->core_forceidle_seq; + + /* install new leader */ + for_each_cpu(t, smt_mask) { + rq = cpu_rq(t); + rq->core = core_rq; + } + +unlock: + sched_core_unlock(cpu, &flags); } + +static inline void sched_core_cpu_dying(unsigned int cpu) +{ + struct rq *rq = cpu_rq(cpu); + + if (rq->core != rq) + rq->core = rq; +} + #else /* !CONFIG_SCHED_CORE */ static inline void sched_core_cpu_starting(unsigned int cpu) {} +static inline void sched_core_cpu_deactivate(unsigned int cpu) {} +static inline void sched_core_cpu_dying(unsigned int cpu) {} static struct task_struct * pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) @@ -5775,6 +6106,24 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) #endif /* CONFIG_SCHED_CORE */ /* + * Constants for the sched_mode argument of __schedule(). + * + * The mode argument allows RT enabled kernels to differentiate a + * preemption from blocking on an 'sleeping' spin/rwlock. Note that + * SM_MASK_PREEMPT for !RT has all bits set, which allows the compiler to + * optimize the AND operation out and just check for zero. + */ +#define SM_NONE 0x0 +#define SM_PREEMPT 0x1 +#define SM_RTLOCK_WAIT 0x2 + +#ifndef CONFIG_PREEMPT_RT +# define SM_MASK_PREEMPT (~0U) +#else +# define SM_MASK_PREEMPT SM_PREEMPT +#endif + +/* * __schedule() is the main scheduler function. * * The main means of driving the scheduler and thus entering this function are: @@ -5813,7 +6162,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) * * WARNING: must be called with preemption disabled! */ -static void __sched notrace __schedule(bool preempt) +static void __sched notrace __schedule(unsigned int sched_mode) { struct task_struct *prev, *next; unsigned long *switch_count; @@ -5826,13 +6175,13 @@ static void __sched notrace __schedule(bool preempt) rq = cpu_rq(cpu); prev = rq->curr; - schedule_debug(prev, preempt); + schedule_debug(prev, !!sched_mode); if (sched_feat(HRTICK) || sched_feat(HRTICK_DL)) hrtick_clear(rq); local_irq_disable(); - rcu_note_context_switch(preempt); + rcu_note_context_switch(!!sched_mode); /* * Make sure that signal_pending_state()->signal_pending() below @@ -5866,7 +6215,7 @@ static void __sched notrace __schedule(bool preempt) * - ptrace_{,un}freeze_traced() can change ->state underneath us. */ prev_state = READ_ONCE(prev->__state); - if (!preempt && prev_state) { + if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { if (signal_pending_state(prev_state, prev)) { WRITE_ONCE(prev->__state, TASK_RUNNING); } else { @@ -5932,7 +6281,7 @@ static void __sched notrace __schedule(bool preempt) migrate_disable_switch(rq, prev); psi_sched_switch(prev, next, !task_on_rq_queued(prev)); - trace_sched_switch(preempt, prev, next); + trace_sched_switch(sched_mode & SM_MASK_PREEMPT, prev, next); /* Also unlocks the rq: */ rq = context_switch(rq, prev, next, &rf); @@ -5953,7 +6302,7 @@ void __noreturn do_task_dead(void) /* Tell freezer to ignore us: */ current->flags |= PF_NOFREEZE; - __schedule(false); + __schedule(SM_NONE); BUG(); /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */ @@ -5994,7 +6343,7 @@ static inline void sched_submit_work(struct task_struct *tsk) * make sure to submit it to avoid deadlocks. */ if (blk_needs_flush_plug(tsk)) - blk_schedule_flush_plug(tsk); + blk_flush_plug(tsk->plug, true); } static void sched_update_worker(struct task_struct *tsk) @@ -6014,7 +6363,7 @@ asmlinkage __visible void __sched schedule(void) sched_submit_work(tsk); do { preempt_disable(); - __schedule(false); + __schedule(SM_NONE); sched_preempt_enable_no_resched(); } while (need_resched()); sched_update_worker(tsk); @@ -6042,7 +6391,7 @@ void __sched schedule_idle(void) */ WARN_ON_ONCE(current->__state); do { - __schedule(false); + __schedule(SM_NONE); } while (need_resched()); } @@ -6077,6 +6426,18 @@ void __sched schedule_preempt_disabled(void) preempt_disable(); } +#ifdef CONFIG_PREEMPT_RT +void __sched notrace schedule_rtlock(void) +{ + do { + preempt_disable(); + __schedule(SM_RTLOCK_WAIT); + sched_preempt_enable_no_resched(); + } while (need_resched()); +} +NOKPROBE_SYMBOL(schedule_rtlock); +#endif + static void __sched notrace preempt_schedule_common(void) { do { @@ -6095,7 +6456,7 @@ static void __sched notrace preempt_schedule_common(void) */ preempt_disable_notrace(); preempt_latency_start(1); - __schedule(true); + __schedule(SM_PREEMPT); preempt_latency_stop(1); preempt_enable_no_resched_notrace(); @@ -6174,7 +6535,7 @@ asmlinkage __visible void __sched notrace preempt_schedule_notrace(void) * an infinite recursion. */ prev_ctx = exception_enter(); - __schedule(true); + __schedule(SM_PREEMPT); exception_exit(prev_ctx); preempt_latency_stop(1); @@ -6323,7 +6684,7 @@ asmlinkage __visible void __sched preempt_schedule_irq(void) do { preempt_disable(); local_irq_enable(); - __schedule(true); + __schedule(SM_PREEMPT); local_irq_disable(); sched_preempt_enable_no_resched(); } while (need_resched()); @@ -7300,6 +7661,16 @@ err_size: return -E2BIG; } +static void get_params(struct task_struct *p, struct sched_attr *attr) +{ + if (task_has_dl_policy(p)) + __getparam_dl(p, attr); + else if (task_has_rt_policy(p)) + attr->sched_priority = p->rt_priority; + else + attr->sched_nice = task_nice(p); +} + /** * sys_sched_setscheduler - set/change the scheduler policy and RT priority * @pid: the pid in question. @@ -7361,6 +7732,8 @@ SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, rcu_read_unlock(); if (likely(p)) { + if (attr.sched_flags & SCHED_FLAG_KEEP_PARAMS) + get_params(p, &attr); retval = sched_setattr(p, &attr); put_task_struct(p); } @@ -7509,12 +7882,8 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, kattr.sched_policy = p->policy; if (p->sched_reset_on_fork) kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; - if (task_has_dl_policy(p)) - __getparam_dl(p, &kattr); - else if (task_has_rt_policy(p)) - kattr.sched_priority = p->rt_priority; - else - kattr.sched_nice = task_nice(p); + get_params(p, &kattr); + kattr.sched_flags &= SCHED_FLAG_ALL; #ifdef CONFIG_UCLAMP_TASK /* @@ -7535,9 +7904,76 @@ out_unlock: return retval; } -long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) +#ifdef CONFIG_SMP +int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) +{ + int ret = 0; + + /* + * If the task isn't a deadline task or admission control is + * disabled then we don't care about affinity changes. + */ + if (!task_has_dl_policy(p) || !dl_bandwidth_enabled()) + return 0; + + /* + * Since bandwidth control happens on root_domain basis, + * if admission test is enabled, we only admit -deadline + * tasks allowed to run on all the CPUs in the task's + * root_domain. + */ + rcu_read_lock(); + if (!cpumask_subset(task_rq(p)->rd->span, mask)) + ret = -EBUSY; + rcu_read_unlock(); + return ret; +} +#endif + +static int +__sched_setaffinity(struct task_struct *p, const struct cpumask *mask) { + int retval; cpumask_var_t cpus_allowed, new_mask; + + if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) + return -ENOMEM; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_free_cpus_allowed; + } + + cpuset_cpus_allowed(p, cpus_allowed); + cpumask_and(new_mask, mask, cpus_allowed); + + retval = dl_task_check_affinity(p, new_mask); + if (retval) + goto out_free_new_mask; +again: + retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK | SCA_USER); + if (retval) + goto out_free_new_mask; + + cpuset_cpus_allowed(p, cpus_allowed); + if (!cpumask_subset(new_mask, cpus_allowed)) { + /* + * We must have raced with a concurrent cpuset update. + * Just reset the cpumask to the cpuset's cpus_allowed. + */ + cpumask_copy(new_mask, cpus_allowed); + goto again; + } + +out_free_new_mask: + free_cpumask_var(new_mask); +out_free_cpus_allowed: + free_cpumask_var(cpus_allowed); + return retval; +} + +long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) +{ struct task_struct *p; int retval; @@ -7557,68 +7993,22 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) retval = -EINVAL; goto out_put_task; } - if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { - retval = -ENOMEM; - goto out_put_task; - } - if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { - retval = -ENOMEM; - goto out_free_cpus_allowed; - } - retval = -EPERM; + if (!check_same_owner(p)) { rcu_read_lock(); if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { rcu_read_unlock(); - goto out_free_new_mask; + retval = -EPERM; + goto out_put_task; } rcu_read_unlock(); } retval = security_task_setscheduler(p); if (retval) - goto out_free_new_mask; - - - cpuset_cpus_allowed(p, cpus_allowed); - cpumask_and(new_mask, in_mask, cpus_allowed); - - /* - * Since bandwidth control happens on root_domain basis, - * if admission test is enabled, we only admit -deadline - * tasks allowed to run on all the CPUs in the task's - * root_domain. - */ -#ifdef CONFIG_SMP - if (task_has_dl_policy(p) && dl_bandwidth_enabled()) { - rcu_read_lock(); - if (!cpumask_subset(task_rq(p)->rd->span, new_mask)) { - retval = -EBUSY; - rcu_read_unlock(); - goto out_free_new_mask; - } - rcu_read_unlock(); - } -#endif -again: - retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK); + goto out_put_task; - if (!retval) { - cpuset_cpus_allowed(p, cpus_allowed); - if (!cpumask_subset(new_mask, cpus_allowed)) { - /* - * We must have raced with a concurrent cpuset - * update. Just reset the cpus_allowed to the - * cpuset's cpus_allowed - */ - cpumask_copy(new_mask, cpus_allowed); - goto again; - } - } -out_free_new_mask: - free_cpumask_var(new_mask); -out_free_cpus_allowed: - free_cpumask_var(cpus_allowed); + retval = __sched_setaffinity(p, in_mask); out_put_task: put_task_struct(p); return retval; @@ -7761,6 +8151,17 @@ int __sched __cond_resched(void) preempt_schedule_common(); return 1; } + /* + * In preemptible kernels, ->rcu_read_lock_nesting tells the tick + * whether the current CPU is in an RCU read-side critical section, + * so the tick can report quiescent states even for CPUs looping + * in kernel context. In contrast, in non-preemptible kernels, + * RCU readers leave no in-memory hints, which means that CPU-bound + * processes executing in kernel context might never report an + * RCU quiescent state. Therefore, the following code causes + * cond_resched() to report a quiescent state, but only when RCU + * is in urgent need of one. + */ #ifndef CONFIG_PREEMPT_RCU rcu_all_qs(); #endif @@ -7953,7 +8354,8 @@ int io_schedule_prepare(void) int old_iowait = current->in_iowait; current->in_iowait = 1; - blk_schedule_flush_plug(current); + if (current->plug) + blk_flush_plug(current->plug, true); return old_iowait; } @@ -8394,6 +8796,7 @@ void idle_task_exit(void) finish_arch_post_lock_switch(); } + scs_task_reset(current); /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ } @@ -8435,7 +8838,6 @@ static void balance_push(struct rq *rq) struct task_struct *push_task = rq->curr; lockdep_assert_rq_held(rq); - SCHED_WARN_ON(rq->cpu != smp_processor_id()); /* * Ensure the thing is persistent until balance_push_set(.on = false); @@ -8443,9 +8845,10 @@ static void balance_push(struct rq *rq) rq->balance_callback = &balance_push_callback; /* - * Only active while going offline. + * Only active while going offline and when invoked on the outgoing + * CPU. */ - if (!cpu_dying(rq->cpu)) + if (!cpu_dying(rq->cpu) || rq != this_rq()) return; /* @@ -8707,6 +9110,8 @@ int sched_cpu_deactivate(unsigned int cpu) */ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) static_branch_dec_cpuslocked(&sched_smt_present); + + sched_core_cpu_deactivate(cpu); #endif if (!sched_smp_initialized) @@ -8811,6 +9216,7 @@ int sched_cpu_dying(unsigned int cpu) calc_load_migrate(rq); update_max_interval(); hrtick_clear(rq); + sched_core_cpu_dying(cpu); return 0; } #endif @@ -9022,7 +9428,7 @@ void __init sched_init(void) atomic_set(&rq->nr_iowait, 0); #ifdef CONFIG_SCHED_CORE - rq->core = NULL; + rq->core = rq; rq->core_pick = NULL; rq->core_enabled = 0; rq->core_tree = RB_ROOT; @@ -9804,7 +10210,7 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota, * Prevent race between setting of cfs_rq->runtime_enabled and * unthrottle_offline_cfs_rqs(). */ - get_online_cpus(); + cpus_read_lock(); mutex_lock(&cfs_constraints_mutex); ret = __cfs_schedulable(tg, period, quota); if (ret) @@ -9848,7 +10254,7 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota, cfs_bandwidth_usage_dec(); out_unlock: mutex_unlock(&cfs_constraints_mutex); - put_online_cpus(); + cpus_read_unlock(); return ret; } @@ -10099,6 +10505,20 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css, } #endif /* CONFIG_RT_GROUP_SCHED */ +#ifdef CONFIG_FAIR_GROUP_SCHED +static s64 cpu_idle_read_s64(struct cgroup_subsys_state *css, + struct cftype *cft) +{ + return css_tg(css)->idle; +} + +static int cpu_idle_write_s64(struct cgroup_subsys_state *css, + struct cftype *cft, s64 idle) +{ + return sched_group_set_idle(css_tg(css), idle); +} +#endif + static struct cftype cpu_legacy_files[] = { #ifdef CONFIG_FAIR_GROUP_SCHED { @@ -10106,6 +10526,11 @@ static struct cftype cpu_legacy_files[] = { .read_u64 = cpu_shares_read_u64, .write_u64 = cpu_shares_write_u64, }, + { + .name = "idle", + .read_s64 = cpu_idle_read_s64, + .write_s64 = cpu_idle_write_s64, + }, #endif #ifdef CONFIG_CFS_BANDWIDTH { @@ -10313,6 +10738,12 @@ static struct cftype cpu_files[] = { .read_s64 = cpu_weight_nice_read_s64, .write_s64 = cpu_weight_nice_write_s64, }, + { + .name = "idle", + .flags = CFTYPE_NOT_ON_ROOT, + .read_s64 = cpu_idle_read_s64, + .write_s64 = cpu_idle_write_s64, + }, #endif #ifdef CONFIG_CFS_BANDWIDTH { diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 57124614363d..e7af18857371 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -537,9 +537,17 @@ static struct attribute *sugov_attrs[] = { }; ATTRIBUTE_GROUPS(sugov); +static void sugov_tunables_free(struct kobject *kobj) +{ + struct gov_attr_set *attr_set = container_of(kobj, struct gov_attr_set, kobj); + + kfree(to_sugov_tunables(attr_set)); +} + static struct kobj_type sugov_tunables_ktype = { .default_groups = sugov_groups, .sysfs_ops = &governor_sysfs_ops, + .release = &sugov_tunables_free, }; /********************** cpufreq governor interface *********************/ @@ -639,12 +647,10 @@ static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_polic return tunables; } -static void sugov_tunables_free(struct sugov_tunables *tunables) +static void sugov_clear_global_tunables(void) { if (!have_governor_per_policy()) global_tunables = NULL; - - kfree(tunables); } static int sugov_init(struct cpufreq_policy *policy) @@ -707,7 +713,7 @@ out: fail: kobject_put(&tunables->attr_set.kobj); policy->governor_data = NULL; - sugov_tunables_free(tunables); + sugov_clear_global_tunables(); stop_kthread: sugov_kthread_stop(sg_policy); @@ -734,7 +740,7 @@ static void sugov_exit(struct cpufreq_policy *policy) count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); policy->governor_data = NULL; if (!count) - sugov_tunables_free(tunables); + sugov_clear_global_tunables(); mutex_unlock(&global_tunables_lock); diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index aaacd6cfd42f..e94314633b39 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1733,6 +1733,7 @@ static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused */ raw_spin_rq_lock(rq); if (p->dl.dl_non_contending) { + update_rq_clock(rq); sub_running_bw(&p->dl, &rq->dl); p->dl.dl_non_contending = 0; /* @@ -2741,7 +2742,7 @@ void __setparam_dl(struct task_struct *p, const struct sched_attr *attr) dl_se->dl_runtime = attr->sched_runtime; dl_se->dl_deadline = attr->sched_deadline; dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline; - dl_se->flags = attr->sched_flags; + dl_se->flags = attr->sched_flags & SCHED_DL_FLAGS; dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime); dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime); } @@ -2754,7 +2755,8 @@ void __getparam_dl(struct task_struct *p, struct sched_attr *attr) attr->sched_runtime = dl_se->dl_runtime; attr->sched_deadline = dl_se->dl_deadline; attr->sched_period = dl_se->dl_period; - attr->sched_flags = dl_se->flags; + attr->sched_flags &= ~SCHED_DL_FLAGS; + attr->sched_flags |= dl_se->flags; } /* @@ -2851,7 +2853,7 @@ bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr) if (dl_se->dl_runtime != attr->sched_runtime || dl_se->dl_deadline != attr->sched_deadline || dl_se->dl_period != attr->sched_period || - dl_se->flags != attr->sched_flags) + dl_se->flags != (attr->sched_flags & SCHED_DL_FLAGS)) return true; return false; diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 0c5ec2776ddf..17a653b67006 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -173,16 +173,22 @@ static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { char buf[16]; + unsigned int scaling; if (cnt > 15) cnt = 15; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; + buf[cnt] = '\0'; - if (kstrtouint(buf, 10, &sysctl_sched_tunable_scaling)) + if (kstrtouint(buf, 10, &scaling)) return -EINVAL; + if (scaling >= SCHED_TUNABLESCALING_END) + return -EINVAL; + + sysctl_sched_tunable_scaling = scaling; if (sched_update_scaling()) return -EINVAL; @@ -388,6 +394,13 @@ void update_sched_domain_debugfs(void) { int cpu, i; + /* + * This can unfortunately be invoked before sched_debug_init() creates + * the debug directory. Don't touch sd_sysctl_cpus until then. + */ + if (!debugfs_sched) + return; + if (!cpumask_available(sd_sysctl_cpus)) { if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL)) return; @@ -600,6 +613,9 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) SEQ_printf(m, " .%-30s: %d\n", "nr_spread_over", cfs_rq->nr_spread_over); SEQ_printf(m, " .%-30s: %d\n", "nr_running", cfs_rq->nr_running); + SEQ_printf(m, " .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running); + SEQ_printf(m, " .%-30s: %d\n", "idle_h_nr_running", + cfs_rq->idle_h_nr_running); SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight); #ifdef CONFIG_SMP SEQ_printf(m, " .%-30s: %lu\n", "load_avg", diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 44c452072a1b..f6a05d9b5443 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -431,6 +431,23 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse) } } +static int tg_is_idle(struct task_group *tg) +{ + return tg->idle > 0; +} + +static int cfs_rq_is_idle(struct cfs_rq *cfs_rq) +{ + return cfs_rq->idle > 0; +} + +static int se_is_idle(struct sched_entity *se) +{ + if (entity_is_task(se)) + return task_has_idle_policy(task_of(se)); + return cfs_rq_is_idle(group_cfs_rq(se)); +} + #else /* !CONFIG_FAIR_GROUP_SCHED */ #define for_each_sched_entity(se) \ @@ -468,6 +485,21 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse) { } +static inline int tg_is_idle(struct task_group *tg) +{ + return 0; +} + +static int cfs_rq_is_idle(struct cfs_rq *cfs_rq) +{ + return 0; +} + +static int se_is_idle(struct sched_entity *se) +{ + return 0; +} + #endif /* CONFIG_FAIR_GROUP_SCHED */ static __always_inline @@ -1486,7 +1518,7 @@ static inline bool is_core_idle(int cpu) if (cpu == sibling) continue; - if (!idle_cpu(cpu)) + if (!idle_cpu(sibling)) return false; } #endif @@ -4841,6 +4873,9 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq) dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP); + if (cfs_rq_is_idle(group_cfs_rq(se))) + idle_task_delta = cfs_rq->h_nr_running; + qcfs_rq->h_nr_running -= task_delta; qcfs_rq->idle_h_nr_running -= idle_task_delta; @@ -4860,6 +4895,9 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq) update_load_avg(qcfs_rq, se, 0); se_update_runnable(se); + if (cfs_rq_is_idle(group_cfs_rq(se))) + idle_task_delta = cfs_rq->h_nr_running; + qcfs_rq->h_nr_running -= task_delta; qcfs_rq->idle_h_nr_running -= idle_task_delta; } @@ -4898,45 +4936,55 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) /* update hierarchical throttle state */ walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq); - if (!cfs_rq->load.weight) + /* Nothing to run but something to decay (on_list)? Complete the branch */ + if (!cfs_rq->load.weight) { + if (cfs_rq->on_list) + goto unthrottle_throttle; return; + } task_delta = cfs_rq->h_nr_running; idle_task_delta = cfs_rq->idle_h_nr_running; for_each_sched_entity(se) { + struct cfs_rq *qcfs_rq = cfs_rq_of(se); + if (se->on_rq) break; - cfs_rq = cfs_rq_of(se); - enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP); + enqueue_entity(qcfs_rq, se, ENQUEUE_WAKEUP); - cfs_rq->h_nr_running += task_delta; - cfs_rq->idle_h_nr_running += idle_task_delta; + if (cfs_rq_is_idle(group_cfs_rq(se))) + idle_task_delta = cfs_rq->h_nr_running; + + qcfs_rq->h_nr_running += task_delta; + qcfs_rq->idle_h_nr_running += idle_task_delta; /* end evaluation on encountering a throttled cfs_rq */ - if (cfs_rq_throttled(cfs_rq)) + if (cfs_rq_throttled(qcfs_rq)) goto unthrottle_throttle; } for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); + struct cfs_rq *qcfs_rq = cfs_rq_of(se); - update_load_avg(cfs_rq, se, UPDATE_TG); + update_load_avg(qcfs_rq, se, UPDATE_TG); se_update_runnable(se); - cfs_rq->h_nr_running += task_delta; - cfs_rq->idle_h_nr_running += idle_task_delta; + if (cfs_rq_is_idle(group_cfs_rq(se))) + idle_task_delta = cfs_rq->h_nr_running; + qcfs_rq->h_nr_running += task_delta; + qcfs_rq->idle_h_nr_running += idle_task_delta; /* end evaluation on encountering a throttled cfs_rq */ - if (cfs_rq_throttled(cfs_rq)) + if (cfs_rq_throttled(qcfs_rq)) goto unthrottle_throttle; /* * One parent has been throttled and cfs_rq removed from the * list. Add it back to not break the leaf list. */ - if (throttled_hierarchy(cfs_rq)) - list_add_leaf_cfs_rq(cfs_rq); + if (throttled_hierarchy(qcfs_rq)) + list_add_leaf_cfs_rq(qcfs_rq); } /* At this point se is NULL and we are at root level*/ @@ -4949,9 +4997,9 @@ unthrottle_throttle: * assertion below. */ for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); + struct cfs_rq *qcfs_rq = cfs_rq_of(se); - if (list_add_leaf_cfs_rq(cfs_rq)) + if (list_add_leaf_cfs_rq(qcfs_rq)) break; } @@ -5574,6 +5622,9 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) cfs_rq->h_nr_running++; cfs_rq->idle_h_nr_running += idle_h_nr_running; + if (cfs_rq_is_idle(cfs_rq)) + idle_h_nr_running = 1; + /* end evaluation on encountering a throttled cfs_rq */ if (cfs_rq_throttled(cfs_rq)) goto enqueue_throttle; @@ -5591,6 +5642,9 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) cfs_rq->h_nr_running++; cfs_rq->idle_h_nr_running += idle_h_nr_running; + if (cfs_rq_is_idle(cfs_rq)) + idle_h_nr_running = 1; + /* end evaluation on encountering a throttled cfs_rq */ if (cfs_rq_throttled(cfs_rq)) goto enqueue_throttle; @@ -5668,6 +5722,9 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) cfs_rq->h_nr_running--; cfs_rq->idle_h_nr_running -= idle_h_nr_running; + if (cfs_rq_is_idle(cfs_rq)) + idle_h_nr_running = 1; + /* end evaluation on encountering a throttled cfs_rq */ if (cfs_rq_throttled(cfs_rq)) goto dequeue_throttle; @@ -5697,6 +5754,9 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) cfs_rq->h_nr_running--; cfs_rq->idle_h_nr_running -= idle_h_nr_running; + if (cfs_rq_is_idle(cfs_rq)) + idle_h_nr_running = 1; + /* end evaluation on encountering a throttled cfs_rq */ if (cfs_rq_throttled(cfs_rq)) goto dequeue_throttle; @@ -6249,7 +6309,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool time = cpu_clock(this); } - for_each_cpu_wrap(cpu, cpus, target) { + for_each_cpu_wrap(cpu, cpus, target + 1) { if (has_idle_core) { i = select_idle_core(p, cpu, cpus, &idle_cpu); if ((unsigned int)i < nr_cpumask_bits) @@ -6376,6 +6436,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) /* Check a recently used CPU as a potential idle candidate: */ recent_used_cpu = p->recent_used_cpu; + p->recent_used_cpu = prev; if (recent_used_cpu != prev && recent_used_cpu != target && cpus_share_cache(recent_used_cpu, target) && @@ -6902,9 +6963,6 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags) } else if (wake_flags & WF_TTWU) { /* XXX always ? */ /* Fast path */ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu); - - if (want_affine) - current->recent_used_cpu = cpu; } rcu_read_unlock(); @@ -7041,24 +7099,22 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) static void set_last_buddy(struct sched_entity *se) { - if (entity_is_task(se) && unlikely(task_has_idle_policy(task_of(se)))) - return; - for_each_sched_entity(se) { if (SCHED_WARN_ON(!se->on_rq)) return; + if (se_is_idle(se)) + return; cfs_rq_of(se)->last = se; } } static void set_next_buddy(struct sched_entity *se) { - if (entity_is_task(se) && unlikely(task_has_idle_policy(task_of(se)))) - return; - for_each_sched_entity(se) { if (SCHED_WARN_ON(!se->on_rq)) return; + if (se_is_idle(se)) + return; cfs_rq_of(se)->next = se; } } @@ -7079,6 +7135,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ struct cfs_rq *cfs_rq = task_cfs_rq(curr); int scale = cfs_rq->nr_running >= sched_nr_latency; int next_buddy_marked = 0; + int cse_is_idle, pse_is_idle; if (unlikely(se == pse)) return; @@ -7123,8 +7180,21 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ return; find_matching_se(&se, &pse); - update_curr(cfs_rq_of(se)); BUG_ON(!pse); + + cse_is_idle = se_is_idle(se); + pse_is_idle = se_is_idle(pse); + + /* + * Preempt an idle group in favor of a non-idle group (and don't preempt + * in the inverse case). + */ + if (cse_is_idle && !pse_is_idle) + goto preempt; + if (cse_is_idle != pse_is_idle) + return; + + update_curr(cfs_rq_of(se)); if (wakeup_preempt_entity(se, pse) == 1) { /* * Bias pick_next to pick the sched entity that is @@ -10217,9 +10287,11 @@ static inline int on_null_domain(struct rq *rq) static inline int find_new_ilb(void) { int ilb; + const struct cpumask *hk_mask; - for_each_cpu_and(ilb, nohz.idle_cpus_mask, - housekeeping_cpumask(HK_FLAG_MISC)) { + hk_mask = housekeeping_cpumask(HK_FLAG_MISC); + + for_each_cpu_and(ilb, nohz.idle_cpus_mask, hk_mask) { if (ilb == smp_processor_id()) continue; @@ -11416,10 +11488,12 @@ void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, static DEFINE_MUTEX(shares_mutex); -int sched_group_set_shares(struct task_group *tg, unsigned long shares) +static int __sched_group_set_shares(struct task_group *tg, unsigned long shares) { int i; + lockdep_assert_held(&shares_mutex); + /* * We can't change the weight of the root cgroup. */ @@ -11428,9 +11502,8 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); - mutex_lock(&shares_mutex); if (tg->shares == shares) - goto done; + return 0; tg->shares = shares; for_each_possible_cpu(i) { @@ -11448,10 +11521,88 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares) rq_unlock_irqrestore(rq, &rf); } -done: + return 0; +} + +int sched_group_set_shares(struct task_group *tg, unsigned long shares) +{ + int ret; + + mutex_lock(&shares_mutex); + if (tg_is_idle(tg)) + ret = -EINVAL; + else + ret = __sched_group_set_shares(tg, shares); + mutex_unlock(&shares_mutex); + + return ret; +} + +int sched_group_set_idle(struct task_group *tg, long idle) +{ + int i; + + if (tg == &root_task_group) + return -EINVAL; + + if (idle < 0 || idle > 1) + return -EINVAL; + + mutex_lock(&shares_mutex); + + if (tg->idle == idle) { + mutex_unlock(&shares_mutex); + return 0; + } + + tg->idle = idle; + + for_each_possible_cpu(i) { + struct rq *rq = cpu_rq(i); + struct sched_entity *se = tg->se[i]; + struct cfs_rq *grp_cfs_rq = tg->cfs_rq[i]; + bool was_idle = cfs_rq_is_idle(grp_cfs_rq); + long idle_task_delta; + struct rq_flags rf; + + rq_lock_irqsave(rq, &rf); + + grp_cfs_rq->idle = idle; + if (WARN_ON_ONCE(was_idle == cfs_rq_is_idle(grp_cfs_rq))) + goto next_cpu; + + idle_task_delta = grp_cfs_rq->h_nr_running - + grp_cfs_rq->idle_h_nr_running; + if (!cfs_rq_is_idle(grp_cfs_rq)) + idle_task_delta *= -1; + + for_each_sched_entity(se) { + struct cfs_rq *cfs_rq = cfs_rq_of(se); + + if (!se->on_rq) + break; + + cfs_rq->idle_h_nr_running += idle_task_delta; + + /* Already accounted at parent level and above. */ + if (cfs_rq_is_idle(cfs_rq)) + break; + } + +next_cpu: + rq_unlock_irqrestore(rq, &rf); + } + + /* Idle groups have minimum weight. */ + if (tg_is_idle(tg)) + __sched_group_set_shares(tg, scale_load(WEIGHT_IDLEPRIO)); + else + __sched_group_set_shares(tg, NICE_0_LOAD); + mutex_unlock(&shares_mutex); return 0; } + #else /* CONFIG_FAIR_GROUP_SCHED */ void free_fair_sched_group(struct task_group *tg) { } diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 912b47aa99d8..d17b0a5ce6ac 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -379,10 +379,10 @@ void play_idle_precise(u64 duration_ns, u64 latency_ns) cpuidle_use_deepest_state(latency_ns); it.done = 0; - hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); it.timer.function = idle_inject_timer_fn; hrtimer_start(&it.timer, ns_to_ktime(duration_ns), - HRTIMER_MODE_REL_PINNED); + HRTIMER_MODE_REL_PINNED_HARD); while (!READ_ONCE(it.done)) do_idle(); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 14a41a243f7b..66128dfc05fb 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -37,7 +37,6 @@ #include <linux/binfmts.h> #include <linux/bitops.h> -#include <linux/blkdev.h> #include <linux/compat.h> #include <linux/context_tracking.h> #include <linux/cpufreq.h> @@ -227,6 +226,8 @@ static inline void update_avg(u64 *avg, u64 sample) */ #define SCHED_FLAG_SUGOV 0x10000000 +#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) + static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se) { #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL @@ -394,6 +395,9 @@ struct task_group { struct cfs_rq **cfs_rq; unsigned long shares; + /* A positive value indicates that this is a SCHED_IDLE group. */ + int idle; + #ifdef CONFIG_SMP /* * load_avg can be heavily contended at clock tick time, so put @@ -503,6 +507,8 @@ extern void sched_move_task(struct task_struct *tsk); #ifdef CONFIG_FAIR_GROUP_SCHED extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); +extern int sched_group_set_idle(struct task_group *tg, long idle); + #ifdef CONFIG_SMP extern void set_task_rq_fair(struct sched_entity *se, struct cfs_rq *prev, struct cfs_rq *next); @@ -599,6 +605,9 @@ struct cfs_rq { struct list_head leaf_cfs_rq_list; struct task_group *tg; /* group that "owns" this runqueue */ + /* Locally cached copy of our task_group's idle value */ + int idle; + #ifdef CONFIG_CFS_BANDWIDTH int runtime_enabled; s64 runtime_remaining; @@ -1093,7 +1102,7 @@ struct rq { unsigned int core_sched_seq; struct rb_root core_tree; - /* shared state */ + /* shared state -- careful with sched_core_cpu_deactivate() */ unsigned int core_task_seq; unsigned int core_pick_seq; unsigned long core_cookie; @@ -2234,6 +2243,7 @@ extern struct task_struct *pick_next_task_idle(struct rq *rq); #define SCA_CHECK 0x01 #define SCA_MIGRATE_DISABLE 0x02 #define SCA_MIGRATE_ENABLE 0x04 +#define SCA_USER 0x08 #ifdef CONFIG_SMP @@ -2255,6 +2265,9 @@ static inline struct task_struct *get_push_task(struct rq *rq) if (p->nr_cpus_allowed == 1) return NULL; + if (p->migration_disabled) + return NULL; + rq->push_busy = true; return get_task_struct(p); } @@ -2385,6 +2398,21 @@ extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); extern const_debug unsigned int sysctl_sched_nr_migrate; extern const_debug unsigned int sysctl_sched_migration_cost; +#ifdef CONFIG_SCHED_DEBUG +extern unsigned int sysctl_sched_latency; +extern unsigned int sysctl_sched_min_granularity; +extern unsigned int sysctl_sched_wakeup_granularity; +extern int sysctl_resched_latency_warn_ms; +extern int sysctl_resched_latency_warn_once; + +extern unsigned int sysctl_sched_tunable_scaling; + +extern unsigned int sysctl_numa_balancing_scan_delay; +extern unsigned int sysctl_numa_balancing_scan_period_min; +extern unsigned int sysctl_numa_balancing_scan_period_max; +extern unsigned int sysctl_numa_balancing_scan_size; +#endif + #ifdef CONFIG_SCHED_HRTICK /* diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index b77ad49dc14f..4e8698e62f07 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1482,6 +1482,8 @@ int sched_max_numa_distance; static int *sched_domains_numa_distance; static struct cpumask ***sched_domains_numa_masks; int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE; + +static unsigned long __read_mostly *sched_numa_onlined_nodes; #endif /* @@ -1833,6 +1835,16 @@ void sched_init_numa(void) sched_domains_numa_masks[i][j] = mask; for_each_node(k) { + /* + * Distance information can be unreliable for + * offline nodes, defer building the node + * masks to its bringup. + * This relies on all unique distance values + * still being visible at init time. + */ + if (!node_online(j)) + continue; + if (sched_debug() && (node_distance(j, k) != node_distance(k, j))) sched_numa_warn("Node-distance not symmetric"); @@ -1886,6 +1898,53 @@ void sched_init_numa(void) sched_max_numa_distance = sched_domains_numa_distance[nr_levels - 1]; init_numa_topology_type(); + + sched_numa_onlined_nodes = bitmap_alloc(nr_node_ids, GFP_KERNEL); + if (!sched_numa_onlined_nodes) + return; + + bitmap_zero(sched_numa_onlined_nodes, nr_node_ids); + for_each_online_node(i) + bitmap_set(sched_numa_onlined_nodes, i, 1); +} + +static void __sched_domains_numa_masks_set(unsigned int node) +{ + int i, j; + + /* + * NUMA masks are not built for offline nodes in sched_init_numa(). + * Thus, when a CPU of a never-onlined-before node gets plugged in, + * adding that new CPU to the right NUMA masks is not sufficient: the + * masks of that CPU's node must also be updated. + */ + if (test_bit(node, sched_numa_onlined_nodes)) + return; + + bitmap_set(sched_numa_onlined_nodes, node, 1); + + for (i = 0; i < sched_domains_numa_levels; i++) { + for (j = 0; j < nr_node_ids; j++) { + if (!node_online(j) || node == j) + continue; + + if (node_distance(j, node) > sched_domains_numa_distance[i]) + continue; + + /* Add remote nodes in our masks */ + cpumask_or(sched_domains_numa_masks[i][node], + sched_domains_numa_masks[i][node], + sched_domains_numa_masks[0][j]); + } + } + + /* + * A new node has been brought up, potentially changing the topology + * classification. + * + * Note that this is racy vs any use of sched_numa_topology_type :/ + */ + init_numa_topology_type(); } void sched_domains_numa_masks_set(unsigned int cpu) @@ -1893,8 +1952,14 @@ void sched_domains_numa_masks_set(unsigned int cpu) int node = cpu_to_node(cpu); int i, j; + __sched_domains_numa_masks_set(node); + for (i = 0; i < sched_domains_numa_levels; i++) { for (j = 0; j < nr_node_ids; j++) { + if (!node_online(j)) + continue; + + /* Set ourselves in the remote node's masks */ if (node_distance(j, node) <= sched_domains_numa_distance[i]) cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); } diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 6469eca8078c..4d8f44a17727 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -922,30 +922,6 @@ void get_seccomp_filter(struct task_struct *tsk) refcount_inc(&orig->users); } -static void seccomp_init_siginfo(kernel_siginfo_t *info, int syscall, int reason) -{ - clear_siginfo(info); - info->si_signo = SIGSYS; - info->si_code = SYS_SECCOMP; - info->si_call_addr = (void __user *)KSTK_EIP(current); - info->si_errno = reason; - info->si_arch = syscall_get_arch(current); - info->si_syscall = syscall; -} - -/** - * seccomp_send_sigsys - signals the task to allow in-process syscall emulation - * @syscall: syscall number to send to userland - * @reason: filter-supplied reason code to send to userland (via si_errno) - * - * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info. - */ -static void seccomp_send_sigsys(int syscall, int reason) -{ - struct kernel_siginfo info; - seccomp_init_siginfo(&info, syscall, reason); - force_sig_info(&info); -} #endif /* CONFIG_SECCOMP_FILTER */ /* For use with seccomp_actions_logged */ @@ -1218,7 +1194,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd, /* Show the handler the original registers. */ syscall_rollback(current, current_pt_regs()); /* Let the filter pass back 16 bits of data. */ - seccomp_send_sigsys(this_syscall, data); + force_sig_seccomp(this_syscall, data, false); goto skip; case SECCOMP_RET_TRACE: @@ -1288,19 +1264,15 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd, seccomp_log(this_syscall, SIGSYS, action, true); /* Dump core only if this is the last remaining thread. */ if (action != SECCOMP_RET_KILL_THREAD || - get_nr_threads(current) == 1) { - kernel_siginfo_t info; - + (atomic_read(¤t->signal->live) == 1)) { /* Show the original registers in the dump. */ syscall_rollback(current, current_pt_regs()); - /* Trigger a manual coredump since do_exit skips it. */ - seccomp_init_siginfo(&info, this_syscall, data); - do_coredump(&info); - } - if (action == SECCOMP_RET_KILL_THREAD) + /* Trigger a coredump with SIGSYS */ + force_sig_seccomp(this_syscall, data, true); + } else { do_exit(SIGSYS); - else - do_group_exit(SIGSYS); + } + return -1; /* skip the syscall go directly to signal handling */ } unreachable(); diff --git a/kernel/signal.c b/kernel/signal.c index a3229add4455..487bf4f5dadf 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -54,6 +54,7 @@ #include <asm/unistd.h> #include <asm/siginfo.h> #include <asm/cacheflush.h> +#include <asm/syscall.h> /* for syscall_get_* */ /* * SLAB caches for signal bits. @@ -425,22 +426,10 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags, */ rcu_read_lock(); ucounts = task_ucounts(t); - sigpending = inc_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1); - switch (sigpending) { - case 1: - if (likely(get_ucounts(ucounts))) - break; - fallthrough; - case LONG_MAX: - /* - * we need to decrease the ucount in the userns tree on any - * failure to avoid counts leaking. - */ - dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1); - rcu_read_unlock(); - return NULL; - } + sigpending = inc_rlimit_get_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING); rcu_read_unlock(); + if (!sigpending) + return NULL; if (override_rlimit || likely(sigpending <= task_rlimit(t, RLIMIT_SIGPENDING))) { q = kmem_cache_alloc(sigqueue_cachep, gfp_flags); @@ -449,8 +438,7 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags, } if (unlikely(q == NULL)) { - if (dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1)) - put_ucounts(ucounts); + dec_rlimit_put_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING); } else { INIT_LIST_HEAD(&q->list); q->flags = sigqueue_flags; @@ -463,8 +451,8 @@ static void __sigqueue_free(struct sigqueue *q) { if (q->flags & SIGQUEUE_PREALLOC) return; - if (q->ucounts && dec_rlimit_ucounts(q->ucounts, UCOUNT_RLIMIT_SIGPENDING, 1)) { - put_ucounts(q->ucounts); + if (q->ucounts) { + dec_rlimit_put_ucounts(q->ucounts, UCOUNT_RLIMIT_SIGPENDING); q->ucounts = NULL; } kmem_cache_free(sigqueue_cachep, q); @@ -1213,7 +1201,7 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info) case SIL_FAULT_MCEERR: case SIL_FAULT_BNDERR: case SIL_FAULT_PKUERR: - case SIL_PERF_EVENT: + case SIL_FAULT_PERF_EVENT: case SIL_SYS: ret = false; break; @@ -1322,7 +1310,7 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p * that is why we also clear SIGNAL_UNKILLABLE. */ static int -force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t) +force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool sigdfl) { unsigned long int flags; int ret, blocked, ignored; @@ -1333,7 +1321,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t) action = &t->sighand->action[sig-1]; ignored = action->sa.sa_handler == SIG_IGN; blocked = sigismember(&t->blocked, sig); - if (blocked || ignored) { + if (blocked || ignored || sigdfl) { action->sa.sa_handler = SIG_DFL; if (blocked) { sigdelset(&t->blocked, sig); @@ -1354,7 +1342,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t) int force_sig_info(struct kernel_siginfo *info) { - return force_sig_info_to_task(info, current); + return force_sig_info_to_task(info, current, false); } /* @@ -1413,6 +1401,21 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, return sighand; } +#ifdef CONFIG_LOCKDEP +void lockdep_assert_task_sighand_held(struct task_struct *task) +{ + struct sighand_struct *sighand; + + rcu_read_lock(); + sighand = rcu_dereference(task->sighand); + if (sighand) + lockdep_assert_held(&sighand->siglock); + else + WARN_ON_ONCE(1); + rcu_read_unlock(); +} +#endif + /* * send signal info to all the members of a group */ @@ -1666,7 +1669,6 @@ void force_sigsegv(int sig) } int force_sig_fault_to_task(int sig, int code, void __user *addr - ___ARCH_SI_TRAPNO(int trapno) ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) , struct task_struct *t) { @@ -1677,28 +1679,22 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr info.si_errno = 0; info.si_code = code; info.si_addr = addr; -#ifdef __ARCH_SI_TRAPNO - info.si_trapno = trapno; -#endif #ifdef __ia64__ info.si_imm = imm; info.si_flags = flags; info.si_isr = isr; #endif - return force_sig_info_to_task(&info, t); + return force_sig_info_to_task(&info, t, false); } int force_sig_fault(int sig, int code, void __user *addr - ___ARCH_SI_TRAPNO(int trapno) ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)) { return force_sig_fault_to_task(sig, code, addr - ___ARCH_SI_TRAPNO(trapno) ___ARCH_SI_IA64(imm, flags, isr), current); } int send_sig_fault(int sig, int code, void __user *addr - ___ARCH_SI_TRAPNO(int trapno) ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) , struct task_struct *t) { @@ -1709,9 +1705,6 @@ int send_sig_fault(int sig, int code, void __user *addr info.si_errno = 0; info.si_code = code; info.si_addr = addr; -#ifdef __ARCH_SI_TRAPNO - info.si_trapno = trapno; -#endif #ifdef __ia64__ info.si_imm = imm; info.si_flags = flags; @@ -1793,6 +1786,27 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data) return force_sig_info(&info); } +/** + * force_sig_seccomp - signals the task to allow in-process syscall emulation + * @syscall: syscall number to send to userland + * @reason: filter-supplied reason code to send to userland (via si_errno) + * + * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info. + */ +int force_sig_seccomp(int syscall, int reason, bool force_coredump) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = SIGSYS; + info.si_code = SYS_SECCOMP; + info.si_call_addr = (void __user *)KSTK_EIP(current); + info.si_errno = reason; + info.si_arch = syscall_get_arch(current); + info.si_syscall = syscall; + return force_sig_info_to_task(&info, current, force_coredump); +} + /* For the crazy architectures that include trap information in * the errno field, instead of an actual errno value. */ @@ -1808,6 +1822,39 @@ int force_sig_ptrace_errno_trap(int errno, void __user *addr) return force_sig_info(&info); } +/* For the rare architectures that include trap information using + * si_trapno. + */ +int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = sig; + info.si_errno = 0; + info.si_code = code; + info.si_addr = addr; + info.si_trapno = trapno; + return force_sig_info(&info); +} + +/* For the rare architectures that include trap information using + * si_trapno. + */ +int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, + struct task_struct *t) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = sig; + info.si_errno = 0; + info.si_code = code; + info.si_addr = addr; + info.si_trapno = trapno; + return send_sig_info(info.si_signo, &info, t); +} + int kill_pgrp(struct pid *pid, int sig, int priv) { int ret; @@ -2557,7 +2604,7 @@ static void hide_si_addr_tag_bits(struct ksignal *ksig) case SIL_FAULT_MCEERR: case SIL_FAULT_BNDERR: case SIL_FAULT_PKUERR: - case SIL_PERF_EVENT: + case SIL_FAULT_PERF_EVENT: ksig->info.si_addr = arch_untagged_si_addr( ksig->info.si_addr, ksig->sig, ksig->info.si_code); break; @@ -3242,11 +3289,14 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code) layout = SIL_FAULT_PKUERR; #endif else if ((sig == SIGTRAP) && (si_code == TRAP_PERF)) - layout = SIL_PERF_EVENT; -#ifdef __ARCH_SI_TRAPNO - else if (layout == SIL_FAULT) + layout = SIL_FAULT_PERF_EVENT; + else if (IS_ENABLED(CONFIG_SPARC) && + (sig == SIGILL) && (si_code == ILL_ILLTRP)) + layout = SIL_FAULT_TRAPNO; + else if (IS_ENABLED(CONFIG_ALPHA) && + ((sig == SIGFPE) || + ((sig == SIGTRAP) && (si_code == TRAP_UNK)))) layout = SIL_FAULT_TRAPNO; -#endif } else if (si_code <= NSIGPOLL) layout = SIL_POLL; @@ -3368,7 +3418,7 @@ void copy_siginfo_to_external32(struct compat_siginfo *to, to->si_addr = ptr_to_compat(from->si_addr); to->si_pkey = from->si_pkey; break; - case SIL_PERF_EVENT: + case SIL_FAULT_PERF_EVENT: to->si_addr = ptr_to_compat(from->si_addr); to->si_perf_data = from->si_perf_data; to->si_perf_type = from->si_perf_type; @@ -3445,7 +3495,7 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to, to->si_addr = compat_ptr(from->si_addr); to->si_pkey = from->si_pkey; break; - case SIL_PERF_EVENT: + case SIL_FAULT_PERF_EVENT: to->si_addr = compat_ptr(from->si_addr); to->si_perf_data = from->si_perf_data; to->si_perf_type = from->si_perf_type; @@ -4663,7 +4713,7 @@ void __init signals_init(void) { siginfo_buildtime_checks(); - sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); + sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC | SLAB_ACCOUNT); } #ifdef CONFIG_KGDB_KDB diff --git a/kernel/smp.c b/kernel/smp.c index 52bf159ec400..f43ede0ab183 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -764,7 +764,7 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, EXPORT_SYMBOL(smp_call_function_single); /** - * smp_call_function_single_async(): Run an asynchronous function on a + * smp_call_function_single_async() - Run an asynchronous function on a * specific CPU. * @cpu: The CPU to run on. * @csd: Pre-allocated and setup data structure @@ -783,6 +783,8 @@ EXPORT_SYMBOL(smp_call_function_single); * * NOTE: Be careful, there is unfortunately no current debugging facility to * validate the correctness of this serialization. + * + * Return: %0 on success or negative errno value on error */ int smp_call_function_single_async(int cpu, struct __call_single_data *csd) { @@ -974,7 +976,7 @@ static void smp_call_function_many_cond(const struct cpumask *mask, * @mask: The set of cpus to run on (only runs on online subset). * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. - * @flags: Bitmask that controls the operation. If %SCF_WAIT is set, wait + * @wait: Bitmask that controls the operation. If %SCF_WAIT is set, wait * (atomically) until function has completed on other CPUs. If * %SCF_RUN_LOCAL is set, the function will also be run locally * if the local CPU is set in the @cpumask. @@ -1180,7 +1182,13 @@ void wake_up_all_idle_cpus(void) EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); /** - * smp_call_on_cpu - Call a function on a specific cpu + * struct smp_call_on_cpu_struct - Call a function on a specific CPU + * @work: &work_struct + * @done: &completion to signal + * @func: function to call + * @data: function's data argument + * @ret: return value from @func + * @cpu: target CPU (%-1 for any CPU) * * Used to call a function on a specific cpu and wait for it to return. * Optionally make sure the call is done on a specified physical cpu via vcpu diff --git a/kernel/smpboot.c b/kernel/smpboot.c index cf6acab78538..f6bc0bc8a2aa 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -291,7 +291,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) unsigned int cpu; int ret = 0; - get_online_cpus(); + cpus_read_lock(); mutex_lock(&smpboot_threads_lock); for_each_online_cpu(cpu) { ret = __smpboot_create_thread(plug_thread, cpu); @@ -304,7 +304,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) list_add(&plug_thread->list, &hotplug_threads); out: mutex_unlock(&smpboot_threads_lock); - put_online_cpus(); + cpus_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread); @@ -317,12 +317,12 @@ EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread); */ void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread) { - get_online_cpus(); + cpus_read_lock(); mutex_lock(&smpboot_threads_lock); list_del(&plug_thread->list); smpboot_destroy_threads(plug_thread); mutex_unlock(&smpboot_threads_lock); - put_online_cpus(); + cpus_read_unlock(); } EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread); diff --git a/kernel/softirq.c b/kernel/softirq.c index f3a012179f47..322b65d45676 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -422,7 +422,7 @@ static inline void invoke_softirq(void) if (ksoftirqd_running(local_softirq_pending())) return; - if (!force_irqthreads || !__this_cpu_read(ksoftirqd)) { + if (!force_irqthreads() || !__this_cpu_read(ksoftirqd)) { #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK /* * We can safely execute softirq on the current stack if diff --git a/kernel/sys.c b/kernel/sys.c index ef1a78f5d71c..8fdac0d90504 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -480,7 +480,8 @@ static int set_user(struct cred *new) * failure to the execve() stage. */ if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) && - new_user != INIT_USER) + new_user != INIT_USER && + !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) current->flags |= PF_NPROC_EXCEEDED; else current->flags &= ~PF_NPROC_EXCEEDED; @@ -1846,7 +1847,6 @@ SYSCALL_DEFINE1(umask, int, mask) static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) { struct fd exe; - struct file *old_exe, *exe_file; struct inode *inode; int err; @@ -1869,40 +1869,10 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) if (err) goto exit; - /* - * Forbid mm->exe_file change if old file still mapped. - */ - exe_file = get_mm_exe_file(mm); - err = -EBUSY; - if (exe_file) { - struct vm_area_struct *vma; - - mmap_read_lock(mm); - for (vma = mm->mmap; vma; vma = vma->vm_next) { - if (!vma->vm_file) - continue; - if (path_equal(&vma->vm_file->f_path, - &exe_file->f_path)) - goto exit_err; - } - - mmap_read_unlock(mm); - fput(exe_file); - } - - err = 0; - /* set the new file, lockless */ - get_file(exe.file); - old_exe = xchg(&mm->exe_file, exe.file); - if (old_exe) - fput(old_exe); + err = replace_mm_exe_file(mm, exe.file); exit: fdput(exe); return err; -exit_err: - mmap_read_unlock(mm); - fput(exe_file); - goto exit; } /* @@ -1960,13 +1930,6 @@ static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) error = -EINVAL; /* - * @brk should be after @end_data in traditional maps. - */ - if (prctl_map->start_brk <= prctl_map->end_data || - prctl_map->brk <= prctl_map->end_data) - goto out; - - /* * Neither we should allow to override limits if they set. */ if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 30971b1dd4a9..f43d89d92860 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -289,17 +289,13 @@ COND_SYSCALL(munlockall); COND_SYSCALL(mincore); COND_SYSCALL(madvise); COND_SYSCALL(process_madvise); +COND_SYSCALL(process_mrelease); COND_SYSCALL(remap_file_pages); COND_SYSCALL(mbind); -COND_SYSCALL_COMPAT(mbind); COND_SYSCALL(get_mempolicy); -COND_SYSCALL_COMPAT(get_mempolicy); COND_SYSCALL(set_mempolicy); -COND_SYSCALL_COMPAT(set_mempolicy); COND_SYSCALL(migrate_pages); -COND_SYSCALL_COMPAT(migrate_pages); COND_SYSCALL(move_pages); -COND_SYSCALL_COMPAT(move_pages); COND_SYSCALL(perf_event_open); COND_SYSCALL(accept4); @@ -416,7 +412,6 @@ COND_SYSCALL(epoll_wait); COND_SYSCALL(recv); COND_SYSCALL_COMPAT(recv); COND_SYSCALL(send); -COND_SYSCALL(bdflush); COND_SYSCALL(uselib); /* optional: time32 */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 272f4a272f8c..083be6af29d7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -536,6 +536,21 @@ static void proc_put_char(void **buf, size_t *size, char c) } } +static int do_proc_dobool_conv(bool *negp, unsigned long *lvalp, + int *valp, + int write, void *data) +{ + if (write) { + *(bool *)valp = *lvalp; + } else { + int val = *(bool *)valp; + + *lvalp = (unsigned long)val; + *negp = false; + } + return 0; +} + static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) @@ -799,6 +814,26 @@ static int do_proc_douintvec(struct ctl_table *table, int write, } /** + * proc_dobool - read/write a bool + * @table: the sysctl table + * @write: %TRUE if this is a write to the sysctl file + * @buffer: the user buffer + * @lenp: the size of the user buffer + * @ppos: file position + * + * Reads/writes up to table->maxlen/sizeof(unsigned int) integer + * values from/to the user buffer, treated as an ASCII string. + * + * Returns 0 on success. + */ +int proc_dobool(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + return do_proc_dointvec(table, write, buffer, lenp, ppos, + do_proc_dobool_conv, NULL); +} + +/** * proc_dointvec - read a vector of integers * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file @@ -1630,6 +1665,12 @@ int proc_dostring(struct ctl_table *table, int write, return -ENOSYS; } +int proc_dobool(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + return -ENOSYS; +} + int proc_dointvec(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { @@ -2871,7 +2912,7 @@ static struct ctl_table vm_table[] = { .data = &sysctl_compaction_proactiveness, .maxlen = sizeof(sysctl_compaction_proactiveness), .mode = 0644, - .proc_handler = proc_dointvec_minmax, + .proc_handler = compaction_proactiveness_sysctl_handler, .extra1 = SYSCTL_ZERO, .extra2 = &one_hundred, }, @@ -3425,6 +3466,7 @@ int __init sysctl_init(void) * No sense putting this after each symbol definition, twice, * exception granted :-) */ +EXPORT_SYMBOL(proc_dobool); EXPORT_SYMBOL(proc_dointvec); EXPORT_SYMBOL(proc_douintvec); EXPORT_SYMBOL(proc_dointvec_jiffies); diff --git a/kernel/time/clocksource-wdtest.c b/kernel/time/clocksource-wdtest.c index 01df12395c0e..df922f49d171 100644 --- a/kernel/time/clocksource-wdtest.c +++ b/kernel/time/clocksource-wdtest.c @@ -19,6 +19,8 @@ #include <linux/prandom.h> #include <linux/cpu.h> +#include "tick-internal.h" + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney <paulmck@kernel.org>"); @@ -34,9 +36,6 @@ static u64 wdtest_jiffies_read(struct clocksource *cs) return (u64)jiffies; } -/* Assume HZ > 100. */ -#define JIFFIES_SHIFT 8 - static struct clocksource clocksource_wdtest_jiffies = { .name = "wdtest-jiffies", .rating = 1, /* lowest valid rating*/ diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index b89c76e1c02c..b8a14d2fb5ba 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -306,12 +306,12 @@ void clocksource_verify_percpu(struct clocksource *cs) return; cpumask_clear(&cpus_ahead); cpumask_clear(&cpus_behind); - get_online_cpus(); + cpus_read_lock(); preempt_disable(); clocksource_verify_choose_cpus(); if (cpumask_weight(&cpus_chosen) == 0) { preempt_enable(); - put_online_cpus(); + cpus_read_unlock(); pr_warn("Not enough CPUs to check clocksource '%s'.\n", cs->name); return; } @@ -337,7 +337,7 @@ void clocksource_verify_percpu(struct clocksource *cs) cs_nsec_min = cs_nsec; } preempt_enable(); - put_online_cpus(); + cpus_read_unlock(); if (!cpumask_empty(&cpus_ahead)) pr_warn(" CPUs %*pbl ahead of CPU %d for clocksource %s.\n", cpumask_pr_args(&cpus_ahead), testcpu, cs->name); diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 4a66725b1d4a..0ea8702eb516 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -652,21 +652,10 @@ static inline int hrtimer_hres_active(void) return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases)); } -/* - * Reprogram the event source with checking both queues for the - * next event - * Called with interrupts disabled and base->lock held - */ -static void -hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) +static void __hrtimer_reprogram(struct hrtimer_cpu_base *cpu_base, + struct hrtimer *next_timer, + ktime_t expires_next) { - ktime_t expires_next; - - expires_next = hrtimer_update_next_event(cpu_base); - - if (skip_equal && expires_next == cpu_base->expires_next) - return; - cpu_base->expires_next = expires_next; /* @@ -689,7 +678,25 @@ hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) if (!__hrtimer_hres_active(cpu_base) || cpu_base->hang_detected) return; - tick_program_event(cpu_base->expires_next, 1); + tick_program_event(expires_next, 1); +} + +/* + * Reprogram the event source with checking both queues for the + * next event + * Called with interrupts disabled and base->lock held + */ +static void +hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) +{ + ktime_t expires_next; + + expires_next = hrtimer_update_next_event(cpu_base); + + if (skip_equal && expires_next == cpu_base->expires_next) + return; + + __hrtimer_reprogram(cpu_base, cpu_base->next_timer, expires_next); } /* High resolution timer related functions */ @@ -720,23 +727,7 @@ static inline int hrtimer_is_hres_enabled(void) return hrtimer_hres_enabled; } -/* - * Retrigger next event is called after clock was set - * - * Called with interrupts disabled via on_each_cpu() - */ -static void retrigger_next_event(void *arg) -{ - struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases); - - if (!__hrtimer_hres_active(base)) - return; - - raw_spin_lock(&base->lock); - hrtimer_update_base(base); - hrtimer_force_reprogram(base, 0); - raw_spin_unlock(&base->lock); -} +static void retrigger_next_event(void *arg); /* * Switch to high resolution mode @@ -758,29 +749,54 @@ static void hrtimer_switch_to_hres(void) retrigger_next_event(NULL); } -static void clock_was_set_work(struct work_struct *work) -{ - clock_was_set(); -} +#else -static DECLARE_WORK(hrtimer_work, clock_was_set_work); +static inline int hrtimer_is_hres_enabled(void) { return 0; } +static inline void hrtimer_switch_to_hres(void) { } +#endif /* CONFIG_HIGH_RES_TIMERS */ /* - * Called from timekeeping and resume code to reprogram the hrtimer - * interrupt device on all cpus. + * Retrigger next event is called after clock was set with interrupts + * disabled through an SMP function call or directly from low level + * resume code. + * + * This is only invoked when: + * - CONFIG_HIGH_RES_TIMERS is enabled. + * - CONFIG_NOHZ_COMMON is enabled + * + * For the other cases this function is empty and because the call sites + * are optimized out it vanishes as well, i.e. no need for lots of + * #ifdeffery. */ -void clock_was_set_delayed(void) +static void retrigger_next_event(void *arg) { - schedule_work(&hrtimer_work); -} - -#else + struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases); -static inline int hrtimer_is_hres_enabled(void) { return 0; } -static inline void hrtimer_switch_to_hres(void) { } -static inline void retrigger_next_event(void *arg) { } + /* + * When high resolution mode or nohz is active, then the offsets of + * CLOCK_REALTIME/TAI/BOOTTIME have to be updated. Otherwise the + * next tick will take care of that. + * + * If high resolution mode is active then the next expiring timer + * must be reevaluated and the clock event device reprogrammed if + * necessary. + * + * In the NOHZ case the update of the offset and the reevaluation + * of the next expiring timer is enough. The return from the SMP + * function call will take care of the reprogramming in case the + * CPU was in a NOHZ idle sleep. + */ + if (!__hrtimer_hres_active(base) && !tick_nohz_active) + return; -#endif /* CONFIG_HIGH_RES_TIMERS */ + raw_spin_lock(&base->lock); + hrtimer_update_base(base); + if (__hrtimer_hres_active(base)) + hrtimer_force_reprogram(base, 0); + else + hrtimer_update_next_event(base); + raw_spin_unlock(&base->lock); +} /* * When a timer is enqueued and expires earlier than the already enqueued @@ -835,75 +851,161 @@ static void hrtimer_reprogram(struct hrtimer *timer, bool reprogram) if (base->cpu_base != cpu_base) return; + if (expires >= cpu_base->expires_next) + return; + /* - * If the hrtimer interrupt is running, then it will - * reevaluate the clock bases and reprogram the clock event - * device. The callbacks are always executed in hard interrupt - * context so we don't need an extra check for a running - * callback. + * If the hrtimer interrupt is running, then it will reevaluate the + * clock bases and reprogram the clock event device. */ if (cpu_base->in_hrtirq) return; - if (expires >= cpu_base->expires_next) - return; - - /* Update the pointer to the next expiring timer */ cpu_base->next_timer = timer; - cpu_base->expires_next = expires; + + __hrtimer_reprogram(cpu_base, timer, expires); +} + +static bool update_needs_ipi(struct hrtimer_cpu_base *cpu_base, + unsigned int active) +{ + struct hrtimer_clock_base *base; + unsigned int seq; + ktime_t expires; /* - * If hres is not active, hardware does not have to be - * programmed yet. + * Update the base offsets unconditionally so the following + * checks whether the SMP function call is required works. * - * If a hang was detected in the last timer interrupt then we - * do not schedule a timer which is earlier than the expiry - * which we enforced in the hang detection. We want the system - * to make progress. + * The update is safe even when the remote CPU is in the hrtimer + * interrupt or the hrtimer soft interrupt and expiring affected + * bases. Either it will see the update before handling a base or + * it will see it when it finishes the processing and reevaluates + * the next expiring timer. */ - if (!__hrtimer_hres_active(cpu_base) || cpu_base->hang_detected) - return; + seq = cpu_base->clock_was_set_seq; + hrtimer_update_base(cpu_base); + + /* + * If the sequence did not change over the update then the + * remote CPU already handled it. + */ + if (seq == cpu_base->clock_was_set_seq) + return false; + + /* + * If the remote CPU is currently handling an hrtimer interrupt, it + * will reevaluate the first expiring timer of all clock bases + * before reprogramming. Nothing to do here. + */ + if (cpu_base->in_hrtirq) + return false; /* - * Program the timer hardware. We enforce the expiry for - * events which are already in the past. + * Walk the affected clock bases and check whether the first expiring + * timer in a clock base is moving ahead of the first expiring timer of + * @cpu_base. If so, the IPI must be invoked because per CPU clock + * event devices cannot be remotely reprogrammed. */ - tick_program_event(expires, 1); + active &= cpu_base->active_bases; + + for_each_active_base(base, cpu_base, active) { + struct timerqueue_node *next; + + next = timerqueue_getnext(&base->active); + expires = ktime_sub(next->expires, base->offset); + if (expires < cpu_base->expires_next) + return true; + + /* Extra check for softirq clock bases */ + if (base->clockid < HRTIMER_BASE_MONOTONIC_SOFT) + continue; + if (cpu_base->softirq_activated) + continue; + if (expires < cpu_base->softirq_expires_next) + return true; + } + return false; } /* - * Clock realtime was set - * - * Change the offset of the realtime clock vs. the monotonic - * clock. + * Clock was set. This might affect CLOCK_REALTIME, CLOCK_TAI and + * CLOCK_BOOTTIME (for late sleep time injection). * - * We might have to reprogram the high resolution timer interrupt. On - * SMP we call the architecture specific code to retrigger _all_ high - * resolution timer interrupts. On UP we just disable interrupts and - * call the high resolution interrupt code. + * This requires to update the offsets for these clocks + * vs. CLOCK_MONOTONIC. When high resolution timers are enabled, then this + * also requires to eventually reprogram the per CPU clock event devices + * when the change moves an affected timer ahead of the first expiring + * timer on that CPU. Obviously remote per CPU clock event devices cannot + * be reprogrammed. The other reason why an IPI has to be sent is when the + * system is in !HIGH_RES and NOHZ mode. The NOHZ mode updates the offsets + * in the tick, which obviously might be stopped, so this has to bring out + * the remote CPU which might sleep in idle to get this sorted. */ -void clock_was_set(void) +void clock_was_set(unsigned int bases) { -#ifdef CONFIG_HIGH_RES_TIMERS - /* Retrigger the CPU local events everywhere */ - on_each_cpu(retrigger_next_event, NULL, 1); -#endif + struct hrtimer_cpu_base *cpu_base = raw_cpu_ptr(&hrtimer_bases); + cpumask_var_t mask; + int cpu; + + if (!__hrtimer_hres_active(cpu_base) && !tick_nohz_active) + goto out_timerfd; + + if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) { + on_each_cpu(retrigger_next_event, NULL, 1); + goto out_timerfd; + } + + /* Avoid interrupting CPUs if possible */ + cpus_read_lock(); + for_each_online_cpu(cpu) { + unsigned long flags; + + cpu_base = &per_cpu(hrtimer_bases, cpu); + raw_spin_lock_irqsave(&cpu_base->lock, flags); + + if (update_needs_ipi(cpu_base, bases)) + cpumask_set_cpu(cpu, mask); + + raw_spin_unlock_irqrestore(&cpu_base->lock, flags); + } + + preempt_disable(); + smp_call_function_many(mask, retrigger_next_event, NULL, 1); + preempt_enable(); + cpus_read_unlock(); + free_cpumask_var(mask); + +out_timerfd: timerfd_clock_was_set(); } +static void clock_was_set_work(struct work_struct *work) +{ + clock_was_set(CLOCK_SET_WALL); +} + +static DECLARE_WORK(hrtimer_work, clock_was_set_work); + +/* + * Called from timekeeping code to reprogram the hrtimer interrupt device + * on all cpus and to notify timerfd. + */ +void clock_was_set_delayed(void) +{ + schedule_work(&hrtimer_work); +} + /* - * During resume we might have to reprogram the high resolution timer - * interrupt on all online CPUs. However, all other CPUs will be - * stopped with IRQs interrupts disabled so the clock_was_set() call - * must be deferred. + * Called during resume either directly from via timekeeping_resume() + * or in the case of s2idle from tick_unfreeze() to ensure that the + * hrtimers are up to date. */ -void hrtimers_resume(void) +void hrtimers_resume_local(void) { lockdep_assert_irqs_disabled(); /* Retrigger on the local CPU */ retrigger_next_event(NULL); - /* And schedule a retrigger for all others */ - clock_was_set_delayed(); } /* @@ -1030,12 +1132,13 @@ static void __remove_hrtimer(struct hrtimer *timer, * remove hrtimer, called with base lock held */ static inline int -remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool restart) +remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, + bool restart, bool keep_local) { u8 state = timer->state; if (state & HRTIMER_STATE_ENQUEUED) { - int reprogram; + bool reprogram; /* * Remove the timer and force reprogramming when high @@ -1048,8 +1151,16 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool rest debug_deactivate(timer); reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases); + /* + * If the timer is not restarted then reprogramming is + * required if the timer is local. If it is local and about + * to be restarted, avoid programming it twice (on removal + * and a moment later when it's requeued). + */ if (!restart) state = HRTIMER_STATE_INACTIVE; + else + reprogram &= !keep_local; __remove_hrtimer(timer, base, state, reprogram); return 1; @@ -1103,9 +1214,31 @@ static int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, struct hrtimer_clock_base *base) { struct hrtimer_clock_base *new_base; + bool force_local, first; - /* Remove an active timer from the queue: */ - remove_hrtimer(timer, base, true); + /* + * If the timer is on the local cpu base and is the first expiring + * timer then this might end up reprogramming the hardware twice + * (on removal and on enqueue). To avoid that by prevent the + * reprogram on removal, keep the timer local to the current CPU + * and enforce reprogramming after it is queued no matter whether + * it is the new first expiring timer again or not. + */ + force_local = base->cpu_base == this_cpu_ptr(&hrtimer_bases); + force_local &= base->cpu_base->next_timer == timer; + + /* + * Remove an active timer from the queue. In case it is not queued + * on the current CPU, make sure that remove_hrtimer() updates the + * remote data correctly. + * + * If it's on the current CPU and the first expiring timer, then + * skip reprogramming, keep the timer local and enforce + * reprogramming later if it was the first expiring timer. This + * avoids programming the underlying clock event twice (once at + * removal and once after enqueue). + */ + remove_hrtimer(timer, base, true, force_local); if (mode & HRTIMER_MODE_REL) tim = ktime_add_safe(tim, base->get_time()); @@ -1115,9 +1248,24 @@ static int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, hrtimer_set_expires_range_ns(timer, tim, delta_ns); /* Switch the timer base, if necessary: */ - new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); + if (!force_local) { + new_base = switch_hrtimer_base(timer, base, + mode & HRTIMER_MODE_PINNED); + } else { + new_base = base; + } - return enqueue_hrtimer(timer, new_base, mode); + first = enqueue_hrtimer(timer, new_base, mode); + if (!force_local) + return first; + + /* + * Timer was forced to stay on the current CPU to avoid + * reprogramming on removal and enqueue. Force reprogram the + * hardware by evaluating the new first expiring timer. + */ + hrtimer_force_reprogram(new_base->cpu_base, 1); + return 0; } /** @@ -1183,7 +1331,7 @@ int hrtimer_try_to_cancel(struct hrtimer *timer) base = lock_hrtimer_base(timer, &flags); if (!hrtimer_callback_running(timer)) - ret = remove_hrtimer(timer, base, false); + ret = remove_hrtimer(timer, base, false, false); unlock_hrtimer_base(timer, &flags); diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index 01935aafdb46..bc4db9e5ab70 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -10,28 +10,9 @@ #include <linux/init.h> #include "timekeeping.h" +#include "tick-internal.h" -/* Since jiffies uses a simple TICK_NSEC multiplier - * conversion, the .shift value could be zero. However - * this would make NTP adjustments impossible as they are - * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to - * shift both the nominator and denominator the same - * amount, and give ntp adjustments in units of 1/2^8 - * - * The value 8 is somewhat carefully chosen, as anything - * larger can result in overflows. TICK_NSEC grows as HZ - * shrinks, so values greater than 8 overflow 32bits when - * HZ=100. - */ -#if HZ < 34 -#define JIFFIES_SHIFT 6 -#elif HZ < 67 -#define JIFFIES_SHIFT 7 -#else -#define JIFFIES_SHIFT 8 -#endif - static u64 jiffies_read(struct clocksource *cs) { return (u64) jiffies; diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index 12eab0d2ae28..aec832801c26 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -88,13 +88,13 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns, goto fail; err = -ENOMEM; - ns = kmalloc(sizeof(*ns), GFP_KERNEL); + ns = kmalloc(sizeof(*ns), GFP_KERNEL_ACCOUNT); if (!ns) goto fail_dec; refcount_set(&ns->ns.count, 1); - ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO); + ns->vvar_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!ns->vvar_page) goto fail_free; diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 517be7fd175e..643d412ac623 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -291,6 +291,8 @@ static void thread_group_start_cputime(struct task_struct *tsk, u64 *samples) struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; struct posix_cputimers *pct = &tsk->signal->posix_cputimers; + lockdep_assert_task_sighand_held(tsk); + /* Check if cputimer isn't running. This is accessed without locking. */ if (!READ_ONCE(pct->timers_active)) { struct task_cputime sum; @@ -405,6 +407,55 @@ static int posix_cpu_timer_create(struct k_itimer *new_timer) return 0; } +static struct posix_cputimer_base *timer_base(struct k_itimer *timer, + struct task_struct *tsk) +{ + int clkidx = CPUCLOCK_WHICH(timer->it_clock); + + if (CPUCLOCK_PERTHREAD(timer->it_clock)) + return tsk->posix_cputimers.bases + clkidx; + else + return tsk->signal->posix_cputimers.bases + clkidx; +} + +/* + * Force recalculating the base earliest expiration on the next tick. + * This will also re-evaluate the need to keep around the process wide + * cputime counter and tick dependency and eventually shut these down + * if necessary. + */ +static void trigger_base_recalc_expires(struct k_itimer *timer, + struct task_struct *tsk) +{ + struct posix_cputimer_base *base = timer_base(timer, tsk); + + base->nextevt = 0; +} + +/* + * Dequeue the timer and reset the base if it was its earliest expiration. + * It makes sure the next tick recalculates the base next expiration so we + * don't keep the costly process wide cputime counter around for a random + * amount of time, along with the tick dependency. + * + * If another timer gets queued between this and the next tick, its + * expiration will update the base next event if necessary on the next + * tick. + */ +static void disarm_timer(struct k_itimer *timer, struct task_struct *p) +{ + struct cpu_timer *ctmr = &timer->it.cpu; + struct posix_cputimer_base *base; + + if (!cpu_timer_dequeue(ctmr)) + return; + + base = timer_base(timer, p); + if (cpu_timer_getexpires(ctmr) == base->nextevt) + trigger_base_recalc_expires(timer, p); +} + + /* * Clean up a CPU-clock timer that is about to be destroyed. * This is called from timer deletion with the timer already locked. @@ -439,7 +490,7 @@ static int posix_cpu_timer_del(struct k_itimer *timer) if (timer->it.cpu.firing) ret = TIMER_RETRY; else - cpu_timer_dequeue(ctmr); + disarm_timer(timer, p); unlock_task_sighand(p, &flags); } @@ -498,15 +549,9 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk) */ static void arm_timer(struct k_itimer *timer, struct task_struct *p) { - int clkidx = CPUCLOCK_WHICH(timer->it_clock); + struct posix_cputimer_base *base = timer_base(timer, p); struct cpu_timer *ctmr = &timer->it.cpu; u64 newexp = cpu_timer_getexpires(ctmr); - struct posix_cputimer_base *base; - - if (CPUCLOCK_PERTHREAD(timer->it_clock)) - base = p->posix_cputimers.bases + clkidx; - else - base = p->signal->posix_cputimers.bases + clkidx; if (!cpu_timer_enqueue(&base->tqhead, ctmr)) return; @@ -703,16 +748,29 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, timer->it_overrun_last = 0; timer->it_overrun = -1; - if (new_expires != 0 && !(val < new_expires)) { + if (val >= new_expires) { + if (new_expires != 0) { + /* + * The designated time already passed, so we notify + * immediately, even if the thread never runs to + * accumulate more time on this clock. + */ + cpu_timer_fire(timer); + } + /* - * The designated time already passed, so we notify - * immediately, even if the thread never runs to - * accumulate more time on this clock. + * Make sure we don't keep around the process wide cputime + * counter or the tick dependency if they are not necessary. */ - cpu_timer_fire(timer); - } + sighand = lock_task_sighand(p, &flags); + if (!sighand) + goto out; + + if (!cpu_timer_queued(ctmr)) + trigger_base_recalc_expires(timer, p); - ret = 0; + unlock_task_sighand(p, &flags); + } out: rcu_read_unlock(); if (old) @@ -1346,9 +1404,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid, } } - if (!*newval) - return; - *newval += now; + if (*newval) + *newval += now; } /* diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index dd5697d7347b..1cd10b102c51 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -273,8 +273,8 @@ static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp) static __init int init_posix_timers(void) { posix_timers_cache = kmem_cache_create("posix_timers_cache", - sizeof (struct k_itimer), 0, SLAB_PANIC, - NULL); + sizeof(struct k_itimer), 0, + SLAB_PANIC | SLAB_ACCOUNT, NULL); return 0; } __initcall(init_posix_timers); @@ -336,7 +336,7 @@ void posixtimer_rearm(struct kernel_siginfo *info) int posix_timer_event(struct k_itimer *timr, int si_private) { enum pid_type type; - int ret = -1; + int ret; /* * FIXME: if ->sigq is queued we can race with * dequeue_signal()->posixtimer_rearm(). diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index d663249652ef..46789356f856 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -470,6 +470,13 @@ void tick_resume_local(void) else tick_resume_oneshot(); } + + /* + * Ensure that hrtimers are up to date and the clockevents device + * is reprogrammed correctly when high resolution timers are + * enabled. + */ + hrtimers_resume_local(); } /** diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 6a742a29e545..649f2b48e8f0 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -165,3 +165,35 @@ DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases); extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem); void timer_clear_idle(void); + +#define CLOCK_SET_WALL \ + (BIT(HRTIMER_BASE_REALTIME) | BIT(HRTIMER_BASE_REALTIME_SOFT) | \ + BIT(HRTIMER_BASE_TAI) | BIT(HRTIMER_BASE_TAI_SOFT)) + +#define CLOCK_SET_BOOT \ + (BIT(HRTIMER_BASE_BOOTTIME) | BIT(HRTIMER_BASE_BOOTTIME_SOFT)) + +void clock_was_set(unsigned int bases); +void clock_was_set_delayed(void); + +void hrtimers_resume_local(void); + +/* Since jiffies uses a simple TICK_NSEC multiplier + * conversion, the .shift value could be zero. However + * this would make NTP adjustments impossible as they are + * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to + * shift both the nominator and denominator the same + * amount, and give ntp adjustments in units of 1/2^8 + * + * The value 8 is somewhat carefully chosen, as anything + * larger can result in overflows. TICK_NSEC grows as HZ + * shrinks, so values greater than 8 overflow 32bits when + * HZ=100. + */ +#if HZ < 34 +#define JIFFIES_SHIFT 6 +#elif HZ < 67 +#define JIFFIES_SHIFT 7 +#else +#define JIFFIES_SHIFT 8 +#endif diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 8a364aa9881a..b348749a9fc6 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1323,8 +1323,8 @@ out: write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - /* signal hrtimers about time change */ - clock_was_set(); + /* Signal hrtimers about time change */ + clock_was_set(CLOCK_SET_WALL); if (!ret) audit_tk_injoffset(ts_delta); @@ -1371,8 +1371,8 @@ error: /* even if we error out, we forwarded the time, so call update */ write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - /* signal hrtimers about time change */ - clock_was_set(); + /* Signal hrtimers about time change */ + clock_was_set(CLOCK_SET_WALL); return ret; } @@ -1746,8 +1746,8 @@ void timekeeping_inject_sleeptime64(const struct timespec64 *delta) write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - /* signal hrtimers about time change */ - clock_was_set(); + /* Signal hrtimers about time change */ + clock_was_set(CLOCK_SET_WALL | CLOCK_SET_BOOT); } #endif @@ -1810,8 +1810,10 @@ void timekeeping_resume(void) touch_softlockup_watchdog(); + /* Resume the clockevent device(s) and hrtimers */ tick_resume(); - hrtimers_resume(); + /* Notify timerfd as resume is equivalent to clock_was_set() */ + timerfd_resume(); } int timekeeping_suspend(void) @@ -2125,7 +2127,7 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset, * timekeeping_advance - Updates the timekeeper to the current time and * current NTP tick length */ -static void timekeeping_advance(enum timekeeping_adv_mode mode) +static bool timekeeping_advance(enum timekeeping_adv_mode mode) { struct timekeeper *real_tk = &tk_core.timekeeper; struct timekeeper *tk = &shadow_timekeeper; @@ -2196,9 +2198,8 @@ static void timekeeping_advance(enum timekeeping_adv_mode mode) write_seqcount_end(&tk_core.seq); out: raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - if (clock_set) - /* Have to call _delayed version, since in irq context*/ - clock_was_set_delayed(); + + return !!clock_set; } /** @@ -2207,7 +2208,8 @@ out: */ void update_wall_time(void) { - timekeeping_advance(TK_ADV_TICK); + if (timekeeping_advance(TK_ADV_TICK)) + clock_was_set_delayed(); } /** @@ -2387,8 +2389,9 @@ int do_adjtimex(struct __kernel_timex *txc) { struct timekeeper *tk = &tk_core.timekeeper; struct audit_ntp_data ad; - unsigned long flags; + bool clock_set = false; struct timespec64 ts; + unsigned long flags; s32 orig_tai, tai; int ret; @@ -2423,6 +2426,7 @@ int do_adjtimex(struct __kernel_timex *txc) if (tai != orig_tai) { __timekeeping_set_tai_offset(tk, tai); timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); + clock_set = true; } tk_update_leap_state(tk); @@ -2433,10 +2437,10 @@ int do_adjtimex(struct __kernel_timex *txc) /* Update the multiplier immediately if frequency was set directly */ if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK)) - timekeeping_advance(TK_ADV_FREQ); + clock_set |= timekeeping_advance(TK_ADV_FREQ); - if (tai != orig_tai) - clock_was_set(); + if (clock_set) + clock_was_set(CLOCK_REALTIME); ntp_notify_cmos_timer(); diff --git a/kernel/torture.c b/kernel/torture.c index 0a315c387bed..bb8f411c974b 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -521,11 +521,11 @@ static void torture_shuffle_tasks(void) struct shuffle_task *stp; cpumask_setall(shuffle_tmp_mask); - get_online_cpus(); + cpus_read_lock(); /* No point in shuffling if there is only one online CPU (ex: UP) */ if (num_online_cpus() == 1) { - put_online_cpus(); + cpus_read_unlock(); return; } @@ -541,7 +541,7 @@ static void torture_shuffle_tasks(void) set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); mutex_unlock(&shuffle_task_mutex); - put_online_cpus(); + cpus_read_unlock(); } /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 3ee23f4d437f..420ff4bc67fd 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -135,10 +135,9 @@ config TRACING_SUPPORT depends on STACKTRACE_SUPPORT default y -if TRACING_SUPPORT - menuconfig FTRACE bool "Tracers" + depends on TRACING_SUPPORT default y if DEBUG_KERNEL help Enable the kernel tracing infrastructure. @@ -1037,6 +1036,3 @@ config HIST_TRIGGERS_DEBUG If unsure, say N. endif # FTRACE - -endif # TRACING_SUPPORT - diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index b1c47ccf4f73..6de5d4d63165 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -77,6 +77,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_event_perf.o endif obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o +obj-$(CONFIG_PROBE_EVENTS) += trace_eprobe.o obj-$(CONFIG_TRACE_EVENT_INJECT) += trace_events_inject.o obj-$(CONFIG_SYNTH_EVENTS) += trace_events_synth.o obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index c221e4c3f625..1183c88634aa 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -816,7 +816,7 @@ blk_trace_request_get_cgid(struct request *rq) * Records an action against a request. Will log the bio offset + size. * **/ -static void blk_add_trace_rq(struct request *rq, int error, +static void blk_add_trace_rq(struct request *rq, blk_status_t error, unsigned int nr_bytes, u32 what, u64 cgid) { struct blk_trace *bt; @@ -834,7 +834,8 @@ static void blk_add_trace_rq(struct request *rq, int error, what |= BLK_TC_ACT(BLK_TC_FS); __blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq), - rq->cmd_flags, what, error, 0, NULL, cgid); + rq->cmd_flags, what, blk_status_to_errno(error), 0, + NULL, cgid); rcu_read_unlock(); } @@ -863,7 +864,7 @@ static void blk_add_trace_rq_requeue(void *ignore, struct request *rq) } static void blk_add_trace_rq_complete(void *ignore, struct request *rq, - int error, unsigned int nr_bytes) + blk_status_t error, unsigned int nr_bytes) { blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE, blk_trace_request_get_cgid(rq)); @@ -1605,6 +1606,14 @@ static int blk_trace_remove_queue(struct request_queue *q) if (bt == NULL) return -EINVAL; + if (bt->trace_state == Blktrace_running) { + bt->trace_state = Blktrace_stopped; + spin_lock_irq(&running_trace_lock); + list_del_init(&bt->running_list); + spin_unlock_irq(&running_trace_lock); + relay_flush(bt->rchan); + } + put_probe_ref(); synchronize_rcu(); blk_trace_free(bt); diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index fdd14072fc3b..8e2eb950aa82 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -124,7 +124,7 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) * out of events when it was updated in between this and the * rcu_dereference() which is accepted risk. */ - ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY(call->prog_array, ctx, bpf_prog_run); out: __this_cpu_dec(bpf_prog_active); @@ -714,13 +714,28 @@ BPF_CALL_0(bpf_get_current_task_btf) return (unsigned long) current; } -BTF_ID_LIST_SINGLE(bpf_get_current_btf_ids, struct, task_struct) - -static const struct bpf_func_proto bpf_get_current_task_btf_proto = { +const struct bpf_func_proto bpf_get_current_task_btf_proto = { .func = bpf_get_current_task_btf, .gpl_only = true, .ret_type = RET_PTR_TO_BTF_ID, - .ret_btf_id = &bpf_get_current_btf_ids[0], + .ret_btf_id = &btf_task_struct_ids[0], +}; + +BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) +{ + return (unsigned long) task_pt_regs(task); +} + +BTF_ID_LIST(bpf_task_pt_regs_ids) +BTF_ID(struct, pt_regs) + +const struct bpf_func_proto bpf_task_pt_regs_proto = { + .func = bpf_task_pt_regs, + .gpl_only = true, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &btf_task_struct_ids[0], + .ret_type = RET_PTR_TO_BTF_ID, + .ret_btf_id = &bpf_task_pt_regs_ids[0], }; BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) @@ -948,7 +963,61 @@ const struct bpf_func_proto bpf_snprintf_btf_proto = { .arg5_type = ARG_ANYTHING, }; -const struct bpf_func_proto * +BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) +{ + /* This helper call is inlined by verifier. */ + return ((u64 *)ctx)[-1]; +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { + .func = bpf_get_func_ip_tracing, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) +{ + struct kprobe *kp = kprobe_running(); + + return kp ? (uintptr_t)kp->addr : 0; +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { + .func = bpf_get_func_ip_kprobe, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) +{ + struct bpf_trace_run_ctx *run_ctx; + + run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); + return run_ctx->bpf_cookie; +} + +static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { + .func = bpf_get_attach_cookie_trace, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) +{ + return ctx->event->bpf_cookie; +} + +static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { + .func = bpf_get_attach_cookie_pe, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +static const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { @@ -978,6 +1047,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_current_task_proto; case BPF_FUNC_get_current_task_btf: return &bpf_get_current_task_btf_proto; + case BPF_FUNC_task_pt_regs: + return &bpf_task_pt_regs_proto; case BPF_FUNC_get_current_uid_gid: return &bpf_get_current_uid_gid_proto; case BPF_FUNC_get_current_comm: @@ -1059,8 +1130,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_for_each_map_elem_proto; case BPF_FUNC_snprintf: return &bpf_snprintf_proto; + case BPF_FUNC_get_func_ip: + return &bpf_get_func_ip_proto_tracing; default: - return NULL; + return bpf_base_func_proto(func_id); } } @@ -1078,6 +1151,10 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_override_return: return &bpf_override_return_proto; #endif + case BPF_FUNC_get_func_ip: + return &bpf_get_func_ip_proto_kprobe; + case BPF_FUNC_get_attach_cookie: + return &bpf_get_attach_cookie_proto_trace; default: return bpf_tracing_func_proto(func_id, prog); } @@ -1188,6 +1265,8 @@ tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_stackid_proto_tp; case BPF_FUNC_get_stack: return &bpf_get_stack_proto_tp; + case BPF_FUNC_get_attach_cookie: + return &bpf_get_attach_cookie_proto_trace; default: return bpf_tracing_func_proto(func_id, prog); } @@ -1295,6 +1374,8 @@ pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_perf_prog_read_value_proto; case BPF_FUNC_read_branch_records: return &bpf_read_branch_records_proto; + case BPF_FUNC_get_attach_cookie: + return &bpf_get_attach_cookie_proto_pe; default: return bpf_tracing_func_proto(func_id, prog); } @@ -1431,6 +1512,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) const struct bpf_func_proto * tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { + const struct bpf_func_proto *fn; + switch (func_id) { #ifdef CONFIG_NET case BPF_FUNC_skb_output: @@ -1471,7 +1554,10 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_d_path: return &bpf_d_path_proto; default: - return raw_tp_prog_func_proto(func_id, prog); + fn = raw_tp_prog_func_proto(func_id, prog); + if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) + fn = bpf_iter_get_func_proto(func_id, prog); + return fn; } } @@ -1639,7 +1725,8 @@ static DEFINE_MUTEX(bpf_event_mutex); #define BPF_TRACE_MAX_PROGS 64 int perf_event_attach_bpf_prog(struct perf_event *event, - struct bpf_prog *prog) + struct bpf_prog *prog, + u64 bpf_cookie) { struct bpf_prog_array *old_array; struct bpf_prog_array *new_array; @@ -1666,12 +1753,13 @@ int perf_event_attach_bpf_prog(struct perf_event *event, goto unlock; } - ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); + ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); if (ret < 0) goto unlock; /* set the new array to event->tp_event and set event->prog */ event->prog = prog; + event->bpf_cookie = bpf_cookie; rcu_assign_pointer(event->tp_event->prog_array, new_array); bpf_prog_array_free(old_array); @@ -1692,7 +1780,7 @@ void perf_event_detach_bpf_prog(struct perf_event *event) goto unlock; old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); - ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); + ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); if (ret == -ENOENT) goto unlock; if (ret < 0) { @@ -1780,7 +1868,7 @@ void __bpf_trace_run(struct bpf_prog *prog, u64 *args) { cant_sleep(); rcu_read_lock(); - (void) BPF_PROG_RUN(prog, args); + (void) bpf_prog_run(prog, args); rcu_read_unlock(); } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7b180f61e6d3..feebf57c6458 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2208,7 +2208,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) } /** - * ftrace_update_record, set a record that now is tracing or not + * ftrace_update_record - set a record that now is tracing or not * @rec: the record to update * @enable: set to true if the record is tracing, false to force disable * @@ -2221,7 +2221,7 @@ int ftrace_update_record(struct dyn_ftrace *rec, bool enable) } /** - * ftrace_test_record, check if the record has been enabled or not + * ftrace_test_record - check if the record has been enabled or not * @rec: the record to test * @enable: set to true to check if enabled, false if it is disabled * @@ -2574,7 +2574,7 @@ struct ftrace_rec_iter { }; /** - * ftrace_rec_iter_start, start up iterating over traced functions + * ftrace_rec_iter_start - start up iterating over traced functions * * Returns an iterator handle that is used to iterate over all * the records that represent address locations where functions @@ -2605,7 +2605,7 @@ struct ftrace_rec_iter *ftrace_rec_iter_start(void) } /** - * ftrace_rec_iter_next, get the next record to process. + * ftrace_rec_iter_next - get the next record to process. * @iter: The handle to the iterator. * * Returns the next iterator after the given iterator @iter. @@ -2630,7 +2630,7 @@ struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) } /** - * ftrace_rec_iter_record, get the record at the iterator location + * ftrace_rec_iter_record - get the record at the iterator location * @iter: The current iterator location * * Returns the record that the current @iter is at. @@ -2733,7 +2733,7 @@ static int __ftrace_modify_code(void *data) } /** - * ftrace_run_stop_machine, go back to the stop machine method + * ftrace_run_stop_machine - go back to the stop machine method * @command: The command to tell ftrace what to do * * If an arch needs to fall back to the stop machine method, the @@ -2745,7 +2745,7 @@ void ftrace_run_stop_machine(int command) } /** - * arch_ftrace_update_code, modify the code to trace or not trace + * arch_ftrace_update_code - modify the code to trace or not trace * @command: The command that needs to be done * * Archs can override this function if it does not need to @@ -3100,6 +3100,7 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) { + bool init_nop = ftrace_need_init_nop(); struct ftrace_page *pg; struct dyn_ftrace *p; u64 start, stop; @@ -3138,8 +3139,7 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) * Do the initial record conversion from mcount jump * to the NOP instructions. */ - if (!__is_defined(CC_USING_NOP_MCOUNT) && - !ftrace_nop_initialize(mod, p)) + if (init_nop && !ftrace_nop_initialize(mod, p)) break; update_cnt++; @@ -6977,7 +6977,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op; int bit; - bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX); + bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); if (bit < 0) return; @@ -7052,7 +7052,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, { int bit; - bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX); + bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); if (bit < 0) return; @@ -7525,7 +7525,9 @@ void ftrace_kill(void) } /** - * Test if ftrace is dead or not. + * ftrace_is_dead - Test if ftrace is dead or not. + * + * Returns 1 if ftrace is "dead", zero otherwise. */ int ftrace_is_dead(void) { diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index e592d1df6f88..c5a3fbf19617 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2111,7 +2111,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, } } - get_online_cpus(); + cpus_read_lock(); /* * Fire off all the required work handlers * We can't schedule on offline CPUs, but it's not necessary @@ -2143,7 +2143,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, cpu_buffer->nr_pages_to_update = 0; } - put_online_cpus(); + cpus_read_unlock(); } else { cpu_buffer = buffer->buffers[cpu_id]; @@ -2171,7 +2171,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, goto out_err; } - get_online_cpus(); + cpus_read_lock(); /* Can't run something on an offline CPU. */ if (!cpu_online(cpu_id)) @@ -2183,7 +2183,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, } cpu_buffer->nr_pages_to_update = 0; - put_online_cpus(); + cpus_read_unlock(); } out: diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a1adb29ef5c1..bc677cd64224 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1744,16 +1744,15 @@ void latency_fsnotify(struct trace_array *tr) irq_work_queue(&tr->fsnotify_irqwork); } -/* - * (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \ - * defined(CONFIG_FSNOTIFY) - */ -#else +#elif defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \ + || defined(CONFIG_OSNOISE_TRACER) #define trace_create_maxlat_file(tr, d_tracer) \ trace_create_file("tracing_max_latency", 0644, d_tracer, \ &tr->max_latency, &tracing_max_lat_fops) +#else +#define trace_create_maxlat_file(tr, d_tracer) do { } while (0) #endif #ifdef CONFIG_TRACER_MAX_TRACE @@ -2603,6 +2602,15 @@ enum print_line_t trace_handle_return(struct trace_seq *s) } EXPORT_SYMBOL_GPL(trace_handle_return); +static unsigned short migration_disable_value(void) +{ +#if defined(CONFIG_SMP) + return current->migration_disabled; +#else + return 0; +#endif +} + unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status) { unsigned int trace_flags = irqs_status; @@ -2621,7 +2629,8 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status) trace_flags |= TRACE_FLAG_NEED_RESCHED; if (test_preempt_need_resched()) trace_flags |= TRACE_FLAG_PREEMPT_RESCHED; - return (trace_flags << 16) | (pc & 0xff); + return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) | + (min_t(unsigned int, migration_disable_value(), 0xf)) << 4; } struct ring_buffer_event * @@ -3697,11 +3706,11 @@ static bool trace_safe_str(struct trace_iterator *iter, const char *str) return false; event = container_of(trace_event, struct trace_event_call, event); - if (!event->mod) + if ((event->flags & TRACE_EVENT_FL_DYNAMIC) || !event->module) return false; /* Would rather have rodata, but this will suffice */ - if (within_module_core(addr, event->mod)) + if (within_module_core(addr, event->module)) return true; return false; @@ -4189,9 +4198,10 @@ static void print_lat_help_header(struct seq_file *m) "# | / _----=> need-resched \n" "# || / _---=> hardirq/softirq \n" "# ||| / _--=> preempt-depth \n" - "# |||| / delay \n" - "# cmd pid ||||| time | caller \n" - "# \\ / ||||| \\ | / \n"); + "# |||| / _-=> migrate-disable \n" + "# ||||| / delay \n" + "# cmd pid |||||| time | caller \n" + "# \\ / |||||| \\ | / \n"); } static void print_event_info(struct array_buffer *buf, struct seq_file *m) @@ -4229,9 +4239,10 @@ static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file seq_printf(m, "# %.*s / _----=> need-resched\n", prec, space); seq_printf(m, "# %.*s| / _---=> hardirq/softirq\n", prec, space); seq_printf(m, "# %.*s|| / _--=> preempt-depth\n", prec, space); - seq_printf(m, "# %.*s||| / delay\n", prec, space); - seq_printf(m, "# TASK-PID %.*s CPU# |||| TIMESTAMP FUNCTION\n", prec, " TGID "); - seq_printf(m, "# | | %.*s | |||| | |\n", prec, " | "); + seq_printf(m, "# %.*s||| / _-=> migrate-disable\n", prec, space); + seq_printf(m, "# %.*s|||| / delay\n", prec, space); + seq_printf(m, "# TASK-PID %.*s CPU# ||||| TIMESTAMP FUNCTION\n", prec, " TGID "); + seq_printf(m, "# | | %.*s | ||||| | |\n", prec, " | "); } void @@ -5543,6 +5554,7 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS "\t s:[synthetic/]<event> <field> [<field>]\n" #endif + "\t e[:[<group>/]<event>] <attached-group>.<attached-event> [<args>]\n" "\t -:[<group>/]<event>\n" #ifdef CONFIG_KPROBE_EVENTS "\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n" @@ -5552,7 +5564,7 @@ static const char readme_msg[] = " place (uprobe): <path>:<offset>[%return][(ref_ctr_offset)]\n" #endif "\t args: <name>=fetcharg[:type]\n" - "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" + "\t fetcharg: (%<register>|$<efield>), @<address>, @<symbol>[+|-<offset>],\n" #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n" #else @@ -5567,6 +5579,8 @@ static const char readme_msg[] = "\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n" "\t [unsigned] char/int/long\n" #endif + "\t efield: For event probes ('e' types), the field is on of the fields\n" + "\t of the <attached-group>/<attached-event>.\n" #endif " events/\t\t- Directory containing all trace event subsystems:\n" " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" @@ -5654,6 +5668,7 @@ static const char readme_msg[] = "\t .execname display a common_pid as a program name\n" "\t .syscall display a syscall id as a syscall name\n" "\t .log2 display log2 value rather than raw number\n" + "\t .buckets=size display values in groups of size rather than raw number\n" "\t .usecs display a common_timestamp in microseconds\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" @@ -9457,9 +9472,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) create_trace_options_dir(tr); -#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) trace_create_maxlat_file(tr, d_tracer); -#endif if (ftrace_create_function_files(tr, d_tracer)) MEM_FAIL(1, "Could not allocate function filter files"); @@ -9815,7 +9828,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) tracing_off(); local_irq_save(flags); - printk_nmi_direct_enter(); /* Simulate the iterator */ trace_init_global_iter(&iter); @@ -9897,7 +9909,6 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled); } atomic_dec(&dump_running); - printk_nmi_direct_exit(); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(ftrace_dump); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 4a0e693000c6..b7c0f8e160fb 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -126,6 +126,11 @@ struct kprobe_trace_entry_head { unsigned long ip; }; +struct eprobe_trace_entry_head { + struct trace_entry ent; + unsigned int type; +}; + struct kretprobe_trace_entry_head { struct trace_entry ent; unsigned long func; @@ -1508,9 +1513,14 @@ static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; } extern int register_trigger_cmds(void); extern void clear_event_triggers(struct trace_array *tr); +enum { + EVENT_TRIGGER_FL_PROBE = BIT(0), +}; + struct event_trigger_data { unsigned long count; int ref; + int flags; struct event_trigger_ops *ops; struct event_command *cmd_ops; struct event_filter __rcu *filter; @@ -1918,6 +1928,14 @@ static inline bool is_good_name(const char *name) return true; } +/* Convert certain expected symbols into '_' when generating event names */ +static inline void sanitize_event_name(char *name) +{ + while (*name++ != '\0') + if (*name == ':' || *name == '.') + *name = '_'; +} + /* * This is a generic way to read and write a u64 value from a file in tracefs. * diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 94ef2d099e32..8d252f63cd78 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -171,6 +171,289 @@ trace_boot_add_synth_event(struct xbc_node *node, const char *event) } #endif +#ifdef CONFIG_HIST_TRIGGERS +static int __init __printf(3, 4) +append_printf(char **bufp, char *end, const char *fmt, ...) +{ + va_list args; + int ret; + + if (*bufp == end) + return -ENOSPC; + + va_start(args, fmt); + ret = vsnprintf(*bufp, end - *bufp, fmt, args); + if (ret < end - *bufp) { + *bufp += ret; + } else { + *bufp = end; + ret = -ERANGE; + } + va_end(args); + + return ret; +} + +static int __init +append_str_nospace(char **bufp, char *end, const char *str) +{ + char *p = *bufp; + int len; + + while (p < end - 1 && *str != '\0') { + if (!isspace(*str)) + *(p++) = *str; + str++; + } + *p = '\0'; + if (p == end - 1) { + *bufp = end; + return -ENOSPC; + } + len = p - *bufp; + *bufp = p; + return (int)len; +} + +static int __init +trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp, + char *end, const char *key) +{ + struct xbc_node *anode; + const char *p; + char sep; + + p = xbc_node_find_value(hnode, key, &anode); + if (p) { + if (!anode) { + pr_err("hist.%s requires value(s).\n", key); + return -EINVAL; + } + + append_printf(bufp, end, ":%s", key); + sep = '='; + xbc_array_for_each_value(anode, p) { + append_printf(bufp, end, "%c%s", sep, p); + if (sep == '=') + sep = ','; + } + } else + return -ENOENT; + + return 0; +} + +static int __init +trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp, + char *end, const char *handler, + const char *param) +{ + struct xbc_node *knode, *anode; + const char *p; + char sep; + + /* Compose 'handler' parameter */ + p = xbc_node_find_value(hnode, param, NULL); + if (!p) { + pr_err("hist.%s requires '%s' option.\n", + xbc_node_get_data(hnode), param); + return -EINVAL; + } + append_printf(bufp, end, ":%s(%s)", handler, p); + + /* Compose 'action' parameter */ + knode = xbc_node_find_subkey(hnode, "trace"); + if (!knode) + knode = xbc_node_find_subkey(hnode, "save"); + + if (knode) { + anode = xbc_node_get_child(knode); + if (!anode || !xbc_node_is_value(anode)) { + pr_err("hist.%s.%s requires value(s).\n", + xbc_node_get_data(hnode), + xbc_node_get_data(knode)); + return -EINVAL; + } + + append_printf(bufp, end, ".%s", xbc_node_get_data(knode)); + sep = '('; + xbc_array_for_each_value(anode, p) { + append_printf(bufp, end, "%c%s", sep, p); + if (sep == '(') + sep = ','; + } + append_printf(bufp, end, ")"); + } else if (xbc_node_find_subkey(hnode, "snapshot")) { + append_printf(bufp, end, ".snapshot()"); + } else { + pr_err("hist.%s requires an action.\n", + xbc_node_get_data(hnode)); + return -EINVAL; + } + + return 0; +} + +static int __init +trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp, + char *end, const char *param) +{ + struct xbc_node *node; + const char *p, *handler; + int ret; + + handler = xbc_node_get_data(hnode); + + xbc_node_for_each_subkey(hnode, node) { + p = xbc_node_get_data(node); + if (!isdigit(p[0])) + continue; + /* All digit started node should be instances. */ + ret = trace_boot_hist_add_one_handler(node, bufp, end, handler, param); + if (ret < 0) + break; + } + + if (xbc_node_find_subkey(hnode, param)) + ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param); + + return ret; +} + +/* + * Histogram boottime tracing syntax. + * + * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] { + * keys = <KEY>[,...] + * values = <VAL>[,...] + * sort = <SORT-KEY>[,...] + * size = <ENTRIES> + * name = <HISTNAME> + * var { <VAR> = <EXPR> ... } + * pause|continue|clear + * onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] } + * onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] } + * filter = <FILTER> + * } + * + * Where <ACTION> are; + * + * trace = <EVENT>, <ARG1>[, ...] + * save = <ARG1>[, ...] + * snapshot + */ +static int __init +trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) +{ + struct xbc_node *node, *knode; + char *end = buf + size; + const char *p; + int ret = 0; + + append_printf(&buf, end, "hist"); + + ret = trace_boot_hist_add_array(hnode, &buf, end, "keys"); + if (ret < 0) { + if (ret == -ENOENT) + pr_err("hist requires keys.\n"); + return -EINVAL; + } + + ret = trace_boot_hist_add_array(hnode, &buf, end, "values"); + if (ret == -EINVAL) + return ret; + ret = trace_boot_hist_add_array(hnode, &buf, end, "sort"); + if (ret == -EINVAL) + return ret; + + p = xbc_node_find_value(hnode, "size", NULL); + if (p) + append_printf(&buf, end, ":size=%s", p); + + p = xbc_node_find_value(hnode, "name", NULL); + if (p) + append_printf(&buf, end, ":name=%s", p); + + node = xbc_node_find_subkey(hnode, "var"); + if (node) { + xbc_node_for_each_key_value(node, knode, p) { + /* Expression must not include spaces. */ + append_printf(&buf, end, ":%s=", + xbc_node_get_data(knode)); + append_str_nospace(&buf, end, p); + } + } + + /* Histogram control attributes (mutual exclusive) */ + if (xbc_node_find_value(hnode, "pause", NULL)) + append_printf(&buf, end, ":pause"); + else if (xbc_node_find_value(hnode, "continue", NULL)) + append_printf(&buf, end, ":continue"); + else if (xbc_node_find_value(hnode, "clear", NULL)) + append_printf(&buf, end, ":clear"); + + /* Histogram handler and actions */ + node = xbc_node_find_subkey(hnode, "onmax"); + if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) + return -EINVAL; + node = xbc_node_find_subkey(hnode, "onchange"); + if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) + return -EINVAL; + node = xbc_node_find_subkey(hnode, "onmatch"); + if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0) + return -EINVAL; + + p = xbc_node_find_value(hnode, "filter", NULL); + if (p) + append_printf(&buf, end, " if %s", p); + + if (buf == end) { + pr_err("hist exceeds the max command length.\n"); + return -E2BIG; + } + + return 0; +} + +static void __init +trace_boot_init_histograms(struct trace_event_file *file, + struct xbc_node *hnode, char *buf, size_t size) +{ + struct xbc_node *node; + const char *p; + char *tmp; + + xbc_node_for_each_subkey(hnode, node) { + p = xbc_node_get_data(node); + if (!isdigit(p[0])) + continue; + /* All digit started node should be instances. */ + if (trace_boot_compose_hist_cmd(node, buf, size) == 0) { + tmp = kstrdup(buf, GFP_KERNEL); + if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply hist trigger: %s\n", tmp); + kfree(tmp); + } + } + + if (xbc_node_find_subkey(hnode, "keys")) { + if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) { + tmp = kstrdup(buf, GFP_KERNEL); + if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply hist trigger: %s\n", tmp); + kfree(tmp); + } + } +} +#else +static void __init +trace_boot_init_histograms(struct trace_event_file *file, + struct xbc_node *hnode, char *buf, size_t size) +{ + /* do nothing */ +} +#endif + static void __init trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, struct xbc_node *enode) @@ -205,12 +488,18 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, pr_err("Failed to apply filter: %s\n", buf); } - xbc_node_for_each_array_value(enode, "actions", anode, p) { - if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) - pr_err("action string is too long: %s\n", p); - else if (trigger_process_regex(file, buf) < 0) - pr_err("Failed to apply an action: %s\n", buf); - } + if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) { + xbc_node_for_each_array_value(enode, "actions", anode, p) { + if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) + pr_err("action string is too long: %s\n", p); + else if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply an action: %s\n", p); + } + anode = xbc_node_find_subkey(enode, "hist"); + if (anode) + trace_boot_init_histograms(file, anode, buf, ARRAY_SIZE(buf)); + } else if (xbc_node_find_value(enode, "actions", NULL)) + pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n"); if (xbc_node_find_value(enode, "enable", NULL)) { if (trace_event_enable_disable(file, 1, 0) < 0) @@ -228,18 +517,18 @@ trace_boot_init_events(struct trace_array *tr, struct xbc_node *node) bool enable, enable_all = false; const char *data; - node = xbc_node_find_child(node, "event"); + node = xbc_node_find_subkey(node, "event"); if (!node) return; /* per-event key starts with "event.GROUP.EVENT" */ - xbc_node_for_each_child(node, gnode) { + xbc_node_for_each_subkey(node, gnode) { data = xbc_node_get_data(gnode); if (!strcmp(data, "enable")) { enable_all = true; continue; } enable = false; - xbc_node_for_each_child(gnode, enode) { + xbc_node_for_each_subkey(gnode, enode) { data = xbc_node_get_data(enode); if (!strcmp(data, "enable")) { enable = true; @@ -331,11 +620,11 @@ trace_boot_init_instances(struct xbc_node *node) struct trace_array *tr; const char *p; - node = xbc_node_find_child(node, "instance"); + node = xbc_node_find_subkey(node, "instance"); if (!node) return; - xbc_node_for_each_child(node, inode) { + xbc_node_for_each_subkey(node, inode) { p = xbc_node_get_data(inode); if (!p || *p == '\0') continue; diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index e57cc0870892..1110112e55bd 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -13,11 +13,49 @@ #include <linux/tracefs.h> #include "trace.h" +#include "trace_output.h" /* for trace_event_sem */ #include "trace_dynevent.h" static DEFINE_MUTEX(dyn_event_ops_mutex); static LIST_HEAD(dyn_event_ops_list); +bool trace_event_dyn_try_get_ref(struct trace_event_call *dyn_call) +{ + struct trace_event_call *call; + bool ret = false; + + if (WARN_ON_ONCE(!(dyn_call->flags & TRACE_EVENT_FL_DYNAMIC))) + return false; + + down_read(&trace_event_sem); + list_for_each_entry(call, &ftrace_events, list) { + if (call == dyn_call) { + atomic_inc(&dyn_call->refcnt); + ret = true; + } + } + up_read(&trace_event_sem); + return ret; +} + +void trace_event_dyn_put_ref(struct trace_event_call *call) +{ + if (WARN_ON_ONCE(!(call->flags & TRACE_EVENT_FL_DYNAMIC))) + return; + + if (WARN_ON_ONCE(atomic_read(&call->refcnt) <= 0)) { + atomic_set(&call->refcnt, 0); + return; + } + + atomic_dec(&call->refcnt); +} + +bool trace_event_dyn_busy(struct trace_event_call *call) +{ + return atomic_read(&call->refcnt) != 0; +} + int dyn_event_register(struct dyn_event_operations *ops) { if (!ops || !ops->create || !ops->show || !ops->is_busy || diff --git a/kernel/trace/trace_dynevent.h b/kernel/trace/trace_dynevent.h index 7754936b57ee..936477a111d3 100644 --- a/kernel/trace/trace_dynevent.h +++ b/kernel/trace/trace_dynevent.h @@ -76,13 +76,15 @@ int dyn_event_init(struct dyn_event *ev, struct dyn_event_operations *ops) return 0; } -static inline int dyn_event_add(struct dyn_event *ev) +static inline int dyn_event_add(struct dyn_event *ev, + struct trace_event_call *call) { lockdep_assert_held(&event_mutex); if (!ev || !ev->ops) return -EINVAL; + call->flags |= TRACE_EVENT_FL_DYNAMIC; list_add_tail(&ev->list, &dyn_event_list); return 0; } diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c new file mode 100644 index 000000000000..928867f527e7 --- /dev/null +++ b/kernel/trace/trace_eprobe.c @@ -0,0 +1,959 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * event probes + * + * Part of this code was copied from kernel/trace/trace_kprobe.c written by + * Masami Hiramatsu <mhiramat@kernel.org> + * + * Copyright (C) 2021, VMware Inc, Steven Rostedt <rostedt@goodmis.org> + * Copyright (C) 2021, VMware Inc, Tzvetomir Stoyanov tz.stoyanov@gmail.com> + * + */ +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/ftrace.h> + +#include "trace_dynevent.h" +#include "trace_probe.h" +#include "trace_probe_tmpl.h" + +#define EPROBE_EVENT_SYSTEM "eprobes" + +struct trace_eprobe { + /* tracepoint system */ + const char *event_system; + + /* tracepoint event */ + const char *event_name; + + struct trace_event_call *event; + + struct dyn_event devent; + struct trace_probe tp; +}; + +struct eprobe_data { + struct trace_event_file *file; + struct trace_eprobe *ep; +}; + +static int __trace_eprobe_create(int argc, const char *argv[]); + +static void trace_event_probe_cleanup(struct trace_eprobe *ep) +{ + if (!ep) + return; + trace_probe_cleanup(&ep->tp); + kfree(ep->event_name); + kfree(ep->event_system); + if (ep->event) + trace_event_put_ref(ep->event); + kfree(ep); +} + +static struct trace_eprobe *to_trace_eprobe(struct dyn_event *ev) +{ + return container_of(ev, struct trace_eprobe, devent); +} + +static int eprobe_dyn_event_create(const char *raw_command) +{ + return trace_probe_create(raw_command, __trace_eprobe_create); +} + +static int eprobe_dyn_event_show(struct seq_file *m, struct dyn_event *ev) +{ + struct trace_eprobe *ep = to_trace_eprobe(ev); + int i; + + seq_printf(m, "e:%s/%s", trace_probe_group_name(&ep->tp), + trace_probe_name(&ep->tp)); + seq_printf(m, " %s.%s", ep->event_system, ep->event_name); + + for (i = 0; i < ep->tp.nr_args; i++) + seq_printf(m, " %s=%s", ep->tp.args[i].name, ep->tp.args[i].comm); + seq_putc(m, '\n'); + + return 0; +} + +static int unregister_trace_eprobe(struct trace_eprobe *ep) +{ + /* If other probes are on the event, just unregister eprobe */ + if (trace_probe_has_sibling(&ep->tp)) + goto unreg; + + /* Enabled event can not be unregistered */ + if (trace_probe_is_enabled(&ep->tp)) + return -EBUSY; + + /* Will fail if probe is being used by ftrace or perf */ + if (trace_probe_unregister_event_call(&ep->tp)) + return -EBUSY; + +unreg: + dyn_event_remove(&ep->devent); + trace_probe_unlink(&ep->tp); + + return 0; +} + +static int eprobe_dyn_event_release(struct dyn_event *ev) +{ + struct trace_eprobe *ep = to_trace_eprobe(ev); + int ret = unregister_trace_eprobe(ep); + + if (!ret) + trace_event_probe_cleanup(ep); + return ret; +} + +static bool eprobe_dyn_event_is_busy(struct dyn_event *ev) +{ + struct trace_eprobe *ep = to_trace_eprobe(ev); + + return trace_probe_is_enabled(&ep->tp); +} + +static bool eprobe_dyn_event_match(const char *system, const char *event, + int argc, const char **argv, struct dyn_event *ev) +{ + struct trace_eprobe *ep = to_trace_eprobe(ev); + const char *slash; + + /* + * We match the following: + * event only - match all eprobes with event name + * system and event only - match all system/event probes + * + * The below has the above satisfied with more arguments: + * + * attached system/event - If the arg has the system and event + * the probe is attached to, match + * probes with the attachment. + * + * If any more args are given, then it requires a full match. + */ + + /* + * If system exists, but this probe is not part of that system + * do not match. + */ + if (system && strcmp(trace_probe_group_name(&ep->tp), system) != 0) + return false; + + /* Must match the event name */ + if (strcmp(trace_probe_name(&ep->tp), event) != 0) + return false; + + /* No arguments match all */ + if (argc < 1) + return true; + + /* First argument is the system/event the probe is attached to */ + + slash = strchr(argv[0], '/'); + if (!slash) + slash = strchr(argv[0], '.'); + if (!slash) + return false; + + if (strncmp(ep->event_system, argv[0], slash - argv[0])) + return false; + if (strcmp(ep->event_name, slash + 1)) + return false; + + argc--; + argv++; + + /* If there are no other args, then match */ + if (argc < 1) + return true; + + return trace_probe_match_command_args(&ep->tp, argc, argv); +} + +static struct dyn_event_operations eprobe_dyn_event_ops = { + .create = eprobe_dyn_event_create, + .show = eprobe_dyn_event_show, + .is_busy = eprobe_dyn_event_is_busy, + .free = eprobe_dyn_event_release, + .match = eprobe_dyn_event_match, +}; + +static struct trace_eprobe *alloc_event_probe(const char *group, + const char *this_event, + struct trace_event_call *event, + int nargs) +{ + struct trace_eprobe *ep; + const char *event_name; + const char *sys_name; + int ret = -ENOMEM; + + if (!event) + return ERR_PTR(-ENODEV); + + sys_name = event->class->system; + event_name = trace_event_name(event); + + ep = kzalloc(struct_size(ep, tp.args, nargs), GFP_KERNEL); + if (!ep) { + trace_event_put_ref(event); + goto error; + } + ep->event = event; + ep->event_name = kstrdup(event_name, GFP_KERNEL); + if (!ep->event_name) + goto error; + ep->event_system = kstrdup(sys_name, GFP_KERNEL); + if (!ep->event_system) + goto error; + + ret = trace_probe_init(&ep->tp, this_event, group, false); + if (ret < 0) + goto error; + + dyn_event_init(&ep->devent, &eprobe_dyn_event_ops); + return ep; +error: + trace_event_probe_cleanup(ep); + return ERR_PTR(ret); +} + +static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) +{ + struct probe_arg *parg = &ep->tp.args[i]; + struct ftrace_event_field *field; + struct list_head *head; + + head = trace_get_fields(ep->event); + list_for_each_entry(field, head, link) { + if (!strcmp(parg->code->data, field->name)) { + kfree(parg->code->data); + parg->code->data = field; + return 0; + } + } + kfree(parg->code->data); + parg->code->data = NULL; + return -ENOENT; +} + +static int eprobe_event_define_fields(struct trace_event_call *event_call) +{ + int ret; + struct eprobe_trace_entry_head field; + struct trace_probe *tp; + + tp = trace_probe_primary_from_call(event_call); + if (WARN_ON_ONCE(!tp)) + return -ENOENT; + + DEFINE_FIELD(unsigned int, type, FIELD_STRING_TYPE, 0); + + return traceprobe_define_arg_fields(event_call, sizeof(field), tp); +} + +static struct trace_event_fields eprobe_fields_array[] = { + { .type = TRACE_FUNCTION_TYPE, + .define_fields = eprobe_event_define_fields }, + {} +}; + +/* Event entry printers */ +static enum print_line_t +print_eprobe_event(struct trace_iterator *iter, int flags, + struct trace_event *event) +{ + struct eprobe_trace_entry_head *field; + struct trace_event_call *pevent; + struct trace_event *probed_event; + struct trace_seq *s = &iter->seq; + struct trace_probe *tp; + + field = (struct eprobe_trace_entry_head *)iter->ent; + tp = trace_probe_primary_from_call( + container_of(event, struct trace_event_call, event)); + if (WARN_ON_ONCE(!tp)) + goto out; + + trace_seq_printf(s, "%s: (", trace_probe_name(tp)); + + probed_event = ftrace_find_event(field->type); + if (probed_event) { + pevent = container_of(probed_event, struct trace_event_call, event); + trace_seq_printf(s, "%s.%s", pevent->class->system, + trace_event_name(pevent)); + } else { + trace_seq_printf(s, "%u", field->type); + } + + trace_seq_putc(s, ')'); + + if (print_probe_args(s, tp->args, tp->nr_args, + (u8 *)&field[1], field) < 0) + goto out; + + trace_seq_putc(s, '\n'); + out: + return trace_handle_return(s); +} + +static unsigned long get_event_field(struct fetch_insn *code, void *rec) +{ + struct ftrace_event_field *field = code->data; + unsigned long val; + void *addr; + + addr = rec + field->offset; + + switch (field->size) { + case 1: + if (field->is_signed) + val = *(char *)addr; + else + val = *(unsigned char *)addr; + break; + case 2: + if (field->is_signed) + val = *(short *)addr; + else + val = *(unsigned short *)addr; + break; + case 4: + if (field->is_signed) + val = *(int *)addr; + else + val = *(unsigned int *)addr; + break; + default: + if (field->is_signed) + val = *(long *)addr; + else + val = *(unsigned long *)addr; + break; + } + return val; +} + +static int get_eprobe_size(struct trace_probe *tp, void *rec) +{ + struct probe_arg *arg; + int i, len, ret = 0; + + for (i = 0; i < tp->nr_args; i++) { + arg = tp->args + i; + if (unlikely(arg->dynamic)) { + unsigned long val; + + val = get_event_field(arg->code, rec); + len = process_fetch_insn_bottom(arg->code + 1, val, NULL, NULL); + if (len > 0) + ret += len; + } + } + + return ret; +} + +/* Kprobe specific fetch functions */ + +/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, + void *base) +{ + unsigned long val; + + val = get_event_field(code, rec); + return process_fetch_insn_bottom(code + 1, val, dest, base); +} +NOKPROBE_SYMBOL(process_fetch_insn) + +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +fetch_store_strlen_user(unsigned long addr) +{ + const void __user *uaddr = (__force const void __user *)addr; + + return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); +} + +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +fetch_store_strlen(unsigned long addr) +{ + int ret, len = 0; + u8 c; + +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if (addr < TASK_SIZE) + return fetch_store_strlen_user(addr); +#endif + + do { + ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + return (ret < 0) ? ret : len; +} + +/* + * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf + * with max length and relative data location. + */ +static nokprobe_inline int +fetch_store_string_user(unsigned long addr, void *dest, void *base) +{ + const void __user *uaddr = (__force const void __user *)addr; + int maxlen = get_loc_len(*(u32 *)dest); + void *__dest; + long ret; + + if (unlikely(!maxlen)) + return -ENOMEM; + + __dest = get_loc_data(dest, base); + + ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, __dest - base); + + return ret; +} + +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max + * length and relative data location. + */ +static nokprobe_inline int +fetch_store_string(unsigned long addr, void *dest, void *base) +{ + int maxlen = get_loc_len(*(u32 *)dest); + void *__dest; + long ret; + +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if ((unsigned long)addr < TASK_SIZE) + return fetch_store_string_user(addr, dest, base); +#endif + + if (unlikely(!maxlen)) + return -ENOMEM; + + __dest = get_loc_data(dest, base); + + /* + * Try to get string again, since the string can be changed while + * probing. + */ + ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, __dest - base); + + return ret; +} + +static nokprobe_inline int +probe_mem_read_user(void *dest, void *src, size_t size) +{ + const void __user *uaddr = (__force const void __user *)src; + + return copy_from_user_nofault(dest, uaddr, size); +} + +static nokprobe_inline int +probe_mem_read(void *dest, void *src, size_t size) +{ +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + if ((unsigned long)src < TASK_SIZE) + return probe_mem_read_user(dest, src, size); +#endif + return copy_from_kernel_nofault(dest, src, size); +} + +/* eprobe handler */ +static inline void +__eprobe_trace_func(struct eprobe_data *edata, void *rec) +{ + struct eprobe_trace_entry_head *entry; + struct trace_event_call *call = trace_probe_event_call(&edata->ep->tp); + struct trace_event_buffer fbuffer; + int dsize; + + if (WARN_ON_ONCE(call != edata->file->event_call)) + return; + + if (trace_trigger_soft_disabled(edata->file)) + return; + + fbuffer.trace_ctx = tracing_gen_ctx(); + fbuffer.trace_file = edata->file; + + dsize = get_eprobe_size(&edata->ep->tp, rec); + fbuffer.regs = NULL; + + fbuffer.event = + trace_event_buffer_lock_reserve(&fbuffer.buffer, edata->file, + call->event.type, + sizeof(*entry) + edata->ep->tp.size + dsize, + fbuffer.trace_ctx); + if (!fbuffer.event) + return; + + entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event); + if (edata->ep->event) + entry->type = edata->ep->event->event.type; + else + entry->type = 0; + store_trace_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize); + + trace_event_buffer_commit(&fbuffer); +} + +/* + * The event probe implementation uses event triggers to get access to + * the event it is attached to, but is not an actual trigger. The below + * functions are just stubs to fulfill what is needed to use the trigger + * infrastructure. + */ +static int eprobe_trigger_init(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + return 0; +} + +static void eprobe_trigger_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + +} + +static int eprobe_trigger_print(struct seq_file *m, + struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + /* Do not print eprobe event triggers */ + return 0; +} + +static void eprobe_trigger_func(struct event_trigger_data *data, + struct trace_buffer *buffer, void *rec, + struct ring_buffer_event *rbe) +{ + struct eprobe_data *edata = data->private_data; + + __eprobe_trace_func(edata, rec); +} + +static struct event_trigger_ops eprobe_trigger_ops = { + .func = eprobe_trigger_func, + .print = eprobe_trigger_print, + .init = eprobe_trigger_init, + .free = eprobe_trigger_free, +}; + +static int eprobe_trigger_cmd_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) +{ + return -1; +} + +static int eprobe_trigger_reg_func(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + return -1; +} + +static void eprobe_trigger_unreg_func(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + +} + +static struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd, + char *param) +{ + return &eprobe_trigger_ops; +} + +static struct event_command event_trigger_cmd = { + .name = "eprobe", + .trigger_type = ETT_EVENT_EPROBE, + .flags = EVENT_CMD_FL_NEEDS_REC, + .func = eprobe_trigger_cmd_func, + .reg = eprobe_trigger_reg_func, + .unreg = eprobe_trigger_unreg_func, + .unreg_all = NULL, + .get_trigger_ops = eprobe_trigger_get_ops, + .set_filter = NULL, +}; + +static struct event_trigger_data * +new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file) +{ + struct event_trigger_data *trigger; + struct eprobe_data *edata; + + edata = kzalloc(sizeof(*edata), GFP_KERNEL); + trigger = kzalloc(sizeof(*trigger), GFP_KERNEL); + if (!trigger || !edata) { + kfree(edata); + kfree(trigger); + return ERR_PTR(-ENOMEM); + } + + trigger->flags = EVENT_TRIGGER_FL_PROBE; + trigger->count = -1; + trigger->ops = &eprobe_trigger_ops; + + /* + * EVENT PROBE triggers are not registered as commands with + * register_event_command(), as they are not controlled by the user + * from the trigger file + */ + trigger->cmd_ops = &event_trigger_cmd; + + INIT_LIST_HEAD(&trigger->list); + RCU_INIT_POINTER(trigger->filter, NULL); + + edata->file = file; + edata->ep = ep; + trigger->private_data = edata; + + return trigger; +} + +static int enable_eprobe(struct trace_eprobe *ep, + struct trace_event_file *eprobe_file) +{ + struct event_trigger_data *trigger; + struct trace_event_file *file; + struct trace_array *tr = eprobe_file->tr; + + file = find_event_file(tr, ep->event_system, ep->event_name); + if (!file) + return -ENOENT; + trigger = new_eprobe_trigger(ep, eprobe_file); + if (IS_ERR(trigger)) + return PTR_ERR(trigger); + + list_add_tail_rcu(&trigger->list, &file->triggers); + + trace_event_trigger_enable_disable(file, 1); + update_cond_flag(file); + + return 0; +} + +static struct trace_event_functions eprobe_funcs = { + .trace = print_eprobe_event +}; + +static int disable_eprobe(struct trace_eprobe *ep, + struct trace_array *tr) +{ + struct event_trigger_data *trigger; + struct trace_event_file *file; + struct eprobe_data *edata; + + file = find_event_file(tr, ep->event_system, ep->event_name); + if (!file) + return -ENOENT; + + list_for_each_entry(trigger, &file->triggers, list) { + if (!(trigger->flags & EVENT_TRIGGER_FL_PROBE)) + continue; + edata = trigger->private_data; + if (edata->ep == ep) + break; + } + if (list_entry_is_head(trigger, &file->triggers, list)) + return -ENODEV; + + list_del_rcu(&trigger->list); + + trace_event_trigger_enable_disable(file, 0); + update_cond_flag(file); + + /* Make sure nothing is using the edata or trigger */ + tracepoint_synchronize_unregister(); + + kfree(edata); + kfree(trigger); + + return 0; +} + +static int enable_trace_eprobe(struct trace_event_call *call, + struct trace_event_file *file) +{ + struct trace_probe *pos, *tp; + struct trace_eprobe *ep; + bool enabled; + int ret = 0; + + tp = trace_probe_primary_from_call(call); + if (WARN_ON_ONCE(!tp)) + return -ENODEV; + enabled = trace_probe_is_enabled(tp); + + /* This also changes "enabled" state */ + if (file) { + ret = trace_probe_add_file(tp, file); + if (ret) + return ret; + } else + trace_probe_set_flag(tp, TP_FLAG_PROFILE); + + if (enabled) + return 0; + + list_for_each_entry(pos, trace_probe_probe_list(tp), list) { + ep = container_of(pos, struct trace_eprobe, tp); + ret = enable_eprobe(ep, file); + if (ret) + break; + enabled = true; + } + + if (ret) { + /* Failed to enable one of them. Roll back all */ + if (enabled) + disable_eprobe(ep, file->tr); + if (file) + trace_probe_remove_file(tp, file); + else + trace_probe_clear_flag(tp, TP_FLAG_PROFILE); + } + + return ret; +} + +static int disable_trace_eprobe(struct trace_event_call *call, + struct trace_event_file *file) +{ + struct trace_probe *pos, *tp; + struct trace_eprobe *ep; + + tp = trace_probe_primary_from_call(call); + if (WARN_ON_ONCE(!tp)) + return -ENODEV; + + if (file) { + if (!trace_probe_get_file_link(tp, file)) + return -ENOENT; + if (!trace_probe_has_single_file(tp)) + goto out; + trace_probe_clear_flag(tp, TP_FLAG_TRACE); + } else + trace_probe_clear_flag(tp, TP_FLAG_PROFILE); + + if (!trace_probe_is_enabled(tp)) { + list_for_each_entry(pos, trace_probe_probe_list(tp), list) { + ep = container_of(pos, struct trace_eprobe, tp); + disable_eprobe(ep, file->tr); + } + } + + out: + if (file) + /* + * Synchronization is done in below function. For perf event, + * file == NULL and perf_trace_event_unreg() calls + * tracepoint_synchronize_unregister() to ensure synchronize + * event. We don't need to care about it. + */ + trace_probe_remove_file(tp, file); + + return 0; +} + +static int eprobe_register(struct trace_event_call *event, + enum trace_reg type, void *data) +{ + struct trace_event_file *file = data; + + switch (type) { + case TRACE_REG_REGISTER: + return enable_trace_eprobe(event, file); + case TRACE_REG_UNREGISTER: + return disable_trace_eprobe(event, file); +#ifdef CONFIG_PERF_EVENTS + case TRACE_REG_PERF_REGISTER: + case TRACE_REG_PERF_UNREGISTER: + case TRACE_REG_PERF_OPEN: + case TRACE_REG_PERF_CLOSE: + case TRACE_REG_PERF_ADD: + case TRACE_REG_PERF_DEL: + return 0; +#endif + } + return 0; +} + +static inline void init_trace_eprobe_call(struct trace_eprobe *ep) +{ + struct trace_event_call *call = trace_probe_event_call(&ep->tp); + + call->flags = TRACE_EVENT_FL_EPROBE; + call->event.funcs = &eprobe_funcs; + call->class->fields_array = eprobe_fields_array; + call->class->reg = eprobe_register; +} + +static struct trace_event_call * +find_and_get_event(const char *system, const char *event_name) +{ + struct trace_event_call *tp_event; + const char *name; + + list_for_each_entry(tp_event, &ftrace_events, list) { + /* Skip other probes and ftrace events */ + if (tp_event->flags & + (TRACE_EVENT_FL_IGNORE_ENABLE | + TRACE_EVENT_FL_KPROBE | + TRACE_EVENT_FL_UPROBE | + TRACE_EVENT_FL_EPROBE)) + continue; + if (!tp_event->class->system || + strcmp(system, tp_event->class->system)) + continue; + name = trace_event_name(tp_event); + if (!name || strcmp(event_name, name)) + continue; + if (!trace_event_try_get_ref(tp_event)) { + return NULL; + break; + } + return tp_event; + break; + } + return NULL; +} + +static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[], int i) +{ + unsigned int flags = TPARG_FL_KERNEL | TPARG_FL_TPOINT; + int ret; + + ret = traceprobe_parse_probe_arg(&ep->tp, i, argv[i], flags); + if (ret) + return ret; + + if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG) + ret = trace_eprobe_tp_arg_update(ep, i); + + return ret; +} + +static int __trace_eprobe_create(int argc, const char *argv[]) +{ + /* + * Argument syntax: + * e[:[GRP/]ENAME] SYSTEM.EVENT [FETCHARGS] + * Fetch args: + * <name>=$<field>[:TYPE] + */ + const char *event = NULL, *group = EPROBE_EVENT_SYSTEM; + const char *sys_event = NULL, *sys_name = NULL; + struct trace_event_call *event_call; + struct trace_eprobe *ep = NULL; + char buf1[MAX_EVENT_NAME_LEN]; + char buf2[MAX_EVENT_NAME_LEN]; + int ret = 0; + int i; + + if (argc < 2 || argv[0][0] != 'e') + return -ECANCELED; + + trace_probe_log_init("event_probe", argc, argv); + + event = strchr(&argv[0][1], ':'); + if (event) { + event++; + ret = traceprobe_parse_event_name(&event, &group, buf1, + event - argv[0]); + if (ret) + goto parse_error; + } else { + strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); + sanitize_event_name(buf1); + event = buf1; + } + if (!is_good_name(event) || !is_good_name(group)) + goto parse_error; + + sys_event = argv[1]; + ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, + sys_event - argv[1]); + if (ret || !sys_name) + goto parse_error; + if (!is_good_name(sys_event) || !is_good_name(sys_name)) + goto parse_error; + + mutex_lock(&event_mutex); + event_call = find_and_get_event(sys_name, sys_event); + ep = alloc_event_probe(group, event, event_call, argc - 2); + mutex_unlock(&event_mutex); + + if (IS_ERR(ep)) { + ret = PTR_ERR(ep); + /* This must return -ENOMEM or missing event, else there is a bug */ + WARN_ON_ONCE(ret != -ENOMEM && ret != -ENODEV); + ep = NULL; + goto error; + } + + argc -= 2; argv += 2; + /* parse arguments */ + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + trace_probe_log_set_index(i + 2); + ret = trace_eprobe_tp_update_arg(ep, argv, i); + if (ret) + goto error; + } + ret = traceprobe_set_print_fmt(&ep->tp, PROBE_PRINT_EVENT); + if (ret < 0) + goto error; + init_trace_eprobe_call(ep); + mutex_lock(&event_mutex); + ret = trace_probe_register_event_call(&ep->tp); + if (ret) { + if (ret == -EEXIST) { + trace_probe_log_set_index(0); + trace_probe_log_err(0, EVENT_EXIST); + } + mutex_unlock(&event_mutex); + goto error; + } + ret = dyn_event_add(&ep->devent, &ep->tp.event->call); + mutex_unlock(&event_mutex); + return ret; +parse_error: + ret = -EINVAL; +error: + trace_event_probe_cleanup(ep); + return ret; +} + +/* + * Register dynevent at core_initcall. This allows kernel to setup eprobe + * events in postcore_initcall without tracefs. + */ +static __init int trace_events_eprobe_init_early(void) +{ + int err = 0; + + err = dyn_event_register(&eprobe_dyn_event_ops); + if (err) + pr_warn("Could not register eprobe_dyn_event_ops\n"); + + return err; +} +core_initcall(trace_events_eprobe_init_early); diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 03be4435d103..6aed10e2f7ce 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -177,7 +177,7 @@ static void perf_trace_event_unreg(struct perf_event *p_event) } } out: - module_put(tp_event->mod); + trace_event_put_ref(tp_event); } static int perf_trace_event_open(struct perf_event *p_event) @@ -224,10 +224,10 @@ int perf_trace_init(struct perf_event *p_event) list_for_each_entry(tp_event, &ftrace_events, list) { if (tp_event->event.type == event_id && tp_event->class && tp_event->class->reg && - try_module_get(tp_event->mod)) { + trace_event_try_get_ref(tp_event)) { ret = perf_trace_event_init(tp_event, p_event); if (ret) - module_put(tp_event->mod); + trace_event_put_ref(tp_event); break; } } diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 80e96989770e..830b3b9940f4 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -181,6 +181,7 @@ static int trace_define_common_fields(void) __common_field(unsigned short, type); __common_field(unsigned char, flags); + /* Holds both preempt_count and migrate_disable */ __common_field(unsigned char, preempt_count); __common_field(int, pid); @@ -2525,7 +2526,10 @@ __register_event(struct trace_event_call *call, struct module *mod) return ret; list_add(&call->list, &ftrace_events); - call->mod = mod; + if (call->flags & TRACE_EVENT_FL_DYNAMIC) + atomic_set(&call->refcnt, 0); + else + call->module = mod; return 0; } @@ -2839,7 +2843,9 @@ static void trace_module_remove_events(struct module *mod) down_write(&trace_event_sem); list_for_each_entry_safe(call, p, &ftrace_events, list) { - if (call->mod == mod) + if ((call->flags & TRACE_EVENT_FL_DYNAMIC) || !call->module) + continue; + if (call->module == mod) __trace_remove_event_call(call); } up_write(&trace_event_sem); @@ -2982,7 +2988,7 @@ struct trace_event_file *trace_get_event_file(const char *instance, } /* Don't let event modules unload while in use */ - ret = try_module_get(file->event_call->mod); + ret = trace_event_try_get_ref(file->event_call); if (!ret) { trace_array_put(tr); ret = -EBUSY; @@ -3012,7 +3018,7 @@ EXPORT_SYMBOL_GPL(trace_get_event_file); void trace_put_event_file(struct trace_event_file *file) { mutex_lock(&event_mutex); - module_put(file->event_call->mod); + trace_event_put_ref(file->event_call); mutex_unlock(&event_mutex); trace_array_put(file->tr); @@ -3147,7 +3153,7 @@ static int free_probe_data(void *data) if (!edata->ref) { /* Remove the SOFT_MODE flag */ __ftrace_event_enable_disable(edata->file, 0, 1); - module_put(edata->file->event_call->mod); + trace_event_put_ref(edata->file->event_call); kfree(edata); } return 0; @@ -3280,7 +3286,7 @@ event_enable_func(struct trace_array *tr, struct ftrace_hash *hash, out_reg: /* Don't let event modules unload while probe registered */ - ret = try_module_get(file->event_call->mod); + ret = trace_event_try_get_ref(file->event_call); if (!ret) { ret = -EBUSY; goto out_free; @@ -3310,7 +3316,7 @@ event_enable_func(struct trace_array *tr, struct ftrace_hash *hash, out_disable: __ftrace_event_enable_disable(file, 0, 1); out_put: - module_put(file->event_call->mod); + trace_event_put_ref(file->event_call); out_free: kfree(data); goto out; @@ -3376,7 +3382,8 @@ void __trace_early_add_events(struct trace_array *tr) list_for_each_entry(call, &ftrace_events, list) { /* Early boot up should not have any modules loaded */ - if (WARN_ON_ONCE(call->mod)) + if (!(call->flags & TRACE_EVENT_FL_DYNAMIC) && + WARN_ON_ONCE(call->module)) continue; ret = __trace_early_add_new_event(call, tr); diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index a48aa2a2875b..f01e442716e2 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -121,6 +121,7 @@ struct hist_field { unsigned int size; unsigned int offset; unsigned int is_signed; + unsigned long buckets; const char *type; struct hist_field *operands[HIST_FIELD_OPERANDS_MAX]; struct hist_trigger_data *hist_data; @@ -219,6 +220,27 @@ static u64 hist_field_log2(struct hist_field *hist_field, return (u64) ilog2(roundup_pow_of_two(val)); } +static u64 hist_field_bucket(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct trace_buffer *buffer, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand = hist_field->operands[0]; + unsigned long buckets = hist_field->buckets; + + u64 val = operand->fn(operand, elt, buffer, rbe, event); + + if (WARN_ON_ONCE(!buckets)) + return val; + + if (val >= LONG_MAX) + val = div64_ul(val, buckets); + else + val = (u64)((unsigned long)val / buckets); + return val * buckets; +} + static u64 hist_field_plus(struct hist_field *hist_field, struct tracing_map_elt *elt, struct trace_buffer *buffer, @@ -318,6 +340,7 @@ enum hist_field_flags { HIST_FIELD_FL_VAR_REF = 1 << 14, HIST_FIELD_FL_CPU = 1 << 15, HIST_FIELD_FL_ALIAS = 1 << 16, + HIST_FIELD_FL_BUCKET = 1 << 17, }; struct var_defs { @@ -485,7 +508,8 @@ struct track_data { struct hist_elt_data { char *comm; u64 *var_ref_vals; - char *field_var_str[SYNTH_FIELDS_MAX]; + char **field_var_str; + int n_field_var_str; }; struct snapshot_context { @@ -1109,7 +1133,8 @@ static const char *hist_field_name(struct hist_field *field, if (field->field) field_name = field->field->name; else if (field->flags & HIST_FIELD_FL_LOG2 || - field->flags & HIST_FIELD_FL_ALIAS) + field->flags & HIST_FIELD_FL_ALIAS || + field->flags & HIST_FIELD_FL_BUCKET) field_name = hist_field_name(field->operands[0], ++level); else if (field->flags & HIST_FIELD_FL_CPU) field_name = "common_cpu"; @@ -1377,9 +1402,11 @@ static void hist_elt_data_free(struct hist_elt_data *elt_data) { unsigned int i; - for (i = 0; i < SYNTH_FIELDS_MAX; i++) + for (i = 0; i < elt_data->n_field_var_str; i++) kfree(elt_data->field_var_str[i]); + kfree(elt_data->field_var_str); + kfree(elt_data->comm); kfree(elt_data); } @@ -1396,17 +1423,17 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt) struct hist_trigger_data *hist_data = elt->map->private_data; unsigned int size = TASK_COMM_LEN; struct hist_elt_data *elt_data; - struct hist_field *key_field; + struct hist_field *hist_field; unsigned int i, n_str; elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL); if (!elt_data) return -ENOMEM; - for_each_hist_key_field(i, hist_data) { - key_field = hist_data->fields[i]; + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; - if (key_field->flags & HIST_FIELD_FL_EXECNAME) { + if (hist_field->flags & HIST_FIELD_FL_EXECNAME) { elt_data->comm = kzalloc(size, GFP_KERNEL); if (!elt_data->comm) { kfree(elt_data); @@ -1427,6 +1454,13 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt) size = STR_VAR_LEN_MAX; + elt_data->field_var_str = kcalloc(n_str, sizeof(char *), GFP_KERNEL); + if (!elt_data->field_var_str) { + hist_elt_data_free(elt_data); + return -EINVAL; + } + elt_data->n_field_var_str = n_str; + for (i = 0; i < n_str; i++) { elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL); if (!elt_data->field_var_str[i]) { @@ -1470,6 +1504,8 @@ static const char *get_hist_field_flags(struct hist_field *hist_field) flags_str = "syscall"; else if (hist_field->flags & HIST_FIELD_FL_LOG2) flags_str = "log2"; + else if (hist_field->flags & HIST_FIELD_FL_BUCKET) + flags_str = "buckets"; else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS) flags_str = "usecs"; @@ -1590,7 +1626,9 @@ static void __destroy_hist_field(struct hist_field *hist_field) kfree(hist_field->var.name); kfree(hist_field->name); - kfree(hist_field->type); + + /* Can likely be a const */ + kfree_const(hist_field->type); kfree(hist_field->system); kfree(hist_field->event_name); @@ -1647,9 +1685,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, if (flags & HIST_FIELD_FL_HITCOUNT) { hist_field->fn = hist_field_counter; hist_field->size = sizeof(u64); - hist_field->type = kstrdup("u64", GFP_KERNEL); - if (!hist_field->type) - goto free; + hist_field->type = "u64"; goto out; } @@ -1658,12 +1694,13 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, goto out; } - if (flags & HIST_FIELD_FL_LOG2) { - unsigned long fl = flags & ~HIST_FIELD_FL_LOG2; - hist_field->fn = hist_field_log2; + if (flags & (HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET)) { + unsigned long fl = flags & ~(HIST_FIELD_FL_LOG2 | HIST_FIELD_FL_BUCKET); + hist_field->fn = flags & HIST_FIELD_FL_LOG2 ? hist_field_log2 : + hist_field_bucket; hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); hist_field->size = hist_field->operands[0]->size; - hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL); + hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL); if (!hist_field->type) goto free; goto out; @@ -1672,18 +1709,14 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, if (flags & HIST_FIELD_FL_TIMESTAMP) { hist_field->fn = hist_field_timestamp; hist_field->size = sizeof(u64); - hist_field->type = kstrdup("u64", GFP_KERNEL); - if (!hist_field->type) - goto free; + hist_field->type = "u64"; goto out; } if (flags & HIST_FIELD_FL_CPU) { hist_field->fn = hist_field_cpu; hist_field->size = sizeof(int); - hist_field->type = kstrdup("unsigned int", GFP_KERNEL); - if (!hist_field->type) - goto free; + hist_field->type = "unsigned int"; goto out; } @@ -1696,7 +1729,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_FL_STRING; hist_field->size = MAX_FILTER_STR_VAL; - hist_field->type = kstrdup(field->type, GFP_KERNEL); + hist_field->type = kstrdup_const(field->type, GFP_KERNEL); if (!hist_field->type) goto free; @@ -1709,7 +1742,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, } else { hist_field->size = field->size; hist_field->is_signed = field->is_signed; - hist_field->type = kstrdup(field->type, GFP_KERNEL); + hist_field->type = kstrdup_const(field->type, GFP_KERNEL); if (!hist_field->type) goto free; @@ -1795,7 +1828,7 @@ static int init_var_ref(struct hist_field *ref_field, } } - ref_field->type = kstrdup(var_field->type, GFP_KERNEL); + ref_field->type = kstrdup_const(var_field->type, GFP_KERNEL); if (!ref_field->type) { err = -ENOMEM; goto free; @@ -1953,7 +1986,7 @@ static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data, static struct ftrace_event_field * parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, - char *field_str, unsigned long *flags) + char *field_str, unsigned long *flags, unsigned long *buckets) { struct ftrace_event_field *field = NULL; char *field_name, *modifier, *str; @@ -1980,7 +2013,22 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, *flags |= HIST_FIELD_FL_LOG2; else if (strcmp(modifier, "usecs") == 0) *flags |= HIST_FIELD_FL_TIMESTAMP_USECS; - else { + else if (strncmp(modifier, "bucket", 6) == 0) { + int ret; + + modifier += 6; + + if (*modifier == 's') + modifier++; + if (*modifier != '=') + goto error; + modifier++; + ret = kstrtoul(modifier, 0, buckets); + if (ret || !(*buckets)) + goto error; + *flags |= HIST_FIELD_FL_BUCKET; + } else { + error: hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier)); field = ERR_PTR(-EINVAL); goto out; @@ -2049,6 +2097,7 @@ static struct hist_field *parse_atom(struct hist_trigger_data *hist_data, char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str; struct ftrace_event_field *field = NULL; struct hist_field *hist_field = NULL; + unsigned long buckets = 0; int ret = 0; s = strchr(str, '.'); @@ -2086,7 +2135,7 @@ static struct hist_field *parse_atom(struct hist_trigger_data *hist_data, } else str = s; - field = parse_field(hist_data, file, str, flags); + field = parse_field(hist_data, file, str, flags, &buckets); if (IS_ERR(field)) { ret = PTR_ERR(field); goto out; @@ -2097,6 +2146,7 @@ static struct hist_field *parse_atom(struct hist_trigger_data *hist_data, ret = -ENOMEM; goto out; } + hist_field->buckets = buckets; return hist_field; out: @@ -2171,7 +2221,7 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, expr->operands[0] = operand1; expr->operator = FIELD_OP_UNARY_MINUS; expr->name = expr_str(expr, 0); - expr->type = kstrdup(operand1->type, GFP_KERNEL); + expr->type = kstrdup_const(operand1->type, GFP_KERNEL); if (!expr->type) { ret = -ENOMEM; goto free; @@ -2311,7 +2361,7 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, expr->operator = field_op; expr->name = expr_str(expr, 0); - expr->type = kstrdup(operand1->type, GFP_KERNEL); + expr->type = kstrdup_const(operand1->type, GFP_KERNEL); if (!expr->type) { ret = -ENOMEM; goto free; @@ -2456,7 +2506,7 @@ find_synthetic_field_var(struct hist_trigger_data *target_hist_data, * events. However, for convenience, users are allowed to directly * specify an event field in an action, which will be automatically * converted into a variable on their behalf. - + * * If a user specifies a field on an event that isn't the event the * histogram currently being defined (the target event histogram), the * only way that can be accomplished is if a new hist trigger is @@ -2699,10 +2749,10 @@ static struct hist_field *create_var(struct hist_trigger_data *hist_data, var->var.hist_data = var->hist_data = hist_data; var->size = size; var->var.name = kstrdup(name, GFP_KERNEL); - var->type = kstrdup(type, GFP_KERNEL); + var->type = kstrdup_const(type, GFP_KERNEL); if (!var->var.name || !var->type) { + kfree_const(var->type); kfree(var->var.name); - kfree(var->type); kfree(var); var = ERR_PTR(-ENOMEM); } @@ -3731,6 +3781,41 @@ static int create_val_field(struct hist_trigger_data *hist_data, return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0); } +static const char *no_comm = "(no comm)"; + +static u64 hist_field_execname(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct trace_buffer *buffer, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_elt_data *elt_data; + + if (WARN_ON_ONCE(!elt)) + return (u64)(unsigned long)no_comm; + + elt_data = elt->private_data; + + if (WARN_ON_ONCE(!elt_data->comm)) + return (u64)(unsigned long)no_comm; + + return (u64)(unsigned long)(elt_data->comm); +} + +/* Convert a var that points to common_pid.execname to a string */ +static void update_var_execname(struct hist_field *hist_field) +{ + hist_field->flags = HIST_FIELD_FL_STRING | HIST_FIELD_FL_VAR | + HIST_FIELD_FL_EXECNAME; + hist_field->size = MAX_FILTER_STR_VAL; + hist_field->is_signed = 0; + + kfree_const(hist_field->type); + hist_field->type = "char[]"; + + hist_field->fn = hist_field_execname; +} + static int create_var_field(struct hist_trigger_data *hist_data, unsigned int val_idx, struct trace_event_file *file, @@ -3755,6 +3840,9 @@ static int create_var_field(struct hist_trigger_data *hist_data, ret = __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags); + if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_EXECNAME) + update_var_execname(hist_data->fields[val_idx]); + if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_STRING) hist_data->fields[val_idx]->var_str_idx = hist_data->n_var_str++; @@ -4698,6 +4786,11 @@ static void hist_trigger_print_key(struct seq_file *m, } else if (key_field->flags & HIST_FIELD_FL_LOG2) { seq_printf(m, "%s: ~ 2^%-2llu", field_name, *(u64 *)(key + key_field->offset)); + } else if (key_field->flags & HIST_FIELD_FL_BUCKET) { + unsigned long buckets = key_field->buckets; + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: ~ %llu-%llu", field_name, + uval, uval + buckets -1); } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", field_name, (char *)(key + key_field->offset)); @@ -5137,6 +5230,8 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) seq_printf(m, ".%s", flags); } } + if (hist_field->buckets) + seq_printf(m, "=%ld", hist_field->buckets); } static int event_hist_trigger_print(struct seq_file *m, diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 9315fc03e303..d54094b7a9d7 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1298,7 +1298,7 @@ static int __create_synth_event(const char *name, const char *raw_fields) } ret = register_synth_event(event); if (!ret) - dyn_event_add(&event->devent); + dyn_event_add(&event->devent, &event->call); else free_synth_event(event); out: @@ -1369,13 +1369,15 @@ static int destroy_synth_event(struct synth_event *se) int ret; if (se->ref) - ret = -EBUSY; - else { - ret = unregister_synth_event(se); - if (!ret) { - dyn_event_remove(&se->devent); - free_synth_event(se); - } + return -EBUSY; + + if (trace_event_dyn_busy(&se->call)) + return -EBUSY; + + ret = unregister_synth_event(se); + if (!ret) { + dyn_event_remove(&se->devent); + free_synth_event(se); } return ret; @@ -2102,6 +2104,9 @@ static int synth_event_release(struct dyn_event *ev) if (event->ref) return -EBUSY; + if (trace_event_dyn_busy(&event->call)) + return -EBUSY; + ret = unregister_synth_event(event); if (ret) return ret; diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index cf84d0f6583a..3d5c07239a2a 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -124,6 +124,18 @@ static void *trigger_next(struct seq_file *m, void *t, loff_t *pos) return seq_list_next(t, &event_file->triggers, pos); } +static bool check_user_trigger(struct trace_event_file *file) +{ + struct event_trigger_data *data; + + list_for_each_entry_rcu(data, &file->triggers, list) { + if (data->flags & EVENT_TRIGGER_FL_PROBE) + continue; + return true; + } + return false; +} + static void *trigger_start(struct seq_file *m, loff_t *pos) { struct trace_event_file *event_file; @@ -134,7 +146,7 @@ static void *trigger_start(struct seq_file *m, loff_t *pos) if (unlikely(!event_file)) return ERR_PTR(-ENODEV); - if (list_empty(&event_file->triggers)) + if (list_empty(&event_file->triggers) || !check_user_trigger(event_file)) return *pos == 0 ? SHOW_AVAILABLE_TRIGGERS : NULL; return seq_list_start(&event_file->triggers, *pos); @@ -1334,7 +1346,7 @@ void event_enable_trigger_free(struct event_trigger_ops *ops, if (!data->ref) { /* Remove the SOFT_MODE flag */ trace_event_enable_disable(enable_data->file, 0, 1); - module_put(enable_data->file->event_call->mod); + trace_event_put_ref(enable_data->file->event_call); trigger_data_free(data); kfree(enable_data); } @@ -1481,7 +1493,7 @@ int event_enable_trigger_func(struct event_command *cmd_ops, out_reg: /* Don't let event modules unload while probe registered */ - ret = try_module_get(event_enable_file->event_call->mod); + ret = trace_event_try_get_ref(event_enable_file->event_call); if (!ret) { ret = -EBUSY; goto out_free; @@ -1510,7 +1522,7 @@ int event_enable_trigger_func(struct event_command *cmd_ops, out_disable: trace_event_enable_disable(event_enable_file, 0, 1); out_put: - module_put(event_enable_file->event_call->mod); + trace_event_put_ref(event_enable_file->event_call); out_free: if (cmd_ops->set_filter) cmd_ops->set_filter(NULL, trigger_data, NULL); diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index 14f46aae1981..1b83d75eb103 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -325,10 +325,10 @@ static void move_to_next_cpu(void) if (!cpumask_equal(current_mask, current->cpus_ptr)) goto change_mode; - get_online_cpus(); + cpus_read_lock(); cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask); next_cpu = cpumask_next(raw_smp_processor_id(), current_mask); - put_online_cpus(); + cpus_read_unlock(); if (next_cpu >= nr_cpu_ids) next_cpu = cpumask_first(current_mask); @@ -398,7 +398,7 @@ static void stop_single_kthread(void) struct hwlat_kthread_data *kdata = get_cpu_data(); struct task_struct *kthread; - get_online_cpus(); + cpus_read_lock(); kthread = kdata->kthread; if (!kthread) @@ -408,7 +408,7 @@ static void stop_single_kthread(void) kdata->kthread = NULL; out_put_cpus: - put_online_cpus(); + cpus_read_unlock(); } @@ -425,14 +425,14 @@ static int start_single_kthread(struct trace_array *tr) struct task_struct *kthread; int next_cpu; - get_online_cpus(); + cpus_read_lock(); if (kdata->kthread) goto out_put_cpus; kthread = kthread_create(kthread_fn, NULL, "hwlatd"); if (IS_ERR(kthread)) { pr_err(BANNER "could not start sampling thread\n"); - put_online_cpus(); + cpus_read_unlock(); return -ENOMEM; } @@ -452,7 +452,7 @@ static int start_single_kthread(struct trace_array *tr) wake_up_process(kthread); out_put_cpus: - put_online_cpus(); + cpus_read_unlock(); return 0; } @@ -479,10 +479,10 @@ static void stop_per_cpu_kthreads(void) { unsigned int cpu; - get_online_cpus(); + cpus_read_lock(); for_each_online_cpu(cpu) stop_cpu_kthread(cpu); - put_online_cpus(); + cpus_read_unlock(); } /* @@ -515,7 +515,7 @@ static void hwlat_hotplug_workfn(struct work_struct *dummy) mutex_lock(&trace_types_lock); mutex_lock(&hwlat_data.lock); - get_online_cpus(); + cpus_read_lock(); if (!hwlat_busy || hwlat_data.thread_mode != MODE_PER_CPU) goto out_unlock; @@ -526,7 +526,7 @@ static void hwlat_hotplug_workfn(struct work_struct *dummy) start_cpu_kthread(cpu); out_unlock: - put_online_cpus(); + cpus_read_unlock(); mutex_unlock(&hwlat_data.lock); mutex_unlock(&trace_types_lock); } @@ -582,7 +582,7 @@ static int start_per_cpu_kthreads(struct trace_array *tr) unsigned int cpu; int retval; - get_online_cpus(); + cpus_read_lock(); /* * Run only on CPUs in which hwlat is allowed to run. */ @@ -596,12 +596,12 @@ static int start_per_cpu_kthreads(struct trace_array *tr) if (retval) goto out_error; } - put_online_cpus(); + cpus_read_unlock(); return 0; out_error: - put_online_cpus(); + cpus_read_unlock(); stop_per_cpu_kthreads(); return retval; } diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 9da76104f7a2..59857a1ee44c 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -147,11 +147,17 @@ static int kdb_ftdump(int argc, const char **argv) return 0; } +static kdbtab_t ftdump_cmd = { + .name = "ftdump", + .func = kdb_ftdump, + .usage = "[skip_#entries] [cpu]", + .help = "Dump ftrace log; -skip dumps last #entries", + .flags = KDB_ENABLE_ALWAYS_SAFE, +}; + static __init int kdb_ftrace_register(void) { - kdb_register_flags("ftdump", kdb_ftdump, "[skip_#entries] [cpu]", - "Dump ftrace log; -skip dumps last #entries", 0, - KDB_ENABLE_ALWAYS_SAFE); + kdb_register(&ftdump_cmd); return 0; } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index ea6178cb5e33..3a64ba4bbad6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -80,10 +80,6 @@ static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) for_each_dyn_event(dpos) \ if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) -#define SIZEOF_TRACE_KPROBE(n) \ - (offsetof(struct trace_kprobe, tp.args) + \ - (sizeof(struct probe_arg) * (n))) - static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) { return tk->rp.handler != NULL; @@ -265,7 +261,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group, struct trace_kprobe *tk; int ret = -ENOMEM; - tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); + tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL); if (!tk) return ERR_PTR(ret); @@ -543,6 +539,10 @@ static int unregister_trace_kprobe(struct trace_kprobe *tk) if (trace_probe_is_enabled(&tk->tp)) return -EBUSY; + /* If there's a reference to the dynamic event */ + if (trace_event_dyn_busy(trace_probe_event_call(&tk->tp))) + return -EBUSY; + /* Will fail if probe is being used by ftrace or perf */ if (unregister_kprobe_event(tk)) return -EBUSY; @@ -618,7 +618,7 @@ static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to) if (ret) trace_probe_unlink(&tk->tp); else - dyn_event_add(&tk->devent); + dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp)); return ret; } @@ -647,7 +647,11 @@ static int register_trace_kprobe(struct trace_kprobe *tk) /* Register new event */ ret = register_kprobe_event(tk); if (ret) { - pr_warn("Failed to register probe event(%d)\n", ret); + if (ret == -EEXIST) { + trace_probe_log_set_index(0); + trace_probe_log_err(0, EVENT_EXIST); + } else + pr_warn("Failed to register probe event(%d)\n", ret); goto end; } @@ -661,7 +665,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk) if (ret < 0) unregister_kprobe_event(tk); else - dyn_event_add(&tk->devent); + dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp)); end: mutex_unlock(&event_mutex); @@ -703,14 +707,6 @@ static struct notifier_block trace_kprobe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; -/* Convert certain expected symbols into '_' when generating event names */ -static inline void sanitize_event_name(char *name) -{ - while (*name++ != '\0') - if (*name == ':' || *name == '.') - *name = '_'; -} - static int __trace_kprobe_create(int argc, const char *argv[]) { /* @@ -742,6 +738,7 @@ static int __trace_kprobe_create(int argc, const char *argv[]) bool is_return = false; char *symbol = NULL, *tmp = NULL; const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; + enum probe_print_type ptype; int maxactive = 0; long offset = 0; void *addr = NULL; @@ -869,20 +866,14 @@ static int __trace_kprobe_create(int argc, const char *argv[]) /* parse arguments */ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { - tmp = kstrdup(argv[i], GFP_KERNEL); - if (!tmp) { - ret = -ENOMEM; - goto error; - } - trace_probe_log_set_index(i + 2); - ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); - kfree(tmp); + ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], flags); if (ret) goto error; /* This can be -ENOMEM */ } - ret = traceprobe_set_print_fmt(&tk->tp, is_return); + ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; + ret = traceprobe_set_print_fmt(&tk->tp, ptype); if (ret < 0) goto error; @@ -1330,9 +1321,10 @@ probe_mem_read(void *dest, void *src, size_t size) /* Note that we don't verify it, since the code does not come from user space */ static int -process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, +process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, void *base) { + struct pt_regs *regs = rec; unsigned long val; retry: @@ -1806,6 +1798,7 @@ struct trace_event_call * create_local_trace_kprobe(char *func, void *addr, unsigned long offs, bool is_return) { + enum probe_print_type ptype; struct trace_kprobe *tk; int ret; char *event; @@ -1829,7 +1822,9 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, init_trace_event_call(tk); - if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { + ptype = trace_kprobe_is_return(tk) ? + PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; + if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) { ret = -ENOMEM; goto error; } diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index b61eefe5ccf5..ce053619f289 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -1498,12 +1498,12 @@ static void stop_per_cpu_kthreads(void) { int cpu; - get_online_cpus(); + cpus_read_lock(); for_each_online_cpu(cpu) stop_kthread(cpu); - put_online_cpus(); + cpus_read_unlock(); } /* @@ -1548,10 +1548,10 @@ static int start_kthread(unsigned int cpu) static int start_per_cpu_kthreads(struct trace_array *tr) { struct cpumask *current_mask = &save_cpumask; - int retval; + int retval = 0; int cpu; - get_online_cpus(); + cpus_read_lock(); /* * Run only on CPUs in which trace and osnoise are allowed to run. */ @@ -1568,13 +1568,13 @@ static int start_per_cpu_kthreads(struct trace_array *tr) retval = start_kthread(cpu); if (retval) { stop_per_cpu_kthreads(); - return retval; + break; } } - put_online_cpus(); + cpus_read_unlock(); - return 0; + return retval; } #ifdef CONFIG_HOTPLUG_CPU @@ -1590,7 +1590,7 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy) goto out_unlock_trace; mutex_lock(&interface_lock); - get_online_cpus(); + cpus_read_lock(); if (!cpumask_test_cpu(cpu, &osnoise_cpumask)) goto out_unlock; @@ -1601,7 +1601,7 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy) start_kthread(cpu); out_unlock: - put_online_cpus(); + cpus_read_unlock(); mutex_unlock(&interface_lock); out_unlock_trace: mutex_unlock(&trace_types_lock); @@ -1743,11 +1743,11 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count, /* * osnoise_cpumask is read by CPU hotplug operations. */ - get_online_cpus(); + cpus_read_lock(); cpumask_copy(&osnoise_cpumask, osnoise_cpumask_new); - put_online_cpus(); + cpus_read_unlock(); mutex_unlock(&interface_lock); if (running) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index a0bf446bb034..c2ca40e8595b 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -492,8 +492,13 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry) trace_seq_printf(s, "%c%c%c", irqs_off, need_resched, hardsoft_irq); - if (entry->preempt_count) - trace_seq_printf(s, "%x", entry->preempt_count); + if (entry->preempt_count & 0xf) + trace_seq_printf(s, "%x", entry->preempt_count & 0xf); + else + trace_seq_putc(s, '.'); + + if (entry->preempt_count & 0xf0) + trace_seq_printf(s, "%x", entry->preempt_count >> 4); else trace_seq_putc(s, '.'); @@ -656,7 +661,7 @@ int trace_print_lat_context(struct trace_iterator *iter) trace_seq_printf( s, "%16s %7d %3d %d %08x %08lx ", comm, entry->pid, iter->cpu, entry->flags, - entry->preempt_count, iter->idx); + entry->preempt_count & 0xf, iter->idx); } else { lat_print_generic(s, entry, iter->cpu); } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 15413ad7cef2..3ed2a3f37297 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -233,6 +233,9 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, int len; slash = strchr(event, '/'); + if (!slash) + slash = strchr(event, '.'); + if (slash) { if (slash == event) { trace_probe_log_err(offset, NO_GROUP_NAME); @@ -316,6 +319,13 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, code->op = FETCH_OP_ARG; code->param = (unsigned int)param - 1; #endif + } else if (flags & TPARG_FL_TPOINT) { + if (code->data) + return -EFAULT; + code->data = kstrdup(arg, GFP_KERNEL); + if (!code->data) + return -ENOMEM; + code->op = FETCH_OP_TP_ARG; } else goto inval_var; @@ -540,26 +550,34 @@ static int __parse_bitfield_probe_arg(const char *bf, } /* String length checking wrapper */ -static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, +static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, struct probe_arg *parg, unsigned int flags, int offset) { struct fetch_insn *code, *scode, *tmp = NULL; char *t, *t2, *t3; + char *arg; int ret, len; + arg = kstrdup(argv, GFP_KERNEL); + if (!arg) + return -ENOMEM; + + ret = -EINVAL; len = strlen(arg); if (len > MAX_ARGSTR_LEN) { trace_probe_log_err(offset, ARG_TOO_LONG); - return -EINVAL; + goto out; } else if (len == 0) { trace_probe_log_err(offset, NO_ARG_BODY); - return -EINVAL; + goto out; } + ret = -ENOMEM; parg->comm = kstrdup(arg, GFP_KERNEL); if (!parg->comm) - return -ENOMEM; + goto out; + ret = -EINVAL; t = strchr(arg, ':'); if (t) { *t = '\0'; @@ -571,22 +589,22 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, offset += t2 + strlen(t2) - arg; trace_probe_log_err(offset, ARRAY_NO_CLOSE); - return -EINVAL; + goto out; } else if (t3[1] != '\0') { trace_probe_log_err(offset + t3 + 1 - arg, BAD_ARRAY_SUFFIX); - return -EINVAL; + goto out; } *t3 = '\0'; if (kstrtouint(t2, 0, &parg->count) || !parg->count) { trace_probe_log_err(offset + t2 - arg, BAD_ARRAY_NUM); - return -EINVAL; + goto out; } if (parg->count > MAX_ARRAY_LEN) { trace_probe_log_err(offset + t2 - arg, ARRAY_TOO_BIG); - return -EINVAL; + goto out; } } } @@ -598,29 +616,30 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) { /* The type of $comm must be "string", and not an array. */ if (parg->count || (t && strcmp(t, "string"))) - return -EINVAL; + goto out; parg->type = find_fetch_type("string"); } else parg->type = find_fetch_type(t); if (!parg->type) { trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE); - return -EINVAL; + goto out; } parg->offset = *size; *size += parg->type->size * (parg->count ?: 1); + ret = -ENOMEM; if (parg->count) { len = strlen(parg->type->fmttype) + 6; parg->fmt = kmalloc(len, GFP_KERNEL); if (!parg->fmt) - return -ENOMEM; + goto out; snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, parg->count); } code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); if (!code) - return -ENOMEM; + goto out; code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], @@ -628,19 +647,20 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, if (ret) goto fail; + ret = -EINVAL; /* Store operation */ if (!strcmp(parg->type->name, "string") || !strcmp(parg->type->name, "ustring")) { if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && - code->op != FETCH_OP_DATA) { + code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_STRING); - ret = -EINVAL; goto fail; } if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || - code->op == FETCH_OP_DATA) || parg->count) { + code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || + parg->count) { /* * IMM, DATA and COMM is pointing actual address, those * must be kept, and if parg->count != 0, this is an @@ -650,7 +670,6 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, code++; if (code->op != FETCH_OP_NOP) { trace_probe_log_err(offset, TOO_MANY_OPS); - ret = -EINVAL; goto fail; } } @@ -672,7 +691,6 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, code++; if (code->op != FETCH_OP_NOP) { trace_probe_log_err(offset, TOO_MANY_OPS); - ret = -EINVAL; goto fail; } code->op = FETCH_OP_ST_RAW; @@ -687,6 +705,7 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, goto fail; } } + ret = -EINVAL; /* Loop(Array) operation */ if (parg->count) { if (scode->op != FETCH_OP_ST_MEM && @@ -694,13 +713,11 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, scode->op != FETCH_OP_ST_USTRING) { trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_STRING); - ret = -EINVAL; goto fail; } code++; if (code->op != FETCH_OP_NOP) { trace_probe_log_err(offset, TOO_MANY_OPS); - ret = -EINVAL; goto fail; } code->op = FETCH_OP_LP_ARRAY; @@ -709,6 +726,7 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, code++; code->op = FETCH_OP_END; + ret = 0; /* Shrink down the code buffer */ parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); if (!parg->code) @@ -724,6 +742,8 @@ fail: kfree(code->data); } kfree(tmp); +out: + kfree(arg); return ret; } @@ -745,11 +765,11 @@ static int traceprobe_conflict_field_name(const char *name, return 0; } -int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg, +int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, unsigned int flags) { struct probe_arg *parg = &tp->args[i]; - char *body; + const char *body; /* Increment count for freeing args in error case */ tp->nr_args++; @@ -839,19 +859,29 @@ int traceprobe_update_arg(struct probe_arg *arg) /* When len=0, we just calculate the needed length */ #define LEN_OR_ZERO (len ? len - pos : 0) static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, - bool is_return) + enum probe_print_type ptype) { struct probe_arg *parg; int i, j; int pos = 0; const char *fmt, *arg; - if (!is_return) { + switch (ptype) { + case PROBE_PRINT_NORMAL: fmt = "(%lx)"; arg = "REC->" FIELD_STRING_IP; - } else { + break; + case PROBE_PRINT_RETURN: fmt = "(%lx <- %lx)"; arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; + break; + case PROBE_PRINT_EVENT: + fmt = "(%u)"; + arg = "REC->" FIELD_STRING_TYPE; + break; + default: + WARN_ON_ONCE(1); + return 0; } pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); @@ -900,20 +930,20 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, } #undef LEN_OR_ZERO -int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) +int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) { struct trace_event_call *call = trace_probe_event_call(tp); int len; char *print_fmt; /* First: called with 0 length to calculate the needed length */ - len = __set_print_fmt(tp, NULL, 0, is_return); + len = __set_print_fmt(tp, NULL, 0, ptype); print_fmt = kmalloc(len + 1, GFP_KERNEL); if (!print_fmt) return -ENOMEM; /* Second: actually write the @print_fmt */ - __set_print_fmt(tp, print_fmt, len + 1, is_return); + __set_print_fmt(tp, print_fmt, len + 1, ptype); call->print_fmt = print_fmt; return 0; @@ -1029,11 +1059,36 @@ error: return ret; } +static struct trace_event_call * +find_trace_event_call(const char *system, const char *event_name) +{ + struct trace_event_call *tp_event; + const char *name; + + list_for_each_entry(tp_event, &ftrace_events, list) { + if (!tp_event->class->system || + strcmp(system, tp_event->class->system)) + continue; + name = trace_event_name(tp_event); + if (!name || strcmp(event_name, name)) + continue; + return tp_event; + } + + return NULL; +} + int trace_probe_register_event_call(struct trace_probe *tp) { struct trace_event_call *call = trace_probe_event_call(tp); int ret; + lockdep_assert_held(&event_mutex); + + if (find_trace_event_call(trace_probe_group_name(tp), + trace_probe_name(tp))) + return -EEXIST; + ret = register_trace_event(&call->event); if (!ret) return -ENODEV; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 227d518e5ba5..99e7a5df025e 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -38,6 +38,7 @@ #define FIELD_STRING_IP "__probe_ip" #define FIELD_STRING_RETIP "__probe_ret_ip" #define FIELD_STRING_FUNC "__probe_func" +#define FIELD_STRING_TYPE "__probe_type" #undef DEFINE_FIELD #define DEFINE_FIELD(type, item, name, is_signed) \ @@ -102,6 +103,7 @@ enum fetch_op { FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ // Stage 5 (loop) op FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ + FETCH_OP_TP_ARG, /* Trace Point argument */ FETCH_OP_END, FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */ }; @@ -351,10 +353,11 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char #define TPARG_FL_RETURN BIT(0) #define TPARG_FL_KERNEL BIT(1) #define TPARG_FL_FENTRY BIT(2) -#define TPARG_FL_MASK GENMASK(2, 0) +#define TPARG_FL_TPOINT BIT(3) +#define TPARG_FL_MASK GENMASK(3, 0) extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, - char *arg, unsigned int flags); + const char *argv, unsigned int flags); extern int traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg); @@ -363,7 +366,13 @@ extern int traceprobe_split_symbol_offset(char *symbol, long *offset); int traceprobe_parse_event_name(const char **pevent, const char **pgroup, char *buf, int offset); -extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return); +enum probe_print_type { + PROBE_PRINT_NORMAL, + PROBE_PRINT_RETURN, + PROBE_PRINT_EVENT, +}; + +extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype); #ifdef CONFIG_PERF_EVENTS extern struct trace_event_call * @@ -399,6 +408,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(NO_EVENT_NAME, "Event name is not specified"), \ C(EVENT_TOO_LONG, "Event name is too long"), \ C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \ + C(EVENT_EXIST, "Given group/event name is already used by another event"), \ C(RETVAL_ON_PROBE, "$retval is not available on probe"), \ C(BAD_STACK_NUM, "Invalid stack number"), \ C(BAD_ARG_NUM, "Invalid argument number"), \ diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index f003c5d02a3a..b3bdb8ddb862 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -54,7 +54,7 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf) * If dest is NULL, don't store result and return required dynamic data size. */ static int -process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, +process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, void *base); static nokprobe_inline int fetch_store_strlen(unsigned long addr); static nokprobe_inline int @@ -188,7 +188,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs) /* Store the value of each argument */ static nokprobe_inline void -store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs, +store_trace_args(void *data, struct trace_probe *tp, void *rec, int header_size, int maxlen) { struct probe_arg *arg; @@ -203,7 +203,7 @@ store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs, /* Point the dynamic data area if needed */ if (unlikely(arg->dynamic)) *dl = make_data_loc(maxlen, dyndata - base); - ret = process_fetch_insn(arg->code, regs, dl, base); + ret = process_fetch_insn(arg->code, rec, dl, base); if (unlikely(ret < 0 && arg->dynamic)) { *dl = make_data_loc(0, dyndata - base); } else { diff --git a/kernel/trace/trace_synth.h b/kernel/trace/trace_synth.h index 4007fe95cf42..b29595fe3ac5 100644 --- a/kernel/trace/trace_synth.h +++ b/kernel/trace/trace_synth.h @@ -5,7 +5,7 @@ #include "trace_dynevent.h" #define SYNTH_SYSTEM "synthetic" -#define SYNTH_FIELDS_MAX 32 +#define SYNTH_FIELDS_MAX 64 #define STR_VAR_LEN_MAX MAX_FILTER_STR_VAL /* must be multiple of sizeof(u64) */ diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 9b50869a5ddb..225ce569bf8f 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -83,10 +83,6 @@ static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) for_each_dyn_event(dpos) \ if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) -#define SIZEOF_TRACE_UPROBE(n) \ - (offsetof(struct trace_uprobe, tp.args) + \ - (sizeof(struct probe_arg) * (n))) - static int register_uprobe_event(struct trace_uprobe *tu); static int unregister_uprobe_event(struct trace_uprobe *tu); @@ -217,9 +213,10 @@ static unsigned long translate_user_vaddr(unsigned long file_offset) /* Note that we don't verify it, since the code does not come from user space */ static int -process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, +process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, void *base) { + struct pt_regs *regs = rec; unsigned long val; /* 1st stage: get value from context */ @@ -340,7 +337,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) struct trace_uprobe *tu; int ret; - tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); + tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); if (!tu) return ERR_PTR(-ENOMEM); @@ -393,6 +390,10 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu) if (trace_probe_has_sibling(&tu->tp)) goto unreg; + /* If there's a reference to the dynamic event */ + if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) + return -EBUSY; + ret = unregister_uprobe_event(tu); if (ret) return ret; @@ -455,7 +456,7 @@ static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) /* Append to existing event */ ret = trace_probe_append(&tu->tp, &to->tp); if (!ret) - dyn_event_add(&tu->devent); + dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); return ret; } @@ -514,11 +515,15 @@ static int register_trace_uprobe(struct trace_uprobe *tu) ret = register_uprobe_event(tu); if (ret) { - pr_warn("Failed to register probe event(%d)\n", ret); + if (ret == -EEXIST) { + trace_probe_log_set_index(0); + trace_probe_log_err(0, EVENT_EXIST); + } else + pr_warn("Failed to register probe event(%d)\n", ret); goto end; } - dyn_event_add(&tu->devent); + dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); end: mutex_unlock(&event_mutex); @@ -536,6 +541,7 @@ static int __trace_uprobe_create(int argc, const char **argv) const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; char *arg, *filename, *rctr, *rctr_end, *tmp; char buf[MAX_EVENT_NAME_LEN]; + enum probe_print_type ptype; struct path path; unsigned long offset, ref_ctr_offset; bool is_return = false; @@ -680,21 +686,15 @@ static int __trace_uprobe_create(int argc, const char **argv) /* parse arguments */ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { - tmp = kstrdup(argv[i], GFP_KERNEL); - if (!tmp) { - ret = -ENOMEM; - goto error; - } - trace_probe_log_set_index(i + 2); - ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp, + ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], is_return ? TPARG_FL_RETURN : 0); - kfree(tmp); if (ret) goto error; } - ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)); + ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; + ret = traceprobe_set_print_fmt(&tu->tp, ptype); if (ret < 0) goto error; @@ -1585,6 +1585,7 @@ struct trace_event_call * create_local_trace_uprobe(char *name, unsigned long offs, unsigned long ref_ctr_offset, bool is_return) { + enum probe_print_type ptype; struct trace_uprobe *tu; struct path path; int ret; @@ -1619,7 +1620,8 @@ create_local_trace_uprobe(char *name, unsigned long offs, tu->filename = kstrdup(name, GFP_KERNEL); init_trace_event_call(tu); - if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { + ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; + if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) { ret = -ENOMEM; goto error; } diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index efd14c79fab4..64ea283f2f86 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -577,7 +577,7 @@ bool trace_module_has_bad_taint(struct module *mod) static BLOCKING_NOTIFIER_HEAD(tracepoint_notify_list); /** - * register_tracepoint_notifier - register tracepoint coming/going notifier + * register_tracepoint_module_notifier - register tracepoint coming/going notifier * @nb: notifier block * * Notifiers registered with this function are called on module @@ -603,7 +603,7 @@ end: EXPORT_SYMBOL_GPL(register_tracepoint_module_notifier); /** - * unregister_tracepoint_notifier - unregister tracepoint coming/going notifier + * unregister_tracepoint_module_notifier - unregister tracepoint coming/going notifier * @nb: notifier block * * The notifier block callback should expect a "struct tp_module" data diff --git a/kernel/ucount.c b/kernel/ucount.c index bb51849e6375..eb03f3c68375 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -284,6 +284,55 @@ bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v) return (new == 0); } +static void do_dec_rlimit_put_ucounts(struct ucounts *ucounts, + struct ucounts *last, enum ucount_type type) +{ + struct ucounts *iter, *next; + for (iter = ucounts; iter != last; iter = next) { + long dec = atomic_long_add_return(-1, &iter->ucount[type]); + WARN_ON_ONCE(dec < 0); + next = iter->ns->ucounts; + if (dec == 0) + put_ucounts(iter); + } +} + +void dec_rlimit_put_ucounts(struct ucounts *ucounts, enum ucount_type type) +{ + do_dec_rlimit_put_ucounts(ucounts, NULL, type); +} + +long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type) +{ + /* Caller must hold a reference to ucounts */ + struct ucounts *iter; + long dec, ret = 0; + + for (iter = ucounts; iter; iter = iter->ns->ucounts) { + long max = READ_ONCE(iter->ns->ucount_max[type]); + long new = atomic_long_add_return(1, &iter->ucount[type]); + if (new < 0 || new > max) + goto unwind; + if (iter == ucounts) + ret = new; + /* + * Grab an extra ucount reference for the caller when + * the rlimit count was previously 0. + */ + if (new != 1) + continue; + if (!get_ucounts(iter)) + goto dec_unwind; + } + return ret; +dec_unwind: + dec = atomic_long_add_return(-1, &iter->ucount[type]); + WARN_ON_ONCE(dec < 0); +unwind: + do_dec_rlimit_put_ucounts(ucounts, iter, type); + return 0; +} + bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max) { struct ucounts *iter; diff --git a/kernel/user.c b/kernel/user.c index c82399c1618a..e2cf8c22b539 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -129,6 +129,22 @@ static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent) return NULL; } +static int user_epoll_alloc(struct user_struct *up) +{ +#ifdef CONFIG_EPOLL + return percpu_counter_init(&up->epoll_watches, 0, GFP_KERNEL); +#else + return 0; +#endif +} + +static void user_epoll_free(struct user_struct *up) +{ +#ifdef CONFIG_EPOLL + percpu_counter_destroy(&up->epoll_watches); +#endif +} + /* IRQs are disabled and uidhash_lock is held upon function entry. * IRQ state (as stored in flags) is restored and uidhash_lock released * upon function exit. @@ -138,6 +154,7 @@ static void free_user(struct user_struct *up, unsigned long flags) { uid_hash_remove(up); spin_unlock_irqrestore(&uidhash_lock, flags); + user_epoll_free(up); kmem_cache_free(uid_cachep, up); } @@ -185,6 +202,10 @@ struct user_struct *alloc_uid(kuid_t uid) new->uid = uid; refcount_set(&new->__count, 1); + if (user_epoll_alloc(new)) { + kmem_cache_free(uid_cachep, new); + return NULL; + } ratelimit_state_init(&new->ratelimit, HZ, 100); ratelimit_set_flags(&new->ratelimit, RATELIMIT_MSG_ON_RELEASE); @@ -195,6 +216,7 @@ struct user_struct *alloc_uid(kuid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { + user_epoll_free(new); kmem_cache_free(uid_cachep, new); } else { uid_hash_insert(new, hashent); @@ -216,6 +238,9 @@ static int __init uid_cache_init(void) for(n = 0; n < UIDHASH_SZ; ++n) INIT_HLIST_HEAD(uidhash_table + n); + if (user_epoll_alloc(&root_user)) + panic("root_user epoll percpu counter alloc failed"); + /* Insert the root user immediately (init already runs as root) */ spin_lock_irq(&uidhash_lock); uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID)); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index ef82d401dde8..6b2e3ca7ee99 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -1385,7 +1385,7 @@ const struct proc_ns_operations userns_operations = { static __init int user_namespaces_init(void) { - user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC); + user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC | SLAB_ACCOUNT); return 0; } subsys_initcall(user_namespaces_init); diff --git a/kernel/workqueue.c b/kernel/workqueue.c index f148eacda55a..1b3eb1e9531f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -205,9 +205,26 @@ struct pool_workqueue { int refcnt; /* L: reference count */ int nr_in_flight[WORK_NR_COLORS]; /* L: nr of in_flight works */ + + /* + * nr_active management and WORK_STRUCT_INACTIVE: + * + * When pwq->nr_active >= max_active, new work item is queued to + * pwq->inactive_works instead of pool->worklist and marked with + * WORK_STRUCT_INACTIVE. + * + * All work items marked with WORK_STRUCT_INACTIVE do not participate + * in pwq->nr_active and all work items in pwq->inactive_works are + * marked with WORK_STRUCT_INACTIVE. But not all WORK_STRUCT_INACTIVE + * work items are in pwq->inactive_works. Some of them are ready to + * run in pool->worklist or worker->scheduled. Those work itmes are + * only struct wq_barrier which is used for flush_work() and should + * not participate in pwq->nr_active. For non-barrier work item, it + * is marked with WORK_STRUCT_INACTIVE iff it is in pwq->inactive_works. + */ int nr_active; /* L: nr of active works */ int max_active; /* L: max active works */ - struct list_head delayed_works; /* L: delayed works */ + struct list_head inactive_works; /* L: inactive works */ struct list_head pwqs_node; /* WR: node on wq->pwqs */ struct list_head mayday_node; /* MD: node on wq->maydays */ @@ -524,7 +541,7 @@ static inline void debug_work_deactivate(struct work_struct *work) { } #endif /** - * worker_pool_assign_id - allocate ID and assing it to @pool + * worker_pool_assign_id - allocate ID and assign it to @pool * @pool: the pool pointer of interest * * Returns 0 if ID in [0, WORK_OFFQ_POOL_NONE) is allocated and assigned @@ -579,9 +596,9 @@ static unsigned int work_color_to_flags(int color) return color << WORK_STRUCT_COLOR_SHIFT; } -static int get_work_color(struct work_struct *work) +static int get_work_color(unsigned long work_data) { - return (*work_data_bits(work) >> WORK_STRUCT_COLOR_SHIFT) & + return (work_data >> WORK_STRUCT_COLOR_SHIFT) & ((1 << WORK_STRUCT_COLOR_BITS) - 1); } @@ -1136,7 +1153,7 @@ static void put_pwq_unlocked(struct pool_workqueue *pwq) } } -static void pwq_activate_delayed_work(struct work_struct *work) +static void pwq_activate_inactive_work(struct work_struct *work) { struct pool_workqueue *pwq = get_work_pwq(work); @@ -1144,22 +1161,22 @@ static void pwq_activate_delayed_work(struct work_struct *work) if (list_empty(&pwq->pool->worklist)) pwq->pool->watchdog_ts = jiffies; move_linked_works(work, &pwq->pool->worklist, NULL); - __clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work)); + __clear_bit(WORK_STRUCT_INACTIVE_BIT, work_data_bits(work)); pwq->nr_active++; } -static void pwq_activate_first_delayed(struct pool_workqueue *pwq) +static void pwq_activate_first_inactive(struct pool_workqueue *pwq) { - struct work_struct *work = list_first_entry(&pwq->delayed_works, + struct work_struct *work = list_first_entry(&pwq->inactive_works, struct work_struct, entry); - pwq_activate_delayed_work(work); + pwq_activate_inactive_work(work); } /** * pwq_dec_nr_in_flight - decrement pwq's nr_in_flight * @pwq: pwq of interest - * @color: color of work which left the queue + * @work_data: work_data of work which left the queue * * A work either has completed or is removed from pending queue, * decrement nr_in_flight of its pwq and handle workqueue flushing. @@ -1167,21 +1184,21 @@ static void pwq_activate_first_delayed(struct pool_workqueue *pwq) * CONTEXT: * raw_spin_lock_irq(pool->lock). */ -static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, int color) +static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, unsigned long work_data) { - /* uncolored work items don't participate in flushing or nr_active */ - if (color == WORK_NO_COLOR) - goto out_put; - - pwq->nr_in_flight[color]--; + int color = get_work_color(work_data); - pwq->nr_active--; - if (!list_empty(&pwq->delayed_works)) { - /* one down, submit a delayed one */ - if (pwq->nr_active < pwq->max_active) - pwq_activate_first_delayed(pwq); + if (!(work_data & WORK_STRUCT_INACTIVE)) { + pwq->nr_active--; + if (!list_empty(&pwq->inactive_works)) { + /* one down, submit an inactive one */ + if (pwq->nr_active < pwq->max_active) + pwq_activate_first_inactive(pwq); + } } + pwq->nr_in_flight[color]--; + /* is flush in progress and are we at the flushing tip? */ if (likely(pwq->flush_color != color)) goto out_put; @@ -1281,17 +1298,21 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork, debug_work_deactivate(work); /* - * A delayed work item cannot be grabbed directly because - * it might have linked NO_COLOR work items which, if left - * on the delayed_list, will confuse pwq->nr_active + * A cancelable inactive work item must be in the + * pwq->inactive_works since a queued barrier can't be + * canceled (see the comments in insert_wq_barrier()). + * + * An inactive work item cannot be grabbed directly because + * it might have linked barrier work items which, if left + * on the inactive_works list, will confuse pwq->nr_active * management later on and cause stall. Make sure the work * item is activated before grabbing. */ - if (*work_data_bits(work) & WORK_STRUCT_DELAYED) - pwq_activate_delayed_work(work); + if (*work_data_bits(work) & WORK_STRUCT_INACTIVE) + pwq_activate_inactive_work(work); list_del_init(&work->entry); - pwq_dec_nr_in_flight(pwq, get_work_color(work)); + pwq_dec_nr_in_flight(pwq, *work_data_bits(work)); /* work->data points to pwq iff queued, point to pool */ set_work_pool_and_keep_pending(work, pool->id); @@ -1490,8 +1511,8 @@ retry: if (list_empty(worklist)) pwq->pool->watchdog_ts = jiffies; } else { - work_flags |= WORK_STRUCT_DELAYED; - worklist = &pwq->delayed_works; + work_flags |= WORK_STRUCT_INACTIVE; + worklist = &pwq->inactive_works; } debug_work_activate(work); @@ -1912,14 +1933,14 @@ static void worker_detach_from_pool(struct worker *worker) */ static struct worker *create_worker(struct worker_pool *pool) { - struct worker *worker = NULL; - int id = -1; + struct worker *worker; + int id; char id_buf[16]; /* ID is needed to determine kthread name */ - id = ida_simple_get(&pool->worker_ida, 0, 0, GFP_KERNEL); + id = ida_alloc(&pool->worker_ida, GFP_KERNEL); if (id < 0) - goto fail; + return NULL; worker = alloc_worker(pool->node); if (!worker) @@ -1954,8 +1975,7 @@ static struct worker *create_worker(struct worker_pool *pool) return worker; fail: - if (id >= 0) - ida_simple_remove(&pool->worker_ida, id); + ida_free(&pool->worker_ida, id); kfree(worker); return NULL; } @@ -2173,7 +2193,7 @@ __acquires(&pool->lock) struct pool_workqueue *pwq = get_work_pwq(work); struct worker_pool *pool = worker->pool; bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE; - int work_color; + unsigned long work_data; struct worker *collision; #ifdef CONFIG_LOCKDEP /* @@ -2209,7 +2229,8 @@ __acquires(&pool->lock) worker->current_work = work; worker->current_func = work->func; worker->current_pwq = pwq; - work_color = get_work_color(work); + work_data = *work_data_bits(work); + worker->current_color = get_work_color(work_data); /* * Record wq name for cmdline and debug reporting, may get @@ -2315,7 +2336,8 @@ __acquires(&pool->lock) worker->current_work = NULL; worker->current_func = NULL; worker->current_pwq = NULL; - pwq_dec_nr_in_flight(pwq, work_color); + worker->current_color = INT_MAX; + pwq_dec_nr_in_flight(pwq, work_data); } /** @@ -2378,7 +2400,7 @@ woke_up: set_pf_worker(false); set_task_comm(worker->task, "kworker/dying"); - ida_simple_remove(&pool->worker_ida, worker->id); + ida_free(&pool->worker_ida, worker->id); worker_detach_from_pool(worker); kfree(worker); return 0; @@ -2531,7 +2553,7 @@ repeat: /* * The above execution of rescued work items could * have created more to rescue through - * pwq_activate_first_delayed() or chained + * pwq_activate_first_inactive() or chained * queueing. Let's put @pwq back on mayday list so * that such back-to-back work items, which may be * being used to relieve memory pressure, don't @@ -2658,8 +2680,9 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, struct wq_barrier *barr, struct work_struct *target, struct worker *worker) { + unsigned int work_flags = 0; + unsigned int work_color; struct list_head *head; - unsigned int linked = 0; /* * debugobject calls are safe here even with pool->lock locked @@ -2674,24 +2697,31 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, barr->task = current; + /* The barrier work item does not participate in pwq->nr_active. */ + work_flags |= WORK_STRUCT_INACTIVE; + /* * If @target is currently being executed, schedule the * barrier to the worker; otherwise, put it after @target. */ - if (worker) + if (worker) { head = worker->scheduled.next; - else { + work_color = worker->current_color; + } else { unsigned long *bits = work_data_bits(target); head = target->entry.next; /* there can already be other linked works, inherit and set */ - linked = *bits & WORK_STRUCT_LINKED; + work_flags |= *bits & WORK_STRUCT_LINKED; + work_color = get_work_color(*bits); __set_bit(WORK_STRUCT_LINKED_BIT, bits); } + pwq->nr_in_flight[work_color]++; + work_flags |= work_color_to_flags(work_color); + debug_work_activate(&barr->work); - insert_work(pwq, &barr->work, head, - work_color_to_flags(WORK_NO_COLOR) | linked); + insert_work(pwq, &barr->work, head, work_flags); } /** @@ -2957,7 +2987,7 @@ reflush: bool drained; raw_spin_lock_irq(&pwq->pool->lock); - drained = !pwq->nr_active && list_empty(&pwq->delayed_works); + drained = !pwq->nr_active && list_empty(&pwq->inactive_works); raw_spin_unlock_irq(&pwq->pool->lock); if (drained) @@ -3293,7 +3323,7 @@ int schedule_on_each_cpu(work_func_t func) if (!works) return -ENOMEM; - get_online_cpus(); + cpus_read_lock(); for_each_online_cpu(cpu) { struct work_struct *work = per_cpu_ptr(works, cpu); @@ -3305,7 +3335,7 @@ int schedule_on_each_cpu(work_func_t func) for_each_online_cpu(cpu) flush_work(per_cpu_ptr(works, cpu)); - put_online_cpus(); + cpus_read_unlock(); free_percpu(works); return 0; } @@ -3713,7 +3743,7 @@ static void pwq_unbound_release_workfn(struct work_struct *work) * @pwq: target pool_workqueue * * If @pwq isn't freezing, set @pwq->max_active to the associated - * workqueue's saved_max_active and activate delayed work items + * workqueue's saved_max_active and activate inactive work items * accordingly. If @pwq is freezing, clear @pwq->max_active to zero. */ static void pwq_adjust_max_active(struct pool_workqueue *pwq) @@ -3742,9 +3772,9 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq) pwq->max_active = wq->saved_max_active; - while (!list_empty(&pwq->delayed_works) && + while (!list_empty(&pwq->inactive_works) && pwq->nr_active < pwq->max_active) { - pwq_activate_first_delayed(pwq); + pwq_activate_first_inactive(pwq); kick = true; } @@ -3763,7 +3793,7 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq) raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); } -/* initialize newly alloced @pwq which is associated with @wq and @pool */ +/* initialize newly allocated @pwq which is associated with @wq and @pool */ static void init_pwq(struct pool_workqueue *pwq, struct workqueue_struct *wq, struct worker_pool *pool) { @@ -3775,7 +3805,7 @@ static void init_pwq(struct pool_workqueue *pwq, struct workqueue_struct *wq, pwq->wq = wq; pwq->flush_color = -1; pwq->refcnt = 1; - INIT_LIST_HEAD(&pwq->delayed_works); + INIT_LIST_HEAD(&pwq->inactive_works); INIT_LIST_HEAD(&pwq->pwqs_node); INIT_LIST_HEAD(&pwq->mayday_node); INIT_WORK(&pwq->unbound_release_work, pwq_unbound_release_workfn); @@ -4016,14 +4046,14 @@ static void apply_wqattrs_commit(struct apply_wqattrs_ctx *ctx) static void apply_wqattrs_lock(void) { /* CPUs should stay stable across pwq creations and installations */ - get_online_cpus(); + cpus_read_lock(); mutex_lock(&wq_pool_mutex); } static void apply_wqattrs_unlock(void) { mutex_unlock(&wq_pool_mutex); - put_online_cpus(); + cpus_read_unlock(); } static int apply_workqueue_attrs_locked(struct workqueue_struct *wq, @@ -4068,7 +4098,7 @@ static int apply_workqueue_attrs_locked(struct workqueue_struct *wq, * * Performs GFP_KERNEL allocations. * - * Assumes caller has CPU hotplug read exclusion, i.e. get_online_cpus(). + * Assumes caller has CPU hotplug read exclusion, i.e. cpus_read_lock(). * * Return: 0 on success and -errno on failure. */ @@ -4196,7 +4226,7 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) return 0; } - get_online_cpus(); + cpus_read_lock(); if (wq->flags & __WQ_ORDERED) { ret = apply_workqueue_attrs(wq, ordered_wq_attrs[highpri]); /* there should only be single pwq for ordering guarantee */ @@ -4206,7 +4236,7 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq) } else { ret = apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]); } - put_online_cpus(); + cpus_read_unlock(); return ret; } @@ -4362,7 +4392,7 @@ static bool pwq_busy(struct pool_workqueue *pwq) if ((pwq != pwq->wq->dfl_pwq) && (pwq->refcnt > 1)) return true; - if (pwq->nr_active || !list_empty(&pwq->delayed_works)) + if (pwq->nr_active || !list_empty(&pwq->inactive_works)) return true; return false; @@ -4558,7 +4588,7 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq) else pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu)); - ret = !list_empty(&pwq->delayed_works); + ret = !list_empty(&pwq->inactive_works); preempt_enable(); rcu_read_unlock(); @@ -4754,11 +4784,11 @@ static void show_pwq(struct pool_workqueue *pwq) pr_cont("\n"); } - if (!list_empty(&pwq->delayed_works)) { + if (!list_empty(&pwq->inactive_works)) { bool comma = false; - pr_info(" delayed:"); - list_for_each_entry(work, &pwq->delayed_works, entry) { + pr_info(" inactive:"); + list_for_each_entry(work, &pwq->inactive_works, entry) { pr_cont_work(comma, work); comma = !(*work_data_bits(work) & WORK_STRUCT_LINKED); } @@ -4788,7 +4818,7 @@ void show_workqueue_state(void) bool idle = true; for_each_pwq(pwq, wq) { - if (pwq->nr_active || !list_empty(&pwq->delayed_works)) { + if (pwq->nr_active || !list_empty(&pwq->inactive_works)) { idle = false; break; } @@ -4800,8 +4830,16 @@ void show_workqueue_state(void) for_each_pwq(pwq, wq) { raw_spin_lock_irqsave(&pwq->pool->lock, flags); - if (pwq->nr_active || !list_empty(&pwq->delayed_works)) + if (pwq->nr_active || !list_empty(&pwq->inactive_works)) { + /* + * Defer printing to avoid deadlocks in console + * drivers that queue work while holding locks + * also taken in their write paths. + */ + printk_deferred_enter(); show_pwq(pwq); + printk_deferred_exit(); + } raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); /* * We could be printing a lot from atomic context, e.g. @@ -4819,7 +4857,12 @@ void show_workqueue_state(void) raw_spin_lock_irqsave(&pool->lock, flags); if (pool->nr_workers == pool->nr_idle) goto next_pool; - + /* + * Defer printing to avoid deadlocks in console drivers that + * queue work while holding locks also taken in their write + * paths. + */ + printk_deferred_enter(); pr_info("pool %d:", pool->id); pr_cont_pool_info(pool); pr_cont(" hung=%us workers=%d", @@ -4834,6 +4877,7 @@ void show_workqueue_state(void) first = false; } pr_cont("\n"); + printk_deferred_exit(); next_pool: raw_spin_unlock_irqrestore(&pool->lock, flags); /* @@ -5168,10 +5212,10 @@ long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg) { long ret = -ENODEV; - get_online_cpus(); + cpus_read_lock(); if (cpu_online(cpu)) ret = work_on_cpu(cpu, fn, arg); - put_online_cpus(); + cpus_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(work_on_cpu_safe); @@ -5183,7 +5227,7 @@ EXPORT_SYMBOL_GPL(work_on_cpu_safe); * freeze_workqueues_begin - begin freezing workqueues * * Start freezing workqueues. After this function returns, all freezable - * workqueues will queue new works to their delayed_works list instead of + * workqueues will queue new works to their inactive_works list instead of * pool->worklist. * * CONTEXT: @@ -5331,7 +5375,7 @@ static int workqueue_apply_unbound_cpumask(void) * the affinity of all unbound workqueues. This function check the @cpumask * and apply it to all unbound workqueues and updates all pwqs of them. * - * Retun: 0 - Success + * Return: 0 - Success * -EINVAL - Invalid @cpumask * -ENOMEM - Failed to allocate memory for attrs or pwqs. */ @@ -5443,7 +5487,7 @@ static ssize_t wq_pool_ids_show(struct device *dev, const char *delim = ""; int node, written = 0; - get_online_cpus(); + cpus_read_lock(); rcu_read_lock(); for_each_node(node) { written += scnprintf(buf + written, PAGE_SIZE - written, @@ -5453,7 +5497,7 @@ static ssize_t wq_pool_ids_show(struct device *dev, } written += scnprintf(buf + written, PAGE_SIZE - written, "\n"); rcu_read_unlock(); - put_online_cpus(); + cpus_read_unlock(); return written; } @@ -5902,6 +5946,13 @@ static void __init wq_numa_init(void) return; } + for_each_possible_cpu(cpu) { + if (WARN_ON(cpu_to_node(cpu) == NUMA_NO_NODE)) { + pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu); + return; + } + } + wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(); BUG_ON(!wq_update_unbound_numa_attrs_buf); @@ -5919,11 +5970,6 @@ static void __init wq_numa_init(void) for_each_possible_cpu(cpu) { node = cpu_to_node(cpu); - if (WARN_ON(node == NUMA_NO_NODE)) { - pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu); - /* happens iff arch is bonkers, let's just proceed */ - return; - } cpumask_set_cpu(cpu, tbl[node]); } diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index 498de0e909a4..e00b1204a8e9 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -30,7 +30,8 @@ struct worker { struct work_struct *current_work; /* L: work being processed */ work_func_t current_func; /* L: current_work's fn */ - struct pool_workqueue *current_pwq; /* L: current_work's pwq */ + struct pool_workqueue *current_pwq; /* L: current_work's pwq */ + unsigned int current_color; /* L: current_work's color */ struct list_head scheduled; /* L: scheduled works */ /* 64 bytes boundary on 64bit, 32 on 32bit */ |