diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/local_kptr_stash.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/local_kptr_stash.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/local_kptr_stash.c b/tools/testing/selftests/bpf/progs/local_kptr_stash.c new file mode 100644 index 000000000000..75043ffc5dad --- /dev/null +++ b/tools/testing/selftests/bpf/progs/local_kptr_stash.c @@ -0,0 +1,259 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ + +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_core_read.h> +#include "../bpf_experimental.h" +#include "../bpf_testmod/bpf_testmod_kfunc.h" + +struct node_data { + long key; + long data; + struct bpf_rb_node node; +}; + +struct refcounted_node { + long data; + struct bpf_rb_node rb_node; + struct bpf_refcount refcount; +}; + +struct stash { + struct bpf_spin_lock l; + struct refcounted_node __kptr *stashed; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, struct stash); + __uint(max_entries, 10); +} refcounted_node_stash SEC(".maps"); + +struct plain_local { + long key; + long data; +}; + +struct local_with_root { + long key; + struct bpf_spin_lock l; + struct bpf_rb_root r __contains(node_data, node); +}; + +struct map_value { + struct prog_test_ref_kfunc *not_kptr; + struct prog_test_ref_kfunc __kptr *val; + struct node_data __kptr *node; + struct plain_local __kptr *plain; + struct local_with_root __kptr *local_root; +}; + +/* This is necessary so that LLVM generates BTF for node_data struct + * If it's not included, a fwd reference for node_data will be generated but + * no struct. Example BTF of "node" field in map_value when not included: + * + * [10] PTR '(anon)' type_id=35 + * [34] FWD 'node_data' fwd_kind=struct + * [35] TYPE_TAG 'kptr_ref' type_id=34 + * + * (with no node_data struct defined) + * Had to do the same w/ bpf_kfunc_call_test_release below + */ +struct node_data *just_here_because_btf_bug; +struct refcounted_node *just_here_because_btf_bug2; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, struct map_value); + __uint(max_entries, 2); +} some_nodes SEC(".maps"); + +static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b) +{ + struct node_data *node_a; + struct node_data *node_b; + + node_a = container_of(a, struct node_data, node); + node_b = container_of(b, struct node_data, node); + + return node_a->key < node_b->key; +} + +static int create_and_stash(int idx, int val) +{ + struct map_value *mapval; + struct node_data *res; + + mapval = bpf_map_lookup_elem(&some_nodes, &idx); + if (!mapval) + return 1; + + res = bpf_obj_new(typeof(*res)); + if (!res) + return 1; + res->key = val; + + res = bpf_kptr_xchg(&mapval->node, res); + if (res) + bpf_obj_drop(res); + return 0; +} + +SEC("tc") +long stash_rb_nodes(void *ctx) +{ + return create_and_stash(0, 41) ?: create_and_stash(1, 42); +} + +SEC("tc") +long stash_plain(void *ctx) +{ + struct map_value *mapval; + struct plain_local *res; + int idx = 0; + + mapval = bpf_map_lookup_elem(&some_nodes, &idx); + if (!mapval) + return 1; + + res = bpf_obj_new(typeof(*res)); + if (!res) + return 1; + res->key = 41; + + res = bpf_kptr_xchg(&mapval->plain, res); + if (res) + bpf_obj_drop(res); + return 0; +} + +SEC("tc") +long stash_local_with_root(void *ctx) +{ + struct local_with_root *res; + struct map_value *mapval; + struct node_data *n; + int idx = 0; + + mapval = bpf_map_lookup_elem(&some_nodes, &idx); + if (!mapval) + return 1; + + res = bpf_obj_new(typeof(*res)); + if (!res) + return 2; + res->key = 41; + + n = bpf_obj_new(typeof(*n)); + if (!n) { + bpf_obj_drop(res); + return 3; + } + + bpf_spin_lock(&res->l); + bpf_rbtree_add(&res->r, &n->node, less); + bpf_spin_unlock(&res->l); + + res = bpf_kptr_xchg(&mapval->local_root, res); + if (res) { + bpf_obj_drop(res); + return 4; + } + return 0; +} + +SEC("tc") +long unstash_rb_node(void *ctx) +{ + struct map_value *mapval; + struct node_data *res; + long retval; + int key = 1; + + mapval = bpf_map_lookup_elem(&some_nodes, &key); + if (!mapval) + return 1; + + res = bpf_kptr_xchg(&mapval->node, NULL); + if (res) { + retval = res->key; + bpf_obj_drop(res); + return retval; + } + return 1; +} + +SEC("tc") +long stash_test_ref_kfunc(void *ctx) +{ + struct prog_test_ref_kfunc *res; + struct map_value *mapval; + int key = 0; + + mapval = bpf_map_lookup_elem(&some_nodes, &key); + if (!mapval) + return 1; + + res = bpf_kptr_xchg(&mapval->val, NULL); + if (res) + bpf_kfunc_call_test_release(res); + return 0; +} + +SEC("tc") +long refcount_acquire_without_unstash(void *ctx) +{ + struct refcounted_node *p; + struct stash *s; + int ret = 0; + + s = bpf_map_lookup_elem(&refcounted_node_stash, &ret); + if (!s) + return 1; + + if (!s->stashed) + /* refcount_acquire failure is expected when no refcounted_node + * has been stashed before this program executes + */ + return 2; + + p = bpf_refcount_acquire(s->stashed); + if (!p) + return 3; + + ret = s->stashed ? s->stashed->data : -1; + bpf_obj_drop(p); + return ret; +} + +/* Helper for refcount_acquire_without_unstash test */ +SEC("tc") +long stash_refcounted_node(void *ctx) +{ + struct refcounted_node *p; + struct stash *s; + int key = 0; + + s = bpf_map_lookup_elem(&refcounted_node_stash, &key); + if (!s) + return 1; + + p = bpf_obj_new(typeof(*p)); + if (!p) + return 2; + p->data = 42; + + p = bpf_kptr_xchg(&s->stashed, p); + if (p) { + bpf_obj_drop(p); + return 3; + } + + return 0; +} + +char _license[] SEC("license") = "GPL"; |