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-rw-r--r--include/linux/bpf-cgroup.h54
-rw-r--r--include/linux/bpf.h54
-rw-r--r--include/linux/sched.h3
-rw-r--r--kernel/bpf/helpers.c16
-rw-r--r--kernel/bpf/local_storage.c3
-rw-r--r--kernel/fork.c1
-rw-r--r--net/bpf/test_run.c23
7 files changed, 54 insertions, 100 deletions
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 8b77d08d4b47..a74cd1c3bd87 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -27,19 +27,6 @@ struct task_struct;
extern struct static_key_false cgroup_bpf_enabled_key[MAX_BPF_ATTACH_TYPE];
#define cgroup_bpf_enabled(type) static_branch_unlikely(&cgroup_bpf_enabled_key[type])
-#define BPF_CGROUP_STORAGE_NEST_MAX 8
-
-struct bpf_cgroup_storage_info {
- struct task_struct *task;
- struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE];
-};
-
-/* For each cpu, permit maximum BPF_CGROUP_STORAGE_NEST_MAX number of tasks
- * to use bpf cgroup storage simultaneously.
- */
-DECLARE_PER_CPU(struct bpf_cgroup_storage_info,
- bpf_cgroup_storage_info[BPF_CGROUP_STORAGE_NEST_MAX]);
-
#define for_each_cgroup_storage_type(stype) \
for (stype = 0; stype < MAX_BPF_CGROUP_STORAGE_TYPE; stype++)
@@ -172,44 +159,6 @@ static inline enum bpf_cgroup_storage_type cgroup_storage_type(
return BPF_CGROUP_STORAGE_SHARED;
}
-static inline int bpf_cgroup_storage_set(struct bpf_cgroup_storage
- *storage[MAX_BPF_CGROUP_STORAGE_TYPE])
-{
- enum bpf_cgroup_storage_type stype;
- int i, err = 0;
-
- preempt_disable();
- for (i = 0; i < BPF_CGROUP_STORAGE_NEST_MAX; i++) {
- if (unlikely(this_cpu_read(bpf_cgroup_storage_info[i].task) != NULL))
- continue;
-
- this_cpu_write(bpf_cgroup_storage_info[i].task, current);
- for_each_cgroup_storage_type(stype)
- this_cpu_write(bpf_cgroup_storage_info[i].storage[stype],
- storage[stype]);
- goto out;
- }
- err = -EBUSY;
- WARN_ON_ONCE(1);
-
-out:
- preempt_enable();
- return err;
-}
-
-static inline void bpf_cgroup_storage_unset(void)
-{
- int i;
-
- for (i = 0; i < BPF_CGROUP_STORAGE_NEST_MAX; i++) {
- if (unlikely(this_cpu_read(bpf_cgroup_storage_info[i].task) != current))
- continue;
-
- this_cpu_write(bpf_cgroup_storage_info[i].task, NULL);
- return;
- }
-}
-
struct bpf_cgroup_storage *
cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
void *key, bool locked);
@@ -487,9 +436,6 @@ static inline int cgroup_bpf_prog_query(const union bpf_attr *attr,
return -EINVAL;
}
-static inline int bpf_cgroup_storage_set(
- struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE]) { return 0; }
-static inline void bpf_cgroup_storage_unset(void) {}
static inline int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux,
struct bpf_map *map) { return 0; }
static inline struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 0edff8f5177e..978ebd16ae60 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1142,38 +1142,40 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array,
struct bpf_prog *include_prog,
struct bpf_prog_array **new_array);
+struct bpf_run_ctx {};
+
+struct bpf_cg_run_ctx {
+ struct bpf_run_ctx run_ctx;
+ struct bpf_prog_array_item *prog_item;
+};
+
/* BPF program asks to bypass CAP_NET_BIND_SERVICE in bind. */
#define BPF_RET_BIND_NO_CAP_NET_BIND_SERVICE (1 << 0)
/* BPF program asks to set CN on the packet. */
#define BPF_RET_SET_CN (1 << 0)
-/* For BPF_PROG_RUN_ARRAY_FLAGS and __BPF_PROG_RUN_ARRAY,
- * if bpf_cgroup_storage_set() failed, the rest of programs
- * will not execute. This should be a really rare scenario
- * as it requires BPF_CGROUP_STORAGE_NEST_MAX number of
- * preemptions all between bpf_cgroup_storage_set() and
- * bpf_cgroup_storage_unset() on the same cpu.
- */
#define BPF_PROG_RUN_ARRAY_FLAGS(array, ctx, func, ret_flags) \
({ \
struct bpf_prog_array_item *_item; \
struct bpf_prog *_prog; \
struct bpf_prog_array *_array; \
+ struct bpf_run_ctx *old_run_ctx; \
+ struct bpf_cg_run_ctx run_ctx; \
u32 _ret = 1; \
u32 func_ret; \
migrate_disable(); \
rcu_read_lock(); \
_array = rcu_dereference(array); \
_item = &_array->items[0]; \
+ old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); \
while ((_prog = READ_ONCE(_item->prog))) { \
- if (unlikely(bpf_cgroup_storage_set(_item->cgroup_storage))) \
- break; \
+ run_ctx.prog_item = _item; \
func_ret = func(_prog, ctx); \
_ret &= (func_ret & 1); \
- *(ret_flags) |= (func_ret >> 1); \
- bpf_cgroup_storage_unset(); \
+ *(ret_flags) |= (func_ret >> 1); \
_item++; \
} \
+ bpf_reset_run_ctx(old_run_ctx); \
rcu_read_unlock(); \
migrate_enable(); \
_ret; \
@@ -1184,6 +1186,8 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array,
struct bpf_prog_array_item *_item; \
struct bpf_prog *_prog; \
struct bpf_prog_array *_array; \
+ struct bpf_run_ctx *old_run_ctx; \
+ struct bpf_cg_run_ctx run_ctx; \
u32 _ret = 1; \
migrate_disable(); \
rcu_read_lock(); \
@@ -1191,17 +1195,13 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array,
if (unlikely(check_non_null && !_array))\
goto _out; \
_item = &_array->items[0]; \
- while ((_prog = READ_ONCE(_item->prog))) { \
- if (!set_cg_storage) { \
- _ret &= func(_prog, ctx); \
- } else { \
- if (unlikely(bpf_cgroup_storage_set(_item->cgroup_storage))) \
- break; \
- _ret &= func(_prog, ctx); \
- bpf_cgroup_storage_unset(); \
- } \
+ old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);\
+ while ((_prog = READ_ONCE(_item->prog))) { \
+ run_ctx.prog_item = _item; \
+ _ret &= func(_prog, ctx); \
_item++; \
} \
+ bpf_reset_run_ctx(old_run_ctx); \
_out: \
rcu_read_unlock(); \
migrate_enable(); \
@@ -1284,6 +1284,20 @@ static inline void bpf_enable_instrumentation(void)
migrate_enable();
}
+static inline struct bpf_run_ctx *bpf_set_run_ctx(struct bpf_run_ctx *new_ctx)
+{
+ struct bpf_run_ctx *old_ctx;
+
+ old_ctx = current->bpf_ctx;
+ current->bpf_ctx = new_ctx;
+ return old_ctx;
+}
+
+static inline void bpf_reset_run_ctx(struct bpf_run_ctx *old_ctx)
+{
+ current->bpf_ctx = old_ctx;
+}
+
extern const struct file_operations bpf_map_fops;
extern const struct file_operations bpf_prog_fops;
extern const struct file_operations bpf_iter_fops;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ec8d07d88641..c64119aa2e60 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -42,6 +42,7 @@ struct backing_dev_info;
struct bio_list;
struct blk_plug;
struct bpf_local_storage;
+struct bpf_run_ctx;
struct capture_control;
struct cfs_rq;
struct fs_struct;
@@ -1379,6 +1380,8 @@ struct task_struct {
#ifdef CONFIG_BPF_SYSCALL
/* Used by BPF task local storage */
struct bpf_local_storage __rcu *bpf_storage;
+ /* Used for BPF run context */
+ struct bpf_run_ctx *bpf_ctx;
#endif
#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 9fe846ec6bd1..15746f779fe1 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -393,8 +393,6 @@ 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 +401,13 @@ 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 = 0; i < BPF_CGROUP_STORAGE_NEST_MAX; i++) {
- if (unlikely(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];
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 95d70a08325d..362e81481594 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -11,9 +11,6 @@
#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 \
diff --git a/kernel/fork.c b/kernel/fork.c
index bc94b2cc5995..e8b41e212110 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2083,6 +2083,7 @@ 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/net/bpf/test_run.c b/net/bpf/test_run.c
index cda8375bbbaf..8d46e2962786 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -88,17 +88,19 @@ reset:
static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
u32 *retval, u32 *time, bool xdp)
{
- struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { NULL };
+ struct bpf_prog_array_item item = {.prog = prog};
+ struct bpf_run_ctx *old_ctx;
+ struct bpf_cg_run_ctx run_ctx;
struct bpf_test_timer t = { NO_MIGRATE };
enum bpf_cgroup_storage_type stype;
int ret;
for_each_cgroup_storage_type(stype) {
- storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
- if (IS_ERR(storage[stype])) {
- storage[stype] = NULL;
+ item.cgroup_storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
+ if (IS_ERR(item.cgroup_storage[stype])) {
+ item.cgroup_storage[stype] = NULL;
for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_free(storage[stype]);
+ bpf_cgroup_storage_free(item.cgroup_storage[stype]);
return -ENOMEM;
}
}
@@ -107,22 +109,19 @@ static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
repeat = 1;
bpf_test_timer_enter(&t);
+ old_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
do {
- ret = bpf_cgroup_storage_set(storage);
- if (ret)
- break;
-
+ run_ctx.prog_item = &item;
if (xdp)
*retval = bpf_prog_run_xdp(prog, ctx);
else
*retval = BPF_PROG_RUN(prog, ctx);
-
- bpf_cgroup_storage_unset();
} while (bpf_test_timer_continue(&t, repeat, &ret, time));
+ bpf_reset_run_ctx(old_ctx);
bpf_test_timer_leave(&t);
for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_free(storage[stype]);
+ bpf_cgroup_storage_free(item.cgroup_storage[stype]);
return ret;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.