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; }