diff options
| -rw-r--r-- | kernel/bpf/helpers.c | 104 |
1 files changed, 102 insertions, 2 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index fe827f6e5234..1fc002cfe2b1 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1109,11 +1109,18 @@ struct bpf_hrtimer { struct hrtimer timer; }; -/* the actual struct hidden inside uapi struct bpf_timer */ +struct bpf_work { + struct bpf_async_cb cb; + struct work_struct work; + struct work_struct delete_work; +}; + +/* the actual struct hidden inside uapi struct bpf_timer and bpf_wq */ struct bpf_async_kern { union { struct bpf_async_cb *cb; struct bpf_hrtimer *timer; + struct bpf_work *work; }; /* bpf_spin_lock is used here instead of spinlock_t to make * sure that it always fits into space reserved by struct bpf_timer @@ -1124,6 +1131,7 @@ struct bpf_async_kern { enum bpf_async_type { BPF_ASYNC_TYPE_TIMER = 0, + BPF_ASYNC_TYPE_WQ, }; static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running); @@ -1167,11 +1175,64 @@ out: return HRTIMER_NORESTART; } +static void bpf_wq_work(struct work_struct *work) +{ + struct bpf_work *w = container_of(work, struct bpf_work, work); + struct bpf_tramp_run_ctx __maybe_unused run_ctx; + struct bpf_async_cb *cb = &w->cb; + struct bpf_prog *prog = cb->prog; + struct bpf_map *map = cb->map; + bpf_callback_t callback_fn; + void *value = cb->value; + void *key; + u32 idx; + + BTF_TYPE_EMIT(struct bpf_wq); + + callback_fn = READ_ONCE(cb->callback_fn); + if (!callback_fn || !prog) + return; + + 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); + } + + run_ctx.bpf_cookie = 0; + + if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { + /* recursion detected */ + __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); + return; + } + + callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0); + /* The verifier checked that return value is zero. */ + + __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, + &run_ctx); +} + +static void bpf_wq_delete_work(struct work_struct *work) +{ + struct bpf_work *w = container_of(work, struct bpf_work, delete_work); + + cancel_work_sync(&w->work); + + kfree_rcu(w, cb.rcu); +} + static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u64 flags, enum bpf_async_type type) { struct bpf_async_cb *cb; struct bpf_hrtimer *t; + struct bpf_work *w; clockid_t clockid; size_t size; int ret = 0; @@ -1183,6 +1244,9 @@ static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u case BPF_ASYNC_TYPE_TIMER: size = sizeof(struct bpf_hrtimer); break; + case BPF_ASYNC_TYPE_WQ: + size = sizeof(struct bpf_work); + break; default: return -EINVAL; } @@ -1201,13 +1265,22 @@ static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u goto out; } - if (type == BPF_ASYNC_TYPE_TIMER) { + switch (type) { + case BPF_ASYNC_TYPE_TIMER: clockid = flags & (MAX_CLOCKS - 1); t = (struct bpf_hrtimer *)cb; hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT); t->timer.function = bpf_timer_cb; cb->value = (void *)async - map->record->timer_off; + break; + case BPF_ASYNC_TYPE_WQ: + w = (struct bpf_work *)cb; + + INIT_WORK(&w->work, bpf_wq_work); + INIT_WORK(&w->delete_work, bpf_wq_delete_work); + cb->value = (void *)async - map->record->wq_off; + break; } cb->map = map; cb->prog = NULL; @@ -1473,7 +1546,19 @@ void bpf_timer_cancel_and_free(void *val) */ void bpf_wq_cancel_and_free(void *val) { + struct bpf_work *work; + BTF_TYPE_EMIT(struct bpf_wq); + + work = (struct bpf_work *)__bpf_async_cancel_and_free(val); + if (!work) + return; + /* Trigger cancel of the sleepable work, but *do not* wait for + * it to finish if it was running as we might not be in a + * sleepable context. + * kfree will be called once the work has finished. + */ + schedule_work(&work->delete_work); } BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr) @@ -2612,6 +2697,20 @@ __bpf_kfunc void bpf_throw(u64 cookie) WARN(1, "A call to BPF exception callback should never return\n"); } +__bpf_kfunc int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) +{ + struct bpf_async_kern *async = (struct bpf_async_kern *)wq; + struct bpf_map *map = p__map; + + BUILD_BUG_ON(sizeof(struct bpf_async_kern) > sizeof(struct bpf_wq)); + BUILD_BUG_ON(__alignof__(struct bpf_async_kern) != __alignof__(struct bpf_wq)); + + if (flags) + return -EINVAL; + + return __bpf_async_init(async, map, flags, BPF_ASYNC_TYPE_WQ); +} + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(generic_btf_ids) @@ -2689,6 +2788,7 @@ BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly) BTF_ID_FLAGS(func, bpf_dynptr_size) BTF_ID_FLAGS(func, bpf_dynptr_clone) BTF_ID_FLAGS(func, bpf_modify_return_test_tp) +BTF_ID_FLAGS(func, bpf_wq_init) BTF_KFUNCS_END(common_btf_ids) static const struct btf_kfunc_id_set common_kfunc_set = { |