From: Jiri Olsa <olsajiri@gmail.com>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
martin.lau@kernel.org, kernel-team@meta.com
Subject: Re: [PATCH v2 bpf-next] bpf: consistently use bpf_rcu_lock_held() everywhere
Date: Wed, 15 Oct 2025 11:27:58 +0200 [thread overview]
Message-ID: <aO9pHt32T8BI3Rlt@krava> (raw)
In-Reply-To: <20251014201403.4104511-1-andrii@kernel.org>
On Tue, Oct 14, 2025 at 01:14:03PM -0700, Andrii Nakryiko wrote:
> We have many places which open-code what's now is bpf_rcu_lock_held()
> macro, so replace all those places with a clean and short macro invocation.
> For that, move bpf_rcu_lock_held() macro into include/linux/bpf.h.
>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
jirka
> ---
> v1->v2:
> - move bpf_rcu_lock_held() outside of #ifdef CONFIG_BPF_SYSCALL area (kernel
> test robot).
>
> include/linux/bpf.h | 3 +++
> include/linux/bpf_local_storage.h | 3 ---
> kernel/bpf/hashtab.c | 21 +++++++--------------
> kernel/bpf/helpers.c | 12 ++++--------
> 4 files changed, 14 insertions(+), 25 deletions(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index f87fb203aaae..86afd9ac6848 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -2381,6 +2381,9 @@ bpf_prog_run_array_uprobe(const struct bpf_prog_array *array,
> bool bpf_jit_bypass_spec_v1(void);
> bool bpf_jit_bypass_spec_v4(void);
>
> +#define bpf_rcu_lock_held() \
> + (rcu_read_lock_held() || rcu_read_lock_trace_held() || rcu_read_lock_bh_held())
> +
> #ifdef CONFIG_BPF_SYSCALL
> DECLARE_PER_CPU(int, bpf_prog_active);
> extern struct mutex bpf_stats_enabled_mutex;
> diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h
> index ab7244d8108f..782f58feea35 100644
> --- a/include/linux/bpf_local_storage.h
> +++ b/include/linux/bpf_local_storage.h
> @@ -18,9 +18,6 @@
>
> #define BPF_LOCAL_STORAGE_CACHE_SIZE 16
>
> -#define bpf_rcu_lock_held() \
> - (rcu_read_lock_held() || rcu_read_lock_trace_held() || \
> - rcu_read_lock_bh_held())
> struct bpf_local_storage_map_bucket {
> struct hlist_head list;
> raw_spinlock_t lock;
> diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
> index e7a6ba04dc82..f876f09355f0 100644
> --- a/kernel/bpf/hashtab.c
> +++ b/kernel/bpf/hashtab.c
> @@ -657,8 +657,7 @@ static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
> struct htab_elem *l;
> u32 hash, key_size;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> @@ -1086,8 +1085,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
> /* unknown flags */
> return -EINVAL;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> @@ -1194,8 +1192,7 @@ static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value
> /* unknown flags */
> return -EINVAL;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> @@ -1263,8 +1260,7 @@ static long htab_map_update_elem_in_place(struct bpf_map *map, void *key,
> /* unknown flags */
> return -EINVAL;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> @@ -1326,8 +1322,7 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
> /* unknown flags */
> return -EINVAL;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> @@ -1404,8 +1399,7 @@ static long htab_map_delete_elem(struct bpf_map *map, void *key)
> u32 hash, key_size;
> int ret;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> @@ -1440,8 +1434,7 @@ static long htab_lru_map_delete_elem(struct bpf_map *map, void *key)
> u32 hash, key_size;
> int ret;
>
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
>
> key_size = map->key_size;
>
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index dea8443f782c..825280c953be 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -42,8 +42,7 @@
> */
> BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
> {
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
> return (unsigned long) map->ops->map_lookup_elem(map, key);
> }
>
> @@ -59,8 +58,7 @@ const struct bpf_func_proto bpf_map_lookup_elem_proto = {
> BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
> void *, value, u64, flags)
> {
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
> return map->ops->map_update_elem(map, key, value, flags);
> }
>
> @@ -77,8 +75,7 @@ const struct bpf_func_proto bpf_map_update_elem_proto = {
>
> BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
> {
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
> return map->ops->map_delete_elem(map, key);
> }
>
> @@ -134,8 +131,7 @@ const struct bpf_func_proto bpf_map_peek_elem_proto = {
>
> BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu)
> {
> - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
> - !rcu_read_lock_bh_held());
> + WARN_ON_ONCE(!bpf_rcu_lock_held());
> return (unsigned long) map->ops->map_lookup_percpu_elem(map, key, cpu);
> }
>
> --
> 2.47.3
>
>
next prev parent reply other threads:[~2025-10-15 9:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-14 20:14 [PATCH v2 bpf-next] bpf: consistently use bpf_rcu_lock_held() everywhere Andrii Nakryiko
2025-10-15 9:27 ` Jiri Olsa [this message]
2025-10-15 10:31 ` patchwork-bot+netdevbpf
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