diff options
| author | Hou Tao <houtao1@huawei.com> | 2025-01-08 09:07:14 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-01-08 18:06:35 -0800 |
| commit | ea5b229630a631ee6a72e1f58bc40029efc1daf8 (patch) | |
| tree | 7f24c8d8efb01327833d955baed549e2d84fd2a7 /kernel/bpf | |
| parent | 1b1a01db17af7a44cae8d8d7d7a18dbb056be40f (diff) | |
bpf: Remove migrate_{disable|enable} in ->map_for_each_callback
BPF program may call bpf_for_each_map_elem(), and it will call
the ->map_for_each_callback callback of related bpf map. Considering the
running context of bpf program has already disabled migration, remove
the unnecessary migrate_{disable|enable} pair in the implementations of
->map_for_each_callback. To ensure the guarantee will not be voilated
later, also add cant_migrate() check in the implementations.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250108010728.207536-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/arraymap.c | 6 | ||||
| -rw-r--r-- | kernel/bpf/hashtab.c | 11 |
2 files changed, 7 insertions, 10 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 6cdbb4c33d31..eb28c0f219ee 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -735,13 +735,13 @@ static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback u64 ret = 0; void *val; + cant_migrate(); + if (flags != 0) return -EINVAL; is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; array = container_of(map, struct bpf_array, map); - if (is_percpu) - migrate_disable(); for (i = 0; i < map->max_entries; i++) { if (is_percpu) val = this_cpu_ptr(array->pptrs[i]); @@ -756,8 +756,6 @@ static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback break; } - if (is_percpu) - migrate_enable(); return num_elems; } diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 3ec941a0ea41..42af7fac61b9 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -2208,17 +2208,18 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_ bool is_percpu; u64 ret = 0; + cant_migrate(); + if (flags != 0) return -EINVAL; is_percpu = htab_is_percpu(htab); roundup_key_size = round_up(map->key_size, 8); - /* disable migration so percpu value prepared here will be the - * same as the one seen by the bpf program with bpf_map_lookup_elem(). + /* migration has been disabled, so percpu value prepared here will be + * the same as the one seen by the bpf program with + * bpf_map_lookup_elem(). */ - if (is_percpu) - migrate_disable(); for (i = 0; i < htab->n_buckets; i++) { b = &htab->buckets[i]; rcu_read_lock(); @@ -2244,8 +2245,6 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_ rcu_read_unlock(); } out: - if (is_percpu) - migrate_enable(); return num_elems; } |