diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2021-02-10 06:36:33 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-02-11 18:19:26 +0300 |
| commit | 638e4b825d523bed7a55e776c153049fb7716466 (patch) | |
| tree | 38d2be95b066239f129046a77169fe64bb43925d /kernel | |
| parent | dcf33b6f4de173818540e3a2a0668c80a1ebdc68 (diff) | |
| download | linux-638e4b825d523bed7a55e776c153049fb7716466.tar.xz | |
bpf: Allows per-cpu maps and map-in-map in sleepable programs
Since sleepable programs are now executing under migrate_disable
the per-cpu maps are safe to use.
The map-in-map were ok to use in sleepable from the time sleepable
progs were introduced.
Note that non-preallocated maps are still not safe, since there is
no rcu_read_lock yet in sleepable programs and dynamically allocated
map elements are relying on rcu protection. The sleepable programs
have rcu_read_lock_trace instead. That limitation will be addresses
in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-9-alexei.starovoitov@gmail.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/hashtab.c | 4 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 7 |
2 files changed, 8 insertions, 3 deletions
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index c1ac7f964bc9..d63912e73ad9 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1148,7 +1148,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key, /* unknown flags */ return -EINVAL; - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; @@ -1202,7 +1202,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, /* unknown flags */ return -EINVAL; - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); key_size = map->key_size; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 424c1ba0f52f..15c15ea0abf5 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -10384,9 +10384,14 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env, case BPF_MAP_TYPE_HASH: case BPF_MAP_TYPE_LRU_HASH: case BPF_MAP_TYPE_ARRAY: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_ARRAY_OF_MAPS: + case BPF_MAP_TYPE_HASH_OF_MAPS: if (!is_preallocated_map(map)) { verbose(env, - "Sleepable programs can only use preallocated hash maps\n"); + "Sleepable programs can only use preallocated maps\n"); return -EINVAL; } break; |