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| author | Alex Shi <alex.shi@linaro.org> | 2016-05-20 12:16:37 +0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2016-05-20 12:16:37 +0800 |
| commit | 510d0a3f869611dcd001a2b7627fa5dded4579af (patch) | |
| tree | ba06ce27af2f3aa194a268e3f26f0665c21357a9 /kernel/bpf/syscall.c | |
| parent | e37ddf27108a992e191b27df9bd532cb9157dc89 (diff) | |
| parent | 544ec5b08d007f184ab97abdbed87e613c8c0b83 (diff) | |
Merge tag 'v4.4.11' into linux-linaro-lsk-v4.4
This is the 4.4.11 stable release
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 3b39550d8485..4e32cc94edd9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -181,11 +181,18 @@ struct bpf_map *__bpf_map_get(struct fd f) return f.file->private_data; } -void bpf_map_inc(struct bpf_map *map, bool uref) +/* prog's and map's refcnt limit */ +#define BPF_MAX_REFCNT 32768 + +struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref) { - atomic_inc(&map->refcnt); + if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) { + atomic_dec(&map->refcnt); + return ERR_PTR(-EBUSY); + } if (uref) atomic_inc(&map->usercnt); + return map; } struct bpf_map *bpf_map_get_with_uref(u32 ufd) @@ -197,7 +204,7 @@ struct bpf_map *bpf_map_get_with_uref(u32 ufd) if (IS_ERR(map)) return map; - bpf_map_inc(map, true); + map = bpf_map_inc(map, true); fdput(f); return map; @@ -580,6 +587,15 @@ static struct bpf_prog *__bpf_prog_get(struct fd f) return f.file->private_data; } +struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) +{ + if (atomic_inc_return(&prog->aux->refcnt) > BPF_MAX_REFCNT) { + atomic_dec(&prog->aux->refcnt); + return ERR_PTR(-EBUSY); + } + return prog; +} + /* called by sockets/tracing/seccomp before attaching program to an event * pairs with bpf_prog_put() */ @@ -592,7 +608,7 @@ struct bpf_prog *bpf_prog_get(u32 ufd) if (IS_ERR(prog)) return prog; - atomic_inc(&prog->aux->refcnt); + prog = bpf_prog_inc(prog); fdput(f); return prog; |