diff options
| author | Linux Build Service Account <lnxbuild@localhost> | 2016-10-26 13:13:25 -0700 |
|---|---|---|
| committer | Gerrit - the friendly Code Review server <code-review@localhost> | 2016-10-26 13:13:24 -0700 |
| commit | bcd8ec9210c9048c14d934e16267ba79a894db09 (patch) | |
| tree | 7e3f49424f21431eab08f679ea6213d6dfa32d1c /kernel/bpf/syscall.c | |
| parent | b12304a53614f77f37dd87b470ae76084e768966 (diff) | |
| parent | 617229a3e9400c58b578077ff6f81d2f25a1f5ff (diff) | |
Merge "Merge remote-tracking branch 'msm-4.4/tmp-510d0a3f' into msm-4.4"
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; |