Re: [PATCH] perf bpf: return value with unlocking in perf_env__find_btf()

From: Jiri Olsa
Date: Mon Apr 22 2019 - 05:36:35 EST


On Mon, Apr 22, 2019 at 04:01:38AM -0400, Bo YU wrote:
> In perf_env__find_btf(), returning without unlocking
> "env->bpf_progs.lock". There may be cause lockdep issue.
>
> DEtected by CoversityScan, CID# 1444762:(program hangs(LOCK))
>
> Fixes: 2db7b1e0bd49d: (perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf())

ugh, sry about that

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka

> Signed-off-by: Bo YU <tsu.yubo@xxxxxxxxx>
> ---
> tools/perf/util/env.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index 9494f9dc61ec..6a3eaf7d9353 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -115,8 +115,8 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
> }
> node = NULL;
>
> - up_read(&env->bpf_progs.lock);
> out:
> + up_read(&env->bpf_progs.lock);
> return node;
> }
>
> --
> 2.11.0
>