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

From: Jiri Olsa <[email-masked]>
Date: Mon, 22 Apr 2019 11:36:29 +0200

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 <[email-masked]>

thanks,
jirka

> Signed-off-by: Bo YU <[email-masked]>
> ---
>  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
>