Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 22 Apr 2019 11:36:29 +0200
From:   Jiri Olsa <jolsa@redhat.com>
To:     Bo YU <tsu.yubo@gmail.com>
Cc:     peterz@infradead.org, acme@kernel.org,
        alexander.shishkin@linux.intel.com, namhyung@kernel.org,
        ast@kernel.org, daniel@iogearbox.net, kafai@fb.com,
        songliubraving@fb.com, yhs@fb.com, adrian.hunter@intel.com,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        bpf@vger.kernel.org
Subject: Re: [PATCH] perf bpf: return value with unlocking in
 perf_env__find_btf()
Message-ID: <20190422093629.GA1730@krava>
References: <20190422080138.10088-1-tsu.yubo@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190422080138.10088-1-tsu.yubo@gmail.com>
User-Agent: Mutt/1.11.3 (2019-02-01)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@kernel.org>

thanks,
jirka

> Signed-off-by: Bo YU <tsu.yubo@gmail.com>
> ---
>  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
>