Re: [PATCH] rtla/osnoise: fix NULL but dereferenced coccicheck errors

From: Daniel Bristot de Oliveira <bristot@kernel.org>
To: Wan Jiabing <wanjiabing@vivo.com>
Cc: kael_w@qq.com, Steven Rostedt <rostedt@goodmis.org>,
	linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rtla/osnoise: fix NULL but dereferenced coccicheck errors
Date: Thu, 31 Mar 2022 14:25:45 +0200	[thread overview]
Message-ID: <2afd6cba-1a01-0c32-eae8-c4f9f7e76732@kernel.org> (raw)
In-Reply-To: <20220322113253.57390-1-wanjiabing@vivo.com>

Hi Wan

On 3/22/22 12:32, Wan Jiabing wrote:
> Fix the following coccicheck errors:
> ./tools/tracing/rtla/src/osnoise_hist.c:870:31-36: ERROR: record is NULL but dereferenced.
> ./tools/tracing/rtla/src/osnoise_top.c:650:31-36: ERROR: record is NULL but dereferenced.
> 
> "record" is NULL before calling osnoise_init_trace_tool.
> Add a tag "out_free" to avoid dereferring a NULL pointer.

Yes, I see the problem.

Please, change the Subject to something with better information about the
problem, instead of the way you fund it.

> Fixes: 51d64c3a1819 ("rtla: Add -e/--event support")
> Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
> ---
>  tools/tracing/rtla/src/osnoise_hist.c | 5 +++--
>  tools/tracing/rtla/src/osnoise_top.c  | 9 +++++----
>  2 files changed, 8 insertions(+), 6 deletions(-)

Please, also add the version of coccicheck you are using, because it seems that
there is a problem with it. There is a similar problem with timerlat, added by
the same patch, but it seems that coccicheck did not find it.

Would you mind to check coccicheck, and also add the fix for timerlat?

Thanks.
-- Daniel