From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 205A2C433F5 for ; Thu, 10 Mar 2022 17:17:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244439AbiCJRSP (ORCPT ); Thu, 10 Mar 2022 12:18:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239175AbiCJRSN (ORCPT ); Thu, 10 Mar 2022 12:18:13 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60D80187BA5 for ; Thu, 10 Mar 2022 09:17:12 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C4BF2B82705 for ; Thu, 10 Mar 2022 17:17:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBA2EC340E8; Thu, 10 Mar 2022 17:17:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646932629; bh=2czeYZEhYrw+eEsPeWClwqc/1LpOrFNLlEfPbHjGD/8=; h=Subject:From:To:Cc:Date:From; b=Fn9iwM4mptqfym/gS03mQe6/YlHfI28Xu6K9Uqc6I47tseIM6F8mztbUfLBRv7kUc SDeea/byD+MHrmOCKTBK81kUBdxUVYbcxQ4NDTkEYAjNG/LaAfZtiHa0zFSuHOnUY+ cSJGXLdEcXAEsXhqJDM5sBtl4qFM7zElXuRZaZhSnqI6vaZCzU0gfITkxMzxXdaYsv yVL+C5/NkoCq1Xv8ujUwsT7suJcRD9k6q8uoaU2ckddpf6BxP1vWDQrPrMdaeuiKSN FtUUhd5OX9aXFn9XPFLvyGhihn2zx7gvixCabXM/9Hs5l2KtTMTHrtgTZjSeJNkK2X yaHSWnD1LqecA== Message-ID: <77deca8cbfd226981b3f1eab203967381e9b5bd9.camel@kernel.org> Subject: [PATCH] tracing: Fix strncpy warning in trace_events_synth.c From: Tom Zanussi To: Steven Rostedt Cc: kernel test robot , kbuild-all@lists.01.org, Linux Memory Management List , linux-kernel@vger.kernel.org Date: Thu, 10 Mar 2022 11:17:07 -0600 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 0-day reported the strncpy error below: ../kernel/trace/trace_events_synth.c: In function 'last_cmd_set': ../kernel/trace/trace_events_synth.c:65:9: warning: 'strncpy' specified bound depends on the length o\ f the source argument [-Wstringop-truncation] 65 | strncpy(last_cmd, str, strlen(str) + 1); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../kernel/trace/trace_events_synth.c:65:32: note: length computed here 65 | strncpy(last_cmd, str, strlen(str) + 1); | ^~~~~~~~~~~ There's no reason to use strncpy here, in fact there's no reason to do anything but a simple kstrdup() (note we don't even need to check for failure since last_cmod is expected to be either the last cmd string or NULL, and the containing function is a void return). Fixes: 27c888da9867 ("tracing: Remove size restriction on synthetic event cmd error logging") Reported-by: kernel test robot Signed-off-by: Tom Zanussi --- kernel/trace/trace_events_synth.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index fdd79e07e2fc..5e8c07aef071 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -58,11 +58,8 @@ static void last_cmd_set(const char *str) return; kfree(last_cmd); - last_cmd = kzalloc(strlen(str) + 1, GFP_KERNEL); - if (!last_cmd) - return; - strncpy(last_cmd, str, strlen(str) + 1); + last_cmd = kstrdup(str, GFP_KERNEL); } static void synth_err(u8 err_type, u16 err_pos) -- 2.17.1