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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D706EC0650E for ; Wed, 3 Jul 2019 18:46:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B14CB2189E for ; Wed, 3 Jul 2019 18:46:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LcrCBtv0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727113AbfGCSqx (ORCPT ); Wed, 3 Jul 2019 14:46:53 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:36513 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726430AbfGCSqw (ORCPT ); Wed, 3 Jul 2019 14:46:52 -0400 Received: by mail-qk1-f193.google.com with SMTP id g18so3663496qkl.3 for ; Wed, 03 Jul 2019 11:46:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=lxu8VUMKdHDWmo8g651uclV2QTSciyGC6y+pb/rVSnA=; b=LcrCBtv0ZLyYgyWByF03aD3dLFbITDwQ1iSk30xGE3IhRzWt5t1cWtvKTGuSak9Ac1 quTV3uebdg2gbweRYhm/FLETgusswD3ACUx5Jp7wyeDzi/4MgZJI5nQNtHzYXmGViOLA 1aD4NTa7kMGsGryyYAfTMCyd7CcCDAXDjiZJhPjjR1xSm/5lAVeSJFEjJZapJfQfTVAn rkKPnVnzu8UZgRolZzWrcKM3QWca9yP4REnXyY9uqXM6p5fSTHmoK3sI0rQRRZUjcsRD EtYmCcEKrC6pWoGvdbTsC5Zgu4IcSDW2fq4MbgFGwlID1ZWslqA795FQevvT0yvubwLu wBpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=lxu8VUMKdHDWmo8g651uclV2QTSciyGC6y+pb/rVSnA=; b=IgnQfNsHpLxaS4b9+WzuIkT+ApZ9Aqk4flLQ1/bYsK/88zjmeQtKtMupibHAJZ+LiX J3sDjrNSAlVV2h43QRHbRuRl6C4eF2i2Nbnhilj86SCPeenrK4PiTd2AQk7PDtZSLCWB FOddjB6vadMCaqHW0U68tVwEg6i65Sv1zFBjbCboSRLnxuGBkG0V8OC4tMT9fGs3IRSy SVzXEfwsom1cyNi3WkJKVhQvFuix/JXSDvGTX3Co+NS0x2AdMGC7u2SZZ2S9Uk3Bb1IY 0zTztuqBYvUOsHtp43HyLnun4G+ydoRXUu5FUNBgg657AZ1XHNvu9LMc02fClfic2qZF iAYg== X-Gm-Message-State: APjAAAUSnKmFn9mgn9JTJu8eIuFH6JxJrgDhQdz/8iG0kMT9uViljjWf 2QbWcdkd34MAGN7R/JWuI5s= X-Google-Smtp-Source: APXvYqzDpt++1yhZV/LZqaA/Mo161b2L7HhcxUJ5L6Nvz8+pmH1ZynDUyuCrcHkK0BTItHD+miOUTw== X-Received: by 2002:a37:4dc6:: with SMTP id a189mr31364013qkb.41.1562179611820; Wed, 03 Jul 2019 11:46:51 -0700 (PDT) Received: from quaco.ghostprotocols.net ([177.195.209.182]) by smtp.gmail.com with ESMTPSA id u7sm1402263qta.82.2019.07.03.11.46.30 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 03 Jul 2019 11:46:51 -0700 (PDT) From: Arnaldo Carvalho de Melo X-Google-Original-From: Arnaldo Carvalho de Melo Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id CAA0141154; Wed, 3 Jul 2019 15:46:06 -0300 (-03) Date: Wed, 3 Jul 2019 15:46:06 -0300 To: Leo Yan Cc: Peter Zijlstra , Ingo Molnar , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Mathieu Poirier , Suzuki K Poulose , Andi Kleen , "David S. Miller" , Davidlohr Bueso , Rasmus Villemoes , Jin Yao , Song Liu , Adrian Hunter , Alexios Zavras , Thomas Gleixner , Changbin Du , Eric Saint-Etienne , Konstantin Khlebnikov , Thomas Richter , Alexey Budankov , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v1 05/11] perf trace: Smatch: Fix potential NULL pointer dereference Message-ID: <20190703184606.GF10740@kernel.org> References: <20190702103420.27540-1-leo.yan@linaro.org> <20190702103420.27540-6-leo.yan@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190702103420.27540-6-leo.yan@linaro.org> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Jul 02, 2019 at 06:34:14PM +0800, Leo Yan escreveu: > Based on the following report from Smatch, fix the potential > NULL pointer dereference check. > > tools/perf/builtin-trace.c:1044 > thread_trace__new() error: we previously assumed 'ttrace' could be > null (see line 1041). > > tools/perf/builtin-trace.c > 1037 static struct thread_trace *thread_trace__new(void) > 1038 { > 1039 struct thread_trace *ttrace = zalloc(sizeof(struct thread_trace)); > 1040 > 1041 if (ttrace) > 1042 ttrace->files.max = -1; > 1043 > 1044 ttrace->syscall_stats = intlist__new(NULL); > ^^^^^^^^ > 1045 > 1046 return ttrace; > 1047 } > > This patch directly returns NULL when fail to allocate memory for > ttrace; this can avoid potential NULL pointer dereference. I did it slightly different, to avoid having two return lines, and that is what most other constructors (foo__new()) do in tools/perf/, kept your changeset comment and patch authorship, thanks. diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index d0eb7224dd36..e3fc9062f136 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1038,10 +1038,10 @@ static struct thread_trace *thread_trace__new(void) { struct thread_trace *ttrace = zalloc(sizeof(struct thread_trace)); - if (ttrace) + if (ttrace) { ttrace->files.max = -1; - - ttrace->syscall_stats = intlist__new(NULL); + ttrace->syscall_stats = intlist__new(NULL); + } return ttrace; }