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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 2A8E6C5B578 for ; Wed, 3 Jul 2019 05:20:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F298F21871 for ; Wed, 3 Jul 2019 05:20:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="JLReQKcY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F298F21871 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LSMSVM4V566u4r3XowxnrLl7ywL1zLWhlW9dyDmBklA=; b=JLReQKcYYDKJEM tAiKr5JDDuddY6tzUB32x757U3ZmwyCGSRXQdvTFP5JSyqYfien0vMLht9m/C3levuvOA5yQSzjC4 uq603Jb9UoPyyyQQKF6Cs4uUVcYCns59NR5TZgm9RyivY1mnX/FSlPgZRGuiVAQFOV+/HvLnTEebg Dq+6ukeyfeW1cS1Pn9Hx26t4wdbgc8EE2n0B8U0cnnXXxD11eMzw3B1NGA46gqdDtZXixCkM9L6OO BKfFqzfKwcrydQdaxIItCbfsw+vTRkNBz735TkTFtp1EBpOpPFQPSy5UaYaybKyKBKZyVIfpI0jcN 8M7YpyNj6OXHzzNkTsZA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hiXhC-0004pz-LL; Wed, 03 Jul 2019 05:20:42 +0000 Received: from mga17.intel.com ([192.55.52.151]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hiXh7-0004pS-GG for linux-arm-kernel@lists.infradead.org; Wed, 03 Jul 2019 05:20:38 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Jul 2019 22:20:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,445,1557212400"; d="scan'208";a="164232322" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.122]) ([10.237.72.122]) by fmsmga008.fm.intel.com with ESMTP; 02 Jul 2019 22:20:27 -0700 Subject: Re: [PATCH v1 10/11] perf intel-pt: Smatch: Fix potential NULL pointer dereference To: Leo Yan References: <20190702103420.27540-1-leo.yan@linaro.org> <20190702103420.27540-11-leo.yan@linaro.org> <20190703013553.GB6852@leoy-ThinkPad-X240s> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Wed, 3 Jul 2019 08:19:19 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190703013553.GB6852@leoy-ThinkPad-X240s> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190702_222037_554345_BD90091E X-CRM114-Status: GOOD ( 16.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Song Liu , Peter Zijlstra , Rasmus Villemoes , Jin Yao , Jiri Olsa , Andi Kleen , Eric Saint-Etienne , Konstantin Khlebnikov , Ingo Molnar , Suzuki K Poulose , Arnaldo Carvalho de Melo , Alexios Zavras , Davidlohr Bueso , Namhyung Kim , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Mathieu Poirier , Thomas Richter , linux-kernel@vger.kernel.org, Alexander Shishkin , "David S. Miller" , Changbin Du , Alexey Budankov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 3/07/19 4:35 AM, Leo Yan wrote: > Hi Adrian, > > On Tue, Jul 02, 2019 at 02:07:40PM +0300, Adrian Hunter wrote: >> On 2/07/19 1:34 PM, Leo Yan wrote: >>> Based on the following report from Smatch, fix the potential >>> NULL pointer dereference check. >> >> It never is NULL. Remove the NULL test if you want: >> >> - if (session->itrace_synth_opts && session->itrace_synth_opts->set) { >> + if (session->itrace_synth_opts->set) { >> >> But blindly making changes like below is questionable. > > Thanks for suggestions. > > I checked report and script commands, as you said, both command will > always set session->itrace_synth_opts. For these two commands, we can > safely remove the NULL test. > > Because perf tool contains many sub commands, so I don't have much > confidence it's very safe to remove the NULL test for all cases; e.g. > there have cases which will process aux trace buffer but without > itrace options; for this case, session->itrace_synth_opts might be NULL. > > For either way (remove NULL test or keep NULL test), I don't want to > introduce regression and extra efforts by my patch. So want to double > confirm with you for this :) Yes, intel_pt_process_auxtrace_info() only gets called if a tool sets up the tools->auxtrace_info() callback. The tools that do that also set session->itrace_synth_opts. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel