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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 9DBF9C49EA5 for ; Thu, 24 Jun 2021 19:06:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86B80613D3 for ; Thu, 24 Jun 2021 19:06:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232752AbhFXTI1 (ORCPT ); Thu, 24 Jun 2021 15:08:27 -0400 Received: from mga01.intel.com ([192.55.52.88]:40240 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232694AbhFXTIZ (ORCPT ); Thu, 24 Jun 2021 15:08:25 -0400 IronPort-SDR: uGYjZ+ofxejniPV0NPrmdZBs7EaNtAG8CkT616d/FytDZl6i2hk0jo2etzaHZYzqkRSWj77pUA 3EQZXVbR6WCw== X-IronPort-AV: E=McAfee;i="6200,9189,10025"; a="229131708" X-IronPort-AV: E=Sophos;i="5.83,297,1616482800"; d="scan'208";a="229131708" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2021 12:06:05 -0700 IronPort-SDR: +1qitdYIQ0Xfmc+/A1mpr/8L6W9RRsXrLC6NdDuRbiiVd4LpIO1K9y+mYuvXPjhfMo0ZaZjGLh zLMkHSKmps6w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,297,1616482800"; d="scan'208";a="639887905" Received: from linux.intel.com ([10.54.29.200]) by fmsmga006.fm.intel.com with ESMTP; 24 Jun 2021 12:06:04 -0700 Received: from [10.212.160.234] (kliang2-MOBL.ccr.corp.intel.com [10.212.160.234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id A802058060A; Thu, 24 Jun 2021 12:06:03 -0700 (PDT) Subject: Re: [PATCH] x86: eas should not be NULL when it is referenced From: "Liang, Kan" To: 13145886936@163.com, tglx@linutronix.de, bp@alien8.de, x86@kernel.org Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, gushengxian , "Antonov, Alexander" , Peter Zijlstra References: <20210624070442.34291-1-13145886936@163.com> <40e66cf9-398b-20d7-ce4d-433be6e08921@linux.intel.com> Message-ID: Date: Thu, 24 Jun 2021 15:06:02 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <40e66cf9-398b-20d7-ce4d-433be6e08921@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Oops, forgot to add Peter. On 6/24/2021 3:03 PM, Liang, Kan wrote: > > Hi Shengxian, > > Thanks for the patch. > > On 6/24/2021 3:04 AM, 13145886936@163.com wrote: >> From: gushengxian >> >> "eas" should not be NULL when it is referenced. >> > > I think the NULL pointer dereference of eas should not happen, because > die is -1 if eas is NULL. But the whole error handling path looks fragile. > > We already fixed one issue caused by it in commit ID f797f05d917f > ("perf/x86/intel/uncore: Fix for iio mapping on Skylake Server") > https://lore.kernel.org/lkml/160149233331.7002.10919231011379055356.tip-bot2@tip-bot2/ > > > Maybe something as below? > > From 3de81ba3b04262ef3346297d82f6c4ffb4af7029 Mon Sep 17 00:00:00 2001 > From: Kan Liang > Date: Thu, 24 Jun 2021 11:17:57 -0700 > Subject: [PATCH] perf/x86/intel/uncore: Clean up error handling path of > iio mapping > > The error handling path of iio mapping looks fragile. We already fixed > one issue caused by it, commit ID f797f05d917f ("perf/x86/intel/uncore: > Fix for iio mapping on Skylake Server"). Clean up the error handling > path and make the code robust. > > Reported-by: gushengxian > Signed-off-by: Kan Liang > --- >  arch/x86/events/intel/uncore_snbep.c | 6 ++++-- >  1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/events/intel/uncore_snbep.c > b/arch/x86/events/intel/uncore_snbep.c > index 7622762..6d4a5a9 100644 > --- a/arch/x86/events/intel/uncore_snbep.c > +++ b/arch/x86/events/intel/uncore_snbep.c > @@ -3802,11 +3802,11 @@ pmu_iio_set_mapping(struct intel_uncore_type > *type, struct attribute_group *ag) >      /* One more for NULL. */ >      attrs = kcalloc((uncore_max_dies() + 1), sizeof(*attrs), GFP_KERNEL); >      if (!attrs) > -        goto err; > +        goto clear_topology; > >      eas = kcalloc(uncore_max_dies(), sizeof(*eas), GFP_KERNEL); >      if (!eas) > -        goto err; > +        goto clear_attrs; > >      for (die = 0; die < uncore_max_dies(); die++) { >          sprintf(buf, "die%ld", die); > @@ -3827,7 +3827,9 @@ pmu_iio_set_mapping(struct intel_uncore_type > *type, struct attribute_group *ag) >      for (; die >= 0; die--) >          kfree(eas[die].attr.attr.name); >      kfree(eas); > +clear_attrs: >      kfree(attrs); > +clear_topology: >      kfree(type->topology); >  clear_attr_update: >      type->attr_update = NULL;