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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 6585FC63697 for ; Thu, 26 Nov 2020 14:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3676520B80 for ; Thu, 26 Nov 2020 14:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391160AbgKZOr1 (ORCPT ); Thu, 26 Nov 2020 09:47:27 -0500 Received: from mga06.intel.com ([134.134.136.31]:21356 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390791AbgKZOr0 (ORCPT ); Thu, 26 Nov 2020 09:47:26 -0500 IronPort-SDR: 9OTxOvQy8YX6HC239ylqHr41GsiQQpxl97l9kAUU8G9oIPpnJBce91ZOGwzC+q1Gbi7UiB0MVJ 3Qji7P+Gr/Eg== X-IronPort-AV: E=McAfee;i="6000,8403,9816"; a="233896910" X-IronPort-AV: E=Sophos;i="5.78,372,1599548400"; d="scan'208";a="233896910" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Nov 2020 06:47:25 -0800 IronPort-SDR: XPauXJs9zmHbfOZknqA7ZOCOM9iBy9yfZPOl5Fa4dd5HnY01dJjGtfOgiJICA19WpOb+dAddz5 2sd+e+24iy7A== X-IronPort-AV: E=Sophos;i="5.78,372,1599548400"; d="scan'208";a="547740730" Received: from yjin15-mobl1.ccr.corp.intel.com (HELO [10.254.211.14]) ([10.254.211.14]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Nov 2020 06:47:21 -0800 Subject: Re: [PATCH] perf script: Fix overrun issue for dynamically-allocated pmu type number To: Adrian Hunter , acme@kernel.org, jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com Cc: Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com References: <20201126032425.19226-1-yao.jin@linux.intel.com> <8509ed3b-378f-5ee0-5a3e-bbd8cb9d86c4@linux.intel.com> <2f48d37f-d7d5-8e61-0894-44b57b61cd88@intel.com> From: "Jin, Yao" Message-ID: <9e2e2552-ac94-96e6-9a34-90c9252d419e@linux.intel.com> Date: Thu, 26 Nov 2020 22:47:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <2f48d37f-d7d5-8e61-0894-44b57b61cd88@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 Hi Adrian, On 11/26/2020 4:36 PM, Adrian Hunter wrote: > On 26/11/20 9:06 am, Jin, Yao wrote: >> Hi Adrian, >> >> On 11/26/2020 2:51 PM, Adrian Hunter wrote: >>> On 26/11/20 5:24 am, Jin Yao wrote: >>>> When unpacking the event which is from dynamic pmu, the array >>>> output[OUTPUT_TYPE_MAX] may be overrun. For example, type number of >>>> SKL uncore_imc is 10, but OUTPUT_TYPE_MAX is 7 now (OUTPUT_TYPE_MAX = >>>> PERF_TYPE_MAX + 1). >>>> >>>> /* In builtin-script.c */ >>>> process_event() >>>> { >>>>     unsigned int type = output_type(attr->type); >>>> >>>>     if (output[type].fields == 0) >>>>         return; >>>> } >>>> >>>> output[10] is overrun. >>>> >>>> Create a type OUTPUT_TYPE_OTHER for dynamic pmu events, then >>>> output_type(attr->type) will return OUTPUT_TYPE_OTHER here. >>>> >>>> Note that if PERF_TYPE_MAX ever changed, then there would be a conflict >>>> between old perf.data files that had a dynamicaliy allocated PMU number >>>> that would then be the same as a fixed PERF_TYPE. >>>> >>>> Example: >>>> >>>> perf record --switch-events -C 0 -e >>>> "{cpu-clock,uncore_imc/data_reads/,uncore_imc/data_writes/}:SD" -a -- >>>> sleep 1 >>>> perf script >>>> >>>> Before: >>>>           swapper     0 [000] 1479253.987551:     277766 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.987797:     246709 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.988127:     329883 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.988273:     146393 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.988523:     249977 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.988877:     354090 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.989023:     145940 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.989383:     359856 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1479253.989523:     140082 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>> >>>> After: >>>>           swapper     0 [000] 1397040.402011:     272384 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1397040.402011:       5396 >>>> uncore_imc/data_reads/: >>>>           swapper     0 [000] 1397040.402011:        967 >>>> uncore_imc/data_writes/: >>>>           swapper     0 [000] 1397040.402259:     249153 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1397040.402259:       7231 >>>> uncore_imc/data_reads/: >>>>           swapper     0 [000] 1397040.402259:       1297 >>>> uncore_imc/data_writes/: >>>>           swapper     0 [000] 1397040.402508:     249108 >>>> cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms]) >>>>           swapper     0 [000] 1397040.402508:       5333 >>>> uncore_imc/data_reads/: >>>>           swapper     0 [000] 1397040.402508:       1008 >>>> uncore_imc/data_writes/: >>>> >>>> Fixes: 1405720d4f26 ("perf script: Add 'synth' event type for synthesized >>>> events") >>> >>> It does not look to me like the problem was introduced by that commit.  Are >>> you sure this Fixes tag is correct? >>> >> >> Commit 1405720d4f26 added the change: >> >> @@ -1215,8 +1253,9 @@ static void process_event(struct perf_script *script, >>  { >>         struct thread *thread = al->thread; >>         struct perf_event_attr *attr = &evsel->attr; >> +       unsigned int type = output_type(attr->type); >> >> -       if (output[attr->type].fields == 0) >> +       if (output[type].fields == 0) >>                 return; > > That is a nop if attr->type != PERF_TYPE_SYNTH > Given that PERF_TYPE_SYNTH is (INT_MAX + 1), it is a nop for all kernel > dynamically allocated PMU numbers. > >> >> But of course, we can also say the original "output[attr->type].fields" >> introduced the issue, I'm not sure. Maybe Arnaldo can help to make the >> decision. :) > > I think perf script has always had this problem. > Since perf-script has always had this problem, I'm OK to remove the fixes tag from the patch description. Thanks Jin Yao