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 E9137C63777 for ; Thu, 26 Nov 2020 08:37:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86C1D20B80 for ; Thu, 26 Nov 2020 08:37:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389012AbgKZIhW (ORCPT ); Thu, 26 Nov 2020 03:37:22 -0500 Received: from mga07.intel.com ([134.134.136.100]:51081 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388873AbgKZIhW (ORCPT ); Thu, 26 Nov 2020 03:37:22 -0500 IronPort-SDR: v6QvusKoZUfCmkZjnjhwssnzD9Y+e2sGZbRrKWMxROpMcgPx2b2iwuYpVbp/V4czKo1edJVuN+ Xxkz4MRr71lg== X-IronPort-AV: E=McAfee;i="6000,8403,9816"; a="236386920" X-IronPort-AV: E=Sophos;i="5.78,371,1599548400"; d="scan'208";a="236386920" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Nov 2020 00:37:21 -0800 IronPort-SDR: 1tiM2IaukytXBh6tSek9OBsAlw8mfHkKVuSXHBH5+Ow4zdZeWyQohi/hsmNHVn7Fx5796P+i5e VP1Tyn7Xdsdg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,371,1599548400"; d="scan'208";a="479270689" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.94]) ([10.237.72.94]) by orsmga004.jf.intel.com with ESMTP; 26 Nov 2020 00:37:18 -0800 Subject: Re: [PATCH] perf script: Fix overrun issue for dynamically-allocated pmu type number To: "Jin, Yao" , 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> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <2f48d37f-d7d5-8e61-0894-44b57b61cd88@intel.com> Date: Thu, 26 Nov 2020 10:36:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <8509ed3b-378f-5ee0-5a3e-bbd8cb9d86c4@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.