From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756225AbaJXOiz (ORCPT ); Fri, 24 Oct 2014 10:38:55 -0400 Received: from mga03.intel.com ([134.134.136.65]:57706 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127AbaJXOiy (ORCPT ); Fri, 24 Oct 2014 10:38:54 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,780,1406617200"; d="scan'208";a="595292759" Message-ID: <544A6479.8030601@intel.com> Date: Fri, 24 Oct 2014 17:38:49 +0300 From: Adrian Hunter User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo , Namhyung Kim CC: Peter Zijlstra , linux-kernel@vger.kernel.org, David Ahern , Frederic Weisbecker , Jiri Olsa , Paul Mackerras , Stephane Eranian Subject: Re: [PATCH 02/16] perf pmu: Let pmu's with no events show up on perf list References: <1414061124-26830-1-git-send-email-adrian.hunter@intel.com> <1414061124-26830-3-git-send-email-adrian.hunter@intel.com> <87y4s6cak7.fsf@sejong.aot.lge.com> <20141024125702.GZ14687@kernel.org> <20141024130320.GA14687@kernel.org> <20141024132141.GB14687@kernel.org> <544A63FE.60902@intel.com> In-Reply-To: <544A63FE.60902@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/10/2014 5:36 p.m., Adrian Hunter wrote: > On 24/10/2014 4:21 p.m., Arnaldo Carvalho de Melo wrote: >> Em Fri, Oct 24, 2014 at 10:03:20AM -0300, Arnaldo Carvalho de Melo escreveu: >>> Em Fri, Oct 24, 2014 at 09:57:02AM -0300, Arnaldo Carvalho de Melo escreveu: >>>> Em Fri, Oct 24, 2014 at 02:15:52PM +0900, Namhyung Kim escreveu: >>>>> On Thu, 23 Oct 2014 13:45:10 +0300, Adrian Hunter wrote: >>>>>> + if (pmu->selectable) { >>>>>> + scnprintf(buf, sizeof(buf), "%s//", pmu->name); >>>>>> + aliases[j] = strdup(buf); >>>>> >>>>> You need to check the return value here (and above too). >>>> >>>> Well spotted, fixing this up. >>> >>> Oh well, this print_pmu_events() function needs some care, it starts by >>> trying to alloc the array, if it fails, it silently returns, does that >>> mean that there are no pmu events? Or that memory allocation failed? >>> >>> Ok, will do the fixes in a separate patch... >>> >>> - Arnaldo >> >> The patch below should check everything and warn the user, even >> maintaining that void return... >> >> Acked-by tags welcome as always :-) >> >> - Arnaldo >> >> >> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c >> index 91dca60..881b754 100644 >> --- a/tools/perf/util/pmu.c >> +++ b/tools/perf/util/pmu.c >> @@ -753,9 +753,9 @@ void print_pmu_events(const char *event_glob, bool name_only) >> if (pmu->selectable) >> len++; >> } >> - aliases = malloc(sizeof(char *) * len); >> + aliases = zalloc(sizeof(char *) * len); >> if (!aliases) >> - return; >> + goto out_enomem; > > That path tries to free aliases[j] but aliases is null. You could set len to 0 in that case. Than again, no it doesn't sorry for the noise. > >> pmu = NULL; >> j = 0; >> while ((pmu = perf_pmu__scan(pmu)) != NULL) { >> @@ -768,16 +768,20 @@ void print_pmu_events(const char *event_glob, bool name_only) >> (!is_cpu && strglobmatch(alias->name, >> event_glob)))) >> continue; >> - aliases[j] = name; >> + >> if (is_cpu && !name_only) >> - aliases[j] = format_alias_or(buf, sizeof(buf), >> - pmu, alias); >> - aliases[j] = strdup(aliases[j]); >> + name = format_alias_or(buf, sizeof(buf), pmu, alias); >> + >> + aliases[j] = strdup(name); >> + if (aliases[j] == NULL) >> + goto out_enomem; >> j++; >> } >> if (pmu->selectable) { >> - scnprintf(buf, sizeof(buf), "%s//", pmu->name); >> - aliases[j] = strdup(buf); >> + char *s; >> + if (asprintf(&s, "%s//", pmu->name) < 0) >> + goto out_enomem; >> + aliases[j] = s; >> j++; >> } >> } >> @@ -789,12 +793,20 @@ void print_pmu_events(const char *event_glob, bool name_only) >> continue; >> } >> printf(" %-50s [Kernel PMU event]\n", aliases[j]); >> - zfree(&aliases[j]); >> printed++; >> } >> if (printed) >> printf("\n"); >> - free(aliases); >> +out_free: >> + for (j = 0; j < len; j++) >> + zfree(&aliases[j]); >> + zfree(&aliases); >> + return; >> + >> +out_enomem: >> + printf("FATAL: not enough memory to print PMU events\n"); >> + if (aliases) >> + goto out_free; >> } >> >> bool pmu_have_event(const char *pname, const char *name) >>