Messages in this thread | | | Date | Fri, 24 Oct 2014 17:38:49 +0300 | From | Adrian Hunter <> | Subject | Re: [PATCH 02/16] perf pmu: Let pmu's with no events show up on perf list |
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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) >>
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