Messages in this thread | | | Date | Fri, 24 Oct 2014 17:36:46 +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 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.
> 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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