Messages in this thread | | | Date | Fri, 24 Oct 2014 11:45:00 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 02/16] perf pmu: Let pmu's with no events show up on perf list |
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Em Fri, Oct 24, 2014 at 05:36:46PM +0300, Adrian Hunter escreveu: > 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.
Oops, yeah, my bad, it should not have the !, fixing...
> > 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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