Re: [PATCH 08/11] perf metric: Free metric when it failed to resolve

Arnaldo Carvalho de Melo
2020-09-15T12:27:11Z

Em Tue, Sep 15, 2020 at 12:18:16PM +0900, Namhyung Kim escreveu:
> The metricgroup__add_metric() can find multiple match for a metric
> group and it's possible to fail. Also it can fail in the middle like
> in resolve_metric() even for single metric.

Thanks, applied.

- Arnaldo

>
> In those cases, the intermediate list and ids will be leaked like:
>
> Direct leak of 3 byte(s) in 1 object(s) allocated from:
> #0 0x7f4c938f40b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
> #1 0x55f7e71c1bef in __add_metric util/metricgroup.c:683
> #2 0x55f7e71c31d0 in add_metric util/metricgroup.c:906
> #3 0x55f7e71c3844 in metricgroup__add_metric util/metricgroup.c:940
> #4 0x55f7e71c488d in metricgroup__add_metric_list util/metricgroup.c:993
> #5 0x55f7e71c488d in parse_groups util/metricgroup.c:1045
> #6 0x55f7e71c60a4 in metricgroup__parse_groups_test util/metricgroup.c:1087
> #7 0x55f7e71235ae in __compute_metric tests/parse-metric.c:164
> #8 0x55f7e7124650 in compute_metric tests/parse-metric.c:196
> #9 0x55f7e7124650 in test_recursion_fail tests/parse-metric.c:318
> #10 0x55f7e7124650 in test__parse_metric tests/parse-metric.c:356
> #11 0x55f7e70be09b in run_test tests/builtin-test.c:410
> #12 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
> #13 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
> #14 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
> #15 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
> #16 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
> #17 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
> #18 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
> #19 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308
>
> Acked-by: Jiri Olsa <jolsa@redhat.com>
> Fixes: 83de0b7d535de ("perf metric: Collect referenced metrics in struct metric_ref_node")
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/perf/util/metricgroup.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index 53747df601fa..35bcaa8d11e9 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -940,7 +940,7 @@ static int metricgroup__add_metric(const char *metric, bool metric_no_group,
>
> ret = add_metric(&list, pe, metric_no_group, &m, NULL, &ids);
> if (ret)
> - return ret;
> + goto out;
>
> /*
> * Process any possible referenced metrics
> @@ -949,12 +949,14 @@ static int metricgroup__add_metric(const char *metric, bool metric_no_group,
> ret = resolve_metric(metric_no_group,
> &list, map, &ids);
> if (ret)
> - return ret;
> + goto out;
> }
>
> /* End of pmu events. */
> - if (!has_match)
> - return -EINVAL;
> + if (!has_match) {
> + ret = -EINVAL;
> + goto out;
> + }
>
> list_for_each_entry(m, &list, nd) {
> if (events->len > 0)
> @@ -969,9 +971,14 @@ static int metricgroup__add_metric(const char *metric, bool metric_no_group,
> }
> }
>
> +out:
> + /*
> + * add to metric_list so that they can be released
> + * even if it's failed
> + */
> list_splice(&list, metric_list);
> expr_ids__exit(&ids);
> - return 0;
> + return ret;
> }
>
> static int metricgroup__add_metric_list(const char *list, bool metric_no_group,
> --
> 2.28.0.618.gf4bc123cb7-goog
>

--

- Arnaldo