Re: [PATCH 2/2] perf parse-event: Fix cpu map leaks

From: Arnaldo Carvalho de Melo
Date: Wed Sep 16 2020 - 15:12:30 EST


Em Wed, Sep 16, 2020 at 02:31:31PM +0900, Namhyung Kim escreveu:
> Like evlist cpu map, evsel's cpu map should have a proper refcount.
> As it's created with a refcount, we don't need to get an extra count.
> Thanks to Arnaldo for the simpler suggestion.

You forgot this part:


[acme@five perf]$ git diff
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 667cbca1547ac5f6..0154331ea213f166 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -353,7 +353,7 @@ __add_event(struct list_head *list, int *idx,
const char *cpu_list)
{
struct evsel *evsel;
- struct perf_cpu_map *cpus = pmu ? pmu->cpus :
+ struct perf_cpu_map *cpus = pmu ? perf_cpu_map__get(pmu->cpus) :
cpu_list ? perf_cpu_map__new(cpu_list) : NULL;

if (init_attr)

Right?

- Arnaldo

> This fixes the following ASAN report:
>
> Direct leak of 840 byte(s) in 70 object(s) allocated from:
> #0 0x7fe36703f628 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x107628)
> #1 0x559fbbf611ca in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
> #2 0x559fbbf6229c in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:237
> #3 0x559fbbcc6c6d in __add_event util/parse-events.c:357
> #4 0x559fbbcc6c6d in add_event_tool util/parse-events.c:408
> #5 0x559fbbcc6c6d in parse_events_add_tool util/parse-events.c:1414
> #6 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
> #7 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
> #8 0x559fbbcc95da in __parse_events util/parse-events.c:2141
> #9 0x559fbbc2788b in check_parse_id tests/pmu-events.c:406
> #10 0x559fbbc2788b in check_parse_id tests/pmu-events.c:393
> #11 0x559fbbc2788b in check_parse_fake tests/pmu-events.c:436
> #12 0x559fbbc2788b in metric_parse_fake tests/pmu-events.c:553
> #13 0x559fbbc27e2d in test_parsing_fake tests/pmu-events.c:599
> #14 0x559fbbc27e2d in test_parsing_fake tests/pmu-events.c:574
> #15 0x559fbbc0109b in run_test tests/builtin-test.c:410
> #16 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
> #17 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
> #18 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
> #19 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
> #20 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
> #21 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
> #22 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
> #23 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308
>
> And I've failed which commit introduced this bug as the code was
> heavily changed since then. ;-/
>
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/util/parse-events.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 176a51698a64..204395596381 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -366,7 +366,7 @@ __add_event(struct list_head *list, int *idx,
> }
>
> (*idx)++;
> - evsel->core.cpus = perf_cpu_map__get(cpus);
> + evsel->core.cpus = cpus;
> evsel->core.own_cpus = perf_cpu_map__get(cpus);
> evsel->core.system_wide = pmu ? pmu->is_uncore : false;
> evsel->auto_merge_stats = auto_merge_stats;
> --
> 2.28.0.618.gf4bc123cb7-goog
>

--

- Arnaldo