Re: [PATCH v2 2/2] perf parse-event: Fix cpu map leaks

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Sep 17, 2020 at 03:02:19PM +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.
> 
> This fixes the following ASAN report:

This one should come first, and the patch summary is:

  "perf parse-events Fix cpu map refcounting"

Then the next patch fixes the refcoutnt leak on the error path.

I'm fixing this up,

Thanks,

- Arnaldo
 
>   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@redhat.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/parse-events.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 176a51698a64..fbe0d3143353 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)
> @@ -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