Re: [PATCH 05/11] perf parse-event: Fix memory leak in evsel->unit

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Stephane Eranian <eranian@google.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Andi Kleen <ak@linux.intel.com>, Ian Rogers <irogers@google.com>
Subject: Re: [PATCH 05/11] perf parse-event: Fix memory leak in evsel->unit
Date: Tue, 15 Sep 2020 09:19:12 -0300	[thread overview]
Message-ID: <20200915121912.GF720847@kernel.org> (raw)
In-Reply-To: <20200915031819.386559-6-namhyung@kernel.org>

Em Tue, Sep 15, 2020 at 12:18:13PM +0900, Namhyung Kim escreveu:
> The evsel->unit borrows a pointer of pmu event or alias instead of
> owns a string.  But tool event (duration_time) passes a result of
> strdup() caused a leak.
> 
> It was found by ASAN during metric test:

Thanks, applied.

>   Direct leak of 210 byte(s) in 70 object(s) allocated from:
>     #0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
>     #1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414
>     #2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414
>     #3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
>     #4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
>     #5 0x559fbbcc95da in __parse_events util/parse-events.c:2141
>     #6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406
>     #7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393
>     #8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415
>     #9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498
>     #10 0x559fbbc0109b in run_test tests/builtin-test.c:410
>     #11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
>     #12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
>     #13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
>     #14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
>     #15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
>     #16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
>     #17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
>     #18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308
> 
> Acked-by: Jiri Olsa <jolsa@redhat.com>
> Fixes: f0fbb114e3025 ("perf stat: Implement duration_time as a proper event")
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  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 b35e4bb1cecb..ece321ccf599 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -416,7 +416,7 @@ static int add_event_tool(struct list_head *list, int *idx,
>  		return -ENOMEM;
>  	evsel->tool_event = tool_event;
>  	if (tool_event == PERF_TOOL_DURATION_TIME)
> -		evsel->unit = strdup("ns");
> +		evsel->unit = "ns";
>  	return 0;
>  }
>  
> -- 
> 2.28.0.618.gf4bc123cb7-goog
> 

-- 

- Arnaldo