Re: [PATCH v1] perf record: fix memory leak on AIO objects deallocation

From: Alexey Budankov
Date: Thu Dec 06 2018 - 13:10:15 EST


On 06.12.2018 20:05, Arnaldo Carvalho de Melo wrote:
> Em Wed, Dec 05, 2018 at 08:19:41PM +0300, Alexey Budankov escreveu:
>>
>> Sending a part which was missed between v12 and v13 of the patch set
>> introducing AIO trace streaming for perf record mode.
>>
>> The part is essential to avoid memory leakage during deallocation
>> of AIO related trace data buffers.
>>
>> It is applied on top of acme perf/core repo.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
>> ---
>> tools/perf/util/mmap.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
>> index ab30555d2afc..169d02973757 100644
>> --- a/tools/perf/util/mmap.c
>> +++ b/tools/perf/util/mmap.c
>> @@ -207,8 +207,18 @@ static int perf_mmap__aio_mmap(struct perf_mmap *map, struct mmap_params *mp)
>>
>> static void perf_mmap__aio_munmap(struct perf_mmap *map)
>> {
>> + int i;
>> +
>> + for (i = 0; i < map->aio.nr_cblocks; ++i) {
>> + if (map->aio.data[i])
>> + zfree(&map->aio.data[i]);
>> + }
>> if (map->aio.data)
>> zfree(&map->aio.data);
>> + if (map->aio.cblocks)
>> + zfree(&map->aio.cblocks);
>> + if (map->aio.aiocb)
>> + zfree(&map->aio.aiocb);
>
> There is no need to check for NULL before calling zfree(), as it is just
> a wrapper for free that sets that variable to NULL after calling it.
>
> And free(NULL) is valid, just a noop to avoid having all those tests
> before each call to free(). I'm making those plain zfree() and later
> will do a sweep at removing other cases.

Thank you.
-Alexey

>
>> }
>>
>> int perf_mmap__aio_push(struct perf_mmap *md, void *to, int idx,
>