On 2021/4/15 20:42, Arnaldo Carvalho de Melo wrote:
> Em Thu, Apr 15, 2021 at 05:27:44PM +0800, Zhen Lei escreveu:
>> Although 'err' has been initialized to -ENOMEM, but it will be reassigned
>> by the "err = unwind__prepare_access(...)" statement in the for loop. So
>> that, the value of 'err' is unknown when map__clone() failed.
>
> You forgot to research and add this:
>
> Fixes: 6c502584438bda63 ("perf unwind: Call unwind__prepare_access for forked
> thread")
>
> So that the sta...@kernel.org guys can pick this up automagically and
> apply this fix to the stable kernels.
>
> I've added it.
OK, thank you very much.
>
> Thanks, applied.
>
> - Arnaldo
>
>> Reported-by: Hulk Robot <hul...@huawei.com>
>> Signed-off-by: Zhen Lei <thunder.leiz...@huawei.com>
>> ---
>> tools/perf/util/map.c | 7 +++++--
>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>> index fbc40a2c17d4dca..8af693d9678cefe 100644
>> --- a/tools/perf/util/map.c
>> +++ b/tools/perf/util/map.c
>> @@ -840,15 +840,18 @@ int maps__fixup_overlappings(struct maps *maps, struct
>> map *map, FILE *fp)
>> int maps__clone(struct thread *thread, struct maps *parent)
>> {
>> struct maps *maps = thread->maps;
>> - int err = -ENOMEM;
>> + int err;
>> struct map *map;
>>
>> down_read(&parent->lock);
>>
>> maps__for_each_entry(parent, map) {
>> struct map *new = map__clone(map);
>> - if (new == NULL)
>> +
>> + if (new == NULL) {
>> + err = -ENOMEM;
>> goto out_unlock;
>> + }
>>
>> err = unwind__prepare_access(maps, new, NULL);
>> if (err)
>> --
>> 2.26.0.106.g9fadedd
>>
>>
>
