From: Zhen Lei <thunder.leizhen@xxxxxxxxxx> [ Upstream commit c6f87141254d16e281e4b4431af7316895207b8f ] 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. Fixes: 6c502584438bda63 ("perf unwind: Call unwind__prepare_access for forked thread") Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: zhen lei <thunder.leizhen@xxxxxxxxxx> Link: http://lore.kernel.org/lkml/20210415092744.3793-1-thunder.leizhen@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 e2537d5acab0..f4d44f75ba15 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -836,15 +836,18 @@ out: 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) -- 2.30.2