[PATCH 5.4 40/72] perf evlist: Fix cpu/thread map leak

Greg Kroah-Hartman
2020-09-21T16:49:43Z

From: Namhyung Kim <namhyung@kernel.org>

[ Upstream commit bfd1b83d75e44a9f65de30accb3dd3b5940bd3ac ]

Asan reported leak of cpu and thread maps as they have one more refcount
than released. I found that after setting evlist maps it should release
it's refcount.

It seems to be broken from the beginning so I chose the original commit
as the culprit. But not sure how it's applied to stable trees since
there are many changes in the code after that.

Fixes: 7e2ed097538c5 ("perf evlist: Store pointer to the cpu and thread maps")
Fixes: 4112eb1899c0e ("perf evlist: Default to syswide target when no thread/cpu maps set")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/evlist.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index de79c735e4411..505b890ac85cc 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -976,6 +976,10 @@ int perf_evlist__create_maps(struct evlist *evlist, struct target *target)

perf_evlist__set_maps(&evlist->core, cpus, threads);

+ /* as evlist now has references, put count here */
+ perf_cpu_map__put(cpus);
+ perf_thread_map__put(threads);
+
return 0;

out_delete_threads:
@@ -1230,11 +1234,12 @@ static int perf_evlist__create_syswide_maps(struct evlist *evlist)
goto out_put;

perf_evlist__set_maps(&evlist->core, cpus, threads);
-out:
- return err;
+
+ perf_thread_map__put(threads);
out_put:
perf_cpu_map__put(cpus);
- goto out;
+out:
+ return err;
}

int evlist__open(struct evlist *evlist)
--
2.25.1