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

From: Greg Kroah-Hartman
Date: Mon Sep 21 2020 - 12:49:43 EST

From: Namhyung Kim <namhyung@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20200915031819.386559-4-namhyung@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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;

@@ -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);
- return err;
+ perf_thread_map__put(threads);
- goto out;
+ return err;

int evlist__open(struct evlist *evlist)