From: Namhyung Kim <namhyung@xxxxxxxxxx> [ Upstream commit 6584140ba9e6762dd7ec73795243289b914f31f9 ] It seems that the current code lacks holding the namespace lock in thread__namespaces(). Otherwise it can see inconsistent results. Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Hari Bathini <hbathini@xxxxxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Krister Johansen <kjlx@xxxxxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20190522053250.207156-2-namhyung@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/perf/util/thread.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 50678d318185..b800752745af 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -132,7 +132,7 @@ void thread__put(struct thread *thread) } } -struct namespaces *thread__namespaces(const struct thread *thread) +static struct namespaces *__thread__namespaces(const struct thread *thread) { if (list_empty(&thread->namespaces_list)) return NULL; @@ -140,10 +140,21 @@ struct namespaces *thread__namespaces(const struct thread *thread) return list_first_entry(&thread->namespaces_list, struct namespaces, list); } +struct namespaces *thread__namespaces(const struct thread *thread) +{ + struct namespaces *ns; + + down_read((struct rw_semaphore *)&thread->namespaces_lock); + ns = __thread__namespaces(thread); + up_read((struct rw_semaphore *)&thread->namespaces_lock); + + return ns; +} + static int __thread__set_namespaces(struct thread *thread, u64 timestamp, struct namespaces_event *event) { - struct namespaces *new, *curr = thread__namespaces(thread); + struct namespaces *new, *curr = __thread__namespaces(thread); new = namespaces__new(event); if (!new) -- 2.20.1
