Commit-ID: 6584140ba9e6762dd7ec73795243289b914f31f9
Gitweb: https://git.kernel.org/tip/6584140ba9e6762dd7ec73795243289b914f31f9
Author: Namhyung Kim <namhyung@xxxxxxxxxx>
AuthorDate: Wed, 22 May 2019 14:32:48 +0900
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 28 May 2019 09:52:23 -0300
perf namespace: Protect reading thread's namespace
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>
---
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 403045a2bbea..b413ba5b9835 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -133,7 +133,7 @@ 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;
@@ -141,10 +141,21 @@ 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)
|