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authorNamhyung Kim <namhyung@kernel.org>2019-05-22 07:32:48 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-05-28 14:52:23 +0200
commit6584140ba9e6762dd7ec73795243289b914f31f9 (patch)
tree6fe8c8903c16a4a1f296530c7bd7523f824013e4 /tools
parenttools headers UAPI: Sync drm/drm.h with the kernel (diff)
downloadlinux-6584140ba9e6762dd7ec73795243289b914f31f9.tar.xz
linux-6584140ba9e6762dd7ec73795243289b914f31f9.zip
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@kernel.org> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Krister Johansen <kjlx@templeofstupid.com> Link: http://lkml.kernel.org/r/20190522053250.207156-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/thread.c15
1 files 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)