projects/linux·commit 2b73d207

Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2b73d207 · Linus Torvalds <[email protected]> · 2014-02-20 12:00:27 -08:00

Pull workqueue fixes from Tejun Heo:
 "Two workqueue fixes.  One for an unlikely but possible critical bug
  during kworker shutdown and the other to make lockdep names a bit more
  descriptive"

* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: ensure @task is valid across kthread_stop()
  workqueue: add args to workqueue lockdep name
Commit
2b73d207a5437bb930f72cf87e09ad12ad492e90
Parents
d4964961 · 5bdfff96

Merge commit. Changes below are compared with the first parent: d4964961.

Changes

2 files changed · +8 −4

FileStatusAddDelContent
include/linux/workqueue.hmodified+1−4View file
kernel/workqueue.cmodified+7−0View file

include/linux/workqueue.h

View file
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 594521b..704f4f6 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -419,10 +419,7 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
static struct lock_class_key __key; \
const char *__lock_name; \
\
- if (__builtin_constant_p(fmt)) \
- __lock_name = (fmt); \
- else \
- __lock_name = #fmt; \
+ __lock_name = #fmt#args; \
\
__alloc_workqueue_key((fmt), (flags), (max_active), \
&__key, __lock_name, ##args); \

kernel/workqueue.c

View file
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 82ef9f3..193e977 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1851,6 +1851,12 @@ static void destroy_worker(struct worker *worker)
if (worker->flags & WORKER_IDLE)
pool->nr_idle--;
+ /*
+ * Once WORKER_DIE is set, the kworker may destroy itself at any
+ * point. Pin to ensure the task stays until we're done with it.
+ */
+ get_task_struct(worker->task);
+
list_del_init(&worker->entry);
worker->flags |= WORKER_DIE;
@@ -1859,6 +1865,7 @@ static void destroy_worker(struct worker *worker)
spin_unlock_irq(&pool->lock);
kthread_stop(worker->task);
+ put_task_struct(worker->task);
kfree(worker);
spin_lock_irq(&pool->lock);