diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-03-10 16:23:19 +0000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2020-03-12 14:26:50 -0400 |
| commit | 00d5d15b0641f4ae463253eba06c836d56c2ce42 (patch) | |
| tree | e3e206c15d3ab9fad053303d930fe8190ac5aca9 | |
| parent | 2333e829952fb437db915bbb17f4d8c43127d438 (diff) | |
workqueue: Mark up unlocked access to wq->first_flusher
[ 7329.671518] BUG: KCSAN: data-race in flush_workqueue / flush_workqueue
[ 7329.671549]
[ 7329.671572] write to 0xffff8881f65fb250 of 8 bytes by task 37173 on cpu 2:
[ 7329.671607] flush_workqueue+0x3bc/0x9b0 (kernel/workqueue.c:2844)
[ 7329.672527]
[ 7329.672540] read to 0xffff8881f65fb250 of 8 bytes by task 37175 on cpu 0:
[ 7329.672571] flush_workqueue+0x28d/0x9b0 (kernel/workqueue.c:2835)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | kernel/workqueue.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5afa9ad45eba..40a4ba39ad5e 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2832,7 +2832,7 @@ void flush_workqueue(struct workqueue_struct *wq) * First flushers are responsible for cascading flushes and * handling overflow. Non-first flushers can simply return. */ - if (wq->first_flusher != &this_flusher) + if (READ_ONCE(wq->first_flusher) != &this_flusher) return; mutex_lock(&wq->mutex); @@ -2841,7 +2841,7 @@ void flush_workqueue(struct workqueue_struct *wq) if (wq->first_flusher != &this_flusher) goto out_unlock; - wq->first_flusher = NULL; + WRITE_ONCE(wq->first_flusher, NULL); WARN_ON_ONCE(!list_empty(&this_flusher.list)); WARN_ON_ONCE(wq->flush_color != this_flusher.flush_color); |