Mark data races to pwd->triggered as benign using READ_ONCE and
WRITE_ONCE. These accesses are expected to be racy per comment.
This patch is part of a series of patches aiming at reducing the number
of benign races reported by KCSAN in order to focus future debugging
effort on harmful races.
Reported-by: syzbot+9b3fb64bcc8c1d807595@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 5f820f648c92a ("poll: allow f_op->poll to sleep")
Signed-off-by: Baptiste Lepers <baptiste.lepers@xxxxxxxxx>
---
fs/select.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/select.c b/fs/select.c
index 945896d0ac9e..e71b4d1a2606 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -194,7 +194,7 @@ static int __pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *k
* and is paired with smp_store_mb() in poll_schedule_timeout.
*/
smp_wmb();
- pwq->triggered = 1;
+ WRITE_ONCE(pwq->triggered, 1);
/*
* Perform the default wake up operation using a dummy
@@ -239,7 +239,7 @@ static int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
int rc = -EINTR;
set_current_state(state);
- if (!pwq->triggered)
+ if (!READ_ONCE(pwq->triggered))
rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
__set_current_state(TASK_RUNNING);
--
2.17.1
