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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-05-30 10:03:32 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-05-30 10:03:35 +0200 |
| commit | 54ad64129cc166b9eec7151f3f9fc83589e33555 (patch) | |
| tree | 62653aafec6b61da39a58c4cac2c1b5e37860df1 /drivers/s390/char/raw3270.c | |
| parent | [S390] dasd: use a generic wait_queue for sleep_on (diff) | |
| download | linux-dev-54ad64129cc166b9eec7151f3f9fc83589e33555.tar.xz linux-dev-54ad64129cc166b9eec7151f3f9fc83589e33555.zip | |
[S390] 3270: fix race with stack local wait_queue_head_t.
A wait_event call with a stack local wait_queue_head_t structure that is
used to do the wake up for the wait_event is inherently racy. After the
wait_event finished the wake_up call might not have completed yet.
Remove the stack local wait_queue_head_t from raw3270_start_init and
use the global raw3270_wait_queue instead.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to '')
| -rw-r--r-- | drivers/s390/char/raw3270.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/s390/char/raw3270.c b/drivers/s390/char/raw3270.c index 0d98f1ff2edd..848ef7e8523f 100644 --- a/drivers/s390/char/raw3270.c +++ b/drivers/s390/char/raw3270.c @@ -549,7 +549,6 @@ raw3270_start_init(struct raw3270 *rp, struct raw3270_view *view, struct raw3270_request *rq) { unsigned long flags; - wait_queue_head_t wq; int rc; #ifdef CONFIG_TN3270_CONSOLE @@ -566,20 +565,20 @@ raw3270_start_init(struct raw3270 *rp, struct raw3270_view *view, return rq->rc; } #endif - init_waitqueue_head(&wq); rq->callback = raw3270_wake_init; - rq->callback_data = &wq; + rq->callback_data = &raw3270_wait_queue; spin_lock_irqsave(get_ccwdev_lock(view->dev->cdev), flags); rc = __raw3270_start(rp, view, rq); spin_unlock_irqrestore(get_ccwdev_lock(view->dev->cdev), flags); if (rc) return rc; /* Now wait for the completion. */ - rc = wait_event_interruptible(wq, raw3270_request_final(rq)); + rc = wait_event_interruptible(raw3270_wait_queue, + raw3270_request_final(rq)); if (rc == -ERESTARTSYS) { /* Interrupted by a signal. */ raw3270_halt_io(view->dev, rq); /* No wait for the halt to complete. */ - wait_event(wq, raw3270_request_final(rq)); + wait_event(raw3270_wait_queue, raw3270_request_final(rq)); return -ERESTARTSYS; } return rq->rc; |