From 54ad64129cc166b9eec7151f3f9fc83589e33555 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 30 May 2008 10:03:32 +0200 Subject: [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 --- drivers/s390/char/raw3270.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'drivers/s390/char/raw3270.c') 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; -- cgit v1.2.3