Commit 28a1dbb6 authored by Jan Kiszka's avatar Jan Kiszka Committed by David S. Miller
Browse files

CAPI: Fix racy capi_read 



capi_read still used interruptible_sleep_on, risking to miss a wakeup
this way. Convert it to wait_event_interruptible.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@web.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 54f0fad3

drivers/isdn/capi/capi.c

+7 −12
Original line number Diff line number Diff line
@@ -657,24 +657,19 @@ capi_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) 
	struct capidev *cdev = (struct capidev *)file->private_data;

	struct sk_buff *skb;

	size_t copied;

	int err;



	if (!cdev->ap.applid)

		return -ENODEV;



	if ((skb = skb_dequeue(&cdev->recvqueue)) == NULL) {



	skb = skb_dequeue(&cdev->recvqueue);

	if (!skb) {

		if (file->f_flags & O_NONBLOCK)

			return -EAGAIN;



		for (;;) {

			interruptible_sleep_on(&cdev->recvwait);

			if ((skb = skb_dequeue(&cdev->recvqueue)) != NULL)

				break;

			if (signal_pending(current))

				break;

		}

		if (skb == NULL)

			return -ERESTARTNOHAND;

		err = wait_event_interruptible(cdev->recvwait,

				(skb = skb_dequeue(&cdev->recvqueue)));

		if (err)

			return err;

	}

	if (skb->len > count) {

		skb_queue_head(&cdev->recvqueue, skb);