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: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jan Kiszka 2010-02-08 10:12:21 +00:00 committed by David S. Miller
parent 54f0fad3d8
commit 28a1dbb6f7

View file

@ -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);