Commit b5570ca7 authored by Zhaolong Zhang's avatar Zhaolong Zhang Committed by Greg Kroah-Hartman
Browse files

uio: dismiss waiters on device unregistration 



When the device is unregistered, it should wake up the blocking waiters.
Otherwise, they will sleep forever.

Signed-off-by: default avatarZhaolong Zhang <zhangzl2013@126.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3b1ad360

drivers/uio/uio.c

+11 −8
Original line number Diff line number Diff line
@@ -569,20 +569,20 @@ static ssize_t uio_read(struct file *filep, char __user *buf, 
	ssize_t retval = 0;

	s32 event_count;



	mutex_lock(&idev->info_lock);

	if (!idev->info || !idev->info->irq)

		retval = -EIO;

	mutex_unlock(&idev->info_lock);



	if (retval)

		return retval;



	if (count != sizeof(s32))

		return -EINVAL;



	add_wait_queue(&idev->wait, &wait);



	do {

		mutex_lock(&idev->info_lock);

		if (!idev->info || !idev->info->irq) {

			retval = -EIO;

			mutex_unlock(&idev->info_lock);

			break;

		}

		mutex_unlock(&idev->info_lock);



		set_current_state(TASK_INTERRUPTIBLE);



		event_count = atomic_read(&idev->event);
@@ -1017,6 +1017,9 @@ void uio_unregister_device(struct uio_info *info) 
	idev->info = NULL;

	mutex_unlock(&idev->info_lock);



	wake_up_interruptible(&idev->wait);

	kill_fasync(&idev->async_queue, SIGIO, POLL_HUP);



	device_unregister(&idev->dev);



	return;