When the device is unregistered, it should wake up the blocking waiters. Otherwise, they will sleep forever.
Signed-off-by: Zhaolong Zhang <[email protected]> --- drivers/uio/uio.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 8564466..08fa55d 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -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); @@ -1014,6 +1014,9 @@ 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; -- 1.9.1
