media: cec-core: first mark device unregistered, then wake up fhs

If a CEC device node is unregistered, then it should be marked as
unregistered before waking up any filehandles that are waiting for
an event.

This ensures that there is no race condition where an application can
call CEC_DQEVENT and have the ioctl return 0 instead of ENODEV.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Hans Verkuil 2020-10-09 11:16:16 +02:00 committed by Mauro Carvalho Chehab
parent 01c7a8167d
commit e91c255733

View file

@ -166,12 +166,12 @@ static void cec_devnode_unregister(struct cec_adapter *adap)
mutex_unlock(&devnode->lock);
return;
}
devnode->registered = false;
devnode->unregistered = true;
list_for_each_entry(fh, &devnode->fhs, list)
wake_up_interruptible(&fh->wait);
devnode->registered = false;
devnode->unregistered = true;
mutex_unlock(&devnode->lock);
mutex_lock(&adap->lock);