diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2021-10-05 03:04:10 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 14:39:47 +0200 |
| commit | c97ffb4184f0521dfaba8be14dd76795d69e604a (patch) | |
| tree | 62ab22a7519803b6eae34f11c7cad910974c3b59 /drivers/char | |
| parent | 0c00d38337ec2cc26ff0e40ac7f2cb0d1318da7f (diff) | |
virtio_console: break out of buf poll on remove
[ Upstream commit 0e7174b9d5877130fec41fb4a16e0c2ee4958d44 ]
A common pattern for device reset is currently:
vdev->config->reset(vdev);
.. cleanup ..
reset prevents new interrupts from arriving and waits for interrupt
handlers to finish.
However if - as is common - the handler queues a work request which is
flushed during the cleanup stage, we have code adding buffers / trying
to get buffers while device is reset. Not good.
This was reproduced by running
modprobe virtio_console
modprobe -r virtio_console
in a loop.
Fix this up by calling virtio_break_device + flush before reset.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1786239
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/virtio_console.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 673522874cec..3dd4deb60adb 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1959,6 +1959,13 @@ static void virtcons_remove(struct virtio_device *vdev) list_del(&portdev->list); spin_unlock_irq(&pdrvdata_lock); + /* Device is going away, exit any polling for buffers */ + virtio_break_device(vdev); + if (use_multiport(portdev)) + flush_work(&portdev->control_work); + else + flush_work(&portdev->config_work); + /* Disable interrupts for vqs */ vdev->config->reset(vdev); /* Finish up work that's lined up */ |