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| author |   Michael S. Tsirkin <mst@redhat.com> | 2021-10-05 03:04:10 -0400 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-03-04 08:33:22 -0500 |
| commit | 0e7174b9d5877130fec41fb4a16e0c2ee4958d44 (patch) | |
| tree | 7936ce2d33c8b175413c6d257bb77853e4cb1d4f | |
| parent | virtio: document virtio_reset_device (diff) | |
| download | linux-dev-0e7174b9d5877130fec41fb4a16e0c2ee4958d44.tar.xz linux-dev-0e7174b9d5877130fec41fb4a16e0c2ee4958d44.zip | |
virtio_console: break out of buf poll on remove
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>
| -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 2359889a35a0..e3c430539a17 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1957,6 +1957,13 @@ 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 */ virtio_reset_device(vdev); /* Finish up work that's lined up */ |