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| author | Michael S. Tsirkin <mst@redhat.com> | 2021-10-05 10:04:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:22:46 +0300 |
| commit | 32aef620e650ca842f3fbf4cc6415b14714471ba (patch) | |
| tree | 91dbb9062da1e350eb6da0a4bd9e99050c5c93eb /drivers/char | |
| parent | 3d39860bea5e70042da0b090464758af1df82d0f (diff) | |
| download | linux-32aef620e650ca842f3fbf4cc6415b14714471ba.tar.xz | |
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 7eaf303a7a86..3adf04766e98 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1956,6 +1956,13 @@ 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 */ |