virtio: ignore corrupted virtqueues rather than spinning.
A corrupt virtqueue (caused by the other end screwing up) can have
strange results such as a driver spinning: just bail when we try to
get a buffer from a known-broken queue.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c2fa5c6..937a49d 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -184,6 +184,11 @@
START_USE(vq);
+ if (unlikely(vq->broken)) {
+ END_USE(vq);
+ return NULL;
+ }
+
if (!more_used(vq)) {
pr_debug("No more buffers in queue\n");
END_USE(vq);