virtio: fail adding buffer on broken queues.
Heinz points out that adding buffers to a broken virtqueue (which
should "never happen") still works. Failing allows drivers to detect
and complain about broken devices.
Now drivers are robust, we can add this extra check.
Reported-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 7ae3cba..1e44362 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -204,6 +204,11 @@
BUG_ON(data == NULL);
+ if (unlikely(vq->broken)) {
+ END_USE(vq);
+ return -EIO;
+ }
+
#ifdef DEBUG
{
ktime_t now = ktime_get();
@@ -310,7 +315,7 @@
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM).
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_sgs(struct virtqueue *_vq,
struct scatterlist *sgs[],
@@ -348,7 +353,7 @@
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM).
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_outbuf(struct virtqueue *vq,
struct scatterlist sg[], unsigned int num,
@@ -370,7 +375,7 @@
* Caller must ensure we don't call this with other virtqueue operations
* at the same time (except where noted).
*
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM).
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
*/
int virtqueue_add_inbuf(struct virtqueue *vq,
struct scatterlist sg[], unsigned int num,