From 70670444c20a10717acdc1f4c1e420852995496d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 13 Mar 2014 11:23:40 +1030 Subject: 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 Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/virtio/virtio_ring.c') diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 7ae3cba2f624..1e443629f76d 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -204,6 +204,11 @@ static inline int virtqueue_add(struct virtqueue *_vq, BUG_ON(data == NULL); + if (unlikely(vq->broken)) { + END_USE(vq); + return -EIO; + } + #ifdef DEBUG { ktime_t now = ktime_get(); @@ -310,7 +315,7 @@ add_head: * 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 @@ EXPORT_SYMBOL_GPL(virtqueue_add_sgs); * 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 @@ EXPORT_SYMBOL_GPL(virtqueue_add_outbuf); * 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, -- cgit v1.2.3