This reverts commit f9dac92ba9081062a6477ee015bd3b8c5914efc4.
leads to crashes with no ACCESS_PLATFORM when
sysctl net.core.high_order_alloc_disable=1
Reported-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
Message-ID: <8b20cc28-45a9-4643-8e87-ba164a540c0a@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index be7309b1e860..06b5bdf0920e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2782,7 +2782,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize);
*
* Returns zero or a negative error.
* 0: success.
- * -EINVAL: too late to enable premapped mode, the vq already contains buffers.
+ * -EINVAL: vring does not use the dma api, so we can not enable premapped mode.
*/
int virtqueue_set_dma_premapped(struct virtqueue *_vq)
{
@@ -2798,6 +2798,11 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
return -EINVAL;
}
+ if (!vq->use_dma_api) {
+ END_USE(vq);
+ return -EINVAL;
+ }
+
vq->premapped = true;
vq->do_unmap = false;
--
MST
