Commit fcc042a2 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

vhost: copy_from_user -> __copy_from_user 



copy_from_user is pretty high on perf top profile,
replacing it with __copy_from_user helps.
It's also safe because we do access_ok checks during setup.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent d47effe1

drivers/vhost/vhost.c

+1 −1
Original line number Diff line number Diff line
@@ -1171,7 +1171,7 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, 
			       i, vq->num, head);

			return -EINVAL;

		}

		ret = copy_from_user(&desc, vq->desc + i, sizeof desc);

		ret = __copy_from_user(&desc, vq->desc + i, sizeof desc);

		if (unlikely(ret)) {

			vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",

			       i, vq->desc + i);