From: "Michael S. Tsirkin" <[email protected]> virtio ring was changed to return an error code on OOM, but one caller was missed and still checks for vq->vring.num. The fix is just to check for <0 error code.
Long term it might make sense to change goto add_head to just return an error on oom instead, but let's apply a minimal fix for 2.6.35. Reported-by: Chris Mason <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Rusty Russell <[email protected]> Tested-by: Chris Mason <[email protected]> --- diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index dd35b34..bffec32 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -164,7 +164,8 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq, gfp_t gfp) { struct vring_virtqueue *vq = to_vvq(_vq); - unsigned int i, avail, head, uninitialized_var(prev); + unsigned int i, avail, uninitialized_var(prev); + int head; START_USE(vq); @@ -174,8 +175,8 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq, * buffers, then go indirect. FIXME: tune this threshold */ if (vq->indirect && (out + in) > 1 && vq->num_free) { head = vring_add_indirect(vq, sg, out, in, gfp); - if (head != vq->vring.num) + if (likely(head >= 0)) goto add_head; } BUG_ON(out + in > vq->vring.num); _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
