virtio: Fix used_idx wrap-around

The more_used() function compares the vq->vring.used->idx with last_used_idx.
Since vq->vring.used->idx is a 16-bit integer, and last_used_idx is an
unsigned int, this results in unpredictable behavior when vq->vring.used->idx
wraps around.

This patch corrects this by changing last_used_idx to the correct type.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Anthony Liguori 2007-11-07 15:49:24 -06:00 committed by Rusty Russell
parent 4d125de3a5
commit 1bc4953ed4

View file

@ -53,7 +53,7 @@ struct vring_virtqueue
unsigned int num_added;
/* Last used index we've seen. */
unsigned int last_used_idx;
u16 last_used_idx;
/* How to notify other side. FIXME: commonalize hcalls! */
void (*notify)(struct virtqueue *vq);