Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1bc4953e authored by Anthony Liguori's avatar Anthony Liguori Committed by Rusty Russell
Browse files

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: default avatarAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 4d125de3

drivers/virtio/virtio_ring.c

+1 −1
Original line number Diff line number Diff line
@@ -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);