Re: [Xen-devel] [PATCH 3/3] xen/blkback: Check for insane amounts of request on the ring.

Jan Beulich
2013-01-28T11:07:53Z

>>> On 25.01.13 at 19:43, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote:
> @@ -764,6 +768,9 @@ __do_block_io_op(struct xen_blkif *blkif)
> rp = blk_rings->common.sring->req_prod;
> rmb(); /* Ensure we see queued requests up to 'rp'. */
>
> + if (RING_REQUEST_PROD_OVERFLOW(&blk_rings->common, rp, rc))
> + return -EACCES;

Actually I wonder whether we need the new macro at all: It seems
to me that using RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rp)
here would achieve the same effect.

Jan

> +
> while (rc != rp) {
>
> if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc))