Messages in this thread | | | Subject | Re: [PATCH 5/8] xen/netfront: read response from backend only once | From | Jan Beulich <> | Date | Mon, 17 May 2021 16:20:21 +0200 |
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On 13.05.2021 12:02, Juergen Gross wrote: > In order to avoid problems in case the backend is modifying a response > on the ring page while the frontend has already seen it, just read the > response into a local buffer in one go and then operate on that buffer > only. > > Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com> with one remark:
> @@ -830,24 +830,22 @@ static int xennet_get_extras(struct netfront_queue *queue, > break; > } > > - extra = (struct xen_netif_extra_info *) > - RING_GET_RESPONSE(&queue->rx, ++cons); > + RING_COPY_RESPONSE(&queue->rx, ++cons, &extra); > > - if (unlikely(!extra->type || > - extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { > + if (unlikely(!extra.type || > + extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { > if (net_ratelimit()) > dev_warn(dev, "Invalid extra type: %d\n", > - extra->type); > + extra.type); > err = -EINVAL; > } else { > - memcpy(&extras[extra->type - 1], extra, > - sizeof(*extra)); > + memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
Maybe take the opportunity and switch to (type safe) structure assignment?
Jan
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