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path: root/drivers/net/xen-netback/netback.c
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Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r--drivers/net/xen-netback/netback.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 0020b2e8c279..315dfc6ea297 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1453,7 +1453,7 @@ int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
void *addr;
struct xen_netif_tx_sring *txs;
struct xen_netif_rx_sring *rxs;
-
+ RING_IDX rsp_prod, req_prod;
int err = -ENOMEM;
err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
@@ -1462,7 +1462,14 @@ int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
goto err;
txs = (struct xen_netif_tx_sring *)addr;
- BACK_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
+ rsp_prod = READ_ONCE(txs->rsp_prod);
+ req_prod = READ_ONCE(txs->req_prod);
+
+ BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
+
+ err = -EIO;
+ if (req_prod - rsp_prod > RING_SIZE(&queue->tx))
+ goto err;
err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
&rx_ring_ref, 1, &addr);
@@ -1470,7 +1477,14 @@ int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
goto err;
rxs = (struct xen_netif_rx_sring *)addr;
- BACK_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
+ rsp_prod = READ_ONCE(rxs->rsp_prod);
+ req_prod = READ_ONCE(rxs->req_prod);
+
+ BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
+
+ err = -EIO;
+ if (req_prod - rsp_prod > RING_SIZE(&queue->rx))
+ goto err;
return 0;