1 files changed, 45 insertions, 17 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 0e4851b..8b43ddc 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -847,6 +847,13 @@ static void netbk_tx_err(struct xenvif *vif,
 	xenvif_put(vif);
 }
 
+static void netbk_fatal_tx_err(struct xenvif *vif)
+{
+	netdev_err(vif->dev, "fatal error; disabling device\n");
+	xenvif_carrier_off(vif);
+	xenvif_put(vif);
+}
+
 static int netbk_count_requests(struct xenvif *vif,
 				struct xen_netif_tx_request *first,
 				struct xen_netif_tx_request *txp,
@@ -860,19 +867,22 @@ static int netbk_count_requests(struct xenvif *vif,
 
 	do {
 		if (frags >= work_to_do) {
-			netdev_dbg(vif->dev, "Need more frags\n");
+			netdev_err(vif->dev, "Need more frags\n");
+			netbk_fatal_tx_err(vif);
 			return -frags;
 		}
 
 		if (unlikely(frags >= MAX_SKB_FRAGS)) {
-			netdev_dbg(vif->dev, "Too many frags\n");
+			netdev_err(vif->dev, "Too many frags\n");
+			netbk_fatal_tx_err(vif);
 			return -frags;
 		}
 
 		memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + frags),
 		       sizeof(*txp));
 		if (txp->size > first->size) {
-			netdev_dbg(vif->dev, "Frags galore\n");
+			netdev_err(vif->dev, "Frag is bigger than frame.\n");
+			netbk_fatal_tx_err(vif);
 			return -frags;
 		}
 
@@ -880,8 +890,9 @@ static int netbk_count_requests(struct xenvif *vif,
 		frags++;
 
 		if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
-			netdev_dbg(vif->dev, "txp->offset: %x, size: %u\n",
+			netdev_err(vif->dev, "txp->offset: %x, size: %u\n",
 				 txp->offset, txp->size);
+			netbk_fatal_tx_err(vif);
 			return -frags;
 		}
 	} while ((txp++)->flags & XEN_NETTXF_more_data);
@@ -1057,7 +1068,8 @@ static int xen_netbk_get_extras(struct xenvif *vif,
 
 	do {
 		if (unlikely(work_to_do-- <= 0)) {
-			netdev_dbg(vif->dev, "Missing extra info\n");
+			netdev_err(vif->dev, "Missing extra info\n");
+			netbk_fatal_tx_err(vif);
 			return -EBADR;
 		}
 
@@ -1066,8 +1078,9 @@ static int xen_netbk_get_extras(struct xenvif *vif,
 		if (unlikely(!extra.type ||
 			     extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
 			vif->tx.req_cons = ++cons;
-			netdev_dbg(vif->dev,
+			netdev_err(vif->dev,
 				   "Invalid extra type: %d\n", extra.type);
+			netbk_fatal_tx_err(vif);
 			return -EINVAL;
 		}
 
@@ -1083,13 +1096,15 @@ static int netbk_set_skb_gso(struct xenvif *vif,
 			     struct xen_netif_extra_info *gso)
 {
 	if (!gso->u.gso.size) {
-		netdev_dbg(vif->dev, "GSO size must not be zero.\n");
+		netdev_err(vif->dev, "GSO size must not be zero.\n");
+		netbk_fatal_tx_err(vif);
 		return -EINVAL;
 	}
 
 	/* Currently only TCPv4 S.O. is supported. */
 	if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
-		netdev_dbg(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
+		netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
+		netbk_fatal_tx_err(vif);
 		return -EINVAL;
 	}
 
@@ -1226,9 +1241,25 @@ static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk)
 
 		/* Get a netif from the list with work to do. */
 		vif = poll_net_schedule_list(netbk);
+		/* This can sometimes happen because the test of
+		 * list_empty(net_schedule_list) at the top of the
+		 * loop is unlocked.  Just go back and have another
+		 * look.
+		 */
 		if (!vif)
 			continue;
 
+		if (vif->tx.sring->req_prod - vif->tx.req_cons >
+		    XEN_NETIF_TX_RING_SIZE) {
+			netdev_err(vif->dev,
+				   "Impossible number of requests. "
+				   "req_prod %d, req_cons %d, size %ld\n",
+				   vif->tx.sring->req_prod, vif->tx.req_cons,
+				   XEN_NETIF_TX_RING_SIZE);
+			netbk_fatal_tx_err(vif);
+			continue;
+		}
+
 		RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, work_to_do);
 		if (!work_to_do) {
 			xenvif_put(vif);
@@ -1256,17 +1287,14 @@ static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk)
 			work_to_do = xen_netbk_get_extras(vif, extras,
 							  work_to_do);
 			idx = vif->tx.req_cons;
-			if (unlikely(work_to_do < 0)) {
-				netbk_tx_err(vif, &txreq, idx);
+			if (unlikely(work_to_do < 0))
 				continue;
-			}
 		}
 
 		ret = netbk_count_requests(vif, &txreq, txfrags, work_to_do);
-		if (unlikely(ret < 0)) {
-			netbk_tx_err(vif, &txreq, idx - ret);
+		if (unlikely(ret < 0))
 			continue;
-		}
+
 		idx += ret;
 
 		if (unlikely(txreq.size < ETH_HLEN)) {
@@ -1278,11 +1306,11 @@ static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk)
 
 		/* No crossing a page as the payload mustn't fragment. */
 		if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
-			netdev_dbg(vif->dev,
+			netdev_err(vif->dev,
 				   "txreq.offset: %x, size: %u, end: %lu\n",
 				   txreq.offset, txreq.size,
 				   (txreq.offset&~PAGE_MASK) + txreq.size);
-			netbk_tx_err(vif, &txreq, idx);
+			netbk_fatal_tx_err(vif);
 			continue;
 		}
 
@@ -1310,8 +1338,8 @@ static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk)
 			gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
 
 			if (netbk_set_skb_gso(vif, skb, gso)) {
+				/* Failure in netbk_set_skb_gso is fatal. */
 				kfree_skb(skb);
-				netbk_tx_err(vif, &txreq, idx);
 				continue;
 			}
 		}