Merge tag 'for-linus-4.4-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:
 - XSA-155 security fixes to backend drivers.
 - XSA-157 security fixes to pciback.

* tag 'for-linus-4.4-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-pciback: fix up cleanup path when alloc fails
  xen/pciback: Don't allow MSI-X ops if PCI_COMMAND_MEMORY is not set.
  xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled.
  xen/pciback: Do not install an IRQ handler for MSI interrupts.
  xen/pciback: Return error on XEN_PCI_OP_enable_msix when device has MSI or MSI-X enabled
  xen/pciback: Return error on XEN_PCI_OP_enable_msi when device has MSI or MSI-X enabled
  xen/pciback: Save xen_pci_op commands before processing it
  xen-scsiback: safely copy requests
  xen-blkback: read from indirect descriptors only once
  xen-blkback: only read request operation from shared ring once
  xen-netback: use RING_COPY_REQUEST() throughout
  xen-netback: don't use last request to determine minimum Tx credit
  xen: Add RING_COPY_REQUEST()
  xen/x86/pvh: Use HVM's flush_tlb_others op
  xen: Resume PMU from non-atomic context
  xen/events/fifo: Consume unprocessed events when a CPU dies

1 files changed, 15 insertions, 19 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index e481f3710bd3..1049c34e7d43 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -258,18 +258,18 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
 						 struct netrx_pending_operations *npo)
 {
 	struct xenvif_rx_meta *meta;
-	struct xen_netif_rx_request *req;
+	struct xen_netif_rx_request req;
 
-	req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+	RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 
 	meta = npo->meta + npo->meta_prod++;
 	meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
 	meta->gso_size = 0;
 	meta->size = 0;
-	meta->id = req->id;
+	meta->id = req.id;
 
 	npo->copy_off = 0;
-	npo->copy_gref = req->gref;
+	npo->copy_gref = req.gref;
 
 	return meta;
 }
@@ -424,7 +424,7 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 	struct xenvif *vif = netdev_priv(skb->dev);
 	int nr_frags = skb_shinfo(skb)->nr_frags;
 	int i;
-	struct xen_netif_rx_request *req;
+	struct xen_netif_rx_request req;
 	struct xenvif_rx_meta *meta;
 	unsigned char *data;
 	int head = 1;
@@ -443,15 +443,15 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 
 	/* Set up a GSO prefix descriptor, if necessary */
 	if ((1 << gso_type) & vif->gso_prefix_mask) {
-		req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+		RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 		meta = npo->meta + npo->meta_prod++;
 		meta->gso_type = gso_type;
 		meta->gso_size = skb_shinfo(skb)->gso_size;
 		meta->size = 0;
-		meta->id = req->id;
+		meta->id = req.id;
 	}
 
-	req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+	RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 	meta = npo->meta + npo->meta_prod++;
 
 	if ((1 << gso_type) & vif->gso_mask) {
@@ -463,9 +463,9 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 	}
 
 	meta->size = 0;
-	meta->id = req->id;
+	meta->id = req.id;
 	npo->copy_off = 0;
-	npo->copy_gref = req->gref;
+	npo->copy_gref = req.gref;
 
 	data = skb->data;
 	while (data < skb_tail_pointer(skb)) {
@@ -679,9 +679,7 @@ static void tx_add_credit(struct xenvif_queue *queue)
 	 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
 	 * Otherwise the interface can seize up due to insufficient credit.
 	 */
-	max_burst = RING_GET_REQUEST(&queue->tx, queue->tx.req_cons)->size;
-	max_burst = min(max_burst, 131072UL);
-	max_burst = max(max_burst, queue->credit_bytes);
+	max_burst = max(131072UL, queue->credit_bytes);
 
 	/* Take care that adding a new chunk of credit doesn't wrap to zero. */
 	max_credit = queue->remaining_credit + queue->credit_bytes;
@@ -711,7 +709,7 @@ static void xenvif_tx_err(struct xenvif_queue *queue,
 		spin_unlock_irqrestore(&queue->response_lock, flags);
 		if (cons == end)
 			break;
-		txp = RING_GET_REQUEST(&queue->tx, cons++);
+		RING_COPY_REQUEST(&queue->tx, cons++, txp);
 	} while (1);
 	queue->tx.req_cons = cons;
 }
@@ -778,8 +776,7 @@ static int xenvif_count_requests(struct xenvif_queue *queue,
 		if (drop_err)
 			txp = &dropped_tx;
 
-		memcpy(txp, RING_GET_REQUEST(&queue->tx, cons + slots),
-		       sizeof(*txp));
+		RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
 
 		/* If the guest submitted a frame >= 64 KiB then
 		 * first->size overflowed and following slots will
@@ -1112,8 +1109,7 @@ static int xenvif_get_extras(struct xenvif_queue *queue,
 			return -EBADR;
 		}
 
-		memcpy(&extra, RING_GET_REQUEST(&queue->tx, cons),
-		       sizeof(extra));
+		RING_COPY_REQUEST(&queue->tx, cons, &extra);
 		if (unlikely(!extra.type ||
 			     extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
 			queue->tx.req_cons = ++cons;
@@ -1322,7 +1318,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
 		idx = queue->tx.req_cons;
 		rmb(); /* Ensure that we see the request before we copy it. */
-		memcpy(&txreq, RING_GET_REQUEST(&queue->tx, idx), sizeof(txreq));
+		RING_COPY_REQUEST(&queue->tx, idx, &txreq);
 
 		/* Credit-based scheduling. */
 		if (txreq.size > queue->remaining_credit &&