ibmveth: Fix issue with DMA mapping failure

descs[].fields.address is 32bit which truncates any dma mapping
errors so dma_mapping_error() fails to catch it.

Use a dma_addr_t to do the comparison. With this patch I was able
to transfer many gigabytes of data with IOMMU fault injection set
at 10% probability.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> # v2.6.37+
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index dcf65d8f10d2ad2a54f2b62b1dd20128666045e1..5b8b411d5a80f64afb2c409f6ce8e7da76845dca 100644 (file)
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -930,6 +930,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
        union ibmveth_buf_desc descs[6];
        int last, i;
        int force_bounce = 0;
+       dma_addr_t dma_addr;
 
        /*
         * veth handles a maximum of 6 segments including the header, so
@@ -994,17 +995,16 @@ retry_bounce:
        }
 
        /* Map the header */
-       descs[0].fields.address = dma_map_single(&adapter->vdev->dev, skb->data,
-                                                skb_headlen(skb),
-                                                DMA_TO_DEVICE);
-       if (dma_mapping_error(&adapter->vdev->dev, descs[0].fields.address))
+       dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
+                                 skb_headlen(skb), DMA_TO_DEVICE);
+       if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
                goto map_failed;
 
        descs[0].fields.flags_len = desc_flags | skb_headlen(skb);
+       descs[0].fields.address = dma_addr;
 
        /* Map the frags */
        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-               unsigned long dma_addr;
                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
                dma_addr = dma_map_page(&adapter->vdev->dev, frag->page,