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authorSantiago Leon <santil@us.ibm.com>2008-08-20 13:09:19 -0600
committerJeff Garzik <jgarzik@redhat.com>2008-08-27 05:36:57 -0400
commit45e15bb734e4e559ab32f26196e44d5cf1417f10 (patch)
treee71322bc295822ad97af55b0298668eab093cfec /drivers/net
parentc213f286f2cf6590f83f541f66a625ee8d20c6f4 (diff)
ibmveth: fix bad UDP checksums
This patch fixes a ibmveth bug where bad UDP checksums are being transmitted when checksum offloading is enabled. The hypervisor does checksum offloading only on TCP packets, so ibmveth calls skb_checksum_help() for any other protocol. The bug happens because the packet is being modified after the DMA map, so we would need a memory barrier before making the hypervisor call. Reordering the code so that the DMA map happens after skb_checksum_help() has the additional advantage of fixing a DMA map leak if skb_checksum_help() where to fail. Signed-off-by: Santiago Leon <santil@us.ibm.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ibmveth.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index a03fe1fb61c..c2d57f83608 100644
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -904,8 +904,6 @@ static int ibmveth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
unsigned long data_dma_addr;
desc.fields.flags_len = IBMVETH_BUF_VALID | skb->len;
- data_dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
- skb->len, DMA_TO_DEVICE);
if (skb->ip_summed == CHECKSUM_PARTIAL &&
ip_hdr(skb)->protocol != IPPROTO_TCP && skb_checksum_help(skb)) {
@@ -924,6 +922,8 @@ static int ibmveth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
buf[1] = 0;
}
+ data_dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
+ skb->len, DMA_TO_DEVICE);
if (dma_mapping_error(&adapter->vdev->dev, data_dma_addr)) {
if (!firmware_has_feature(FW_FEATURE_CMO))
ibmveth_error_printk("tx: unable to map xmit buffer\n");
@@ -932,6 +932,7 @@ static int ibmveth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
desc.fields.address = adapter->bounce_buffer_dma;
tx_map_failed++;
used_bounce = 1;
+ wmb();
} else
desc.fields.address = data_dma_addr;