net: Use skb_checksum_start_offset()

Replace skb->csum_start - skb_headroom(skb) with skb_checksum_start_offset().

Note for usb/smsc95xx: skb->data - skb->head == skb_headroom(skb).

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 42567279843e..21845affea13 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -504,8 +504,7 @@ static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
 
         if (skb->ip_summed == CHECKSUM_PARTIAL) {
                 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-                vnet_hdr->csum_start = skb->csum_start -
-                                        skb_headroom(skb);
+                vnet_hdr->csum_start = skb_checksum_start_offset(skb);
                 vnet_hdr->csum_offset = skb->csum_offset;
         } /* else everything is zero */