[PATCH 3.19 007/123] net: fec: fix receive VLAN CTAG HW acceleration issue

3.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nimrod Andy <redacted>

[ Upstream commit af5cbc9822f6bbe399925760a4d5ee82c21f258c ]

The current driver support receive VLAN CTAG HW acceleration feature
(NETIF_F_HW_VLAN_CTAG_RX) through software simulation. There calls the
api .skb_copy_to_linear_data_offset() to skip the VLAN tag, but there
have overlap between the two memory data point range. The patch just fix
the issue.

V2:
Michael Grzeschik suggest to use memmove() instead of skb_copy_to_linear_data_offset().

Reported-by: Michael Grzeschik <redacted>
Fixes: 1b7bde6d659d ("net: fec: implement rx_copybreak to improve rx performance")
Signed-off-by: Fugang Duan <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/freescale/fec_main.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c

@@ -1448,8 +1448,7 @@ fec_enet_rx_queue(struct net_device *nde
 
 			vlan_packet_rcvd = true;
 
-			skb_copy_to_linear_data_offset(skb, VLAN_HLEN,
-						       data, (2 * ETH_ALEN));
+			memmove(skb->data + VLAN_HLEN, data, ETH_ALEN * 2);
 			skb_pull(skb, VLAN_HLEN);
 		}