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Commit 1310b544 authored by Lothar Waßmann's avatar Lothar Waßmann Committed by David S. Miller
Browse files

net: fec: fix regression on i.MX28 introduced by rx_copybreak support 



commit 1b7bde6d ("net: fec: implement rx_copybreak to improve rx performance")
introduced a regression for i.MX28. The swap_buffer() function doing
the endian conversion of the received data on i.MX28 may access memory
beyond the actual packet size in the DMA buffer. fec_enet_copybreak()
does not copy those bytes, so that the last bytes of a packet may be
filled with invalid data after swapping.
This will likely lead to checksum errors on received packets.
E.g. when trying to mount an NFS rootfs:
UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36

Do the byte swapping and copying to the new skb in one go if
necessary.

Signed-off-by: default avatarLothar Waßmann <LW@KARO-electronics.de>
Tested-by: default avatarFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1f562310

drivers/net/ethernet/freescale/fec_main.c

+19 −4
Original line number Original line Diff line number Diff line
@@ -298,6 +298,16 @@ static void *swap_buffer(void *bufaddr, int len) 
	return bufaddr;

	return bufaddr;

}

}





static void swap_buffer2(void *dst_buf, void *src_buf, int len)

{

	int i;

	unsigned int *src = src_buf;

	unsigned int *dst = dst_buf;



	for (i = 0; i < len; i += 4, src++, dst++)

		*dst = swab32p(src);

}



static void fec_dump(struct net_device *ndev)

static void fec_dump(struct net_device *ndev)

{

{

	struct fec_enet_private *fep = netdev_priv(ndev);

	struct fec_enet_private *fep = netdev_priv(ndev);
@@ -1307,7 +1317,7 @@ fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff 
}

}





static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,

static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,

			       struct bufdesc *bdp, u32 length)

			       struct bufdesc *bdp, u32 length, bool swap)

{

{

	struct  fec_enet_private *fep = netdev_priv(ndev);

	struct  fec_enet_private *fep = netdev_priv(ndev);

	struct sk_buff *new_skb;

	struct sk_buff *new_skb;
@@ -1322,7 +1332,10 @@ static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb, 
	dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,

	dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,

				FEC_ENET_RX_FRSIZE - fep->rx_align,

				FEC_ENET_RX_FRSIZE - fep->rx_align,

				DMA_FROM_DEVICE);

				DMA_FROM_DEVICE);

	if (!swap)

		memcpy(new_skb->data, (*skb)->data, length);

		memcpy(new_skb->data, (*skb)->data, length);

	else

		swap_buffer2(new_skb->data, (*skb)->data, length);

	*skb = new_skb;

	*skb = new_skb;





	return true;

	return true;
@@ -1352,6 +1365,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) 
	u16	vlan_tag;

	u16	vlan_tag;

	int	index = 0;

	int	index = 0;

	bool	is_copybreak;

	bool	is_copybreak;

	bool	need_swap = id_entry->driver_data & FEC_QUIRK_SWAP_FRAME;





#ifdef CONFIG_M532x

#ifdef CONFIG_M532x

	flush_cache_all();

	flush_cache_all();
@@ -1415,7 +1429,8 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) 
		 * include that when passing upstream as it messes up

		 * include that when passing upstream as it messes up

		 * bridging applications.

		 * bridging applications.

		 */

		 */

		is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4);

		is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4,

						  need_swap);

		if (!is_copybreak) {

		if (!is_copybreak) {

			skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);

			skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);

			if (unlikely(!skb_new)) {

			if (unlikely(!skb_new)) {
@@ -1430,7 +1445,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) 
		prefetch(skb->data - NET_IP_ALIGN);

		prefetch(skb->data - NET_IP_ALIGN);

		skb_put(skb, pkt_len - 4);

		skb_put(skb, pkt_len - 4);

		data = skb->data;

		data = skb->data;

		if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)

		if (!is_copybreak && need_swap)

			swap_buffer(data, pkt_len);

			swap_buffer(data, pkt_len);





		/* Extract the enhanced buffer descriptor */

		/* Extract the enhanced buffer descriptor */