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Commit 54dc79fe authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

gianfar: fix headroom expansion code 



The code that was added to increase headroom was wrong.
It doesn't handle the case where gfar_add_fcb() changes the skb.
Better to do check at start of transmit (outside of lock), where
error handling is better anyway.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 83e0bbcb

drivers/net/gianfar.c

+24 −22
Original line number Diff line number Diff line
@@ -1239,19 +1239,9 @@ static int gfar_enet_open(struct net_device *dev) 
	return err;

}



static inline struct txfcb *gfar_add_fcb(struct sk_buff **skbp)

static inline struct txfcb *gfar_add_fcb(struct sk_buff *skb)

{

	struct txfcb *fcb;

	struct sk_buff *skb = *skbp;



	if (unlikely(skb_headroom(skb) < GMAC_FCB_LEN)) {

		struct sk_buff *old_skb = skb;

		skb = skb_realloc_headroom(old_skb, GMAC_FCB_LEN);

		if (!skb)

			return NULL;

		dev_kfree_skb_any(old_skb);

	}

	fcb = (struct txfcb *)skb_push(skb, GMAC_FCB_LEN);

	struct txfcb *fcb = (struct txfcb *)skb_push(skb, GMAC_FCB_LEN);

	cacheable_memzero(fcb, GMAC_FCB_LEN);



	return fcb;
@@ -1320,6 +1310,20 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	base = priv->tx_bd_base;



	/* make space for additional header */

	if (skb_headroom(skb) < GMAC_FCB_LEN) {

		struct sk_buff *skb_new;



		skb_new = skb_realloc_headroom(skb, GMAC_FCB_LEN);

		if (!skb_new) {

			dev->stats.tx_errors++;

			kfree(skb);

			return NETDEV_TX_OK;

		}

		kfree_skb(skb);

		skb = skb_new;

	}



	/* total number of fragments in the SKB */

	nr_frags = skb_shinfo(skb)->nr_frags;
@@ -1372,20 +1376,18 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	/* Set up checksumming */

	if (CHECKSUM_PARTIAL == skb->ip_summed) {

		fcb = gfar_add_fcb(&skb);

		if (likely(fcb != NULL)) {

		fcb = gfar_add_fcb(skb);

		lstatus |= BD_LFLAG(TXBD_TOE);

		gfar_tx_checksum(skb, fcb);

	}

	}



	if (priv->vlgrp && vlan_tx_tag_present(skb)) {

		if (unlikely(NULL == fcb))

			fcb = gfar_add_fcb(&skb);

		if (likely(fcb != NULL)) {

		if (unlikely(NULL == fcb)) {

			fcb = gfar_add_fcb(skb);

			lstatus |= BD_LFLAG(TXBD_TOE);

			gfar_tx_vlan(skb, fcb);

		}



		gfar_tx_vlan(skb, fcb);

	}



	/* setup the TxBD length and buffer pointer for the first BD */
@@ -1433,7 +1435,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	/* Unlock priv */

	spin_unlock_irqrestore(&priv->txlock, flags);



	return 0;

	return NETDEV_TX_OK;

}



/* Stops the kernel queue, and halts the controller */