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authorStephen Hemminger <shemminger@vyatta.com>2009-03-27 00:38:45 -0700
committerDavid S. Miller <davem@davemloft.net>2009-03-27 00:38:45 -0700
commit54dc79fe0d895758bdaa1dcf8512d3d21263d105 (patch)
tree8a6e73c9e3a227f420bd258d538dd525f3955f9c /drivers/net/gianfar.c
parentaf_rose/x25: Sanity check the maximum user frame size (diff)
downloadlinux-dev-54dc79fe0d895758bdaa1dcf8512d3d21263d105.tar.xz
linux-dev-54dc79fe0d895758bdaa1dcf8512d3d21263d105.zip
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: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/gianfar.c')
-rw-r--r--drivers/net/gianfar.c46
1 files changed, 24 insertions, 22 deletions
diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 9d81e7a48dba..a7a67376615b 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -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)) {
- lstatus |= BD_LFLAG(TXBD_TOE);
- gfar_tx_checksum(skb, fcb);
- }
+ 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 */