Commit 49cf68d7 authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman

kaweth: use skb_cow_head() to deal with cloned skbs

commit 39fba783 upstream.

We can use skb_cow_head() to properly deal with clones,
especially the ones coming from TCP stack that allow their head being
modified. This avoids a copy.
Signed-off-by: default avatarEric Dumazet <>
Cc: James Hughes <>
Signed-off-by: default avatarDavid S. Miller <>
Signed-off-by: default avatarLinus Walleij <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 4307a871
...@@ -812,18 +812,12 @@ static netdev_tx_t kaweth_start_xmit(struct sk_buff *skb, ...@@ -812,18 +812,12 @@ static netdev_tx_t kaweth_start_xmit(struct sk_buff *skb,
} }
/* We now decide whether we can put our special header into the sk_buff */ /* We now decide whether we can put our special header into the sk_buff */
if (skb_cloned(skb) || skb_headroom(skb) < 2) { if (skb_cow_head(skb, 2)) {
/* no such luck - we make our own */ kaweth->stats.tx_errors++;
struct sk_buff *copied_skb; netif_start_queue(net);
copied_skb = skb_copy_expand(skb, 2, 0, GFP_ATOMIC); spin_unlock_irq(&kaweth->device_lock);
dev_kfree_skb_irq(skb); dev_kfree_skb_any(skb);
skb = copied_skb; return NETDEV_TX_OK;
if (!copied_skb) {
return NETDEV_TX_OK;
} }
private_header = (__le16 *)__skb_push(skb, 2); private_header = (__le16 *)__skb_push(skb, 2);
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