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: 's avatarEric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: 's avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4307a871
......@@ -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 */
if (skb_cloned(skb) || skb_headroom(skb) < 2) {
/* no such luck - we make our own */
struct sk_buff *copied_skb;
copied_skb = skb_copy_expand(skb, 2, 0, GFP_ATOMIC);
dev_kfree_skb_irq(skb);
skb = copied_skb;
if (!copied_skb) {
kaweth->stats.tx_errors++;
netif_start_queue(net);
spin_unlock_irq(&kaweth->device_lock);
return NETDEV_TX_OK;
}
if (skb_cow_head(skb, 2)) {
kaweth->stats.tx_errors++;
netif_start_queue(net);
spin_unlock_irq(&kaweth->device_lock);
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
private_header = (__le16 *)__skb_push(skb, 2);
......
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