diff options
Diffstat (limited to 'target/linux/generic/pending-4.4/030-7-kaweth-use-skb_cow_head-to-deal-with-cloned-skbs.patch')
| -rw-r--r-- | target/linux/generic/pending-4.4/030-7-kaweth-use-skb_cow_head-to-deal-with-cloned-skbs.patch | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/target/linux/generic/pending-4.4/030-7-kaweth-use-skb_cow_head-to-deal-with-cloned-skbs.patch b/target/linux/generic/pending-4.4/030-7-kaweth-use-skb_cow_head-to-deal-with-cloned-skbs.patch new file mode 100644 index 0000000..541c694 --- /dev/null +++ b/target/linux/generic/pending-4.4/030-7-kaweth-use-skb_cow_head-to-deal-with-cloned-skbs.patch @@ -0,0 +1,43 @@ +From 39fba7835aacda65284a86e611774cbba71dac20 Mon Sep 17 00:00:00 2001 +From: Eric Dumazet <edumazet@google.com> +Date: Wed, 19 Apr 2017 09:59:26 -0700 +Subject: [PATCH] kaweth: use skb_cow_head() to deal with cloned skbs + +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: Eric Dumazet <edumazet@google.com> +Cc: James Hughes <james.hughes@raspberrypi.org> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + drivers/net/usb/kaweth.c | 18 ++++++------------ + 1 file changed, 6 insertions(+), 12 deletions(-) + +--- a/drivers/net/usb/kaweth.c ++++ b/drivers/net/usb/kaweth.c +@@ -812,18 +812,12 @@ static netdev_tx_t kaweth_start_xmit(str + } + + /* 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); |