target/linux/generic/patches-3.3/654-avoid_skb_cow_realloc.patch

   1 --- a/include/linux/skbuff.h
   2 +++ b/include/linux/skbuff.h
   3 @@ -1850,12 +1850,15 @@ static inline int skb_clone_writable(con
   4  static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
   5                             int cloned)
   6  {
   7 +       unsigned int alloc_headroom = headroom;
   8         int delta = 0;
   9
  10         if (headroom < NET_SKB_PAD)
  11 -               headroom = NET_SKB_PAD;
  12 -       if (headroom > skb_headroom(skb))
  13 -               delta = headroom - skb_headroom(skb);
  14 +               alloc_headroom = NET_SKB_PAD;
  15 +       if (headroom > skb_headroom(skb) ||
  16 +           (cloned && alloc_headroom > skb_headroom(skb))) {
  17 +               delta = alloc_headroom - skb_headroom(skb);
  18 +       }
  19
  20         if (delta || cloned)
  21                 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,