1 files changed, 5 insertions, 7 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 743016baa048..f33c9dddaa12 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -642,7 +642,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
  * eventually). The difference is that pulled data not copied, but
  * immediately discarded.
  */
-static unsigned char *__pskb_trim_head(struct sk_buff *skb, int len)
+static void __pskb_trim_head(struct sk_buff *skb, int len)
 {
         int i, k, eat;
 
@@ -667,7 +667,6 @@ static unsigned char *__pskb_trim_head(struct sk_buff *skb, int len)
         skb->tail = skb->data;
         skb->data_len -= len;
         skb->len = skb->data_len;
-        return skb->tail;
 }
 
 int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
@@ -676,12 +675,11 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
             pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
                 return -ENOMEM;
 
-        if (len <= skb_headlen(skb)) {
+        /* If len == headlen, we avoid __skb_pull to preserve alignment. */
+        if (unlikely(len < skb_headlen(skb)))
                 __skb_pull(skb, len);
-        } else {
-                if (__pskb_trim_head(skb, len-skb_headlen(skb)) == NULL)
-                        return -ENOMEM;
-        }
+        else
+                __pskb_trim_head(skb, len - skb_headlen(skb));
 
         TCP_SKB_CB(skb)->seq += len;
         skb->ip_summed = CHECKSUM_HW;