skb: Add inline helper for getting the skb end offset from head

With the recent changes for how we compute the skb truesize it occurs to me
we are probably going to have a lot of calls to skb_end_pointer -
skb->head.  Instead of running all over the place doing that it would make
more sense to just make it a separate inline skb_end_offset(skb) that way
we can return the correct value without having gcc having to do all the
optimization to cancel out skb->head - skb->head.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 6 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 17e4b1e1bf2c..2c35da818ef9 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -829,7 +829,7 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
 {
         int headerlen = skb_headroom(skb);
-        unsigned int size = (skb_end_pointer(skb) - skb->head) + skb->data_len;
+        unsigned int size = skb_end_offset(skb) + skb->data_len;
         struct sk_buff *n = alloc_skb(size, gfp_mask);
 
         if (!n)
@@ -930,7 +930,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 {
         int i;
         u8 *data;
-        int size = nhead + (skb_end_pointer(skb) - skb->head) + ntail;
+        int size = nhead + skb_end_offset(skb) + ntail;
         long off;
 
         BUG_ON(nhead < 0);
@@ -2727,14 +2727,13 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
                         if (unlikely(!nskb))
                                 goto err;
 
-                        hsize = skb_end_pointer(nskb) - nskb->head;
+                        hsize = skb_end_offset(nskb);
                         if (skb_cow_head(nskb, doffset + headroom)) {
                                 kfree_skb(nskb);
                                 goto err;
                         }
 
-                        nskb->truesize += skb_end_pointer(nskb) - nskb->head -
-                                          hsize;
+                        nskb->truesize += skb_end_offset(nskb) - hsize;
                         skb_release_head_state(nskb);
                         __skb_push(nskb, doffset);
                 } else {
@@ -2883,7 +2882,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
                 skb_frag_size_sub(frag, offset);
 
                 /* all fragments truesize : remove (head size + sk_buff) */
-                delta_truesize = skb->truesize - SKB_TRUESIZE(skb_end_pointer(skb) - skb->head);
+                delta_truesize = skb->truesize -
+                                 SKB_TRUESIZE(skb_end_offset(skb));
 
                 skb->truesize -= skb->data_len;
                 skb->len -= skb->data_len;