net: clean up skb headers code

commit 1a37e412a0225fcba5587 (net: Use 16bits for *_headers
fields of struct skbuff) converts skb->*_header to u16,
some #if NET_SKBUFF_DATA_USES_OFFSET are now useless,
and to be safe, we could just use "X = (typeof(X)) ~0U;"
as suggested by David.

Cc: David S. Miller <davem@davemloft.net>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 7 insertions, 13 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5f931191cf57..b9997907a0f1 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1593,7 +1593,7 @@ static inline void skb_set_inner_mac_header(struct sk_buff *skb,
 }
 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
 {
-        return skb->transport_header != ~0U;
+        return skb->transport_header != (typeof(skb->transport_header))~0U;
 }
 
 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
@@ -1636,7 +1636,7 @@ static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
 
 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
 {
-        return skb->mac_header != ~0U;
+        return skb->mac_header != (typeof(skb->mac_header))~0U;
 }
 
 static inline void skb_reset_mac_header(struct sk_buff *skb)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f45de077ab9e..6b1b52c5593b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -199,9 +199,7 @@ struct sk_buff *__alloc_skb_head(gfp_t gfp_mask, int node)
         skb->truesize = sizeof(struct sk_buff);
         atomic_set(&skb->users, 1);
 
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        skb->mac_header = (__u16) ~0U;
-#endif
+        skb->mac_header = (typeof(skb->mac_header))~0U;
 out:
         return skb;
 }
@@ -275,10 +273,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
         skb->data = data;
         skb_reset_tail_pointer(skb);
         skb->end = skb->tail + size;
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        skb->mac_header = (__u16) ~0U;
-        skb->transport_header = (__u16) ~0U;
-#endif
+        skb->mac_header = (typeof(skb->mac_header))~0U;
+        skb->transport_header = (typeof(skb->transport_header))~0U;
 
         /* make sure we initialize shinfo sequentially */
         shinfo = skb_shinfo(skb);
@@ -344,10 +340,8 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size)
         skb->data = data;
         skb_reset_tail_pointer(skb);
         skb->end = skb->tail + size;
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        skb->mac_header = (__u16) ~0U;
-        skb->transport_header = (__u16) ~0U;
-#endif
+        skb->mac_header = (typeof(skb->mac_header))~0U;
+        skb->transport_header = (typeof(skb->transport_header))~0U;
 
         /* make sure we initialize shinfo sequentially */
         shinfo = skb_shinfo(skb);