udp: preserve head state for IP_CMSG_PASSSEC

[karo-tx-linux.git] / include / net / udp.h

diff --git a/include/net/udp.h b/include/net/udp.h
index 972ce4baab6b2a4b0539624d1a671c632d77514c..56ce2d2a612d33fedaf8372faddd0a1d205bc64d 100644 (file)
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -305,33 +305,44 @@ struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
 /* UDP uses skb->dev_scratch to cache as much information as possible and avoid
  * possibly multiple cache miss on dequeue()
  */
-#if BITS_PER_LONG == 64
-
-/* truesize, len and the bit needed to compute skb_csum_unnecessary will be on
- * cold cache lines at recvmsg time.
- * skb->len can be stored on 16 bits since the udp header has been already
- * validated and pulled.
- */
 struct udp_dev_scratch {
-       u32 truesize;
+       /* skb->truesize and the stateless bit are embedded in a single field;
+        * do not use a bitfield since the compiler emits better/smaller code
+        * this way
+        */
+       u32 _tsize_state;
+
+#if BITS_PER_LONG == 64
+       /* len and the bit needed to compute skb_csum_unnecessary
+        * will be on cold cache lines at recvmsg time.
+        * skb->len can be stored on 16 bits since the udp header has been
+        * already validated and pulled.
+        */
        u16 len;
        bool is_linear;
        bool csum_unnecessary;
+#endif
 };
 
+static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb)
+{
+       return (struct udp_dev_scratch *)&skb->dev_scratch;
+}
+
+#if BITS_PER_LONG == 64
 static inline unsigned int udp_skb_len(struct sk_buff *skb)
 {
-       return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;
+       return udp_skb_scratch(skb)->len;
 }
 
 static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
 {
-       return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;
+       return udp_skb_scratch(skb)->csum_unnecessary;
 }
 
 static inline bool udp_skb_is_linear(struct sk_buff *skb)
 {
-       return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;
+       return udp_skb_scratch(skb)->is_linear;
 }
 
 #else