[PATCH net-next v5] net: linux/skbuff.h: combine SKB_EXTENSIONS + KCOV handling

[Randy Dunlap]

The previous Kconfig patch led to some other build errors as
reported by the 0day bot and my own overnight build testing.

These are all in <linux/skbuff.h> when KCOV is enabled but
SKB_EXTENSIONS is not enabled, so fix those by combining those conditions
in the header file.

Fixes: 6370cc3bbd8a ("net: add kcov handle to skb extensions")
Fixes: 85ce50d337d1 ("net: kcov: don't select SKB_EXTENSIONS when there is no NET")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Cc: Aleksandr Nogikh <nogikh@xxxxxxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-next@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Cc: Florian Westphal <fw@xxxxxxxxx>
---
v2: (as suggested by Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>)
  drop an extraneous space in a comment;
  use CONFIG_SKB_EXTENSIONS instead of CONFIG_NET;
v3, v4: dropped
v5: drop a redundant IS_ENABLED(CONFIG_SKB_EXTENSIONS) in an enum;

 include/linux/skbuff.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-next-20201113.orig/include/linux/skbuff.h
+++ linux-next-20201113/include/linux/skbuff.h
@@ -4608,7 +4608,7 @@ static inline void skb_reset_redirect(st
 #endif
 }
 
-#ifdef CONFIG_KCOV
+#if IS_ENABLED(CONFIG_KCOV) && IS_ENABLED(CONFIG_SKB_EXTENSIONS)
 static inline void skb_set_kcov_handle(struct sk_buff *skb,
 				       const u64 kcov_handle)
 {
@@ -4636,7 +4636,7 @@ static inline u64 skb_get_kcov_handle(st
 static inline void skb_set_kcov_handle(struct sk_buff *skb,
 				       const u64 kcov_handle) { }
 static inline u64 skb_get_kcov_handle(struct sk_buff *skb) { return 0; }
-#endif /* CONFIG_KCOV */
+#endif /* CONFIG_KCOV && CONFIG_SKB_EXTENSIONS */
 
 #endif	/* __KERNEL__ */
 #endif	/* _LINUX_SKBUFF_H */