[PATCH v3] include/linux/skbuff.h: using '(__u16) ~0U' instead of '~0U'
From: Chen Gang <hidden>
Date: 2013-06-05 02:55:23
Also in:
lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Both 'transport_header' and 'mac_header' are __u16, which are never equal to '~0U'. So need use '(__u16) ~0U' instead of '~0U'. The related warning (with EXTRA_CFLAGS=-W ARCH=m68k for allmodconfig) include/linux/skbuff.h:1587:2: warning: comparison is always true due to limited range of data type [-Wtype-limits] ... Use meaningful macro instead of hard code number, and better to initialize 'skb->transport_header' in __alloc_skb_head(), too. Signed-off-by: Chen Gang <redacted> --- include/linux/skbuff.h | 6 ++++-- net/core/skbuff.c | 11 ++++++----- 2 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5f93119..3314911 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -40,6 +40,8 @@ #define CHECKSUM_COMPLETE 2 #define CHECKSUM_PARTIAL 3 +#define SKB_HEADER_OFFSET_UNSET ((__u16) ~0U) + #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ ~(SMP_CACHE_BYTES - 1)) #define SKB_WITH_OVERHEAD(X) \
@@ -1593,7 +1595,7 @@ 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 != SKB_HEADER_OFFSET_UNSET; } static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
@@ -1636,7 +1638,7 @@ 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 != SKB_HEADER_OFFSET_UNSET; } static inline void skb_reset_mac_header(struct sk_buff *skb)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f45de07..6808433 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -200,7 +200,8 @@ struct sk_buff *__alloc_skb_head(gfp_t gfp_mask, int node) atomic_set(&skb->users, 1); #ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->mac_header = (__u16) ~0U; + skb->mac_header = SKB_HEADER_OFFSET_UNSET; + skb->transport_header = SKB_HEADER_OFFSET_UNSET; #endif out: return skb;
@@ -276,8 +277,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, 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; + skb->mac_header = SKB_HEADER_OFFSET_UNSET; + skb->transport_header = SKB_HEADER_OFFSET_UNSET; #endif /* make sure we initialize shinfo sequentially */
@@ -345,8 +346,8 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) 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; + skb->mac_header = SKB_HEADER_OFFSET_UNSET; + skb->transport_header = SKB_HEADER_OFFSET_UNSET; #endif /* make sure we initialize shinfo sequentially */
--
1.7.7.6