[NET]: Fix packet timestamping.

I've found the problem in general.  It affects any 64-bit
architecture.  The problem occurs when you change the system time.

Suppose that when you boot your system clock is forward by a day.
This gets recorded down in skb_tv_base.  You then wind the clock back
by a day.  From that point onwards the offset will be negative which
essentially overflows the 32-bit variables they're stored in.

In fact, why don't we just store the real time stamp in those 32-bit
variables? After all, we're not going to overflow for quite a while
yet.

When we do overflow, we'll need a better solution of course.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 5 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f80a287..0e9431b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -71,8 +71,6 @@
 static kmem_cache_t *skbuff_head_cache __read_mostly;
 static kmem_cache_t *skbuff_fclone_cache __read_mostly;
 
-struct timeval __read_mostly skb_tv_base;
-
 /*
  *	Keep out-of-line to prevent kernel bloat.
  *	__builtin_return_address is not used because it is not always
@@ -1708,8 +1706,6 @@ void __init skb_init(void)
 						NULL, NULL);
 	if (!skbuff_fclone_cache)
 		panic("cannot create skbuff cache");
-
-	do_gettimeofday(&skb_tv_base);
 }
 
 EXPORT_SYMBOL(___pskb_trim);
@@ -1743,4 +1739,3 @@ EXPORT_SYMBOL(skb_prepare_seq_read);
 EXPORT_SYMBOL(skb_seq_read);
 EXPORT_SYMBOL(skb_abort_seq_read);
 EXPORT_SYMBOL(skb_find_text);
-EXPORT_SYMBOL(skb_tv_base);