[PATCH] [NET] print skb pointer in truesize bug

[PATCH] [NET] print skb pointer in truesize bug

[Johannes Berg]

While debugging the mac80211 truesize problem I always wished
that I knew exactly which skb showed the problem, this makes
skb_truesize_bug() print out the pointer.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/core/skbuff.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- everything.orig/net/core/skbuff.c	2008-05-01 12:53:09.000000000 +0200
+++ everything/net/core/skbuff.c	2008-05-01 12:53:31.000000000 +0200
@@ -152,8 +152,8 @@ void skb_under_panic(struct sk_buff *skb
 void skb_truesize_bug(struct sk_buff *skb)
 {
 	printk(KERN_ERR "SKB BUG: Invalid truesize (%u) "
-	       "len=%u, sizeof(sk_buff)=%Zd\n",
-	       skb->truesize, skb->len, sizeof(struct sk_buff));
+	       "len=%u, sizeof(sk_buff)=%Zd, skb=0x%p\n",
+	       skb->truesize, skb->len, sizeof(struct sk_buff), skb);
 }
 EXPORT_SYMBOL(skb_truesize_bug);
 

Re: [PATCH] [NET] print skb pointer in truesize bug

[David Miller]

From: Johannes Berg <johannes@sipsolutions.net>
Date: Thu, 01 May 2008 13:00:56 +0200

> While debugging the mac80211 truesize problem I always wished
> that I knew exactly which skb showed the problem, this makes
> skb_truesize_bug() print out the pointer.
> 
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

This information only is useful relative to something else.
Ie. another debugging message that prints out the SKB pointer
and with which you can try and compare things.

I assume you're adding such things while you try to debug
this, and like those local changes, this hack can stay local
to your tree too.