On Fri, 28 Aug 2009, Neil Horman wrote:

quoted

quoted

 
 /*
  * Tracepoint for free an sk_buff:

@@ -42,16 +43,35 @@ TRACE_EVENT(skb_copy_datagram_iovec,
 	TP_ARGS(skb, len),
 
 	TP_STRUCT__entry(
-		__field(	const void *,		skbaddr		)
+		__field(	const struct sk_buff *,	skb		)
 		__field(	int,			len		)
+		__field(	int,			anid		)
+		__field(	int,			cnid		)
+		__field(	int,			rx_queue	)
+		__dynamic_array(char,		name,	IFNAMSIZ	)

For string fields we have a __string macro:

		__string(	char,			name		)

Yeah, I was going to use that, but I ran into an issue, in that the __string
macro expects, as its second of two arguments, a pointer to a string with witch
to determine the dynamic arrays size.  The problem is that, if I'm to provide
that, I need to point it to skb->dev->name, and there is no guarantee that
skb->dev isn't NULL, at which point I think the use of string breaks down.  Note
below that I obtain the dev pointer by other means and check its validity prior
to assigning it.  If theres a better way to do this, please let me know.

Ah, OK I see the issue. The problem is the code that figures out the 
offset. It will always be calculated, and that would cause the skb->dev be 
evaluated and if NULL will cause an OOPS.

Yeah, keep the dynamic_array here then.

-- Steve