tracing, net, skb tracepoint: make skb tracepoint use the TRACE_EVENT…

…() macro

TRACE_EVENT is a more generic way to define a tracepoint.
Doing so adds these new capabilities to this tracepoint:

  - zero-copy and per-cpu splice() tracing
  - binary tracing without printf overhead
  - structured logging records exposed under /debug/tracing/events
  - trace events embedded in function tracer output and other plugins
  - user-defined, per tracepoint filter expressions

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Steven Rostedt ;" <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DD90D2.5020604@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/trace/skb.h

@@ -4,8 +4,6 @@
 #include <linux/skbuff.h>
 #include <linux/tracepoint.h>
 
-DECLARE_TRACE(kfree_skb,
-	TP_PROTO(struct sk_buff *skb, void *location),
-	TP_ARGS(skb, location));
+#include <trace/skb_event_types.h>
 
 #endif

include/trace/skb_event_types.h

@@ -0,0 +1,38 @@
+
+/* use <trace/skb.h> instead */
+#ifndef TRACE_EVENT
+# error Do not include this file directly.
+# error Unless you know what you are doing.
+#endif
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM skb
+
+/*
+ * Tracepoint for free an sk_buff:
+ */
+TRACE_EVENT(kfree_skb,
+
+	TP_PROTO(struct sk_buff *skb, void *location),
+
+	TP_ARGS(skb, location),
+
+	TP_STRUCT__entry(
+		__field(	void *,		skbaddr		)
+		__field(	unsigned short,	protocol	)
+		__field(	void *,		location	)
+	),
+
+	TP_fast_assign(
+		__entry->skbaddr = skb;
+		if (skb) {
+			__entry->protocol = ntohs(skb->protocol);
+		}
+		__entry->location = location;
+	),
+
+	TP_printk("skbaddr=%p protocol=%u location=%p",
+		__entry->skbaddr, __entry->protocol, __entry->location)
+);
+
+#undef TRACE_SYSTEM

include/trace/trace_event_types.h

@@ -3,3 +3,4 @@
 #include <trace/sched_event_types.h>
 #include <trace/irq_event_types.h>
 #include <trace/lockdep_event_types.h>
+#include <trace/skb_event_types.h>

include/trace/trace_events.h

@@ -3,3 +3,4 @@
 #include <trace/sched.h>
 #include <trace/irq.h>
 #include <trace/lockdep.h>
+#include <trace/skb.h>