tracing/events: Add ftrace_event_call param to define_fields()

This parameter is needed by syscall events to add define_fields()
handler.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAF90.6060801@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/ftrace_event.h

@@ -118,7 +118,7 @@ struct ftrace_event_call {
 	int			(*raw_init)(void);
 	int			(*show_format)(struct ftrace_event_call *call,
 					       struct trace_seq *s);
-	int			(*define_fields)(void);
+	int			(*define_fields)(struct ftrace_event_call *);
 	struct list_head	fields;
 	int			filter_active;
 	struct event_filter	*filter;

include/trace/ftrace.h

@@ -294,10 +294,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
 #undef TRACE_EVENT
 #define TRACE_EVENT(call, proto, args, tstruct, func, print)		\
 int									\
-ftrace_define_fields_##call(void)					\
+ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
 {									\
 	struct ftrace_raw_##call field;					\
-	struct ftrace_event_call *event_call = &event_##call;		\
 	int ret;							\
 									\
 	__common_field(int, type, 1);					\

kernel/trace/trace_events.c

@@ -941,7 +941,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 					  id);
 
 	if (call->define_fields) {
-		ret = call->define_fields();
+		ret = call->define_fields(call);
 		if (ret < 0) {
 			pr_warning("Could not initialize trace point"
 				   " events/%s\n", call->name);

kernel/trace/trace_export.c

@@ -119,7 +119,7 @@ ftrace_format_##call(struct ftrace_event_call *unused,			\
 
 #undef TRACE_EVENT_FORMAT
 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\
-int ftrace_define_fields_##call(void);					\
+int ftrace_define_fields_##call(struct ftrace_event_call *event_call);	\
 static int ftrace_raw_init_event_##call(void);				\
 									\
 struct ftrace_event_call __used						\
@@ -184,9 +184,8 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
 #undef TRACE_EVENT_FORMAT
 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\
 int									\
-ftrace_define_fields_##call(void)					\
+ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
 {									\
-	struct ftrace_event_call *event_call = &event_##call;		\
 	struct args field;						\
 	int ret;							\
 									\