tracing: Pull up calls to trace_define_common_fields()

Call trace_define_common_fields() in event_create_dir() only.
This avoids trace events to handle it from their define_fields
callbacks and shrinks the kernel code size:

   text    data     bss     dec     hex filename
5346802 1961864 7103260 14411926         dbe896 vmlinux.o.old
5345151 1961864 7103260 14410275         dbe223 vmlinux.o
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <4B1DC49C.8000107@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

include/linux/ftrace_event.h

@@ -159,7 +159,6 @@ enum {
 };
 
 extern int trace_event_raw_init(struct ftrace_event_call *call);
-extern int trace_define_common_fields(struct ftrace_event_call *call);
 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 			      const char *name, int offset, int size,
 			      int is_signed, int filter_type);

include/trace/ftrace.h

@@ -436,10 +436,6 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
 	struct ftrace_raw_##call field;					\
 	int ret;							\
 									\
-	ret = trace_define_common_fields(event_call);			\
-	if (ret)							\
-		return ret;						\
-									\
 	tstruct;							\
 									\
 	return ret;							\

kernel/trace/trace_events.c

@@ -78,7 +78,7 @@ EXPORT_SYMBOL_GPL(trace_define_field);
 	if (ret)							\
 		return ret;
 
-int trace_define_common_fields(struct ftrace_event_call *call)
+static int trace_define_common_fields(struct ftrace_event_call *call)
 {
 	int ret;
 	struct trace_entry ent;
@@ -91,7 +91,6 @@ int trace_define_common_fields(struct ftrace_event_call *call)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(trace_define_common_fields);
 
 void trace_destroy_fields(struct ftrace_event_call *call)
 {
@@ -927,7 +926,9 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 		 		  id);
 
 	if (call->define_fields) {
-		ret = call->define_fields(call);
+		ret = trace_define_common_fields(call);
+		if (!ret)
+			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

@@ -184,10 +184,6 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
 	struct struct_name field;					\
 	int ret;							\
 									\
-	ret = trace_define_common_fields(event_call);			\
-	if (ret)							\
-		return ret;						\
-									\
 	tstruct;							\
 									\
 	return ret;							\

kernel/trace/trace_kprobe.c

@@ -1113,10 +1113,6 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
 	struct kprobe_trace_entry field;
 	struct trace_probe *tp = (struct trace_probe *)event_call->data;
 
-	ret = trace_define_common_fields(event_call);
-	if (!ret)
-		return ret;
-
 	DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
 	DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
 	/* Set argument names as fields */
@@ -1131,10 +1127,6 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
 	struct kretprobe_trace_entry field;
 	struct trace_probe *tp = (struct trace_probe *)event_call->data;
 
-	ret = trace_define_common_fields(event_call);
-	if (!ret)
-		return ret;
-
 	DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
 	DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
 	DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);

kernel/trace/trace_syscalls.c

@@ -217,10 +217,6 @@ int syscall_enter_define_fields(struct ftrace_event_call *call)
 	int i;
 	int offset = offsetof(typeof(trace), args);
 
-	ret = trace_define_common_fields(call);
-	if (ret)
-		return ret;
-
 	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
 	if (ret)
 		return ret;
@@ -241,10 +237,6 @@ int syscall_exit_define_fields(struct ftrace_event_call *call)
 	struct syscall_trace_exit trace;
 	int ret;
 
-	ret = trace_define_common_fields(call);
-	if (ret)
-		return ret;
-
 	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
 	if (ret)
 		return ret;