tracing: Allow events to share their print functions

Multiple events may use the same method to print their data.
Instead of having all events have a pointer to their print funtions,
the trace_event structure now points to a trace_event_functions structure
that will hold the way to print ouf the event.

The event itself is now passed to the print function to let the print
function know what kind of event it should print.

This opens the door to consolidating the way several events print
their output.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init
4900446	1049028	 861512	6810986	 67ed6a	vmlinux.preprint

This change slightly increases the size but is needed for the next change.

v3: Fix the branch tracer events to handle this change.

v2: Fix the new function graph tracer event calls to handle this change.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

4 files changed, 32 insertions, 14 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 393a8394df0..4f77932b098 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -70,18 +70,25 @@ struct trace_iterator {
 };
 
 
+struct trace_event;
+
 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
-					      int flags);
-struct trace_event {
-	struct hlist_node	node;
-	struct list_head	list;
-	int			type;
+				      int flags, struct trace_event *event);
+
+struct trace_event_functions {
 	trace_print_func	trace;
 	trace_print_func	raw;
 	trace_print_func	hex;
 	trace_print_func	binary;
 };
 
+struct trace_event {
+	struct hlist_node		node;
+	struct list_head		list;
+	int				type;
+	struct trace_event_functions	*funcs;
+};
+
 extern int register_ftrace_event(struct trace_event *event);
 extern int unregister_ftrace_event(struct trace_event *event);
 
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 211c704a71e..f7256770a20 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -125,9 +125,12 @@ extern struct ftrace_event_class event_class_syscall_exit;
 	static struct syscall_metadata __syscall_meta_##sname;		\
 	static struct ftrace_event_call					\
 	__attribute__((__aligned__(4))) event_enter_##sname;		\
-	static struct trace_event enter_syscall_print_##sname = {	\
+	static struct trace_event_functions enter_syscall_print_funcs_##sname = { \
 		.trace                  = print_syscall_enter,		\
 	};								\
+	static struct trace_event enter_syscall_print_##sname = {	\
+		.funcs                  = &enter_syscall_print_funcs_##sname, \
+	};								\
 	static struct ftrace_event_call __used				\
 	  __attribute__((__aligned__(4)))				\
 	  __attribute__((section("_ftrace_events")))			\
@@ -142,9 +145,12 @@ extern struct ftrace_event_class event_class_syscall_exit;
 	static struct syscall_metadata __syscall_meta_##sname;		\
 	static struct ftrace_event_call					\
 	__attribute__((__aligned__(4))) event_exit_##sname;		\
-	static struct trace_event exit_syscall_print_##sname = {	\
+	static struct trace_event_functions exit_syscall_print_funcs_##sname = { \
 		.trace                  = print_syscall_exit,		\
 	};								\
+	static struct trace_event exit_syscall_print_##sname = {	\
+		.funcs                  = &exit_syscall_print_funcs_##sname, \
+	};								\
 	static struct ftrace_event_call __used				\
 	  __attribute__((__aligned__(4)))				\
 	  __attribute__((section("_ftrace_events")))			\
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index e7eb33420b0..51ed7f3568a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -239,7 +239,8 @@ ftrace_raw_output_id_##call(int event_id, const char *name,		\
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)			\
 static notrace enum print_line_t					\
-ftrace_raw_output_##name(struct trace_iterator *iter, int flags)	\
+ftrace_raw_output_##name(struct trace_iterator *iter, int flags,	\
+			 struct trace_event *event)			\
 {									\
 	return ftrace_raw_output_id_##template(event_##name.id,		\
 					       #name, iter, flags);	\
@@ -248,7 +249,8 @@ ftrace_raw_output_##name(struct trace_iterator *iter, int flags)	\
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
 static notrace enum print_line_t					\
-ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
+ftrace_raw_output_##call(struct trace_iterator *iter, int flags,	\
+			 struct trace_event *event)			\
 {									\
 	struct trace_seq *s = &iter->seq;				\
 	struct ftrace_raw_##template *field;				\
@@ -531,11 +533,12 @@ ftrace_raw_event_##call(void *__data, proto)				\
 
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, call, proto, args)			\
-									\
-static struct trace_event ftrace_event_type_##call = {			\
+static struct trace_event_functions ftrace_event_type_funcs_##call = {	\
 	.trace			= ftrace_raw_output_##call,		\
 };									\
-									\
+static struct trace_event ftrace_event_type_##call = {			\
+	.funcs			= &ftrace_event_type_funcs_##call,	\
+};									\
 static inline void ftrace_test_probe_##call(void)			\
 {									\
 	check_trace_callback_type_##call(ftrace_raw_event_##template);	\
diff --git a/include/trace/syscall.h b/include/trace/syscall.h
index 39647743cd9..257e08960d7 100644
--- a/include/trace/syscall.h
+++ b/include/trace/syscall.h
@@ -42,8 +42,10 @@ extern int reg_event_syscall_exit(struct ftrace_event_call *call);
 extern void unreg_event_syscall_exit(struct ftrace_event_call *call);
 extern int
 ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s);
-enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags);
-enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags);
+enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags,
+				      struct trace_event *event);
+enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags,
+				     struct trace_event *event);
 #endif
 
 #ifdef CONFIG_PERF_EVENTS