From b944a8585cf3a23ad910d246e7c07b42ff218cb9 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Thu, 22 Apr 2010 10:35:55 -0400
Subject: [PATCH] --- yaml --- r: 199135 b: refs/heads/master c:
 2e33af029556cb8bd22bf4f86f42d540249177ea h: refs/heads/master i:   199133:
 9178b2d204b580a38fbf9e863e18ace866d2716e   199131:
 174845f0cbd74fad2a1d728f1f317eb40a31e1e6   199127:
 697c202047d8caf6e3f9c5abf52a4437c91d8ce7   199119:
 eaae6ef0379e2f2c8d403006d0d8197b5d21f57e   199103:
 c9df853880018139ad37747511738e8c4681d47d v: v3

---
 [refs]                                   |  2 +-
 trunk/include/linux/ftrace_event.h       |  5 ++-
 trunk/include/linux/syscalls.h           | 14 ++++---
 trunk/include/trace/ftrace.h             | 11 +++---
 trunk/include/trace/syscall.h            |  4 +-
 trunk/kernel/trace/trace.h               |  3 ++
 trunk/kernel/trace/trace_events.c        | 48 ++++++++++++++++++------
 trunk/kernel/trace/trace_events_filter.c | 10 +++--
 trunk/kernel/trace/trace_export.c        | 14 +++----
 trunk/kernel/trace/trace_kprobe.c        |  8 ++--
 trunk/kernel/trace/trace_syscalls.c      | 31 +++++++++++++--
 11 files changed, 103 insertions(+), 47 deletions(-)

diff --git a/[refs] b/[refs]
index 8438de699be5..8bc8613d9893 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2239291aeb0379fe47980b0e560e0eb9fd7e82ec
+refs/heads/master: 2e33af029556cb8bd22bf4f86f42d540249177ea
diff --git a/trunk/include/linux/ftrace_event.h b/trunk/include/linux/ftrace_event.h
index e665ed38b4bf..479c3c1876e6 100644
--- a/trunk/include/linux/ftrace_event.h
+++ b/trunk/include/linux/ftrace_event.h
@@ -130,6 +130,9 @@ struct ftrace_event_class {
 #endif
 	int			(*reg)(struct ftrace_event_call *event,
 				       enum trace_reg type);
+	int			(*define_fields)(struct ftrace_event_call *);
+	struct list_head	*(*get_fields)(struct ftrace_event_call *);
+	struct list_head	fields;
 };
 
 struct ftrace_event_call {
@@ -142,8 +145,6 @@ struct ftrace_event_call {
 	int			id;
 	const char		*print_fmt;
 	int			(*raw_init)(struct ftrace_event_call *);
-	int			(*define_fields)(struct ftrace_event_call *);
-	struct list_head	fields;
 	int			filter_active;
 	struct event_filter	*filter;
 	void			*mod;
diff --git a/trunk/include/linux/syscalls.h b/trunk/include/linux/syscalls.h
index e3348c4c22e8..fd0f1f248cd8 100644
--- a/trunk/include/linux/syscalls.h
+++ b/trunk/include/linux/syscalls.h
@@ -122,7 +122,7 @@ extern struct ftrace_event_class event_class_syscall_enter;
 extern struct ftrace_event_class event_class_syscall_exit;
 
 #define SYSCALL_TRACE_ENTER_EVENT(sname)				\
-	static const struct syscall_metadata __syscall_meta_##sname;	\
+	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 = {	\
@@ -136,12 +136,11 @@ extern struct ftrace_event_class event_class_syscall_exit;
 		.class			= &event_class_syscall_enter,	\
 		.event                  = &enter_syscall_print_##sname,	\
 		.raw_init		= init_syscall_trace,		\
-		.define_fields		= syscall_enter_define_fields,	\
 		.data			= (void *)&__syscall_meta_##sname,\
 	}
 
 #define SYSCALL_TRACE_EXIT_EVENT(sname)					\
-	static const struct syscall_metadata __syscall_meta_##sname;	\
+	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 = {	\
@@ -155,14 +154,13 @@ extern struct ftrace_event_class event_class_syscall_exit;
 		.class			= &event_class_syscall_exit,	\
 		.event                  = &exit_syscall_print_##sname,	\
 		.raw_init		= init_syscall_trace,		\
-		.define_fields		= syscall_exit_define_fields,	\
 		.data			= (void *)&__syscall_meta_##sname,\
 	}
 
 #define SYSCALL_METADATA(sname, nb)				\
 	SYSCALL_TRACE_ENTER_EVENT(sname);			\
 	SYSCALL_TRACE_EXIT_EVENT(sname);			\
-	static const struct syscall_metadata __used		\
+	static struct syscall_metadata __used			\
 	  __attribute__((__aligned__(4)))			\
 	  __attribute__((section("__syscalls_metadata")))	\
 	  __syscall_meta_##sname = {				\
@@ -172,12 +170,14 @@ extern struct ftrace_event_class event_class_syscall_exit;
 		.args		= args_##sname,			\
 		.enter_event	= &event_enter_##sname,		\
 		.exit_event	= &event_exit_##sname,		\
+		.enter_fields	= LIST_HEAD_INIT(__syscall_meta_##sname.enter_fields), \
+		.exit_fields	= LIST_HEAD_INIT(__syscall_meta_##sname.exit_fields), \
 	};
 
 #define SYSCALL_DEFINE0(sname)					\
 	SYSCALL_TRACE_ENTER_EVENT(_##sname);			\
 	SYSCALL_TRACE_EXIT_EVENT(_##sname);			\
-	static const struct syscall_metadata __used		\
+	static struct syscall_metadata __used			\
 	  __attribute__((__aligned__(4)))			\
 	  __attribute__((section("__syscalls_metadata")))	\
 	  __syscall_meta__##sname = {				\
@@ -185,6 +185,8 @@ extern struct ftrace_event_class event_class_syscall_exit;
 		.nb_args 	= 0,				\
 		.enter_event	= &event_enter__##sname,	\
 		.exit_event	= &event_exit__##sname,		\
+		.enter_fields	= LIST_HEAD_INIT(__syscall_meta__##sname.enter_fields), \
+		.exit_fields	= LIST_HEAD_INIT(__syscall_meta__##sname.exit_fields), \
 	};							\
 	asmlinkage long sys_##sname(void)
 #else
diff --git a/trunk/include/trace/ftrace.h b/trunk/include/trace/ftrace.h
index 26d132418f92..c7e3bcd5d52f 100644
--- a/trunk/include/trace/ftrace.h
+++ b/trunk/include/trace/ftrace.h
@@ -430,6 +430,9 @@ static inline notrace int ftrace_get_offsets_##call(			\
  *
  * static struct ftrace_event_class __used event_class_<template> = {
  *	.system			= "<system>",
+ *	.define_fields		= ftrace_define_fields_<call>,
+ *	.fields			= LIST_HEAD_INIT(event_class_##call.fields), \
+ *	.probe			= ftrace_raw_event_##call,		\
  * };
  *
  * static struct ftrace_event_call __used
@@ -438,10 +441,8 @@ static inline notrace int ftrace_get_offsets_##call(			\
  *	.name			= "<call>",
  *	.class			= event_class_<template>,
  *	.raw_init		= trace_event_raw_init,
- *	.regfunc		= ftrace_raw_reg_event_<call>,
- *	.unregfunc		= ftrace_raw_unreg_event_<call>,
+ *	.event			= &ftrace_event_type_<call>,
  *	.print_fmt		= print_fmt_<call>,
- *	.define_fields		= ftrace_define_fields_<call>,
  * };
  *
  */
@@ -563,6 +564,8 @@ _TRACE_PERF_PROTO(call, PARAMS(proto));					\
 static const char print_fmt_##call[] = print;				\
 static struct ftrace_event_class __used event_class_##call = {		\
 	.system			= __stringify(TRACE_SYSTEM),		\
+	.define_fields		= ftrace_define_fields_##call,		\
+	.fields			= LIST_HEAD_INIT(event_class_##call.fields),\
 	.probe			= ftrace_raw_event_##call,		\
 	_TRACE_PERF_INIT(call)						\
 };
@@ -578,7 +581,6 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
 	.event			= &ftrace_event_type_##call,		\
 	.raw_init		= trace_event_raw_init,			\
 	.print_fmt		= print_fmt_##template,			\
-	.define_fields		= ftrace_define_fields_##template,	\
 };
 
 #undef DEFINE_EVENT_PRINT
@@ -594,7 +596,6 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
 	.event			= &ftrace_event_type_##call,		\
 	.raw_init		= trace_event_raw_init,			\
 	.print_fmt		= print_fmt_##call,			\
-	.define_fields		= ftrace_define_fields_##template,	\
 }
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
diff --git a/trunk/include/trace/syscall.h b/trunk/include/trace/syscall.h
index e5e5f48dbfb3..39647743cd95 100644
--- a/trunk/include/trace/syscall.h
+++ b/trunk/include/trace/syscall.h
@@ -25,6 +25,8 @@ struct syscall_metadata {
 	int		nb_args;
 	const char	**types;
 	const char	**args;
+	struct list_head enter_fields;
+	struct list_head exit_fields;
 
 	struct ftrace_event_call *enter_event;
 	struct ftrace_event_call *exit_event;
@@ -34,8 +36,6 @@ struct syscall_metadata {
 extern unsigned long arch_syscall_addr(int nr);
 extern int init_syscall_trace(struct ftrace_event_call *call);
 
-extern int syscall_enter_define_fields(struct ftrace_event_call *call);
-extern int syscall_exit_define_fields(struct ftrace_event_call *call);
 extern int reg_event_syscall_enter(struct ftrace_event_call *call);
 extern void unreg_event_syscall_enter(struct ftrace_event_call *call);
 extern int reg_event_syscall_exit(struct ftrace_event_call *call);
diff --git a/trunk/kernel/trace/trace.h b/trunk/kernel/trace/trace.h
index 911e9864e94a..c88c563a59a5 100644
--- a/trunk/kernel/trace/trace.h
+++ b/trunk/kernel/trace/trace.h
@@ -794,6 +794,9 @@ extern void print_subsystem_event_filter(struct event_subsystem *system,
 					 struct trace_seq *s);
 extern int filter_assign_type(const char *type);
 
+struct list_head *
+trace_get_fields(struct ftrace_event_call *event_call);
+
 static inline int
 filter_check_discard(struct ftrace_event_call *call, void *rec,
 		     struct ring_buffer *buffer,
diff --git a/trunk/kernel/trace/trace_events.c b/trunk/kernel/trace/trace_events.c
index 19d1eb0a7188..acc0f55742c3 100644
--- a/trunk/kernel/trace/trace_events.c
+++ b/trunk/kernel/trace/trace_events.c
@@ -29,11 +29,23 @@ DEFINE_MUTEX(event_mutex);
 
 LIST_HEAD(ftrace_events);
 
+struct list_head *
+trace_get_fields(struct ftrace_event_call *event_call)
+{
+	if (!event_call->class->get_fields)
+		return &event_call->class->fields;
+	return event_call->class->get_fields(event_call);
+}
+
 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)
 {
 	struct ftrace_event_field *field;
+	struct list_head *head;
+
+	if (WARN_ON(!call->class))
+		return 0;
 
 	field = kzalloc(sizeof(*field), GFP_KERNEL);
 	if (!field)
@@ -56,7 +68,8 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,
 	field->size = size;
 	field->is_signed = is_signed;
 
-	list_add(&field->link, &call->fields);
+	head = trace_get_fields(call);
+	list_add(&field->link, head);
 
 	return 0;
 
@@ -94,8 +107,10 @@ static int trace_define_common_fields(struct ftrace_event_call *call)
 void trace_destroy_fields(struct ftrace_event_call *call)
 {
 	struct ftrace_event_field *field, *next;
+	struct list_head *head;
 
-	list_for_each_entry_safe(field, next, &call->fields, link) {
+	head = trace_get_fields(call);
+	list_for_each_entry_safe(field, next, head, link) {
 		list_del(&field->link);
 		kfree(field->type);
 		kfree(field->name);
@@ -111,7 +126,6 @@ int trace_event_raw_init(struct ftrace_event_call *call)
 	if (!id)
 		return -ENODEV;
 	call->id = id;
-	INIT_LIST_HEAD(&call->fields);
 
 	return 0;
 }
@@ -537,6 +551,7 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 {
 	struct ftrace_event_call *call = filp->private_data;
 	struct ftrace_event_field *field;
+	struct list_head *head;
 	struct trace_seq *s;
 	int common_field_count = 5;
 	char *buf;
@@ -555,7 +570,8 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 	trace_seq_printf(s, "ID: %d\n", call->id);
 	trace_seq_printf(s, "format:\n");
 
-	list_for_each_entry_reverse(field, &call->fields, link) {
+	head = trace_get_fields(call);
+	list_for_each_entry_reverse(field, head, link) {
 		/*
 		 * Smartly shows the array type(except dynamic array).
 		 * Normal:
@@ -931,6 +947,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 		 const struct file_operations *filter,
 		 const struct file_operations *format)
 {
+	struct list_head *head;
 	int ret;
 
 	/*
@@ -957,14 +974,21 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 		 		  id);
 #endif
 
-	if (call->define_fields) {
-		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);
-			return ret;
+	if (call->class->define_fields) {
+		/*
+		 * Other events may have the same class. Only update
+		 * the fields if they are not already defined.
+		 */
+		head = trace_get_fields(call);
+		if (list_empty(head)) {
+			ret = trace_define_common_fields(call);
+			if (!ret)
+				ret = call->class->define_fields(call);
+			if (ret < 0) {
+				pr_warning("Could not initialize trace point"
+					   " events/%s\n", call->name);
+				return ret;
+			}
 		}
 		trace_create_file("filter", 0644, call->dir, call,
 				  filter);
diff --git a/trunk/kernel/trace/trace_events_filter.c b/trunk/kernel/trace/trace_events_filter.c
index ca329603d0bf..961f99b74bdd 100644
--- a/trunk/kernel/trace/trace_events_filter.c
+++ b/trunk/kernel/trace/trace_events_filter.c
@@ -500,8 +500,10 @@ static struct ftrace_event_field *
 find_event_field(struct ftrace_event_call *call, char *name)
 {
 	struct ftrace_event_field *field;
+	struct list_head *head;
 
-	list_for_each_entry(field, &call->fields, link) {
+	head = trace_get_fields(call);
+	list_for_each_entry(field, head, link) {
 		if (!strcmp(field->name, name))
 			return field;
 	}
@@ -625,7 +627,7 @@ static int init_subsystem_preds(struct event_subsystem *system)
 	int err;
 
 	list_for_each_entry(call, &ftrace_events, list) {
-		if (!call->define_fields)
+		if (!call->class || !call->class->define_fields)
 			continue;
 
 		if (strcmp(call->class->system, system->name) != 0)
@@ -644,7 +646,7 @@ static void filter_free_subsystem_preds(struct event_subsystem *system)
 	struct ftrace_event_call *call;
 
 	list_for_each_entry(call, &ftrace_events, list) {
-		if (!call->define_fields)
+		if (!call->class || !call->class->define_fields)
 			continue;
 
 		if (strcmp(call->class->system, system->name) != 0)
@@ -1249,7 +1251,7 @@ static int replace_system_preds(struct event_subsystem *system,
 	list_for_each_entry(call, &ftrace_events, list) {
 		struct event_filter *filter = call->filter;
 
-		if (!call->define_fields)
+		if (!call->class || !call->class->define_fields)
 			continue;
 
 		if (strcmp(call->class->system, system->name) != 0)
diff --git a/trunk/kernel/trace/trace_export.c b/trunk/kernel/trace/trace_export.c
index 7f16e2163817..e700a0c1803f 100644
--- a/trunk/kernel/trace/trace_export.c
+++ b/trunk/kernel/trace/trace_export.c
@@ -18,10 +18,6 @@
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM	ftrace
 
-struct ftrace_event_class event_class_ftrace = {
-	.system			= __stringify(TRACE_SYSTEM),
-};
-
 /* not needed for this file */
 #undef __field_struct
 #define __field_struct(type, item)
@@ -131,7 +127,7 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
 
 static int ftrace_raw_init_event(struct ftrace_event_call *call)
 {
-	INIT_LIST_HEAD(&call->fields);
+	INIT_LIST_HEAD(&call->class->fields);
 	return 0;
 }
 
@@ -159,15 +155,19 @@ static int ftrace_raw_init_event(struct ftrace_event_call *call)
 #undef FTRACE_ENTRY
 #define FTRACE_ENTRY(call, struct_name, type, tstruct, print)		\
 									\
+struct ftrace_event_class event_class_ftrace_##call = {			\
+	.system			= __stringify(TRACE_SYSTEM),		\
+	.define_fields		= ftrace_define_fields_##call,		\
+};									\
+									\
 struct ftrace_event_call __used						\
 __attribute__((__aligned__(4)))						\
 __attribute__((section("_ftrace_events"))) event_##call = {		\
 	.name			= #call,				\
 	.id			= type,					\
-	.class			= &event_class_ftrace,			\
+	.class			= &event_class_ftrace_##call,		\
 	.raw_init		= ftrace_raw_init_event,		\
 	.print_fmt		= print,				\
-	.define_fields		= ftrace_define_fields_##call,		\
 };									\
 
 #include "trace_entries.h"
diff --git a/trunk/kernel/trace/trace_kprobe.c b/trunk/kernel/trace/trace_kprobe.c
index f8af21a53f0c..b14bf745356f 100644
--- a/trunk/kernel/trace/trace_kprobe.c
+++ b/trunk/kernel/trace/trace_kprobe.c
@@ -1112,8 +1112,6 @@ static void probe_event_disable(struct ftrace_event_call *call)
 
 static int probe_event_raw_init(struct ftrace_event_call *event_call)
 {
-	INIT_LIST_HEAD(&event_call->fields);
-
 	return 0;
 }
 
@@ -1362,11 +1360,13 @@ static int register_probe_event(struct trace_probe *tp)
 	if (probe_is_return(tp)) {
 		tp->event.trace = print_kretprobe_event;
 		call->raw_init = probe_event_raw_init;
-		call->define_fields = kretprobe_event_define_fields;
+		INIT_LIST_HEAD(&call->class->fields);
+		call->class->define_fields = kretprobe_event_define_fields;
 	} else {
 		tp->event.trace = print_kprobe_event;
 		call->raw_init = probe_event_raw_init;
-		call->define_fields = kprobe_event_define_fields;
+		INIT_LIST_HEAD(&call->class->fields);
+		call->class->define_fields = kprobe_event_define_fields;
 	}
 	if (set_print_fmt(tp) < 0)
 		return -ENOMEM;
diff --git a/trunk/kernel/trace/trace_syscalls.c b/trunk/kernel/trace/trace_syscalls.c
index a21d366cae46..cceccf0d2e91 100644
--- a/trunk/kernel/trace/trace_syscalls.c
+++ b/trunk/kernel/trace/trace_syscalls.c
@@ -20,14 +20,37 @@ static int syscall_enter_register(struct ftrace_event_call *event,
 static int syscall_exit_register(struct ftrace_event_call *event,
 				 enum trace_reg type);
 
+static int syscall_enter_define_fields(struct ftrace_event_call *call);
+static int syscall_exit_define_fields(struct ftrace_event_call *call);
+
+static struct list_head *
+syscall_get_enter_fields(struct ftrace_event_call *call)
+{
+	struct syscall_metadata *entry = call->data;
+
+	return &entry->enter_fields;
+}
+
+static struct list_head *
+syscall_get_exit_fields(struct ftrace_event_call *call)
+{
+	struct syscall_metadata *entry = call->data;
+
+	return &entry->exit_fields;
+}
+
 struct ftrace_event_class event_class_syscall_enter = {
 	.system			= "syscalls",
-	.reg			= syscall_enter_register
+	.reg			= syscall_enter_register,
+	.define_fields		= syscall_enter_define_fields,
+	.get_fields		= syscall_get_enter_fields,
 };
 
 struct ftrace_event_class event_class_syscall_exit = {
 	.system			= "syscalls",
-	.reg			= syscall_exit_register
+	.reg			= syscall_exit_register,
+	.define_fields		= syscall_exit_define_fields,
+	.get_fields		= syscall_get_exit_fields,
 };
 
 extern unsigned long __start_syscalls_metadata[];
@@ -220,7 +243,7 @@ static void free_syscall_print_fmt(struct ftrace_event_call *call)
 		kfree(call->print_fmt);
 }
 
-int syscall_enter_define_fields(struct ftrace_event_call *call)
+static int syscall_enter_define_fields(struct ftrace_event_call *call)
 {
 	struct syscall_trace_enter trace;
 	struct syscall_metadata *meta = call->data;
@@ -243,7 +266,7 @@ int syscall_enter_define_fields(struct ftrace_event_call *call)
 	return ret;
 }
 
-int syscall_exit_define_fields(struct ftrace_event_call *call)
+static int syscall_exit_define_fields(struct ftrace_event_call *call)
 {
 	struct syscall_trace_exit trace;
 	int ret;