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Commit 2b499381 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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ftrace: Have global_ops store the functions that are to be traced 



This is a step towards each ops structure defining its own set
of functions to trace. As the current code with pid's and such
are specific to the global_ops, it is restructured to be used
with the global ops.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent bd69c30b

kernel/trace/ftrace.c

+53 −16
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; 
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;

ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;

ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;

static struct ftrace_ops global_ops;



/*

 * Traverse the ftrace_list, invoking all entries.  The reason that we
@@ -153,7 +154,7 @@ static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) 
}

#endif



static void update_ftrace_function(void)

static void update_global_ops(void)

{

	ftrace_func_t func;
@@ -173,6 +174,18 @@ static void update_ftrace_function(void) 
		set_ftrace_pid_function(func);

		func = ftrace_pid_func;

	}



	global_ops.func = func;

}



static void update_ftrace_function(void)

{

	ftrace_func_t func;



	update_global_ops();



	func = global_ops.func;



#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST

	ftrace_trace_function = func;

#else
@@ -181,24 +194,19 @@ static void update_ftrace_function(void) 
#endif

}



static int __register_ftrace_function(struct ftrace_ops *ops)

static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)

{

	ops->next = ftrace_list;

	ops->next = *list;

	/*

	 * We are entering ops into the ftrace_list but another

	 * CPU might be walking that list. We need to make sure

	 * the ops->next pointer is valid before another CPU sees

	 * the ops pointer included into the ftrace_list.

	 */

	rcu_assign_pointer(ftrace_list, ops);



	if (ftrace_enabled)

		update_ftrace_function();



	return 0;

	rcu_assign_pointer(*list, ops);

}



static int __unregister_ftrace_function(struct ftrace_ops *ops)

static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)

{

	struct ftrace_ops **p;
@@ -206,13 +214,12 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) 
	 * If we are removing the last function, then simply point

	 * to the ftrace_stub.

	 */

	if (ftrace_list == ops && ops->next == &ftrace_list_end) {

		ftrace_trace_function = ftrace_stub;

		ftrace_list = &ftrace_list_end;

	if (*list == ops && ops->next == &ftrace_list_end) {

		*list = &ftrace_list_end;

		return 0;

	}



	for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)

	for (p = list; *p != &ftrace_list_end; p = &(*p)->next)

		if (*p == ops)

			break;
@@ -220,7 +227,37 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) 
		return -1;



	*p = (*p)->next;

	return 0;

}



static int __register_ftrace_function(struct ftrace_ops *ops)

{

	if (ftrace_disabled)

		return -ENODEV;



	if (FTRACE_WARN_ON(ops == &global_ops))

		return -EINVAL;



	add_ftrace_ops(&ftrace_list, ops);

	if (ftrace_enabled)

		update_ftrace_function();



	return 0;

}



static int __unregister_ftrace_function(struct ftrace_ops *ops)

{

	int ret;



	if (ftrace_disabled)

		return -ENODEV;



	if (FTRACE_WARN_ON(ops == &global_ops))

		return -EINVAL;



	ret = remove_ftrace_ops(&ftrace_list, ops);

	if (ret < 0)

		return ret;

	if (ftrace_enabled)

		update_ftrace_function();
@@ -894,7 +931,7 @@ enum { 
	FTRACE_OPS_FL_ENABLED		= 1,

};



struct ftrace_ops global_ops = {

static struct ftrace_ops global_ops = {

	.func			= ftrace_stub,

	.notrace_hash		= EMPTY_HASH,

	.filter_hash		= EMPTY_HASH,
@@ -3263,7 +3300,7 @@ void __init ftrace_init(void) 


#else



struct ftrace_ops global_ops = {

static struct ftrace_ops global_ops = {

	.func			= ftrace_stub,

};