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Commit bd1a5c84 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Frederic Weisbecker
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tracing: Ftrace dynamic ftrace_event_call support 



Add dynamic ftrace_event_call support to ftrace. Trace engines can add
new ftrace_event_call to ftrace on the fly. Each operator function of
the call takes an ftrace_event_call data structure as an argument,
because these functions may be shared among several ftrace_event_calls.

Changes from v13:
 - Define remove_subsystem_dir() always (revirt a2ca5e03), because
   trace_remove_event_call() uses it.
 - Modify syscall tracer because of ftrace_event_call change.

[fweisbec@gmail.com: Fixed conflict against latest tracing/core]

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203453.31965.71901.stgit@localhost.localdomain>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent b1cf540f

include/linux/ftrace_event.h

+10 −9
Original line number Diff line number Diff line
@@ -112,12 +112,12 @@ struct ftrace_event_call { 
	struct dentry		*dir;

	struct trace_event	*event;

	int			enabled;

	int			(*regfunc)(void *);

	void			(*unregfunc)(void *);

	int			(*regfunc)(struct ftrace_event_call *);

	void			(*unregfunc)(struct ftrace_event_call *);

	int			id;

	int			(*raw_init)(void);

	int			(*show_format)(struct ftrace_event_call *call,

					       struct trace_seq *s);

	int			(*raw_init)(struct ftrace_event_call *);

	int			(*show_format)(struct ftrace_event_call *,

					       struct trace_seq *);

	int			(*define_fields)(struct ftrace_event_call *);

	struct list_head	fields;

	int			filter_active;
@@ -147,11 +147,12 @@ enum { 
	FILTER_PTR_STRING,

};



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);

extern int trace_define_common_fields(struct ftrace_event_call *call);

extern int trace_define_field(struct ftrace_event_call *call, char *type,

			      char *name, int offset, int size, int is_signed,

			      int filter_type);

extern int trace_add_event_call(struct ftrace_event_call *call);

extern void trace_remove_event_call(struct ftrace_event_call *call);



#define is_signed_type(type)	(((type)(-1)) < 0)

include/linux/syscalls.h

+2 −2
Original line number Diff line number Diff line
@@ -165,7 +165,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ 
	struct trace_event enter_syscall_print_##sname = {		\

		.trace                  = print_syscall_enter,		\

	};								\

	static int init_enter_##sname(void)				\

	static int init_enter_##sname(struct ftrace_event_call *call)	\

	{								\

		int num, id;						\

		num = syscall_name_to_nr("sys"#sname);			\
@@ -202,7 +202,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ 
	struct trace_event exit_syscall_print_##sname = {		\

		.trace                  = print_syscall_exit,		\

	};								\

	static int init_exit_##sname(void)				\

	static int init_exit_##sname(struct ftrace_event_call *call)	\

	{								\

		int num, id;						\

		num = syscall_name_to_nr("sys"#sname);			\

include/trace/ftrace.h

+8 −8
Original line number Diff line number Diff line
@@ -434,7 +434,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ 
 *	event_trace_printk(_RET_IP_, "<call>: " <fmt>);

 * }

 *

 * static int ftrace_reg_event_<call>(void)

 * static int ftrace_reg_event_<call>(struct ftrace_event_call *unused)

 * {

 *	int ret;

 *
@@ -445,7 +445,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ 
 *	return ret;

 * }

 *

 * static void ftrace_unreg_event_<call>(void)

 * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused)

 * {

 *	unregister_trace_<call>(ftrace_event_<call>);

 * }
@@ -478,7 +478,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ 
 *	trace_current_buffer_unlock_commit(event, irq_flags, pc);

 * }

 *

 * static int ftrace_raw_reg_event_<call>(void)

 * static int ftrace_raw_reg_event_<call>(struct ftrace_event_call *unused)

 * {

 *	int ret;

 *
@@ -489,7 +489,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ 
 *	return ret;

 * }

 *

 * static void ftrace_unreg_event_<call>(void)

 * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused)

 * {

 *	unregister_trace_<call>(ftrace_raw_event_<call>);

 * }
@@ -498,7 +498,7 @@ static void ftrace_profile_disable_##call(struct ftrace_event_call *event_call)\ 
 *	.trace			= ftrace_raw_output_<call>, <-- stage 2

 * };

 *

 * static int ftrace_raw_init_event_<call>(void)

 * static int ftrace_raw_init_event_<call>(struct ftrace_event_call *unused)

 * {

 *	int id;

 *
@@ -592,7 +592,7 @@ static void ftrace_raw_event_##call(proto) \ 
		trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \

}									\

									\

static int ftrace_raw_reg_event_##call(void *ptr)			\

static int ftrace_raw_reg_event_##call(struct ftrace_event_call *unused)\

{									\

	int ret;							\

									\
@@ -603,7 +603,7 @@ static int ftrace_raw_reg_event_##call(void *ptr) \ 
	return ret;							\

}									\

									\

static void ftrace_raw_unreg_event_##call(void *ptr)			\

static void ftrace_raw_unreg_event_##call(struct ftrace_event_call *unused)\

{									\

	unregister_trace_##call(ftrace_raw_event_##call);		\

}									\
@@ -612,7 +612,7 @@ static struct trace_event ftrace_event_type_##call = { \ 
	.trace			= ftrace_raw_output_##call,		\

};									\

									\

static int ftrace_raw_init_event_##call(void)				\

static int ftrace_raw_init_event_##call(struct ftrace_event_call *unused)\

{									\

	int id;								\

									\

include/trace/syscall.h

+7 −4
Original line number Diff line number Diff line
@@ -39,16 +39,19 @@ void set_syscall_enter_id(int num, int id); 
void set_syscall_exit_id(int num, int id);

extern struct trace_event event_syscall_enter;

extern struct trace_event event_syscall_exit;

extern int reg_event_syscall_enter(void *ptr);

extern void unreg_event_syscall_enter(void *ptr);

extern int reg_event_syscall_exit(void *ptr);

extern void unreg_event_syscall_exit(void *ptr);



extern int syscall_enter_format(struct ftrace_event_call *call,

				struct trace_seq *s);

extern int syscall_exit_format(struct ftrace_event_call *call,

				struct trace_seq *s);

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);

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);

#endif

kernel/trace/trace_events.c

+84 −37
Original line number Diff line number Diff line
@@ -27,8 +27,8 @@ DEFINE_MUTEX(event_mutex); 


LIST_HEAD(ftrace_events);



int trace_define_field(struct ftrace_event_call *call, const char *type,

		       const char *name, int offset, int size, int is_signed,

int trace_define_field(struct ftrace_event_call *call, char *type,

		       char *name, int offset, int size, int is_signed,

		       int filter_type)

{

	struct ftrace_event_field *field;
@@ -92,9 +92,7 @@ int trace_define_common_fields(struct ftrace_event_call *call) 
}

EXPORT_SYMBOL_GPL(trace_define_common_fields);



#ifdef CONFIG_MODULES



static void trace_destroy_fields(struct ftrace_event_call *call)

void trace_destroy_fields(struct ftrace_event_call *call)

{

	struct ftrace_event_field *field, *next;
@@ -106,8 +104,6 @@ static void trace_destroy_fields(struct ftrace_event_call *call) 
	}

}



#endif /* CONFIG_MODULES */



static void ftrace_event_enable_disable(struct ftrace_event_call *call,

					int enable)

{
@@ -116,14 +112,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call, 
		if (call->enabled) {

			call->enabled = 0;

			tracing_stop_cmdline_record();

			call->unregfunc(call->data);

			call->unregfunc(call);

		}

		break;

	case 1:

		if (!call->enabled) {

			call->enabled = 1;

			tracing_start_cmdline_record();

			call->regfunc(call->data);

			call->regfunc(call);

		}

		break;

	}
@@ -991,27 +987,43 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, 
	return 0;

}



#define for_each_event(event, start, end)			\

	for (event = start;					\

	     (unsigned long)event < (unsigned long)end;		\

	     event++)

static int __trace_add_event_call(struct ftrace_event_call *call)

{

	struct dentry *d_events;

	int ret;



#ifdef CONFIG_MODULES

	if (!call->name)

		return -EINVAL;



static LIST_HEAD(ftrace_module_file_list);

	if (call->raw_init) {

		ret = call->raw_init(call);

		if (ret < 0) {

			if (ret != -ENOSYS)

				pr_warning("Could not initialize trace "

				"events/%s\n", call->name);

			return ret;

		}

	}



/*

 * Modules must own their file_operations to keep up with

 * reference counting.

 */

struct ftrace_module_file_ops {

	struct list_head		list;

	struct module			*mod;

	struct file_operations		id;

	struct file_operations		enable;

	struct file_operations		format;

	struct file_operations		filter;

};

	d_events = event_trace_events_dir();

	if (!d_events)

		return -ENOENT;



	list_add(&call->list, &ftrace_events);

	return event_create_dir(call, d_events, &ftrace_event_id_fops,

				&ftrace_enable_fops, &ftrace_event_filter_fops,

				&ftrace_event_format_fops);

}



/* Add an additional event_call dynamically */

int trace_add_event_call(struct ftrace_event_call *call)

{

	int ret;

	mutex_lock(&event_mutex);

	ret = __trace_add_event_call(call);

	mutex_unlock(&event_mutex);

	return ret;

}



static void remove_subsystem_dir(const char *name)

{
@@ -1039,6 +1051,48 @@ static void remove_subsystem_dir(const char *name) 
	}

}



static void __trace_remove_event_call(struct ftrace_event_call *call)

{

	ftrace_event_enable_disable(call, 0);

	if (call->event)

		__unregister_ftrace_event(call->event);

	debugfs_remove_recursive(call->dir);

	list_del(&call->list);

	trace_destroy_fields(call);

	destroy_preds(call);

	remove_subsystem_dir(call->system);

}



/* Remove an event_call */

void trace_remove_event_call(struct ftrace_event_call *call)

{

	mutex_lock(&event_mutex);

	__trace_remove_event_call(call);

	mutex_unlock(&event_mutex);

}



#define for_each_event(event, start, end)			\

	for (event = start;					\

	     (unsigned long)event < (unsigned long)end;		\

	     event++)



#ifdef CONFIG_MODULES



static LIST_HEAD(ftrace_module_file_list);



/*

 * Modules must own their file_operations to keep up with

 * reference counting.

 */

struct ftrace_module_file_ops {

	struct list_head		list;

	struct module			*mod;

	struct file_operations		id;

	struct file_operations		enable;

	struct file_operations		format;

	struct file_operations		filter;

};



static struct ftrace_module_file_ops *

trace_create_file_ops(struct module *mod)

{
@@ -1096,7 +1150,7 @@ static void trace_module_add_events(struct module *mod) 
		if (!call->name)

			continue;

		if (call->raw_init) {

			ret = call->raw_init();

			ret = call->raw_init(call);

			if (ret < 0) {

				if (ret != -ENOSYS)

					pr_warning("Could not initialize trace "
@@ -1131,14 +1185,7 @@ static void trace_module_remove_events(struct module *mod) 
	list_for_each_entry_safe(call, p, &ftrace_events, list) {

		if (call->mod == mod) {

			found = true;

			ftrace_event_enable_disable(call, 0);

			if (call->event)

				__unregister_ftrace_event(call->event);

			debugfs_remove_recursive(call->dir);

			list_del(&call->list);

			trace_destroy_fields(call);

			destroy_preds(call);

			remove_subsystem_dir(call->system);

			__trace_remove_event_call(call);

		}

	}
@@ -1256,7 +1303,7 @@ static __init int event_trace_init(void) 
		if (!call->name)

			continue;

		if (call->raw_init) {

			ret = call->raw_init();

			ret = call->raw_init(call);

			if (ret < 0) {

				if (ret != -ENOSYS)

					pr_warning("Could not initialize trace "