[deliverable/linux.git] / include / linux / tracepoint.h

#ifndef _LINUX_TRACEPOINT_H
#define _LINUX_TRACEPOINT_H

/*
 * Kernel Tracepoint API.
 *
 * See Documentation/trace/tracepoints.txt.
 *
 * Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Heavily inspired from the Linux Kernel Markers.
 *
 * This file is released under the GPLv2.
 * See the file COPYING for more details.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/static_key.h>

struct module;
struct tracepoint;
struct notifier_block;

struct tracepoint_func {
	void *func;
	void *data;
};

struct tracepoint {
	const char *name;		/* Tracepoint name */
	struct static_key key;
	void (*regfunc)(void);
	void (*unregfunc)(void);
	struct tracepoint_func __rcu *funcs;
};

extern int
tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
extern int
tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
extern void
for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
		void *priv);

#ifdef CONFIG_MODULES
struct tp_module {
	struct list_head list;
	struct module *mod;
};

bool trace_module_has_bad_taint(struct module *mod);
extern int register_tracepoint_module_notifier(struct notifier_block *nb);
extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
#else
static inline bool trace_module_has_bad_taint(struct module *mod)
{
	return false;
}
static inline
int register_tracepoint_module_notifier(struct notifier_block *nb)
{
	return 0;
}
static inline
int unregister_tracepoint_module_notifier(struct notifier_block *nb)
{
	return 0;
}
#endif /* CONFIG_MODULES */

/*
 * tracepoint_synchronize_unregister must be called between the last tracepoint
 * probe unregistration and the end of module exit to make sure there is no
 * caller executing a probe when it is freed.
 */
static inline void tracepoint_synchronize_unregister(void)
{
	synchronize_sched();
}

#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
extern void syscall_regfunc(void);
extern void syscall_unregfunc(void);
#endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */

#define PARAMS(args...) args

#endif /* _LINUX_TRACEPOINT_H */

/*
 * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
 *  file ifdef protection.
 *  This is due to the way trace events work. If a file includes two
 *  trace event headers under one "CREATE_TRACE_POINTS" the first include
 *  will override the TRACE_EVENT and break the second include.
 */

#ifndef DECLARE_TRACE

#define TP_PROTO(args...)	args
#define TP_ARGS(args...)	args
#define TP_CONDITION(args...)	args

#ifdef CONFIG_TRACEPOINTS

/*
 * it_func[0] is never NULL because there is at least one element in the array
 * when the array itself is non NULL.
 *
 * Note, the proto and args passed in includes "__data" as the first parameter.
 * The reason for this is to handle the "void" prototype. If a tracepoint
 * has a "void" prototype, then it is invalid to declare a function
 * as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just
 * "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto".
 */
#define __DO_TRACE(tp, proto, args, cond, prercu, postrcu)		\
	do {								\
		struct tracepoint_func *it_func_ptr;			\
		void *it_func;						\
		void *__data;						\
									\
		if (!(cond))						\
			return;						\
		prercu;							\
		rcu_read_lock_sched_notrace();				\
		it_func_ptr = rcu_dereference_sched((tp)->funcs);	\
		if (it_func_ptr) {					\
			do {						\
				it_func = (it_func_ptr)->func;		\
				__data = (it_func_ptr)->data;		\
				((void(*)(proto))(it_func))(args);	\
			} while ((++it_func_ptr)->func);		\
		}							\
		rcu_read_unlock_sched_notrace();			\
		postrcu;						\
	} while (0)

#ifndef MODULE
#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)	\
	static inline void trace_##name##_rcuidle(proto)		\
	{								\
		if (static_key_false(&__tracepoint_##name.key))		\
			__DO_TRACE(&__tracepoint_##name,		\
				TP_PROTO(data_proto),			\
				TP_ARGS(data_args),			\
				TP_CONDITION(cond),			\
				rcu_irq_enter(),			\
				rcu_irq_exit());			\
	}
#else
#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)
#endif

/*
 * Make sure the alignment of the structure in the __tracepoints section will
 * not add unwanted padding between the beginning of the section and the
 * structure. Force alignment to the same alignment as the section start.
 */
#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
	extern struct tracepoint __tracepoint_##name;			\
	static inline void trace_##name(proto)				\
	{								\
		if (static_key_false(&__tracepoint_##name.key))		\
			__DO_TRACE(&__tracepoint_##name,		\
				TP_PROTO(data_proto),			\
				TP_ARGS(data_args),			\
				TP_CONDITION(cond),,);			\
	}								\
	__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args),		\
		PARAMS(cond), PARAMS(data_proto), PARAMS(data_args))	\
	static inline int						\
	register_trace_##name(void (*probe)(data_proto), void *data)	\
	{								\
		return tracepoint_probe_register(&__tracepoint_##name,	\
						(void *)probe, data);	\
	}								\
	static inline int						\
	unregister_trace_##name(void (*probe)(data_proto), void *data)	\
	{								\
		return tracepoint_probe_unregister(&__tracepoint_##name,\
						(void *)probe, data);	\
	}								\
	static inline void						\
	check_trace_callback_type_##name(void (*cb)(data_proto))	\
	{								\
	}

/*
 * We have no guarantee that gcc and the linker won't up-align the tracepoint
 * structures, so we create an array of pointers that will be used for iteration
 * on the tracepoints.
 */
#define DEFINE_TRACE_FN(name, reg, unreg)				 \
	static const char __tpstrtab_##name[]				 \
	__attribute__((section("__tracepoints_strings"))) = #name;	 \
	struct tracepoint __tracepoint_##name				 \
	__attribute__((section("__tracepoints"))) =			 \
		{ __tpstrtab_##name, STATIC_KEY_INIT_FALSE, reg, unreg, NULL };\
	static struct tracepoint * const __tracepoint_ptr_##name __used	 \
	__attribute__((section("__tracepoints_ptrs"))) =		 \
		&__tracepoint_##name;

#define DEFINE_TRACE(name)						\
	DEFINE_TRACE_FN(name, NULL, NULL);

#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)				\
	EXPORT_SYMBOL_GPL(__tracepoint_##name)
#define EXPORT_TRACEPOINT_SYMBOL(name)					\
	EXPORT_SYMBOL(__tracepoint_##name)

#else /* !CONFIG_TRACEPOINTS */
#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
	static inline void trace_##name(proto)				\
	{ }								\
	static inline void trace_##name##_rcuidle(proto)		\
	{ }								\
	static inline int						\
	register_trace_##name(void (*probe)(data_proto),		\
			      void *data)				\
	{								\
		return -ENOSYS;						\
	}								\
	static inline int						\
	unregister_trace_##name(void (*probe)(data_proto),		\
				void *data)				\
	{								\
		return -ENOSYS;						\
	}								\
	static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
	{								\
	}

#define DEFINE_TRACE_FN(name, reg, unreg)
#define DEFINE_TRACE(name)
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)

#endif /* CONFIG_TRACEPOINTS */

/*
 * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
 * (void). "void" is a special value in a function prototype and can
 * not be combined with other arguments. Since the DECLARE_TRACE()
 * macro adds a data element at the beginning of the prototype,
 * we need a way to differentiate "(void *data, proto)" from
 * "(void *data, void)". The second prototype is invalid.
 *
 * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
 * and "void *__data" as the callback prototype.
 *
 * DECLARE_TRACE() passes "proto" as the tracepoint protoype and
 * "void *__data, proto" as the callback prototype.
 */
#define DECLARE_TRACE_NOARGS(name)					\
		__DECLARE_TRACE(name, void, , 1, void *__data, __data)

#define DECLARE_TRACE(name, proto, args)				\
		__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), 1,	\
				PARAMS(void *__data, proto),		\
				PARAMS(__data, args))

#define DECLARE_TRACE_CONDITION(name, proto, args, cond)		\
	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \
			PARAMS(void *__data, proto),			\
			PARAMS(__data, args))

#define TRACE_EVENT_FLAGS(event, flag)

#define TRACE_EVENT_PERF_PERM(event, expr...)

#endif /* DECLARE_TRACE */

#ifndef TRACE_EVENT
/*
 * For use with the TRACE_EVENT macro:
 *
 * We define a tracepoint, its arguments, its printk format
 * and its 'fast binary record' layout.
 *
 * Firstly, name your tracepoint via TRACE_EVENT(name : the
 * 'subsystem_event' notation is fine.
 *
 * Think about this whole construct as the
 * 'trace_sched_switch() function' from now on.
 *
 *
 *  TRACE_EVENT(sched_switch,
 *
 *	*
 *	* A function has a regular function arguments
 *	* prototype, declare it via TP_PROTO():
 *	*
 *
 *	TP_PROTO(struct rq *rq, struct task_struct *prev,
 *		 struct task_struct *next),
 *
 *	*
 *	* Define the call signature of the 'function'.
 *	* (Design sidenote: we use this instead of a
 *	*  TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
 *	*
 *
 *	TP_ARGS(rq, prev, next),
 *
 *	*
 *	* Fast binary tracing: define the trace record via
 *	* TP_STRUCT__entry(). You can think about it like a
 *	* regular C structure local variable definition.
 *	*
 *	* This is how the trace record is structured and will
 *	* be saved into the ring buffer. These are the fields
 *	* that will be exposed to user-space in
 *	* /sys/kernel/debug/tracing/events/<*>/format.
 *	*
 *	* The declared 'local variable' is called '__entry'
 *	*
 *	* __field(pid_t, prev_prid) is equivalent to a standard declariton:
 *	*
 *	*	pid_t	prev_pid;
 *	*
 *	* __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
 *	*
 *	*	char	prev_comm[TASK_COMM_LEN];
 *	*
 *
 *	TP_STRUCT__entry(
 *		__array(	char,	prev_comm,	TASK_COMM_LEN	)
 *		__field(	pid_t,	prev_pid			)
 *		__field(	int,	prev_prio			)
 *		__array(	char,	next_comm,	TASK_COMM_LEN	)
 *		__field(	pid_t,	next_pid			)
 *		__field(	int,	next_prio			)
 *	),
 *
 *	*
 *	* Assign the entry into the trace record, by embedding
 *	* a full C statement block into TP_fast_assign(). You
 *	* can refer to the trace record as '__entry' -
 *	* otherwise you can put arbitrary C code in here.
 *	*
 *	* Note: this C code will execute every time a trace event
 *	* happens, on an active tracepoint.
 *	*
 *
 *	TP_fast_assign(
 *		memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
 *		__entry->prev_pid	= prev->pid;
 *		__entry->prev_prio	= prev->prio;
 *		memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
 *		__entry->next_pid	= next->pid;
 *		__entry->next_prio	= next->prio;
 *	),
 *
 *	*
 *	* Formatted output of a trace record via TP_printk().
 *	* This is how the tracepoint will appear under ftrace
 *	* plugins that make use of this tracepoint.
 *	*
 *	* (raw-binary tracing wont actually perform this step.)
 *	*
 *
 *	TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
 *		__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
 *		__entry->next_comm, __entry->next_pid, __entry->next_prio),
 *
 * );
 *
 * This macro construct is thus used for the regular printk format
 * tracing setup, it is used to construct a function pointer based
 * tracepoint callback (this is used by programmatic plugins and
 * can also by used by generic instrumentation like SystemTap), and
 * it is also used to expose a structured trace record in
 * /sys/kernel/debug/tracing/events/.
 *
 * A set of (un)registration functions can be passed to the variant
 * TRACE_EVENT_FN to perform any (un)registration work.
 */

#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
#define DEFINE_EVENT(template, name, proto, args)		\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define DEFINE_EVENT_CONDITION(template, name, proto,		\
			       args, cond)			\
	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
				PARAMS(args), PARAMS(cond))

#define TRACE_EVENT(name, proto, args, struct, assign, print)	\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define TRACE_EVENT_FN(name, proto, args, struct,		\
		assign, print, reg, unreg)			\
	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define TRACE_EVENT_CONDITION(name, proto, args, cond,		\
			      struct, assign, print)		\
	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
				PARAMS(args), PARAMS(cond))

#define TRACE_EVENT_FLAGS(event, flag)

#define TRACE_EVENT_PERF_PERM(event, expr...)

#endif /* ifdef TRACE_EVENT (see note above) */
Commit	Line	Data
97e1c18e MD	1	#ifndef _LINUX_TRACEPOINT_H
	2	#define _LINUX_TRACEPOINT_H
	3
	4	/*
	5	* Kernel Tracepoint API.
	6	*
8cd09a59	7	* See Documentation/trace/tracepoints.txt.
97e1c18e	8	*
de7b2973	9	* Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
97e1c18e MD	10	*
	11	* Heavily inspired from the Linux Kernel Markers.
	12	*
	13	* This file is released under the GPLv2.
	14	* See the file COPYING for more details.
	15	*/
	16
b70e4f05	17	#include <linux/errno.h>
97e1c18e MD	18	#include <linux/types.h>
97e1c18e MD	19	#include <linux/rcupdate.h>
c5905afb	20	#include <linux/static_key.h>
97e1c18e MD	21
	22	struct module;
	23	struct tracepoint;
de7b2973	24	struct notifier_block;
97e1c18e	25
38516ab5 SR	26	struct tracepoint_func {
	27	void *func;
	28	void *data;
	29	};
	30
97e1c18e MD	31	struct tracepoint {
97e1c18e MD	32	const char name; / Tracepoint name */
c5905afb	33	struct static_key key;
97419875 JS	34	void (*regfunc)(void);
97419875 JS	35	void (*unregfunc)(void);
bd1c8b22	36	struct tracepoint_func __rcu *funcs;
65498646	37	};
97e1c18e	38
38516ab5	39	extern int
de7b2973 MD	40	tracepoint_probe_register(struct tracepoint tp, void probe, void *data);
	41	extern int
	42	tracepoint_probe_unregister(struct tracepoint tp, void probe, void *data);
	43	extern void
	44	for_each_kernel_tracepoint(void (fct)(struct tracepoint tp, void *priv),
	45	void *priv);
2e26ca71	46
b75ef8b4 MD	47	#ifdef CONFIG_MODULES
	48	struct tp_module {
	49	struct list_head list;
eb7d035c	50	struct module *mod;
b75ef8b4	51	};
de7b2973	52
45ab2813	53	bool trace_module_has_bad_taint(struct module *mod);
de7b2973 MD	54	extern int register_tracepoint_module_notifier(struct notifier_block *nb);
de7b2973 MD	55	extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
45ab2813 SRRH	56	#else
	57	static inline bool trace_module_has_bad_taint(struct module *mod)
	58	{
	59	return false;
	60	}
de7b2973 MD	61	static inline
	62	int register_tracepoint_module_notifier(struct notifier_block *nb)
	63	{
	64	return 0;
	65	}
	66	static inline
	67	int unregister_tracepoint_module_notifier(struct notifier_block *nb)
	68	{
	69	return 0;
	70	}
b75ef8b4 MD	71	#endif /* CONFIG_MODULES */
b75ef8b4 MD	72
2e26ca71 SR	73	/*
	74	* tracepoint_synchronize_unregister must be called between the last tracepoint
	75	* probe unregistration and the end of module exit to make sure there is no
	76	* caller executing a probe when it is freed.
	77	*/
	78	static inline void tracepoint_synchronize_unregister(void)
	79	{
	80	synchronize_sched();
	81	}
	82
b725dfea MD	83	#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	84	extern void syscall_regfunc(void);
	85	extern void syscall_unregfunc(void);
	86	#endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
	87
2e26ca71 SR	88	#define PARAMS(args...) args
2e26ca71 SR	89
2e26ca71 SR	90	#endif /* _LINUX_TRACEPOINT_H */
	91
	92	/*
	93	* Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
	94	* file ifdef protection.
	95	* This is due to the way trace events work. If a file includes two
	96	* trace event headers under one "CREATE_TRACE_POINTS" the first include
	97	* will override the TRACE_EVENT and break the second include.
	98	*/
	99
ea20d929 SR	100	#ifndef DECLARE_TRACE
ea20d929 SR	101
2939b046	102	#define TP_PROTO(args...) args
8cd09a59	103	#define TP_ARGS(args...) args
287050d3	104	#define TP_CONDITION(args...) args
97e1c18e MD	105
	106	#ifdef CONFIG_TRACEPOINTS
	107
	108	/*
	109	* it_func[0] is never NULL because there is at least one element in the array
	110	* when the array itself is non NULL.
38516ab5 SR	111	*
	112	* Note, the proto and args passed in includes "__data" as the first parameter.
	113	* The reason for this is to handle the "void" prototype. If a tracepoint
	114	* has a "void" prototype, then it is invalid to declare a function
	115	* as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just
	116	* "void data", where as the DECLARE_TRACE() will pass in "void data, proto".
97e1c18e	117	*/
2fbb90db	118	#define __DO_TRACE(tp, proto, args, cond, prercu, postrcu) \
97e1c18e	119	do { \
38516ab5 SR	120	struct tracepoint_func *it_func_ptr; \
	121	void *it_func; \
	122	void *__data; \
97e1c18e	123	\
287050d3 SR	124	if (!(cond)) \
287050d3 SR	125	return; \
2fbb90db	126	prercu; \
da7b3eab	127	rcu_read_lock_sched_notrace(); \
38516ab5 SR	128	it_func_ptr = rcu_dereference_sched((tp)->funcs); \
38516ab5 SR	129	if (it_func_ptr) { \
97e1c18e	130	do { \
38516ab5 SR	131	it_func = (it_func_ptr)->func; \
	132	__data = (it_func_ptr)->data; \
	133	((void(*)(proto))(it_func))(args); \
	134	} while ((++it_func_ptr)->func); \
97e1c18e	135	} \
da7b3eab	136	rcu_read_unlock_sched_notrace(); \
2fbb90db	137	postrcu; \
97e1c18e MD	138	} while (0)
97e1c18e MD	139
7ece55a4 JT	140	#ifndef MODULE
	141	#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) \
	142	static inline void trace_##name##_rcuidle(proto) \
	143	{ \
	144	if (static_key_false(&__tracepoint_##name.key)) \
	145	__DO_TRACE(&__tracepoint_##name, \
	146	TP_PROTO(data_proto), \
	147	TP_ARGS(data_args), \
	148	TP_CONDITION(cond), \
d6284099 PM	149	rcu_irq_enter(), \
d6284099 PM	150	rcu_irq_exit()); \
7ece55a4 JT	151	}
	152	#else
	153	#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)
	154	#endif
	155
97e1c18e MD	156	/*
	157	* Make sure the alignment of the structure in the __tracepoints section will
	158	* not add unwanted padding between the beginning of the section and the
	159	* structure. Force alignment to the same alignment as the section start.
	160	*/
2fbb90db	161	#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
7e066fb8	162	extern struct tracepoint __tracepoint_##name; \
97e1c18e MD	163	static inline void trace_##name(proto) \
97e1c18e MD	164	{ \
c5905afb	165	if (static_key_false(&__tracepoint_##name.key)) \
97e1c18e	166	__DO_TRACE(&__tracepoint_##name, \
38516ab5	167	TP_PROTO(data_proto), \
287050d3	168	TP_ARGS(data_args), \
2fbb90db SR	169	TP_CONDITION(cond),,); \
2fbb90db SR	170	} \
7ece55a4 JT	171	__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \
7ece55a4 JT	172	PARAMS(cond), PARAMS(data_proto), PARAMS(data_args)) \
38516ab5 SR	173	static inline int \
38516ab5 SR	174	register_trace_##name(void (probe)(data_proto), void data) \
97e1c18e	175	{ \
de7b2973 MD	176	return tracepoint_probe_register(&__tracepoint_##name, \
de7b2973 MD	177	(void *)probe, data); \
97e1c18e	178	} \
38516ab5 SR	179	static inline int \
38516ab5 SR	180	unregister_trace_##name(void (probe)(data_proto), void data) \
97e1c18e	181	{ \
de7b2973 MD	182	return tracepoint_probe_unregister(&__tracepoint_##name,\
de7b2973 MD	183	(void *)probe, data); \
53da59aa	184	} \
38516ab5 SR	185	static inline void \
38516ab5 SR	186	check_trace_callback_type_##name(void (*cb)(data_proto)) \
53da59aa	187	{ \
97e1c18e MD	188	}
97e1c18e MD	189
65498646 MD	190	/*
	191	* We have no guarantee that gcc and the linker won't up-align the tracepoint
	192	* structures, so we create an array of pointers that will be used for iteration
	193	* on the tracepoints.
	194	*/
d430d3d7 JB	195	#define DEFINE_TRACE_FN(name, reg, unreg) \
	196	static const char __tpstrtab_##name[] \
	197	__attribute__((section("__tracepoints_strings"))) = #name; \
	198	struct tracepoint __tracepoint_##name \
	199	__attribute__((section("__tracepoints"))) = \
c5905afb	200	{ __tpstrtab_##name, STATIC_KEY_INIT_FALSE, reg, unreg, NULL };\
d430d3d7 JB	201	static struct tracepoint * const __tracepoint_ptr_##name __used \
d430d3d7 JB	202	__attribute__((section("__tracepoints_ptrs"))) = \
65498646	203	&__tracepoint_##name;
97419875 JS	204
	205	#define DEFINE_TRACE(name) \
	206	DEFINE_TRACE_FN(name, NULL, NULL);
7e066fb8 MD	207
	208	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
	209	EXPORT_SYMBOL_GPL(__tracepoint_##name)
	210	#define EXPORT_TRACEPOINT_SYMBOL(name) \
	211	EXPORT_SYMBOL(__tracepoint_##name)
	212
97e1c18e	213	#else /* !CONFIG_TRACEPOINTS */
2fbb90db	214	#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
97e1c18e MD	215	static inline void trace_##name(proto) \
97e1c18e MD	216	{ } \
2fbb90db SR	217	static inline void trace_##name##_rcuidle(proto) \
2fbb90db SR	218	{ } \
38516ab5 SR	219	static inline int \
	220	register_trace_##name(void (*probe)(data_proto), \
	221	void *data) \
97e1c18e MD	222	{ \
	223	return -ENOSYS; \
	224	} \
38516ab5 SR	225	static inline int \
	226	unregister_trace_##name(void (*probe)(data_proto), \
	227	void *data) \
c420970e MD	228	{ \
c420970e MD	229	return -ENOSYS; \
53da59aa	230	} \
38516ab5	231	static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
53da59aa	232	{ \
c420970e	233	}
97e1c18e	234
97419875	235	#define DEFINE_TRACE_FN(name, reg, unreg)
7e066fb8 MD	236	#define DEFINE_TRACE(name)
	237	#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
	238	#define EXPORT_TRACEPOINT_SYMBOL(name)
	239
97e1c18e	240	#endif /* CONFIG_TRACEPOINTS */
38516ab5 SR	241
	242	/*
	243	* The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
	244	* (void). "void" is a special value in a function prototype and can
	245	* not be combined with other arguments. Since the DECLARE_TRACE()
	246	* macro adds a data element at the beginning of the prototype,
	247	* we need a way to differentiate "(void *data, proto)" from
	248	* "(void *data, void)". The second prototype is invalid.
	249	*
	250	* DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
	251	* and "void *__data" as the callback prototype.
	252	*
	253	* DECLARE_TRACE() passes "proto" as the tracepoint protoype and
	254	* "void *__data, proto" as the callback prototype.
	255	*/
	256	#define DECLARE_TRACE_NOARGS(name) \
287050d3	257	__DECLARE_TRACE(name, void, , 1, void *__data, __data)
38516ab5 SR	258
38516ab5 SR	259	#define DECLARE_TRACE(name, proto, args) \
287050d3	260	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), 1, \
38516ab5 SR	261	PARAMS(void *__data, proto), \
	262	PARAMS(__data, args))
	263
287050d3 SR	264	#define DECLARE_TRACE_CONDITION(name, proto, args, cond) \
	265	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \
	266	PARAMS(void *__data, proto), \
	267	PARAMS(__data, args))
	268
1ed0c597 FW	269	#define TRACE_EVENT_FLAGS(event, flag)
1ed0c597 FW	270
d5b5f391 PZ	271	#define TRACE_EVENT_PERF_PERM(event, expr...)
d5b5f391 PZ	272
ea20d929	273	#endif /* DECLARE_TRACE */
97e1c18e	274
ea20d929	275	#ifndef TRACE_EVENT
823f9124 SR	276	/*
	277	* For use with the TRACE_EVENT macro:
	278	*
	279	* We define a tracepoint, its arguments, its printk format
2621bca8	280	* and its 'fast binary record' layout.
823f9124 SR	281	*
	282	* Firstly, name your tracepoint via TRACE_EVENT(name : the
	283	* 'subsystem_event' notation is fine.
	284	*
	285	* Think about this whole construct as the
	286	* 'trace_sched_switch() function' from now on.
	287	*
	288	*
	289	* TRACE_EVENT(sched_switch,
	290	*
	291	* *
	292	* * A function has a regular function arguments
	293	* * prototype, declare it via TP_PROTO():
	294	* *
	295	*
ef18012b SR	296	* TP_PROTO(struct rq rq, struct task_struct prev,
ef18012b SR	297	* struct task_struct *next),
823f9124 SR	298	*
	299	* *
	300	* * Define the call signature of the 'function'.
	301	* * (Design sidenote: we use this instead of a
	302	* * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
	303	* *
	304	*
ef18012b	305	* TP_ARGS(rq, prev, next),
823f9124 SR	306	*
	307	* *
	308	* * Fast binary tracing: define the trace record via
	309	* * TP_STRUCT__entry(). You can think about it like a
	310	* * regular C structure local variable definition.
	311	* *
	312	* * This is how the trace record is structured and will
	313	* * be saved into the ring buffer. These are the fields
	314	* * that will be exposed to user-space in
156f5a78	315	* * /sys/kernel/debug/tracing/events/<*>/format.
823f9124 SR	316	* *
	317	* * The declared 'local variable' is called '__entry'
	318	* *
	319	* * __field(pid_t, prev_prid) is equivalent to a standard declariton:
	320	* *
	321	* * pid_t prev_pid;
	322	* *
	323	* * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
	324	* *
	325	* * char prev_comm[TASK_COMM_LEN];
	326	* *
	327	*
	328	* TP_STRUCT__entry(
	329	* __array( char, prev_comm, TASK_COMM_LEN )
	330	* __field( pid_t, prev_pid )
	331	* __field( int, prev_prio )
	332	* __array( char, next_comm, TASK_COMM_LEN )
	333	* __field( pid_t, next_pid )
	334	* __field( int, next_prio )
	335	* ),
	336	*
	337	* *
	338	* * Assign the entry into the trace record, by embedding
	339	* * a full C statement block into TP_fast_assign(). You
	340	* * can refer to the trace record as '__entry' -
	341	* * otherwise you can put arbitrary C code in here.
	342	* *
	343	* * Note: this C code will execute every time a trace event
	344	* * happens, on an active tracepoint.
	345	* *
	346	*
ef18012b SR	347	* TP_fast_assign(
	348	* memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
	349	* __entry->prev_pid = prev->pid;
	350	* __entry->prev_prio = prev->prio;
823f9124 SR	351	* memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
823f9124 SR	352	* __entry->next_pid = next->pid;
ef18012b	353	* __entry->next_prio = next->prio;
ec6e7c3a	354	* ),
823f9124 SR	355	*
	356	* *
	357	* * Formatted output of a trace record via TP_printk().
	358	* * This is how the tracepoint will appear under ftrace
	359	* * plugins that make use of this tracepoint.
	360	* *
	361	* * (raw-binary tracing wont actually perform this step.)
	362	* *
	363	*
	364	* TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
	365	* __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
	366	* __entry->next_comm, __entry->next_pid, __entry->next_prio),
	367	*
	368	* );
	369	*
	370	* This macro construct is thus used for the regular printk format
	371	* tracing setup, it is used to construct a function pointer based
	372	* tracepoint callback (this is used by programmatic plugins and
	373	* can also by used by generic instrumentation like SystemTap), and
	374	* it is also used to expose a structured trace record in
156f5a78	375	* /sys/kernel/debug/tracing/events/.
97419875 JS	376	*
	377	* A set of (un)registration functions can be passed to the variant
	378	* TRACE_EVENT_FN to perform any (un)registration work.
823f9124 SR	379	*/
823f9124 SR	380
091ad365	381	#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
ff038f5c SR	382	#define DEFINE_EVENT(template, name, proto, args) \
ff038f5c SR	383	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
f5abaa1b SR	384	#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
f5abaa1b SR	385	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
e5bc9721 SR	386	#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
e5bc9721 SR	387	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
287050d3 SR	388	#define DEFINE_EVENT_CONDITION(template, name, proto, \
	389	args, cond) \
	390	DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
	391	PARAMS(args), PARAMS(cond))
ff038f5c	392
30a8fecc	393	#define TRACE_EVENT(name, proto, args, struct, assign, print) \
da4d0302	394	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
97419875 JS	395	#define TRACE_EVENT_FN(name, proto, args, struct, \
	396	assign, print, reg, unreg) \
	397	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
287050d3 SR	398	#define TRACE_EVENT_CONDITION(name, proto, args, cond, \
	399	struct, assign, print) \
	400	DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
	401	PARAMS(args), PARAMS(cond))
7cb2e3ee	402
1ed0c597 FW	403	#define TRACE_EVENT_FLAGS(event, flag)
1ed0c597 FW	404
d5b5f391 PZ	405	#define TRACE_EVENT_PERF_PERM(event, expr...)
d5b5f391 PZ	406
7cb2e3ee	407	#endif /* ifdef TRACE_EVENT (see note above) */