xref: /linux-6.15/include/linux/tracepoint.h (revision 2fb7eb3d)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef _LINUX_TRACEPOINT_H
3 #define _LINUX_TRACEPOINT_H
4 
5 /*
6  * Kernel Tracepoint API.
7  *
8  * See Documentation/trace/tracepoints.rst.
9  *
10  * Copyright (C) 2008-2014 Mathieu Desnoyers <[email protected]>
11  *
12  * Heavily inspired from the Linux Kernel Markers.
13  */
14 
15 #include <linux/smp.h>
16 #include <linux/srcu.h>
17 #include <linux/errno.h>
18 #include <linux/types.h>
19 #include <linux/rcupdate.h>
20 #include <linux/rcupdate_trace.h>
21 #include <linux/tracepoint-defs.h>
22 #include <linux/static_call.h>
23 
24 struct module;
25 struct tracepoint;
26 struct notifier_block;
27 
28 struct trace_eval_map {
29 	const char		*system;
30 	const char		*eval_string;
31 	unsigned long		eval_value;
32 };
33 
34 #define TRACEPOINT_DEFAULT_PRIO	10
35 
36 extern int
37 tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
38 extern int
39 tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data,
40 			       int prio);
41 extern int
42 tracepoint_probe_register_prio_may_exist(struct tracepoint *tp, void *probe, void *data,
43 					 int prio);
44 extern int
45 tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
46 static inline int
47 tracepoint_probe_register_may_exist(struct tracepoint *tp, void *probe,
48 				    void *data)
49 {
50 	return tracepoint_probe_register_prio_may_exist(tp, probe, data,
51 							TRACEPOINT_DEFAULT_PRIO);
52 }
53 extern void
54 for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
55 		void *priv);
56 
57 #ifdef CONFIG_MODULES
58 struct tp_module {
59 	struct list_head list;
60 	struct module *mod;
61 };
62 
63 bool trace_module_has_bad_taint(struct module *mod);
64 extern int register_tracepoint_module_notifier(struct notifier_block *nb);
65 extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
66 void for_each_module_tracepoint(void (*fct)(struct tracepoint *,
67 					struct module *, void *),
68 				void *priv);
69 void for_each_tracepoint_in_module(struct module *,
70 				   void (*fct)(struct tracepoint *,
71 					struct module *, void *),
72 				   void *priv);
73 #else
74 static inline bool trace_module_has_bad_taint(struct module *mod)
75 {
76 	return false;
77 }
78 static inline
79 int register_tracepoint_module_notifier(struct notifier_block *nb)
80 {
81 	return 0;
82 }
83 static inline
84 int unregister_tracepoint_module_notifier(struct notifier_block *nb)
85 {
86 	return 0;
87 }
88 static inline
89 void for_each_module_tracepoint(void (*fct)(struct tracepoint *,
90 					struct module *, void *),
91 				void *priv)
92 {
93 }
94 static inline
95 void for_each_tracepoint_in_module(struct module *mod,
96 				   void (*fct)(struct tracepoint *,
97 					struct module *, void *),
98 				   void *priv)
99 {
100 }
101 #endif /* CONFIG_MODULES */
102 
103 /*
104  * tracepoint_synchronize_unregister must be called between the last tracepoint
105  * probe unregistration and the end of module exit to make sure there is no
106  * caller executing a probe when it is freed.
107  *
108  * An alternative is to use the following for batch reclaim associated
109  * with a given tracepoint:
110  *
111  * - tracepoint_is_faultable() == false: call_rcu()
112  * - tracepoint_is_faultable() == true:  call_rcu_tasks_trace()
113  */
114 #ifdef CONFIG_TRACEPOINTS
115 static inline void tracepoint_synchronize_unregister(void)
116 {
117 	synchronize_rcu_tasks_trace();
118 	synchronize_rcu();
119 }
120 static inline bool tracepoint_is_faultable(struct tracepoint *tp)
121 {
122 	return tp->ext && tp->ext->faultable;
123 }
124 #else
125 static inline void tracepoint_synchronize_unregister(void)
126 { }
127 static inline bool tracepoint_is_faultable(struct tracepoint *tp)
128 {
129 	return false;
130 }
131 #endif
132 
133 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
134 extern int syscall_regfunc(void);
135 extern void syscall_unregfunc(void);
136 #endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
137 
138 #ifndef PARAMS
139 #define PARAMS(args...) args
140 #endif
141 
142 #define TRACE_DEFINE_ENUM(x)
143 #define TRACE_DEFINE_SIZEOF(x)
144 
145 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
146 static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
147 {
148 	return offset_to_ptr(p);
149 }
150 
151 #define __TRACEPOINT_ENTRY(name)					\
152 	asm("	.section \"__tracepoints_ptrs\", \"a\"		\n"	\
153 	    "	.balign 4					\n"	\
154 	    "	.long 	__tracepoint_" #name " - .		\n"	\
155 	    "	.previous					\n")
156 #else
157 static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
158 {
159 	return *p;
160 }
161 
162 #define __TRACEPOINT_ENTRY(name)					 \
163 	static tracepoint_ptr_t __tracepoint_ptr_##name __used		 \
164 	__section("__tracepoints_ptrs") = &__tracepoint_##name
165 #endif
166 
167 #endif /* _LINUX_TRACEPOINT_H */
168 
169 /*
170  * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
171  *  file ifdef protection.
172  *  This is due to the way trace events work. If a file includes two
173  *  trace event headers under one "CREATE_TRACE_POINTS" the first include
174  *  will override the TRACE_EVENT and break the second include.
175  */
176 
177 #ifndef DECLARE_TRACE
178 
179 #define TP_PROTO(args...)	args
180 #define TP_ARGS(args...)	args
181 #define TP_CONDITION(args...)	args
182 
183 /*
184  * Individual subsystem my have a separate configuration to
185  * enable their tracepoints. By default, this file will create
186  * the tracepoints if CONFIG_TRACEPOINTS is defined. If a subsystem
187  * wants to be able to disable its tracepoints from being created
188  * it can define NOTRACE before including the tracepoint headers.
189  */
190 #if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE)
191 #define TRACEPOINTS_ENABLED
192 #endif
193 
194 #ifdef TRACEPOINTS_ENABLED
195 
196 #ifdef CONFIG_HAVE_STATIC_CALL
197 #define __DO_TRACE_CALL(name, args)					\
198 	do {								\
199 		struct tracepoint_func *it_func_ptr;			\
200 		void *__data;						\
201 		it_func_ptr =						\
202 			rcu_dereference_raw((&__tracepoint_##name)->funcs); \
203 		if (it_func_ptr) {					\
204 			__data = (it_func_ptr)->data;			\
205 			static_call(tp_func_##name)(__data, args);	\
206 		}							\
207 	} while (0)
208 #else
209 #define __DO_TRACE_CALL(name, args)	__traceiter_##name(NULL, args)
210 #endif /* CONFIG_HAVE_STATIC_CALL */
211 
212 /*
213  * it_func[0] is never NULL because there is at least one element in the array
214  * when the array itself is non NULL.
215  *
216  * With @syscall=0, the tracepoint callback array dereference is
217  * protected by disabling preemption.
218  * With @syscall=1, the tracepoint callback array dereference is
219  * protected by Tasks Trace RCU, which allows probes to handle page
220  * faults.
221  */
222 #define __DO_TRACE(name, args, cond, syscall)				\
223 	do {								\
224 		int __maybe_unused __idx = 0;				\
225 									\
226 		if (!(cond))						\
227 			return;						\
228 									\
229 		if (syscall)						\
230 			rcu_read_lock_trace();				\
231 		else							\
232 			preempt_disable_notrace();			\
233 									\
234 		__DO_TRACE_CALL(name, TP_ARGS(args));			\
235 									\
236 		if (syscall)						\
237 			rcu_read_unlock_trace();			\
238 		else							\
239 			preempt_enable_notrace();			\
240 	} while (0)
241 
242 /*
243  * Make sure the alignment of the structure in the __tracepoints section will
244  * not add unwanted padding between the beginning of the section and the
245  * structure. Force alignment to the same alignment as the section start.
246  *
247  * When lockdep is enabled, we make sure to always test if RCU is
248  * "watching" regardless if the tracepoint is enabled or not. Tracepoints
249  * require RCU to be active, and it should always warn at the tracepoint
250  * site if it is not watching, as it will need to be active when the
251  * tracepoint is enabled.
252  */
253 #define __DECLARE_TRACE_COMMON(name, proto, args, cond, data_proto)	\
254 	extern int __traceiter_##name(data_proto);			\
255 	DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name);	\
256 	extern struct tracepoint __tracepoint_##name;			\
257 	static inline int						\
258 	register_trace_##name(void (*probe)(data_proto), void *data)	\
259 	{								\
260 		return tracepoint_probe_register(&__tracepoint_##name,	\
261 						(void *)probe, data);	\
262 	}								\
263 	static inline int						\
264 	register_trace_prio_##name(void (*probe)(data_proto), void *data,\
265 				   int prio)				\
266 	{								\
267 		return tracepoint_probe_register_prio(&__tracepoint_##name, \
268 					      (void *)probe, data, prio); \
269 	}								\
270 	static inline int						\
271 	unregister_trace_##name(void (*probe)(data_proto), void *data)	\
272 	{								\
273 		return tracepoint_probe_unregister(&__tracepoint_##name,\
274 						(void *)probe, data);	\
275 	}								\
276 	static inline void						\
277 	check_trace_callback_type_##name(void (*cb)(data_proto))	\
278 	{								\
279 	}								\
280 	static inline bool						\
281 	trace_##name##_enabled(void)					\
282 	{								\
283 		return static_branch_unlikely(&__tracepoint_##name.key);\
284 	}
285 
286 #define __DECLARE_TRACE(name, proto, args, cond, data_proto)		\
287 	__DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
288 	static inline void trace_##name(proto)				\
289 	{								\
290 		if (static_branch_unlikely(&__tracepoint_##name.key))	\
291 			__DO_TRACE(name,				\
292 				TP_ARGS(args),				\
293 				TP_CONDITION(cond), 0);			\
294 		if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {		\
295 			WARN_ONCE(!rcu_is_watching(),			\
296 				  "RCU not watching for tracepoint");	\
297 		}							\
298 	}
299 
300 #define __DECLARE_TRACE_SYSCALL(name, proto, args, cond, data_proto)	\
301 	__DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
302 	static inline void trace_##name(proto)				\
303 	{								\
304 		might_fault();						\
305 		if (static_branch_unlikely(&__tracepoint_##name.key))	\
306 			__DO_TRACE(name,				\
307 				TP_ARGS(args),				\
308 				TP_CONDITION(cond), 1);			\
309 		if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {		\
310 			WARN_ONCE(!rcu_is_watching(),			\
311 				  "RCU not watching for tracepoint");	\
312 		}							\
313 	}
314 
315 /*
316  * We have no guarantee that gcc and the linker won't up-align the tracepoint
317  * structures, so we create an array of pointers that will be used for iteration
318  * on the tracepoints.
319  */
320 #define __DEFINE_TRACE_EXT(_name, _ext, proto, args)			\
321 	static const char __tpstrtab_##_name[]				\
322 	__section("__tracepoints_strings") = #_name;			\
323 	extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name);	\
324 	int __traceiter_##_name(void *__data, proto);			\
325 	void __probestub_##_name(void *__data, proto);			\
326 	struct tracepoint __tracepoint_##_name	__used			\
327 	__section("__tracepoints") = {					\
328 		.name = __tpstrtab_##_name,				\
329 		.key = STATIC_KEY_FALSE_INIT,				\
330 		.static_call_key = &STATIC_CALL_KEY(tp_func_##_name),	\
331 		.static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
332 		.iterator = &__traceiter_##_name,			\
333 		.probestub = &__probestub_##_name,			\
334 		.funcs = NULL,						\
335 		.ext = _ext,						\
336 	};								\
337 	__TRACEPOINT_ENTRY(_name);					\
338 	int __traceiter_##_name(void *__data, proto)			\
339 	{								\
340 		struct tracepoint_func *it_func_ptr;			\
341 		void *it_func;						\
342 									\
343 		it_func_ptr =						\
344 			rcu_dereference_raw((&__tracepoint_##_name)->funcs); \
345 		if (it_func_ptr) {					\
346 			do {						\
347 				it_func = READ_ONCE((it_func_ptr)->func); \
348 				__data = (it_func_ptr)->data;		\
349 				((void(*)(void *, proto))(it_func))(__data, args); \
350 			} while ((++it_func_ptr)->func);		\
351 		}							\
352 		return 0;						\
353 	}								\
354 	void __probestub_##_name(void *__data, proto)			\
355 	{								\
356 	}								\
357 	DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
358 
359 #define DEFINE_TRACE_FN(_name, _reg, _unreg, _proto, _args)		\
360 	static struct tracepoint_ext __tracepoint_ext_##_name = {	\
361 		.regfunc = _reg,					\
362 		.unregfunc = _unreg,					\
363 		.faultable = false,					\
364 	};								\
365 	__DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args));
366 
367 #define DEFINE_TRACE_SYSCALL(_name, _reg, _unreg, _proto, _args)	\
368 	static struct tracepoint_ext __tracepoint_ext_##_name = {	\
369 		.regfunc = _reg,					\
370 		.unregfunc = _unreg,					\
371 		.faultable = true,					\
372 	};								\
373 	__DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args));
374 
375 #define DEFINE_TRACE(_name, _proto, _args)				\
376 	__DEFINE_TRACE_EXT(_name, NULL, PARAMS(_proto), PARAMS(_args));
377 
378 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)				\
379 	EXPORT_SYMBOL_GPL(__tracepoint_##name);				\
380 	EXPORT_SYMBOL_GPL(__traceiter_##name);				\
381 	EXPORT_STATIC_CALL_GPL(tp_func_##name)
382 #define EXPORT_TRACEPOINT_SYMBOL(name)					\
383 	EXPORT_SYMBOL(__tracepoint_##name);				\
384 	EXPORT_SYMBOL(__traceiter_##name);				\
385 	EXPORT_STATIC_CALL(tp_func_##name)
386 
387 
388 #else /* !TRACEPOINTS_ENABLED */
389 #define __DECLARE_TRACE(name, proto, args, cond, data_proto)		\
390 	static inline void trace_##name(proto)				\
391 	{ }								\
392 	static inline int						\
393 	register_trace_##name(void (*probe)(data_proto),		\
394 			      void *data)				\
395 	{								\
396 		return -ENOSYS;						\
397 	}								\
398 	static inline int						\
399 	unregister_trace_##name(void (*probe)(data_proto),		\
400 				void *data)				\
401 	{								\
402 		return -ENOSYS;						\
403 	}								\
404 	static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
405 	{								\
406 	}								\
407 	static inline bool						\
408 	trace_##name##_enabled(void)					\
409 	{								\
410 		return false;						\
411 	}
412 
413 #define __DECLARE_TRACE_SYSCALL	__DECLARE_TRACE
414 
415 #define DEFINE_TRACE_FN(name, reg, unreg, proto, args)
416 #define DEFINE_TRACE_SYSCALL(name, reg, unreg, proto, args)
417 #define DEFINE_TRACE(name, proto, args)
418 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
419 #define EXPORT_TRACEPOINT_SYMBOL(name)
420 
421 #endif /* TRACEPOINTS_ENABLED */
422 
423 #ifdef CONFIG_TRACING
424 /**
425  * tracepoint_string - register constant persistent string to trace system
426  * @str - a constant persistent string that will be referenced in tracepoints
427  *
428  * If constant strings are being used in tracepoints, it is faster and
429  * more efficient to just save the pointer to the string and reference
430  * that with a printf "%s" instead of saving the string in the ring buffer
431  * and wasting space and time.
432  *
433  * The problem with the above approach is that userspace tools that read
434  * the binary output of the trace buffers do not have access to the string.
435  * Instead they just show the address of the string which is not very
436  * useful to users.
437  *
438  * With tracepoint_string(), the string will be registered to the tracing
439  * system and exported to userspace via the debugfs/tracing/printk_formats
440  * file that maps the string address to the string text. This way userspace
441  * tools that read the binary buffers have a way to map the pointers to
442  * the ASCII strings they represent.
443  *
444  * The @str used must be a constant string and persistent as it would not
445  * make sense to show a string that no longer exists. But it is still fine
446  * to be used with modules, because when modules are unloaded, if they
447  * had tracepoints, the ring buffers are cleared too. As long as the string
448  * does not change during the life of the module, it is fine to use
449  * tracepoint_string() within a module.
450  */
451 #define tracepoint_string(str)						\
452 	({								\
453 		static const char *___tp_str __tracepoint_string = str; \
454 		___tp_str;						\
455 	})
456 #define __tracepoint_string	__used __section("__tracepoint_str")
457 #else
458 /*
459  * tracepoint_string() is used to save the string address for userspace
460  * tracing tools. When tracing isn't configured, there's no need to save
461  * anything.
462  */
463 # define tracepoint_string(str) str
464 # define __tracepoint_string
465 #endif
466 
467 #define DECLARE_TRACE(name, proto, args)				\
468 	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),		\
469 			cpu_online(raw_smp_processor_id()),		\
470 			PARAMS(void *__data, proto))
471 
472 #define DECLARE_TRACE_CONDITION(name, proto, args, cond)		\
473 	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),		\
474 			cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \
475 			PARAMS(void *__data, proto))
476 
477 #define DECLARE_TRACE_SYSCALL(name, proto, args)			\
478 	__DECLARE_TRACE_SYSCALL(name, PARAMS(proto), PARAMS(args),	\
479 				cpu_online(raw_smp_processor_id()),	\
480 				PARAMS(void *__data, proto))
481 
482 #define TRACE_EVENT_FLAGS(event, flag)
483 
484 #define TRACE_EVENT_PERF_PERM(event, expr...)
485 
486 #endif /* DECLARE_TRACE */
487 
488 #ifndef TRACE_EVENT
489 /*
490  * For use with the TRACE_EVENT macro:
491  *
492  * We define a tracepoint, its arguments, its printk format
493  * and its 'fast binary record' layout.
494  *
495  * Firstly, name your tracepoint via TRACE_EVENT(name : the
496  * 'subsystem_event' notation is fine.
497  *
498  * Think about this whole construct as the
499  * 'trace_sched_switch() function' from now on.
500  *
501  *
502  *  TRACE_EVENT(sched_switch,
503  *
504  *	*
505  *	* A function has a regular function arguments
506  *	* prototype, declare it via TP_PROTO():
507  *	*
508  *
509  *	TP_PROTO(struct rq *rq, struct task_struct *prev,
510  *		 struct task_struct *next),
511  *
512  *	*
513  *	* Define the call signature of the 'function'.
514  *	* (Design sidenote: we use this instead of a
515  *	*  TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
516  *	*
517  *
518  *	TP_ARGS(rq, prev, next),
519  *
520  *	*
521  *	* Fast binary tracing: define the trace record via
522  *	* TP_STRUCT__entry(). You can think about it like a
523  *	* regular C structure local variable definition.
524  *	*
525  *	* This is how the trace record is structured and will
526  *	* be saved into the ring buffer. These are the fields
527  *	* that will be exposed to user-space in
528  *	* /sys/kernel/tracing/events/<*>/format.
529  *	*
530  *	* The declared 'local variable' is called '__entry'
531  *	*
532  *	* __field(pid_t, prev_pid) is equivalent to a standard declaration:
533  *	*
534  *	*	pid_t	prev_pid;
535  *	*
536  *	* __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
537  *	*
538  *	*	char	prev_comm[TASK_COMM_LEN];
539  *	*
540  *
541  *	TP_STRUCT__entry(
542  *		__array(	char,	prev_comm,	TASK_COMM_LEN	)
543  *		__field(	pid_t,	prev_pid			)
544  *		__field(	int,	prev_prio			)
545  *		__array(	char,	next_comm,	TASK_COMM_LEN	)
546  *		__field(	pid_t,	next_pid			)
547  *		__field(	int,	next_prio			)
548  *	),
549  *
550  *	*
551  *	* Assign the entry into the trace record, by embedding
552  *	* a full C statement block into TP_fast_assign(). You
553  *	* can refer to the trace record as '__entry' -
554  *	* otherwise you can put arbitrary C code in here.
555  *	*
556  *	* Note: this C code will execute every time a trace event
557  *	* happens, on an active tracepoint.
558  *	*
559  *
560  *	TP_fast_assign(
561  *		memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
562  *		__entry->prev_pid	= prev->pid;
563  *		__entry->prev_prio	= prev->prio;
564  *		memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
565  *		__entry->next_pid	= next->pid;
566  *		__entry->next_prio	= next->prio;
567  *	),
568  *
569  *	*
570  *	* Formatted output of a trace record via TP_printk().
571  *	* This is how the tracepoint will appear under ftrace
572  *	* plugins that make use of this tracepoint.
573  *	*
574  *	* (raw-binary tracing wont actually perform this step.)
575  *	*
576  *
577  *	TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
578  *		__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
579  *		__entry->next_comm, __entry->next_pid, __entry->next_prio),
580  *
581  * );
582  *
583  * This macro construct is thus used for the regular printk format
584  * tracing setup, it is used to construct a function pointer based
585  * tracepoint callback (this is used by programmatic plugins and
586  * can also by used by generic instrumentation like SystemTap), and
587  * it is also used to expose a structured trace record in
588  * /sys/kernel/tracing/events/.
589  *
590  * A set of (un)registration functions can be passed to the variant
591  * TRACE_EVENT_FN to perform any (un)registration work.
592  */
593 
594 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
595 #define DEFINE_EVENT(template, name, proto, args)		\
596 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
597 #define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
598 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
599 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
600 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
601 #define DEFINE_EVENT_CONDITION(template, name, proto,		\
602 			       args, cond)			\
603 	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
604 				PARAMS(args), PARAMS(cond))
605 
606 #define TRACE_EVENT(name, proto, args, struct, assign, print)	\
607 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
608 #define TRACE_EVENT_FN(name, proto, args, struct,		\
609 		assign, print, reg, unreg)			\
610 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
611 #define TRACE_EVENT_FN_COND(name, proto, args, cond, struct,		\
612 		assign, print, reg, unreg)			\
613 	DECLARE_TRACE_CONDITION(name, PARAMS(proto),	\
614 			PARAMS(args), PARAMS(cond))
615 #define TRACE_EVENT_CONDITION(name, proto, args, cond,		\
616 			      struct, assign, print)		\
617 	DECLARE_TRACE_CONDITION(name, PARAMS(proto),		\
618 				PARAMS(args), PARAMS(cond))
619 #define TRACE_EVENT_SYSCALL(name, proto, args, struct, assign,	\
620 			    print, reg, unreg)			\
621 	DECLARE_TRACE_SYSCALL(name, PARAMS(proto), PARAMS(args))
622 
623 #define TRACE_EVENT_FLAGS(event, flag)
624 
625 #define TRACE_EVENT_PERF_PERM(event, expr...)
626 
627 #define DECLARE_EVENT_NOP(name, proto, args)				\
628 	static inline void trace_##name(proto)				\
629 	{ }								\
630 	static inline bool trace_##name##_enabled(void)			\
631 	{								\
632 		return false;						\
633 	}
634 
635 #define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)	\
636 	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
637 
638 #define DECLARE_EVENT_CLASS_NOP(name, proto, args, tstruct, assign, print)
639 #define DEFINE_EVENT_NOP(template, name, proto, args)			\
640 	DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
641 
642 #endif /* ifdef TRACE_EVENT (see note above) */
643