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 <mathieu.desnoyers@efficios.com>
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/tracepoint-defs.h>
21 #include <linux/static_call.h>
22
23 struct module;
24 struct tracepoint;
25 struct notifier_block;
26
27 struct trace_eval_map {
28 const char *system;
29 const char *eval_string;
30 unsigned long eval_value;
31 };
32
33 #define TRACEPOINT_DEFAULT_PRIO 10
34
35 extern struct srcu_struct tracepoint_srcu;
36
37 extern int
38 tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
39 extern int
40 tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data,
41 int prio);
42 extern int
43 tracepoint_probe_register_prio_may_exist(struct tracepoint *tp, void *probe, void *data,
44 int prio);
45 extern int
46 tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
47 static inline int
tracepoint_probe_register_may_exist(struct tracepoint * tp,void * probe,void * data)48 tracepoint_probe_register_may_exist(struct tracepoint *tp, void *probe,
49 void *data)
50 {
51 return tracepoint_probe_register_prio_may_exist(tp, probe, data,
52 TRACEPOINT_DEFAULT_PRIO);
53 }
54 extern void
55 for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
56 void *priv);
57
58 #ifdef CONFIG_MODULES
59 struct tp_module {
60 struct list_head list;
61 struct module *mod;
62 };
63
64 bool trace_module_has_bad_taint(struct module *mod);
65 extern int register_tracepoint_module_notifier(struct notifier_block *nb);
66 extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
67 void for_each_module_tracepoint(void (*fct)(struct tracepoint *,
68 struct module *, void *),
69 void *priv);
70 void for_each_tracepoint_in_module(struct module *,
71 void (*fct)(struct tracepoint *,
72 struct module *, void *),
73 void *priv);
74 #else
trace_module_has_bad_taint(struct module * mod)75 static inline bool trace_module_has_bad_taint(struct module *mod)
76 {
77 return false;
78 }
79 static inline
register_tracepoint_module_notifier(struct notifier_block * nb)80 int register_tracepoint_module_notifier(struct notifier_block *nb)
81 {
82 return 0;
83 }
84 static inline
unregister_tracepoint_module_notifier(struct notifier_block * nb)85 int unregister_tracepoint_module_notifier(struct notifier_block *nb)
86 {
87 return 0;
88 }
89 static inline
for_each_module_tracepoint(void (* fct)(struct tracepoint *,struct module *,void *),void * priv)90 void for_each_module_tracepoint(void (*fct)(struct tracepoint *,
91 struct module *, void *),
92 void *priv)
93 {
94 }
95 static inline
for_each_tracepoint_in_module(struct module * mod,void (* fct)(struct tracepoint *,struct module *,void *),void * priv)96 void for_each_tracepoint_in_module(struct module *mod,
97 void (*fct)(struct tracepoint *,
98 struct module *, void *),
99 void *priv)
100 {
101 }
102 #endif /* CONFIG_MODULES */
103
104 /*
105 * tracepoint_synchronize_unregister must be called between the last tracepoint
106 * probe unregistration and the end of module exit to make sure there is no
107 * caller executing a probe when it is freed.
108 */
109 #ifdef CONFIG_TRACEPOINTS
tracepoint_synchronize_unregister(void)110 static inline void tracepoint_synchronize_unregister(void)
111 {
112 synchronize_srcu(&tracepoint_srcu);
113 synchronize_rcu();
114 }
115 #else
tracepoint_synchronize_unregister(void)116 static inline void tracepoint_synchronize_unregister(void)
117 { }
118 #endif
119
120 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
121 extern int syscall_regfunc(void);
122 extern void syscall_unregfunc(void);
123 #endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
124
125 #ifndef PARAMS
126 #define PARAMS(args...) args
127 #endif
128
129 #define TRACE_DEFINE_ENUM(x)
130 #define TRACE_DEFINE_SIZEOF(x)
131
132 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
tracepoint_ptr_deref(tracepoint_ptr_t * p)133 static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
134 {
135 return offset_to_ptr(p);
136 }
137
138 #define __TRACEPOINT_ENTRY(name) \
139 asm(" .section \"__tracepoints_ptrs\", \"a\" \n" \
140 " .balign 4 \n" \
141 " .long __tracepoint_" #name " - . \n" \
142 " .previous \n")
143 #else
tracepoint_ptr_deref(tracepoint_ptr_t * p)144 static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
145 {
146 return *p;
147 }
148
149 #define __TRACEPOINT_ENTRY(name) \
150 static tracepoint_ptr_t __tracepoint_ptr_##name __used \
151 __section("__tracepoints_ptrs") = &__tracepoint_##name
152 #endif
153
154 #endif /* _LINUX_TRACEPOINT_H */
155
156 /*
157 * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
158 * file ifdef protection.
159 * This is due to the way trace events work. If a file includes two
160 * trace event headers under one "CREATE_TRACE_POINTS" the first include
161 * will override the TRACE_EVENT and break the second include.
162 */
163
164 #ifndef DECLARE_TRACE
165
166 #define TP_PROTO(args...) args
167 #define TP_ARGS(args...) args
168 #define TP_CONDITION(args...) args
169
170 /*
171 * Individual subsystem my have a separate configuration to
172 * enable their tracepoints. By default, this file will create
173 * the tracepoints if CONFIG_TRACEPOINTS is defined. If a subsystem
174 * wants to be able to disable its tracepoints from being created
175 * it can define NOTRACE before including the tracepoint headers.
176 */
177 #if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE)
178 #define TRACEPOINTS_ENABLED
179 #endif
180
181 #ifdef TRACEPOINTS_ENABLED
182
183 #ifdef CONFIG_HAVE_STATIC_CALL
184 #define __DO_TRACE_CALL(name, args) \
185 do { \
186 struct tracepoint_func *it_func_ptr; \
187 void *__data; \
188 it_func_ptr = \
189 rcu_dereference_raw((&__tracepoint_##name)->funcs); \
190 if (it_func_ptr) { \
191 __data = (it_func_ptr)->data; \
192 static_call(tp_func_##name)(__data, args); \
193 } \
194 } while (0)
195 #else
196 #define __DO_TRACE_CALL(name, args) __traceiter_##name(NULL, args)
197 #endif /* CONFIG_HAVE_STATIC_CALL */
198
199 /*
200 * ARCH_WANTS_NO_INSTR archs are expected to have sanitized entry and idle
201 * code that disallow any/all tracing/instrumentation when RCU isn't watching.
202 */
203 #ifdef CONFIG_ARCH_WANTS_NO_INSTR
204 #define RCUIDLE_COND(rcuidle) (rcuidle)
205 #else
206 /* srcu can't be used from NMI */
207 #define RCUIDLE_COND(rcuidle) (rcuidle && in_nmi())
208 #endif
209
210 /*
211 * it_func[0] is never NULL because there is at least one element in the array
212 * when the array itself is non NULL.
213 */
214 #define __DO_TRACE(name, args, cond, rcuidle) \
215 do { \
216 int __maybe_unused __idx = 0; \
217 \
218 if (!(cond)) \
219 return; \
220 \
221 if (WARN_ONCE(RCUIDLE_COND(rcuidle), \
222 "Bad RCU usage for tracepoint")) \
223 return; \
224 \
225 /* keep srcu and sched-rcu usage consistent */ \
226 preempt_disable_notrace(); \
227 \
228 /* \
229 * For rcuidle callers, use srcu since sched-rcu \
230 * doesn't work from the idle path. \
231 */ \
232 if (rcuidle) { \
233 __idx = srcu_read_lock_notrace(&tracepoint_srcu);\
234 ct_irq_enter_irqson(); \
235 } \
236 \
237 __DO_TRACE_CALL(name, TP_ARGS(args)); \
238 \
239 if (rcuidle) { \
240 ct_irq_exit_irqson(); \
241 srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\
242 } \
243 \
244 preempt_enable_notrace(); \
245 } while (0)
246
247 #ifndef MODULE
248 #define __DECLARE_TRACE_RCU(name, proto, args, cond) \
249 static inline void trace_##name##_rcuidle(proto) \
250 { \
251 if (static_key_false(&__tracepoint_##name.key)) \
252 __DO_TRACE(name, \
253 TP_ARGS(args), \
254 TP_CONDITION(cond), 1); \
255 }
256 #else
257 #define __DECLARE_TRACE_RCU(name, proto, args, cond)
258 #endif
259
260 /*
261 * Declare an exported function that Rust code can call to trigger this
262 * tracepoint. This function does not include the static branch; that is done
263 * in Rust to avoid a function call when the tracepoint is disabled.
264 */
265 #define DEFINE_RUST_DO_TRACE(name, proto, args)
266 #define __DEFINE_RUST_DO_TRACE(name, proto, args) \
267 notrace void rust_do_trace_##name(proto) \
268 { \
269 __rust_do_trace_##name(args); \
270 }
271
272 /*
273 * Make sure the alignment of the structure in the __tracepoints section will
274 * not add unwanted padding between the beginning of the section and the
275 * structure. Force alignment to the same alignment as the section start.
276 *
277 * When lockdep is enabled, we make sure to always test if RCU is
278 * "watching" regardless if the tracepoint is enabled or not. Tracepoints
279 * require RCU to be active, and it should always warn at the tracepoint
280 * site if it is not watching, as it will need to be active when the
281 * tracepoint is enabled.
282 */
283 #define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
284 extern int __traceiter_##name(data_proto); \
285 DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \
286 extern struct tracepoint __tracepoint_##name; \
287 extern void rust_do_trace_##name(proto); \
288 static inline void __rust_do_trace_##name(proto) \
289 { \
290 __DO_TRACE(name, \
291 TP_ARGS(args), \
292 TP_CONDITION(cond), 0); \
293 } \
294 static inline void trace_##name(proto) \
295 { \
296 if (static_key_false(&__tracepoint_##name.key)) \
297 __DO_TRACE(name, \
298 TP_ARGS(args), \
299 TP_CONDITION(cond), 0); \
300 if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
301 WARN_ONCE(!rcu_is_watching(), \
302 "RCU not watching for tracepoint"); \
303 } \
304 } \
305 __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \
306 PARAMS(cond)) \
307 static inline int \
308 register_trace_##name(void (*probe)(data_proto), void *data) \
309 { \
310 return tracepoint_probe_register(&__tracepoint_##name, \
311 (void *)probe, data); \
312 } \
313 static inline int \
314 register_trace_prio_##name(void (*probe)(data_proto), void *data,\
315 int prio) \
316 { \
317 return tracepoint_probe_register_prio(&__tracepoint_##name, \
318 (void *)probe, data, prio); \
319 } \
320 static inline int \
321 unregister_trace_##name(void (*probe)(data_proto), void *data) \
322 { \
323 return tracepoint_probe_unregister(&__tracepoint_##name,\
324 (void *)probe, data); \
325 } \
326 static inline void \
327 check_trace_callback_type_##name(void (*cb)(data_proto)) \
328 { \
329 } \
330 static inline bool \
331 trace_##name##_enabled(void) \
332 { \
333 return static_key_false(&__tracepoint_##name.key); \
334 }
335
336 /*
337 * We have no guarantee that gcc and the linker won't up-align the tracepoint
338 * structures, so we create an array of pointers that will be used for iteration
339 * on the tracepoints.
340 */
341 #define DEFINE_TRACE_FN(_name, _reg, _unreg, proto, args) \
342 static const char __tpstrtab_##_name[] \
343 __section("__tracepoints_strings") = #_name; \
344 extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name); \
345 int __traceiter_##_name(void *__data, proto); \
346 void __probestub_##_name(void *__data, proto); \
347 struct tracepoint __tracepoint_##_name __used \
348 __section("__tracepoints") = { \
349 .name = __tpstrtab_##_name, \
350 .key = STATIC_KEY_INIT_FALSE, \
351 .static_call_key = &STATIC_CALL_KEY(tp_func_##_name), \
352 .static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
353 .iterator = &__traceiter_##_name, \
354 .probestub = &__probestub_##_name, \
355 .regfunc = _reg, \
356 .unregfunc = _unreg, \
357 .funcs = NULL }; \
358 __TRACEPOINT_ENTRY(_name); \
359 int __traceiter_##_name(void *__data, proto) \
360 { \
361 struct tracepoint_func *it_func_ptr; \
362 void *it_func; \
363 \
364 it_func_ptr = \
365 rcu_dereference_raw((&__tracepoint_##_name)->funcs); \
366 if (it_func_ptr) { \
367 do { \
368 it_func = READ_ONCE((it_func_ptr)->func); \
369 __data = (it_func_ptr)->data; \
370 ((void(*)(void *, proto))(it_func))(__data, args); \
371 } while ((++it_func_ptr)->func); \
372 } \
373 return 0; \
374 } \
375 void __probestub_##_name(void *__data, proto) \
376 { \
377 } \
378 DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); \
379 DEFINE_RUST_DO_TRACE(_name, TP_PROTO(proto), TP_ARGS(args))
380
381 #define DEFINE_TRACE(name, proto, args) \
382 DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args));
383
384 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
385 EXPORT_SYMBOL_GPL(__tracepoint_##name); \
386 EXPORT_SYMBOL_GPL(__traceiter_##name); \
387 EXPORT_STATIC_CALL_GPL(tp_func_##name)
388 #define EXPORT_TRACEPOINT_SYMBOL(name) \
389 EXPORT_SYMBOL(__tracepoint_##name); \
390 EXPORT_SYMBOL(__traceiter_##name); \
391 EXPORT_STATIC_CALL(tp_func_##name)
392
393
394 #else /* !TRACEPOINTS_ENABLED */
395 #define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
396 static inline void trace_##name(proto) \
397 { } \
398 static inline void trace_##name##_rcuidle(proto) \
399 { } \
400 static inline int \
401 register_trace_##name(void (*probe)(data_proto), \
402 void *data) \
403 { \
404 return -ENOSYS; \
405 } \
406 static inline int \
407 unregister_trace_##name(void (*probe)(data_proto), \
408 void *data) \
409 { \
410 return -ENOSYS; \
411 } \
412 static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
413 { \
414 } \
415 static inline bool \
416 trace_##name##_enabled(void) \
417 { \
418 return false; \
419 }
420
421 #define DEFINE_TRACE_FN(name, reg, unreg, proto, args)
422 #define DEFINE_TRACE(name, proto, args)
423 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
424 #define EXPORT_TRACEPOINT_SYMBOL(name)
425
426 #endif /* TRACEPOINTS_ENABLED */
427
428 #ifdef CONFIG_TRACING
429 /**
430 * tracepoint_string - register constant persistent string to trace system
431 * @str - a constant persistent string that will be referenced in tracepoints
432 *
433 * If constant strings are being used in tracepoints, it is faster and
434 * more efficient to just save the pointer to the string and reference
435 * that with a printf "%s" instead of saving the string in the ring buffer
436 * and wasting space and time.
437 *
438 * The problem with the above approach is that userspace tools that read
439 * the binary output of the trace buffers do not have access to the string.
440 * Instead they just show the address of the string which is not very
441 * useful to users.
442 *
443 * With tracepoint_string(), the string will be registered to the tracing
444 * system and exported to userspace via the debugfs/tracing/printk_formats
445 * file that maps the string address to the string text. This way userspace
446 * tools that read the binary buffers have a way to map the pointers to
447 * the ASCII strings they represent.
448 *
449 * The @str used must be a constant string and persistent as it would not
450 * make sense to show a string that no longer exists. But it is still fine
451 * to be used with modules, because when modules are unloaded, if they
452 * had tracepoints, the ring buffers are cleared too. As long as the string
453 * does not change during the life of the module, it is fine to use
454 * tracepoint_string() within a module.
455 */
456 #define tracepoint_string(str) \
457 ({ \
458 static const char *___tp_str __tracepoint_string = str; \
459 ___tp_str; \
460 })
461 #define __tracepoint_string __used __section("__tracepoint_str")
462 #else
463 /*
464 * tracepoint_string() is used to save the string address for userspace
465 * tracing tools. When tracing isn't configured, there's no need to save
466 * anything.
467 */
468 # define tracepoint_string(str) str
469 # define __tracepoint_string
470 #endif
471
472 #define DECLARE_TRACE(name, proto, args) \
473 __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
474 cpu_online(raw_smp_processor_id()), \
475 PARAMS(void *__data, proto))
476
477 #define DECLARE_TRACE_CONDITION(name, proto, args, cond) \
478 __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
479 cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \
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
620 #define TRACE_EVENT_FLAGS(event, flag)
621
622 #define TRACE_EVENT_PERF_PERM(event, expr...)
623
624 #define DECLARE_EVENT_NOP(name, proto, args) \
625 static inline void trace_##name(proto) \
626 { } \
627 static inline bool trace_##name##_enabled(void) \
628 { \
629 return false; \
630 }
631
632 #define TRACE_EVENT_NOP(name, proto, args, struct, assign, print) \
633 DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
634
635 #define DECLARE_EVENT_CLASS_NOP(name, proto, args, tstruct, assign, print)
636 #define DEFINE_EVENT_NOP(template, name, proto, args) \
637 DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
638
639 #endif /* ifdef TRACE_EVENT (see note above) */
640