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52a6e82a | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
97e1c18e MD |
2 | #ifndef _LINUX_TRACEPOINT_H |
3 | #define _LINUX_TRACEPOINT_H | |
4 | ||
5 | /* | |
6 | * Kernel Tracepoint API. | |
7 | * | |
ec15872d | 8 | * See Documentation/trace/tracepoints.rst. |
97e1c18e | 9 | * |
de7b2973 | 10 | * Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
97e1c18e MD |
11 | * |
12 | * Heavily inspired from the Linux Kernel Markers. | |
97e1c18e MD |
13 | */ |
14 | ||
f3775549 | 15 | #include <linux/smp.h> |
e6753f23 | 16 | #include <linux/srcu.h> |
b70e4f05 | 17 | #include <linux/errno.h> |
97e1c18e | 18 | #include <linux/types.h> |
f3775549 | 19 | #include <linux/cpumask.h> |
97e1c18e | 20 | #include <linux/rcupdate.h> |
bd2a634d | 21 | #include <linux/tracepoint-defs.h> |
d25e37d8 | 22 | #include <linux/static_call.h> |
97e1c18e MD |
23 | |
24 | struct module; | |
25 | struct tracepoint; | |
de7b2973 | 26 | struct notifier_block; |
97e1c18e | 27 | |
00f4b652 | 28 | struct trace_eval_map { |
0c564a53 | 29 | const char *system; |
00f4b652 JL |
30 | const char *eval_string; |
31 | unsigned long eval_value; | |
0c564a53 SRRH |
32 | }; |
33 | ||
7904b5c4 SRRH |
34 | #define TRACEPOINT_DEFAULT_PRIO 10 |
35 | ||
e6753f23 JFG |
36 | extern struct srcu_struct tracepoint_srcu; |
37 | ||
38516ab5 | 38 | extern int |
de7b2973 MD |
39 | tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data); |
40 | extern int | |
7904b5c4 SRRH |
41 | tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data, |
42 | int prio); | |
43 | extern int | |
de7b2973 MD |
44 | tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data); |
45 | extern void | |
46 | for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv), | |
47 | void *priv); | |
2e26ca71 | 48 | |
b75ef8b4 MD |
49 | #ifdef CONFIG_MODULES |
50 | struct tp_module { | |
51 | struct list_head list; | |
eb7d035c | 52 | struct module *mod; |
b75ef8b4 | 53 | }; |
de7b2973 | 54 | |
45ab2813 | 55 | bool trace_module_has_bad_taint(struct module *mod); |
de7b2973 MD |
56 | extern int register_tracepoint_module_notifier(struct notifier_block *nb); |
57 | extern int unregister_tracepoint_module_notifier(struct notifier_block *nb); | |
45ab2813 SRRH |
58 | #else |
59 | static inline bool trace_module_has_bad_taint(struct module *mod) | |
60 | { | |
61 | return false; | |
62 | } | |
de7b2973 MD |
63 | static inline |
64 | int register_tracepoint_module_notifier(struct notifier_block *nb) | |
65 | { | |
66 | return 0; | |
67 | } | |
68 | static inline | |
69 | int unregister_tracepoint_module_notifier(struct notifier_block *nb) | |
70 | { | |
71 | return 0; | |
72 | } | |
b75ef8b4 MD |
73 | #endif /* CONFIG_MODULES */ |
74 | ||
2e26ca71 SR |
75 | /* |
76 | * tracepoint_synchronize_unregister must be called between the last tracepoint | |
77 | * probe unregistration and the end of module exit to make sure there is no | |
78 | * caller executing a probe when it is freed. | |
79 | */ | |
e6753f23 | 80 | #ifdef CONFIG_TRACEPOINTS |
2e26ca71 SR |
81 | static inline void tracepoint_synchronize_unregister(void) |
82 | { | |
e6753f23 | 83 | synchronize_srcu(&tracepoint_srcu); |
74401729 | 84 | synchronize_rcu(); |
2e26ca71 | 85 | } |
e6753f23 JFG |
86 | #else |
87 | static inline void tracepoint_synchronize_unregister(void) | |
88 | { } | |
89 | #endif | |
2e26ca71 | 90 | |
b725dfea | 91 | #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS |
8cf868af | 92 | extern int syscall_regfunc(void); |
b725dfea MD |
93 | extern void syscall_unregfunc(void); |
94 | #endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */ | |
95 | ||
d25e37d8 | 96 | #ifndef PARAMS |
2e26ca71 | 97 | #define PARAMS(args...) args |
d25e37d8 | 98 | #endif |
2e26ca71 | 99 | |
0c564a53 | 100 | #define TRACE_DEFINE_ENUM(x) |
4f0dfd76 | 101 | #define TRACE_DEFINE_SIZEOF(x) |
0c564a53 | 102 | |
9c0be3f6 MD |
103 | #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS |
104 | static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) | |
105 | { | |
106 | return offset_to_ptr(p); | |
107 | } | |
108 | ||
109 | #define __TRACEPOINT_ENTRY(name) \ | |
110 | asm(" .section \"__tracepoints_ptrs\", \"a\" \n" \ | |
111 | " .balign 4 \n" \ | |
112 | " .long __tracepoint_" #name " - . \n" \ | |
113 | " .previous \n") | |
114 | #else | |
115 | static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) | |
116 | { | |
117 | return *p; | |
118 | } | |
119 | ||
120 | #define __TRACEPOINT_ENTRY(name) \ | |
121 | static tracepoint_ptr_t __tracepoint_ptr_##name __used \ | |
33def849 | 122 | __section("__tracepoints_ptrs") = &__tracepoint_##name |
9c0be3f6 MD |
123 | #endif |
124 | ||
2e26ca71 SR |
125 | #endif /* _LINUX_TRACEPOINT_H */ |
126 | ||
127 | /* | |
128 | * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include | |
129 | * file ifdef protection. | |
130 | * This is due to the way trace events work. If a file includes two | |
131 | * trace event headers under one "CREATE_TRACE_POINTS" the first include | |
132 | * will override the TRACE_EVENT and break the second include. | |
133 | */ | |
134 | ||
ea20d929 SR |
135 | #ifndef DECLARE_TRACE |
136 | ||
2939b046 | 137 | #define TP_PROTO(args...) args |
8cd09a59 | 138 | #define TP_ARGS(args...) args |
287050d3 | 139 | #define TP_CONDITION(args...) args |
97e1c18e | 140 | |
c63b7682 TS |
141 | /* |
142 | * Individual subsystem my have a separate configuration to | |
143 | * enable their tracepoints. By default, this file will create | |
144 | * the tracepoints if CONFIG_TRACEPOINT is defined. If a subsystem | |
145 | * wants to be able to disable its tracepoints from being created | |
146 | * it can define NOTRACE before including the tracepoint headers. | |
147 | */ | |
148 | #if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE) | |
149 | #define TRACEPOINTS_ENABLED | |
150 | #endif | |
151 | ||
152 | #ifdef TRACEPOINTS_ENABLED | |
97e1c18e | 153 | |
d25e37d8 SRV |
154 | #ifdef CONFIG_HAVE_STATIC_CALL |
155 | #define __DO_TRACE_CALL(name) static_call(tp_func_##name) | |
156 | #else | |
de394e75 | 157 | #define __DO_TRACE_CALL(name) __traceiter_##name |
d25e37d8 SRV |
158 | #endif /* CONFIG_HAVE_STATIC_CALL */ |
159 | ||
97e1c18e MD |
160 | /* |
161 | * it_func[0] is never NULL because there is at least one element in the array | |
162 | * when the array itself is non NULL. | |
38516ab5 SR |
163 | * |
164 | * Note, the proto and args passed in includes "__data" as the first parameter. | |
165 | * The reason for this is to handle the "void" prototype. If a tracepoint | |
166 | * has a "void" prototype, then it is invalid to declare a function | |
a2806ef7 | 167 | * as "(void *, void)". |
97e1c18e | 168 | */ |
d25e37d8 | 169 | #define __DO_TRACE(name, proto, args, cond, rcuidle) \ |
97e1c18e | 170 | do { \ |
38516ab5 | 171 | struct tracepoint_func *it_func_ptr; \ |
0c7a52e4 | 172 | int __maybe_unused __idx = 0; \ |
d25e37d8 | 173 | void *__data; \ |
97e1c18e | 174 | \ |
287050d3 SR |
175 | if (!(cond)) \ |
176 | return; \ | |
e6753f23 JFG |
177 | \ |
178 | /* srcu can't be used from NMI */ \ | |
179 | WARN_ON_ONCE(rcuidle && in_nmi()); \ | |
180 | \ | |
181 | /* keep srcu and sched-rcu usage consistent */ \ | |
182 | preempt_disable_notrace(); \ | |
183 | \ | |
184 | /* \ | |
185 | * For rcuidle callers, use srcu since sched-rcu \ | |
186 | * doesn't work from the idle path. \ | |
187 | */ \ | |
865e63b0 | 188 | if (rcuidle) { \ |
0c7a52e4 | 189 | __idx = srcu_read_lock_notrace(&tracepoint_srcu);\ |
865e63b0 SRV |
190 | rcu_irq_enter_irqson(); \ |
191 | } \ | |
e6753f23 | 192 | \ |
d25e37d8 SRV |
193 | it_func_ptr = \ |
194 | rcu_dereference_raw((&__tracepoint_##name)->funcs); \ | |
38516ab5 | 195 | if (it_func_ptr) { \ |
d25e37d8 SRV |
196 | __data = (it_func_ptr)->data; \ |
197 | __DO_TRACE_CALL(name)(args); \ | |
97e1c18e | 198 | } \ |
e6753f23 | 199 | \ |
865e63b0 SRV |
200 | if (rcuidle) { \ |
201 | rcu_irq_exit_irqson(); \ | |
0c7a52e4 | 202 | srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\ |
865e63b0 | 203 | } \ |
e6753f23 JFG |
204 | \ |
205 | preempt_enable_notrace(); \ | |
97e1c18e MD |
206 | } while (0) |
207 | ||
7ece55a4 | 208 | #ifndef MODULE |
d54b6eeb | 209 | #define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) \ |
7ece55a4 JT |
210 | static inline void trace_##name##_rcuidle(proto) \ |
211 | { \ | |
212 | if (static_key_false(&__tracepoint_##name.key)) \ | |
d25e37d8 | 213 | __DO_TRACE(name, \ |
7ece55a4 JT |
214 | TP_PROTO(data_proto), \ |
215 | TP_ARGS(data_args), \ | |
d54b6eeb | 216 | TP_CONDITION(cond), 1); \ |
7ece55a4 JT |
217 | } |
218 | #else | |
219 | #define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) | |
220 | #endif | |
221 | ||
97e1c18e MD |
222 | /* |
223 | * Make sure the alignment of the structure in the __tracepoints section will | |
224 | * not add unwanted padding between the beginning of the section and the | |
225 | * structure. Force alignment to the same alignment as the section start. | |
3a630178 DH |
226 | * |
227 | * When lockdep is enabled, we make sure to always do the RCU portions of | |
a15920be MD |
228 | * the tracepoint code, regardless of whether tracing is on. However, |
229 | * don't check if the condition is false, due to interaction with idle | |
230 | * instrumentation. This lets us find RCU issues triggered with tracepoints | |
231 | * even when this tracepoint is off. This code has no purpose other than | |
232 | * poking RCU a bit. | |
97e1c18e | 233 | */ |
2fbb90db | 234 | #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ |
de394e75 | 235 | extern int __traceiter_##name(data_proto); \ |
236 | DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \ | |
7e066fb8 | 237 | extern struct tracepoint __tracepoint_##name; \ |
97e1c18e MD |
238 | static inline void trace_##name(proto) \ |
239 | { \ | |
c5905afb | 240 | if (static_key_false(&__tracepoint_##name.key)) \ |
d25e37d8 | 241 | __DO_TRACE(name, \ |
38516ab5 | 242 | TP_PROTO(data_proto), \ |
287050d3 | 243 | TP_ARGS(data_args), \ |
d54b6eeb | 244 | TP_CONDITION(cond), 0); \ |
a05d59a5 | 245 | if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \ |
3a630178 DH |
246 | rcu_read_lock_sched_notrace(); \ |
247 | rcu_dereference_sched(__tracepoint_##name.funcs);\ | |
248 | rcu_read_unlock_sched_notrace(); \ | |
249 | } \ | |
2fbb90db | 250 | } \ |
7ece55a4 JT |
251 | __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \ |
252 | PARAMS(cond), PARAMS(data_proto), PARAMS(data_args)) \ | |
38516ab5 SR |
253 | static inline int \ |
254 | register_trace_##name(void (*probe)(data_proto), void *data) \ | |
97e1c18e | 255 | { \ |
de7b2973 MD |
256 | return tracepoint_probe_register(&__tracepoint_##name, \ |
257 | (void *)probe, data); \ | |
97e1c18e | 258 | } \ |
38516ab5 | 259 | static inline int \ |
7904b5c4 SRRH |
260 | register_trace_prio_##name(void (*probe)(data_proto), void *data,\ |
261 | int prio) \ | |
262 | { \ | |
263 | return tracepoint_probe_register_prio(&__tracepoint_##name, \ | |
264 | (void *)probe, data, prio); \ | |
265 | } \ | |
266 | static inline int \ | |
38516ab5 | 267 | unregister_trace_##name(void (*probe)(data_proto), void *data) \ |
97e1c18e | 268 | { \ |
de7b2973 MD |
269 | return tracepoint_probe_unregister(&__tracepoint_##name,\ |
270 | (void *)probe, data); \ | |
53da59aa | 271 | } \ |
38516ab5 SR |
272 | static inline void \ |
273 | check_trace_callback_type_##name(void (*cb)(data_proto)) \ | |
53da59aa | 274 | { \ |
7c65bbc7 SRRH |
275 | } \ |
276 | static inline bool \ | |
277 | trace_##name##_enabled(void) \ | |
278 | { \ | |
279 | return static_key_false(&__tracepoint_##name.key); \ | |
97e1c18e MD |
280 | } |
281 | ||
65498646 MD |
282 | /* |
283 | * We have no guarantee that gcc and the linker won't up-align the tracepoint | |
284 | * structures, so we create an array of pointers that will be used for iteration | |
285 | * on the tracepoints. | |
286 | */ | |
d25e37d8 SRV |
287 | #define DEFINE_TRACE_FN(_name, _reg, _unreg, proto, args) \ |
288 | static const char __tpstrtab_##_name[] \ | |
33def849 | 289 | __section("__tracepoints_strings") = #_name; \ |
d25e37d8 | 290 | extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name); \ |
de394e75 | 291 | int __traceiter_##_name(void *__data, proto); \ |
d25e37d8 | 292 | struct tracepoint __tracepoint_##_name __used \ |
33def849 | 293 | __section("__tracepoints") = { \ |
d25e37d8 SRV |
294 | .name = __tpstrtab_##_name, \ |
295 | .key = STATIC_KEY_INIT_FALSE, \ | |
296 | .static_call_key = &STATIC_CALL_KEY(tp_func_##_name), \ | |
297 | .static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \ | |
de394e75 | 298 | .iterator = &__traceiter_##_name, \ |
d25e37d8 SRV |
299 | .regfunc = _reg, \ |
300 | .unregfunc = _unreg, \ | |
301 | .funcs = NULL }; \ | |
302 | __TRACEPOINT_ENTRY(_name); \ | |
de394e75 | 303 | int __traceiter_##_name(void *__data, proto) \ |
d25e37d8 SRV |
304 | { \ |
305 | struct tracepoint_func *it_func_ptr; \ | |
306 | void *it_func; \ | |
307 | \ | |
308 | it_func_ptr = \ | |
309 | rcu_dereference_raw((&__tracepoint_##_name)->funcs); \ | |
310 | do { \ | |
311 | it_func = (it_func_ptr)->func; \ | |
312 | __data = (it_func_ptr)->data; \ | |
313 | ((void(*)(void *, proto))(it_func))(__data, args); \ | |
314 | } while ((++it_func_ptr)->func); \ | |
315 | return 0; \ | |
316 | } \ | |
de394e75 | 317 | DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); |
97419875 | 318 | |
d25e37d8 SRV |
319 | #define DEFINE_TRACE(name, proto, args) \ |
320 | DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args)); | |
7e066fb8 MD |
321 | |
322 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \ | |
d25e37d8 | 323 | EXPORT_SYMBOL_GPL(__tracepoint_##name); \ |
de394e75 | 324 | EXPORT_SYMBOL_GPL(__traceiter_##name); \ |
d25e37d8 | 325 | EXPORT_STATIC_CALL_GPL(tp_func_##name) |
7e066fb8 | 326 | #define EXPORT_TRACEPOINT_SYMBOL(name) \ |
d25e37d8 | 327 | EXPORT_SYMBOL(__tracepoint_##name); \ |
de394e75 | 328 | EXPORT_SYMBOL(__traceiter_##name); \ |
d25e37d8 SRV |
329 | EXPORT_STATIC_CALL(tp_func_##name) |
330 | ||
7e066fb8 | 331 | |
c63b7682 | 332 | #else /* !TRACEPOINTS_ENABLED */ |
2fbb90db | 333 | #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ |
97e1c18e MD |
334 | static inline void trace_##name(proto) \ |
335 | { } \ | |
2fbb90db SR |
336 | static inline void trace_##name##_rcuidle(proto) \ |
337 | { } \ | |
38516ab5 SR |
338 | static inline int \ |
339 | register_trace_##name(void (*probe)(data_proto), \ | |
340 | void *data) \ | |
97e1c18e MD |
341 | { \ |
342 | return -ENOSYS; \ | |
343 | } \ | |
38516ab5 SR |
344 | static inline int \ |
345 | unregister_trace_##name(void (*probe)(data_proto), \ | |
346 | void *data) \ | |
c420970e MD |
347 | { \ |
348 | return -ENOSYS; \ | |
53da59aa | 349 | } \ |
38516ab5 | 350 | static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \ |
53da59aa | 351 | { \ |
7c65bbc7 SRRH |
352 | } \ |
353 | static inline bool \ | |
354 | trace_##name##_enabled(void) \ | |
355 | { \ | |
356 | return false; \ | |
c420970e | 357 | } |
97e1c18e | 358 | |
d25e37d8 SRV |
359 | #define DEFINE_TRACE_FN(name, reg, unreg, proto, args) |
360 | #define DEFINE_TRACE(name, proto, args) | |
7e066fb8 MD |
361 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) |
362 | #define EXPORT_TRACEPOINT_SYMBOL(name) | |
363 | ||
c63b7682 | 364 | #endif /* TRACEPOINTS_ENABLED */ |
38516ab5 | 365 | |
3c49b52b SR |
366 | #ifdef CONFIG_TRACING |
367 | /** | |
368 | * tracepoint_string - register constant persistent string to trace system | |
369 | * @str - a constant persistent string that will be referenced in tracepoints | |
370 | * | |
371 | * If constant strings are being used in tracepoints, it is faster and | |
372 | * more efficient to just save the pointer to the string and reference | |
373 | * that with a printf "%s" instead of saving the string in the ring buffer | |
374 | * and wasting space and time. | |
375 | * | |
376 | * The problem with the above approach is that userspace tools that read | |
377 | * the binary output of the trace buffers do not have access to the string. | |
378 | * Instead they just show the address of the string which is not very | |
379 | * useful to users. | |
380 | * | |
381 | * With tracepoint_string(), the string will be registered to the tracing | |
382 | * system and exported to userspace via the debugfs/tracing/printk_formats | |
383 | * file that maps the string address to the string text. This way userspace | |
384 | * tools that read the binary buffers have a way to map the pointers to | |
385 | * the ASCII strings they represent. | |
386 | * | |
387 | * The @str used must be a constant string and persistent as it would not | |
388 | * make sense to show a string that no longer exists. But it is still fine | |
389 | * to be used with modules, because when modules are unloaded, if they | |
390 | * had tracepoints, the ring buffers are cleared too. As long as the string | |
391 | * does not change during the life of the module, it is fine to use | |
392 | * tracepoint_string() within a module. | |
393 | */ | |
394 | #define tracepoint_string(str) \ | |
395 | ({ \ | |
396 | static const char *___tp_str __tracepoint_string = str; \ | |
397 | ___tp_str; \ | |
398 | }) | |
33def849 | 399 | #define __tracepoint_string __used __section("__tracepoint_str") |
3c49b52b SR |
400 | #else |
401 | /* | |
402 | * tracepoint_string() is used to save the string address for userspace | |
403 | * tracing tools. When tracing isn't configured, there's no need to save | |
404 | * anything. | |
405 | */ | |
406 | # define tracepoint_string(str) str | |
407 | # define __tracepoint_string | |
408 | #endif | |
409 | ||
38516ab5 | 410 | #define DECLARE_TRACE(name, proto, args) \ |
dc17147d SRRH |
411 | __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ |
412 | cpu_online(raw_smp_processor_id()), \ | |
413 | PARAMS(void *__data, proto), \ | |
414 | PARAMS(__data, args)) | |
38516ab5 | 415 | |
287050d3 | 416 | #define DECLARE_TRACE_CONDITION(name, proto, args, cond) \ |
dc17147d SRRH |
417 | __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \ |
418 | cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \ | |
287050d3 SR |
419 | PARAMS(void *__data, proto), \ |
420 | PARAMS(__data, args)) | |
421 | ||
1ed0c597 FW |
422 | #define TRACE_EVENT_FLAGS(event, flag) |
423 | ||
d5b5f391 PZ |
424 | #define TRACE_EVENT_PERF_PERM(event, expr...) |
425 | ||
ea20d929 | 426 | #endif /* DECLARE_TRACE */ |
97e1c18e | 427 | |
ea20d929 | 428 | #ifndef TRACE_EVENT |
823f9124 SR |
429 | /* |
430 | * For use with the TRACE_EVENT macro: | |
431 | * | |
432 | * We define a tracepoint, its arguments, its printk format | |
2621bca8 | 433 | * and its 'fast binary record' layout. |
823f9124 SR |
434 | * |
435 | * Firstly, name your tracepoint via TRACE_EVENT(name : the | |
436 | * 'subsystem_event' notation is fine. | |
437 | * | |
438 | * Think about this whole construct as the | |
439 | * 'trace_sched_switch() function' from now on. | |
440 | * | |
441 | * | |
442 | * TRACE_EVENT(sched_switch, | |
443 | * | |
444 | * * | |
445 | * * A function has a regular function arguments | |
446 | * * prototype, declare it via TP_PROTO(): | |
447 | * * | |
448 | * | |
ef18012b SR |
449 | * TP_PROTO(struct rq *rq, struct task_struct *prev, |
450 | * struct task_struct *next), | |
823f9124 SR |
451 | * |
452 | * * | |
453 | * * Define the call signature of the 'function'. | |
454 | * * (Design sidenote: we use this instead of a | |
455 | * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.) | |
456 | * * | |
457 | * | |
ef18012b | 458 | * TP_ARGS(rq, prev, next), |
823f9124 SR |
459 | * |
460 | * * | |
461 | * * Fast binary tracing: define the trace record via | |
462 | * * TP_STRUCT__entry(). You can think about it like a | |
463 | * * regular C structure local variable definition. | |
464 | * * | |
465 | * * This is how the trace record is structured and will | |
466 | * * be saved into the ring buffer. These are the fields | |
467 | * * that will be exposed to user-space in | |
156f5a78 | 468 | * * /sys/kernel/debug/tracing/events/<*>/format. |
823f9124 SR |
469 | * * |
470 | * * The declared 'local variable' is called '__entry' | |
471 | * * | |
472 | * * __field(pid_t, prev_prid) is equivalent to a standard declariton: | |
473 | * * | |
474 | * * pid_t prev_pid; | |
475 | * * | |
476 | * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to: | |
477 | * * | |
478 | * * char prev_comm[TASK_COMM_LEN]; | |
479 | * * | |
480 | * | |
481 | * TP_STRUCT__entry( | |
482 | * __array( char, prev_comm, TASK_COMM_LEN ) | |
483 | * __field( pid_t, prev_pid ) | |
484 | * __field( int, prev_prio ) | |
485 | * __array( char, next_comm, TASK_COMM_LEN ) | |
486 | * __field( pid_t, next_pid ) | |
487 | * __field( int, next_prio ) | |
488 | * ), | |
489 | * | |
490 | * * | |
491 | * * Assign the entry into the trace record, by embedding | |
492 | * * a full C statement block into TP_fast_assign(). You | |
493 | * * can refer to the trace record as '__entry' - | |
494 | * * otherwise you can put arbitrary C code in here. | |
495 | * * | |
496 | * * Note: this C code will execute every time a trace event | |
497 | * * happens, on an active tracepoint. | |
498 | * * | |
499 | * | |
ef18012b SR |
500 | * TP_fast_assign( |
501 | * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); | |
502 | * __entry->prev_pid = prev->pid; | |
503 | * __entry->prev_prio = prev->prio; | |
823f9124 SR |
504 | * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); |
505 | * __entry->next_pid = next->pid; | |
ef18012b | 506 | * __entry->next_prio = next->prio; |
ec6e7c3a | 507 | * ), |
823f9124 SR |
508 | * |
509 | * * | |
510 | * * Formatted output of a trace record via TP_printk(). | |
511 | * * This is how the tracepoint will appear under ftrace | |
512 | * * plugins that make use of this tracepoint. | |
513 | * * | |
514 | * * (raw-binary tracing wont actually perform this step.) | |
515 | * * | |
516 | * | |
517 | * TP_printk("task %s:%d [%d] ==> %s:%d [%d]", | |
518 | * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio, | |
519 | * __entry->next_comm, __entry->next_pid, __entry->next_prio), | |
520 | * | |
521 | * ); | |
522 | * | |
523 | * This macro construct is thus used for the regular printk format | |
524 | * tracing setup, it is used to construct a function pointer based | |
525 | * tracepoint callback (this is used by programmatic plugins and | |
526 | * can also by used by generic instrumentation like SystemTap), and | |
527 | * it is also used to expose a structured trace record in | |
156f5a78 | 528 | * /sys/kernel/debug/tracing/events/. |
97419875 JS |
529 | * |
530 | * A set of (un)registration functions can be passed to the variant | |
531 | * TRACE_EVENT_FN to perform any (un)registration work. | |
823f9124 SR |
532 | */ |
533 | ||
091ad365 | 534 | #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print) |
ff038f5c SR |
535 | #define DEFINE_EVENT(template, name, proto, args) \ |
536 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) | |
f5abaa1b SR |
537 | #define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\ |
538 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) | |
e5bc9721 SR |
539 | #define DEFINE_EVENT_PRINT(template, name, proto, args, print) \ |
540 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) | |
287050d3 SR |
541 | #define DEFINE_EVENT_CONDITION(template, name, proto, \ |
542 | args, cond) \ | |
543 | DECLARE_TRACE_CONDITION(name, PARAMS(proto), \ | |
544 | PARAMS(args), PARAMS(cond)) | |
ff038f5c | 545 | |
30a8fecc | 546 | #define TRACE_EVENT(name, proto, args, struct, assign, print) \ |
da4d0302 | 547 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) |
97419875 JS |
548 | #define TRACE_EVENT_FN(name, proto, args, struct, \ |
549 | assign, print, reg, unreg) \ | |
550 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) | |
2701121b DK |
551 | #define TRACE_EVENT_FN_COND(name, proto, args, cond, struct, \ |
552 | assign, print, reg, unreg) \ | |
553 | DECLARE_TRACE_CONDITION(name, PARAMS(proto), \ | |
554 | PARAMS(args), PARAMS(cond)) | |
287050d3 SR |
555 | #define TRACE_EVENT_CONDITION(name, proto, args, cond, \ |
556 | struct, assign, print) \ | |
557 | DECLARE_TRACE_CONDITION(name, PARAMS(proto), \ | |
558 | PARAMS(args), PARAMS(cond)) | |
7cb2e3ee | 559 | |
1ed0c597 FW |
560 | #define TRACE_EVENT_FLAGS(event, flag) |
561 | ||
d5b5f391 PZ |
562 | #define TRACE_EVENT_PERF_PERM(event, expr...) |
563 | ||
16336345 YS |
564 | #define DECLARE_EVENT_NOP(name, proto, args) \ |
565 | static inline void trace_##name(proto) \ | |
566 | { } \ | |
567 | static inline bool trace_##name##_enabled(void) \ | |
568 | { \ | |
569 | return false; \ | |
570 | } | |
571 | ||
572 | #define TRACE_EVENT_NOP(name, proto, args, struct, assign, print) \ | |
573 | DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args)) | |
574 | ||
575 | #define DECLARE_EVENT_CLASS_NOP(name, proto, args, tstruct, assign, print) | |
576 | #define DEFINE_EVENT_NOP(template, name, proto, args) \ | |
577 | DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args)) | |
578 | ||
7cb2e3ee | 579 | #endif /* ifdef TRACE_EVENT (see note above) */ |