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27b052e3 PMF |
1 | #ifndef _UST_TRACEPOINT_H |
2 | #define _UST_TRACEPOINT_H | |
f99be407 PMF |
3 | |
4 | /* | |
1f8b0dff PMF |
5 | * Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
6 | * Copyright (C) 2009 Pierre-Marc Fournier | |
22d72948 | 7 | * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org> |
f99be407 | 8 | * |
8fc2d8db PMF |
9 | * This library is free software; you can redistribute it and/or |
10 | * modify it under the terms of the GNU Lesser General Public | |
f37142a4 MD |
11 | * License as published by the Free Software Foundation; |
12 | * version 2.1 of the License. | |
f99be407 | 13 | * |
8fc2d8db | 14 | * This library is distributed in the hope that it will be useful, |
1f8b0dff | 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
8fc2d8db PMF |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
17 | * Lesser General Public License for more details. | |
1f8b0dff | 18 | * |
8fc2d8db PMF |
19 | * You should have received a copy of the GNU Lesser General Public |
20 | * License along with this library; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
f99be407 PMF |
22 | * |
23 | * Heavily inspired from the Linux Kernel Markers. | |
24 | * | |
1f8b0dff | 25 | * Ported to userspace by Pierre-Marc Fournier. |
f99be407 PMF |
26 | */ |
27 | ||
b7ea1a1c | 28 | #include <urcu-bp.h> |
518d7abb | 29 | #include <ust/core.h> |
b0c4126f | 30 | #include <urcu/list.h> |
f99be407 | 31 | |
f99be407 PMF |
32 | struct tracepoint; |
33 | ||
b979b346 | 34 | struct tracepoint_probe { |
9dec086e NC |
35 | void *func; |
36 | void *data; | |
37 | }; | |
38 | ||
f99be407 PMF |
39 | struct tracepoint { |
40 | const char *name; /* Tracepoint name */ | |
f36c12ab | 41 | char state; /* State. */ |
b979b346 | 42 | struct tracepoint_probe *probes; |
f218ff28 | 43 | }; |
f99be407 | 44 | |
b979b346 | 45 | #define TP_PARAMS(args...) args |
7166e240 PMF |
46 | #define TP_PROTO(args...) args |
47 | #define TP_ARGS(args...) args | |
f99be407 | 48 | |
cc7b66ba MD |
49 | /* |
50 | * Tracepoints should be added to the instrumented code using the | |
51 | * "tracepoint()" macro. | |
52 | */ | |
53 | #define tracepoint(name, args...) __trace_##name(args) | |
54 | ||
55 | #define register_tracepoint(name, probe, data) \ | |
56 | __register_trace_##name(probe, data) | |
57 | ||
58 | #define unregister_tracepoint(name, probe, data) \ | |
59 | __unregister_trace_##name(probe, data) | |
60 | ||
872037bb PMF |
61 | #define CONFIG_TRACEPOINTS |
62 | #ifdef CONFIG_TRACEPOINTS | |
f99be407 PMF |
63 | |
64 | /* | |
65 | * it_func[0] is never NULL because there is at least one element in the array | |
66 | * when the array itself is non NULL. | |
67 | */ | |
68 | #define __DO_TRACE(tp, proto, args) \ | |
69 | do { \ | |
b979b346 MD |
70 | struct tracepoint_probe *__tp_it_probe_ptr; \ |
71 | void *__tp_it_func; \ | |
72 | void *__tp_cb_data; \ | |
f99be407 | 73 | \ |
9dec086e | 74 | rcu_read_lock(); \ |
b979b346 MD |
75 | __tp_it_probe_ptr = rcu_dereference((tp)->probes); \ |
76 | if (__tp_it_probe_ptr) { \ | |
f99be407 | 77 | do { \ |
b979b346 MD |
78 | __tp_it_func = __tp_it_probe_ptr->func; \ |
79 | __tp_cb_data = __tp_it_probe_ptr->data; \ | |
80 | ((void(*)(proto))__tp_it_func)(args); \ | |
81 | } while ((++__tp_it_probe_ptr)->func); \ | |
f99be407 | 82 | } \ |
9dec086e | 83 | rcu_read_unlock(); \ |
f99be407 PMF |
84 | } while (0) |
85 | ||
f36c12ab | 86 | #define __CHECK_TRACE(name, proto, args) \ |
f99be407 | 87 | do { \ |
f36c12ab MD |
88 | if (unlikely(__tracepoint_##name.state)) \ |
89 | __DO_TRACE(&__tracepoint_##name, \ | |
90 | TP_PROTO(proto), TP_ARGS(args)); \ | |
f99be407 PMF |
91 | } while (0) |
92 | ||
93 | /* | |
94 | * Make sure the alignment of the structure in the __tracepoints section will | |
95 | * not add unwanted padding between the beginning of the section and the | |
96 | * structure. Force alignment to the same alignment as the section start. | |
f99be407 | 97 | */ |
8d71973c | 98 | #define __DECLARE_TRACEPOINT(name, proto, args, data_proto, data_args) \ |
f99be407 | 99 | extern struct tracepoint __tracepoint_##name; \ |
cc7b66ba | 100 | static inline void __trace_##name(proto) \ |
f99be407 | 101 | { \ |
f36c12ab | 102 | __CHECK_TRACE(name, TP_PROTO(data_proto), \ |
9dec086e | 103 | TP_ARGS(data_args)); \ |
f99be407 | 104 | } \ |
9dec086e | 105 | static inline int \ |
cc7b66ba | 106 | __register_trace_##name(void (*probe)(data_proto), void *data) \ |
f99be407 | 107 | { \ |
9dec086e NC |
108 | return tracepoint_probe_register(#name, (void *)probe, \ |
109 | data); \ | |
110 | \ | |
f99be407 | 111 | } \ |
9dec086e | 112 | static inline int \ |
cc7b66ba | 113 | __unregister_trace_##name(void (*probe)(data_proto), void *data)\ |
f99be407 | 114 | { \ |
9dec086e NC |
115 | return tracepoint_probe_unregister(#name, (void *)probe, \ |
116 | data); \ | |
f99be407 PMF |
117 | } |
118 | ||
332b3a18 MD |
119 | /* |
120 | * __tracepoints_ptrs section is not const (read-only) to let the linker update | |
121 | * the pointer, allowing PIC code. | |
122 | */ | |
8d71973c | 123 | #define DEFINE_TRACEPOINT_FN(name, reg, unreg) \ |
f99be407 PMF |
124 | static const char __tpstrtab_##name[] \ |
125 | __attribute__((section("__tracepoints_strings"))) = #name; \ | |
126 | struct tracepoint __tracepoint_##name \ | |
f218ff28 MD |
127 | __attribute__((section("__tracepoints"))) = \ |
128 | { __tpstrtab_##name, 0, NULL }; \ | |
332b3a18 | 129 | static struct tracepoint * __tracepoint_ptr_##name \ |
f218ff28 MD |
130 | __attribute__((used, section("__tracepoints_ptrs"))) = \ |
131 | &__tracepoint_##name; | |
f99be407 | 132 | |
8d71973c MD |
133 | #define DEFINE_TRACEPOINT(name) \ |
134 | DEFINE_TRACEPOINT_FN(name, NULL, NULL) | |
9dec086e | 135 | |
f218ff28 MD |
136 | extern void tracepoint_update_probe_range(struct tracepoint * const *begin, |
137 | struct tracepoint * const *end); | |
f99be407 | 138 | |
872037bb | 139 | #else /* !CONFIG_TRACEPOINTS */ |
8d71973c | 140 | #define __DECLARE_TRACEPOINT(name, proto, args) \ |
872037bb PMF |
141 | static inline void trace_##name(proto) \ |
142 | { } \ | |
143 | static inline void _trace_##name(proto) \ | |
144 | { } \ | |
cc7b66ba | 145 | static inline int __register_trace_##name(void (*probe)(proto), void *data) \ |
872037bb PMF |
146 | { \ |
147 | return -ENOSYS; \ | |
148 | } \ | |
cc7b66ba | 149 | static inline int __unregister_trace_##name(void (*probe)(proto), void *data) \ |
872037bb PMF |
150 | { \ |
151 | return -ENOSYS; \ | |
152 | } | |
153 | ||
8d71973c | 154 | #define DEFINE_TRACEPOINT(name) |
872037bb PMF |
155 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) |
156 | #define EXPORT_TRACEPOINT_SYMBOL(name) | |
157 | ||
158 | static inline void tracepoint_update_probe_range(struct tracepoint *begin, | |
159 | struct tracepoint *end) | |
160 | { } | |
161 | #endif /* CONFIG_TRACEPOINTS */ | |
f99be407 | 162 | |
377d33ed | 163 | /* |
8d71973c | 164 | * The need for the DECLARE_TRACEPOINT_NOARGS() is to handle the prototype |
377d33ed | 165 | * (void). "void" is a special value in a function prototype and can |
8d71973c | 166 | * not be combined with other arguments. Since the DECLARE_TRACEPOINT() |
377d33ed MD |
167 | * macro adds a data element at the beginning of the prototype, |
168 | * we need a way to differentiate "(void *data, proto)" from | |
169 | * "(void *data, void)". The second prototype is invalid. | |
170 | * | |
8d71973c | 171 | * DECLARE_TRACEPOINT_NOARGS() passes "void" as the tracepoint prototype |
b979b346 | 172 | * and "void *__tp_cb_data" as the callback prototype. |
377d33ed | 173 | * |
8d71973c | 174 | * DECLARE_TRACEPOINT() passes "proto" as the tracepoint protoype and |
b979b346 | 175 | * "void *__tp_cb_data, proto" as the callback prototype. |
377d33ed | 176 | */ |
8d71973c MD |
177 | #define DECLARE_TRACEPOINT_NOARGS(name) \ |
178 | __DECLARE_TRACEPOINT(name, void, , void *__tp_cb_data, __tp_cb_data) | |
377d33ed | 179 | |
8d71973c MD |
180 | #define DECLARE_TRACEPOINT(name, proto, args) \ |
181 | __DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args),\ | |
b979b346 MD |
182 | TP_PARAMS(void *__tp_cb_data, proto), \ |
183 | TP_PARAMS(__tp_cb_data, args)) | |
9dec086e | 184 | |
f99be407 PMF |
185 | /* |
186 | * Connect a probe to a tracepoint. | |
187 | * Internal API, should not be used directly. | |
188 | */ | |
9dec086e | 189 | extern int tracepoint_probe_register(const char *name, void *probe, void *data); |
f99be407 PMF |
190 | |
191 | /* | |
192 | * Disconnect a probe from a tracepoint. | |
193 | * Internal API, should not be used directly. | |
194 | */ | |
9dec086e | 195 | extern int tracepoint_probe_unregister(const char *name, void *probe, void *data); |
f99be407 | 196 | |
9dec086e NC |
197 | extern int tracepoint_probe_register_noupdate(const char *name, void *probe, |
198 | void *data); | |
199 | extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe, | |
200 | void *data); | |
f99be407 PMF |
201 | extern void tracepoint_probe_update_all(void); |
202 | ||
203 | struct tracepoint_iter { | |
474d745f | 204 | struct tracepoint_lib *lib; |
f218ff28 | 205 | struct tracepoint * const *tracepoint; |
f99be407 PMF |
206 | }; |
207 | ||
208 | extern void tracepoint_iter_start(struct tracepoint_iter *iter); | |
209 | extern void tracepoint_iter_next(struct tracepoint_iter *iter); | |
210 | extern void tracepoint_iter_stop(struct tracepoint_iter *iter); | |
211 | extern void tracepoint_iter_reset(struct tracepoint_iter *iter); | |
f218ff28 MD |
212 | extern int tracepoint_get_iter_range(struct tracepoint * const **tracepoint, |
213 | struct tracepoint * const *begin, struct tracepoint * const *end); | |
f99be407 PMF |
214 | |
215 | /* | |
216 | * tracepoint_synchronize_unregister must be called between the last tracepoint | |
217 | * probe unregistration and the end of module exit to make sure there is no | |
218 | * caller executing a probe when it is freed. | |
219 | */ | |
220 | static inline void tracepoint_synchronize_unregister(void) | |
221 | { | |
270c6b98 | 222 | //ust// synchronize_sched(); |
f99be407 PMF |
223 | } |
224 | ||
474d745f | 225 | struct tracepoint_lib { |
f218ff28 | 226 | struct tracepoint * const *tracepoints_start; |
474d745f | 227 | int tracepoints_count; |
0222e121 | 228 | struct cds_list_head list; |
474d745f PMF |
229 | }; |
230 | ||
f218ff28 | 231 | extern int tracepoint_register_lib(struct tracepoint * const *tracepoints_start, |
872037bb | 232 | int tracepoints_count); |
f218ff28 | 233 | extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); |
872037bb PMF |
234 | |
235 | #define TRACEPOINT_LIB \ | |
bf5fe926 MD |
236 | extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \ |
237 | extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \ | |
332b3a18 MD |
238 | static struct tracepoint * __tracepoint_ptr_dummy \ |
239 | __attribute__((used, section("__tracepoints_ptrs"))); \ | |
bf5fe926 MD |
240 | static void __attribute__((constructor)) __tracepoints__init(void) \ |
241 | { \ | |
103fffbc MD |
242 | tracepoint_register_lib(__start___tracepoints_ptrs, \ |
243 | __stop___tracepoints_ptrs - \ | |
244 | __start___tracepoints_ptrs); \ | |
bf5fe926 MD |
245 | } \ |
246 | \ | |
247 | static void __attribute__((destructor)) __tracepoints__destroy(void) \ | |
248 | { \ | |
103fffbc | 249 | tracepoint_unregister_lib(__start___tracepoints_ptrs); \ |
872037bb PMF |
250 | } |
251 | ||
22d72948 | 252 | |
8d71973c | 253 | #ifndef TRACEPOINT_EVENT |
22d72948 | 254 | /* |
8d71973c | 255 | * For use with the TRACEPOINT_EVENT macro: |
22d72948 NC |
256 | * |
257 | * We define a tracepoint, its arguments, its printf format | |
258 | * and its 'fast binary record' layout. | |
259 | * | |
8d71973c | 260 | * Firstly, name your tracepoint via TRACEPOINT_EVENT(name : the |
22d72948 NC |
261 | * 'subsystem_event' notation is fine. |
262 | * | |
263 | * Think about this whole construct as the | |
264 | * 'trace_sched_switch() function' from now on. | |
265 | * | |
266 | * | |
8d71973c | 267 | * TRACEPOINT_EVENT(sched_switch, |
22d72948 NC |
268 | * |
269 | * * | |
270 | * * A function has a regular function arguments | |
271 | * * prototype, declare it via TP_PROTO(): | |
272 | * * | |
273 | * | |
274 | * TP_PROTO(struct rq *rq, struct task_struct *prev, | |
275 | * struct task_struct *next), | |
276 | * | |
277 | * * | |
278 | * * Define the call signature of the 'function'. | |
279 | * * (Design sidenote: we use this instead of a | |
280 | * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.) | |
281 | * * | |
282 | * | |
283 | * TP_ARGS(rq, prev, next), | |
284 | * | |
285 | * * | |
286 | * * Fast binary tracing: define the trace record via | |
287 | * * TP_STRUCT__entry(). You can think about it like a | |
288 | * * regular C structure local variable definition. | |
289 | * * | |
290 | * * This is how the trace record is structured and will | |
291 | * * be saved into the ring buffer. These are the fields | |
292 | * * that will be exposed to readers. | |
293 | * * | |
294 | * * The declared 'local variable' is called '__entry' | |
295 | * * | |
296 | * * __field(pid_t, prev_prid) is equivalent to a standard declariton: | |
297 | * * | |
298 | * * pid_t prev_pid; | |
299 | * * | |
300 | * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to: | |
301 | * * | |
302 | * * char prev_comm[TASK_COMM_LEN]; | |
303 | * * | |
304 | * | |
305 | * TP_STRUCT__entry( | |
306 | * __array( char, prev_comm, TASK_COMM_LEN ) | |
307 | * __field( pid_t, prev_pid ) | |
308 | * __field( int, prev_prio ) | |
309 | * __array( char, next_comm, TASK_COMM_LEN ) | |
310 | * __field( pid_t, next_pid ) | |
311 | * __field( int, next_prio ) | |
312 | * ), | |
313 | * | |
314 | * * | |
315 | * * Assign the entry into the trace record, by embedding | |
316 | * * a full C statement block into TP_fast_assign(). You | |
317 | * * can refer to the trace record as '__entry' - | |
318 | * * otherwise you can put arbitrary C code in here. | |
319 | * * | |
320 | * * Note: this C code will execute every time a trace event | |
321 | * * happens, on an active tracepoint. | |
322 | * * | |
323 | * | |
324 | * TP_fast_assign( | |
325 | * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); | |
326 | * __entry->prev_pid = prev->pid; | |
327 | * __entry->prev_prio = prev->prio; | |
328 | * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); | |
329 | * __entry->next_pid = next->pid; | |
330 | * __entry->next_prio = next->prio; | |
331 | * ) | |
332 | * | |
333 | * * | |
334 | * * Formatted output of a trace record via TP_printf(). | |
335 | * * This is how the tracepoint will appear under debugging | |
336 | * * of tracepoints. | |
337 | * * | |
338 | * * (raw-binary tracing wont actually perform this step.) | |
339 | * * | |
340 | * | |
341 | * TP_printf("task %s:%d [%d] ==> %s:%d [%d]", | |
342 | * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio, | |
343 | * __entry->next_comm, __entry->next_pid, __entry->next_prio), | |
344 | * | |
345 | * ); | |
346 | * | |
347 | * This macro construct is thus used for the regular printf format | |
348 | * tracing setup. | |
349 | * | |
350 | * A set of (un)registration functions can be passed to the variant | |
8d71973c | 351 | * TRACEPOINT_EVENT_FN to perform any (un)registration work. |
22d72948 NC |
352 | */ |
353 | ||
0c0686ee NC |
354 | struct trace_event { |
355 | const char *name; | |
356 | int (*regfunc)(void *data); | |
357 | int (*unregfunc)(void *data); | |
fc1caebc | 358 | }; |
0c0686ee NC |
359 | |
360 | struct trace_event_lib { | |
fc1caebc | 361 | struct trace_event * const *trace_events_start; |
0c0686ee | 362 | int trace_events_count; |
0222e121 | 363 | struct cds_list_head list; |
0c0686ee NC |
364 | }; |
365 | ||
366 | struct trace_event_iter { | |
367 | struct trace_event_lib *lib; | |
fc1caebc | 368 | struct trace_event * const *trace_event; |
0c0686ee NC |
369 | }; |
370 | ||
371 | extern void lock_trace_events(void); | |
372 | extern void unlock_trace_events(void); | |
373 | ||
374 | extern void trace_event_iter_start(struct trace_event_iter *iter); | |
375 | extern void trace_event_iter_next(struct trace_event_iter *iter); | |
376 | extern void trace_event_iter_reset(struct trace_event_iter *iter); | |
377 | ||
fc1caebc MD |
378 | extern int trace_event_get_iter_range(struct trace_event * const **trace_event, |
379 | struct trace_event * const *begin, | |
380 | struct trace_event * const *end); | |
0c0686ee NC |
381 | |
382 | extern void trace_event_update_process(void); | |
383 | extern int is_trace_event_enabled(const char *channel, const char *name); | |
384 | ||
fc1caebc | 385 | extern int trace_event_register_lib(struct trace_event * const *start_trace_events, |
0c0686ee NC |
386 | int trace_event_count); |
387 | ||
fc1caebc | 388 | extern int trace_event_unregister_lib(struct trace_event * const *start_trace_events); |
0c0686ee | 389 | |
8d71973c | 390 | #define TRACEPOINT_EVENT_LIB \ |
fc1caebc | 391 | extern struct trace_event * const __start___trace_events_ptrs[] \ |
0c0686ee | 392 | __attribute__((weak, visibility("hidden"))); \ |
fc1caebc | 393 | extern struct trace_event * const __stop___trace_events_ptrs[] \ |
0c0686ee | 394 | __attribute__((weak, visibility("hidden"))); \ |
332b3a18 MD |
395 | static struct trace_event * __event_ptrs_dummy \ |
396 | __attribute__((used, section("__trace_events_ptrs"))); \ | |
0c0686ee NC |
397 | static void __attribute__((constructor)) \ |
398 | __trace_events__init(void) \ | |
399 | { \ | |
fc1caebc MD |
400 | trace_event_register_lib(__start___trace_events_ptrs, \ |
401 | __stop___trace_events_ptrs - \ | |
402 | __start___trace_events_ptrs); \ | |
0c0686ee NC |
403 | } \ |
404 | \ | |
405 | static void __attribute__((destructor)) \ | |
406 | __trace_event__destroy(void) \ | |
407 | { \ | |
fc1caebc | 408 | trace_event_unregister_lib(__start___trace_events_ptrs);\ |
0c0686ee NC |
409 | } |
410 | ||
8d71973c MD |
411 | #define DECLARE_TRACEPOINT_EVENT_CLASS(name, proto, args, tstruct, assign, print) |
412 | #define DEFINE_TRACEPOINT_EVENT(template, name, proto, args) \ | |
413 | DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args)) | |
414 | #define DEFINE_TRACEPOINT_EVENT_PRINT(template, name, proto, args, print)\ | |
415 | DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args)) | |
22d72948 | 416 | |
8d71973c MD |
417 | #define TRACEPOINT_EVENT(name, proto, args, struct, assign, print) \ |
418 | DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args)) | |
419 | #define TRACEPOINT_EVENT_FN(name, proto, args, struct, \ | |
22d72948 | 420 | assign, print, reg, unreg) \ |
8d71973c | 421 | DECLARE_TRACEPOINT(name, TP_PARAMS(proto), TP_PARAMS(args)) |
22d72948 | 422 | |
8d71973c | 423 | #endif /* ifdef TRACEPOINT_EVENT (see note above) */ |
22d72948 NC |
424 | |
425 | ||
27b052e3 | 426 | #endif /* _UST_TRACEPOINT_H */ |