ec1a4fce76bf55ec6cb1085688dcd7a0e4a1622c
1 #ifndef _UST_TRACEPOINT_H
2 #define _UST_TRACEPOINT_H
5 * Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
6 * Copyright (C) 2009 Pierre-Marc Fournier
7 * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
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
23 * Heavily inspired from the Linux Kernel Markers.
25 * Ported to userspace by Pierre-Marc Fournier.
40 const char *name
; /* Tracepoint name */
41 char state
; /* State. */
45 #define PARAMS(args...) args
47 #define TP_PROTO(args...) args
48 #define TP_ARGS(args...) args
51 * Tracepoints should be added to the instrumented code using the
52 * "tracepoint()" macro.
54 #define tracepoint(name, args...) __trace_##name(args)
56 #define register_tracepoint(name, probe, data) \
57 __register_trace_##name(probe, data)
59 #define unregister_tracepoint(name, probe, data) \
60 __unregister_trace_##name(probe, data)
62 #define CONFIG_TRACEPOINTS
63 #ifdef CONFIG_TRACEPOINTS
66 * it_func[0] is never NULL because there is at least one element in the array
67 * when the array itself is non NULL.
69 #define __DO_TRACE(tp, proto, args) \
71 struct probe *it_probe_ptr; \
76 it_probe_ptr = rcu_dereference((tp)->probes); \
79 it_func = (it_probe_ptr)->func; \
80 __data = (it_probe_ptr)->data; \
81 ((void(*)(proto))(it_func))(args); \
82 } while ((++it_probe_ptr)->func); \
87 #define __CHECK_TRACE(name, proto, args) \
89 if (unlikely(__tracepoint_##name.state)) \
90 __DO_TRACE(&__tracepoint_##name, \
91 TP_PROTO(proto), TP_ARGS(args)); \
95 * Make sure the alignment of the structure in the __tracepoints section will
96 * not add unwanted padding between the beginning of the section and the
97 * structure. Force alignment to the same alignment as the section start.
99 #define __DECLARE_TRACE(name, proto, args, data_proto, data_args) \
100 extern struct tracepoint __tracepoint_##name; \
101 static inline void __trace_##name(proto) \
103 __CHECK_TRACE(name, TP_PROTO(data_proto), \
104 TP_ARGS(data_args)); \
107 __register_trace_##name(void (*probe)(data_proto), void *data) \
109 return tracepoint_probe_register(#name, (void *)probe, \
114 __unregister_trace_##name(void (*probe)(data_proto), void *data)\
116 return tracepoint_probe_unregister(#name, (void *)probe, \
120 #define DEFINE_TRACE_FN(name, reg, unreg) \
121 static const char __tpstrtab_##name[] \
122 __attribute__((section("__tracepoints_strings"))) = #name; \
123 struct tracepoint __tracepoint_##name \
124 __attribute__((section("__tracepoints"))) = \
125 { __tpstrtab_##name, 0, NULL }; \
126 static struct tracepoint * const __tracepoint_ptr_##name \
127 __attribute__((used, section("__tracepoints_ptrs"))) = \
128 &__tracepoint_##name;
130 #define DEFINE_TRACE(name) \
131 DEFINE_TRACE_FN(name, NULL, NULL)
133 extern void tracepoint_update_probe_range(struct tracepoint
* const *begin
,
134 struct tracepoint
* const *end
);
136 #else /* !CONFIG_TRACEPOINTS */
137 #define __DECLARE_TRACE(name, proto, args) \
138 static inline void trace_##name(proto) \
140 static inline void _trace_##name(proto) \
142 static inline int __register_trace_##name(void (*probe)(proto), void *data) \
146 static inline int __unregister_trace_##name(void (*probe)(proto), void *data) \
151 #define DEFINE_TRACE(name)
152 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
153 #define EXPORT_TRACEPOINT_SYMBOL(name)
155 static inline void tracepoint_update_probe_range(struct tracepoint
*begin
,
156 struct tracepoint
*end
)
158 #endif /* CONFIG_TRACEPOINTS */
161 * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
162 * (void). "void" is a special value in a function prototype and can
163 * not be combined with other arguments. Since the DECLARE_TRACE()
164 * macro adds a data element at the beginning of the prototype,
165 * we need a way to differentiate "(void *data, proto)" from
166 * "(void *data, void)". The second prototype is invalid.
168 * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
169 * and "void *__data" as the callback prototype.
171 * DECLARE_TRACE() passes "proto" as the tracepoint protoype and
172 * "void *__data, proto" as the callback prototype.
174 #define DECLARE_TRACE_NOARGS(name) \
175 __DECLARE_TRACE(name, void, , void *__data, __data)
177 #define DECLARE_TRACE(name, proto, args) \
178 __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
179 PARAMS(void *__data, proto), \
180 PARAMS(__data, args))
183 * Connect a probe to a tracepoint.
184 * Internal API, should not be used directly.
186 extern int tracepoint_probe_register(const char *name
, void *probe
, void *data
);
189 * Disconnect a probe from a tracepoint.
190 * Internal API, should not be used directly.
192 extern int tracepoint_probe_unregister(const char *name
, void *probe
, void *data
);
194 extern int tracepoint_probe_register_noupdate(const char *name
, void *probe
,
196 extern int tracepoint_probe_unregister_noupdate(const char *name
, void *probe
,
198 extern void tracepoint_probe_update_all(void);
200 struct tracepoint_iter
{
201 struct tracepoint_lib
*lib
;
202 struct tracepoint
* const *tracepoint
;
205 extern void tracepoint_iter_start(struct tracepoint_iter
*iter
);
206 extern void tracepoint_iter_next(struct tracepoint_iter
*iter
);
207 extern void tracepoint_iter_stop(struct tracepoint_iter
*iter
);
208 extern void tracepoint_iter_reset(struct tracepoint_iter
*iter
);
209 extern int tracepoint_get_iter_range(struct tracepoint
* const **tracepoint
,
210 struct tracepoint
* const *begin
, struct tracepoint
* const *end
);
213 * tracepoint_synchronize_unregister must be called between the last tracepoint
214 * probe unregistration and the end of module exit to make sure there is no
215 * caller executing a probe when it is freed.
217 static inline void tracepoint_synchronize_unregister(void)
219 //ust// synchronize_sched();
222 struct tracepoint_lib
{
223 struct tracepoint
* const *tracepoints_start
;
224 int tracepoints_count
;
225 struct cds_list_head list
;
228 extern int tracepoint_register_lib(struct tracepoint
* const *tracepoints_start
,
229 int tracepoints_count
);
230 extern int tracepoint_unregister_lib(struct tracepoint
* const *tracepoints_start
);
232 #define TRACEPOINT_LIB \
233 extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
234 extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
235 static struct tracepoint * const __tracepoint_ptr_dummy \
236 __attribute__((used, section("__tracepoints_ptrs"))) = NULL; \
237 static void __attribute__((constructor)) __tracepoints__init(void) \
239 tracepoint_register_lib(__start___tracepoints_ptrs, \
240 __stop___tracepoints_ptrs - \
241 __start___tracepoints_ptrs); \
244 static void __attribute__((destructor)) __tracepoints__destroy(void) \
246 tracepoint_unregister_lib(__start___tracepoints_ptrs); \
252 * For use with the TRACE_EVENT macro:
254 * We define a tracepoint, its arguments, its printf format
255 * and its 'fast binary record' layout.
257 * Firstly, name your tracepoint via TRACE_EVENT(name : the
258 * 'subsystem_event' notation is fine.
260 * Think about this whole construct as the
261 * 'trace_sched_switch() function' from now on.
264 * TRACE_EVENT(sched_switch,
267 * * A function has a regular function arguments
268 * * prototype, declare it via TP_PROTO():
271 * TP_PROTO(struct rq *rq, struct task_struct *prev,
272 * struct task_struct *next),
275 * * Define the call signature of the 'function'.
276 * * (Design sidenote: we use this instead of a
277 * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
280 * TP_ARGS(rq, prev, next),
283 * * Fast binary tracing: define the trace record via
284 * * TP_STRUCT__entry(). You can think about it like a
285 * * regular C structure local variable definition.
287 * * This is how the trace record is structured and will
288 * * be saved into the ring buffer. These are the fields
289 * * that will be exposed to readers.
291 * * The declared 'local variable' is called '__entry'
293 * * __field(pid_t, prev_prid) is equivalent to a standard declariton:
297 * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
299 * * char prev_comm[TASK_COMM_LEN];
303 * __array( char, prev_comm, TASK_COMM_LEN )
304 * __field( pid_t, prev_pid )
305 * __field( int, prev_prio )
306 * __array( char, next_comm, TASK_COMM_LEN )
307 * __field( pid_t, next_pid )
308 * __field( int, next_prio )
312 * * Assign the entry into the trace record, by embedding
313 * * a full C statement block into TP_fast_assign(). You
314 * * can refer to the trace record as '__entry' -
315 * * otherwise you can put arbitrary C code in here.
317 * * Note: this C code will execute every time a trace event
318 * * happens, on an active tracepoint.
322 * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
323 * __entry->prev_pid = prev->pid;
324 * __entry->prev_prio = prev->prio;
325 * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
326 * __entry->next_pid = next->pid;
327 * __entry->next_prio = next->prio;
331 * * Formatted output of a trace record via TP_printf().
332 * * This is how the tracepoint will appear under debugging
335 * * (raw-binary tracing wont actually perform this step.)
338 * TP_printf("task %s:%d [%d] ==> %s:%d [%d]",
339 * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
340 * __entry->next_comm, __entry->next_pid, __entry->next_prio),
344 * This macro construct is thus used for the regular printf format
347 * A set of (un)registration functions can be passed to the variant
348 * TRACE_EVENT_FN to perform any (un)registration work.
353 int (*regfunc
)(void *data
);
354 int (*unregfunc
)(void *data
);
357 struct trace_event_lib
{
358 struct trace_event
* const *trace_events_start
;
359 int trace_events_count
;
360 struct cds_list_head list
;
363 struct trace_event_iter
{
364 struct trace_event_lib
*lib
;
365 struct trace_event
* const *trace_event
;
368 extern void lock_trace_events(void);
369 extern void unlock_trace_events(void);
371 extern void trace_event_iter_start(struct trace_event_iter
*iter
);
372 extern void trace_event_iter_next(struct trace_event_iter
*iter
);
373 extern void trace_event_iter_reset(struct trace_event_iter
*iter
);
375 extern int trace_event_get_iter_range(struct trace_event
* const **trace_event
,
376 struct trace_event
* const *begin
,
377 struct trace_event
* const *end
);
379 extern void trace_event_update_process(void);
380 extern int is_trace_event_enabled(const char *channel
, const char *name
);
382 extern int trace_event_register_lib(struct trace_event
* const *start_trace_events
,
383 int trace_event_count
);
385 extern int trace_event_unregister_lib(struct trace_event
* const *start_trace_events
);
387 #define TRACE_EVENT_LIB \
388 extern struct trace_event * const __start___trace_events_ptrs[] \
389 __attribute__((weak, visibility("hidden"))); \
390 extern struct trace_event * const __stop___trace_events_ptrs[] \
391 __attribute__((weak, visibility("hidden"))); \
392 static struct trace_event * const __event_ptrs_dummy \
393 __attribute__((used, section("__trace_events_ptrs"))) = NULL; \
394 static void __attribute__((constructor)) \
395 __trace_events__init(void) \
397 trace_event_register_lib(__start___trace_events_ptrs, \
398 __stop___trace_events_ptrs - \
399 __start___trace_events_ptrs); \
402 static void __attribute__((destructor)) \
403 __trace_event__destroy(void) \
405 trace_event_unregister_lib(__start___trace_events_ptrs);\
408 #define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
409 #define DEFINE_TRACE_EVENT(template, name, proto, args) \
410 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
411 #define DEFINE_TRACE_EVENT_PRINT(template, name, proto, args, print) \
412 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
414 #define TRACE_EVENT(name, proto, args, struct, assign, print) \
415 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
416 #define TRACE_EVENT_FN(name, proto, args, struct, \
417 assign, print, reg, unreg) \
418 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
420 #endif /* ifdef TRACE_EVENT (see note above) */
423 #endif /* _UST_TRACEPOINT_H */
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