1 #ifndef _LTTNG_TRACEPOINT_H
2 #define _LTTNG_TRACEPOINT_H
5 * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
17 #include <lttng/tracepoint-types.h>
18 #include <lttng/tracepoint-rcu.h>
19 #include <urcu/compiler.h>
20 #include <dlfcn.h> /* for dlopen */
21 #include <string.h> /* for memset */
23 #include <lttng/ust-config.h> /* for sdt */
25 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
26 #define SDT_USE_VARIADIC
29 #define STAP_PROBEV(...)
36 #define tracepoint(provider, name, ...) \
38 STAP_PROBEV(provider, name, ## __VA_ARGS__); \
39 if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
40 __tracepoint_cb_##provider##___##name(__VA_ARGS__); \
43 #define TP_ARGS(...) __VA_ARGS__
46 * TP_ARGS takes tuples of type, argument separated by a comma.
47 * It can take up to 10 tuples (which means that less than 10 tuples is
49 * Each tuple is also separated by a comma.
51 #define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
53 #define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
54 __TP_COMBINE_TOKENS(_tokena, _tokenb)
55 #define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
56 _tokena##_tokenb##_tokenc
57 #define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
58 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
59 #define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
60 _tokena##_tokenb##_tokenc##_tokend
61 #define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
62 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
64 /* _TP_EXVAR* extract the var names. */
66 #define _TP_EXVAR2(a,b) b
67 #define _TP_EXVAR4(a,b,c,d) b,d
68 #define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
69 #define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
70 #define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
71 #define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
72 #define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
73 #define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) b,d,f,h,j,l,n,p
74 #define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) b,d,f,h,j,l,n,p,r
75 #define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) b,d,f,h,j,l,n,p,r,t
77 #define _TP_EXDATA_VAR0() __tp_data
78 #define _TP_EXDATA_VAR2(a,b) __tp_data,b
79 #define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
80 #define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
81 #define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
82 #define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
83 #define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
84 #define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) __tp_data,b,d,f,h,j,l,n
85 #define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) __tp_data,b,d,f,h,j,l,n,p
86 #define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) __tp_data,b,d,f,h,j,l,n,p,r
87 #define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) __tp_data,b,d,f,h,j,l,n,p,r,t
89 /* _TP_EXPROTO* extract tuples of type, var */
90 #define _TP_EXPROTO0()
91 #define _TP_EXPROTO2(a,b) a b
92 #define _TP_EXPROTO4(a,b,c,d) a b,c d
93 #define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
94 #define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
95 #define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
96 #define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l) a b,c d,e f,g h,i j,k l
97 #define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) a b,c d,e f,g h,i j,k l,m n
98 #define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) a b,c d,e f,g h,i j,k l,m n,o p
99 #define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) a b,c d,e f,g h,i j,k l,m n,o p,q r
100 #define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
102 #define _TP_EXDATA_PROTO0() void *__tp_data
103 #define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
104 #define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
105 #define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
106 #define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
107 #define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j) void *__tp_data,a b,c d,e f,g h,i j
108 #define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l) void *__tp_data,a b,c d,e f,g h,i j,k l
109 #define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) void *__tp_data,a b,c d,e f,g h,i j,k l,m n
110 #define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p
111 #define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
112 #define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
114 /* Preprocessor trick to count arguments. Inspired from sdt.h. */
115 #define _TP_NARGS(...) __TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
116 #define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...) N
117 #define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
118 #define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
119 #define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
120 #define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
121 #define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
122 #define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
123 #define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
124 #define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
125 #define _TP_PARAMS(...) __VA_ARGS__
127 #define _DECLARE_TRACEPOINT(_provider, _name, ...) \
128 extern struct tracepoint __tracepoint_##_provider##___##_name; \
129 static inline void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
131 struct tracepoint_probe *__tp_probe; \
133 if (!TP_RCU_LINK_TEST()) \
135 tp_rcu_read_lock_bp(); \
136 __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
137 if (caa_unlikely(!__tp_probe)) \
140 void *__tp_cb = __tp_probe->func; \
141 void *__tp_data = __tp_probe->data; \
143 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
144 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
145 } while ((++__tp_probe)->func); \
147 tp_rcu_read_unlock_bp(); \
149 static inline void __tracepoint_register_##_provider##___##_name(char *name, \
150 void *func, void *data) \
152 __tracepoint_probe_register(name, func, data); \
154 static inline void __tracepoint_unregister_##_provider##___##_name(char *name, \
155 void *func, void *data) \
157 __tracepoint_probe_unregister(name, func, data); \
160 extern int __tracepoint_probe_register(const char *name
, void *func
, void *data
);
161 extern int __tracepoint_probe_unregister(const char *name
, void *func
, void *data
);
164 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
165 * shared across objects in a module/main executable.
167 struct tracepoint_dlopen
{
168 void *liblttngust_handle
;
170 int (*tracepoint_register_lib
)(struct tracepoint
* const *tracepoints_start
,
171 int tracepoints_count
);
172 int (*tracepoint_unregister_lib
)(struct tracepoint
* const *tracepoints_start
);
174 void (*rcu_read_lock_sym_bp
)(void);
175 void (*rcu_read_unlock_sym_bp
)(void);
176 void *(*rcu_dereference_sym_bp
)(void *p
);
180 extern struct tracepoint_dlopen tracepoint_dlopen
;
182 #ifdef TRACEPOINT_DEFINE
185 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
186 * unresolved symbol that requires the provider to be linked in. When
187 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
188 * unresolved symbol that depends on having the provider linked in,
189 * otherwise the linker complains. This deals with use of static
190 * libraries, ensuring that the linker does not remove the provider
191 * object from the executable.
193 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
194 #define _TRACEPOINT_UNDEFINED_REF(provider) NULL
195 #else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
196 #define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
197 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
200 * Note: to allow PIC code, we need to allow the linker to update the pointers
201 * in the __tracepoints_ptrs section.
202 * Therefore, this section is _not_ const (read-only).
204 #define _TP_EXTRACT_STRING(...) #__VA_ARGS__
206 #define _DEFINE_TRACEPOINT(_provider, _name, _args) \
207 extern int __tracepoint_provider_##_provider; \
208 static const char __tp_strtab_##_provider##___##_name[] \
209 __attribute__((section("__tracepoints_strings"))) = \
210 #_provider ":" #_name; \
211 struct tracepoint __tracepoint_##_provider##___##_name \
212 __attribute__((section("__tracepoints"))) = \
214 __tp_strtab_##_provider##___##_name, \
217 _TRACEPOINT_UNDEFINED_REF(_provider), \
218 _TP_EXTRACT_STRING(_args), \
220 static struct tracepoint * __tracepoint_ptr_##_provider##___##_name \
221 __attribute__((used, section("__tracepoints_ptrs"))) = \
222 &__tracepoint_##_provider##___##_name;
225 * These weak symbols, the constructor, and destructor take care of
226 * registering only _one_ instance of the tracepoints per shared-ojbect
227 * (or for the whole main program).
229 extern struct tracepoint
* const __start___tracepoints_ptrs
[]
230 __attribute__((weak
, visibility("hidden")));
231 extern struct tracepoint
* const __stop___tracepoints_ptrs
[]
232 __attribute__((weak
, visibility("hidden")));
233 int __tracepoint_registered
234 __attribute__((weak
, visibility("hidden")));
235 struct tracepoint_dlopen tracepoint_dlopen
236 __attribute__((weak
, visibility("hidden")));
238 static void __attribute__((constructor
)) __tracepoints__init(void)
240 if (__tracepoint_registered
++)
243 tracepoint_dlopen
.liblttngust_handle
=
244 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW
| RTLD_GLOBAL
);
245 if (!tracepoint_dlopen
.liblttngust_handle
)
247 tracepoint_dlopen
.tracepoint_register_lib
=
248 URCU_FORCE_CAST(int (*)(struct tracepoint
* const *, int),
249 dlsym(tracepoint_dlopen
.liblttngust_handle
,
250 "tracepoint_register_lib"));
251 tracepoint_dlopen
.tracepoint_unregister_lib
=
252 URCU_FORCE_CAST(int (*)(struct tracepoint
* const *),
253 dlsym(tracepoint_dlopen
.liblttngust_handle
,
254 "tracepoint_unregister_lib"));
256 tracepoint_dlopen
.rcu_read_lock_sym_bp
=
257 URCU_FORCE_CAST(void (*)(void),
258 dlsym(tracepoint_dlopen
.liblttngust_handle
,
259 "tp_rcu_read_lock_bp"));
260 tracepoint_dlopen
.rcu_read_unlock_sym_bp
=
261 URCU_FORCE_CAST(void (*)(void),
262 dlsym(tracepoint_dlopen
.liblttngust_handle
,
263 "tp_rcu_read_unlock_bp"));
264 tracepoint_dlopen
.rcu_dereference_sym_bp
=
265 URCU_FORCE_CAST(void *(*)(void *p
),
266 dlsym(tracepoint_dlopen
.liblttngust_handle
,
267 "tp_rcu_dereference_sym_bp"));
269 tracepoint_dlopen
.tracepoint_register_lib(__start___tracepoints_ptrs
,
270 __stop___tracepoints_ptrs
-
271 __start___tracepoints_ptrs
);
274 static void __attribute__((destructor
)) __tracepoints__destroy(void)
278 if (--__tracepoint_registered
)
280 if (tracepoint_dlopen
.tracepoint_unregister_lib
)
281 tracepoint_dlopen
.tracepoint_unregister_lib(__start___tracepoints_ptrs
);
282 if (tracepoint_dlopen
.liblttngust_handle
) {
283 ret
= dlclose(tracepoint_dlopen
.liblttngust_handle
);
285 memset(&tracepoint_dlopen
, 0, sizeof(tracepoint_dlopen
));
289 #else /* TRACEPOINT_DEFINE */
291 #define _DEFINE_TRACEPOINT(_provider, _name, _args)
293 #endif /* #else TRACEPOINT_DEFINE */
299 #endif /* _LTTNG_TRACEPOINT_H */
301 /* The following declarations must be outside re-inclusion protection. */
303 #ifndef TRACEPOINT_EVENT
306 * How to use the TRACEPOINT_EVENT macro:
310 * TRACEPOINT_EVENT(someproject_component, event_name,
312 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
314 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
315 * long *, arg4, size_t, arg4_len),
317 * * TP_FIELDS describes the event payload layout in the trace *
320 * * Integer, printed in base 10 *
321 * ctf_integer(int, field_a, arg0)
323 * * Integer, printed with 0x base 16 *
324 * ctf_integer_hex(unsigned long, field_d, arg1)
326 * * Array Sequence, printed as UTF8-encoded array of bytes *
327 * ctf_array_text(char, field_b, string, FIXED_LEN)
328 * ctf_sequence_text(char, field_c, string, size_t, strlen)
330 * * String, printed as UTF8-encoded string *
331 * ctf_string(field_e, string)
333 * * Array sequence of signed integer values *
334 * ctf_array(long, field_f, arg4, FIXED_LEN4)
335 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
339 * More detailed explanation:
341 * The name of the tracepoint is expressed as a tuple with the provider
342 * and name arguments.
344 * The provider and name should be a proper C99 identifier.
345 * The "provider" and "name" MUST follow these rules to ensure no
346 * namespace clash occurs:
348 * For projects (applications and libraries) for which an entity
349 * specific to the project controls the source code and thus its
350 * tracepoints (typically with a scope larger than a single company):
353 * project_component, event
357 * Where "project" is the name of the project,
358 * "component" is the name of the project component (which may
359 * include several levels of sub-components, e.g.
360 * ...component_subcomponent_...) where the tracepoint is located
362 * "event" is the name of the tracepoint event.
364 * For projects issued from a single company wishing to advertise that
365 * the company controls the source code and thus the tracepoints, the
366 * "com_" prefix should be used:
369 * com_company_project_component, event
371 * com_company_project, event
373 * Where "company" is the name of the company,
374 * "project" is the name of the project,
375 * "component" is the name of the project component (which may
376 * include several levels of sub-components, e.g.
377 * ...component_subcomponent_...) where the tracepoint is located
379 * "event" is the name of the tracepoint event.
381 * the provider:event identifier is limited to 127 characters.
384 #define TRACEPOINT_EVENT(provider, name, args, fields) \
385 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
386 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
388 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
390 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
391 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
392 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
394 #endif /* #ifndef TRACEPOINT_EVENT */
396 #ifndef TRACEPOINT_LOGLEVEL
399 * Tracepoint Loglevels
401 * Typical use of these loglevels:
403 * The loglevels go from 0 to 14. Higher numbers imply the most
404 * verbosity (higher event throughput expected.
406 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
407 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
414 * action must be taken immediately
417 * critical conditions
426 * normal, but significant, condition
429 * informational message
431 * TRACE_DEBUG_SYSTEM 7
432 * debug information with system-level scope (set of programs)
434 * TRACE_DEBUG_PROGRAM 8
435 * debug information with program-level scope (set of processes)
437 * TRACE_DEBUG_PROCESS 9
438 * debug information with process-level scope (set of modules)
440 * TRACE_DEBUG_MODULE 10
441 * debug information with module (executable/library) scope (set of units)
443 * TRACE_DEBUG_UNIT 11
444 * debug information with compilation unit scope (set of functions)
446 * TRACE_DEBUG_FUNCTION 12
447 * debug information with function-level scope
449 * TRACE_DEBUG_LINE 13
450 * debug information with line-level scope (TRACEPOINT_EVENT default)
453 * debug-level message (trace_printf default)
455 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
456 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
457 * tracepoint name. The first field is the provider name, the second
458 * field is the name of the tracepoint, the third field is the loglevel
461 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
464 * The TRACEPOINT_PROVIDER must be already declared before declaring a
465 * TRACEPOINT_LOGLEVEL.
476 TRACE_DEBUG_SYSTEM
= 7,
477 TRACE_DEBUG_PROGRAM
= 8,
478 TRACE_DEBUG_PROCESS
= 9,
479 TRACE_DEBUG_MODULE
= 10,
480 TRACE_DEBUG_UNIT
= 11,
481 TRACE_DEBUG_FUNCTION
= 12,
482 TRACE_DEBUG_LINE
= 13,
486 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
488 #endif /* #ifndef TRACEPOINT_LOGLEVEL */