| 1 | /* |
| 2 | * lttng.h |
| 3 | * |
| 4 | * Linux Trace Toolkit Control Library Header File |
| 5 | * |
| 6 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or modify it |
| 9 | * under the terms of the GNU Lesser General Public License as published by the |
| 10 | * Free Software Foundation; only version 2.1 of the License. |
| 11 | * |
| 12 | * This library is distributed in the hope that it will be useful, but WITHOUT |
| 13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
| 15 | * for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public License |
| 18 | * along with this library; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | #ifndef _LTTNG_H |
| 23 | #define _LTTNG_H |
| 24 | |
| 25 | #include <limits.h> |
| 26 | #include <stdint.h> |
| 27 | #include <sys/types.h> |
| 28 | |
| 29 | /* |
| 30 | * Event symbol length. Copied from LTTng kernel ABI. |
| 31 | */ |
| 32 | #define LTTNG_SYMBOL_NAME_LEN 256 |
| 33 | |
| 34 | /* |
| 35 | * Every lttng_event_* structure both apply to kernel event and user-space |
| 36 | * event. |
| 37 | */ |
| 38 | |
| 39 | /* |
| 40 | * Domain types: the different possible tracers. |
| 41 | */ |
| 42 | enum lttng_domain_type { |
| 43 | LTTNG_DOMAIN_KERNEL = 1, |
| 44 | LTTNG_DOMAIN_UST = 2, |
| 45 | |
| 46 | /* |
| 47 | * For now, the domains below are not implemented. However, we keep them |
| 48 | * here in order to retain their enum values for future development. Note |
| 49 | * that it is on the roadmap to implement them. |
| 50 | * |
| 51 | LTTNG_DOMAIN_UST_EXEC_NAME = 3, |
| 52 | LTTNG_DOMAIN_UST_PID = 4, |
| 53 | LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5, |
| 54 | */ |
| 55 | }; |
| 56 | |
| 57 | /* |
| 58 | * Instrumentation type of tracing event. |
| 59 | */ |
| 60 | enum lttng_event_type { |
| 61 | LTTNG_EVENT_ALL = -1, |
| 62 | LTTNG_EVENT_TRACEPOINT = 0, |
| 63 | LTTNG_EVENT_PROBE = 1, |
| 64 | LTTNG_EVENT_FUNCTION = 2, |
| 65 | LTTNG_EVENT_FUNCTION_ENTRY = 3, |
| 66 | LTTNG_EVENT_NOOP = 4, |
| 67 | LTTNG_EVENT_SYSCALL = 5, |
| 68 | }; |
| 69 | |
| 70 | /* |
| 71 | * Loglevel information. |
| 72 | */ |
| 73 | enum lttng_loglevel_type { |
| 74 | LTTNG_EVENT_LOGLEVEL_ALL = 0, |
| 75 | LTTNG_EVENT_LOGLEVEL_RANGE = 1, |
| 76 | LTTNG_EVENT_LOGLEVEL_SINGLE = 2, |
| 77 | }; |
| 78 | |
| 79 | /* |
| 80 | * LTTng consumer mode |
| 81 | */ |
| 82 | enum lttng_event_output { |
| 83 | LTTNG_EVENT_SPLICE = 0, |
| 84 | LTTNG_EVENT_MMAP = 1, |
| 85 | }; |
| 86 | |
| 87 | /* Event context possible type */ |
| 88 | enum lttng_event_context_type { |
| 89 | LTTNG_EVENT_CONTEXT_PID = 0, |
| 90 | LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1, |
| 91 | LTTNG_EVENT_CONTEXT_PROCNAME = 2, |
| 92 | LTTNG_EVENT_CONTEXT_PRIO = 3, |
| 93 | LTTNG_EVENT_CONTEXT_NICE = 4, |
| 94 | LTTNG_EVENT_CONTEXT_VPID = 5, |
| 95 | LTTNG_EVENT_CONTEXT_TID = 6, |
| 96 | LTTNG_EVENT_CONTEXT_VTID = 7, |
| 97 | LTTNG_EVENT_CONTEXT_PPID = 8, |
| 98 | LTTNG_EVENT_CONTEXT_VPPID = 9, |
| 99 | LTTNG_EVENT_CONTEXT_PTHREAD_ID = 10, |
| 100 | }; |
| 101 | |
| 102 | enum lttng_calibrate_type { |
| 103 | LTTNG_CALIBRATE_FUNCTION = 0, |
| 104 | }; |
| 105 | |
| 106 | #define LTTNG_DOMAIN_PADDING1 16 |
| 107 | #define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32 |
| 108 | struct lttng_domain { |
| 109 | enum lttng_domain_type type; |
| 110 | char padding[LTTNG_DOMAIN_PADDING1]; |
| 111 | |
| 112 | union { |
| 113 | pid_t pid; |
| 114 | char exec_name[NAME_MAX]; |
| 115 | char padding[LTTNG_DOMAIN_PADDING2]; |
| 116 | } attr; |
| 117 | }; |
| 118 | |
| 119 | /* Perf counter attributes */ |
| 120 | #define LTTNG_PERF_EVENT_PADDING1 16 |
| 121 | struct lttng_event_perf_counter_ctx { |
| 122 | uint32_t type; |
| 123 | uint64_t config; |
| 124 | char name[LTTNG_SYMBOL_NAME_LEN]; |
| 125 | |
| 126 | char padding[LTTNG_PERF_EVENT_PADDING1]; |
| 127 | }; |
| 128 | |
| 129 | /* Event/Channel context */ |
| 130 | #define LTTNG_EVENT_CONTEXT_PADDING1 16 |
| 131 | #define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32 |
| 132 | struct lttng_event_context { |
| 133 | enum lttng_event_context_type ctx; |
| 134 | char padding[LTTNG_EVENT_CONTEXT_PADDING1]; |
| 135 | |
| 136 | union { |
| 137 | struct lttng_event_perf_counter_ctx perf_counter; |
| 138 | char padding[LTTNG_EVENT_CONTEXT_PADDING2]; |
| 139 | } u; |
| 140 | }; |
| 141 | |
| 142 | /* |
| 143 | * Event probe. |
| 144 | * |
| 145 | * Either addr is used or symbol_name and offset. |
| 146 | */ |
| 147 | #define LTTNG_EVENT_PROBE_PADDING1 16 |
| 148 | struct lttng_event_probe_attr { |
| 149 | uint64_t addr; |
| 150 | |
| 151 | uint64_t offset; |
| 152 | char symbol_name[LTTNG_SYMBOL_NAME_LEN]; |
| 153 | |
| 154 | char padding[LTTNG_EVENT_PROBE_PADDING1]; |
| 155 | }; |
| 156 | |
| 157 | /* |
| 158 | * Function tracer |
| 159 | */ |
| 160 | #define LTTNG_EVENT_FUNCTION_PADDING1 16 |
| 161 | struct lttng_event_function_attr { |
| 162 | char symbol_name[LTTNG_SYMBOL_NAME_LEN]; |
| 163 | |
| 164 | char padding[LTTNG_EVENT_FUNCTION_PADDING1]; |
| 165 | }; |
| 166 | |
| 167 | /* |
| 168 | * Generic lttng event |
| 169 | */ |
| 170 | #define LTTNG_EVENT_PADDING1 16 |
| 171 | #define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32 |
| 172 | struct lttng_event { |
| 173 | enum lttng_event_type type; |
| 174 | char name[LTTNG_SYMBOL_NAME_LEN]; |
| 175 | |
| 176 | enum lttng_loglevel_type loglevel_type; |
| 177 | int loglevel; |
| 178 | |
| 179 | uint32_t enabled; |
| 180 | pid_t pid; |
| 181 | |
| 182 | char padding[LTTNG_EVENT_PADDING1]; |
| 183 | |
| 184 | /* Per event type configuration */ |
| 185 | union { |
| 186 | struct lttng_event_probe_attr probe; |
| 187 | struct lttng_event_function_attr ftrace; |
| 188 | |
| 189 | char padding[LTTNG_EVENT_PADDING2]; |
| 190 | } attr; |
| 191 | }; |
| 192 | |
| 193 | /* |
| 194 | * Tracer channel attributes. For both kernel and user-space. |
| 195 | */ |
| 196 | #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32 |
| 197 | struct lttng_channel_attr { |
| 198 | int overwrite; /* 1: overwrite, 0: discard */ |
| 199 | uint64_t subbuf_size; /* bytes */ |
| 200 | uint64_t num_subbuf; /* power of 2 */ |
| 201 | unsigned int switch_timer_interval; /* usec */ |
| 202 | unsigned int read_timer_interval; /* usec */ |
| 203 | enum lttng_event_output output; /* splice, mmap */ |
| 204 | |
| 205 | char padding[LTTNG_CHANNEL_ATTR_PADDING1]; |
| 206 | }; |
| 207 | |
| 208 | /* |
| 209 | * Channel information structure. For both kernel and user-space. |
| 210 | */ |
| 211 | #define LTTNG_CHANNEL_PADDING1 16 |
| 212 | struct lttng_channel { |
| 213 | char name[LTTNG_SYMBOL_NAME_LEN]; |
| 214 | uint32_t enabled; |
| 215 | struct lttng_channel_attr attr; |
| 216 | |
| 217 | char padding[LTTNG_CHANNEL_PADDING1]; |
| 218 | }; |
| 219 | |
| 220 | #define LTTNG_CALIBRATE_PADDING1 16 |
| 221 | struct lttng_calibrate { |
| 222 | enum lttng_calibrate_type type; |
| 223 | |
| 224 | char padding[LTTNG_CALIBRATE_PADDING1]; |
| 225 | }; |
| 226 | |
| 227 | /* |
| 228 | * Basic session information. |
| 229 | * |
| 230 | * This is an 'output data' meaning that it only comes *from* the session |
| 231 | * daemon *to* the lttng client. It's basically a 'human' representation of |
| 232 | * tracing entities (here a session). |
| 233 | */ |
| 234 | #define LTTNG_SESSION_PADDING1 16 |
| 235 | struct lttng_session { |
| 236 | char name[NAME_MAX]; |
| 237 | /* The path where traces are written */ |
| 238 | char path[PATH_MAX]; |
| 239 | uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */ |
| 240 | |
| 241 | char padding[LTTNG_SESSION_PADDING1]; |
| 242 | }; |
| 243 | |
| 244 | /* |
| 245 | * Handle used as a context for commands. |
| 246 | */ |
| 247 | #define LTTNG_HANDLE_PADDING1 16 |
| 248 | struct lttng_handle { |
| 249 | char session_name[NAME_MAX]; |
| 250 | struct lttng_domain domain; |
| 251 | |
| 252 | char padding[LTTNG_HANDLE_PADDING1]; |
| 253 | }; |
| 254 | |
| 255 | /* |
| 256 | * Public LTTng control API |
| 257 | * |
| 258 | * For functions having an lttng domain type as parameter, if a bad value is |
| 259 | * given, NO default is applied and an error is returned. |
| 260 | * |
| 261 | * On success, all functions of the API return 0 or the size of the allocated |
| 262 | * array (in bytes). |
| 263 | * |
| 264 | * On error, a negative value is returned being a specific lttng-tools error |
| 265 | * code which can be humanly interpreted with lttng_strerror(err). |
| 266 | * |
| 267 | * Exceptions to this are noted below. |
| 268 | */ |
| 269 | |
| 270 | /* |
| 271 | * Create a handle used as a context for every request made to the library. |
| 272 | * |
| 273 | * This handle contains the session name and lttng domain on which the command |
| 274 | * will be executed. |
| 275 | * The returned pointer will be NULL in case of malloc() error. |
| 276 | */ |
| 277 | extern struct lttng_handle *lttng_create_handle(const char *session_name, |
| 278 | struct lttng_domain *domain); |
| 279 | |
| 280 | /* |
| 281 | * Destroy a handle. This will simply free(3) the data pointer returned by |
| 282 | * lttng_create_handle(), rendering it unusable. |
| 283 | */ |
| 284 | extern void lttng_destroy_handle(struct lttng_handle *handle); |
| 285 | |
| 286 | /* |
| 287 | * Create a tracing session using a name and a path where the trace will be |
| 288 | * written. |
| 289 | */ |
| 290 | extern int lttng_create_session(const char *name, const char *path); |
| 291 | |
| 292 | /* |
| 293 | * Destroy a tracing session. |
| 294 | * |
| 295 | * The session will not be usable anymore, tracing will be stopped for all |
| 296 | * registered traces, and the tracing buffers will be flushed. |
| 297 | */ |
| 298 | extern int lttng_destroy_session(const char *name); |
| 299 | |
| 300 | /* |
| 301 | * List all the tracing sessions. |
| 302 | * |
| 303 | * Return the size (number of entries) of the "lttng_session" array. Caller |
| 304 | * must free(3). |
| 305 | */ |
| 306 | extern int lttng_list_sessions(struct lttng_session **sessions); |
| 307 | |
| 308 | /* |
| 309 | * List the registered domain(s) of a session. |
| 310 | * |
| 311 | * Return the size (number of entries) of the "lttng_domain" array. Caller |
| 312 | * must free(3). |
| 313 | */ |
| 314 | extern int lttng_list_domains(const char *session_name, |
| 315 | struct lttng_domain **domains); |
| 316 | |
| 317 | /* |
| 318 | * List the channel(s) of a session. |
| 319 | * |
| 320 | * Return the size (number of entries) of the "lttng_channel" array. Caller |
| 321 | * must free(3). |
| 322 | */ |
| 323 | extern int lttng_list_channels(struct lttng_handle *handle, |
| 324 | struct lttng_channel **channels); |
| 325 | |
| 326 | /* |
| 327 | * List the event(s) of a session channel. |
| 328 | * |
| 329 | * Return the size (number of entries) of the "lttng_event" array. |
| 330 | * Caller must free(3). |
| 331 | */ |
| 332 | extern int lttng_list_events(struct lttng_handle *handle, |
| 333 | const char *channel_name, struct lttng_event **events); |
| 334 | |
| 335 | /* |
| 336 | * List the available tracepoints of a specific lttng domain. |
| 337 | * |
| 338 | * Return the size (number of entries) of the "lttng_event" array. |
| 339 | * Caller must free(3). |
| 340 | */ |
| 341 | extern int lttng_list_tracepoints(struct lttng_handle *handle, |
| 342 | struct lttng_event **events); |
| 343 | |
| 344 | /* |
| 345 | * Check if a session daemon is alive. |
| 346 | * |
| 347 | * Return 1 if alive or 0 if not. On error returns a negative value. |
| 348 | */ |
| 349 | extern int lttng_session_daemon_alive(void); |
| 350 | |
| 351 | /* |
| 352 | * Set the tracing group for the *current* flow of execution. |
| 353 | * |
| 354 | * On success, returns 0, on error, returns -1 (null name) or -ENOMEM. |
| 355 | */ |
| 356 | extern int lttng_set_tracing_group(const char *name); |
| 357 | |
| 358 | /* |
| 359 | * Return a human-readable error message for an lttng-tools error code. |
| 360 | * |
| 361 | * Parameter MUST be a negative value or else you'll get a generic message. |
| 362 | */ |
| 363 | extern const char *lttng_strerror(int code); |
| 364 | |
| 365 | /* |
| 366 | * This call registers an "outside consumer" for a session and an lttng domain. |
| 367 | * No consumer will be spawned and all fds/commands will go through the socket |
| 368 | * path given (socket_path). |
| 369 | * |
| 370 | * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the |
| 371 | * command socket. The error socket is not supported yet for roaming consumers. |
| 372 | */ |
| 373 | extern int lttng_register_consumer(struct lttng_handle *handle, |
| 374 | const char *socket_path); |
| 375 | |
| 376 | /* |
| 377 | * Start tracing for *all* registered traces (kernel and user-space). |
| 378 | */ |
| 379 | extern int lttng_start_tracing(const char *session_name); |
| 380 | |
| 381 | /* |
| 382 | * Stop tracing for *all* registered traces (kernel and user-space). |
| 383 | */ |
| 384 | extern int lttng_stop_tracing(const char *session_name); |
| 385 | |
| 386 | /* |
| 387 | * Add context to event(s) for a specific channel (or for all). |
| 388 | * |
| 389 | * If event_name is NULL, the context is applied to all events of the channel. |
| 390 | * If channel_name is NULL, a lookup of the event's channel is done. |
| 391 | * If both are NULL, the context is applied to all events of all channels. |
| 392 | */ |
| 393 | extern int lttng_add_context(struct lttng_handle *handle, |
| 394 | struct lttng_event_context *ctx, const char *event_name, |
| 395 | const char *channel_name); |
| 396 | |
| 397 | /* |
| 398 | * Create or enable a kernel event (or events) for a channel. |
| 399 | * |
| 400 | * If the event you are trying to enable does not exist, it will be created, |
| 401 | * else it is enabled. |
| 402 | * If event_name is NULL, all events are enabled. |
| 403 | * If channel_name is NULL, the default channel is used (channel0). |
| 404 | */ |
| 405 | extern int lttng_enable_event(struct lttng_handle *handle, |
| 406 | struct lttng_event *ev, const char *channel_name); |
| 407 | |
| 408 | /* |
| 409 | * Create or enable a kernel channel. |
| 410 | * The channel name cannot be NULL. |
| 411 | */ |
| 412 | extern int lttng_enable_channel(struct lttng_handle *handle, |
| 413 | struct lttng_channel *chan); |
| 414 | |
| 415 | /* |
| 416 | * Disable kernel event(s) of a channel and domain. |
| 417 | * |
| 418 | * If event_name is NULL, all events are disabled. |
| 419 | * If channel_name is NULL, the default channel is used (channel0). |
| 420 | */ |
| 421 | extern int lttng_disable_event(struct lttng_handle *handle, |
| 422 | const char *name, const char *channel_name); |
| 423 | |
| 424 | /* |
| 425 | * Disable kernel channel. |
| 426 | * |
| 427 | * The channel name cannot be NULL. |
| 428 | */ |
| 429 | extern int lttng_disable_channel(struct lttng_handle *handle, |
| 430 | const char *name); |
| 431 | |
| 432 | /* |
| 433 | * Calibrate LTTng overhead. |
| 434 | */ |
| 435 | extern int lttng_calibrate(struct lttng_handle *handle, |
| 436 | struct lttng_calibrate *calibrate); |
| 437 | |
| 438 | /* |
| 439 | * Set the default channel attributes for a specific domain and an allocated |
| 440 | * lttng_channel_attr pointer. |
| 441 | * |
| 442 | * If either or both of the arguments are NULL, nothing happens. |
| 443 | */ |
| 444 | extern void lttng_channel_set_default_attr(struct lttng_domain *domain, |
| 445 | struct lttng_channel_attr *attr); |
| 446 | |
| 447 | #endif /* _LTTNG_H */ |