| 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 program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License |
| 10 | * as published by the Free Software Foundation; either version 2 |
| 11 | * of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 21 | */ |
| 22 | |
| 23 | #ifndef _LTTNG_H |
| 24 | #define _LTTNG_H |
| 25 | |
| 26 | #include <asm/types.h> |
| 27 | #include <sys/types.h> |
| 28 | #include <stdint.h> |
| 29 | #include <limits.h> |
| 30 | |
| 31 | /* Default unix group name for tracing. */ |
| 32 | #define LTTNG_DEFAULT_TRACING_GROUP "tracing" |
| 33 | |
| 34 | /* Environment variable to set session daemon binary path. */ |
| 35 | #define LTTNG_SESSIOND_PATH_ENV "LTTNG_SESSIOND_PATH" |
| 36 | |
| 37 | /* Default trace output directory name */ |
| 38 | #define LTTNG_DEFAULT_TRACE_DIR_NAME "lttng-traces" |
| 39 | |
| 40 | /* |
| 41 | * Event symbol length. Copied from LTTng kernel ABI. |
| 42 | */ |
| 43 | #define LTTNG_SYMBOL_NAME_LEN 128 |
| 44 | |
| 45 | /* |
| 46 | * Every lttng_event_* structure both apply to kernel event and user-space |
| 47 | * event. |
| 48 | */ |
| 49 | |
| 50 | /* |
| 51 | * Domain type are the different possible tracers. |
| 52 | */ |
| 53 | enum lttng_domain_type { |
| 54 | LTTNG_DOMAIN_KERNEL, |
| 55 | LTTNG_DOMAIN_UST, |
| 56 | LTTNG_DOMAIN_UST_EXEC_NAME, |
| 57 | LTTNG_DOMAIN_UST_PID, |
| 58 | LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN, |
| 59 | }; |
| 60 | |
| 61 | struct lttng_domain { |
| 62 | enum lttng_domain_type type; |
| 63 | union { |
| 64 | pid_t pid; |
| 65 | char exec_name[NAME_MAX]; |
| 66 | } attr; |
| 67 | }; |
| 68 | |
| 69 | /* |
| 70 | * Instrumentation type of tracing event. |
| 71 | */ |
| 72 | enum lttng_event_type { |
| 73 | LTTNG_EVENT_TRACEPOINT, |
| 74 | LTTNG_EVENT_PROBE, |
| 75 | LTTNG_EVENT_FUNCTION, |
| 76 | }; |
| 77 | |
| 78 | /* |
| 79 | * LTTng consumer mode |
| 80 | */ |
| 81 | enum lttng_event_output { |
| 82 | LTTNG_EVENT_SPLICE = 0, |
| 83 | LTTNG_EVENT_MMAP = 1, |
| 84 | }; |
| 85 | |
| 86 | /* Event context possible type */ |
| 87 | enum lttng_event_context_type { |
| 88 | LTTNG_EVENT_CONTEXT_PID = 0, |
| 89 | LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1, |
| 90 | LTTNG_EVENT_CONTEXT_COMM = 2, |
| 91 | LTTNG_EVENT_CONTEXT_PRIO = 3, |
| 92 | LTTNG_EVENT_CONTEXT_NICE = 4, |
| 93 | LTTNG_EVENT_CONTEXT_VPID = 5, |
| 94 | LTTNG_EVENT_CONTEXT_TID = 6, |
| 95 | LTTNG_EVENT_CONTEXT_VTID = 7, |
| 96 | LTTNG_EVENT_CONTEXT_PPID = 8, |
| 97 | LTTNG_EVENT_CONTEXT_VPPID = 9, |
| 98 | }; |
| 99 | |
| 100 | /* Perf counter attributes */ |
| 101 | struct lttng_event_perf_counter_ctx { |
| 102 | uint32_t type; |
| 103 | uint64_t config; |
| 104 | char name[LTTNG_SYMBOL_NAME_LEN]; |
| 105 | }; |
| 106 | |
| 107 | /* Event/Channel context */ |
| 108 | struct lttng_event_context { |
| 109 | enum lttng_event_context_type ctx; |
| 110 | union { |
| 111 | struct lttng_event_perf_counter_ctx perf_counter; |
| 112 | } u; |
| 113 | }; |
| 114 | |
| 115 | /* |
| 116 | * Event probe. |
| 117 | * |
| 118 | * Either addr is used or symbol_name and offset. |
| 119 | */ |
| 120 | struct lttng_event_probe_attr { |
| 121 | uint64_t addr; |
| 122 | |
| 123 | uint64_t offset; |
| 124 | char symbol_name[LTTNG_SYMBOL_NAME_LEN]; |
| 125 | }; |
| 126 | |
| 127 | /* |
| 128 | * Function tracer |
| 129 | */ |
| 130 | struct lttng_event_function_attr { |
| 131 | char symbol_name[LTTNG_SYMBOL_NAME_LEN]; |
| 132 | }; |
| 133 | |
| 134 | /* |
| 135 | * Generic lttng event |
| 136 | */ |
| 137 | struct lttng_event { |
| 138 | char name[LTTNG_SYMBOL_NAME_LEN]; |
| 139 | enum lttng_event_type type; |
| 140 | /* Per event type configuration */ |
| 141 | union { |
| 142 | struct lttng_event_probe_attr probe; |
| 143 | struct lttng_event_function_attr ftrace; |
| 144 | } attr; |
| 145 | }; |
| 146 | |
| 147 | /* |
| 148 | * Tracer channel attributes. For both kernel and user-space. |
| 149 | */ |
| 150 | struct lttng_channel_attr { |
| 151 | int overwrite; /* 1: overwrite, 0: discard */ |
| 152 | uint64_t subbuf_size; /* bytes */ |
| 153 | uint64_t num_subbuf; /* power of 2 */ |
| 154 | unsigned int switch_timer_interval; /* usec */ |
| 155 | unsigned int read_timer_interval; /* usec */ |
| 156 | enum lttng_event_output output; /* splice, mmap */ |
| 157 | }; |
| 158 | |
| 159 | /* |
| 160 | * Channel information structure. For both kernel and user-space. |
| 161 | */ |
| 162 | struct lttng_channel { |
| 163 | char name[NAME_MAX]; |
| 164 | struct lttng_channel_attr attr; |
| 165 | }; |
| 166 | |
| 167 | /* |
| 168 | * Basic session information. |
| 169 | * |
| 170 | * This is an 'output data' meaning that it only comes *from* the session |
| 171 | * daemon *to* the lttng client. It's basically a 'human' representation of |
| 172 | * tracing entities (here a session). |
| 173 | */ |
| 174 | struct lttng_session { |
| 175 | char name[NAME_MAX]; |
| 176 | /* The path where traces are written */ |
| 177 | char path[PATH_MAX]; |
| 178 | }; |
| 179 | |
| 180 | /* |
| 181 | * Public LTTng control API |
| 182 | * |
| 183 | * For functions having a lttng domain type as parameter, if a bad value is |
| 184 | * given, NO default is applied and an error is returned. |
| 185 | * |
| 186 | * On success, all functions of the API return 0 or the size of the allocated |
| 187 | * array. |
| 188 | * |
| 189 | * On error, a negative value is returned being a specific lttng-tools error |
| 190 | * code which can be humanly interpreted with lttng_get_readable_code(err). |
| 191 | */ |
| 192 | |
| 193 | /* |
| 194 | * Session daemon control |
| 195 | */ |
| 196 | |
| 197 | /* |
| 198 | * Create tracing session using a name and a path where trace will be written. |
| 199 | */ |
| 200 | extern int lttng_create_session(const char *name, const char *path); |
| 201 | |
| 202 | /* |
| 203 | * Destroy tracing session. |
| 204 | * |
| 205 | * The session will not be useable anymore, tracing will stopped for all |
| 206 | * registered trace and tracing buffers will be flushed. |
| 207 | */ |
| 208 | extern int lttng_destroy_session(const char *name); |
| 209 | |
| 210 | /* |
| 211 | * List tracing sessions. |
| 212 | * |
| 213 | * Return the size of the "lttng_session" array. Caller must free(3) the |
| 214 | * returned data. |
| 215 | */ |
| 216 | extern int lttng_list_sessions(struct lttng_session **sessions); |
| 217 | |
| 218 | /* |
| 219 | * Check if a session daemon is alive. |
| 220 | */ |
| 221 | extern int lttng_session_daemon_alive(void); |
| 222 | |
| 223 | /* |
| 224 | * Set tracing group for the *current* flow of execution. |
| 225 | */ |
| 226 | extern int lttng_set_tracing_group(const char *name); |
| 227 | |
| 228 | /* |
| 229 | * Set the session name of the *current* flow of execution. |
| 230 | * |
| 231 | * This is a VERY important things to do before doing any tracing actions. If |
| 232 | * it's not done, you'll get an error saying that the session is not found. |
| 233 | * It avoids the use of a session name on every API call. |
| 234 | */ |
| 235 | extern void lttng_set_session_name(const char *name); |
| 236 | |
| 237 | /* |
| 238 | * Return a human readable error message of a lttng-tools error code. |
| 239 | * |
| 240 | * Parameter MUST be a negative value or else you'll get a generic message. |
| 241 | */ |
| 242 | extern const char *lttng_get_readable_code(int code); |
| 243 | |
| 244 | /* |
| 245 | * Start tracing for *all* registered trace (kernel and user-space). |
| 246 | */ |
| 247 | extern int lttng_start_tracing(const char *session_name); |
| 248 | |
| 249 | /* |
| 250 | * Stop tracing for *all* registered trace (kernel and user-space). |
| 251 | */ |
| 252 | extern int lttng_stop_tracing(const char *session_name); |
| 253 | |
| 254 | /* |
| 255 | * Add context to event for a specific channel. |
| 256 | * |
| 257 | * If event_name is NULL, the context is applied to all event of the channel. |
| 258 | * If channel_name is NULL, a lookup of the event's channel is done. |
| 259 | * If both are NULL, the context is applied on all events of all channels. |
| 260 | */ |
| 261 | |
| 262 | extern int lttng_add_context(struct lttng_domain *domain, |
| 263 | struct lttng_event_context *ctx, const char *event_name, |
| 264 | const char *channel_name); |
| 265 | |
| 266 | /* |
| 267 | * Create or enable a kernel event. |
| 268 | * |
| 269 | * If the event you are trying to enable does not exist, it will be created, |
| 270 | * else it is enabled. |
| 271 | * |
| 272 | * If channel_name is NULL, the default channel is used (channel0). |
| 273 | */ |
| 274 | extern int lttng_enable_event(struct lttng_domain *domain, struct lttng_event *ev, |
| 275 | const char *channel_name); |
| 276 | |
| 277 | /* |
| 278 | * Create or enable a kernel channel. |
| 279 | * |
| 280 | * If name is NULL, the default channel is enabled (channel0). |
| 281 | */ |
| 282 | extern int lttng_enable_channel(struct lttng_domain *domain, |
| 283 | struct lttng_channel *chan); |
| 284 | |
| 285 | /* |
| 286 | * Disable kernel event. |
| 287 | * |
| 288 | * If channel_name is NULL, the default channel is used (channel0). |
| 289 | */ |
| 290 | extern int lttng_disable_event(struct lttng_domain *domain, const char *name, |
| 291 | const char *channel_name); |
| 292 | |
| 293 | /* |
| 294 | * Disable kernel channel. |
| 295 | * |
| 296 | * If channel_name is NULL, the default channel is disabled (channel0). |
| 297 | */ |
| 298 | extern int lttng_disable_channel(struct lttng_domain *domain, |
| 299 | const char *name); |
| 300 | |
| 301 | /* |
| 302 | * List kernel events. |
| 303 | * |
| 304 | * Return the size of the allocated event list. Caller must free(3) the data. |
| 305 | */ |
| 306 | extern int lttng_list_events(struct lttng_domain *domain, char **event_list); |
| 307 | |
| 308 | #endif /* _LTTNG_H */ |