| 1 | /* |
| 2 | * lttng-ust-abi.c |
| 3 | * |
| 4 | * LTTng UST ABI |
| 5 | * |
| 6 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; only |
| 11 | * version 2.1 of the License. |
| 12 | * |
| 13 | * This library 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 GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with this library; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | * |
| 22 | * |
| 23 | * Mimic system calls for: |
| 24 | * - session creation, returns an object descriptor or failure. |
| 25 | * - channel creation, returns an object descriptor or failure. |
| 26 | * - Operates on a session object descriptor |
| 27 | * - Takes all channel options as parameters. |
| 28 | * - stream get, returns an object descriptor or failure. |
| 29 | * - Operates on a channel object descriptor. |
| 30 | * - stream notifier get, returns an object descriptor or failure. |
| 31 | * - Operates on a channel object descriptor. |
| 32 | * - event creation, returns an object descriptor or failure. |
| 33 | * - Operates on a channel object descriptor |
| 34 | * - Takes an event name as parameter |
| 35 | * - Takes an instrumentation source as parameter |
| 36 | * - e.g. tracepoints, dynamic_probes... |
| 37 | * - Takes instrumentation source specific arguments. |
| 38 | */ |
| 39 | |
| 40 | #include <lttng/ust-abi.h> |
| 41 | #include <lttng/ust-error.h> |
| 42 | #include <urcu/compiler.h> |
| 43 | #include <urcu/list.h> |
| 44 | #include <lttng/ust-events.h> |
| 45 | #include <lttng/ust-version.h> |
| 46 | #include <lttng/tracepoint.h> |
| 47 | #include "tracepoint-internal.h" |
| 48 | #include <usterr-signal-safe.h> |
| 49 | #include <helper.h> |
| 50 | #include "lttng-tracer.h" |
| 51 | #include "../libringbuffer/shm.h" |
| 52 | #include "../libringbuffer/frontend_types.h" |
| 53 | |
| 54 | #define OBJ_NAME_LEN 16 |
| 55 | |
| 56 | static int lttng_ust_abi_close_in_progress; |
| 57 | |
| 58 | static |
| 59 | int lttng_abi_tracepoint_list(void *owner); |
| 60 | static |
| 61 | int lttng_abi_tracepoint_field_list(void *owner); |
| 62 | |
| 63 | /* |
| 64 | * Object descriptor table. Should be protected from concurrent access |
| 65 | * by the caller. |
| 66 | */ |
| 67 | |
| 68 | struct lttng_ust_obj { |
| 69 | union { |
| 70 | struct { |
| 71 | void *private_data; |
| 72 | const struct lttng_ust_objd_ops *ops; |
| 73 | int f_count; |
| 74 | int owner_ref; /* has ref from owner */ |
| 75 | void *owner; |
| 76 | char name[OBJ_NAME_LEN]; |
| 77 | } s; |
| 78 | int freelist_next; /* offset freelist. end is -1. */ |
| 79 | } u; |
| 80 | }; |
| 81 | |
| 82 | struct lttng_ust_objd_table { |
| 83 | struct lttng_ust_obj *array; |
| 84 | unsigned int len, allocated_len; |
| 85 | int freelist_head; /* offset freelist head. end is -1 */ |
| 86 | }; |
| 87 | |
| 88 | static struct lttng_ust_objd_table objd_table = { |
| 89 | .freelist_head = -1, |
| 90 | }; |
| 91 | |
| 92 | static |
| 93 | int objd_alloc(void *private_data, const struct lttng_ust_objd_ops *ops, |
| 94 | void *owner, const char *name) |
| 95 | { |
| 96 | struct lttng_ust_obj *obj; |
| 97 | |
| 98 | if (objd_table.freelist_head != -1) { |
| 99 | obj = &objd_table.array[objd_table.freelist_head]; |
| 100 | objd_table.freelist_head = obj->u.freelist_next; |
| 101 | goto end; |
| 102 | } |
| 103 | |
| 104 | if (objd_table.len >= objd_table.allocated_len) { |
| 105 | unsigned int new_allocated_len, old_allocated_len; |
| 106 | struct lttng_ust_obj *new_table, *old_table; |
| 107 | |
| 108 | old_allocated_len = objd_table.allocated_len; |
| 109 | old_table = objd_table.array; |
| 110 | if (!old_allocated_len) |
| 111 | new_allocated_len = 1; |
| 112 | else |
| 113 | new_allocated_len = old_allocated_len << 1; |
| 114 | new_table = zmalloc(sizeof(struct lttng_ust_obj) * new_allocated_len); |
| 115 | if (!new_table) |
| 116 | return -ENOMEM; |
| 117 | memcpy(new_table, old_table, |
| 118 | sizeof(struct lttng_ust_obj) * old_allocated_len); |
| 119 | free(old_table); |
| 120 | objd_table.array = new_table; |
| 121 | objd_table.allocated_len = new_allocated_len; |
| 122 | } |
| 123 | obj = &objd_table.array[objd_table.len]; |
| 124 | objd_table.len++; |
| 125 | end: |
| 126 | obj->u.s.private_data = private_data; |
| 127 | obj->u.s.ops = ops; |
| 128 | obj->u.s.f_count = 2; /* count == 1 : object is allocated */ |
| 129 | /* count == 2 : allocated + hold ref */ |
| 130 | obj->u.s.owner_ref = 1; /* One owner reference */ |
| 131 | obj->u.s.owner = owner; |
| 132 | strncpy(obj->u.s.name, name, OBJ_NAME_LEN); |
| 133 | obj->u.s.name[OBJ_NAME_LEN - 1] = '\0'; |
| 134 | return obj - objd_table.array; |
| 135 | } |
| 136 | |
| 137 | static |
| 138 | struct lttng_ust_obj *_objd_get(int id) |
| 139 | { |
| 140 | if (id >= objd_table.len) |
| 141 | return NULL; |
| 142 | if (!objd_table.array[id].u.s.f_count) |
| 143 | return NULL; |
| 144 | return &objd_table.array[id]; |
| 145 | } |
| 146 | |
| 147 | static |
| 148 | void *objd_private(int id) |
| 149 | { |
| 150 | struct lttng_ust_obj *obj = _objd_get(id); |
| 151 | assert(obj); |
| 152 | return obj->u.s.private_data; |
| 153 | } |
| 154 | |
| 155 | static |
| 156 | void objd_set_private(int id, void *private_data) |
| 157 | { |
| 158 | struct lttng_ust_obj *obj = _objd_get(id); |
| 159 | assert(obj); |
| 160 | obj->u.s.private_data = private_data; |
| 161 | } |
| 162 | |
| 163 | const struct lttng_ust_objd_ops *objd_ops(int id) |
| 164 | { |
| 165 | struct lttng_ust_obj *obj = _objd_get(id); |
| 166 | |
| 167 | if (!obj) |
| 168 | return NULL; |
| 169 | return obj->u.s.ops; |
| 170 | } |
| 171 | |
| 172 | static |
| 173 | void objd_free(int id) |
| 174 | { |
| 175 | struct lttng_ust_obj *obj = _objd_get(id); |
| 176 | |
| 177 | assert(obj); |
| 178 | obj->u.freelist_next = objd_table.freelist_head; |
| 179 | objd_table.freelist_head = obj - objd_table.array; |
| 180 | assert(obj->u.s.f_count == 1); |
| 181 | obj->u.s.f_count = 0; /* deallocated */ |
| 182 | } |
| 183 | |
| 184 | static |
| 185 | void objd_ref(int id) |
| 186 | { |
| 187 | struct lttng_ust_obj *obj = _objd_get(id); |
| 188 | assert(obj != NULL); |
| 189 | obj->u.s.f_count++; |
| 190 | } |
| 191 | |
| 192 | int lttng_ust_objd_unref(int id, int is_owner) |
| 193 | { |
| 194 | struct lttng_ust_obj *obj = _objd_get(id); |
| 195 | |
| 196 | if (!obj) |
| 197 | return -EINVAL; |
| 198 | if (obj->u.s.f_count == 1) { |
| 199 | ERR("Reference counting error\n"); |
| 200 | return -EINVAL; |
| 201 | } |
| 202 | if (is_owner) { |
| 203 | if (!obj->u.s.owner_ref) { |
| 204 | ERR("Error decrementing owner reference"); |
| 205 | return -EINVAL; |
| 206 | } |
| 207 | obj->u.s.owner_ref--; |
| 208 | } |
| 209 | if ((--obj->u.s.f_count) == 1) { |
| 210 | const struct lttng_ust_objd_ops *ops = objd_ops(id); |
| 211 | |
| 212 | if (ops->release) |
| 213 | ops->release(id); |
| 214 | objd_free(id); |
| 215 | } |
| 216 | return 0; |
| 217 | } |
| 218 | |
| 219 | static |
| 220 | void objd_table_destroy(void) |
| 221 | { |
| 222 | int i; |
| 223 | |
| 224 | for (i = 0; i < objd_table.allocated_len; i++) { |
| 225 | struct lttng_ust_obj *obj; |
| 226 | |
| 227 | obj = _objd_get(i); |
| 228 | if (!obj) |
| 229 | continue; |
| 230 | if (!obj->u.s.owner_ref) |
| 231 | continue; /* only unref owner ref. */ |
| 232 | (void) lttng_ust_objd_unref(i, 1); |
| 233 | } |
| 234 | free(objd_table.array); |
| 235 | objd_table.array = NULL; |
| 236 | objd_table.len = 0; |
| 237 | objd_table.allocated_len = 0; |
| 238 | objd_table.freelist_head = -1; |
| 239 | } |
| 240 | |
| 241 | const char *lttng_ust_obj_get_name(int id) |
| 242 | { |
| 243 | struct lttng_ust_obj *obj = _objd_get(id); |
| 244 | |
| 245 | if (!obj) |
| 246 | return NULL; |
| 247 | return obj->u.s.name; |
| 248 | } |
| 249 | |
| 250 | void lttng_ust_objd_table_owner_cleanup(void *owner) |
| 251 | { |
| 252 | int i; |
| 253 | |
| 254 | for (i = 0; i < objd_table.allocated_len; i++) { |
| 255 | struct lttng_ust_obj *obj; |
| 256 | |
| 257 | obj = _objd_get(i); |
| 258 | if (!obj) |
| 259 | continue; |
| 260 | if (!obj->u.s.owner) |
| 261 | continue; /* skip root handles */ |
| 262 | if (!obj->u.s.owner_ref) |
| 263 | continue; /* only unref owner ref. */ |
| 264 | if (obj->u.s.owner == owner) |
| 265 | (void) lttng_ust_objd_unref(i, 1); |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | /* |
| 270 | * This is LTTng's own personal way to create an ABI for sessiond. |
| 271 | * We send commands over a socket. |
| 272 | */ |
| 273 | |
| 274 | static const struct lttng_ust_objd_ops lttng_ops; |
| 275 | static const struct lttng_ust_objd_ops lttng_session_ops; |
| 276 | static const struct lttng_ust_objd_ops lttng_channel_ops; |
| 277 | static const struct lttng_ust_objd_ops lttng_enabler_ops; |
| 278 | static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops; |
| 279 | static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops; |
| 280 | |
| 281 | int lttng_abi_create_root_handle(void) |
| 282 | { |
| 283 | int root_handle; |
| 284 | |
| 285 | /* root handles have NULL owners */ |
| 286 | root_handle = objd_alloc(NULL, <tng_ops, NULL, "root"); |
| 287 | return root_handle; |
| 288 | } |
| 289 | |
| 290 | static |
| 291 | int lttng_is_channel_ready(struct lttng_channel *lttng_chan) |
| 292 | { |
| 293 | struct channel *chan; |
| 294 | unsigned int nr_streams, exp_streams; |
| 295 | |
| 296 | chan = lttng_chan->chan; |
| 297 | nr_streams = channel_handle_get_nr_streams(lttng_chan->handle); |
| 298 | exp_streams = chan->nr_streams; |
| 299 | return nr_streams == exp_streams; |
| 300 | } |
| 301 | |
| 302 | static |
| 303 | int lttng_abi_create_session(void *owner) |
| 304 | { |
| 305 | struct lttng_session *session; |
| 306 | int session_objd, ret; |
| 307 | |
| 308 | session = lttng_session_create(); |
| 309 | if (!session) |
| 310 | return -ENOMEM; |
| 311 | session_objd = objd_alloc(session, <tng_session_ops, owner, "session"); |
| 312 | if (session_objd < 0) { |
| 313 | ret = session_objd; |
| 314 | goto objd_error; |
| 315 | } |
| 316 | session->objd = session_objd; |
| 317 | session->owner = owner; |
| 318 | return session_objd; |
| 319 | |
| 320 | objd_error: |
| 321 | lttng_session_destroy(session); |
| 322 | return ret; |
| 323 | } |
| 324 | |
| 325 | static |
| 326 | long lttng_abi_tracer_version(int objd, |
| 327 | struct lttng_ust_tracer_version *v) |
| 328 | { |
| 329 | v->major = LTTNG_UST_MAJOR_VERSION; |
| 330 | v->minor = LTTNG_UST_MINOR_VERSION; |
| 331 | v->patchlevel = LTTNG_UST_PATCHLEVEL_VERSION; |
| 332 | return 0; |
| 333 | } |
| 334 | |
| 335 | static |
| 336 | long lttng_abi_add_context(int objd, |
| 337 | struct lttng_ust_context *context_param, |
| 338 | union ust_args *uargs, |
| 339 | struct lttng_ctx **ctx, struct lttng_session *session) |
| 340 | { |
| 341 | return lttng_attach_context(context_param, uargs, ctx, session); |
| 342 | } |
| 343 | |
| 344 | /** |
| 345 | * lttng_cmd - lttng control through socket commands |
| 346 | * |
| 347 | * @objd: the object descriptor |
| 348 | * @cmd: the command |
| 349 | * @arg: command arg |
| 350 | * @uargs: UST arguments (internal) |
| 351 | * @owner: objd owner |
| 352 | * |
| 353 | * This descriptor implements lttng commands: |
| 354 | * LTTNG_UST_SESSION |
| 355 | * Returns a LTTng trace session object descriptor |
| 356 | * LTTNG_UST_TRACER_VERSION |
| 357 | * Returns the LTTng kernel tracer version |
| 358 | * LTTNG_UST_TRACEPOINT_LIST |
| 359 | * Returns a file descriptor listing available tracepoints |
| 360 | * LTTNG_UST_TRACEPOINT_FIELD_LIST |
| 361 | * Returns a file descriptor listing available tracepoint fields |
| 362 | * LTTNG_UST_WAIT_QUIESCENT |
| 363 | * Returns after all previously running probes have completed |
| 364 | * |
| 365 | * The returned session will be deleted when its file descriptor is closed. |
| 366 | */ |
| 367 | static |
| 368 | long lttng_cmd(int objd, unsigned int cmd, unsigned long arg, |
| 369 | union ust_args *uargs, void *owner) |
| 370 | { |
| 371 | switch (cmd) { |
| 372 | case LTTNG_UST_SESSION: |
| 373 | return lttng_abi_create_session(owner); |
| 374 | case LTTNG_UST_TRACER_VERSION: |
| 375 | return lttng_abi_tracer_version(objd, |
| 376 | (struct lttng_ust_tracer_version *) arg); |
| 377 | case LTTNG_UST_TRACEPOINT_LIST: |
| 378 | return lttng_abi_tracepoint_list(owner); |
| 379 | case LTTNG_UST_TRACEPOINT_FIELD_LIST: |
| 380 | return lttng_abi_tracepoint_field_list(owner); |
| 381 | case LTTNG_UST_WAIT_QUIESCENT: |
| 382 | synchronize_trace(); |
| 383 | return 0; |
| 384 | default: |
| 385 | return -EINVAL; |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | static const struct lttng_ust_objd_ops lttng_ops = { |
| 390 | .cmd = lttng_cmd, |
| 391 | }; |
| 392 | |
| 393 | int lttng_abi_map_channel(int session_objd, |
| 394 | struct lttng_ust_channel *ust_chan, |
| 395 | union ust_args *uargs, |
| 396 | void *owner) |
| 397 | { |
| 398 | struct lttng_session *session = objd_private(session_objd); |
| 399 | const char *transport_name; |
| 400 | const struct lttng_transport *transport; |
| 401 | const char *chan_name; |
| 402 | int chan_objd; |
| 403 | struct lttng_ust_shm_handle *channel_handle; |
| 404 | struct lttng_channel *lttng_chan; |
| 405 | struct channel *chan; |
| 406 | struct lttng_ust_lib_ring_buffer_config *config; |
| 407 | void *chan_data; |
| 408 | int wakeup_fd; |
| 409 | uint64_t len; |
| 410 | int ret; |
| 411 | enum lttng_ust_chan_type type; |
| 412 | |
| 413 | chan_data = uargs->channel.chan_data; |
| 414 | wakeup_fd = uargs->channel.wakeup_fd; |
| 415 | len = ust_chan->len; |
| 416 | type = ust_chan->type; |
| 417 | |
| 418 | switch (type) { |
| 419 | case LTTNG_UST_CHAN_PER_CPU: |
| 420 | break; |
| 421 | default: |
| 422 | ret = -EINVAL; |
| 423 | goto invalid; |
| 424 | } |
| 425 | |
| 426 | if (session->been_active) { |
| 427 | ret = -EBUSY; |
| 428 | goto active; /* Refuse to add channel to active session */ |
| 429 | } |
| 430 | |
| 431 | channel_handle = channel_handle_create(chan_data, len, wakeup_fd); |
| 432 | if (!channel_handle) { |
| 433 | ret = -EINVAL; |
| 434 | goto handle_error; |
| 435 | } |
| 436 | |
| 437 | chan = shmp(channel_handle, channel_handle->chan); |
| 438 | assert(chan); |
| 439 | chan->handle = channel_handle; |
| 440 | config = &chan->backend.config; |
| 441 | lttng_chan = channel_get_private(chan); |
| 442 | if (!lttng_chan) { |
| 443 | ret = -EINVAL; |
| 444 | goto alloc_error; |
| 445 | } |
| 446 | |
| 447 | /* Lookup transport name */ |
| 448 | switch (type) { |
| 449 | case LTTNG_UST_CHAN_PER_CPU: |
| 450 | if (config->output == RING_BUFFER_MMAP) { |
| 451 | if (config->mode == RING_BUFFER_OVERWRITE) { |
| 452 | if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER) { |
| 453 | transport_name = "relay-overwrite-mmap"; |
| 454 | } else { |
| 455 | transport_name = "relay-overwrite-rt-mmap"; |
| 456 | } |
| 457 | } else { |
| 458 | if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER) { |
| 459 | transport_name = "relay-discard-mmap"; |
| 460 | } else { |
| 461 | transport_name = "relay-discard-rt-mmap"; |
| 462 | } |
| 463 | } |
| 464 | } else { |
| 465 | ret = -EINVAL; |
| 466 | goto notransport; |
| 467 | } |
| 468 | chan_name = "channel"; |
| 469 | break; |
| 470 | default: |
| 471 | ret = -EINVAL; |
| 472 | goto notransport; |
| 473 | } |
| 474 | transport = lttng_transport_find(transport_name); |
| 475 | if (!transport) { |
| 476 | DBG("LTTng transport %s not found\n", |
| 477 | transport_name); |
| 478 | ret = -EINVAL; |
| 479 | goto notransport; |
| 480 | } |
| 481 | |
| 482 | chan_objd = objd_alloc(NULL, <tng_channel_ops, owner, chan_name); |
| 483 | if (chan_objd < 0) { |
| 484 | ret = chan_objd; |
| 485 | goto objd_error; |
| 486 | } |
| 487 | |
| 488 | /* Initialize our lttng chan */ |
| 489 | lttng_chan->chan = chan; |
| 490 | lttng_chan->tstate = 1; |
| 491 | lttng_chan->enabled = 1; |
| 492 | lttng_chan->ctx = NULL; |
| 493 | lttng_chan->session = session; |
| 494 | lttng_chan->ops = &transport->ops; |
| 495 | memcpy(<tng_chan->chan->backend.config, |
| 496 | transport->client_config, |
| 497 | sizeof(lttng_chan->chan->backend.config)); |
| 498 | cds_list_add(<tng_chan->node, &session->chan_head); |
| 499 | lttng_chan->header_type = 0; |
| 500 | lttng_chan->handle = channel_handle; |
| 501 | lttng_chan->type = type; |
| 502 | |
| 503 | /* |
| 504 | * We tolerate no failure path after channel creation. It will stay |
| 505 | * invariant for the rest of the session. |
| 506 | */ |
| 507 | objd_set_private(chan_objd, lttng_chan); |
| 508 | lttng_chan->objd = chan_objd; |
| 509 | /* The channel created holds a reference on the session */ |
| 510 | objd_ref(session_objd); |
| 511 | return chan_objd; |
| 512 | |
| 513 | /* error path after channel was created */ |
| 514 | objd_error: |
| 515 | notransport: |
| 516 | alloc_error: |
| 517 | channel_destroy(chan, channel_handle, 0); |
| 518 | return ret; |
| 519 | |
| 520 | /* |
| 521 | * error path before channel creation (owning chan_data and |
| 522 | * wakeup_fd). |
| 523 | */ |
| 524 | handle_error: |
| 525 | active: |
| 526 | invalid: |
| 527 | { |
| 528 | int close_ret; |
| 529 | |
| 530 | close_ret = close(wakeup_fd); |
| 531 | if (close_ret) { |
| 532 | PERROR("close"); |
| 533 | } |
| 534 | } |
| 535 | free(chan_data); |
| 536 | return ret; |
| 537 | } |
| 538 | |
| 539 | /** |
| 540 | * lttng_session_cmd - lttng session object command |
| 541 | * |
| 542 | * @obj: the object |
| 543 | * @cmd: the command |
| 544 | * @arg: command arg |
| 545 | * @uargs: UST arguments (internal) |
| 546 | * @owner: objd owner |
| 547 | * |
| 548 | * This descriptor implements lttng commands: |
| 549 | * LTTNG_UST_CHANNEL |
| 550 | * Returns a LTTng channel object descriptor |
| 551 | * LTTNG_UST_ENABLE |
| 552 | * Enables tracing for a session (weak enable) |
| 553 | * LTTNG_UST_DISABLE |
| 554 | * Disables tracing for a session (strong disable) |
| 555 | * |
| 556 | * The returned channel will be deleted when its file descriptor is closed. |
| 557 | */ |
| 558 | static |
| 559 | long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg, |
| 560 | union ust_args *uargs, void *owner) |
| 561 | { |
| 562 | struct lttng_session *session = objd_private(objd); |
| 563 | |
| 564 | switch (cmd) { |
| 565 | case LTTNG_UST_CHANNEL: |
| 566 | return lttng_abi_map_channel(objd, |
| 567 | (struct lttng_ust_channel *) arg, |
| 568 | uargs, owner); |
| 569 | case LTTNG_UST_SESSION_START: |
| 570 | case LTTNG_UST_ENABLE: |
| 571 | return lttng_session_enable(session); |
| 572 | case LTTNG_UST_SESSION_STOP: |
| 573 | case LTTNG_UST_DISABLE: |
| 574 | return lttng_session_disable(session); |
| 575 | case LTTNG_UST_SESSION_STATEDUMP: |
| 576 | return lttng_session_statedump(session); |
| 577 | default: |
| 578 | return -EINVAL; |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | /* |
| 583 | * Called when the last file reference is dropped. |
| 584 | * |
| 585 | * Big fat note: channels and events are invariant for the whole session after |
| 586 | * their creation. So this session destruction also destroys all channel and |
| 587 | * event structures specific to this session (they are not destroyed when their |
| 588 | * individual file is released). |
| 589 | */ |
| 590 | static |
| 591 | int lttng_release_session(int objd) |
| 592 | { |
| 593 | struct lttng_session *session = objd_private(objd); |
| 594 | |
| 595 | if (session) { |
| 596 | lttng_session_destroy(session); |
| 597 | return 0; |
| 598 | } else { |
| 599 | return -EINVAL; |
| 600 | } |
| 601 | } |
| 602 | |
| 603 | static const struct lttng_ust_objd_ops lttng_session_ops = { |
| 604 | .release = lttng_release_session, |
| 605 | .cmd = lttng_session_cmd, |
| 606 | }; |
| 607 | |
| 608 | static |
| 609 | long lttng_tracepoint_list_cmd(int objd, unsigned int cmd, unsigned long arg, |
| 610 | union ust_args *uargs, void *owner) |
| 611 | { |
| 612 | struct lttng_ust_tracepoint_list *list = objd_private(objd); |
| 613 | struct lttng_ust_tracepoint_iter *tp = |
| 614 | (struct lttng_ust_tracepoint_iter *) arg; |
| 615 | struct lttng_ust_tracepoint_iter *iter; |
| 616 | |
| 617 | switch (cmd) { |
| 618 | case LTTNG_UST_TRACEPOINT_LIST_GET: |
| 619 | { |
| 620 | iter = lttng_ust_tracepoint_list_get_iter_next(list); |
| 621 | if (!iter) |
| 622 | return -LTTNG_UST_ERR_NOENT; |
| 623 | memcpy(tp, iter, sizeof(*tp)); |
| 624 | return 0; |
| 625 | } |
| 626 | default: |
| 627 | return -EINVAL; |
| 628 | } |
| 629 | } |
| 630 | |
| 631 | static |
| 632 | int lttng_abi_tracepoint_list(void *owner) |
| 633 | { |
| 634 | int list_objd, ret; |
| 635 | struct lttng_ust_tracepoint_list *list; |
| 636 | |
| 637 | list_objd = objd_alloc(NULL, <tng_tracepoint_list_ops, owner, "tp_list"); |
| 638 | if (list_objd < 0) { |
| 639 | ret = list_objd; |
| 640 | goto objd_error; |
| 641 | } |
| 642 | list = zmalloc(sizeof(*list)); |
| 643 | if (!list) { |
| 644 | ret = -ENOMEM; |
| 645 | goto alloc_error; |
| 646 | } |
| 647 | objd_set_private(list_objd, list); |
| 648 | |
| 649 | /* populate list by walking on all registered probes. */ |
| 650 | ret = lttng_probes_get_event_list(list); |
| 651 | if (ret) { |
| 652 | goto list_error; |
| 653 | } |
| 654 | return list_objd; |
| 655 | |
| 656 | list_error: |
| 657 | free(list); |
| 658 | alloc_error: |
| 659 | { |
| 660 | int err; |
| 661 | |
| 662 | err = lttng_ust_objd_unref(list_objd, 1); |
| 663 | assert(!err); |
| 664 | } |
| 665 | objd_error: |
| 666 | return ret; |
| 667 | } |
| 668 | |
| 669 | static |
| 670 | int lttng_release_tracepoint_list(int objd) |
| 671 | { |
| 672 | struct lttng_ust_tracepoint_list *list = objd_private(objd); |
| 673 | |
| 674 | if (list) { |
| 675 | lttng_probes_prune_event_list(list); |
| 676 | free(list); |
| 677 | return 0; |
| 678 | } else { |
| 679 | return -EINVAL; |
| 680 | } |
| 681 | } |
| 682 | |
| 683 | static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops = { |
| 684 | .release = lttng_release_tracepoint_list, |
| 685 | .cmd = lttng_tracepoint_list_cmd, |
| 686 | }; |
| 687 | |
| 688 | static |
| 689 | long lttng_tracepoint_field_list_cmd(int objd, unsigned int cmd, |
| 690 | unsigned long arg, union ust_args *uargs, void *owner) |
| 691 | { |
| 692 | struct lttng_ust_field_list *list = objd_private(objd); |
| 693 | struct lttng_ust_field_iter *tp = &uargs->field_list.entry; |
| 694 | struct lttng_ust_field_iter *iter; |
| 695 | |
| 696 | switch (cmd) { |
| 697 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: |
| 698 | { |
| 699 | iter = lttng_ust_field_list_get_iter_next(list); |
| 700 | if (!iter) |
| 701 | return -LTTNG_UST_ERR_NOENT; |
| 702 | memcpy(tp, iter, sizeof(*tp)); |
| 703 | return 0; |
| 704 | } |
| 705 | default: |
| 706 | return -EINVAL; |
| 707 | } |
| 708 | } |
| 709 | |
| 710 | static |
| 711 | int lttng_abi_tracepoint_field_list(void *owner) |
| 712 | { |
| 713 | int list_objd, ret; |
| 714 | struct lttng_ust_field_list *list; |
| 715 | |
| 716 | list_objd = objd_alloc(NULL, <tng_tracepoint_field_list_ops, owner, |
| 717 | "tp_field_list"); |
| 718 | if (list_objd < 0) { |
| 719 | ret = list_objd; |
| 720 | goto objd_error; |
| 721 | } |
| 722 | list = zmalloc(sizeof(*list)); |
| 723 | if (!list) { |
| 724 | ret = -ENOMEM; |
| 725 | goto alloc_error; |
| 726 | } |
| 727 | objd_set_private(list_objd, list); |
| 728 | |
| 729 | /* populate list by walking on all registered probes. */ |
| 730 | ret = lttng_probes_get_field_list(list); |
| 731 | if (ret) { |
| 732 | goto list_error; |
| 733 | } |
| 734 | return list_objd; |
| 735 | |
| 736 | list_error: |
| 737 | free(list); |
| 738 | alloc_error: |
| 739 | { |
| 740 | int err; |
| 741 | |
| 742 | err = lttng_ust_objd_unref(list_objd, 1); |
| 743 | assert(!err); |
| 744 | } |
| 745 | objd_error: |
| 746 | return ret; |
| 747 | } |
| 748 | |
| 749 | static |
| 750 | int lttng_release_tracepoint_field_list(int objd) |
| 751 | { |
| 752 | struct lttng_ust_field_list *list = objd_private(objd); |
| 753 | |
| 754 | if (list) { |
| 755 | lttng_probes_prune_field_list(list); |
| 756 | free(list); |
| 757 | return 0; |
| 758 | } else { |
| 759 | return -EINVAL; |
| 760 | } |
| 761 | } |
| 762 | |
| 763 | static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops = { |
| 764 | .release = lttng_release_tracepoint_field_list, |
| 765 | .cmd = lttng_tracepoint_field_list_cmd, |
| 766 | }; |
| 767 | |
| 768 | static |
| 769 | int lttng_abi_map_stream(int channel_objd, struct lttng_ust_stream *info, |
| 770 | union ust_args *uargs, void *owner) |
| 771 | { |
| 772 | struct lttng_channel *channel = objd_private(channel_objd); |
| 773 | int ret; |
| 774 | |
| 775 | ret = channel_handle_add_stream(channel->handle, |
| 776 | uargs->stream.shm_fd, uargs->stream.wakeup_fd, |
| 777 | info->stream_nr, info->len); |
| 778 | if (ret) |
| 779 | goto error_add_stream; |
| 780 | |
| 781 | return 0; |
| 782 | |
| 783 | error_add_stream: |
| 784 | return ret; |
| 785 | } |
| 786 | |
| 787 | static |
| 788 | int lttng_abi_create_enabler(int channel_objd, |
| 789 | struct lttng_ust_event *event_param, |
| 790 | void *owner, |
| 791 | enum lttng_enabler_type type) |
| 792 | { |
| 793 | struct lttng_channel *channel = objd_private(channel_objd); |
| 794 | struct lttng_enabler *enabler; |
| 795 | int event_objd, ret; |
| 796 | |
| 797 | event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; |
| 798 | event_objd = objd_alloc(NULL, <tng_enabler_ops, owner, "enabler"); |
| 799 | if (event_objd < 0) { |
| 800 | ret = event_objd; |
| 801 | goto objd_error; |
| 802 | } |
| 803 | /* |
| 804 | * We tolerate no failure path after event creation. It will stay |
| 805 | * invariant for the rest of the session. |
| 806 | */ |
| 807 | enabler = lttng_enabler_create(type, event_param, channel); |
| 808 | if (!enabler) { |
| 809 | ret = -ENOMEM; |
| 810 | goto event_error; |
| 811 | } |
| 812 | objd_set_private(event_objd, enabler); |
| 813 | /* The event holds a reference on the channel */ |
| 814 | objd_ref(channel_objd); |
| 815 | return event_objd; |
| 816 | |
| 817 | event_error: |
| 818 | { |
| 819 | int err; |
| 820 | |
| 821 | err = lttng_ust_objd_unref(event_objd, 1); |
| 822 | assert(!err); |
| 823 | } |
| 824 | objd_error: |
| 825 | return ret; |
| 826 | } |
| 827 | |
| 828 | /** |
| 829 | * lttng_channel_cmd - lttng control through object descriptors |
| 830 | * |
| 831 | * @objd: the object descriptor |
| 832 | * @cmd: the command |
| 833 | * @arg: command arg |
| 834 | * @uargs: UST arguments (internal) |
| 835 | * @owner: objd owner |
| 836 | * |
| 837 | * This object descriptor implements lttng commands: |
| 838 | * LTTNG_UST_STREAM |
| 839 | * Returns an event stream object descriptor or failure. |
| 840 | * (typically, one event stream records events from one CPU) |
| 841 | * LTTNG_UST_EVENT |
| 842 | * Returns an event object descriptor or failure. |
| 843 | * LTTNG_UST_CONTEXT |
| 844 | * Prepend a context field to each event in the channel |
| 845 | * LTTNG_UST_ENABLE |
| 846 | * Enable recording for events in this channel (weak enable) |
| 847 | * LTTNG_UST_DISABLE |
| 848 | * Disable recording for events in this channel (strong disable) |
| 849 | * |
| 850 | * Channel and event file descriptors also hold a reference on the session. |
| 851 | */ |
| 852 | static |
| 853 | long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg, |
| 854 | union ust_args *uargs, void *owner) |
| 855 | { |
| 856 | struct lttng_channel *channel = objd_private(objd); |
| 857 | |
| 858 | if (cmd != LTTNG_UST_STREAM) { |
| 859 | /* |
| 860 | * Check if channel received all streams. |
| 861 | */ |
| 862 | if (!lttng_is_channel_ready(channel)) |
| 863 | return -EPERM; |
| 864 | } |
| 865 | |
| 866 | switch (cmd) { |
| 867 | case LTTNG_UST_STREAM: |
| 868 | { |
| 869 | struct lttng_ust_stream *stream; |
| 870 | |
| 871 | stream = (struct lttng_ust_stream *) arg; |
| 872 | /* stream used as output */ |
| 873 | return lttng_abi_map_stream(objd, stream, uargs, owner); |
| 874 | } |
| 875 | case LTTNG_UST_EVENT: |
| 876 | { |
| 877 | struct lttng_ust_event *event_param = |
| 878 | (struct lttng_ust_event *) arg; |
| 879 | if (event_param->name[strlen(event_param->name) - 1] == '*') { |
| 880 | /* If ends with wildcard, create wildcard. */ |
| 881 | return lttng_abi_create_enabler(objd, event_param, |
| 882 | owner, LTTNG_ENABLER_WILDCARD); |
| 883 | } else { |
| 884 | return lttng_abi_create_enabler(objd, event_param, |
| 885 | owner, LTTNG_ENABLER_EVENT); |
| 886 | } |
| 887 | } |
| 888 | case LTTNG_UST_CONTEXT: |
| 889 | return lttng_abi_add_context(objd, |
| 890 | (struct lttng_ust_context *) arg, uargs, |
| 891 | &channel->ctx, channel->session); |
| 892 | case LTTNG_UST_ENABLE: |
| 893 | return lttng_channel_enable(channel); |
| 894 | case LTTNG_UST_DISABLE: |
| 895 | return lttng_channel_disable(channel); |
| 896 | case LTTNG_UST_FLUSH_BUFFER: |
| 897 | return channel->ops->flush_buffer(channel->chan, channel->handle); |
| 898 | default: |
| 899 | return -EINVAL; |
| 900 | } |
| 901 | } |
| 902 | |
| 903 | static |
| 904 | int lttng_channel_release(int objd) |
| 905 | { |
| 906 | struct lttng_channel *channel = objd_private(objd); |
| 907 | |
| 908 | if (channel) |
| 909 | return lttng_ust_objd_unref(channel->session->objd, 0); |
| 910 | return 0; |
| 911 | } |
| 912 | |
| 913 | static const struct lttng_ust_objd_ops lttng_channel_ops = { |
| 914 | .release = lttng_channel_release, |
| 915 | .cmd = lttng_channel_cmd, |
| 916 | }; |
| 917 | |
| 918 | /** |
| 919 | * lttng_enabler_cmd - lttng control through object descriptors |
| 920 | * |
| 921 | * @objd: the object descriptor |
| 922 | * @cmd: the command |
| 923 | * @arg: command arg |
| 924 | * @uargs: UST arguments (internal) |
| 925 | * @owner: objd owner |
| 926 | * |
| 927 | * This object descriptor implements lttng commands: |
| 928 | * LTTNG_UST_CONTEXT |
| 929 | * Prepend a context field to each record of events of this |
| 930 | * enabler. |
| 931 | * LTTNG_UST_ENABLE |
| 932 | * Enable recording for this enabler |
| 933 | * LTTNG_UST_DISABLE |
| 934 | * Disable recording for this enabler |
| 935 | * LTTNG_UST_FILTER |
| 936 | * Attach a filter to an enabler. |
| 937 | * LTTNG_UST_EXCLUSION |
| 938 | * Attach exclusions to an enabler. |
| 939 | */ |
| 940 | static |
| 941 | long lttng_enabler_cmd(int objd, unsigned int cmd, unsigned long arg, |
| 942 | union ust_args *uargs, void *owner) |
| 943 | { |
| 944 | struct lttng_enabler *enabler = objd_private(objd); |
| 945 | |
| 946 | switch (cmd) { |
| 947 | case LTTNG_UST_CONTEXT: |
| 948 | return lttng_enabler_attach_context(enabler, |
| 949 | (struct lttng_ust_context *) arg); |
| 950 | case LTTNG_UST_ENABLE: |
| 951 | return lttng_enabler_enable(enabler); |
| 952 | case LTTNG_UST_DISABLE: |
| 953 | return lttng_enabler_disable(enabler); |
| 954 | case LTTNG_UST_FILTER: |
| 955 | { |
| 956 | int ret; |
| 957 | |
| 958 | ret = lttng_enabler_attach_bytecode(enabler, |
| 959 | (struct lttng_ust_filter_bytecode_node *) arg); |
| 960 | if (ret) |
| 961 | return ret; |
| 962 | return 0; |
| 963 | } |
| 964 | case LTTNG_UST_EXCLUSION: |
| 965 | { |
| 966 | return lttng_enabler_attach_exclusion(enabler, |
| 967 | (struct lttng_ust_excluder_node *) arg); |
| 968 | } |
| 969 | default: |
| 970 | return -EINVAL; |
| 971 | } |
| 972 | } |
| 973 | |
| 974 | static |
| 975 | int lttng_enabler_release(int objd) |
| 976 | { |
| 977 | struct lttng_enabler *enabler = objd_private(objd); |
| 978 | |
| 979 | if (enabler) |
| 980 | return lttng_ust_objd_unref(enabler->chan->objd, 0); |
| 981 | return 0; |
| 982 | } |
| 983 | |
| 984 | static const struct lttng_ust_objd_ops lttng_enabler_ops = { |
| 985 | .release = lttng_enabler_release, |
| 986 | .cmd = lttng_enabler_cmd, |
| 987 | }; |
| 988 | |
| 989 | void lttng_ust_abi_exit(void) |
| 990 | { |
| 991 | lttng_ust_abi_close_in_progress = 1; |
| 992 | ust_lock_nocheck(); |
| 993 | objd_table_destroy(); |
| 994 | ust_unlock(); |
| 995 | lttng_ust_abi_close_in_progress = 0; |
| 996 | } |