| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License, version 2 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along |
| 14 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 15 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _LGPL_SOURCE |
| 19 | #include <fcntl.h> |
| 20 | #include <stdlib.h> |
| 21 | #include <stdio.h> |
| 22 | #include <string.h> |
| 23 | #include <unistd.h> |
| 24 | #include <inttypes.h> |
| 25 | |
| 26 | #include <common/common.h> |
| 27 | #include <common/kernel-ctl/kernel-ctl.h> |
| 28 | #include <common/kernel-ctl/kernel-ioctl.h> |
| 29 | #include <common/sessiond-comm/sessiond-comm.h> |
| 30 | |
| 31 | #include "consumer.h" |
| 32 | #include "kernel.h" |
| 33 | #include "kernel-consumer.h" |
| 34 | #include "kern-modules.h" |
| 35 | #include "utils.h" |
| 36 | #include "rotate.h" |
| 37 | |
| 38 | /* |
| 39 | * Key used to reference a channel between the sessiond and the consumer. This |
| 40 | * is only read and updated with the session_list lock held. |
| 41 | */ |
| 42 | static uint64_t next_kernel_channel_key; |
| 43 | |
| 44 | /* |
| 45 | * Add context on a kernel channel. |
| 46 | * |
| 47 | * Assumes the ownership of ctx. |
| 48 | */ |
| 49 | int kernel_add_channel_context(struct ltt_kernel_channel *chan, |
| 50 | struct ltt_kernel_context *ctx) |
| 51 | { |
| 52 | int ret; |
| 53 | |
| 54 | assert(chan); |
| 55 | assert(ctx); |
| 56 | |
| 57 | DBG("Adding context to channel %s", chan->channel->name); |
| 58 | ret = kernctl_add_context(chan->fd, &ctx->ctx); |
| 59 | if (ret < 0) { |
| 60 | switch (-ret) { |
| 61 | case ENOSYS: |
| 62 | /* Exists but not available for this kernel */ |
| 63 | ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE; |
| 64 | goto error; |
| 65 | case EEXIST: |
| 66 | /* If EEXIST, we just ignore the error */ |
| 67 | ret = 0; |
| 68 | goto end; |
| 69 | default: |
| 70 | PERROR("add context ioctl"); |
| 71 | ret = LTTNG_ERR_KERN_CONTEXT_FAIL; |
| 72 | goto error; |
| 73 | } |
| 74 | } |
| 75 | ret = 0; |
| 76 | |
| 77 | end: |
| 78 | cds_list_add_tail(&ctx->list, &chan->ctx_list); |
| 79 | ctx->in_list = true; |
| 80 | ctx = NULL; |
| 81 | error: |
| 82 | if (ctx) { |
| 83 | trace_kernel_destroy_context(ctx); |
| 84 | } |
| 85 | return ret; |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * Create a new kernel session, register it to the kernel tracer and add it to |
| 90 | * the session daemon session. |
| 91 | */ |
| 92 | int kernel_create_session(struct ltt_session *session, int tracer_fd) |
| 93 | { |
| 94 | int ret; |
| 95 | struct ltt_kernel_session *lks; |
| 96 | |
| 97 | assert(session); |
| 98 | |
| 99 | /* Allocate data structure */ |
| 100 | lks = trace_kernel_create_session(); |
| 101 | if (lks == NULL) { |
| 102 | ret = -1; |
| 103 | goto error; |
| 104 | } |
| 105 | |
| 106 | /* Kernel tracer session creation */ |
| 107 | ret = kernctl_create_session(tracer_fd); |
| 108 | if (ret < 0) { |
| 109 | PERROR("ioctl kernel create session"); |
| 110 | goto error; |
| 111 | } |
| 112 | |
| 113 | lks->fd = ret; |
| 114 | /* Prevent fd duplication after execlp() */ |
| 115 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 116 | if (ret < 0) { |
| 117 | PERROR("fcntl session fd"); |
| 118 | } |
| 119 | |
| 120 | lks->id = session->id; |
| 121 | lks->consumer_fds_sent = 0; |
| 122 | session->kernel_session = lks; |
| 123 | |
| 124 | DBG("Kernel session created (fd: %d)", lks->fd); |
| 125 | |
| 126 | return 0; |
| 127 | |
| 128 | error: |
| 129 | if (lks) { |
| 130 | trace_kernel_destroy_session(lks); |
| 131 | } |
| 132 | return ret; |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * Create a kernel channel, register it to the kernel tracer and add it to the |
| 137 | * kernel session. |
| 138 | */ |
| 139 | int kernel_create_channel(struct ltt_kernel_session *session, |
| 140 | struct lttng_channel *chan) |
| 141 | { |
| 142 | int ret; |
| 143 | struct ltt_kernel_channel *lkc; |
| 144 | |
| 145 | assert(session); |
| 146 | assert(chan); |
| 147 | |
| 148 | /* Allocate kernel channel */ |
| 149 | lkc = trace_kernel_create_channel(chan); |
| 150 | if (lkc == NULL) { |
| 151 | goto error; |
| 152 | } |
| 153 | |
| 154 | DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d", |
| 155 | chan->name, lkc->channel->attr.overwrite, |
| 156 | lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf, |
| 157 | lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval, |
| 158 | lkc->channel->attr.live_timer_interval, lkc->channel->attr.output); |
| 159 | |
| 160 | /* Kernel tracer channel creation */ |
| 161 | ret = kernctl_create_channel(session->fd, &lkc->channel->attr); |
| 162 | if (ret < 0) { |
| 163 | PERROR("ioctl kernel create channel"); |
| 164 | goto error; |
| 165 | } |
| 166 | |
| 167 | /* Setup the channel fd */ |
| 168 | lkc->fd = ret; |
| 169 | /* Prevent fd duplication after execlp() */ |
| 170 | ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC); |
| 171 | if (ret < 0) { |
| 172 | PERROR("fcntl session fd"); |
| 173 | } |
| 174 | |
| 175 | /* Add channel to session */ |
| 176 | cds_list_add(&lkc->list, &session->channel_list.head); |
| 177 | session->channel_count++; |
| 178 | lkc->session = session; |
| 179 | lkc->key = ++next_kernel_channel_key; |
| 180 | |
| 181 | DBG("Kernel channel %s created (fd: %d, key: %" PRIu64 ")", |
| 182 | lkc->channel->name, lkc->fd, lkc->key); |
| 183 | |
| 184 | return 0; |
| 185 | |
| 186 | error: |
| 187 | if (lkc) { |
| 188 | free(lkc->channel); |
| 189 | free(lkc); |
| 190 | } |
| 191 | return -1; |
| 192 | } |
| 193 | |
| 194 | /* |
| 195 | * Create a kernel event, enable it to the kernel tracer and add it to the |
| 196 | * channel event list of the kernel session. |
| 197 | * We own filter_expression and filter. |
| 198 | */ |
| 199 | int kernel_create_event(struct lttng_event *ev, |
| 200 | struct ltt_kernel_channel *channel, |
| 201 | char *filter_expression, |
| 202 | struct lttng_filter_bytecode *filter) |
| 203 | { |
| 204 | int err, fd; |
| 205 | enum lttng_error_code ret; |
| 206 | struct ltt_kernel_event *event; |
| 207 | |
| 208 | assert(ev); |
| 209 | assert(channel); |
| 210 | |
| 211 | /* We pass ownership of filter_expression and filter */ |
| 212 | ret = trace_kernel_create_event(ev, filter_expression, |
| 213 | filter, &event); |
| 214 | if (ret != LTTNG_OK) { |
| 215 | goto error; |
| 216 | } |
| 217 | |
| 218 | fd = kernctl_create_event(channel->fd, event->event); |
| 219 | if (fd < 0) { |
| 220 | switch (-fd) { |
| 221 | case EEXIST: |
| 222 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 223 | break; |
| 224 | case ENOSYS: |
| 225 | WARN("Event type not implemented"); |
| 226 | ret = LTTNG_ERR_KERN_EVENT_ENOSYS; |
| 227 | break; |
| 228 | case ENOENT: |
| 229 | WARN("Event %s not found!", ev->name); |
| 230 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 231 | break; |
| 232 | default: |
| 233 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 234 | PERROR("create event ioctl"); |
| 235 | } |
| 236 | goto free_event; |
| 237 | } |
| 238 | |
| 239 | event->type = ev->type; |
| 240 | event->fd = fd; |
| 241 | /* Prevent fd duplication after execlp() */ |
| 242 | err = fcntl(event->fd, F_SETFD, FD_CLOEXEC); |
| 243 | if (err < 0) { |
| 244 | PERROR("fcntl session fd"); |
| 245 | } |
| 246 | |
| 247 | if (filter) { |
| 248 | err = kernctl_filter(event->fd, filter); |
| 249 | if (err < 0) { |
| 250 | switch (-err) { |
| 251 | case ENOMEM: |
| 252 | ret = LTTNG_ERR_FILTER_NOMEM; |
| 253 | break; |
| 254 | default: |
| 255 | ret = LTTNG_ERR_FILTER_INVAL; |
| 256 | break; |
| 257 | } |
| 258 | goto filter_error; |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | err = kernctl_enable(event->fd); |
| 263 | if (err < 0) { |
| 264 | switch (-err) { |
| 265 | case EEXIST: |
| 266 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 267 | break; |
| 268 | default: |
| 269 | PERROR("enable kernel event"); |
| 270 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 271 | break; |
| 272 | } |
| 273 | goto enable_error; |
| 274 | } |
| 275 | |
| 276 | /* Add event to event list */ |
| 277 | cds_list_add(&event->list, &channel->events_list.head); |
| 278 | channel->event_count++; |
| 279 | |
| 280 | DBG("Event %s created (fd: %d)", ev->name, event->fd); |
| 281 | |
| 282 | return 0; |
| 283 | |
| 284 | enable_error: |
| 285 | filter_error: |
| 286 | { |
| 287 | int closeret; |
| 288 | |
| 289 | closeret = close(event->fd); |
| 290 | if (closeret) { |
| 291 | PERROR("close event fd"); |
| 292 | } |
| 293 | } |
| 294 | free_event: |
| 295 | free(event); |
| 296 | error: |
| 297 | return ret; |
| 298 | } |
| 299 | |
| 300 | /* |
| 301 | * Disable a kernel channel. |
| 302 | */ |
| 303 | int kernel_disable_channel(struct ltt_kernel_channel *chan) |
| 304 | { |
| 305 | int ret; |
| 306 | |
| 307 | assert(chan); |
| 308 | |
| 309 | ret = kernctl_disable(chan->fd); |
| 310 | if (ret < 0) { |
| 311 | PERROR("disable chan ioctl"); |
| 312 | goto error; |
| 313 | } |
| 314 | |
| 315 | chan->enabled = 0; |
| 316 | DBG("Kernel channel %s disabled (fd: %d, key: %" PRIu64 ")", |
| 317 | chan->channel->name, chan->fd, chan->key); |
| 318 | |
| 319 | return 0; |
| 320 | |
| 321 | error: |
| 322 | return ret; |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Enable a kernel channel. |
| 327 | */ |
| 328 | int kernel_enable_channel(struct ltt_kernel_channel *chan) |
| 329 | { |
| 330 | int ret; |
| 331 | |
| 332 | assert(chan); |
| 333 | |
| 334 | ret = kernctl_enable(chan->fd); |
| 335 | if (ret < 0 && ret != -EEXIST) { |
| 336 | PERROR("Enable kernel chan"); |
| 337 | goto error; |
| 338 | } |
| 339 | |
| 340 | chan->enabled = 1; |
| 341 | DBG("Kernel channel %s enabled (fd: %d, key: %" PRIu64 ")", |
| 342 | chan->channel->name, chan->fd, chan->key); |
| 343 | |
| 344 | return 0; |
| 345 | |
| 346 | error: |
| 347 | return ret; |
| 348 | } |
| 349 | |
| 350 | /* |
| 351 | * Enable a kernel event. |
| 352 | */ |
| 353 | int kernel_enable_event(struct ltt_kernel_event *event) |
| 354 | { |
| 355 | int ret; |
| 356 | |
| 357 | assert(event); |
| 358 | |
| 359 | ret = kernctl_enable(event->fd); |
| 360 | if (ret < 0) { |
| 361 | switch (-ret) { |
| 362 | case EEXIST: |
| 363 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 364 | break; |
| 365 | default: |
| 366 | PERROR("enable kernel event"); |
| 367 | break; |
| 368 | } |
| 369 | goto error; |
| 370 | } |
| 371 | |
| 372 | event->enabled = 1; |
| 373 | DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd); |
| 374 | |
| 375 | return 0; |
| 376 | |
| 377 | error: |
| 378 | return ret; |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * Disable a kernel event. |
| 383 | */ |
| 384 | int kernel_disable_event(struct ltt_kernel_event *event) |
| 385 | { |
| 386 | int ret; |
| 387 | |
| 388 | assert(event); |
| 389 | |
| 390 | ret = kernctl_disable(event->fd); |
| 391 | if (ret < 0) { |
| 392 | switch (-ret) { |
| 393 | case EEXIST: |
| 394 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 395 | break; |
| 396 | default: |
| 397 | PERROR("disable kernel event"); |
| 398 | break; |
| 399 | } |
| 400 | goto error; |
| 401 | } |
| 402 | |
| 403 | event->enabled = 0; |
| 404 | DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd); |
| 405 | |
| 406 | return 0; |
| 407 | |
| 408 | error: |
| 409 | return ret; |
| 410 | } |
| 411 | |
| 412 | |
| 413 | int kernel_track_pid(struct ltt_kernel_session *session, int pid) |
| 414 | { |
| 415 | int ret; |
| 416 | |
| 417 | DBG("Kernel track PID %d for session id %" PRIu64 ".", |
| 418 | pid, session->id); |
| 419 | ret = kernctl_track_pid(session->fd, pid); |
| 420 | if (!ret) { |
| 421 | return LTTNG_OK; |
| 422 | } |
| 423 | switch (-ret) { |
| 424 | case EINVAL: |
| 425 | return LTTNG_ERR_INVALID; |
| 426 | case ENOMEM: |
| 427 | return LTTNG_ERR_NOMEM; |
| 428 | case EEXIST: |
| 429 | return LTTNG_ERR_PID_TRACKED; |
| 430 | default: |
| 431 | return LTTNG_ERR_UNK; |
| 432 | } |
| 433 | } |
| 434 | |
| 435 | int kernel_untrack_pid(struct ltt_kernel_session *session, int pid) |
| 436 | { |
| 437 | int ret; |
| 438 | |
| 439 | DBG("Kernel untrack PID %d for session id %" PRIu64 ".", |
| 440 | pid, session->id); |
| 441 | ret = kernctl_untrack_pid(session->fd, pid); |
| 442 | if (!ret) { |
| 443 | return LTTNG_OK; |
| 444 | } |
| 445 | switch (-ret) { |
| 446 | case EINVAL: |
| 447 | return LTTNG_ERR_INVALID; |
| 448 | case ENOMEM: |
| 449 | return LTTNG_ERR_NOMEM; |
| 450 | case ENOENT: |
| 451 | return LTTNG_ERR_PID_NOT_TRACKED; |
| 452 | default: |
| 453 | return LTTNG_ERR_UNK; |
| 454 | } |
| 455 | } |
| 456 | |
| 457 | ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session, |
| 458 | int **_pids) |
| 459 | { |
| 460 | int fd, ret; |
| 461 | int pid; |
| 462 | ssize_t nbmem, count = 0; |
| 463 | FILE *fp; |
| 464 | int *pids; |
| 465 | |
| 466 | fd = kernctl_list_tracker_pids(session->fd); |
| 467 | if (fd < 0) { |
| 468 | PERROR("kernel tracker pids list"); |
| 469 | goto error; |
| 470 | } |
| 471 | |
| 472 | fp = fdopen(fd, "r"); |
| 473 | if (fp == NULL) { |
| 474 | PERROR("kernel tracker pids list fdopen"); |
| 475 | goto error_fp; |
| 476 | } |
| 477 | |
| 478 | nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE; |
| 479 | pids = zmalloc(sizeof(*pids) * nbmem); |
| 480 | if (pids == NULL) { |
| 481 | PERROR("alloc list pids"); |
| 482 | count = -ENOMEM; |
| 483 | goto end; |
| 484 | } |
| 485 | |
| 486 | while (fscanf(fp, "process { pid = %u; };\n", &pid) == 1) { |
| 487 | if (count >= nbmem) { |
| 488 | int *new_pids; |
| 489 | size_t new_nbmem; |
| 490 | |
| 491 | new_nbmem = nbmem << 1; |
| 492 | DBG("Reallocating pids list from %zu to %zu entries", |
| 493 | nbmem, new_nbmem); |
| 494 | new_pids = realloc(pids, new_nbmem * sizeof(*new_pids)); |
| 495 | if (new_pids == NULL) { |
| 496 | PERROR("realloc list events"); |
| 497 | free(pids); |
| 498 | count = -ENOMEM; |
| 499 | goto end; |
| 500 | } |
| 501 | /* Zero the new memory */ |
| 502 | memset(new_pids + nbmem, 0, |
| 503 | (new_nbmem - nbmem) * sizeof(*new_pids)); |
| 504 | nbmem = new_nbmem; |
| 505 | pids = new_pids; |
| 506 | } |
| 507 | pids[count++] = pid; |
| 508 | } |
| 509 | |
| 510 | *_pids = pids; |
| 511 | DBG("Kernel list tracker pids done (%zd pids)", count); |
| 512 | end: |
| 513 | ret = fclose(fp); /* closes both fp and fd */ |
| 514 | if (ret) { |
| 515 | PERROR("fclose"); |
| 516 | } |
| 517 | return count; |
| 518 | |
| 519 | error_fp: |
| 520 | ret = close(fd); |
| 521 | if (ret) { |
| 522 | PERROR("close"); |
| 523 | } |
| 524 | error: |
| 525 | return -1; |
| 526 | } |
| 527 | |
| 528 | /* |
| 529 | * Create kernel metadata, open from the kernel tracer and add it to the |
| 530 | * kernel session. |
| 531 | */ |
| 532 | int kernel_open_metadata(struct ltt_kernel_session *session) |
| 533 | { |
| 534 | int ret; |
| 535 | struct ltt_kernel_metadata *lkm = NULL; |
| 536 | |
| 537 | assert(session); |
| 538 | |
| 539 | /* Allocate kernel metadata */ |
| 540 | lkm = trace_kernel_create_metadata(); |
| 541 | if (lkm == NULL) { |
| 542 | goto error; |
| 543 | } |
| 544 | |
| 545 | /* Kernel tracer metadata creation */ |
| 546 | ret = kernctl_open_metadata(session->fd, &lkm->conf->attr); |
| 547 | if (ret < 0) { |
| 548 | goto error_open; |
| 549 | } |
| 550 | |
| 551 | lkm->fd = ret; |
| 552 | lkm->key = ++next_kernel_channel_key; |
| 553 | /* Prevent fd duplication after execlp() */ |
| 554 | ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC); |
| 555 | if (ret < 0) { |
| 556 | PERROR("fcntl session fd"); |
| 557 | } |
| 558 | |
| 559 | session->metadata = lkm; |
| 560 | |
| 561 | DBG("Kernel metadata opened (fd: %d)", lkm->fd); |
| 562 | |
| 563 | return 0; |
| 564 | |
| 565 | error_open: |
| 566 | trace_kernel_destroy_metadata(lkm); |
| 567 | error: |
| 568 | return -1; |
| 569 | } |
| 570 | |
| 571 | /* |
| 572 | * Start tracing session. |
| 573 | */ |
| 574 | int kernel_start_session(struct ltt_kernel_session *session) |
| 575 | { |
| 576 | int ret; |
| 577 | |
| 578 | assert(session); |
| 579 | |
| 580 | ret = kernctl_start_session(session->fd); |
| 581 | if (ret < 0) { |
| 582 | PERROR("ioctl start session"); |
| 583 | goto error; |
| 584 | } |
| 585 | |
| 586 | DBG("Kernel session started"); |
| 587 | |
| 588 | return 0; |
| 589 | |
| 590 | error: |
| 591 | return ret; |
| 592 | } |
| 593 | |
| 594 | /* |
| 595 | * Make a kernel wait to make sure in-flight probe have completed. |
| 596 | */ |
| 597 | void kernel_wait_quiescent(int fd) |
| 598 | { |
| 599 | int ret; |
| 600 | |
| 601 | DBG("Kernel quiescent wait on %d", fd); |
| 602 | |
| 603 | ret = kernctl_wait_quiescent(fd); |
| 604 | if (ret < 0) { |
| 605 | PERROR("wait quiescent ioctl"); |
| 606 | ERR("Kernel quiescent wait failed"); |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | /* |
| 611 | * Force flush buffer of metadata. |
| 612 | */ |
| 613 | int kernel_metadata_flush_buffer(int fd) |
| 614 | { |
| 615 | int ret; |
| 616 | |
| 617 | DBG("Kernel flushing metadata buffer on fd %d", fd); |
| 618 | |
| 619 | ret = kernctl_buffer_flush(fd); |
| 620 | if (ret < 0) { |
| 621 | ERR("Fail to flush metadata buffers %d (ret: %d)", fd, ret); |
| 622 | } |
| 623 | |
| 624 | return 0; |
| 625 | } |
| 626 | |
| 627 | /* |
| 628 | * Force flush buffer for channel. |
| 629 | */ |
| 630 | int kernel_flush_buffer(struct ltt_kernel_channel *channel) |
| 631 | { |
| 632 | int ret; |
| 633 | struct ltt_kernel_stream *stream; |
| 634 | |
| 635 | assert(channel); |
| 636 | |
| 637 | DBG("Flush buffer for channel %s", channel->channel->name); |
| 638 | |
| 639 | cds_list_for_each_entry(stream, &channel->stream_list.head, list) { |
| 640 | DBG("Flushing channel stream %d", stream->fd); |
| 641 | ret = kernctl_buffer_flush(stream->fd); |
| 642 | if (ret < 0) { |
| 643 | PERROR("ioctl"); |
| 644 | ERR("Fail to flush buffer for stream %d (ret: %d)", |
| 645 | stream->fd, ret); |
| 646 | } |
| 647 | } |
| 648 | |
| 649 | return 0; |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * Stop tracing session. |
| 654 | */ |
| 655 | int kernel_stop_session(struct ltt_kernel_session *session) |
| 656 | { |
| 657 | int ret; |
| 658 | |
| 659 | assert(session); |
| 660 | |
| 661 | ret = kernctl_stop_session(session->fd); |
| 662 | if (ret < 0) { |
| 663 | goto error; |
| 664 | } |
| 665 | |
| 666 | DBG("Kernel session stopped"); |
| 667 | |
| 668 | return 0; |
| 669 | |
| 670 | error: |
| 671 | return ret; |
| 672 | } |
| 673 | |
| 674 | /* |
| 675 | * Open stream of channel, register it to the kernel tracer and add it |
| 676 | * to the stream list of the channel. |
| 677 | * |
| 678 | * Note: given that the streams may appear in random order wrt CPU |
| 679 | * number (e.g. cpu hotplug), the index value of the stream number in |
| 680 | * the stream name is not necessarily linked to the CPU number. |
| 681 | * |
| 682 | * Return the number of created stream. Else, a negative value. |
| 683 | */ |
| 684 | int kernel_open_channel_stream(struct ltt_kernel_channel *channel) |
| 685 | { |
| 686 | int ret; |
| 687 | struct ltt_kernel_stream *lks; |
| 688 | |
| 689 | assert(channel); |
| 690 | |
| 691 | while ((ret = kernctl_create_stream(channel->fd)) >= 0) { |
| 692 | lks = trace_kernel_create_stream(channel->channel->name, |
| 693 | channel->stream_count); |
| 694 | if (lks == NULL) { |
| 695 | ret = close(ret); |
| 696 | if (ret) { |
| 697 | PERROR("close"); |
| 698 | } |
| 699 | goto error; |
| 700 | } |
| 701 | |
| 702 | lks->fd = ret; |
| 703 | /* Prevent fd duplication after execlp() */ |
| 704 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 705 | if (ret < 0) { |
| 706 | PERROR("fcntl session fd"); |
| 707 | } |
| 708 | |
| 709 | lks->tracefile_size = channel->channel->attr.tracefile_size; |
| 710 | lks->tracefile_count = channel->channel->attr.tracefile_count; |
| 711 | |
| 712 | /* Add stream to channel stream list */ |
| 713 | cds_list_add(&lks->list, &channel->stream_list.head); |
| 714 | channel->stream_count++; |
| 715 | |
| 716 | DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd, |
| 717 | lks->state); |
| 718 | } |
| 719 | |
| 720 | return channel->stream_count; |
| 721 | |
| 722 | error: |
| 723 | return -1; |
| 724 | } |
| 725 | |
| 726 | /* |
| 727 | * Open the metadata stream and set it to the kernel session. |
| 728 | */ |
| 729 | int kernel_open_metadata_stream(struct ltt_kernel_session *session) |
| 730 | { |
| 731 | int ret; |
| 732 | |
| 733 | assert(session); |
| 734 | |
| 735 | ret = kernctl_create_stream(session->metadata->fd); |
| 736 | if (ret < 0) { |
| 737 | PERROR("kernel create metadata stream"); |
| 738 | goto error; |
| 739 | } |
| 740 | |
| 741 | DBG("Kernel metadata stream created (fd: %d)", ret); |
| 742 | session->metadata_stream_fd = ret; |
| 743 | /* Prevent fd duplication after execlp() */ |
| 744 | ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC); |
| 745 | if (ret < 0) { |
| 746 | PERROR("fcntl session fd"); |
| 747 | } |
| 748 | |
| 749 | return 0; |
| 750 | |
| 751 | error: |
| 752 | return -1; |
| 753 | } |
| 754 | |
| 755 | /* |
| 756 | * Get the event list from the kernel tracer and return the number of elements. |
| 757 | */ |
| 758 | ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events) |
| 759 | { |
| 760 | int fd, ret; |
| 761 | char *event; |
| 762 | size_t nbmem, count = 0; |
| 763 | FILE *fp; |
| 764 | struct lttng_event *elist; |
| 765 | |
| 766 | assert(events); |
| 767 | |
| 768 | fd = kernctl_tracepoint_list(tracer_fd); |
| 769 | if (fd < 0) { |
| 770 | PERROR("kernel tracepoint list"); |
| 771 | goto error; |
| 772 | } |
| 773 | |
| 774 | fp = fdopen(fd, "r"); |
| 775 | if (fp == NULL) { |
| 776 | PERROR("kernel tracepoint list fdopen"); |
| 777 | goto error_fp; |
| 778 | } |
| 779 | |
| 780 | /* |
| 781 | * Init memory size counter |
| 782 | * See kernel-ctl.h for explanation of this value |
| 783 | */ |
| 784 | nbmem = KERNEL_EVENT_INIT_LIST_SIZE; |
| 785 | elist = zmalloc(sizeof(struct lttng_event) * nbmem); |
| 786 | if (elist == NULL) { |
| 787 | PERROR("alloc list events"); |
| 788 | count = -ENOMEM; |
| 789 | goto end; |
| 790 | } |
| 791 | |
| 792 | while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) { |
| 793 | if (count >= nbmem) { |
| 794 | struct lttng_event *new_elist; |
| 795 | size_t new_nbmem; |
| 796 | |
| 797 | new_nbmem = nbmem << 1; |
| 798 | DBG("Reallocating event list from %zu to %zu bytes", |
| 799 | nbmem, new_nbmem); |
| 800 | new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event)); |
| 801 | if (new_elist == NULL) { |
| 802 | PERROR("realloc list events"); |
| 803 | free(event); |
| 804 | free(elist); |
| 805 | count = -ENOMEM; |
| 806 | goto end; |
| 807 | } |
| 808 | /* Zero the new memory */ |
| 809 | memset(new_elist + nbmem, 0, |
| 810 | (new_nbmem - nbmem) * sizeof(struct lttng_event)); |
| 811 | nbmem = new_nbmem; |
| 812 | elist = new_elist; |
| 813 | } |
| 814 | strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN); |
| 815 | elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 816 | elist[count].enabled = -1; |
| 817 | count++; |
| 818 | free(event); |
| 819 | } |
| 820 | |
| 821 | *events = elist; |
| 822 | DBG("Kernel list events done (%zu events)", count); |
| 823 | end: |
| 824 | ret = fclose(fp); /* closes both fp and fd */ |
| 825 | if (ret) { |
| 826 | PERROR("fclose"); |
| 827 | } |
| 828 | return count; |
| 829 | |
| 830 | error_fp: |
| 831 | ret = close(fd); |
| 832 | if (ret) { |
| 833 | PERROR("close"); |
| 834 | } |
| 835 | error: |
| 836 | return -1; |
| 837 | } |
| 838 | |
| 839 | /* |
| 840 | * Get kernel version and validate it. |
| 841 | */ |
| 842 | int kernel_validate_version(int tracer_fd, |
| 843 | struct lttng_kernel_tracer_version *version, |
| 844 | struct lttng_kernel_tracer_abi_version *abi_version) |
| 845 | { |
| 846 | int ret; |
| 847 | |
| 848 | ret = kernctl_tracer_version(tracer_fd, version); |
| 849 | if (ret < 0) { |
| 850 | ERR("Failed to retrieve the lttng-modules version"); |
| 851 | goto error; |
| 852 | } |
| 853 | |
| 854 | /* Validate version */ |
| 855 | if (version->major != VERSION_MAJOR) { |
| 856 | ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)", |
| 857 | version->major, VERSION_MAJOR); |
| 858 | goto error_version; |
| 859 | } |
| 860 | ret = kernctl_tracer_abi_version(tracer_fd, abi_version); |
| 861 | if (ret < 0) { |
| 862 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 863 | goto error; |
| 864 | } |
| 865 | if (abi_version->major != LTTNG_MODULES_ABI_MAJOR_VERSION) { |
| 866 | ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)", |
| 867 | abi_version->major, abi_version->minor, |
| 868 | LTTNG_MODULES_ABI_MAJOR_VERSION); |
| 869 | goto error; |
| 870 | } |
| 871 | DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)", |
| 872 | version->major, version->minor, |
| 873 | abi_version->major, abi_version->minor); |
| 874 | return 0; |
| 875 | |
| 876 | error_version: |
| 877 | ret = -1; |
| 878 | |
| 879 | error: |
| 880 | ERR("Kernel tracer version check failed; kernel tracing will not be available"); |
| 881 | return ret; |
| 882 | } |
| 883 | |
| 884 | /* |
| 885 | * Kernel work-arounds called at the start of sessiond main(). |
| 886 | */ |
| 887 | int init_kernel_workarounds(void) |
| 888 | { |
| 889 | int ret; |
| 890 | FILE *fp; |
| 891 | |
| 892 | /* |
| 893 | * boot_id needs to be read once before being used concurrently |
| 894 | * to deal with a Linux kernel race. A fix is proposed for |
| 895 | * upstream, but the work-around is needed for older kernels. |
| 896 | */ |
| 897 | fp = fopen("/proc/sys/kernel/random/boot_id", "r"); |
| 898 | if (!fp) { |
| 899 | goto end_boot_id; |
| 900 | } |
| 901 | while (!feof(fp)) { |
| 902 | char buf[37] = ""; |
| 903 | |
| 904 | ret = fread(buf, 1, sizeof(buf), fp); |
| 905 | if (ret < 0) { |
| 906 | /* Ignore error, we don't really care */ |
| 907 | } |
| 908 | } |
| 909 | ret = fclose(fp); |
| 910 | if (ret) { |
| 911 | PERROR("fclose"); |
| 912 | } |
| 913 | end_boot_id: |
| 914 | return 0; |
| 915 | } |
| 916 | |
| 917 | /* |
| 918 | * Complete teardown of a kernel session. |
| 919 | */ |
| 920 | void kernel_destroy_session(struct ltt_kernel_session *ksess) |
| 921 | { |
| 922 | if (ksess == NULL) { |
| 923 | DBG3("No kernel session when tearing down session"); |
| 924 | return; |
| 925 | } |
| 926 | |
| 927 | DBG("Tearing down kernel session"); |
| 928 | |
| 929 | /* |
| 930 | * Destroy channels on the consumer if at least one FD has been sent and we |
| 931 | * are in no output mode because the streams are in *no* monitor mode so we |
| 932 | * have to send a command to clean them up or else they leaked. |
| 933 | */ |
| 934 | if (!ksess->output_traces && ksess->consumer_fds_sent) { |
| 935 | int ret; |
| 936 | struct consumer_socket *socket; |
| 937 | struct lttng_ht_iter iter; |
| 938 | |
| 939 | /* For each consumer socket. */ |
| 940 | rcu_read_lock(); |
| 941 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 942 | socket, node.node) { |
| 943 | struct ltt_kernel_channel *chan; |
| 944 | |
| 945 | /* For each channel, ask the consumer to destroy it. */ |
| 946 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 947 | ret = kernel_consumer_destroy_channel(socket, chan); |
| 948 | if (ret < 0) { |
| 949 | /* Consumer is probably dead. Use next socket. */ |
| 950 | continue; |
| 951 | } |
| 952 | } |
| 953 | } |
| 954 | rcu_read_unlock(); |
| 955 | } |
| 956 | |
| 957 | /* Close any relayd session */ |
| 958 | consumer_output_send_destroy_relayd(ksess->consumer); |
| 959 | |
| 960 | trace_kernel_destroy_session(ksess); |
| 961 | } |
| 962 | |
| 963 | /* |
| 964 | * Destroy a kernel channel object. It does not do anything on the tracer side. |
| 965 | */ |
| 966 | void kernel_destroy_channel(struct ltt_kernel_channel *kchan) |
| 967 | { |
| 968 | struct ltt_kernel_session *ksess = NULL; |
| 969 | |
| 970 | assert(kchan); |
| 971 | assert(kchan->channel); |
| 972 | |
| 973 | DBG3("Kernel destroy channel %s", kchan->channel->name); |
| 974 | |
| 975 | /* Update channel count of associated session. */ |
| 976 | if (kchan->session) { |
| 977 | /* Keep pointer reference so we can update it after the destroy. */ |
| 978 | ksess = kchan->session; |
| 979 | } |
| 980 | |
| 981 | trace_kernel_destroy_channel(kchan); |
| 982 | |
| 983 | /* |
| 984 | * At this point the kernel channel is not visible anymore. This is safe |
| 985 | * since in order to work on a visible kernel session, the tracing session |
| 986 | * lock (ltt_session.lock) MUST be acquired. |
| 987 | */ |
| 988 | if (ksess) { |
| 989 | ksess->channel_count--; |
| 990 | } |
| 991 | } |
| 992 | |
| 993 | /* |
| 994 | * Take a snapshot for a given kernel session. |
| 995 | * |
| 996 | * Return 0 on success or else return a LTTNG_ERR code. |
| 997 | */ |
| 998 | int kernel_snapshot_record(struct ltt_kernel_session *ksess, |
| 999 | struct snapshot_output *output, int wait, |
| 1000 | uint64_t nb_packets_per_stream) |
| 1001 | { |
| 1002 | int err, ret, saved_metadata_fd; |
| 1003 | struct consumer_socket *socket; |
| 1004 | struct lttng_ht_iter iter; |
| 1005 | struct ltt_kernel_metadata *saved_metadata; |
| 1006 | struct ltt_session *session; |
| 1007 | uint64_t trace_archive_id; |
| 1008 | |
| 1009 | assert(ksess); |
| 1010 | assert(ksess->consumer); |
| 1011 | assert(output); |
| 1012 | |
| 1013 | DBG("Kernel snapshot record started"); |
| 1014 | |
| 1015 | session = session_find_by_id(ksess->id); |
| 1016 | assert(session); |
| 1017 | assert(pthread_mutex_trylock(&session->lock)); |
| 1018 | assert(session_trylock_list()); |
| 1019 | trace_archive_id = session->current_archive_id; |
| 1020 | |
| 1021 | /* Save current metadata since the following calls will change it. */ |
| 1022 | saved_metadata = ksess->metadata; |
| 1023 | saved_metadata_fd = ksess->metadata_stream_fd; |
| 1024 | |
| 1025 | rcu_read_lock(); |
| 1026 | |
| 1027 | ret = kernel_open_metadata(ksess); |
| 1028 | if (ret < 0) { |
| 1029 | ret = LTTNG_ERR_KERN_META_FAIL; |
| 1030 | goto error; |
| 1031 | } |
| 1032 | |
| 1033 | ret = kernel_open_metadata_stream(ksess); |
| 1034 | if (ret < 0) { |
| 1035 | ret = LTTNG_ERR_KERN_META_FAIL; |
| 1036 | goto error_open_stream; |
| 1037 | } |
| 1038 | |
| 1039 | /* Send metadata to consumer and snapshot everything. */ |
| 1040 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1041 | socket, node.node) { |
| 1042 | struct consumer_output *saved_output; |
| 1043 | struct ltt_kernel_channel *chan; |
| 1044 | |
| 1045 | /* |
| 1046 | * Temporarly switch consumer output for our snapshot output. As long |
| 1047 | * as the session lock is taken, this is safe. |
| 1048 | */ |
| 1049 | saved_output = ksess->consumer; |
| 1050 | ksess->consumer = output->consumer; |
| 1051 | |
| 1052 | pthread_mutex_lock(socket->lock); |
| 1053 | /* This stream must not be monitored by the consumer. */ |
| 1054 | ret = kernel_consumer_add_metadata(socket, ksess, 0); |
| 1055 | pthread_mutex_unlock(socket->lock); |
| 1056 | /* Put back the saved consumer output into the session. */ |
| 1057 | ksess->consumer = saved_output; |
| 1058 | if (ret < 0) { |
| 1059 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1060 | goto error_consumer; |
| 1061 | } |
| 1062 | |
| 1063 | /* For each channel, ask the consumer to snapshot it. */ |
| 1064 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1065 | ret = consumer_snapshot_channel(socket, chan->key, output, 0, |
| 1066 | ksess->uid, ksess->gid, |
| 1067 | DEFAULT_KERNEL_TRACE_DIR, wait, |
| 1068 | nb_packets_per_stream, |
| 1069 | trace_archive_id); |
| 1070 | if (ret < 0) { |
| 1071 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1072 | (void) kernel_consumer_destroy_metadata(socket, |
| 1073 | ksess->metadata); |
| 1074 | goto error_consumer; |
| 1075 | } |
| 1076 | } |
| 1077 | |
| 1078 | /* Snapshot metadata, */ |
| 1079 | ret = consumer_snapshot_channel(socket, ksess->metadata->key, output, |
| 1080 | 1, ksess->uid, ksess->gid, |
| 1081 | DEFAULT_KERNEL_TRACE_DIR, wait, 0, |
| 1082 | trace_archive_id); |
| 1083 | if (ret < 0) { |
| 1084 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1085 | goto error_consumer; |
| 1086 | } |
| 1087 | |
| 1088 | /* |
| 1089 | * The metadata snapshot is done, ask the consumer to destroy it since |
| 1090 | * it's not monitored on the consumer side. |
| 1091 | */ |
| 1092 | (void) kernel_consumer_destroy_metadata(socket, ksess->metadata); |
| 1093 | } |
| 1094 | |
| 1095 | ret = LTTNG_OK; |
| 1096 | |
| 1097 | error_consumer: |
| 1098 | /* Close newly opened metadata stream. It's now on the consumer side. */ |
| 1099 | err = close(ksess->metadata_stream_fd); |
| 1100 | if (err < 0) { |
| 1101 | PERROR("close snapshot kernel"); |
| 1102 | } |
| 1103 | |
| 1104 | error_open_stream: |
| 1105 | trace_kernel_destroy_metadata(ksess->metadata); |
| 1106 | error: |
| 1107 | /* Restore metadata state.*/ |
| 1108 | ksess->metadata = saved_metadata; |
| 1109 | ksess->metadata_stream_fd = saved_metadata_fd; |
| 1110 | |
| 1111 | rcu_read_unlock(); |
| 1112 | return ret; |
| 1113 | } |
| 1114 | |
| 1115 | /* |
| 1116 | * Get the syscall mask array from the kernel tracer. |
| 1117 | * |
| 1118 | * Return 0 on success else a negative value. In both case, syscall_mask should |
| 1119 | * be freed. |
| 1120 | */ |
| 1121 | int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits) |
| 1122 | { |
| 1123 | assert(syscall_mask); |
| 1124 | assert(nr_bits); |
| 1125 | |
| 1126 | return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits); |
| 1127 | } |
| 1128 | |
| 1129 | /* |
| 1130 | * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi |
| 1131 | * version number. |
| 1132 | * |
| 1133 | * Return 1 on success, 0 when feature is not supported, negative value in case |
| 1134 | * of errors. |
| 1135 | */ |
| 1136 | int kernel_supports_ring_buffer_snapshot_sample_positions(int tracer_fd) |
| 1137 | { |
| 1138 | int ret = 0; // Not supported by default |
| 1139 | struct lttng_kernel_tracer_abi_version abi; |
| 1140 | |
| 1141 | ret = kernctl_tracer_abi_version(tracer_fd, &abi); |
| 1142 | if (ret < 0) { |
| 1143 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 1144 | goto error; |
| 1145 | } |
| 1146 | |
| 1147 | /* |
| 1148 | * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3 |
| 1149 | */ |
| 1150 | if (abi.major >= 2 && abi.minor >= 3) { |
| 1151 | /* Supported */ |
| 1152 | ret = 1; |
| 1153 | } else { |
| 1154 | /* Not supported */ |
| 1155 | ret = 0; |
| 1156 | } |
| 1157 | error: |
| 1158 | return ret; |
| 1159 | } |
| 1160 | |
| 1161 | /* |
| 1162 | * Rotate a kernel session. |
| 1163 | * |
| 1164 | * Return 0 on success or else return a LTTNG_ERR code. |
| 1165 | */ |
| 1166 | int kernel_rotate_session(struct ltt_session *session) |
| 1167 | { |
| 1168 | int ret; |
| 1169 | struct consumer_socket *socket; |
| 1170 | struct lttng_ht_iter iter; |
| 1171 | struct ltt_kernel_session *ksess = session->kernel_session; |
| 1172 | |
| 1173 | assert(ksess); |
| 1174 | assert(ksess->consumer); |
| 1175 | |
| 1176 | DBG("Rotate kernel session %s started (session %" PRIu64 ")", |
| 1177 | session->name, session->id); |
| 1178 | |
| 1179 | rcu_read_lock(); |
| 1180 | |
| 1181 | /* |
| 1182 | * Note that this loop will end after one iteration given that there is |
| 1183 | * only one kernel consumer. |
| 1184 | */ |
| 1185 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1186 | socket, node.node) { |
| 1187 | struct ltt_kernel_channel *chan; |
| 1188 | |
| 1189 | /* |
| 1190 | * Account the metadata channel first to make sure the |
| 1191 | * number of channels waiting for a rotation cannot |
| 1192 | * reach 0 before we complete the iteration over all |
| 1193 | * the channels. |
| 1194 | */ |
| 1195 | ret = rotate_add_channel_pending(ksess->metadata->key, |
| 1196 | LTTNG_DOMAIN_KERNEL, session); |
| 1197 | if (ret < 0) { |
| 1198 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1199 | goto error; |
| 1200 | } |
| 1201 | |
| 1202 | /* For each channel, ask the consumer to rotate it. */ |
| 1203 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1204 | ret = rotate_add_channel_pending(chan->key, |
| 1205 | LTTNG_DOMAIN_KERNEL, session); |
| 1206 | if (ret < 0) { |
| 1207 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1208 | goto error; |
| 1209 | } |
| 1210 | |
| 1211 | DBG("Rotate channel %" PRIu64 ", session %s", chan->key, session->name); |
| 1212 | ret = consumer_rotate_channel(socket, chan->key, |
| 1213 | ksess->uid, ksess->gid, ksess->consumer, |
| 1214 | ksess->consumer->subdir, |
| 1215 | /* is_metadata_channel */ false, |
| 1216 | session->current_archive_id, |
| 1217 | &session->rotate_pending_relay); |
| 1218 | if (ret < 0) { |
| 1219 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1220 | goto error; |
| 1221 | } |
| 1222 | } |
| 1223 | |
| 1224 | /* |
| 1225 | * Rotate the metadata channel. |
| 1226 | */ |
| 1227 | ret = consumer_rotate_channel(socket, ksess->metadata->key, |
| 1228 | ksess->uid, ksess->gid, ksess->consumer, |
| 1229 | ksess->consumer->subdir, |
| 1230 | /* is_metadata_channel */ true, |
| 1231 | session->current_archive_id, |
| 1232 | &session->rotate_pending_relay); |
| 1233 | if (ret < 0) { |
| 1234 | ret = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1235 | goto error; |
| 1236 | } |
| 1237 | } |
| 1238 | |
| 1239 | ret = LTTNG_OK; |
| 1240 | |
| 1241 | error: |
| 1242 | rcu_read_unlock(); |
| 1243 | return ret; |
| 1244 | } |