| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; only version 2 |
| 7 | * of the License. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <errno.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <stdio.h> |
| 24 | #include <string.h> |
| 25 | #include <unistd.h> |
| 26 | |
| 27 | #include <lttng-kernel-ctl.h> |
| 28 | #include <lttngerr.h> |
| 29 | |
| 30 | #include "kernel.h" |
| 31 | |
| 32 | /* |
| 33 | * Add context on a kernel channel. |
| 34 | */ |
| 35 | int kernel_add_channel_context(struct ltt_kernel_channel *chan, |
| 36 | struct lttng_kernel_context *ctx) |
| 37 | { |
| 38 | int ret; |
| 39 | |
| 40 | DBG("Adding context to channel %s", chan->channel->name); |
| 41 | ret = kernctl_add_context(chan->fd, ctx); |
| 42 | if (ret < 0) { |
| 43 | if (errno != EEXIST) { |
| 44 | perror("add context ioctl"); |
| 45 | } else { |
| 46 | /* If EEXIST, we just ignore the error */ |
| 47 | ret = 0; |
| 48 | } |
| 49 | goto error; |
| 50 | } |
| 51 | |
| 52 | chan->ctx = zmalloc(sizeof(struct lttng_kernel_context)); |
| 53 | if (chan->ctx == NULL) { |
| 54 | perror("zmalloc event context"); |
| 55 | goto error; |
| 56 | } |
| 57 | |
| 58 | memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context)); |
| 59 | |
| 60 | return 0; |
| 61 | |
| 62 | error: |
| 63 | return ret; |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * Add context on a kernel event. |
| 68 | */ |
| 69 | int kernel_add_event_context(struct ltt_kernel_event *event, |
| 70 | struct lttng_kernel_context *ctx) |
| 71 | { |
| 72 | int ret; |
| 73 | |
| 74 | DBG("Adding context to event %s", event->event->name); |
| 75 | ret = kernctl_add_context(event->fd, ctx); |
| 76 | if (ret < 0) { |
| 77 | perror("add context ioctl"); |
| 78 | goto error; |
| 79 | } |
| 80 | |
| 81 | event->ctx = zmalloc(sizeof(struct lttng_kernel_context)); |
| 82 | if (event->ctx == NULL) { |
| 83 | perror("zmalloc event context"); |
| 84 | goto error; |
| 85 | } |
| 86 | |
| 87 | memcpy(event->ctx, ctx, sizeof(struct lttng_kernel_context)); |
| 88 | |
| 89 | return 0; |
| 90 | |
| 91 | error: |
| 92 | return ret; |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * Create a new kernel session, register it to the kernel tracer and add it to |
| 97 | * the session daemon session. |
| 98 | */ |
| 99 | int kernel_create_session(struct ltt_session *session, int tracer_fd) |
| 100 | { |
| 101 | int ret; |
| 102 | struct ltt_kernel_session *lks; |
| 103 | |
| 104 | /* Allocate data structure */ |
| 105 | lks = trace_kernel_create_session(session->path); |
| 106 | if (lks == NULL) { |
| 107 | ret = -1; |
| 108 | goto error; |
| 109 | } |
| 110 | |
| 111 | /* Kernel tracer session creation */ |
| 112 | ret = kernctl_create_session(tracer_fd); |
| 113 | if (ret < 0) { |
| 114 | perror("ioctl kernel create session"); |
| 115 | goto error; |
| 116 | } |
| 117 | |
| 118 | lks->fd = ret; |
| 119 | /* Prevent fd duplication after execlp() */ |
| 120 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 121 | if (ret < 0) { |
| 122 | perror("fcntl session fd"); |
| 123 | } |
| 124 | |
| 125 | lks->consumer_fds_sent = 0; |
| 126 | session->kernel_session = lks; |
| 127 | |
| 128 | DBG("Kernel session created (fd: %d)", lks->fd); |
| 129 | |
| 130 | return 0; |
| 131 | |
| 132 | error: |
| 133 | return ret; |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * Create a kernel channel, register it to the kernel tracer and add it to the |
| 138 | * kernel session. |
| 139 | */ |
| 140 | int kernel_create_channel(struct ltt_kernel_session *session, |
| 141 | struct lttng_channel *chan, char *path) |
| 142 | { |
| 143 | int ret; |
| 144 | struct ltt_kernel_channel *lkc; |
| 145 | |
| 146 | /* Allocate kernel channel */ |
| 147 | lkc = trace_kernel_create_channel(chan, path); |
| 148 | if (lkc == NULL) { |
| 149 | goto error; |
| 150 | } |
| 151 | |
| 152 | /* Kernel tracer channel creation */ |
| 153 | ret = kernctl_create_channel(session->fd, &lkc->channel->attr); |
| 154 | if (ret < 0) { |
| 155 | perror("ioctl kernel create channel"); |
| 156 | goto error; |
| 157 | } |
| 158 | |
| 159 | /* Setup the channel fd */ |
| 160 | lkc->fd = ret; |
| 161 | /* Prevent fd duplication after execlp() */ |
| 162 | ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC); |
| 163 | if (ret < 0) { |
| 164 | perror("fcntl session fd"); |
| 165 | } |
| 166 | |
| 167 | /* Add channel to session */ |
| 168 | cds_list_add(&lkc->list, &session->channel_list.head); |
| 169 | session->channel_count++; |
| 170 | |
| 171 | DBG("Kernel channel %s created (fd: %d and path: %s)", |
| 172 | lkc->channel->name, lkc->fd, lkc->pathname); |
| 173 | |
| 174 | return 0; |
| 175 | |
| 176 | error: |
| 177 | return -1; |
| 178 | } |
| 179 | |
| 180 | /* |
| 181 | * Create a kernel event, enable it to the kernel tracer and add it to the |
| 182 | * channel event list of the kernel session. |
| 183 | */ |
| 184 | int kernel_create_event(struct lttng_event *ev, |
| 185 | struct ltt_kernel_channel *channel) |
| 186 | { |
| 187 | int ret; |
| 188 | struct ltt_kernel_event *event; |
| 189 | |
| 190 | event = trace_kernel_create_event(ev); |
| 191 | if (event == NULL) { |
| 192 | ret = -1; |
| 193 | goto error; |
| 194 | } |
| 195 | |
| 196 | ret = kernctl_create_event(channel->fd, event->event); |
| 197 | if (ret < 0) { |
| 198 | if (errno != EEXIST) { |
| 199 | PERROR("create event ioctl"); |
| 200 | } |
| 201 | ret = -errno; |
| 202 | goto free_event; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * LTTNG_KERNEL_SYSCALL event creation will return 0 on success. However |
| 207 | * this FD must not be added to the event list. |
| 208 | */ |
| 209 | if (ret == 0 && event->event->instrumentation == LTTNG_KERNEL_SYSCALL) { |
| 210 | DBG2("Kernel event syscall creation success"); |
| 211 | goto end; |
| 212 | } |
| 213 | |
| 214 | event->fd = ret; |
| 215 | /* Prevent fd duplication after execlp() */ |
| 216 | ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC); |
| 217 | if (ret < 0) { |
| 218 | perror("fcntl session fd"); |
| 219 | } |
| 220 | |
| 221 | /* Add event to event list */ |
| 222 | cds_list_add(&event->list, &channel->events_list.head); |
| 223 | channel->event_count++; |
| 224 | |
| 225 | DBG("Event %s created (fd: %d)", ev->name, event->fd); |
| 226 | |
| 227 | end: |
| 228 | return 0; |
| 229 | |
| 230 | free_event: |
| 231 | free(event); |
| 232 | error: |
| 233 | return ret; |
| 234 | } |
| 235 | |
| 236 | /* |
| 237 | * Disable a kernel channel. |
| 238 | */ |
| 239 | int kernel_disable_channel(struct ltt_kernel_channel *chan) |
| 240 | { |
| 241 | int ret; |
| 242 | |
| 243 | ret = kernctl_disable(chan->fd); |
| 244 | if (ret < 0) { |
| 245 | perror("disable chan ioctl"); |
| 246 | ret = errno; |
| 247 | goto error; |
| 248 | } |
| 249 | |
| 250 | chan->enabled = 0; |
| 251 | DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd); |
| 252 | |
| 253 | return 0; |
| 254 | |
| 255 | error: |
| 256 | return ret; |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * Enable a kernel channel. |
| 261 | */ |
| 262 | int kernel_enable_channel(struct ltt_kernel_channel *chan) |
| 263 | { |
| 264 | int ret; |
| 265 | |
| 266 | ret = kernctl_enable(chan->fd); |
| 267 | if (ret < 0 && errno != EEXIST) { |
| 268 | perror("Enable kernel chan"); |
| 269 | goto error; |
| 270 | } |
| 271 | |
| 272 | chan->enabled = 1; |
| 273 | DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd); |
| 274 | |
| 275 | return 0; |
| 276 | |
| 277 | error: |
| 278 | return ret; |
| 279 | } |
| 280 | |
| 281 | /* |
| 282 | * Enable a kernel event. |
| 283 | */ |
| 284 | int kernel_enable_event(struct ltt_kernel_event *event) |
| 285 | { |
| 286 | int ret; |
| 287 | |
| 288 | ret = kernctl_enable(event->fd); |
| 289 | if (ret < 0 && errno != EEXIST) { |
| 290 | perror("enable kernel event"); |
| 291 | goto error; |
| 292 | } |
| 293 | |
| 294 | event->enabled = 1; |
| 295 | DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd); |
| 296 | |
| 297 | return 0; |
| 298 | |
| 299 | error: |
| 300 | return ret; |
| 301 | } |
| 302 | |
| 303 | /* |
| 304 | * Disable a kernel event. |
| 305 | */ |
| 306 | int kernel_disable_event(struct ltt_kernel_event *event) |
| 307 | { |
| 308 | int ret; |
| 309 | |
| 310 | ret = kernctl_disable(event->fd); |
| 311 | if (ret < 0 && errno != EEXIST) { |
| 312 | perror("disable kernel event"); |
| 313 | goto error; |
| 314 | } |
| 315 | |
| 316 | event->enabled = 0; |
| 317 | DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd); |
| 318 | |
| 319 | return 0; |
| 320 | |
| 321 | error: |
| 322 | return ret; |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Create kernel metadata, open from the kernel tracer and add it to the |
| 327 | * kernel session. |
| 328 | */ |
| 329 | int kernel_open_metadata(struct ltt_kernel_session *session, char *path) |
| 330 | { |
| 331 | int ret; |
| 332 | struct ltt_kernel_metadata *lkm; |
| 333 | |
| 334 | /* Allocate kernel metadata */ |
| 335 | lkm = trace_kernel_create_metadata(path); |
| 336 | if (lkm == NULL) { |
| 337 | goto error; |
| 338 | } |
| 339 | |
| 340 | /* Kernel tracer metadata creation */ |
| 341 | ret = kernctl_open_metadata(session->fd, &lkm->conf->attr); |
| 342 | if (ret < 0) { |
| 343 | goto error; |
| 344 | } |
| 345 | |
| 346 | lkm->fd = ret; |
| 347 | /* Prevent fd duplication after execlp() */ |
| 348 | ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC); |
| 349 | if (ret < 0) { |
| 350 | perror("fcntl session fd"); |
| 351 | } |
| 352 | |
| 353 | session->metadata = lkm; |
| 354 | |
| 355 | DBG("Kernel metadata opened (fd: %d and path: %s)", lkm->fd, lkm->pathname); |
| 356 | |
| 357 | return 0; |
| 358 | |
| 359 | error: |
| 360 | return -1; |
| 361 | } |
| 362 | |
| 363 | /* |
| 364 | * Start tracing session. |
| 365 | */ |
| 366 | int kernel_start_session(struct ltt_kernel_session *session) |
| 367 | { |
| 368 | int ret; |
| 369 | |
| 370 | ret = kernctl_start_session(session->fd); |
| 371 | if (ret < 0) { |
| 372 | perror("ioctl start session"); |
| 373 | goto error; |
| 374 | } |
| 375 | |
| 376 | DBG("Kernel session started"); |
| 377 | |
| 378 | return 0; |
| 379 | |
| 380 | error: |
| 381 | return ret; |
| 382 | } |
| 383 | |
| 384 | /* |
| 385 | * Make a kernel wait to make sure in-flight probe have completed. |
| 386 | */ |
| 387 | void kernel_wait_quiescent(int fd) |
| 388 | { |
| 389 | int ret; |
| 390 | |
| 391 | DBG("Kernel quiescent wait on %d", fd); |
| 392 | |
| 393 | ret = kernctl_wait_quiescent(fd); |
| 394 | if (ret < 0) { |
| 395 | perror("wait quiescent ioctl"); |
| 396 | ERR("Kernel quiescent wait failed"); |
| 397 | } |
| 398 | } |
| 399 | |
| 400 | /* |
| 401 | * Kernel calibrate |
| 402 | */ |
| 403 | int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate) |
| 404 | { |
| 405 | int ret; |
| 406 | |
| 407 | ret = kernctl_calibrate(fd, calibrate); |
| 408 | if (ret < 0) { |
| 409 | perror("calibrate ioctl"); |
| 410 | return -1; |
| 411 | } |
| 412 | |
| 413 | return 0; |
| 414 | } |
| 415 | |
| 416 | |
| 417 | /* |
| 418 | * Force flush buffer of metadata. |
| 419 | */ |
| 420 | int kernel_metadata_flush_buffer(int fd) |
| 421 | { |
| 422 | int ret; |
| 423 | |
| 424 | ret = kernctl_buffer_flush(fd); |
| 425 | if (ret < 0) { |
| 426 | ERR("Fail to flush metadata buffers %d (ret: %d", fd, ret); |
| 427 | } |
| 428 | |
| 429 | return 0; |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Force flush buffer for channel. |
| 434 | */ |
| 435 | int kernel_flush_buffer(struct ltt_kernel_channel *channel) |
| 436 | { |
| 437 | int ret; |
| 438 | struct ltt_kernel_stream *stream; |
| 439 | |
| 440 | DBG("Flush buffer for channel %s", channel->channel->name); |
| 441 | |
| 442 | cds_list_for_each_entry(stream, &channel->stream_list.head, list) { |
| 443 | DBG("Flushing channel stream %d", stream->fd); |
| 444 | ret = kernctl_buffer_flush(stream->fd); |
| 445 | if (ret < 0) { |
| 446 | perror("ioctl"); |
| 447 | ERR("Fail to flush buffer for stream %d (ret: %d)", |
| 448 | stream->fd, ret); |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | return 0; |
| 453 | } |
| 454 | |
| 455 | /* |
| 456 | * Stop tracing session. |
| 457 | */ |
| 458 | int kernel_stop_session(struct ltt_kernel_session *session) |
| 459 | { |
| 460 | int ret; |
| 461 | |
| 462 | ret = kernctl_stop_session(session->fd); |
| 463 | if (ret < 0) { |
| 464 | goto error; |
| 465 | } |
| 466 | |
| 467 | DBG("Kernel session stopped"); |
| 468 | |
| 469 | return 0; |
| 470 | |
| 471 | error: |
| 472 | return ret; |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * Open stream of channel, register it to the kernel tracer and add it |
| 477 | * to the stream list of the channel. |
| 478 | * |
| 479 | * Return the number of created stream. Else, a negative value. |
| 480 | */ |
| 481 | int kernel_open_channel_stream(struct ltt_kernel_channel *channel) |
| 482 | { |
| 483 | int ret; |
| 484 | struct ltt_kernel_stream *lks; |
| 485 | |
| 486 | while ((ret = kernctl_create_stream(channel->fd)) > 0) { |
| 487 | lks = trace_kernel_create_stream(); |
| 488 | if (lks == NULL) { |
| 489 | close(ret); |
| 490 | goto error; |
| 491 | } |
| 492 | |
| 493 | lks->fd = ret; |
| 494 | /* Prevent fd duplication after execlp() */ |
| 495 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 496 | if (ret < 0) { |
| 497 | perror("fcntl session fd"); |
| 498 | } |
| 499 | |
| 500 | ret = asprintf(&lks->pathname, "%s/%s_%d", |
| 501 | channel->pathname, channel->channel->name, channel->stream_count); |
| 502 | if (ret < 0) { |
| 503 | perror("asprintf kernel create stream"); |
| 504 | goto error; |
| 505 | } |
| 506 | |
| 507 | /* Add stream to channe stream list */ |
| 508 | cds_list_add(&lks->list, &channel->stream_list.head); |
| 509 | channel->stream_count++; |
| 510 | |
| 511 | DBG("Kernel stream %d created (fd: %d, state: %d, path: %s)", |
| 512 | channel->stream_count, lks->fd, lks->state, lks->pathname); |
| 513 | } |
| 514 | |
| 515 | return channel->stream_count; |
| 516 | |
| 517 | error: |
| 518 | return -1; |
| 519 | } |
| 520 | |
| 521 | /* |
| 522 | * Open the metadata stream and set it to the kernel session. |
| 523 | */ |
| 524 | int kernel_open_metadata_stream(struct ltt_kernel_session *session) |
| 525 | { |
| 526 | int ret; |
| 527 | |
| 528 | ret = kernctl_create_stream(session->metadata->fd); |
| 529 | if (ret < 0) { |
| 530 | perror("kernel create metadata stream"); |
| 531 | goto error; |
| 532 | } |
| 533 | |
| 534 | DBG("Kernel metadata stream created (fd: %d)", ret); |
| 535 | session->metadata_stream_fd = ret; |
| 536 | /* Prevent fd duplication after execlp() */ |
| 537 | ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC); |
| 538 | if (ret < 0) { |
| 539 | perror("fcntl session fd"); |
| 540 | } |
| 541 | |
| 542 | return 0; |
| 543 | |
| 544 | error: |
| 545 | return -1; |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * Get the event list from the kernel tracer and return the number of elements. |
| 550 | */ |
| 551 | ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events) |
| 552 | { |
| 553 | int fd, pos; |
| 554 | char *event; |
| 555 | size_t nbmem, count = 0; |
| 556 | ssize_t size; |
| 557 | FILE *fp; |
| 558 | struct lttng_event *elist; |
| 559 | |
| 560 | fd = kernctl_tracepoint_list(tracer_fd); |
| 561 | if (fd < 0) { |
| 562 | perror("kernel tracepoint list"); |
| 563 | goto error; |
| 564 | } |
| 565 | |
| 566 | fp = fdopen(fd, "r"); |
| 567 | if (fp == NULL) { |
| 568 | perror("kernel tracepoint list fdopen"); |
| 569 | goto error_fp; |
| 570 | } |
| 571 | |
| 572 | /* |
| 573 | * Init memory size counter |
| 574 | * See kernel-ctl.h for explanation of this value |
| 575 | */ |
| 576 | nbmem = KERNEL_EVENT_LIST_SIZE; |
| 577 | elist = zmalloc(sizeof(struct lttng_event) * nbmem); |
| 578 | |
| 579 | while ((size = fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) { |
| 580 | if (count > nbmem) { |
| 581 | DBG("Reallocating event list from %zu to %zu bytes", nbmem, |
| 582 | nbmem + KERNEL_EVENT_LIST_SIZE); |
| 583 | /* Adding the default size again */ |
| 584 | nbmem += KERNEL_EVENT_LIST_SIZE; |
| 585 | elist = realloc(elist, nbmem); |
| 586 | if (elist == NULL) { |
| 587 | perror("realloc list events"); |
| 588 | count = -ENOMEM; |
| 589 | goto end; |
| 590 | } |
| 591 | } |
| 592 | strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN); |
| 593 | elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 594 | count++; |
| 595 | } |
| 596 | |
| 597 | *events = elist; |
| 598 | DBG("Kernel list events done (%zu events)", count); |
| 599 | end: |
| 600 | fclose(fp); /* closes both fp and fd */ |
| 601 | return count; |
| 602 | |
| 603 | error_fp: |
| 604 | close(fd); |
| 605 | error: |
| 606 | return -1; |
| 607 | } |