| 1 | /* |
| 2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | #include <fcntl.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <stdio.h> |
| 12 | #include <string.h> |
| 13 | #include <unistd.h> |
| 14 | #include <inttypes.h> |
| 15 | #include <sys/types.h> |
| 16 | |
| 17 | #include <common/common.h> |
| 18 | #include <common/hashtable/utils.h> |
| 19 | #include <common/trace-chunk.h> |
| 20 | #include <common/kernel-ctl/kernel-ctl.h> |
| 21 | #include <common/kernel-ctl/kernel-ioctl.h> |
| 22 | #include <common/sessiond-comm/sessiond-comm.h> |
| 23 | |
| 24 | #include <lttng/userspace-probe.h> |
| 25 | #include <lttng/userspace-probe-internal.h> |
| 26 | #include <lttng/condition/event-rule.h> |
| 27 | #include <lttng/condition/event-rule-internal.h> |
| 28 | #include <lttng/event-rule/event-rule.h> |
| 29 | #include <lttng/event-rule/event-rule-internal.h> |
| 30 | #include <lttng/event-rule/uprobe-internal.h> |
| 31 | |
| 32 | #include "lttng-sessiond.h" |
| 33 | #include "lttng-syscall.h" |
| 34 | #include "consumer.h" |
| 35 | #include "kernel.h" |
| 36 | #include "kernel-consumer.h" |
| 37 | #include "kern-modules.h" |
| 38 | #include "utils.h" |
| 39 | #include "rotate.h" |
| 40 | #include "modprobe.h" |
| 41 | #include "notification-thread-commands.h" |
| 42 | |
| 43 | /* |
| 44 | * Key used to reference a channel between the sessiond and the consumer. This |
| 45 | * is only read and updated with the session_list lock held. |
| 46 | */ |
| 47 | static uint64_t next_kernel_channel_key; |
| 48 | |
| 49 | static const char *module_proc_lttng = "/proc/lttng"; |
| 50 | |
| 51 | static int kernel_tracer_fd = -1; |
| 52 | static int kernel_tracer_trigger_group_fd = -1; |
| 53 | static int kernel_tracer_trigger_group_notification_fd = -1; |
| 54 | static struct ltt_kernel_token_event_rule_list kernel_tracer_token_list; |
| 55 | |
| 56 | /* |
| 57 | * Add context on a kernel channel. |
| 58 | * |
| 59 | * Assumes the ownership of ctx. |
| 60 | */ |
| 61 | int kernel_add_channel_context(struct ltt_kernel_channel *chan, |
| 62 | struct ltt_kernel_context *ctx) |
| 63 | { |
| 64 | int ret; |
| 65 | |
| 66 | assert(chan); |
| 67 | assert(ctx); |
| 68 | |
| 69 | DBG("Adding context to channel %s", chan->channel->name); |
| 70 | ret = kernctl_add_context(chan->fd, &ctx->ctx); |
| 71 | if (ret < 0) { |
| 72 | switch (-ret) { |
| 73 | case ENOSYS: |
| 74 | /* Exists but not available for this kernel */ |
| 75 | ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE; |
| 76 | goto error; |
| 77 | case EEXIST: |
| 78 | /* If EEXIST, we just ignore the error */ |
| 79 | ret = 0; |
| 80 | goto end; |
| 81 | default: |
| 82 | PERROR("add context ioctl"); |
| 83 | ret = LTTNG_ERR_KERN_CONTEXT_FAIL; |
| 84 | goto error; |
| 85 | } |
| 86 | } |
| 87 | ret = 0; |
| 88 | |
| 89 | end: |
| 90 | cds_list_add_tail(&ctx->list, &chan->ctx_list); |
| 91 | ctx->in_list = true; |
| 92 | ctx = NULL; |
| 93 | error: |
| 94 | if (ctx) { |
| 95 | trace_kernel_destroy_context(ctx); |
| 96 | } |
| 97 | return ret; |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * Create a new kernel session, register it to the kernel tracer and add it to |
| 102 | * the session daemon session. |
| 103 | */ |
| 104 | int kernel_create_session(struct ltt_session *session) |
| 105 | { |
| 106 | int ret; |
| 107 | struct ltt_kernel_session *lks; |
| 108 | |
| 109 | assert(session); |
| 110 | |
| 111 | /* Allocate data structure */ |
| 112 | lks = trace_kernel_create_session(); |
| 113 | if (lks == NULL) { |
| 114 | ret = -1; |
| 115 | goto error; |
| 116 | } |
| 117 | |
| 118 | /* Kernel tracer session creation */ |
| 119 | ret = kernctl_create_session(kernel_tracer_fd); |
| 120 | if (ret < 0) { |
| 121 | PERROR("ioctl kernel create session"); |
| 122 | goto error; |
| 123 | } |
| 124 | |
| 125 | lks->fd = ret; |
| 126 | /* Prevent fd duplication after execlp() */ |
| 127 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 128 | if (ret < 0) { |
| 129 | PERROR("fcntl session fd"); |
| 130 | } |
| 131 | |
| 132 | lks->id = session->id; |
| 133 | lks->consumer_fds_sent = 0; |
| 134 | session->kernel_session = lks; |
| 135 | |
| 136 | DBG("Kernel session created (fd: %d)", lks->fd); |
| 137 | |
| 138 | /* |
| 139 | * This is necessary since the creation time is present in the session |
| 140 | * name when it is generated. |
| 141 | */ |
| 142 | if (session->has_auto_generated_name) { |
| 143 | ret = kernctl_session_set_name(lks->fd, DEFAULT_SESSION_NAME); |
| 144 | } else { |
| 145 | ret = kernctl_session_set_name(lks->fd, session->name); |
| 146 | } |
| 147 | if (ret) { |
| 148 | WARN("Could not set kernel session name for session %" PRIu64 " name: %s", |
| 149 | session->id, session->name); |
| 150 | } |
| 151 | |
| 152 | ret = kernctl_session_set_creation_time(lks->fd, session->creation_time); |
| 153 | if (ret) { |
| 154 | WARN("Could not set kernel session creation time for session %" PRIu64 " name: %s", |
| 155 | session->id, session->name); |
| 156 | } |
| 157 | |
| 158 | return 0; |
| 159 | |
| 160 | error: |
| 161 | if (lks) { |
| 162 | trace_kernel_destroy_session(lks); |
| 163 | trace_kernel_free_session(lks); |
| 164 | } |
| 165 | return ret; |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * Create a kernel channel, register it to the kernel tracer and add it to the |
| 170 | * kernel session. |
| 171 | */ |
| 172 | int kernel_create_channel(struct ltt_kernel_session *session, |
| 173 | struct lttng_channel *chan) |
| 174 | { |
| 175 | int ret; |
| 176 | struct ltt_kernel_channel *lkc; |
| 177 | |
| 178 | assert(session); |
| 179 | assert(chan); |
| 180 | |
| 181 | /* Allocate kernel channel */ |
| 182 | lkc = trace_kernel_create_channel(chan); |
| 183 | if (lkc == NULL) { |
| 184 | goto error; |
| 185 | } |
| 186 | |
| 187 | DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d", |
| 188 | chan->name, lkc->channel->attr.overwrite, |
| 189 | lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf, |
| 190 | lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval, |
| 191 | lkc->channel->attr.live_timer_interval, lkc->channel->attr.output); |
| 192 | |
| 193 | /* Kernel tracer channel creation */ |
| 194 | ret = kernctl_create_channel(session->fd, &lkc->channel->attr); |
| 195 | if (ret < 0) { |
| 196 | PERROR("ioctl kernel create channel"); |
| 197 | goto error; |
| 198 | } |
| 199 | |
| 200 | /* Setup the channel fd */ |
| 201 | lkc->fd = ret; |
| 202 | /* Prevent fd duplication after execlp() */ |
| 203 | ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC); |
| 204 | if (ret < 0) { |
| 205 | PERROR("fcntl session fd"); |
| 206 | } |
| 207 | |
| 208 | /* Add channel to session */ |
| 209 | cds_list_add(&lkc->list, &session->channel_list.head); |
| 210 | session->channel_count++; |
| 211 | lkc->session = session; |
| 212 | lkc->key = ++next_kernel_channel_key; |
| 213 | |
| 214 | DBG("Kernel channel %s created (fd: %d, key: %" PRIu64 ")", |
| 215 | lkc->channel->name, lkc->fd, lkc->key); |
| 216 | |
| 217 | return 0; |
| 218 | |
| 219 | error: |
| 220 | if (lkc) { |
| 221 | free(lkc->channel); |
| 222 | free(lkc); |
| 223 | } |
| 224 | return -1; |
| 225 | } |
| 226 | |
| 227 | /* |
| 228 | * Create a kernel channel, register it to the kernel tracer and add it to the |
| 229 | * kernel session. |
| 230 | */ |
| 231 | static |
| 232 | int kernel_create_trigger_group(int *trigger_group_fd) |
| 233 | { |
| 234 | int ret; |
| 235 | int local_fd = -1; |
| 236 | |
| 237 | assert(trigger_group_fd); |
| 238 | |
| 239 | /* Kernel tracer channel creation */ |
| 240 | ret = kernctl_create_trigger_group(kernel_tracer_fd); |
| 241 | if (ret < 0) { |
| 242 | PERROR("ioctl kernel create trigger group"); |
| 243 | ret = -1; |
| 244 | goto error; |
| 245 | } |
| 246 | |
| 247 | /* Store locally */ |
| 248 | local_fd = ret; |
| 249 | |
| 250 | /* Prevent fd duplication after execlp() */ |
| 251 | ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC); |
| 252 | if (ret < 0) { |
| 253 | PERROR("fcntl session fd"); |
| 254 | } |
| 255 | |
| 256 | DBG("Kernel trigger group created (fd: %d)", |
| 257 | local_fd); |
| 258 | ret = 0; |
| 259 | |
| 260 | error: |
| 261 | *trigger_group_fd = local_fd; |
| 262 | return ret; |
| 263 | } |
| 264 | |
| 265 | /* |
| 266 | * Compute the offset of the instrumentation byte in the binary based on the |
| 267 | * function probe location using the ELF lookup method. |
| 268 | * |
| 269 | * Returns 0 on success and set the offset out parameter to the offset of the |
| 270 | * elf symbol |
| 271 | * Returns -1 on error |
| 272 | */ |
| 273 | static |
| 274 | int extract_userspace_probe_offset_function_elf( |
| 275 | const struct lttng_userspace_probe_location *probe_location, |
| 276 | uid_t uid, gid_t gid, uint64_t *offset) |
| 277 | { |
| 278 | int fd; |
| 279 | int ret = 0; |
| 280 | const char *symbol = NULL; |
| 281 | const struct lttng_userspace_probe_location_lookup_method *lookup = NULL; |
| 282 | enum lttng_userspace_probe_location_lookup_method_type lookup_method_type; |
| 283 | |
| 284 | assert(lttng_userspace_probe_location_get_type(probe_location) == |
| 285 | LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION); |
| 286 | |
| 287 | lookup = lttng_userspace_probe_location_get_lookup_method( |
| 288 | probe_location); |
| 289 | if (!lookup) { |
| 290 | ret = -1; |
| 291 | goto end; |
| 292 | } |
| 293 | |
| 294 | lookup_method_type = |
| 295 | lttng_userspace_probe_location_lookup_method_get_type(lookup); |
| 296 | |
| 297 | assert(lookup_method_type == |
| 298 | LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF); |
| 299 | |
| 300 | symbol = lttng_userspace_probe_location_function_get_function_name( |
| 301 | probe_location); |
| 302 | if (!symbol) { |
| 303 | ret = -1; |
| 304 | goto end; |
| 305 | } |
| 306 | |
| 307 | fd = lttng_userspace_probe_location_function_get_binary_fd(probe_location); |
| 308 | if (fd < 0) { |
| 309 | ret = -1; |
| 310 | goto end; |
| 311 | } |
| 312 | |
| 313 | ret = run_as_extract_elf_symbol_offset(fd, symbol, uid, gid, offset); |
| 314 | if (ret < 0) { |
| 315 | DBG("userspace probe offset calculation failed for " |
| 316 | "function %s", symbol); |
| 317 | goto end; |
| 318 | } |
| 319 | |
| 320 | DBG("userspace probe elf offset for %s is 0x%jd", symbol, (intmax_t)(*offset)); |
| 321 | end: |
| 322 | return ret; |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Compute the offsets of the instrumentation bytes in the binary based on the |
| 327 | * tracepoint probe location using the SDT lookup method. This function |
| 328 | * allocates the offsets buffer, the caller must free it. |
| 329 | * |
| 330 | * Returns 0 on success and set the offset out parameter to the offsets of the |
| 331 | * SDT tracepoint. |
| 332 | * Returns -1 on error. |
| 333 | */ |
| 334 | static |
| 335 | int extract_userspace_probe_offset_tracepoint_sdt( |
| 336 | const struct lttng_userspace_probe_location *probe_location, |
| 337 | uid_t uid, gid_t gid, uint64_t **offsets, |
| 338 | uint32_t *offsets_count) |
| 339 | { |
| 340 | enum lttng_userspace_probe_location_lookup_method_type lookup_method_type; |
| 341 | const struct lttng_userspace_probe_location_lookup_method *lookup = NULL; |
| 342 | const char *probe_name = NULL, *provider_name = NULL; |
| 343 | int ret = 0; |
| 344 | int fd, i; |
| 345 | |
| 346 | assert(lttng_userspace_probe_location_get_type(probe_location) == |
| 347 | LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT); |
| 348 | |
| 349 | lookup = lttng_userspace_probe_location_get_lookup_method(probe_location); |
| 350 | if (!lookup) { |
| 351 | ret = -1; |
| 352 | goto end; |
| 353 | } |
| 354 | |
| 355 | lookup_method_type = |
| 356 | lttng_userspace_probe_location_lookup_method_get_type(lookup); |
| 357 | |
| 358 | assert(lookup_method_type == |
| 359 | LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT); |
| 360 | |
| 361 | |
| 362 | probe_name = lttng_userspace_probe_location_tracepoint_get_probe_name( |
| 363 | probe_location); |
| 364 | if (!probe_name) { |
| 365 | ret = -1; |
| 366 | goto end; |
| 367 | } |
| 368 | |
| 369 | provider_name = lttng_userspace_probe_location_tracepoint_get_provider_name( |
| 370 | probe_location); |
| 371 | if (!provider_name) { |
| 372 | ret = -1; |
| 373 | goto end; |
| 374 | } |
| 375 | |
| 376 | fd = lttng_userspace_probe_location_tracepoint_get_binary_fd(probe_location); |
| 377 | if (fd < 0) { |
| 378 | ret = -1; |
| 379 | goto end; |
| 380 | } |
| 381 | |
| 382 | ret = run_as_extract_sdt_probe_offsets(fd, provider_name, probe_name, |
| 383 | uid, gid, offsets, offsets_count); |
| 384 | if (ret < 0) { |
| 385 | DBG("userspace probe offset calculation failed for sdt " |
| 386 | "probe %s:%s", provider_name, probe_name); |
| 387 | goto end; |
| 388 | } |
| 389 | |
| 390 | if (*offsets_count == 0) { |
| 391 | DBG("no userspace probe offset found"); |
| 392 | goto end; |
| 393 | } |
| 394 | |
| 395 | DBG("%u userspace probe SDT offsets found for %s:%s at:", |
| 396 | *offsets_count, provider_name, probe_name); |
| 397 | for (i = 0; i < *offsets_count; i++) { |
| 398 | DBG("\t0x%jd", (intmax_t)((*offsets)[i])); |
| 399 | } |
| 400 | end: |
| 401 | return ret; |
| 402 | } |
| 403 | |
| 404 | static |
| 405 | int userspace_probe_add_callsite( |
| 406 | const struct lttng_userspace_probe_location *location, |
| 407 | uid_t uid, gid_t gid, int fd) |
| 408 | { |
| 409 | const struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL; |
| 410 | enum lttng_userspace_probe_location_lookup_method_type type; |
| 411 | int ret; |
| 412 | |
| 413 | lookup_method = lttng_userspace_probe_location_get_lookup_method(location); |
| 414 | if (!lookup_method) { |
| 415 | ret = -1; |
| 416 | goto end; |
| 417 | } |
| 418 | |
| 419 | type = lttng_userspace_probe_location_lookup_method_get_type(lookup_method); |
| 420 | switch (type) { |
| 421 | case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF: |
| 422 | { |
| 423 | struct lttng_kernel_event_callsite callsite; |
| 424 | uint64_t offset; |
| 425 | |
| 426 | ret = extract_userspace_probe_offset_function_elf(location, |
| 427 | uid, gid, &offset); |
| 428 | if (ret) { |
| 429 | ret = LTTNG_ERR_PROBE_LOCATION_INVAL; |
| 430 | goto end; |
| 431 | } |
| 432 | |
| 433 | callsite.u.uprobe.offset = offset; |
| 434 | ret = kernctl_add_callsite(fd, &callsite); |
| 435 | if (ret) { |
| 436 | WARN("Adding callsite to ELF userspace probe failed."); |
| 437 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 438 | goto end; |
| 439 | } |
| 440 | break; |
| 441 | } |
| 442 | case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT: |
| 443 | { |
| 444 | int i; |
| 445 | uint64_t *offsets = NULL; |
| 446 | uint32_t offsets_count; |
| 447 | struct lttng_kernel_event_callsite callsite; |
| 448 | |
| 449 | /* |
| 450 | * This call allocates the offsets buffer. This buffer must be freed |
| 451 | * by the caller |
| 452 | */ |
| 453 | ret = extract_userspace_probe_offset_tracepoint_sdt(location, |
| 454 | uid, gid, &offsets, &offsets_count); |
| 455 | if (ret) { |
| 456 | ret = LTTNG_ERR_PROBE_LOCATION_INVAL; |
| 457 | goto end; |
| 458 | } |
| 459 | for (i = 0; i < offsets_count; i++) { |
| 460 | callsite.u.uprobe.offset = offsets[i]; |
| 461 | ret = kernctl_add_callsite(fd, &callsite); |
| 462 | if (ret) { |
| 463 | WARN("Adding callsite to SDT userspace probe " |
| 464 | "failed."); |
| 465 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 466 | free(offsets); |
| 467 | goto end; |
| 468 | } |
| 469 | } |
| 470 | free(offsets); |
| 471 | break; |
| 472 | } |
| 473 | default: |
| 474 | ret = LTTNG_ERR_PROBE_LOCATION_INVAL; |
| 475 | goto end; |
| 476 | } |
| 477 | end: |
| 478 | return ret; |
| 479 | } |
| 480 | |
| 481 | /* |
| 482 | * Extract the offsets of the instrumentation point for the different lookup |
| 483 | * methods. |
| 484 | */ |
| 485 | static |
| 486 | int userspace_probe_event_add_callsites(struct lttng_event *ev, |
| 487 | struct ltt_kernel_session *session, int fd) |
| 488 | { |
| 489 | const struct lttng_userspace_probe_location *location = NULL; |
| 490 | int ret; |
| 491 | |
| 492 | assert(ev); |
| 493 | assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE); |
| 494 | |
| 495 | location = lttng_event_get_userspace_probe_location(ev); |
| 496 | if (!location) { |
| 497 | ret = -1; |
| 498 | goto end; |
| 499 | } |
| 500 | |
| 501 | ret = userspace_probe_add_callsite(location, session->uid, session->gid, |
| 502 | fd); |
| 503 | if (ret) { |
| 504 | WARN("Adding callsite to userspace probe event \"%s\" " |
| 505 | "failed.", ev->name); |
| 506 | } |
| 507 | |
| 508 | end: |
| 509 | return ret; |
| 510 | } |
| 511 | |
| 512 | /* |
| 513 | * Extract the offsets of the instrumentation point for the different lookup |
| 514 | * methods. |
| 515 | */ |
| 516 | static int userspace_probe_event_rule_add_callsites( |
| 517 | const struct lttng_event_rule *rule, |
| 518 | const struct lttng_credentials *creds, |
| 519 | int fd) |
| 520 | { |
| 521 | const struct lttng_userspace_probe_location *location = NULL; |
| 522 | enum lttng_event_rule_status status; |
| 523 | int ret; |
| 524 | |
| 525 | assert(rule); |
| 526 | assert(creds); |
| 527 | assert(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_UPROBE); |
| 528 | |
| 529 | status = lttng_event_rule_uprobe_get_location(rule, &location); |
| 530 | if (status != LTTNG_EVENT_RULE_STATUS_OK || !location) { |
| 531 | ret = -1; |
| 532 | goto end; |
| 533 | } |
| 534 | |
| 535 | ret = userspace_probe_add_callsite(location, creds->uid, creds->gid, |
| 536 | fd); |
| 537 | if (ret) { |
| 538 | WARN("Adding callsite to userspace probe object %d" |
| 539 | "failed.", fd); |
| 540 | } |
| 541 | |
| 542 | end: |
| 543 | return ret; |
| 544 | } |
| 545 | |
| 546 | /* |
| 547 | * Create a kernel event, enable it to the kernel tracer and add it to the |
| 548 | * channel event list of the kernel session. |
| 549 | * We own filter_expression and filter. |
| 550 | */ |
| 551 | int kernel_create_event(struct lttng_event *ev, |
| 552 | struct ltt_kernel_channel *channel, |
| 553 | char *filter_expression, |
| 554 | struct lttng_filter_bytecode *filter) |
| 555 | { |
| 556 | int err, fd; |
| 557 | enum lttng_error_code ret; |
| 558 | struct ltt_kernel_event *event; |
| 559 | |
| 560 | assert(ev); |
| 561 | assert(channel); |
| 562 | |
| 563 | /* We pass ownership of filter_expression and filter */ |
| 564 | ret = trace_kernel_create_event(ev, filter_expression, |
| 565 | filter, &event); |
| 566 | if (ret != LTTNG_OK) { |
| 567 | goto error; |
| 568 | } |
| 569 | |
| 570 | fd = kernctl_create_event(channel->fd, event->event); |
| 571 | if (fd < 0) { |
| 572 | switch (-fd) { |
| 573 | case EEXIST: |
| 574 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 575 | break; |
| 576 | case ENOSYS: |
| 577 | WARN("Event type not implemented"); |
| 578 | ret = LTTNG_ERR_KERN_EVENT_ENOSYS; |
| 579 | break; |
| 580 | case ENOENT: |
| 581 | WARN("Event %s not found!", ev->name); |
| 582 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 583 | break; |
| 584 | default: |
| 585 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 586 | PERROR("create event ioctl"); |
| 587 | } |
| 588 | goto free_event; |
| 589 | } |
| 590 | |
| 591 | event->type = ev->type; |
| 592 | event->fd = fd; |
| 593 | /* Prevent fd duplication after execlp() */ |
| 594 | err = fcntl(event->fd, F_SETFD, FD_CLOEXEC); |
| 595 | if (err < 0) { |
| 596 | PERROR("fcntl session fd"); |
| 597 | } |
| 598 | |
| 599 | if (filter) { |
| 600 | err = kernctl_filter(event->fd, filter); |
| 601 | if (err < 0) { |
| 602 | switch (-err) { |
| 603 | case ENOMEM: |
| 604 | ret = LTTNG_ERR_FILTER_NOMEM; |
| 605 | break; |
| 606 | default: |
| 607 | ret = LTTNG_ERR_FILTER_INVAL; |
| 608 | break; |
| 609 | } |
| 610 | goto filter_error; |
| 611 | } |
| 612 | } |
| 613 | |
| 614 | if (ev->type == LTTNG_EVENT_USERSPACE_PROBE) { |
| 615 | ret = userspace_probe_event_add_callsites(ev, channel->session, |
| 616 | event->fd); |
| 617 | if (ret) { |
| 618 | goto add_callsite_error; |
| 619 | } |
| 620 | } |
| 621 | |
| 622 | err = kernctl_enable(event->fd); |
| 623 | if (err < 0) { |
| 624 | switch (-err) { |
| 625 | case EEXIST: |
| 626 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 627 | break; |
| 628 | default: |
| 629 | PERROR("enable kernel event"); |
| 630 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 631 | break; |
| 632 | } |
| 633 | goto enable_error; |
| 634 | } |
| 635 | |
| 636 | /* Add event to event list */ |
| 637 | cds_list_add(&event->list, &channel->events_list.head); |
| 638 | channel->event_count++; |
| 639 | |
| 640 | DBG("Event %s created (fd: %d)", ev->name, event->fd); |
| 641 | |
| 642 | return 0; |
| 643 | |
| 644 | add_callsite_error: |
| 645 | enable_error: |
| 646 | filter_error: |
| 647 | { |
| 648 | int closeret; |
| 649 | |
| 650 | closeret = close(event->fd); |
| 651 | if (closeret) { |
| 652 | PERROR("close event fd"); |
| 653 | } |
| 654 | } |
| 655 | free_event: |
| 656 | free(event); |
| 657 | error: |
| 658 | return ret; |
| 659 | } |
| 660 | |
| 661 | /* |
| 662 | * Disable a kernel channel. |
| 663 | */ |
| 664 | int kernel_disable_channel(struct ltt_kernel_channel *chan) |
| 665 | { |
| 666 | int ret; |
| 667 | |
| 668 | assert(chan); |
| 669 | |
| 670 | ret = kernctl_disable(chan->fd); |
| 671 | if (ret < 0) { |
| 672 | PERROR("disable chan ioctl"); |
| 673 | goto error; |
| 674 | } |
| 675 | |
| 676 | chan->enabled = 0; |
| 677 | DBG("Kernel channel %s disabled (fd: %d, key: %" PRIu64 ")", |
| 678 | chan->channel->name, chan->fd, chan->key); |
| 679 | |
| 680 | return 0; |
| 681 | |
| 682 | error: |
| 683 | return ret; |
| 684 | } |
| 685 | |
| 686 | /* |
| 687 | * Enable a kernel channel. |
| 688 | */ |
| 689 | int kernel_enable_channel(struct ltt_kernel_channel *chan) |
| 690 | { |
| 691 | int ret; |
| 692 | |
| 693 | assert(chan); |
| 694 | |
| 695 | ret = kernctl_enable(chan->fd); |
| 696 | if (ret < 0 && ret != -EEXIST) { |
| 697 | PERROR("Enable kernel chan"); |
| 698 | goto error; |
| 699 | } |
| 700 | |
| 701 | chan->enabled = 1; |
| 702 | DBG("Kernel channel %s enabled (fd: %d, key: %" PRIu64 ")", |
| 703 | chan->channel->name, chan->fd, chan->key); |
| 704 | |
| 705 | return 0; |
| 706 | |
| 707 | error: |
| 708 | return ret; |
| 709 | } |
| 710 | |
| 711 | /* |
| 712 | * Enable a kernel event. |
| 713 | */ |
| 714 | int kernel_enable_event(struct ltt_kernel_event *event) |
| 715 | { |
| 716 | int ret; |
| 717 | |
| 718 | assert(event); |
| 719 | |
| 720 | ret = kernctl_enable(event->fd); |
| 721 | if (ret < 0) { |
| 722 | switch (-ret) { |
| 723 | case EEXIST: |
| 724 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 725 | break; |
| 726 | default: |
| 727 | PERROR("enable kernel event"); |
| 728 | break; |
| 729 | } |
| 730 | goto error; |
| 731 | } |
| 732 | |
| 733 | event->enabled = 1; |
| 734 | DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd); |
| 735 | |
| 736 | return 0; |
| 737 | |
| 738 | error: |
| 739 | return ret; |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Disable a kernel event. |
| 744 | */ |
| 745 | int kernel_disable_event(struct ltt_kernel_event *event) |
| 746 | { |
| 747 | int ret; |
| 748 | |
| 749 | assert(event); |
| 750 | |
| 751 | ret = kernctl_disable(event->fd); |
| 752 | if (ret < 0) { |
| 753 | switch (-ret) { |
| 754 | case EEXIST: |
| 755 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 756 | break; |
| 757 | default: |
| 758 | PERROR("disable kernel event"); |
| 759 | break; |
| 760 | } |
| 761 | goto error; |
| 762 | } |
| 763 | |
| 764 | event->enabled = 0; |
| 765 | DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd); |
| 766 | |
| 767 | return 0; |
| 768 | |
| 769 | error: |
| 770 | return ret; |
| 771 | } |
| 772 | |
| 773 | /* |
| 774 | * Disable a kernel trigger. |
| 775 | */ |
| 776 | int kernel_disable_token_event_rule(struct ltt_kernel_token_event_rule *event) |
| 777 | { |
| 778 | int ret; |
| 779 | |
| 780 | assert(event); |
| 781 | |
| 782 | ret = kernctl_disable(event->fd); |
| 783 | if (ret < 0) { |
| 784 | switch (-ret) { |
| 785 | case EEXIST: |
| 786 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 787 | break; |
| 788 | default: |
| 789 | PERROR("disable kernel event"); |
| 790 | break; |
| 791 | } |
| 792 | goto error; |
| 793 | } |
| 794 | |
| 795 | event->enabled = 0; |
| 796 | DBG("Kernel trigger token %" PRIu64" disabled (fd: %d)", event->token, event->fd); |
| 797 | |
| 798 | return 0; |
| 799 | |
| 800 | error: |
| 801 | return ret; |
| 802 | } |
| 803 | static struct lttng_tracker_list *get_id_tracker_list( |
| 804 | struct ltt_kernel_session *session, |
| 805 | enum lttng_tracker_type tracker_type) |
| 806 | { |
| 807 | switch (tracker_type) { |
| 808 | case LTTNG_TRACKER_PID: |
| 809 | return session->tracker_list_pid; |
| 810 | case LTTNG_TRACKER_VPID: |
| 811 | return session->tracker_list_vpid; |
| 812 | case LTTNG_TRACKER_UID: |
| 813 | return session->tracker_list_uid; |
| 814 | case LTTNG_TRACKER_VUID: |
| 815 | return session->tracker_list_vuid; |
| 816 | case LTTNG_TRACKER_GID: |
| 817 | return session->tracker_list_gid; |
| 818 | case LTTNG_TRACKER_VGID: |
| 819 | return session->tracker_list_vgid; |
| 820 | default: |
| 821 | return NULL; |
| 822 | } |
| 823 | } |
| 824 | |
| 825 | int kernel_track_id(enum lttng_tracker_type tracker_type, |
| 826 | struct ltt_kernel_session *session, |
| 827 | const struct lttng_tracker_id *id) |
| 828 | { |
| 829 | int ret, value; |
| 830 | struct lttng_tracker_list *tracker_list; |
| 831 | struct lttng_tracker_ids *saved_ids; |
| 832 | |
| 833 | ret = lttng_tracker_id_lookup_string(tracker_type, id, &value); |
| 834 | if (ret != LTTNG_OK) { |
| 835 | return ret; |
| 836 | } |
| 837 | |
| 838 | tracker_list = get_id_tracker_list(session, tracker_type); |
| 839 | if (!tracker_list) { |
| 840 | return LTTNG_ERR_INVALID; |
| 841 | } |
| 842 | |
| 843 | /* Save list for restore on error. */ |
| 844 | ret = lttng_tracker_id_get_list(tracker_list, &saved_ids); |
| 845 | if (ret != LTTNG_OK) { |
| 846 | return LTTNG_ERR_INVALID; |
| 847 | } |
| 848 | |
| 849 | /* Add to list. */ |
| 850 | ret = lttng_tracker_list_add(tracker_list, id); |
| 851 | if (ret != LTTNG_OK) { |
| 852 | goto end; |
| 853 | } |
| 854 | |
| 855 | switch (tracker_type) { |
| 856 | case LTTNG_TRACKER_PID: |
| 857 | DBG("Kernel track PID %d for session id %" PRIu64 ".", value, |
| 858 | session->id); |
| 859 | ret = kernctl_track_pid(session->fd, value); |
| 860 | if (!ret) { |
| 861 | ret = LTTNG_OK; |
| 862 | goto end; |
| 863 | } |
| 864 | break; |
| 865 | case LTTNG_TRACKER_VPID: |
| 866 | DBG("Kernel track VPID %d for session id %" PRIu64 ".", value, |
| 867 | session->id); |
| 868 | ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VPID, value); |
| 869 | if (!ret) { |
| 870 | ret = LTTNG_OK; |
| 871 | goto end; |
| 872 | } |
| 873 | break; |
| 874 | case LTTNG_TRACKER_UID: |
| 875 | DBG("Kernel track UID %d for session id %" PRIu64 ".", value, |
| 876 | session->id); |
| 877 | ret = kernctl_track_id(session->fd, LTTNG_TRACKER_UID, value); |
| 878 | if (!ret) { |
| 879 | ret = LTTNG_OK; |
| 880 | goto end; |
| 881 | } |
| 882 | break; |
| 883 | case LTTNG_TRACKER_GID: |
| 884 | DBG("Kernel track GID %d for session id %" PRIu64 ".", value, |
| 885 | session->id); |
| 886 | ret = kernctl_track_id(session->fd, LTTNG_TRACKER_GID, value); |
| 887 | if (!ret) { |
| 888 | ret = LTTNG_OK; |
| 889 | goto end; |
| 890 | } |
| 891 | break; |
| 892 | case LTTNG_TRACKER_VUID: |
| 893 | DBG("Kernel track VUID %d for session id %" PRIu64 ".", value, |
| 894 | session->id); |
| 895 | ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VUID, value); |
| 896 | if (!ret) { |
| 897 | ret = LTTNG_OK; |
| 898 | goto end; |
| 899 | } |
| 900 | break; |
| 901 | case LTTNG_TRACKER_VGID: |
| 902 | DBG("Kernel track VGID %d for session id %" PRIu64 ".", value, |
| 903 | session->id); |
| 904 | ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VGID, value); |
| 905 | if (!ret) { |
| 906 | ret = LTTNG_OK; |
| 907 | goto end; |
| 908 | } |
| 909 | break; |
| 910 | default: |
| 911 | ret = -EINVAL; |
| 912 | break; |
| 913 | } |
| 914 | |
| 915 | /* Error handling. */ |
| 916 | switch (-ret) { |
| 917 | case EINVAL: |
| 918 | ret = LTTNG_ERR_INVALID; |
| 919 | break; |
| 920 | case ENOMEM: |
| 921 | ret = LTTNG_ERR_NOMEM; |
| 922 | break; |
| 923 | case EEXIST: |
| 924 | ret = LTTNG_ERR_ID_TRACKED; |
| 925 | break; |
| 926 | default: |
| 927 | ret = LTTNG_ERR_UNK; |
| 928 | break; |
| 929 | } |
| 930 | |
| 931 | if (lttng_tracker_id_set_list(tracker_list, saved_ids) != LTTNG_OK) { |
| 932 | ERR("Error on tracker add error handling.\n"); |
| 933 | } |
| 934 | end: |
| 935 | lttng_tracker_ids_destroy(saved_ids); |
| 936 | return ret; |
| 937 | } |
| 938 | |
| 939 | int kernel_untrack_id(enum lttng_tracker_type tracker_type, |
| 940 | struct ltt_kernel_session *session, |
| 941 | const struct lttng_tracker_id *id) |
| 942 | { |
| 943 | int ret, value; |
| 944 | struct lttng_tracker_list *tracker_list; |
| 945 | struct lttng_tracker_ids *saved_ids; |
| 946 | |
| 947 | ret = lttng_tracker_id_lookup_string(tracker_type, id, &value); |
| 948 | if (ret != LTTNG_OK) { |
| 949 | return ret; |
| 950 | } |
| 951 | |
| 952 | tracker_list = get_id_tracker_list(session, tracker_type); |
| 953 | if (!tracker_list) { |
| 954 | return LTTNG_ERR_INVALID; |
| 955 | } |
| 956 | /* Save list for restore on error. */ |
| 957 | ret = lttng_tracker_id_get_list(tracker_list, &saved_ids); |
| 958 | if (ret != LTTNG_OK) { |
| 959 | return LTTNG_ERR_INVALID; |
| 960 | } |
| 961 | /* Remove from list. */ |
| 962 | ret = lttng_tracker_list_remove(tracker_list, id); |
| 963 | if (ret != LTTNG_OK) { |
| 964 | goto end; |
| 965 | } |
| 966 | |
| 967 | switch (tracker_type) { |
| 968 | case LTTNG_TRACKER_PID: |
| 969 | DBG("Kernel untrack PID %d for session id %" PRIu64 ".", value, |
| 970 | session->id); |
| 971 | ret = kernctl_untrack_pid(session->fd, value); |
| 972 | if (!ret) { |
| 973 | ret = LTTNG_OK; |
| 974 | goto end; |
| 975 | } |
| 976 | break; |
| 977 | case LTTNG_TRACKER_VPID: |
| 978 | DBG("Kernel untrack VPID %d for session id %" PRIu64 ".", value, |
| 979 | session->id); |
| 980 | ret = kernctl_untrack_id( |
| 981 | session->fd, LTTNG_TRACKER_VPID, value); |
| 982 | if (!ret) { |
| 983 | ret = LTTNG_OK; |
| 984 | goto end; |
| 985 | } |
| 986 | break; |
| 987 | case LTTNG_TRACKER_UID: |
| 988 | DBG("Kernel untrack UID %d for session id %" PRIu64 ".", value, |
| 989 | session->id); |
| 990 | ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_UID, value); |
| 991 | if (!ret) { |
| 992 | ret = LTTNG_OK; |
| 993 | goto end; |
| 994 | } |
| 995 | break; |
| 996 | case LTTNG_TRACKER_GID: |
| 997 | DBG("Kernel untrack GID %d for session id %" PRIu64 ".", value, |
| 998 | session->id); |
| 999 | ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_GID, value); |
| 1000 | if (!ret) { |
| 1001 | ret = LTTNG_OK; |
| 1002 | goto end; |
| 1003 | } |
| 1004 | break; |
| 1005 | case LTTNG_TRACKER_VUID: |
| 1006 | DBG("Kernel untrack VUID %d for session id %" PRIu64 ".", value, |
| 1007 | session->id); |
| 1008 | ret = kernctl_untrack_id( |
| 1009 | session->fd, LTTNG_TRACKER_VUID, value); |
| 1010 | if (!ret) { |
| 1011 | ret = LTTNG_OK; |
| 1012 | goto end; |
| 1013 | } |
| 1014 | break; |
| 1015 | case LTTNG_TRACKER_VGID: |
| 1016 | DBG("Kernel untrack VGID %d for session id %" PRIu64 ".", value, |
| 1017 | session->id); |
| 1018 | ret = kernctl_untrack_id( |
| 1019 | session->fd, LTTNG_TRACKER_VGID, value); |
| 1020 | if (!ret) { |
| 1021 | ret = LTTNG_OK; |
| 1022 | goto end; |
| 1023 | } |
| 1024 | break; |
| 1025 | default: |
| 1026 | ret = -EINVAL; |
| 1027 | break; |
| 1028 | } |
| 1029 | |
| 1030 | /* Error handling. */ |
| 1031 | switch (-ret) { |
| 1032 | case EINVAL: |
| 1033 | ret = LTTNG_ERR_INVALID; |
| 1034 | break; |
| 1035 | case ENOMEM: |
| 1036 | ret = LTTNG_ERR_NOMEM; |
| 1037 | break; |
| 1038 | case EEXIST: |
| 1039 | ret = LTTNG_ERR_ID_TRACKED; |
| 1040 | break; |
| 1041 | default: |
| 1042 | ret = LTTNG_ERR_UNK; |
| 1043 | break; |
| 1044 | } |
| 1045 | |
| 1046 | if (lttng_tracker_id_set_list(tracker_list, saved_ids) != LTTNG_OK) { |
| 1047 | ERR("Error on tracker remove error handling.\n"); |
| 1048 | } |
| 1049 | end: |
| 1050 | lttng_tracker_ids_destroy(saved_ids); |
| 1051 | return ret; |
| 1052 | } |
| 1053 | |
| 1054 | /* |
| 1055 | * Called with session lock held. |
| 1056 | */ |
| 1057 | int kernel_list_tracker_ids(enum lttng_tracker_type tracker_type, |
| 1058 | struct ltt_kernel_session *session, |
| 1059 | struct lttng_tracker_ids **_ids) |
| 1060 | { |
| 1061 | int ret = 0; |
| 1062 | struct lttng_tracker_list *tracker_list; |
| 1063 | |
| 1064 | tracker_list = get_id_tracker_list(session, tracker_type); |
| 1065 | if (!tracker_list) { |
| 1066 | ret = -LTTNG_ERR_INVALID; |
| 1067 | goto end; |
| 1068 | } |
| 1069 | |
| 1070 | ret = lttng_tracker_id_get_list(tracker_list, _ids); |
| 1071 | if (ret != LTTNG_OK) { |
| 1072 | ret = -LTTNG_ERR_INVALID; |
| 1073 | goto end; |
| 1074 | } |
| 1075 | |
| 1076 | end: |
| 1077 | return ret; |
| 1078 | } |
| 1079 | |
| 1080 | /* |
| 1081 | * Create kernel metadata, open from the kernel tracer and add it to the |
| 1082 | * kernel session. |
| 1083 | */ |
| 1084 | int kernel_open_metadata(struct ltt_kernel_session *session) |
| 1085 | { |
| 1086 | int ret; |
| 1087 | struct ltt_kernel_metadata *lkm = NULL; |
| 1088 | |
| 1089 | assert(session); |
| 1090 | |
| 1091 | /* Allocate kernel metadata */ |
| 1092 | lkm = trace_kernel_create_metadata(); |
| 1093 | if (lkm == NULL) { |
| 1094 | goto error; |
| 1095 | } |
| 1096 | |
| 1097 | /* Kernel tracer metadata creation */ |
| 1098 | ret = kernctl_open_metadata(session->fd, &lkm->conf->attr); |
| 1099 | if (ret < 0) { |
| 1100 | goto error_open; |
| 1101 | } |
| 1102 | |
| 1103 | lkm->fd = ret; |
| 1104 | lkm->key = ++next_kernel_channel_key; |
| 1105 | /* Prevent fd duplication after execlp() */ |
| 1106 | ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC); |
| 1107 | if (ret < 0) { |
| 1108 | PERROR("fcntl session fd"); |
| 1109 | } |
| 1110 | |
| 1111 | session->metadata = lkm; |
| 1112 | |
| 1113 | DBG("Kernel metadata opened (fd: %d)", lkm->fd); |
| 1114 | |
| 1115 | return 0; |
| 1116 | |
| 1117 | error_open: |
| 1118 | trace_kernel_destroy_metadata(lkm); |
| 1119 | error: |
| 1120 | return -1; |
| 1121 | } |
| 1122 | |
| 1123 | /* |
| 1124 | * Start tracing session. |
| 1125 | */ |
| 1126 | int kernel_start_session(struct ltt_kernel_session *session) |
| 1127 | { |
| 1128 | int ret; |
| 1129 | |
| 1130 | assert(session); |
| 1131 | |
| 1132 | ret = kernctl_start_session(session->fd); |
| 1133 | if (ret < 0) { |
| 1134 | PERROR("ioctl start session"); |
| 1135 | goto error; |
| 1136 | } |
| 1137 | |
| 1138 | DBG("Kernel session started"); |
| 1139 | |
| 1140 | return 0; |
| 1141 | |
| 1142 | error: |
| 1143 | return ret; |
| 1144 | } |
| 1145 | |
| 1146 | /* |
| 1147 | * Make a kernel wait to make sure in-flight probe have completed. |
| 1148 | */ |
| 1149 | void kernel_wait_quiescent(void) |
| 1150 | { |
| 1151 | int ret; |
| 1152 | int fd = kernel_tracer_fd; |
| 1153 | |
| 1154 | DBG("Kernel quiescent wait on %d", fd); |
| 1155 | |
| 1156 | ret = kernctl_wait_quiescent(fd); |
| 1157 | if (ret < 0) { |
| 1158 | PERROR("wait quiescent ioctl"); |
| 1159 | ERR("Kernel quiescent wait failed"); |
| 1160 | } |
| 1161 | } |
| 1162 | |
| 1163 | /* |
| 1164 | * Force flush buffer of metadata. |
| 1165 | */ |
| 1166 | int kernel_metadata_flush_buffer(int fd) |
| 1167 | { |
| 1168 | int ret; |
| 1169 | |
| 1170 | DBG("Kernel flushing metadata buffer on fd %d", fd); |
| 1171 | |
| 1172 | ret = kernctl_buffer_flush(fd); |
| 1173 | if (ret < 0) { |
| 1174 | ERR("Fail to flush metadata buffers %d (ret: %d)", fd, ret); |
| 1175 | } |
| 1176 | |
| 1177 | return 0; |
| 1178 | } |
| 1179 | |
| 1180 | /* |
| 1181 | * Force flush buffer for channel. |
| 1182 | */ |
| 1183 | int kernel_flush_buffer(struct ltt_kernel_channel *channel) |
| 1184 | { |
| 1185 | int ret; |
| 1186 | struct ltt_kernel_stream *stream; |
| 1187 | |
| 1188 | assert(channel); |
| 1189 | |
| 1190 | DBG("Flush buffer for channel %s", channel->channel->name); |
| 1191 | |
| 1192 | cds_list_for_each_entry(stream, &channel->stream_list.head, list) { |
| 1193 | DBG("Flushing channel stream %d", stream->fd); |
| 1194 | ret = kernctl_buffer_flush(stream->fd); |
| 1195 | if (ret < 0) { |
| 1196 | PERROR("ioctl"); |
| 1197 | ERR("Fail to flush buffer for stream %d (ret: %d)", |
| 1198 | stream->fd, ret); |
| 1199 | } |
| 1200 | } |
| 1201 | |
| 1202 | return 0; |
| 1203 | } |
| 1204 | |
| 1205 | /* |
| 1206 | * Stop tracing session. |
| 1207 | */ |
| 1208 | int kernel_stop_session(struct ltt_kernel_session *session) |
| 1209 | { |
| 1210 | int ret; |
| 1211 | |
| 1212 | assert(session); |
| 1213 | |
| 1214 | ret = kernctl_stop_session(session->fd); |
| 1215 | if (ret < 0) { |
| 1216 | goto error; |
| 1217 | } |
| 1218 | |
| 1219 | DBG("Kernel session stopped"); |
| 1220 | |
| 1221 | return 0; |
| 1222 | |
| 1223 | error: |
| 1224 | return ret; |
| 1225 | } |
| 1226 | |
| 1227 | /* |
| 1228 | * Open stream of channel, register it to the kernel tracer and add it |
| 1229 | * to the stream list of the channel. |
| 1230 | * |
| 1231 | * Note: given that the streams may appear in random order wrt CPU |
| 1232 | * number (e.g. cpu hotplug), the index value of the stream number in |
| 1233 | * the stream name is not necessarily linked to the CPU number. |
| 1234 | * |
| 1235 | * Return the number of created stream. Else, a negative value. |
| 1236 | */ |
| 1237 | int kernel_open_channel_stream(struct ltt_kernel_channel *channel) |
| 1238 | { |
| 1239 | int ret; |
| 1240 | struct ltt_kernel_stream *lks; |
| 1241 | |
| 1242 | assert(channel); |
| 1243 | |
| 1244 | while ((ret = kernctl_create_stream(channel->fd)) >= 0) { |
| 1245 | lks = trace_kernel_create_stream(channel->channel->name, |
| 1246 | channel->stream_count); |
| 1247 | if (lks == NULL) { |
| 1248 | ret = close(ret); |
| 1249 | if (ret) { |
| 1250 | PERROR("close"); |
| 1251 | } |
| 1252 | goto error; |
| 1253 | } |
| 1254 | |
| 1255 | lks->fd = ret; |
| 1256 | /* Prevent fd duplication after execlp() */ |
| 1257 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 1258 | if (ret < 0) { |
| 1259 | PERROR("fcntl session fd"); |
| 1260 | } |
| 1261 | |
| 1262 | lks->tracefile_size = channel->channel->attr.tracefile_size; |
| 1263 | lks->tracefile_count = channel->channel->attr.tracefile_count; |
| 1264 | |
| 1265 | /* Add stream to channel stream list */ |
| 1266 | cds_list_add(&lks->list, &channel->stream_list.head); |
| 1267 | channel->stream_count++; |
| 1268 | |
| 1269 | DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd, |
| 1270 | lks->state); |
| 1271 | } |
| 1272 | |
| 1273 | return channel->stream_count; |
| 1274 | |
| 1275 | error: |
| 1276 | return -1; |
| 1277 | } |
| 1278 | |
| 1279 | /* |
| 1280 | * Open the metadata stream and set it to the kernel session. |
| 1281 | */ |
| 1282 | int kernel_open_metadata_stream(struct ltt_kernel_session *session) |
| 1283 | { |
| 1284 | int ret; |
| 1285 | |
| 1286 | assert(session); |
| 1287 | |
| 1288 | ret = kernctl_create_stream(session->metadata->fd); |
| 1289 | if (ret < 0) { |
| 1290 | PERROR("kernel create metadata stream"); |
| 1291 | goto error; |
| 1292 | } |
| 1293 | |
| 1294 | DBG("Kernel metadata stream created (fd: %d)", ret); |
| 1295 | session->metadata_stream_fd = ret; |
| 1296 | /* Prevent fd duplication after execlp() */ |
| 1297 | ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC); |
| 1298 | if (ret < 0) { |
| 1299 | PERROR("fcntl session fd"); |
| 1300 | } |
| 1301 | |
| 1302 | return 0; |
| 1303 | |
| 1304 | error: |
| 1305 | return -1; |
| 1306 | } |
| 1307 | |
| 1308 | /* |
| 1309 | * Get the event list from the kernel tracer and return the number of elements. |
| 1310 | */ |
| 1311 | ssize_t kernel_list_events(struct lttng_event **events) |
| 1312 | { |
| 1313 | int fd, ret; |
| 1314 | char *event; |
| 1315 | size_t nbmem, count = 0; |
| 1316 | FILE *fp; |
| 1317 | struct lttng_event *elist; |
| 1318 | |
| 1319 | assert(events); |
| 1320 | |
| 1321 | fd = kernctl_tracepoint_list(kernel_tracer_fd); |
| 1322 | if (fd < 0) { |
| 1323 | PERROR("kernel tracepoint list"); |
| 1324 | goto error; |
| 1325 | } |
| 1326 | |
| 1327 | fp = fdopen(fd, "r"); |
| 1328 | if (fp == NULL) { |
| 1329 | PERROR("kernel tracepoint list fdopen"); |
| 1330 | goto error_fp; |
| 1331 | } |
| 1332 | |
| 1333 | /* |
| 1334 | * Init memory size counter |
| 1335 | * See kernel-ctl.h for explanation of this value |
| 1336 | */ |
| 1337 | nbmem = KERNEL_EVENT_INIT_LIST_SIZE; |
| 1338 | elist = zmalloc(sizeof(struct lttng_event) * nbmem); |
| 1339 | if (elist == NULL) { |
| 1340 | PERROR("alloc list events"); |
| 1341 | count = -ENOMEM; |
| 1342 | goto end; |
| 1343 | } |
| 1344 | |
| 1345 | while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) { |
| 1346 | if (count >= nbmem) { |
| 1347 | struct lttng_event *new_elist; |
| 1348 | size_t new_nbmem; |
| 1349 | |
| 1350 | new_nbmem = nbmem << 1; |
| 1351 | DBG("Reallocating event list from %zu to %zu bytes", |
| 1352 | nbmem, new_nbmem); |
| 1353 | new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event)); |
| 1354 | if (new_elist == NULL) { |
| 1355 | PERROR("realloc list events"); |
| 1356 | free(event); |
| 1357 | free(elist); |
| 1358 | count = -ENOMEM; |
| 1359 | goto end; |
| 1360 | } |
| 1361 | /* Zero the new memory */ |
| 1362 | memset(new_elist + nbmem, 0, |
| 1363 | (new_nbmem - nbmem) * sizeof(struct lttng_event)); |
| 1364 | nbmem = new_nbmem; |
| 1365 | elist = new_elist; |
| 1366 | } |
| 1367 | strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN); |
| 1368 | elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 1369 | elist[count].enabled = -1; |
| 1370 | count++; |
| 1371 | free(event); |
| 1372 | } |
| 1373 | |
| 1374 | *events = elist; |
| 1375 | DBG("Kernel list events done (%zu events)", count); |
| 1376 | end: |
| 1377 | ret = fclose(fp); /* closes both fp and fd */ |
| 1378 | if (ret) { |
| 1379 | PERROR("fclose"); |
| 1380 | } |
| 1381 | return count; |
| 1382 | |
| 1383 | error_fp: |
| 1384 | ret = close(fd); |
| 1385 | if (ret) { |
| 1386 | PERROR("close"); |
| 1387 | } |
| 1388 | error: |
| 1389 | return -1; |
| 1390 | } |
| 1391 | |
| 1392 | /* |
| 1393 | * Get kernel version and validate it. |
| 1394 | */ |
| 1395 | int kernel_validate_version(struct lttng_kernel_tracer_version *version, |
| 1396 | struct lttng_kernel_tracer_abi_version *abi_version) |
| 1397 | { |
| 1398 | int ret; |
| 1399 | |
| 1400 | ret = kernctl_tracer_version(kernel_tracer_fd, version); |
| 1401 | if (ret < 0) { |
| 1402 | ERR("Failed to retrieve the lttng-modules version"); |
| 1403 | goto error; |
| 1404 | } |
| 1405 | |
| 1406 | /* Validate version */ |
| 1407 | if (version->major != VERSION_MAJOR) { |
| 1408 | ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)", |
| 1409 | version->major, VERSION_MAJOR); |
| 1410 | goto error_version; |
| 1411 | } |
| 1412 | ret = kernctl_tracer_abi_version(kernel_tracer_fd, abi_version); |
| 1413 | if (ret < 0) { |
| 1414 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 1415 | goto error; |
| 1416 | } |
| 1417 | if (abi_version->major != LTTNG_MODULES_ABI_MAJOR_VERSION) { |
| 1418 | ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)", |
| 1419 | abi_version->major, abi_version->minor, |
| 1420 | LTTNG_MODULES_ABI_MAJOR_VERSION); |
| 1421 | goto error; |
| 1422 | } |
| 1423 | DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)", |
| 1424 | version->major, version->minor, |
| 1425 | abi_version->major, abi_version->minor); |
| 1426 | return 0; |
| 1427 | |
| 1428 | error_version: |
| 1429 | ret = -1; |
| 1430 | |
| 1431 | error: |
| 1432 | ERR("Kernel tracer version check failed; kernel tracing will not be available"); |
| 1433 | return ret; |
| 1434 | } |
| 1435 | |
| 1436 | /* |
| 1437 | * Kernel work-arounds called at the start of sessiond main(). |
| 1438 | */ |
| 1439 | int init_kernel_workarounds(void) |
| 1440 | { |
| 1441 | int ret; |
| 1442 | FILE *fp; |
| 1443 | |
| 1444 | /* |
| 1445 | * boot_id needs to be read once before being used concurrently |
| 1446 | * to deal with a Linux kernel race. A fix is proposed for |
| 1447 | * upstream, but the work-around is needed for older kernels. |
| 1448 | */ |
| 1449 | fp = fopen("/proc/sys/kernel/random/boot_id", "r"); |
| 1450 | if (!fp) { |
| 1451 | goto end_boot_id; |
| 1452 | } |
| 1453 | while (!feof(fp)) { |
| 1454 | char buf[37] = ""; |
| 1455 | |
| 1456 | ret = fread(buf, 1, sizeof(buf), fp); |
| 1457 | if (ret < 0) { |
| 1458 | /* Ignore error, we don't really care */ |
| 1459 | } |
| 1460 | } |
| 1461 | ret = fclose(fp); |
| 1462 | if (ret) { |
| 1463 | PERROR("fclose"); |
| 1464 | } |
| 1465 | end_boot_id: |
| 1466 | return 0; |
| 1467 | } |
| 1468 | |
| 1469 | /* |
| 1470 | * Teardown of a kernel session, keeping data required by destroy notifiers. |
| 1471 | */ |
| 1472 | void kernel_destroy_session(struct ltt_kernel_session *ksess) |
| 1473 | { |
| 1474 | struct lttng_trace_chunk *trace_chunk; |
| 1475 | |
| 1476 | if (ksess == NULL) { |
| 1477 | DBG3("No kernel session when tearing down session"); |
| 1478 | return; |
| 1479 | } |
| 1480 | |
| 1481 | DBG("Tearing down kernel session"); |
| 1482 | trace_chunk = ksess->current_trace_chunk; |
| 1483 | |
| 1484 | /* |
| 1485 | * Destroy channels on the consumer if at least one FD has been sent and we |
| 1486 | * are in no output mode because the streams are in *no* monitor mode so we |
| 1487 | * have to send a command to clean them up or else they leaked. |
| 1488 | */ |
| 1489 | if (!ksess->output_traces && ksess->consumer_fds_sent) { |
| 1490 | int ret; |
| 1491 | struct consumer_socket *socket; |
| 1492 | struct lttng_ht_iter iter; |
| 1493 | |
| 1494 | /* For each consumer socket. */ |
| 1495 | rcu_read_lock(); |
| 1496 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1497 | socket, node.node) { |
| 1498 | struct ltt_kernel_channel *chan; |
| 1499 | |
| 1500 | /* For each channel, ask the consumer to destroy it. */ |
| 1501 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1502 | ret = kernel_consumer_destroy_channel(socket, chan); |
| 1503 | if (ret < 0) { |
| 1504 | /* Consumer is probably dead. Use next socket. */ |
| 1505 | continue; |
| 1506 | } |
| 1507 | } |
| 1508 | } |
| 1509 | rcu_read_unlock(); |
| 1510 | } |
| 1511 | |
| 1512 | /* Close any relayd session */ |
| 1513 | consumer_output_send_destroy_relayd(ksess->consumer); |
| 1514 | |
| 1515 | trace_kernel_destroy_session(ksess); |
| 1516 | lttng_trace_chunk_put(trace_chunk); |
| 1517 | } |
| 1518 | |
| 1519 | /* Teardown of data required by destroy notifiers. */ |
| 1520 | void kernel_free_session(struct ltt_kernel_session *ksess) |
| 1521 | { |
| 1522 | if (ksess == NULL) { |
| 1523 | return; |
| 1524 | } |
| 1525 | trace_kernel_free_session(ksess); |
| 1526 | } |
| 1527 | |
| 1528 | /* |
| 1529 | * Destroy a kernel channel object. It does not do anything on the tracer side. |
| 1530 | */ |
| 1531 | void kernel_destroy_channel(struct ltt_kernel_channel *kchan) |
| 1532 | { |
| 1533 | struct ltt_kernel_session *ksess = NULL; |
| 1534 | |
| 1535 | assert(kchan); |
| 1536 | assert(kchan->channel); |
| 1537 | |
| 1538 | DBG3("Kernel destroy channel %s", kchan->channel->name); |
| 1539 | |
| 1540 | /* Update channel count of associated session. */ |
| 1541 | if (kchan->session) { |
| 1542 | /* Keep pointer reference so we can update it after the destroy. */ |
| 1543 | ksess = kchan->session; |
| 1544 | } |
| 1545 | |
| 1546 | trace_kernel_destroy_channel(kchan); |
| 1547 | |
| 1548 | /* |
| 1549 | * At this point the kernel channel is not visible anymore. This is safe |
| 1550 | * since in order to work on a visible kernel session, the tracing session |
| 1551 | * lock (ltt_session.lock) MUST be acquired. |
| 1552 | */ |
| 1553 | if (ksess) { |
| 1554 | ksess->channel_count--; |
| 1555 | } |
| 1556 | } |
| 1557 | |
| 1558 | /* |
| 1559 | * Take a snapshot for a given kernel session. |
| 1560 | * |
| 1561 | * Return LTTNG_OK on success or else return a LTTNG_ERR code. |
| 1562 | */ |
| 1563 | enum lttng_error_code kernel_snapshot_record( |
| 1564 | struct ltt_kernel_session *ksess, |
| 1565 | const struct consumer_output *output, int wait, |
| 1566 | uint64_t nb_packets_per_stream) |
| 1567 | { |
| 1568 | int err, ret, saved_metadata_fd; |
| 1569 | enum lttng_error_code status = LTTNG_OK; |
| 1570 | struct consumer_socket *socket; |
| 1571 | struct lttng_ht_iter iter; |
| 1572 | struct ltt_kernel_metadata *saved_metadata; |
| 1573 | char *trace_path = NULL; |
| 1574 | size_t consumer_path_offset = 0; |
| 1575 | |
| 1576 | assert(ksess); |
| 1577 | assert(ksess->consumer); |
| 1578 | assert(output); |
| 1579 | |
| 1580 | DBG("Kernel snapshot record started"); |
| 1581 | |
| 1582 | /* Save current metadata since the following calls will change it. */ |
| 1583 | saved_metadata = ksess->metadata; |
| 1584 | saved_metadata_fd = ksess->metadata_stream_fd; |
| 1585 | |
| 1586 | rcu_read_lock(); |
| 1587 | |
| 1588 | ret = kernel_open_metadata(ksess); |
| 1589 | if (ret < 0) { |
| 1590 | status = LTTNG_ERR_KERN_META_FAIL; |
| 1591 | goto error; |
| 1592 | } |
| 1593 | |
| 1594 | ret = kernel_open_metadata_stream(ksess); |
| 1595 | if (ret < 0) { |
| 1596 | status = LTTNG_ERR_KERN_META_FAIL; |
| 1597 | goto error_open_stream; |
| 1598 | } |
| 1599 | |
| 1600 | trace_path = setup_channel_trace_path(ksess->consumer, |
| 1601 | DEFAULT_KERNEL_TRACE_DIR, &consumer_path_offset); |
| 1602 | if (!trace_path) { |
| 1603 | status = LTTNG_ERR_INVALID; |
| 1604 | goto error; |
| 1605 | } |
| 1606 | /* Send metadata to consumer and snapshot everything. */ |
| 1607 | cds_lfht_for_each_entry(output->socks->ht, &iter.iter, |
| 1608 | socket, node.node) { |
| 1609 | struct ltt_kernel_channel *chan; |
| 1610 | |
| 1611 | pthread_mutex_lock(socket->lock); |
| 1612 | /* This stream must not be monitored by the consumer. */ |
| 1613 | ret = kernel_consumer_add_metadata(socket, ksess, 0); |
| 1614 | pthread_mutex_unlock(socket->lock); |
| 1615 | if (ret < 0) { |
| 1616 | status = LTTNG_ERR_KERN_META_FAIL; |
| 1617 | goto error_consumer; |
| 1618 | } |
| 1619 | |
| 1620 | /* For each channel, ask the consumer to snapshot it. */ |
| 1621 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1622 | status = consumer_snapshot_channel(socket, chan->key, output, 0, |
| 1623 | ksess->uid, ksess->gid, |
| 1624 | &trace_path[consumer_path_offset], wait, |
| 1625 | nb_packets_per_stream); |
| 1626 | if (status != LTTNG_OK) { |
| 1627 | (void) kernel_consumer_destroy_metadata(socket, |
| 1628 | ksess->metadata); |
| 1629 | goto error_consumer; |
| 1630 | } |
| 1631 | } |
| 1632 | |
| 1633 | /* Snapshot metadata, */ |
| 1634 | status = consumer_snapshot_channel(socket, ksess->metadata->key, output, |
| 1635 | 1, ksess->uid, ksess->gid, &trace_path[consumer_path_offset], |
| 1636 | wait, 0); |
| 1637 | if (status != LTTNG_OK) { |
| 1638 | goto error_consumer; |
| 1639 | } |
| 1640 | |
| 1641 | /* |
| 1642 | * The metadata snapshot is done, ask the consumer to destroy it since |
| 1643 | * it's not monitored on the consumer side. |
| 1644 | */ |
| 1645 | (void) kernel_consumer_destroy_metadata(socket, ksess->metadata); |
| 1646 | } |
| 1647 | |
| 1648 | error_consumer: |
| 1649 | /* Close newly opened metadata stream. It's now on the consumer side. */ |
| 1650 | err = close(ksess->metadata_stream_fd); |
| 1651 | if (err < 0) { |
| 1652 | PERROR("close snapshot kernel"); |
| 1653 | } |
| 1654 | |
| 1655 | error_open_stream: |
| 1656 | trace_kernel_destroy_metadata(ksess->metadata); |
| 1657 | error: |
| 1658 | /* Restore metadata state.*/ |
| 1659 | ksess->metadata = saved_metadata; |
| 1660 | ksess->metadata_stream_fd = saved_metadata_fd; |
| 1661 | rcu_read_unlock(); |
| 1662 | free(trace_path); |
| 1663 | return status; |
| 1664 | } |
| 1665 | |
| 1666 | /* |
| 1667 | * Get the syscall mask array from the kernel tracer. |
| 1668 | * |
| 1669 | * Return 0 on success else a negative value. In both case, syscall_mask should |
| 1670 | * be freed. |
| 1671 | */ |
| 1672 | int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits) |
| 1673 | { |
| 1674 | assert(syscall_mask); |
| 1675 | assert(nr_bits); |
| 1676 | |
| 1677 | return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits); |
| 1678 | } |
| 1679 | |
| 1680 | /* |
| 1681 | * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi |
| 1682 | * version number. |
| 1683 | * |
| 1684 | * Return 1 on success, 0 when feature is not supported, negative value in case |
| 1685 | * of errors. |
| 1686 | */ |
| 1687 | int kernel_supports_ring_buffer_snapshot_sample_positions(void) |
| 1688 | { |
| 1689 | int ret = 0; // Not supported by default |
| 1690 | struct lttng_kernel_tracer_abi_version abi; |
| 1691 | |
| 1692 | ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi); |
| 1693 | if (ret < 0) { |
| 1694 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 1695 | goto error; |
| 1696 | } |
| 1697 | |
| 1698 | /* |
| 1699 | * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3 |
| 1700 | */ |
| 1701 | if (abi.major >= 2 && abi.minor >= 3) { |
| 1702 | /* Supported */ |
| 1703 | ret = 1; |
| 1704 | } else { |
| 1705 | /* Not supported */ |
| 1706 | ret = 0; |
| 1707 | } |
| 1708 | error: |
| 1709 | return ret; |
| 1710 | } |
| 1711 | |
| 1712 | /* |
| 1713 | * Check for the support of the packet sequence number via abi version number. |
| 1714 | * |
| 1715 | * Return 1 on success, 0 when feature is not supported, negative value in case |
| 1716 | * of errors. |
| 1717 | */ |
| 1718 | int kernel_supports_ring_buffer_packet_sequence_number(void) |
| 1719 | { |
| 1720 | int ret = 0; // Not supported by default |
| 1721 | struct lttng_kernel_tracer_abi_version abi; |
| 1722 | |
| 1723 | ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi); |
| 1724 | if (ret < 0) { |
| 1725 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 1726 | goto error; |
| 1727 | } |
| 1728 | |
| 1729 | /* |
| 1730 | * Packet sequence number was introduced in LTTng 2.8, |
| 1731 | * lttng-modules ABI 2.1. |
| 1732 | */ |
| 1733 | if (abi.major >= 2 && abi.minor >= 1) { |
| 1734 | /* Supported */ |
| 1735 | ret = 1; |
| 1736 | } else { |
| 1737 | /* Not supported */ |
| 1738 | ret = 0; |
| 1739 | } |
| 1740 | error: |
| 1741 | return ret; |
| 1742 | } |
| 1743 | |
| 1744 | /* |
| 1745 | * Rotate a kernel session. |
| 1746 | * |
| 1747 | * Return LTTNG_OK on success or else an LTTng error code. |
| 1748 | */ |
| 1749 | enum lttng_error_code kernel_rotate_session(struct ltt_session *session) |
| 1750 | { |
| 1751 | int ret; |
| 1752 | enum lttng_error_code status = LTTNG_OK; |
| 1753 | struct consumer_socket *socket; |
| 1754 | struct lttng_ht_iter iter; |
| 1755 | struct ltt_kernel_session *ksess = session->kernel_session; |
| 1756 | |
| 1757 | assert(ksess); |
| 1758 | assert(ksess->consumer); |
| 1759 | |
| 1760 | DBG("Rotate kernel session %s started (session %" PRIu64 ")", |
| 1761 | session->name, session->id); |
| 1762 | |
| 1763 | rcu_read_lock(); |
| 1764 | |
| 1765 | /* |
| 1766 | * Note that this loop will end after one iteration given that there is |
| 1767 | * only one kernel consumer. |
| 1768 | */ |
| 1769 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1770 | socket, node.node) { |
| 1771 | struct ltt_kernel_channel *chan; |
| 1772 | |
| 1773 | /* For each channel, ask the consumer to rotate it. */ |
| 1774 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1775 | DBG("Rotate kernel channel %" PRIu64 ", session %s", |
| 1776 | chan->key, session->name); |
| 1777 | ret = consumer_rotate_channel(socket, chan->key, |
| 1778 | ksess->uid, ksess->gid, ksess->consumer, |
| 1779 | /* is_metadata_channel */ false); |
| 1780 | if (ret < 0) { |
| 1781 | status = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1782 | goto error; |
| 1783 | } |
| 1784 | } |
| 1785 | |
| 1786 | /* |
| 1787 | * Rotate the metadata channel. |
| 1788 | */ |
| 1789 | ret = consumer_rotate_channel(socket, ksess->metadata->key, |
| 1790 | ksess->uid, ksess->gid, ksess->consumer, |
| 1791 | /* is_metadata_channel */ true); |
| 1792 | if (ret < 0) { |
| 1793 | status = LTTNG_ERR_KERN_CONSUMER_FAIL; |
| 1794 | goto error; |
| 1795 | } |
| 1796 | } |
| 1797 | |
| 1798 | error: |
| 1799 | rcu_read_unlock(); |
| 1800 | return status; |
| 1801 | } |
| 1802 | |
| 1803 | enum lttng_error_code kernel_create_channel_subdirectories( |
| 1804 | const struct ltt_kernel_session *ksess) |
| 1805 | { |
| 1806 | enum lttng_error_code ret = LTTNG_OK; |
| 1807 | enum lttng_trace_chunk_status chunk_status; |
| 1808 | |
| 1809 | rcu_read_lock(); |
| 1810 | assert(ksess->current_trace_chunk); |
| 1811 | |
| 1812 | /* |
| 1813 | * Create the index subdirectory which will take care |
| 1814 | * of implicitly creating the channel's path. |
| 1815 | */ |
| 1816 | chunk_status = lttng_trace_chunk_create_subdirectory( |
| 1817 | ksess->current_trace_chunk, |
| 1818 | DEFAULT_KERNEL_TRACE_DIR "/" DEFAULT_INDEX_DIR); |
| 1819 | if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { |
| 1820 | ret = LTTNG_ERR_CREATE_DIR_FAIL; |
| 1821 | goto error; |
| 1822 | } |
| 1823 | error: |
| 1824 | rcu_read_unlock(); |
| 1825 | return ret; |
| 1826 | } |
| 1827 | |
| 1828 | /* |
| 1829 | * Setup necessary data for kernel tracer action. |
| 1830 | */ |
| 1831 | LTTNG_HIDDEN |
| 1832 | int init_kernel_tracer(void) |
| 1833 | { |
| 1834 | int ret; |
| 1835 | bool is_root = !getuid(); |
| 1836 | |
| 1837 | /* Modprobe lttng kernel modules */ |
| 1838 | ret = modprobe_lttng_control(); |
| 1839 | if (ret < 0) { |
| 1840 | goto error; |
| 1841 | } |
| 1842 | |
| 1843 | /* Open debugfs lttng */ |
| 1844 | kernel_tracer_fd = open(module_proc_lttng, O_RDWR); |
| 1845 | if (kernel_tracer_fd < 0) { |
| 1846 | DBG("Failed to open %s", module_proc_lttng); |
| 1847 | goto error_open; |
| 1848 | } |
| 1849 | |
| 1850 | /* Validate kernel version */ |
| 1851 | ret = kernel_validate_version(&kernel_tracer_version, |
| 1852 | &kernel_tracer_abi_version); |
| 1853 | if (ret < 0) { |
| 1854 | goto error_version; |
| 1855 | } |
| 1856 | |
| 1857 | ret = modprobe_lttng_data(); |
| 1858 | if (ret < 0) { |
| 1859 | goto error_modules; |
| 1860 | } |
| 1861 | |
| 1862 | ret = kernel_supports_ring_buffer_snapshot_sample_positions(); |
| 1863 | if (ret < 0) { |
| 1864 | goto error_modules; |
| 1865 | } |
| 1866 | if (ret < 1) { |
| 1867 | WARN("Kernel tracer does not support buffer monitoring. " |
| 1868 | "The monitoring timer of channels in the kernel domain " |
| 1869 | "will be set to 0 (disabled)."); |
| 1870 | } |
| 1871 | |
| 1872 | ret = kernel_create_trigger_group(&kernel_tracer_trigger_group_fd); |
| 1873 | if (ret < 0) { |
| 1874 | /* TODO: error handling if it is not supported etc. */ |
| 1875 | WARN("Failed trigger group creation"); |
| 1876 | kernel_tracer_trigger_group_fd = -1; |
| 1877 | /* This is not fatal */ |
| 1878 | } else { |
| 1879 | ret = kernel_create_trigger_group_notification_fd(&kernel_tracer_trigger_group_notification_fd); |
| 1880 | if (ret < 0) { |
| 1881 | goto error_modules; |
| 1882 | } |
| 1883 | } |
| 1884 | |
| 1885 | CDS_INIT_LIST_HEAD(&kernel_tracer_token_list.head); |
| 1886 | |
| 1887 | DBG("Kernel tracer fd %d", kernel_tracer_fd); |
| 1888 | DBG("Kernel tracer trigger group fd %d", kernel_tracer_trigger_group_fd); |
| 1889 | DBG("Kernel tracer trigger group notificationi fd %d", kernel_tracer_trigger_group_notification_fd); |
| 1890 | |
| 1891 | ret = syscall_init_table(kernel_tracer_fd); |
| 1892 | if (ret < 0) { |
| 1893 | ERR("Unable to populate syscall table. Syscall tracing won't " |
| 1894 | "work for this session daemon."); |
| 1895 | } |
| 1896 | |
| 1897 | return 0; |
| 1898 | |
| 1899 | error_version: |
| 1900 | modprobe_remove_lttng_control(); |
| 1901 | ret = close(kernel_tracer_fd); |
| 1902 | if (ret) { |
| 1903 | PERROR("close"); |
| 1904 | } |
| 1905 | kernel_tracer_fd = -1; |
| 1906 | return LTTNG_ERR_KERN_VERSION; |
| 1907 | |
| 1908 | error_modules: |
| 1909 | ret = close(kernel_tracer_fd); |
| 1910 | if (ret) { |
| 1911 | PERROR("close"); |
| 1912 | } |
| 1913 | |
| 1914 | error_open: |
| 1915 | modprobe_remove_lttng_control(); |
| 1916 | |
| 1917 | error: |
| 1918 | WARN("No kernel tracer available"); |
| 1919 | kernel_tracer_fd = -1; |
| 1920 | if (!is_root) { |
| 1921 | return LTTNG_ERR_NEED_ROOT_SESSIOND; |
| 1922 | } else { |
| 1923 | return LTTNG_ERR_KERN_NA; |
| 1924 | } |
| 1925 | } |
| 1926 | |
| 1927 | LTTNG_HIDDEN |
| 1928 | void cleanup_kernel_tracer(void) |
| 1929 | { |
| 1930 | int ret; |
| 1931 | |
| 1932 | struct ltt_kernel_token_event_rule *rule, *rtmp; |
| 1933 | cds_list_for_each_entry_safe(rule, rtmp, &kernel_tracer_token_list.head, list) { |
| 1934 | kernel_disable_token_event_rule(rule); |
| 1935 | trace_kernel_destroy_token_event_rule(rule); |
| 1936 | } |
| 1937 | |
| 1938 | DBG2("Closing kernel trigger group notification fd"); |
| 1939 | if (kernel_tracer_trigger_group_notification_fd >= 0) { |
| 1940 | ret = close(kernel_tracer_trigger_group_notification_fd); |
| 1941 | if (ret) { |
| 1942 | PERROR("close"); |
| 1943 | } |
| 1944 | kernel_tracer_trigger_group_notification_fd = -1; |
| 1945 | } |
| 1946 | |
| 1947 | /* TODO: do we iterate over the list to remove all token? */ |
| 1948 | DBG2("Closing kernel trigger group fd"); |
| 1949 | if (kernel_tracer_trigger_group_fd >= 0) { |
| 1950 | ret = close(kernel_tracer_trigger_group_fd); |
| 1951 | if (ret) { |
| 1952 | PERROR("close"); |
| 1953 | } |
| 1954 | kernel_tracer_trigger_group_fd = -1; |
| 1955 | } |
| 1956 | |
| 1957 | DBG2("Closing kernel fd"); |
| 1958 | if (kernel_tracer_fd >= 0) { |
| 1959 | ret = close(kernel_tracer_fd); |
| 1960 | if (ret) { |
| 1961 | PERROR("close"); |
| 1962 | } |
| 1963 | kernel_tracer_fd = -1; |
| 1964 | } |
| 1965 | |
| 1966 | |
| 1967 | DBG("Unloading kernel modules"); |
| 1968 | modprobe_remove_lttng_all(); |
| 1969 | free(syscall_table); |
| 1970 | } |
| 1971 | |
| 1972 | LTTNG_HIDDEN |
| 1973 | bool kernel_tracer_is_initialized(void) |
| 1974 | { |
| 1975 | return kernel_tracer_fd >= 0; |
| 1976 | } |
| 1977 | |
| 1978 | /* |
| 1979 | * Clear a kernel session. |
| 1980 | * |
| 1981 | * Return LTTNG_OK on success or else an LTTng error code. |
| 1982 | */ |
| 1983 | enum lttng_error_code kernel_clear_session(struct ltt_session *session) |
| 1984 | { |
| 1985 | int ret; |
| 1986 | enum lttng_error_code status = LTTNG_OK; |
| 1987 | struct consumer_socket *socket; |
| 1988 | struct lttng_ht_iter iter; |
| 1989 | struct ltt_kernel_session *ksess = session->kernel_session; |
| 1990 | |
| 1991 | assert(ksess); |
| 1992 | assert(ksess->consumer); |
| 1993 | |
| 1994 | DBG("Clear kernel session %s (session %" PRIu64 ")", |
| 1995 | session->name, session->id); |
| 1996 | |
| 1997 | rcu_read_lock(); |
| 1998 | |
| 1999 | if (ksess->active) { |
| 2000 | ERR("Expecting inactive session %s (%" PRIu64 ")", session->name, session->id); |
| 2001 | status = LTTNG_ERR_FATAL; |
| 2002 | goto end; |
| 2003 | } |
| 2004 | |
| 2005 | /* |
| 2006 | * Note that this loop will end after one iteration given that there is |
| 2007 | * only one kernel consumer. |
| 2008 | */ |
| 2009 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 2010 | socket, node.node) { |
| 2011 | struct ltt_kernel_channel *chan; |
| 2012 | |
| 2013 | /* For each channel, ask the consumer to clear it. */ |
| 2014 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 2015 | DBG("Clear kernel channel %" PRIu64 ", session %s", |
| 2016 | chan->key, session->name); |
| 2017 | ret = consumer_clear_channel(socket, chan->key); |
| 2018 | if (ret < 0) { |
| 2019 | goto error; |
| 2020 | } |
| 2021 | } |
| 2022 | |
| 2023 | if (!ksess->metadata) { |
| 2024 | /* |
| 2025 | * Nothing to do for the metadata. |
| 2026 | * This is a snapshot session. |
| 2027 | * The metadata is genererated on the fly. |
| 2028 | */ |
| 2029 | continue; |
| 2030 | } |
| 2031 | |
| 2032 | /* |
| 2033 | * Clear the metadata channel. |
| 2034 | * Metadata channel is not cleared per se but we still need to |
| 2035 | * perform a rotation operation on it behind the scene. |
| 2036 | */ |
| 2037 | ret = consumer_clear_channel(socket, ksess->metadata->key); |
| 2038 | if (ret < 0) { |
| 2039 | goto error; |
| 2040 | } |
| 2041 | } |
| 2042 | |
| 2043 | goto end; |
| 2044 | error: |
| 2045 | switch (-ret) { |
| 2046 | case LTTCOMM_CONSUMERD_RELAYD_CLEAR_DISALLOWED: |
| 2047 | status = LTTNG_ERR_CLEAR_RELAY_DISALLOWED; |
| 2048 | break; |
| 2049 | default: |
| 2050 | status = LTTNG_ERR_CLEAR_FAIL_CONSUMER; |
| 2051 | break; |
| 2052 | } |
| 2053 | end: |
| 2054 | rcu_read_unlock(); |
| 2055 | return status; |
| 2056 | } |
| 2057 | |
| 2058 | enum lttng_error_code kernel_create_trigger_group_notification_fd( |
| 2059 | int *trigger_group_notification_fd) |
| 2060 | { |
| 2061 | enum lttng_error_code ret = LTTNG_OK; |
| 2062 | int local_fd = -1; |
| 2063 | |
| 2064 | assert(trigger_group_notification_fd); |
| 2065 | |
| 2066 | ret = kernctl_create_trigger_group_notification_fd(kernel_tracer_trigger_group_fd); |
| 2067 | if (ret < 0) { |
| 2068 | PERROR("ioctl kernel create trigger group"); |
| 2069 | ret = -1; |
| 2070 | goto error; |
| 2071 | } |
| 2072 | |
| 2073 | /* Store locally */ |
| 2074 | local_fd = ret; |
| 2075 | |
| 2076 | /* Prevent fd duplication after execlp() */ |
| 2077 | ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC); |
| 2078 | if (ret < 0) { |
| 2079 | PERROR("fcntl session fd"); |
| 2080 | } |
| 2081 | |
| 2082 | DBG("Kernel trigger group notification created (fd: %d)", |
| 2083 | local_fd); |
| 2084 | ret = 0; |
| 2085 | |
| 2086 | error: |
| 2087 | *trigger_group_notification_fd = local_fd; |
| 2088 | return ret; |
| 2089 | } |
| 2090 | |
| 2091 | enum lttng_error_code kernel_destroy_trigger_group_notification_fd( |
| 2092 | int trigger_group_notification_fd) |
| 2093 | { |
| 2094 | enum lttng_error_code ret = LTTNG_OK; |
| 2095 | DBG("Closing trigger group notification fd %d", trigger_group_notification_fd); |
| 2096 | if (trigger_group_notification_fd >= 0) { |
| 2097 | ret = close(trigger_group_notification_fd); |
| 2098 | if (ret) { |
| 2099 | PERROR("close"); |
| 2100 | } |
| 2101 | } |
| 2102 | return ret; |
| 2103 | } |
| 2104 | |
| 2105 | static int kernel_create_token_event_rule(struct lttng_event_rule *rule, |
| 2106 | const struct lttng_credentials *creds, uint64_t token) |
| 2107 | { |
| 2108 | int err, fd; |
| 2109 | enum lttng_error_code ret; |
| 2110 | struct ltt_kernel_token_event_rule *event; |
| 2111 | struct lttng_kernel_trigger trigger; |
| 2112 | |
| 2113 | assert(rule); |
| 2114 | |
| 2115 | ret = trace_kernel_create_token_event_rule(rule, token, &event); |
| 2116 | if (ret != LTTNG_OK) { |
| 2117 | goto error; |
| 2118 | } |
| 2119 | |
| 2120 | trace_kernel_init_trigger_from_event_rule(event->event_rule, &trigger); |
| 2121 | trigger.id = event->token; |
| 2122 | |
| 2123 | fd = kernctl_create_trigger(kernel_tracer_trigger_group_fd, &trigger); |
| 2124 | if (fd < 0) { |
| 2125 | switch (-fd) { |
| 2126 | case EEXIST: |
| 2127 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 2128 | break; |
| 2129 | case ENOSYS: |
| 2130 | WARN("Trigger type not implemented"); |
| 2131 | ret = LTTNG_ERR_KERN_EVENT_ENOSYS; |
| 2132 | break; |
| 2133 | case ENOENT: |
| 2134 | WARN("Event %s not found!", trigger.name); |
| 2135 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 2136 | break; |
| 2137 | default: |
| 2138 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 2139 | PERROR("create trigger ioctl"); |
| 2140 | } |
| 2141 | goto free_event; |
| 2142 | } |
| 2143 | |
| 2144 | event->fd = fd; |
| 2145 | /* Prevent fd duplication after execlp() */ |
| 2146 | err = fcntl(event->fd, F_SETFD, FD_CLOEXEC); |
| 2147 | if (err < 0) { |
| 2148 | PERROR("fcntl session fd"); |
| 2149 | } |
| 2150 | |
| 2151 | if (event->filter) { |
| 2152 | err = kernctl_filter(event->fd, event->filter); |
| 2153 | if (err < 0) { |
| 2154 | switch (-err) { |
| 2155 | case ENOMEM: |
| 2156 | ret = LTTNG_ERR_FILTER_NOMEM; |
| 2157 | break; |
| 2158 | default: |
| 2159 | ret = LTTNG_ERR_FILTER_INVAL; |
| 2160 | break; |
| 2161 | } |
| 2162 | goto filter_error; |
| 2163 | } |
| 2164 | } |
| 2165 | |
| 2166 | if (lttng_event_rule_get_type(event->event_rule) == |
| 2167 | LTTNG_EVENT_RULE_TYPE_UPROBE) { |
| 2168 | ret = userspace_probe_event_rule_add_callsites( |
| 2169 | rule, creds, event->fd); |
| 2170 | if (ret) { |
| 2171 | goto add_callsite_error; |
| 2172 | } |
| 2173 | } |
| 2174 | |
| 2175 | err = kernctl_enable(event->fd); |
| 2176 | if (err < 0) { |
| 2177 | switch (-err) { |
| 2178 | case EEXIST: |
| 2179 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 2180 | break; |
| 2181 | default: |
| 2182 | PERROR("enable kernel trigger"); |
| 2183 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 2184 | break; |
| 2185 | } |
| 2186 | goto enable_error; |
| 2187 | } |
| 2188 | |
| 2189 | /* Add event to event list */ |
| 2190 | cds_list_add(&event->list, &kernel_tracer_token_list.head); |
| 2191 | |
| 2192 | DBG("Trigger %s created (fd: %d)", trigger.name, event->fd); |
| 2193 | |
| 2194 | return 0; |
| 2195 | |
| 2196 | add_callsite_error: |
| 2197 | enable_error: |
| 2198 | filter_error: |
| 2199 | { |
| 2200 | int closeret; |
| 2201 | |
| 2202 | closeret = close(event->fd); |
| 2203 | if (closeret) { |
| 2204 | PERROR("close event fd"); |
| 2205 | } |
| 2206 | } |
| 2207 | free_event: |
| 2208 | free(event); |
| 2209 | error: |
| 2210 | return ret; |
| 2211 | } |
| 2212 | |
| 2213 | enum lttng_error_code kernel_update_tokens(void) |
| 2214 | { |
| 2215 | enum lttng_error_code ret = LTTNG_OK; |
| 2216 | enum lttng_trigger_status t_status; |
| 2217 | struct ltt_kernel_token_event_rule *token_event_rule_element; |
| 2218 | struct lttng_triggers *triggers; |
| 2219 | unsigned int count; |
| 2220 | |
| 2221 | /* TODO error handling */ |
| 2222 | |
| 2223 | /* Get list of token trigger from the notification thread here */ |
| 2224 | rcu_read_lock(); |
| 2225 | pthread_mutex_lock(¬ification_trigger_tokens_ht_lock); |
| 2226 | ret = notification_thread_command_get_tokens(notification_thread_handle, &triggers); |
| 2227 | if (ret != LTTNG_OK) { |
| 2228 | ret = -1; |
| 2229 | goto end; |
| 2230 | } |
| 2231 | |
| 2232 | assert(triggers); |
| 2233 | |
| 2234 | t_status = lttng_triggers_get_count(triggers, &count); |
| 2235 | if (t_status != LTTNG_TRIGGER_STATUS_OK) { |
| 2236 | ret = -1; |
| 2237 | goto end; |
| 2238 | } |
| 2239 | |
| 2240 | for (unsigned int i = 0; i < count; i++) { |
| 2241 | struct lttng_condition *condition; |
| 2242 | struct lttng_event_rule *event_rule; |
| 2243 | struct lttng_trigger *trigger; |
| 2244 | struct ltt_kernel_token_event_rule *k_token; |
| 2245 | const struct lttng_credentials *creds; |
| 2246 | uint64_t token; |
| 2247 | |
| 2248 | trigger = lttng_triggers_get_pointer_of_index(triggers, i); |
| 2249 | assert(trigger); |
| 2250 | |
| 2251 | /* TODO: error checking and type checking */ |
| 2252 | token = lttng_trigger_get_key(trigger); |
| 2253 | condition = lttng_trigger_get_condition(trigger); |
| 2254 | (void) lttng_condition_event_rule_get_rule_no_const(condition, &event_rule); |
| 2255 | |
| 2256 | if (lttng_event_rule_get_domain_type(event_rule) != LTTNG_DOMAIN_KERNEL) { |
| 2257 | /* Skip ust related trigger */ |
| 2258 | continue; |
| 2259 | } |
| 2260 | |
| 2261 | creds = lttng_trigger_get_credentials(trigger); |
| 2262 | /* Iterate over all known token trigger */ |
| 2263 | k_token = trace_kernel_find_trigger_by_token(&kernel_tracer_token_list, token); |
| 2264 | if (!k_token) { |
| 2265 | ret = kernel_create_token_event_rule(event_rule, creds, token); |
| 2266 | if (ret < 0) { |
| 2267 | goto end; |
| 2268 | } |
| 2269 | } |
| 2270 | } |
| 2271 | |
| 2272 | /* Remove all unknown trigger from the app |
| 2273 | * TODO find a way better way then this, do it on the unregister command |
| 2274 | * and be specific on the token to remove instead of going over all |
| 2275 | * trigger known to the app. This is sub optimal. |
| 2276 | */ |
| 2277 | cds_list_for_each_entry (token_event_rule_element, &kernel_tracer_token_list.head, |
| 2278 | list) { |
| 2279 | uint64_t token; |
| 2280 | bool found = false; |
| 2281 | |
| 2282 | token = token_event_rule_element->token; |
| 2283 | |
| 2284 | /* |
| 2285 | * Check if the app event trigger still exists on the |
| 2286 | * notification side. |
| 2287 | * TODO: might want to change the backing data struct of the |
| 2288 | * lttng_triggers object to allow quick lookup? |
| 2289 | * For kernel mostly all of this can be removed once we delete |
| 2290 | * on a per trigger basis. |
| 2291 | */ |
| 2292 | |
| 2293 | for (unsigned int i = 0; i < count; i++) { |
| 2294 | struct lttng_trigger *trigger; |
| 2295 | uint64_t inner_token; |
| 2296 | |
| 2297 | trigger = lttng_triggers_get_pointer_of_index( |
| 2298 | triggers, i); |
| 2299 | assert(trigger); |
| 2300 | |
| 2301 | inner_token = lttng_trigger_get_key(trigger); |
| 2302 | |
| 2303 | if (inner_token == token) { |
| 2304 | found = true; |
| 2305 | break; |
| 2306 | } |
| 2307 | } |
| 2308 | |
| 2309 | if (found) { |
| 2310 | /* Still valid */ |
| 2311 | continue; |
| 2312 | } |
| 2313 | |
| 2314 | kernel_disable_token_event_rule(token_event_rule_element); |
| 2315 | trace_kernel_destroy_token_event_rule(token_event_rule_element); |
| 2316 | } |
| 2317 | end: |
| 2318 | rcu_read_unlock(); |
| 2319 | pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock); |
| 2320 | return ret; |
| 2321 | |
| 2322 | } |
| 2323 | |
| 2324 | int kernel_get_notification_fd(void) |
| 2325 | { |
| 2326 | return kernel_tracer_trigger_group_notification_fd; |
| 2327 | } |