src/bin/lttng-sessiond/trace-kernel.c

   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 <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 #include <common/common.h>
  25 #include <common/defaults.h>
  26
  27 #include "consumer.h"
  28 #include "trace-kernel.h"
  29
  30 /*
  31  * Find the channel name for the given kernel session.
  32  */
  33 struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
  34                 char *name, struct ltt_kernel_session *session)
  35 {
  36         struct ltt_kernel_channel *chan;
  37
  38         assert(session);
  39         assert(name);
  40
  41         /*
  42          * If we receive an empty string for channel name, it means the
  43          * default channel name is requested.
  44          */
  45         if (name[0] == '\0')
  46                 name = DEFAULT_CHANNEL_NAME;
  47
  48         DBG("Trying to find channel %s", name);
  49
  50         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  51                 if (strcmp(name, chan->channel->name) == 0) {
  52                         DBG("Found channel by name %s", name);
  53                         return chan;
  54                 }
  55         }
  56
  57         return NULL;
  58 }
  59
  60 /*
  61  * Find the event for the given channel.
  62  */
  63 struct ltt_kernel_event *trace_kernel_find_event(
  64                 char *name, struct ltt_kernel_channel *channel,
  65                 enum lttng_event_type type,
  66                 struct lttng_filter_bytecode *filter)
  67 {
  68         struct ltt_kernel_event *ev;
  69         int found = 0;
  70
  71         assert(name);
  72         assert(channel);
  73
  74         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  75                 if (type != LTTNG_EVENT_ALL && ev->type != type) {
  76                         continue;
  77                 }
  78                 if (strcmp(name, ev->event->name)) {
  79                         continue;
  80                 }
  81                 if ((ev->filter && !filter) || (!ev->filter && filter)) {
  82                         continue;
  83                 }
  84                 if (ev->filter && filter) {
  85                         if (ev->filter->len != filter->len ||
  86                                         memcmp(ev->filter->data, filter->data,
  87                                                 filter->len) != 0) {
  88                                 continue;
  89                         }
  90                 }
  91                 found = 1;
  92                 break;
  93         }
  94         if (found) {
  95                 DBG("Found event %s for channel %s", name,
  96                         channel->channel->name);
  97                 return ev;
  98         } else {
  99                 return NULL;
 100         }
 101 }
 102
 103 /*
 104  * Find the event name for the given channel.
 105  */
 106 struct ltt_kernel_event *trace_kernel_get_event_by_name(
 107                 char *name, struct ltt_kernel_channel *channel,
 108                 enum lttng_event_type type)
 109 {
 110         struct ltt_kernel_event *ev;
 111         int found = 0;
 112
 113         assert(name);
 114         assert(channel);
 115
 116         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
 117                 if (type != LTTNG_EVENT_ALL && ev->type != type) {
 118                         continue;
 119                 }
 120                 if (strcmp(name, ev->event->name)) {
 121                         continue;
 122                 }
 123                 found = 1;
 124                 break;
 125         }
 126         if (found) {
 127                 DBG("Found event %s for channel %s", name,
 128                         channel->channel->name);
 129                 return ev;
 130         } else {
 131                 return NULL;
 132         }
 133 }
 134
 135 /*
 136  * Allocate and initialize a kernel session data structure.
 137  *
 138  * Return pointer to structure or NULL.
 139  */
 140 struct ltt_kernel_session *trace_kernel_create_session(void)
 141 {
 142         struct ltt_kernel_session *lks = NULL;
 143
 144         /* Allocate a new ltt kernel session */
 145         lks = zmalloc(sizeof(struct ltt_kernel_session));
 146         if (lks == NULL) {
 147                 PERROR("create kernel session zmalloc");
 148                 goto alloc_error;
 149         }
 150
 151         /* Init data structure */
 152         lks->fd = -1;
 153         lks->metadata_stream_fd = -1;
 154         lks->channel_count = 0;
 155         lks->stream_count_global = 0;
 156         lks->metadata = NULL;
 157         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 158
 159         lks->tracker_list_pid = lttng_tracker_list_create();
 160         if (!lks->tracker_list_pid) {
 161                 goto error;
 162         }
 163         lks->tracker_list_vpid = lttng_tracker_list_create();
 164         if (!lks->tracker_list_vpid) {
 165                 goto error;
 166         }
 167         lks->tracker_list_uid = lttng_tracker_list_create();
 168         if (!lks->tracker_list_uid) {
 169                 goto error;
 170         }
 171         lks->tracker_list_vuid = lttng_tracker_list_create();
 172         if (!lks->tracker_list_vuid) {
 173                 goto error;
 174         }
 175         lks->tracker_list_gid = lttng_tracker_list_create();
 176         if (!lks->tracker_list_gid) {
 177                 goto error;
 178         }
 179         lks->tracker_list_vgid = lttng_tracker_list_create();
 180         if (!lks->tracker_list_vgid) {
 181                 goto error;
 182         }
 183         lks->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 184         if (lks->consumer == NULL) {
 185                 goto error;
 186         }
 187
 188         return lks;
 189
 190 error:
 191         lttng_tracker_list_destroy(lks->tracker_list_pid);
 192         lttng_tracker_list_destroy(lks->tracker_list_vpid);
 193         lttng_tracker_list_destroy(lks->tracker_list_uid);
 194         lttng_tracker_list_destroy(lks->tracker_list_vuid);
 195         lttng_tracker_list_destroy(lks->tracker_list_gid);
 196         lttng_tracker_list_destroy(lks->tracker_list_vgid);
 197         free(lks);
 198
 199 alloc_error:
 200         return NULL;
 201 }
 202
 203 /*
 204  * Allocate and initialize a kernel channel data structure.
 205  *
 206  * Return pointer to structure or NULL.
 207  */
 208 struct ltt_kernel_channel *trace_kernel_create_channel(
 209                 struct lttng_channel *chan)
 210 {
 211         struct ltt_kernel_channel *lkc;
 212
 213         assert(chan);
 214
 215         lkc = zmalloc(sizeof(struct ltt_kernel_channel));
 216         if (lkc == NULL) {
 217                 PERROR("ltt_kernel_channel zmalloc");
 218                 goto error;
 219         }
 220
 221         lkc->channel = zmalloc(sizeof(struct lttng_channel));
 222         if (lkc->channel == NULL) {
 223                 PERROR("lttng_channel zmalloc");
 224                 free(lkc);
 225                 goto error;
 226         }
 227         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 228
 229         /*
 230          * If we receive an empty string for channel name, it means the
 231          * default channel name is requested.
 232          */
 233         if (chan->name[0] == '\0') {
 234                 strncpy(lkc->channel->name, DEFAULT_CHANNEL_NAME,
 235                         sizeof(lkc->channel->name));
 236         }
 237         lkc->channel->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 238
 239         lkc->fd = -1;
 240         lkc->stream_count = 0;
 241         lkc->event_count = 0;
 242         lkc->enabled = 1;
 243         /* Init linked list */
 244         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 245         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 246         CDS_INIT_LIST_HEAD(&lkc->ctx_list);
 247
 248         return lkc;
 249
 250 error:
 251         return NULL;
 252 }
 253
 254 /*
 255  * Allocate and init a kernel context object.
 256  *
 257  * Return the allocated object or NULL on error.
 258  */
 259 struct ltt_kernel_context *trace_kernel_create_context(
 260                 struct lttng_kernel_context *ctx)
 261 {
 262         struct ltt_kernel_context *kctx;
 263
 264         kctx = zmalloc(sizeof(*kctx));
 265         if (!kctx) {
 266                 PERROR("zmalloc kernel context");
 267                 goto error;
 268         }
 269
 270         if (ctx) {
 271                 memcpy(&kctx->ctx, ctx, sizeof(kctx->ctx));
 272         }
 273 error:
 274         return kctx;
 275 }
 276
 277 /*
 278  * Allocate and init a kernel context object from an existing kernel context
 279  * object.
 280  *
 281  * Return the allocated object or NULL on error.
 282  */
 283 struct ltt_kernel_context *trace_kernel_copy_context(
 284                 struct ltt_kernel_context *kctx)
 285 {
 286         struct ltt_kernel_context *kctx_copy;
 287
 288         assert(kctx);
 289         kctx_copy = zmalloc(sizeof(*kctx_copy));
 290         if (!kctx_copy) {
 291                 PERROR("zmalloc ltt_kernel_context");
 292                 goto error;
 293         }
 294
 295         memcpy(kctx_copy, kctx, sizeof(*kctx_copy));
 296         memset(&kctx_copy->list, 0, sizeof(kctx_copy->list));
 297
 298 error:
 299         return kctx_copy;
 300 }
 301
 302 /*
 303  * Allocate and initialize a kernel event. Set name and event type.
 304  * We own filter_expression, and filter.
 305  *
 306  * Return pointer to structure or NULL.
 307  */
 308 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev,
 309                 char *filter_expression, struct lttng_filter_bytecode *filter)
 310 {
 311         struct ltt_kernel_event *lke;
 312         struct lttng_kernel_event *attr;
 313
 314         assert(ev);
 315
 316         lke = zmalloc(sizeof(struct ltt_kernel_event));
 317         attr = zmalloc(sizeof(struct lttng_kernel_event));
 318         if (lke == NULL || attr == NULL) {
 319                 PERROR("kernel event zmalloc");
 320                 goto error;
 321         }
 322
 323         switch (ev->type) {
 324         case LTTNG_EVENT_PROBE:
 325                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 326                 attr->u.kprobe.addr = ev->attr.probe.addr;
 327                 attr->u.kprobe.offset = ev->attr.probe.offset;
 328                 strncpy(attr->u.kprobe.symbol_name,
 329                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 330                 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 331                 break;
 332         case LTTNG_EVENT_FUNCTION:
 333                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 334                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 335                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 336                 strncpy(attr->u.kretprobe.symbol_name,
 337                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 338                 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 339                 break;
 340         case LTTNG_EVENT_FUNCTION_ENTRY:
 341                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 342                 strncpy(attr->u.ftrace.symbol_name,
 343                                 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 344                 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 345                 break;
 346         case LTTNG_EVENT_TRACEPOINT:
 347                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 348                 break;
 349         case LTTNG_EVENT_SYSCALL:
 350                 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
 351                 break;
 352         case LTTNG_EVENT_ALL:
 353                 attr->instrumentation = LTTNG_KERNEL_ALL;
 354                 break;
 355         default:
 356                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 357                 goto error;
 358         }
 359
 360         /* Copy event name */
 361         strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
 362         attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 363
 364         /* Setting up a kernel event */
 365         lke->fd = -1;
 366         lke->event = attr;
 367         lke->enabled = 1;
 368         lke->filter_expression = filter_expression;
 369         lke->filter = filter;
 370
 371         return lke;
 372
 373 error:
 374         free(filter_expression);
 375         free(filter);
 376         free(lke);
 377         free(attr);
 378         return NULL;
 379 }
 380
 381 /*
 382  * Allocate and initialize a kernel metadata.
 383  *
 384  * Return pointer to structure or NULL.
 385  */
 386 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 387 {
 388         int ret;
 389         struct ltt_kernel_metadata *lkm;
 390         struct lttng_channel *chan;
 391
 392         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 393         chan = zmalloc(sizeof(struct lttng_channel));
 394         if (lkm == NULL || chan == NULL) {
 395                 PERROR("kernel metadata zmalloc");
 396                 goto error;
 397         }
 398
 399         ret = lttng_strncpy(
 400                         chan->name, DEFAULT_METADATA_NAME, sizeof(chan->name));
 401         if (ret) {
 402                 ERR("Failed to initialize metadata channel name to `%s`",
 403                                 DEFAULT_METADATA_NAME);
 404                 goto error;
 405         }
 406
 407         /* Set default attributes */
 408         chan->attr.overwrite = DEFAULT_METADATA_OVERWRITE;
 409         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 410         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 411         chan->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 412         chan->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;;
 413
 414
 415         /*
 416          * The metadata channel of kernel sessions must use the "mmap"
 417          * back-end since the consumer daemon accumulates complete
 418          * metadata units before sending them to the relay daemon in
 419          * live mode. The consumer daemon also needs to extract the contents
 420          * of the metadata cache when computing a rotation position.
 421          *
 422          * In both cases, it is not possible to rely on the splice
 423          * back-end as the consumer daemon may need to accumulate more
 424          * content than can be backed by the ring buffer's underlying
 425          * pages.
 426          */
 427         chan->attr.output = LTTNG_EVENT_MMAP;
 428         chan->attr.tracefile_size = 0;
 429         chan->attr.tracefile_count = 0;
 430         chan->attr.live_timer_interval = 0;
 431
 432         /* Init metadata */
 433         lkm->fd = -1;
 434         lkm->conf = chan;
 435
 436         return lkm;
 437
 438 error:
 439         free(lkm);
 440         free(chan);
 441         return NULL;
 442 }
 443
 444 /*
 445  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 446  * default.
 447  *
 448  * Return pointer to structure or NULL.
 449  */
 450 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 451                 unsigned int count)
 452 {
 453         int ret;
 454         struct ltt_kernel_stream *lks;
 455
 456         assert(name);
 457
 458         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 459         if (lks == NULL) {
 460                 PERROR("kernel stream zmalloc");
 461                 goto error;
 462         }
 463
 464         /* Set name */
 465         ret = snprintf(lks->name, sizeof(lks->name), "%s_%u", name, count);
 466         if (ret < 0) {
 467                 PERROR("snprintf stream name");
 468                 goto error;
 469         }
 470         lks->name[sizeof(lks->name) - 1] = '\0';
 471
 472         /* Init stream */
 473         lks->fd = -1;
 474         lks->state = 0;
 475         lks->cpu = count;
 476
 477         return lks;
 478
 479 error:
 480         return NULL;
 481 }
 482
 483 /*
 484  * Cleanup kernel stream structure.
 485  */
 486 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 487 {
 488         assert(stream);
 489
 490         DBG("[trace] Closing stream fd %d", stream->fd);
 491         /* Close kernel fd */
 492         if (stream->fd >= 0) {
 493                 int ret;
 494
 495                 ret = close(stream->fd);
 496                 if (ret) {
 497                         PERROR("close");
 498                 }
 499         }
 500         /* Remove from stream list */
 501         cds_list_del(&stream->list);
 502
 503         free(stream);
 504 }
 505
 506 /*
 507  * Cleanup kernel event structure.
 508  */
 509 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 510 {
 511         assert(event);
 512
 513         if (event->fd >= 0) {
 514                 int ret;
 515
 516                 DBG("[trace] Closing event fd %d", event->fd);
 517                 /* Close kernel fd */
 518                 ret = close(event->fd);
 519                 if (ret) {
 520                         PERROR("close");
 521                 }
 522         } else {
 523                 DBG("[trace] Tearing down event (no associated fd)");
 524         }
 525
 526         /* Remove from event list */
 527         cds_list_del(&event->list);
 528
 529         free(event->filter_expression);
 530         free(event->filter);
 531
 532         free(event->event);
 533         free(event);
 534 }
 535
 536 /*
 537  * Cleanup kernel context structure.
 538  */
 539 void trace_kernel_destroy_context(struct ltt_kernel_context *ctx)
 540 {
 541         assert(ctx);
 542
 543         if (ctx->in_list) {
 544                 cds_list_del(&ctx->list);
 545         }
 546         free(ctx);
 547 }
 548
 549 /*
 550  * Cleanup kernel channel structure.
 551  */
 552 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 553 {
 554         struct ltt_kernel_stream *stream, *stmp;
 555         struct ltt_kernel_event *event, *etmp;
 556         struct ltt_kernel_context *ctx, *ctmp;
 557         int ret;
 558
 559         assert(channel);
 560
 561         DBG("[trace] Closing channel fd %d", channel->fd);
 562         /* Close kernel fd */
 563         if (channel->fd >= 0) {
 564                 ret = close(channel->fd);
 565                 if (ret) {
 566                         PERROR("close");
 567                 }
 568         }
 569
 570         /* For each stream in the channel list */
 571         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 572                 trace_kernel_destroy_stream(stream);
 573         }
 574
 575         /* For each event in the channel list */
 576         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 577                 trace_kernel_destroy_event(event);
 578         }
 579
 580         /* For each context in the channel list */
 581         cds_list_for_each_entry_safe(ctx, ctmp, &channel->ctx_list, list) {
 582                 trace_kernel_destroy_context(ctx);
 583         }
 584
 585         /* Remove from channel list */
 586         cds_list_del(&channel->list);
 587
 588         free(channel->channel);
 589         free(channel);
 590 }
 591
 592 /*
 593  * Cleanup kernel metadata structure.
 594  */
 595 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 596 {
 597         assert(metadata);
 598
 599         DBG("[trace] Closing metadata fd %d", metadata->fd);
 600         /* Close kernel fd */
 601         if (metadata->fd >= 0) {
 602                 int ret;
 603
 604                 ret = close(metadata->fd);
 605                 if (ret) {
 606                         PERROR("close");
 607                 }
 608         }
 609
 610         free(metadata->conf);
 611         free(metadata);
 612 }
 613
 614 /*
 615  * Cleanup kernel session structure
 616  *
 617  * Should *NOT* be called with RCU read-side lock held.
 618  */
 619 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 620 {
 621         struct ltt_kernel_channel *channel, *ctmp;
 622         int ret;
 623
 624         assert(session);
 625
 626         DBG("[trace] Closing session fd %d", session->fd);
 627         /* Close kernel fds */
 628         if (session->fd >= 0) {
 629                 ret = close(session->fd);
 630                 if (ret) {
 631                         PERROR("close");
 632                 }
 633         }
 634
 635         if (session->metadata_stream_fd >= 0) {
 636                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 637                 ret = close(session->metadata_stream_fd);
 638                 if (ret) {
 639                         PERROR("close");
 640                 }
 641         }
 642
 643         if (session->metadata != NULL) {
 644                 trace_kernel_destroy_metadata(session->metadata);
 645         }
 646
 647         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 648                 trace_kernel_destroy_channel(channel);
 649         }
 650
 651         /* Wipe consumer output object */
 652         consumer_output_put(session->consumer);
 653
 654         lttng_tracker_list_destroy(session->tracker_list_pid);
 655         lttng_tracker_list_destroy(session->tracker_list_vpid);
 656         lttng_tracker_list_destroy(session->tracker_list_uid);
 657         lttng_tracker_list_destroy(session->tracker_list_vuid);
 658         lttng_tracker_list_destroy(session->tracker_list_gid);
 659         lttng_tracker_list_destroy(session->tracker_list_vgid);
 660
 661         free(session);
 662 }