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

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _LGPL_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <inttypes.h>
  25
  26 #include <common/common.h>
  27 #include <common/defaults.h>
  28 #include <common/trace-chunk.h>
  29
  30 #include "buffer-registry.h"
  31 #include "trace-ust.h"
  32 #include "utils.h"
  33 #include "ust-app.h"
  34 #include "agent.h"
  35
  36 /*
  37  * Match function for the events hash table lookup.
  38  *
  39  * Matches by name only. Used by the disable command.
  40  */
  41 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  42                 const void *_key)
  43 {
  44         struct ltt_ust_event *event;
  45         const char *name;
  46
  47         assert(node);
  48         assert(_key);
  49
  50         event = caa_container_of(node, struct ltt_ust_event, node.node);
  51         name = _key;
  52
  53         /* Event name */
  54         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  55                 goto no_match;
  56         }
  57
  58         /* Match */
  59         return 1;
  60
  61 no_match:
  62         return 0;
  63 }
  64
  65 /*
  66  * Match function for the hash table lookup.
  67  *
  68  * It matches an ust event based on three attributes which are the event name,
  69  * the filter bytecode and the loglevel.
  70  */
  71 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  72 {
  73         struct ltt_ust_event *event;
  74         const struct ltt_ust_ht_key *key;
  75         int ev_loglevel_value;
  76         int ll_match;
  77
  78         assert(node);
  79         assert(_key);
  80
  81         event = caa_container_of(node, struct ltt_ust_event, node.node);
  82         key = _key;
  83         ev_loglevel_value = event->attr.loglevel;
  84
  85         /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
  86
  87         /* Event name */
  88         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  89                 goto no_match;
  90         }
  91
  92         /* Event loglevel value and type. */
  93         ll_match = loglevels_match(event->attr.loglevel_type,
  94                 ev_loglevel_value, key->loglevel_type,
  95                 key->loglevel_value, LTTNG_UST_LOGLEVEL_ALL);
  96
  97         if (!ll_match) {
  98                 goto no_match;
  99         }
 100
 101         /* Only one of the filters is NULL, fail. */
 102         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 103                 goto no_match;
 104         }
 105
 106         if (key->filter && event->filter) {
 107                 /* Both filters exists, check length followed by the bytecode. */
 108                 if (event->filter->len != key->filter->len ||
 109                                 memcmp(event->filter->data, key->filter->data,
 110                                         event->filter->len) != 0) {
 111                         goto no_match;
 112                 }
 113         }
 114
 115         /* If only one of the exclusions is NULL, fail. */
 116         if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
 117                 goto no_match;
 118         }
 119
 120         if (key->exclusion && event->exclusion) {
 121                 size_t i;
 122
 123                 /* Check exclusion counts first. */
 124                 if (event->exclusion->count != key->exclusion->count) {
 125                         goto no_match;
 126                 }
 127
 128                 /* Compare names individually. */
 129                 for (i = 0; i < event->exclusion->count; ++i) {
 130                         size_t j;
 131                         bool found = false;
 132                         const char *name_ev =
 133                                 LTTNG_EVENT_EXCLUSION_NAME_AT(
 134                                         event->exclusion, i);
 135
 136                         /*
 137                          * Compare this exclusion name to all the key's
 138                          * exclusion names.
 139                          */
 140                         for (j = 0; j < key->exclusion->count; ++j) {
 141                                 const char *name_key =
 142                                         LTTNG_EVENT_EXCLUSION_NAME_AT(
 143                                                 key->exclusion, j);
 144
 145                                 if (!strncmp(name_ev, name_key,
 146                                                 LTTNG_SYMBOL_NAME_LEN)) {
 147                                         /* Names match! */
 148                                         found = true;
 149                                         break;
 150                                 }
 151                         }
 152
 153                         /*
 154                          * If the current exclusion name was not found amongst
 155                          * the key's exclusion names, then there's no match.
 156                          */
 157                         if (!found) {
 158                                 goto no_match;
 159                         }
 160                 }
 161         }
 162         /* Match. */
 163         return 1;
 164
 165 no_match:
 166         return 0;
 167 }
 168
 169 /*
 170  * Find the channel in the hashtable and return channel pointer. RCU read side
 171  * lock MUST be acquired before calling this.
 172  */
 173 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 174                 const char *name)
 175 {
 176         struct lttng_ht_node_str *node;
 177         struct lttng_ht_iter iter;
 178
 179         /*
 180          * If we receive an empty string for channel name, it means the
 181          * default channel name is requested.
 182          */
 183         if (name[0] == '\0')
 184                 name = DEFAULT_CHANNEL_NAME;
 185
 186         lttng_ht_lookup(ht, (void *)name, &iter);
 187         node = lttng_ht_iter_get_node_str(&iter);
 188         if (node == NULL) {
 189                 goto error;
 190         }
 191
 192         DBG2("Trace UST channel %s found by name", name);
 193
 194         return caa_container_of(node, struct ltt_ust_channel, node);
 195
 196 error:
 197         DBG2("Trace UST channel %s not found by name", name);
 198         return NULL;
 199 }
 200
 201 /*
 202  * Find the event in the hashtable and return event pointer. RCU read side lock
 203  * MUST be acquired before calling this.
 204  */
 205 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 206                 char *name, struct lttng_filter_bytecode *filter,
 207                 enum lttng_ust_loglevel_type loglevel_type, int loglevel_value,
 208                 struct lttng_event_exclusion *exclusion)
 209 {
 210         struct lttng_ht_node_str *node;
 211         struct lttng_ht_iter iter;
 212         struct ltt_ust_ht_key key;
 213
 214         assert(name);
 215         assert(ht);
 216
 217         key.name = name;
 218         key.filter = filter;
 219         key.loglevel_type = loglevel_type;
 220         key.loglevel_value = loglevel_value;
 221         key.exclusion = exclusion;
 222
 223         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 224                         trace_ust_ht_match_event, &key, &iter.iter);
 225         node = lttng_ht_iter_get_node_str(&iter);
 226         if (node == NULL) {
 227                 goto error;
 228         }
 229
 230         DBG2("Trace UST event %s found", key.name);
 231
 232         return caa_container_of(node, struct ltt_ust_event, node);
 233
 234 error:
 235         DBG2("Trace UST event %s NOT found", key.name);
 236         return NULL;
 237 }
 238
 239 /*
 240  * Lookup an agent in the session agents hash table by domain type and return
 241  * the object if found else NULL.
 242  *
 243  * RCU read side lock must be acquired before calling and only released
 244  * once the agent is no longer in scope or being used.
 245  */
 246 struct agent *trace_ust_find_agent(struct ltt_ust_session *session,
 247                 enum lttng_domain_type domain_type)
 248 {
 249         struct agent *agt = NULL;
 250         struct lttng_ht_node_u64 *node;
 251         struct lttng_ht_iter iter;
 252         uint64_t key;
 253
 254         assert(session);
 255
 256         DBG3("Trace ust agent lookup for domain %d", domain_type);
 257
 258         key = domain_type;
 259
 260         lttng_ht_lookup(session->agents, &key, &iter);
 261         node = lttng_ht_iter_get_node_u64(&iter);
 262         if (!node) {
 263                 goto end;
 264         }
 265         agt = caa_container_of(node, struct agent, node);
 266
 267 end:
 268         return agt;
 269 }
 270
 271 /*
 272  * Allocate and initialize a ust session data structure.
 273  *
 274  * Return pointer to structure or NULL.
 275  */
 276 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 277 {
 278         struct ltt_ust_session *lus;
 279
 280         /* Allocate a new ltt ust session */
 281         lus = zmalloc(sizeof(struct ltt_ust_session));
 282         if (lus == NULL) {
 283                 PERROR("create ust session zmalloc");
 284                 goto error_alloc;
 285         }
 286
 287         /* Init data structure */
 288         lus->id = session_id;
 289         lus->active = 0;
 290
 291         /* Set default metadata channel attribute. */
 292         lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 293         lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
 294         lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 295         lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 296         lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 297         lus->metadata_attr.output = LTTNG_UST_MMAP;
 298
 299         /*
 300          * Default buffer type. This can be changed through an enable channel
 301          * requesting a different type. Note that this can only be changed once
 302          * during the session lifetime which is at the first enable channel and
 303          * only before start. The flag buffer_type_changed indicates the status.
 304          */
 305         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 306         /* Once set to 1, the buffer_type is immutable for the session. */
 307         lus->buffer_type_changed = 0;
 308         /* Init it in case it get used after allocation. */
 309         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 310
 311         /* Alloc UST global domain channels' HT */
 312         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 313         /* Alloc agent hash table. */
 314         lus->agents = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 315
 316         lus->tracker_list_vpid = lttng_tracker_list_create();
 317         if (!lus->tracker_list_vpid) {
 318                 goto error;
 319         }
 320         lus->tracker_list_vuid = lttng_tracker_list_create();
 321         if (!lus->tracker_list_vuid) {
 322                 goto error;
 323         }
 324         lus->tracker_list_vgid = lttng_tracker_list_create();
 325         if (!lus->tracker_list_vgid) {
 326                 goto error;
 327         }
 328         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 329         if (lus->consumer == NULL) {
 330                 goto error;
 331         }
 332
 333         DBG2("UST trace session create successful");
 334
 335         return lus;
 336
 337 error:
 338         lttng_tracker_list_destroy(lus->tracker_list_vpid);
 339         lttng_tracker_list_destroy(lus->tracker_list_vuid);
 340         lttng_tracker_list_destroy(lus->tracker_list_vgid);
 341         ht_cleanup_push(lus->domain_global.channels);
 342         ht_cleanup_push(lus->agents);
 343         free(lus);
 344 error_alloc:
 345         return NULL;
 346 }
 347
 348 /*
 349  * Allocate and initialize a ust channel data structure.
 350  *
 351  * Return pointer to structure or NULL.
 352  */
 353 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 354                 enum lttng_domain_type domain)
 355 {
 356         struct ltt_ust_channel *luc;
 357
 358         assert(chan);
 359
 360         luc = zmalloc(sizeof(struct ltt_ust_channel));
 361         if (luc == NULL) {
 362                 PERROR("ltt_ust_channel zmalloc");
 363                 goto error;
 364         }
 365
 366         luc->domain = domain;
 367
 368         /* Copy UST channel attributes */
 369         luc->attr.overwrite = chan->attr.overwrite;
 370         luc->attr.subbuf_size = chan->attr.subbuf_size;
 371         luc->attr.num_subbuf = chan->attr.num_subbuf;
 372         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 373         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 374         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 375         luc->monitor_timer_interval = ((struct lttng_channel_extended *)
 376                         chan->attr.extended.ptr)->monitor_timer_interval;
 377         luc->attr.u.s.blocking_timeout = ((struct lttng_channel_extended *)
 378                         chan->attr.extended.ptr)->blocking_timeout;
 379
 380         /* Translate to UST output enum */
 381         switch (luc->attr.output) {
 382         default:
 383                 luc->attr.output = LTTNG_UST_MMAP;
 384                 break;
 385         }
 386
 387         /*
 388          * If we receive an empty string for channel name, it means the
 389          * default channel name is requested.
 390          */
 391         if (chan->name[0] == '\0') {
 392                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 393         } else {
 394                 /* Copy channel name */
 395                 strncpy(luc->name, chan->name, sizeof(luc->name));
 396         }
 397         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 398
 399         /* Init node */
 400         lttng_ht_node_init_str(&luc->node, luc->name);
 401         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 402
 403         /* Alloc hash tables */
 404         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 405         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 406
 407         /* On-disk circular buffer parameters */
 408         luc->tracefile_size = chan->attr.tracefile_size;
 409         luc->tracefile_count = chan->attr.tracefile_count;
 410
 411         DBG2("Trace UST channel %s created", luc->name);
 412
 413 error:
 414         return luc;
 415 }
 416
 417 /*
 418  * Validates an exclusion list.
 419  *
 420  * Returns 0 if valid, negative value if invalid.
 421  */
 422 static int validate_exclusion(struct lttng_event_exclusion *exclusion)
 423 {
 424         size_t i;
 425         int ret = 0;
 426
 427         assert(exclusion);
 428
 429         for (i = 0; i < exclusion->count; ++i) {
 430                 size_t j;
 431                 const char *name_a =
 432                         LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
 433
 434                 for (j = 0; j < i; ++j) {
 435                         const char *name_b =
 436                                 LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, j);
 437
 438                         if (!strncmp(name_a, name_b, LTTNG_SYMBOL_NAME_LEN)) {
 439                                 /* Match! */
 440                                 ret = -1;
 441                                 goto end;
 442                         }
 443                 }
 444         }
 445
 446 end:
 447         return ret;
 448 }
 449
 450 /*
 451  * Allocate and initialize a ust event. Set name and event type.
 452  * We own filter_expression, filter, and exclusion.
 453  *
 454  * Return an lttng_error_code
 455  */
 456 enum lttng_error_code trace_ust_create_event(struct lttng_event *ev,
 457                 char *filter_expression,
 458                 struct lttng_filter_bytecode *filter,
 459                 struct lttng_event_exclusion *exclusion,
 460                 bool internal_event,
 461                 struct ltt_ust_event **ust_event)
 462 {
 463         struct ltt_ust_event *local_ust_event;
 464         enum lttng_error_code ret = LTTNG_OK;
 465
 466         assert(ev);
 467
 468         if (exclusion && validate_exclusion(exclusion)) {
 469                 ret = LTTNG_ERR_INVALID;
 470                 goto error;
 471         }
 472
 473         local_ust_event = zmalloc(sizeof(struct ltt_ust_event));
 474         if (local_ust_event == NULL) {
 475                 PERROR("ust event zmalloc");
 476                 ret = LTTNG_ERR_NOMEM;
 477                 goto error;
 478         }
 479
 480         local_ust_event->internal = internal_event;
 481
 482         switch (ev->type) {
 483         case LTTNG_EVENT_PROBE:
 484                 local_ust_event->attr.instrumentation = LTTNG_UST_PROBE;
 485                 break;
 486         case LTTNG_EVENT_FUNCTION:
 487                 local_ust_event->attr.instrumentation = LTTNG_UST_FUNCTION;
 488                 break;
 489         case LTTNG_EVENT_FUNCTION_ENTRY:
 490                 local_ust_event->attr.instrumentation = LTTNG_UST_FUNCTION;
 491                 break;
 492         case LTTNG_EVENT_TRACEPOINT:
 493                 local_ust_event->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 494                 break;
 495         default:
 496                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 497                 ret = LTTNG_ERR_INVALID;
 498                 goto error_free_event;
 499         }
 500
 501         /* Copy event name */
 502         strncpy(local_ust_event->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 503         local_ust_event->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 504
 505         switch (ev->loglevel_type) {
 506         case LTTNG_EVENT_LOGLEVEL_ALL:
 507                 local_ust_event->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 508                 local_ust_event->attr.loglevel = -1;    /* Force to -1 */
 509                 break;
 510         case LTTNG_EVENT_LOGLEVEL_RANGE:
 511                 local_ust_event->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 512                 local_ust_event->attr.loglevel = ev->loglevel;
 513                 break;
 514         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 515                 local_ust_event->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 516                 local_ust_event->attr.loglevel = ev->loglevel;
 517                 break;
 518         default:
 519                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 520                 ret = LTTNG_ERR_INVALID;
 521                 goto error_free_event;
 522         }
 523
 524         /* Same layout. */
 525         local_ust_event->filter_expression = filter_expression;
 526         local_ust_event->filter = filter;
 527         local_ust_event->exclusion = exclusion;
 528
 529         /* Init node */
 530         lttng_ht_node_init_str(&local_ust_event->node, local_ust_event->attr.name);
 531
 532         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 533                 local_ust_event->attr.name, local_ust_event->attr.loglevel_type,
 534                 local_ust_event->attr.loglevel);
 535
 536         *ust_event = local_ust_event;
 537
 538         return ret;
 539
 540 error_free_event:
 541         free(local_ust_event);
 542 error:
 543         free(filter_expression);
 544         free(filter);
 545         free(exclusion);
 546         return ret;
 547 }
 548
 549 static
 550 int trace_ust_context_type_event_to_ust(
 551                 enum lttng_event_context_type type)
 552 {
 553         int utype;
 554
 555         switch (type) {
 556         case LTTNG_EVENT_CONTEXT_VTID:
 557                 utype = LTTNG_UST_CONTEXT_VTID;
 558                 break;
 559         case LTTNG_EVENT_CONTEXT_VPID:
 560                 utype = LTTNG_UST_CONTEXT_VPID;
 561                 break;
 562         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 563                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 564                 break;
 565         case LTTNG_EVENT_CONTEXT_PROCNAME:
 566                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 567                 break;
 568         case LTTNG_EVENT_CONTEXT_IP:
 569                 utype = LTTNG_UST_CONTEXT_IP;
 570                 break;
 571         case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
 572                 if (!ustctl_has_perf_counters()) {
 573                         utype = -1;
 574                         WARN("Perf counters not implemented in UST");
 575                 } else {
 576                         utype = LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER;
 577                 }
 578                 break;
 579         case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
 580                 utype = LTTNG_UST_CONTEXT_APP_CONTEXT;
 581                 break;
 582         case LTTNG_EVENT_CONTEXT_CGROUP_NS:
 583                 utype = LTTNG_UST_CONTEXT_CGROUP_NS;
 584                 break;
 585         case LTTNG_EVENT_CONTEXT_IPC_NS:
 586                 utype = LTTNG_UST_CONTEXT_IPC_NS;
 587                 break;
 588         case LTTNG_EVENT_CONTEXT_MNT_NS:
 589                 utype = LTTNG_UST_CONTEXT_MNT_NS;
 590                 break;
 591         case LTTNG_EVENT_CONTEXT_NET_NS:
 592                 utype = LTTNG_UST_CONTEXT_NET_NS;
 593                 break;
 594         case LTTNG_EVENT_CONTEXT_PID_NS:
 595                 utype = LTTNG_UST_CONTEXT_PID_NS;
 596                 break;
 597         case LTTNG_EVENT_CONTEXT_USER_NS:
 598                 utype = LTTNG_UST_CONTEXT_USER_NS;
 599                 break;
 600         case LTTNG_EVENT_CONTEXT_UTS_NS:
 601                 utype = LTTNG_UST_CONTEXT_UTS_NS;
 602                 break;
 603         case LTTNG_EVENT_CONTEXT_VUID:
 604                 utype = LTTNG_UST_CONTEXT_VUID;
 605                 break;
 606         case LTTNG_EVENT_CONTEXT_VEUID:
 607                 utype = LTTNG_UST_CONTEXT_VEUID;
 608                 break;
 609         case LTTNG_EVENT_CONTEXT_VSUID:
 610                 utype = LTTNG_UST_CONTEXT_VSUID;
 611                 break;
 612         case LTTNG_EVENT_CONTEXT_VGID:
 613                 utype = LTTNG_UST_CONTEXT_VGID;
 614                 break;
 615         case LTTNG_EVENT_CONTEXT_VEGID:
 616                 utype = LTTNG_UST_CONTEXT_VEGID;
 617                 break;
 618         case LTTNG_EVENT_CONTEXT_VSGID:
 619                 utype = LTTNG_UST_CONTEXT_VSGID;
 620                 break;
 621         default:
 622                 utype = -1;
 623                 break;
 624         }
 625         return utype;
 626 }
 627
 628 /*
 629  * Return 1 if contexts match, 0 otherwise.
 630  */
 631 int trace_ust_match_context(const struct ltt_ust_context *uctx,
 632                 const struct lttng_event_context *ctx)
 633 {
 634         int utype;
 635
 636         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 637         if (utype < 0) {
 638                 return 0;
 639         }
 640         if (uctx->ctx.ctx != utype) {
 641                 return 0;
 642         }
 643         switch (utype) {
 644         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 645                 if (uctx->ctx.u.perf_counter.type
 646                                 != ctx->u.perf_counter.type) {
 647                         return 0;
 648                 }
 649                 if (uctx->ctx.u.perf_counter.config
 650                                 != ctx->u.perf_counter.config) {
 651                         return 0;
 652                 }
 653                 if (strncmp(uctx->ctx.u.perf_counter.name,
 654                                 ctx->u.perf_counter.name,
 655                                 LTTNG_UST_SYM_NAME_LEN)) {
 656                         return 0;
 657                 }
 658                 break;
 659         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 660                 assert(uctx->ctx.u.app_ctx.provider_name);
 661                 assert(uctx->ctx.u.app_ctx.ctx_name);
 662                 if (strcmp(uctx->ctx.u.app_ctx.provider_name,
 663                                 ctx->u.app_ctx.provider_name) ||
 664                                 strcmp(uctx->ctx.u.app_ctx.ctx_name,
 665                                 ctx->u.app_ctx.ctx_name)) {
 666                         return 0;
 667                 }
 668         default:
 669                 break;
 670
 671         }
 672         return 1;
 673 }
 674
 675 /*
 676  * Allocate and initialize an UST context.
 677  *
 678  * Return pointer to structure or NULL.
 679  */
 680 struct ltt_ust_context *trace_ust_create_context(
 681                 const struct lttng_event_context *ctx)
 682 {
 683         struct ltt_ust_context *uctx = NULL;
 684         int utype;
 685
 686         assert(ctx);
 687
 688         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 689         if (utype < 0) {
 690                 ERR("Invalid UST context");
 691                 goto end;
 692         }
 693
 694         uctx = zmalloc(sizeof(struct ltt_ust_context));
 695         if (!uctx) {
 696                 PERROR("zmalloc ltt_ust_context");
 697                 goto end;
 698         }
 699
 700         uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
 701         switch (utype) {
 702         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 703                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 704                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 705                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 706                                 LTTNG_UST_SYM_NAME_LEN);
 707                 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 708                 break;
 709         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 710         {
 711                 char *provider_name = NULL, *ctx_name = NULL;
 712
 713                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 714                 if (!provider_name) {
 715                         goto error;
 716                 }
 717                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 718
 719                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 720                 if (!ctx_name) {
 721                         goto error;
 722                 }
 723                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 724                 break;
 725         }
 726         default:
 727                 break;
 728         }
 729         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 730 end:
 731         return uctx;
 732 error:
 733         trace_ust_destroy_context(uctx);
 734         return NULL;
 735 }
 736
 737 static void destroy_id_tracker_node_rcu(struct rcu_head *head)
 738 {
 739         struct ust_id_tracker_node *tracker_node = caa_container_of(
 740                         head, struct ust_id_tracker_node, node.head);
 741         free(tracker_node);
 742 }
 743
 744 static void destroy_id_tracker_node(struct ust_id_tracker_node *tracker_node)
 745 {
 746         call_rcu(&tracker_node->node.head, destroy_id_tracker_node_rcu);
 747 }
 748
 749 static int init_id_tracker(struct ust_id_tracker *id_tracker)
 750 {
 751         int ret = LTTNG_OK;
 752
 753         id_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 754         if (!id_tracker->ht) {
 755                 ret = LTTNG_ERR_NOMEM;
 756                 goto end;
 757         }
 758
 759 end:
 760         return ret;
 761 }
 762
 763 /*
 764  * Teardown id tracker content, but don't free id_tracker object.
 765  */
 766 static void fini_id_tracker(struct ust_id_tracker *id_tracker)
 767 {
 768         struct ust_id_tracker_node *tracker_node;
 769         struct lttng_ht_iter iter;
 770
 771         if (!id_tracker->ht) {
 772                 return;
 773         }
 774         rcu_read_lock();
 775         cds_lfht_for_each_entry (id_tracker->ht->ht, &iter.iter, tracker_node,
 776                         node.node) {
 777                 int ret = lttng_ht_del(id_tracker->ht, &iter);
 778
 779                 assert(!ret);
 780                 destroy_id_tracker_node(tracker_node);
 781         }
 782         rcu_read_unlock();
 783         ht_cleanup_push(id_tracker->ht);
 784         id_tracker->ht = NULL;
 785 }
 786
 787 static struct ust_id_tracker_node *id_tracker_lookup(
 788                 struct ust_id_tracker *id_tracker,
 789                 int id,
 790                 struct lttng_ht_iter *iter)
 791 {
 792         unsigned long _id = (unsigned long) id;
 793         struct lttng_ht_node_ulong *node;
 794
 795         lttng_ht_lookup(id_tracker->ht, (void *) _id, iter);
 796         node = lttng_ht_iter_get_node_ulong(iter);
 797         if (node) {
 798                 return caa_container_of(node, struct ust_id_tracker_node, node);
 799         } else {
 800                 return NULL;
 801         }
 802 }
 803
 804 static int id_tracker_add_id(struct ust_id_tracker *id_tracker, int id)
 805 {
 806         int retval = LTTNG_OK;
 807         struct ust_id_tracker_node *tracker_node;
 808         struct lttng_ht_iter iter;
 809
 810         if (id < 0) {
 811                 retval = LTTNG_ERR_INVALID;
 812                 goto end;
 813         }
 814         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 815         if (tracker_node) {
 816                 /* Already exists. */
 817                 retval = LTTNG_ERR_ID_TRACKED;
 818                 goto end;
 819         }
 820         tracker_node = zmalloc(sizeof(*tracker_node));
 821         if (!tracker_node) {
 822                 retval = LTTNG_ERR_NOMEM;
 823                 goto end;
 824         }
 825         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) id);
 826         lttng_ht_add_unique_ulong(id_tracker->ht, &tracker_node->node);
 827 end:
 828         return retval;
 829 }
 830
 831 static int id_tracker_del_id(struct ust_id_tracker *id_tracker, int id)
 832 {
 833         int retval = LTTNG_OK, ret;
 834         struct ust_id_tracker_node *tracker_node;
 835         struct lttng_ht_iter iter;
 836
 837         if (id < 0) {
 838                 retval = LTTNG_ERR_INVALID;
 839                 goto end;
 840         }
 841         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 842         if (!tracker_node) {
 843                 /* Not found */
 844                 retval = LTTNG_ERR_ID_NOT_TRACKED;
 845                 goto end;
 846         }
 847         ret = lttng_ht_del(id_tracker->ht, &iter);
 848         assert(!ret);
 849
 850         destroy_id_tracker_node(tracker_node);
 851 end:
 852         return retval;
 853 }
 854
 855 static struct ust_id_tracker *get_id_tracker(struct ltt_ust_session *session,
 856                 enum lttng_tracker_type tracker_type)
 857 {
 858         switch (tracker_type) {
 859         case LTTNG_TRACKER_VPID:
 860                 return &session->vpid_tracker;
 861         case LTTNG_TRACKER_VUID:
 862                 return &session->vuid_tracker;
 863         case LTTNG_TRACKER_VGID:
 864                 return &session->vgid_tracker;
 865         default:
 866                 return NULL;
 867         }
 868 }
 869
 870 static struct lttng_tracker_list *get_id_tracker_list(
 871                 struct ltt_ust_session *session,
 872                 enum lttng_tracker_type tracker_type)
 873 {
 874         switch (tracker_type) {
 875         case LTTNG_TRACKER_VPID:
 876                 return session->tracker_list_vpid;
 877         case LTTNG_TRACKER_VUID:
 878                 return session->tracker_list_vuid;
 879         case LTTNG_TRACKER_VGID:
 880                 return session->tracker_list_vgid;
 881         default:
 882                 return NULL;
 883         }
 884 }
 885
 886 /*
 887  * The session lock is held when calling this function.
 888  */
 889 int trace_ust_id_tracker_lookup(enum lttng_tracker_type tracker_type,
 890                 struct ltt_ust_session *session,
 891                 int id)
 892 {
 893         struct lttng_ht_iter iter;
 894         struct ust_id_tracker *id_tracker;
 895
 896         id_tracker = get_id_tracker(session, tracker_type);
 897         if (!id_tracker) {
 898                 abort();
 899         }
 900         if (!id_tracker->ht) {
 901                 return 1;
 902         }
 903         if (id_tracker_lookup(id_tracker, id, &iter)) {
 904                 return 1;
 905         }
 906         return 0;
 907 }
 908
 909 /*
 910  * Called with the session lock held.
 911  */
 912 int trace_ust_track_id(enum lttng_tracker_type tracker_type,
 913                 struct ltt_ust_session *session,
 914                 const struct lttng_tracker_id *id)
 915 {
 916         int retval = LTTNG_OK;
 917         bool should_update_apps = false;
 918         struct ust_id_tracker *id_tracker;
 919         struct lttng_tracker_list *tracker_list;
 920         int value;
 921         struct lttng_tracker_id **saved_ids;
 922         ssize_t saved_ids_count;
 923
 924         if (tracker_type == LTTNG_TRACKER_PID) {
 925                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
 926                 tracker_type = LTTNG_TRACKER_VPID;
 927         }
 928
 929         retval = lttng_tracker_id_lookup_string(tracker_type, id, &value);
 930         if (retval != LTTNG_OK) {
 931                 return retval;
 932         }
 933         tracker_list = get_id_tracker_list(session, tracker_type);
 934         if (!tracker_list) {
 935                 return LTTNG_ERR_INVALID;
 936         }
 937         /* Save list for restore on error. */
 938         saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
 939         if (saved_ids_count < 0) {
 940                 return LTTNG_ERR_INVALID;
 941         }
 942         /* Add to list. */
 943         retval = lttng_tracker_list_add(tracker_list, id);
 944         if (retval != LTTNG_OK) {
 945                 goto end;
 946         }
 947
 948         id_tracker = get_id_tracker(session, tracker_type);
 949         if (!id_tracker) {
 950                 abort();
 951         }
 952         if (value == -1) {
 953                 /* Track all ids: destroy tracker if exists. */
 954                 if (id_tracker->ht) {
 955                         fini_id_tracker(id_tracker);
 956                         /* Ensure all apps have session. */
 957                         should_update_apps = true;
 958                 }
 959         } else {
 960                 if (!id_tracker->ht) {
 961                         /* Create tracker. */
 962                         retval = init_id_tracker(id_tracker);
 963                         if (retval != LTTNG_OK) {
 964                                 ERR("Error initializing ID tracker");
 965                                 goto end_restore;
 966                         }
 967                         retval = id_tracker_add_id(id_tracker, value);
 968                         if (retval != LTTNG_OK) {
 969                                 fini_id_tracker(id_tracker);
 970                                 goto end_restore;
 971                         }
 972                         /* Remove all apps from session except pid. */
 973                         should_update_apps = true;
 974                 } else {
 975                         struct ust_app *app;
 976
 977                         retval = id_tracker_add_id(id_tracker, value);
 978                         if (retval != LTTNG_OK) {
 979                                 goto end_restore;
 980                         }
 981                         /* Add session to application */
 982                         switch (tracker_type) {
 983                         case LTTNG_TRACKER_VPID:
 984                                 app = ust_app_find_by_pid(value);
 985                                 if (app) {
 986                                         should_update_apps = true;
 987                                 }
 988                                 break;
 989                         default:
 990                                 should_update_apps = true;
 991                         }
 992                 }
 993         }
 994         if (should_update_apps && session->active) {
 995                 ust_app_global_update_all(session);
 996         }
 997         goto end;
 998
 999 end_restore:
1000         if (lttng_tracker_id_set_list(tracker_list, saved_ids,
1001                             saved_ids_count) != LTTNG_OK) {
1002                 ERR("Error on tracker add error handling.\n");
1003         }
1004 end:
1005         lttng_tracker_ids_destroy(saved_ids, saved_ids_count);
1006         free(saved_ids);
1007         return retval;
1008 }
1009
1010 /*
1011  * Called with the session lock held.
1012  */
1013 int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
1014                 struct ltt_ust_session *session,
1015                 const struct lttng_tracker_id *id)
1016 {
1017         int retval = LTTNG_OK;
1018         bool should_update_apps = false;
1019         struct ust_id_tracker *id_tracker;
1020         struct lttng_tracker_list *tracker_list;
1021         int value;
1022         struct lttng_tracker_id **saved_ids;
1023         ssize_t saved_ids_count;
1024
1025         if (tracker_type == LTTNG_TRACKER_PID) {
1026                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
1027                 tracker_type = LTTNG_TRACKER_VPID;
1028         }
1029
1030         retval = lttng_tracker_id_lookup_string(tracker_type, id, &value);
1031         if (retval != LTTNG_OK) {
1032                 return retval;
1033         }
1034
1035         tracker_list = get_id_tracker_list(session, tracker_type);
1036         if (!tracker_list) {
1037                 return LTTNG_ERR_INVALID;
1038         }
1039         /* Save list for restore on error. */
1040         saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
1041         if (saved_ids_count < 0) {
1042                 return LTTNG_ERR_INVALID;
1043         }
1044         /* Remove from list. */
1045         retval = lttng_tracker_list_remove(tracker_list, id);
1046         if (retval != LTTNG_OK) {
1047                 goto end;
1048         }
1049
1050         id_tracker = get_id_tracker(session, tracker_type);
1051         if (!id_tracker) {
1052                 abort();
1053         }
1054
1055         if (value == -1) {
1056                 /* Create empty tracker, replace old tracker. */
1057                 struct ust_id_tracker tmp_tracker;
1058
1059                 tmp_tracker = *id_tracker;
1060                 retval = init_id_tracker(id_tracker);
1061                 if (retval != LTTNG_OK) {
1062                         ERR("Error initializing ID tracker");
1063                         /* Rollback operation. */
1064                         *id_tracker = tmp_tracker;
1065                         goto end_restore;
1066                 }
1067                 fini_id_tracker(&tmp_tracker);
1068
1069                 /* Remove session from all applications */
1070                 should_update_apps = true;
1071         } else {
1072                 struct ust_app *app;
1073
1074                 if (!id_tracker->ht) {
1075                         /* No ID being tracked. */
1076                         retval = LTTNG_ERR_ID_NOT_TRACKED;
1077                         goto end_restore;
1078                 }
1079                 /* Remove ID from tracker */
1080                 retval = id_tracker_del_id(id_tracker, value);
1081                 if (retval != LTTNG_OK) {
1082                         goto end_restore;
1083                 }
1084                 switch (tracker_type) {
1085                 case LTTNG_TRACKER_VPID:
1086                         /* Remove session from application. */
1087                         app = ust_app_find_by_pid(value);
1088                         if (app) {
1089                                 should_update_apps = true;
1090                         }
1091                         break;
1092                 default:
1093                         /* Keep only apps matching ID. */
1094                         should_update_apps = true;
1095                 }
1096         }
1097         if (should_update_apps && session->active) {
1098                 ust_app_global_update_all(session);
1099         }
1100         goto end;
1101
1102 end_restore:
1103         if (lttng_tracker_id_set_list(tracker_list, saved_ids,
1104                             saved_ids_count) != LTTNG_OK) {
1105                 ERR("Error on tracker remove error handling.\n");
1106         }
1107 end:
1108         lttng_tracker_ids_destroy(saved_ids, saved_ids_count);
1109         free(saved_ids);
1110         return retval;
1111 }
1112
1113 /*
1114  * Called with session lock held.
1115  */
1116 ssize_t trace_ust_list_tracker_ids(enum lttng_tracker_type tracker_type,
1117                 struct ltt_ust_session *session,
1118                 struct lttng_tracker_id ***_ids)
1119 {
1120         struct lttng_tracker_list *tracker_list;
1121
1122         if (tracker_type == LTTNG_TRACKER_PID) {
1123                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
1124                 tracker_type = LTTNG_TRACKER_VPID;
1125         }
1126
1127         tracker_list = get_id_tracker_list(session, tracker_type);
1128         if (!tracker_list) {
1129                 return -LTTNG_ERR_INVALID;
1130         }
1131         return lttng_tracker_id_get_list(tracker_list, _ids);
1132 }
1133
1134 /*
1135  * RCU safe free context structure.
1136  */
1137 static void destroy_context_rcu(struct rcu_head *head)
1138 {
1139         struct lttng_ht_node_ulong *node =
1140                 caa_container_of(head, struct lttng_ht_node_ulong, head);
1141         struct ltt_ust_context *ctx =
1142                 caa_container_of(node, struct ltt_ust_context, node);
1143
1144         trace_ust_destroy_context(ctx);
1145 }
1146
1147 /*
1148  * Cleanup UST context hash table.
1149  */
1150 static void destroy_contexts(struct lttng_ht *ht)
1151 {
1152         int ret;
1153         struct lttng_ht_node_ulong *node;
1154         struct lttng_ht_iter iter;
1155         struct ltt_ust_context *ctx;
1156
1157         assert(ht);
1158
1159         rcu_read_lock();
1160         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
1161                 /* Remove from ordered list. */
1162                 ctx = caa_container_of(node, struct ltt_ust_context, node);
1163                 cds_list_del(&ctx->list);
1164                 /* Remove from channel's hash table. */
1165                 ret = lttng_ht_del(ht, &iter);
1166                 if (!ret) {
1167                         call_rcu(&node->head, destroy_context_rcu);
1168                 }
1169         }
1170         rcu_read_unlock();
1171
1172         ht_cleanup_push(ht);
1173 }
1174
1175 /*
1176  * Cleanup ust event structure.
1177  */
1178 void trace_ust_destroy_event(struct ltt_ust_event *event)
1179 {
1180         assert(event);
1181
1182         DBG2("Trace destroy UST event %s", event->attr.name);
1183         free(event->filter_expression);
1184         free(event->filter);
1185         free(event->exclusion);
1186         free(event);
1187 }
1188
1189 /*
1190  * Cleanup ust context structure.
1191  */
1192 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1193 {
1194         assert(ctx);
1195
1196         if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1197                 free(ctx->ctx.u.app_ctx.provider_name);
1198                 free(ctx->ctx.u.app_ctx.ctx_name);
1199         }
1200         free(ctx);
1201 }
1202
1203 /*
1204  * URCU intermediate call to complete destroy event.
1205  */
1206 static void destroy_event_rcu(struct rcu_head *head)
1207 {
1208         struct lttng_ht_node_str *node =
1209                 caa_container_of(head, struct lttng_ht_node_str, head);
1210         struct ltt_ust_event *event =
1211                 caa_container_of(node, struct ltt_ust_event, node);
1212
1213         trace_ust_destroy_event(event);
1214 }
1215
1216 /*
1217  * Cleanup UST events hashtable.
1218  */
1219 static void destroy_events(struct lttng_ht *events)
1220 {
1221         int ret;
1222         struct lttng_ht_node_str *node;
1223         struct lttng_ht_iter iter;
1224
1225         assert(events);
1226
1227         rcu_read_lock();
1228         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1229                 ret = lttng_ht_del(events, &iter);
1230                 assert(!ret);
1231                 call_rcu(&node->head, destroy_event_rcu);
1232         }
1233         rcu_read_unlock();
1234
1235         ht_cleanup_push(events);
1236 }
1237
1238 /*
1239  * Cleanup ust channel structure.
1240  *
1241  * Should _NOT_ be called with RCU read lock held.
1242  */
1243 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1244 {
1245         assert(channel);
1246
1247         DBG2("Trace destroy UST channel %s", channel->name);
1248
1249         free(channel);
1250 }
1251
1252 /*
1253  * URCU intermediate call to complete destroy channel.
1254  */
1255 static void destroy_channel_rcu(struct rcu_head *head)
1256 {
1257         struct lttng_ht_node_str *node =
1258                 caa_container_of(head, struct lttng_ht_node_str, head);
1259         struct ltt_ust_channel *channel =
1260                 caa_container_of(node, struct ltt_ust_channel, node);
1261
1262         _trace_ust_destroy_channel(channel);
1263 }
1264
1265 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1266 {
1267         /* Destroying all events of the channel */
1268         destroy_events(channel->events);
1269         /* Destroying all context of the channel */
1270         destroy_contexts(channel->ctx);
1271
1272         call_rcu(&channel->node.head, destroy_channel_rcu);
1273 }
1274
1275 /*
1276  * Remove an UST channel from a channel HT.
1277  */
1278 void trace_ust_delete_channel(struct lttng_ht *ht,
1279                 struct ltt_ust_channel *channel)
1280 {
1281         int ret;
1282         struct lttng_ht_iter iter;
1283
1284         assert(ht);
1285         assert(channel);
1286
1287         iter.iter.node = &channel->node.node;
1288         ret = lttng_ht_del(ht, &iter);
1289         assert(!ret);
1290 }
1291
1292 /*
1293  * Iterate over a hash table containing channels and cleanup safely.
1294  */
1295 static void destroy_channels(struct lttng_ht *channels)
1296 {
1297         struct lttng_ht_node_str *node;
1298         struct lttng_ht_iter iter;
1299
1300         assert(channels);
1301
1302         rcu_read_lock();
1303         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1304                 struct ltt_ust_channel *chan =
1305                         caa_container_of(node, struct ltt_ust_channel, node);
1306
1307                 trace_ust_delete_channel(channels, chan);
1308                 trace_ust_destroy_channel(chan);
1309         }
1310         rcu_read_unlock();
1311
1312         ht_cleanup_push(channels);
1313 }
1314
1315 /*
1316  * Cleanup UST global domain.
1317  */
1318 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1319 {
1320         assert(dom);
1321
1322         destroy_channels(dom->channels);
1323 }
1324
1325 /*
1326  * Cleanup ust session structure, keeping data required by
1327  * destroy notifier.
1328  *
1329  * Should *NOT* be called with RCU read-side lock held.
1330  */
1331 void trace_ust_destroy_session(struct ltt_ust_session *session)
1332 {
1333         struct agent *agt;
1334         struct buffer_reg_uid *reg, *sreg;
1335         struct lttng_ht_iter iter;
1336
1337         assert(session);
1338
1339         DBG2("Trace UST destroy session %" PRIu64, session->id);
1340
1341         /* Cleaning up UST domain */
1342         destroy_domain_global(&session->domain_global);
1343
1344         rcu_read_lock();
1345         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1346                 int ret = lttng_ht_del(session->agents, &iter);
1347
1348                 assert(!ret);
1349                 agent_destroy(agt);
1350         }
1351         rcu_read_unlock();
1352
1353         ht_cleanup_push(session->agents);
1354
1355         /* Cleanup UID buffer registry object(s). */
1356         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1357                         lnode) {
1358                 cds_list_del(&reg->lnode);
1359                 buffer_reg_uid_remove(reg);
1360                 buffer_reg_uid_destroy(reg, session->consumer);
1361         }
1362
1363         lttng_tracker_list_destroy(session->tracker_list_vpid);
1364         lttng_tracker_list_destroy(session->tracker_list_vuid);
1365         lttng_tracker_list_destroy(session->tracker_list_vgid);
1366
1367         fini_id_tracker(&session->vpid_tracker);
1368         fini_id_tracker(&session->vuid_tracker);
1369         fini_id_tracker(&session->vgid_tracker);
1370         lttng_trace_chunk_put(session->current_trace_chunk);
1371 }
1372
1373 /* Free elements needed by destroy notifiers. */
1374 void trace_ust_free_session(struct ltt_ust_session *session)
1375 {
1376         consumer_output_put(session->consumer);
1377         free(session);
1378 }