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

   1 /*
   2  * Copyright (C) 2011 EfficiOS Inc.
   3  * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <inttypes.h>
  15
  16 #include <common/common.hpp>
  17 #include <common/defaults.hpp>
  18 #include <common/trace-chunk.hpp>
  19 #include <common/utils.hpp>
  20
  21 #include "buffer-registry.hpp"
  22 #include "trace-ust.hpp"
  23 #include "utils.hpp"
  24 #include "ust-app.hpp"
  25 #include "agent.hpp"
  26
  27 /*
  28  * Match function for the events hash table lookup.
  29  *
  30  * Matches by name only. Used by the disable command.
  31  */
  32 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  33                 const void *_key)
  34 {
  35         struct ltt_ust_event *event;
  36         const char *name;
  37
  38         LTTNG_ASSERT(node);
  39         LTTNG_ASSERT(_key);
  40
  41         event = caa_container_of(node, struct ltt_ust_event, node.node);
  42         name = (const char *) _key;
  43
  44         /* Event name */
  45         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  46                 goto no_match;
  47         }
  48
  49         /* Match */
  50         return 1;
  51
  52 no_match:
  53         return 0;
  54 }
  55
  56 /*
  57  * Match function for the hash table lookup.
  58  *
  59  * It matches an ust event based on three attributes which are the event name,
  60  * the filter bytecode and the loglevel.
  61  */
  62 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  63 {
  64         struct ltt_ust_event *event;
  65         const struct ltt_ust_ht_key *key;
  66         int ev_loglevel_value;
  67         int ll_match;
  68
  69         LTTNG_ASSERT(node);
  70         LTTNG_ASSERT(_key);
  71
  72         event = caa_container_of(node, struct ltt_ust_event, node.node);
  73         key = (ltt_ust_ht_key *) _key;
  74         ev_loglevel_value = event->attr.loglevel;
  75
  76         /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
  77
  78         /* Event name */
  79         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  80                 goto no_match;
  81         }
  82
  83         /* Event loglevel value and type. */
  84         ll_match = loglevels_match(event->attr.loglevel_type,
  85                 ev_loglevel_value, key->loglevel_type,
  86                 key->loglevel_value, LTTNG_UST_ABI_LOGLEVEL_ALL);
  87
  88         if (!ll_match) {
  89                 goto no_match;
  90         }
  91
  92         /* Only one of the filters is NULL, fail. */
  93         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
  94                 goto no_match;
  95         }
  96
  97         if (key->filter && event->filter) {
  98                 /* Both filters exists, check length followed by the bytecode. */
  99                 if (event->filter->len != key->filter->len ||
 100                                 memcmp(event->filter->data, key->filter->data,
 101                                         event->filter->len) != 0) {
 102                         goto no_match;
 103                 }
 104         }
 105
 106         /* If only one of the exclusions is NULL, fail. */
 107         if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
 108                 goto no_match;
 109         }
 110
 111         if (key->exclusion && event->exclusion) {
 112                 size_t i;
 113
 114                 /* Check exclusion counts first. */
 115                 if (event->exclusion->count != key->exclusion->count) {
 116                         goto no_match;
 117                 }
 118
 119                 /* Compare names individually. */
 120                 for (i = 0; i < event->exclusion->count; ++i) {
 121                         size_t j;
 122                         bool found = false;
 123                         const char *name_ev =
 124                                 LTTNG_EVENT_EXCLUSION_NAME_AT(
 125                                         event->exclusion, i);
 126
 127                         /*
 128                          * Compare this exclusion name to all the key's
 129                          * exclusion names.
 130                          */
 131                         for (j = 0; j < key->exclusion->count; ++j) {
 132                                 const char *name_key =
 133                                         LTTNG_EVENT_EXCLUSION_NAME_AT(
 134                                                 key->exclusion, j);
 135
 136                                 if (!strncmp(name_ev, name_key,
 137                                                 LTTNG_SYMBOL_NAME_LEN)) {
 138                                         /* Names match! */
 139                                         found = true;
 140                                         break;
 141                                 }
 142                         }
 143
 144                         /*
 145                          * If the current exclusion name was not found amongst
 146                          * the key's exclusion names, then there's no match.
 147                          */
 148                         if (!found) {
 149                                 goto no_match;
 150                         }
 151                 }
 152         }
 153         /* Match. */
 154         return 1;
 155
 156 no_match:
 157         return 0;
 158 }
 159
 160 /*
 161  * Find the channel in the hashtable and return channel pointer. RCU read side
 162  * lock MUST be acquired before calling this.
 163  */
 164 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 165                 const char *name)
 166 {
 167         struct lttng_ht_node_str *node;
 168         struct lttng_ht_iter iter;
 169
 170         ASSERT_RCU_READ_LOCKED();
 171         /*
 172          * If we receive an empty string for channel name, it means the
 173          * default channel name is requested.
 174          */
 175         if (name[0] == '\0')
 176                 name = DEFAULT_CHANNEL_NAME;
 177
 178         lttng_ht_lookup(ht, (void *)name, &iter);
 179         node = lttng_ht_iter_get_node_str(&iter);
 180         if (node == NULL) {
 181                 goto error;
 182         }
 183
 184         DBG2("Trace UST channel %s found by name", name);
 185
 186         return caa_container_of(node, struct ltt_ust_channel, node);
 187
 188 error:
 189         DBG2("Trace UST channel %s not found by name", name);
 190         return NULL;
 191 }
 192
 193 /*
 194  * Find the event in the hashtable and return event pointer. RCU read side lock
 195  * MUST be acquired before calling this.
 196  */
 197 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 198                 char *name, struct lttng_bytecode *filter,
 199                 enum lttng_ust_abi_loglevel_type loglevel_type, int loglevel_value,
 200                 struct lttng_event_exclusion *exclusion)
 201 {
 202         struct lttng_ht_node_str *node;
 203         struct lttng_ht_iter iter;
 204         struct ltt_ust_ht_key key;
 205
 206         LTTNG_ASSERT(name);
 207         LTTNG_ASSERT(ht);
 208         ASSERT_RCU_READ_LOCKED();
 209
 210         key.name = name;
 211         key.filter = filter;
 212         key.loglevel_type = loglevel_type;
 213         key.loglevel_value = loglevel_value;
 214         key.exclusion = exclusion;
 215
 216         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 217                         trace_ust_ht_match_event, &key, &iter.iter);
 218         node = lttng_ht_iter_get_node_str(&iter);
 219         if (node == NULL) {
 220                 goto error;
 221         }
 222
 223         DBG2("Trace UST event %s found", key.name);
 224
 225         return caa_container_of(node, struct ltt_ust_event, node);
 226
 227 error:
 228         DBG2("Trace UST event %s NOT found", key.name);
 229         return NULL;
 230 }
 231
 232 /*
 233  * Lookup an agent in the session agents hash table by domain type and return
 234  * the object if found else NULL.
 235  *
 236  * RCU read side lock must be acquired before calling and only released
 237  * once the agent is no longer in scope or being used.
 238  */
 239 struct agent *trace_ust_find_agent(struct ltt_ust_session *session,
 240                 enum lttng_domain_type domain_type)
 241 {
 242         struct agent *agt = NULL;
 243         struct lttng_ht_node_u64 *node;
 244         struct lttng_ht_iter iter;
 245         uint64_t key;
 246
 247         LTTNG_ASSERT(session);
 248
 249         DBG3("Trace ust agent lookup for domain %d", domain_type);
 250
 251         key = domain_type;
 252
 253         lttng_ht_lookup(session->agents, &key, &iter);
 254         node = lttng_ht_iter_get_node_u64(&iter);
 255         if (!node) {
 256                 goto end;
 257         }
 258         agt = caa_container_of(node, struct agent, node);
 259
 260 end:
 261         return agt;
 262 }
 263
 264 /*
 265  * Allocate and initialize a ust session data structure.
 266  *
 267  * Return pointer to structure or NULL.
 268  */
 269 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 270 {
 271         struct ltt_ust_session *lus;
 272
 273         /* Allocate a new ltt ust session */
 274         lus = zmalloc<ltt_ust_session>();
 275         if (lus == NULL) {
 276                 PERROR("create ust session zmalloc");
 277                 goto error_alloc;
 278         }
 279
 280         /* Init data structure */
 281         lus->id = session_id;
 282         lus->active = 0;
 283
 284         /* Set default metadata channel attribute. */
 285         lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 286         lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
 287         lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 288         lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 289         lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 290         lus->metadata_attr.output = LTTNG_UST_ABI_MMAP;
 291
 292         /*
 293          * Default buffer type. This can be changed through an enable channel
 294          * requesting a different type. Note that this can only be changed once
 295          * during the session lifetime which is at the first enable channel and
 296          * only before start. The flag buffer_type_changed indicates the status.
 297          */
 298         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 299         /* Once set to 1, the buffer_type is immutable for the session. */
 300         lus->buffer_type_changed = 0;
 301         /* Init it in case it get used after allocation. */
 302         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 303
 304         /* Alloc UST global domain channels' HT */
 305         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 306         /* Alloc agent hash table. */
 307         lus->agents = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 308
 309         lus->tracker_vpid = process_attr_tracker_create();
 310         if (!lus->tracker_vpid) {
 311                 goto error;
 312         }
 313         lus->tracker_vuid = process_attr_tracker_create();
 314         if (!lus->tracker_vuid) {
 315                 goto error;
 316         }
 317         lus->tracker_vgid = process_attr_tracker_create();
 318         if (!lus->tracker_vgid) {
 319                 goto error;
 320         }
 321         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 322         if (lus->consumer == NULL) {
 323                 goto error;
 324         }
 325
 326         DBG2("UST trace session create successful");
 327
 328         return lus;
 329
 330 error:
 331         process_attr_tracker_destroy(lus->tracker_vpid);
 332         process_attr_tracker_destroy(lus->tracker_vuid);
 333         process_attr_tracker_destroy(lus->tracker_vgid);
 334         lttng_ht_destroy(lus->domain_global.channels);
 335         lttng_ht_destroy(lus->agents);
 336         free(lus);
 337 error_alloc:
 338         return NULL;
 339 }
 340
 341 /*
 342  * Allocate and initialize a ust channel data structure.
 343  *
 344  * Return pointer to structure or NULL.
 345  */
 346 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 347                 enum lttng_domain_type domain)
 348 {
 349         struct ltt_ust_channel *luc;
 350
 351         LTTNG_ASSERT(chan);
 352
 353         luc = zmalloc<ltt_ust_channel>();
 354         if (luc == NULL) {
 355                 PERROR("ltt_ust_channel zmalloc");
 356                 goto error;
 357         }
 358
 359         luc->domain = domain;
 360
 361         /* Copy UST channel attributes */
 362         luc->attr.overwrite = chan->attr.overwrite;
 363         luc->attr.subbuf_size = chan->attr.subbuf_size;
 364         luc->attr.num_subbuf = chan->attr.num_subbuf;
 365         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 366         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 367         luc->attr.output = (enum lttng_ust_abi_output) chan->attr.output;
 368         luc->monitor_timer_interval = ((struct lttng_channel_extended *)
 369                         chan->attr.extended.ptr)->monitor_timer_interval;
 370         luc->attr.u.s.blocking_timeout = ((struct lttng_channel_extended *)
 371                         chan->attr.extended.ptr)->blocking_timeout;
 372
 373         /* Translate to UST output enum */
 374         switch (luc->attr.output) {
 375         default:
 376                 luc->attr.output = LTTNG_UST_ABI_MMAP;
 377                 break;
 378         }
 379
 380         /*
 381          * If we receive an empty string for channel name, it means the
 382          * default channel name is requested.
 383          */
 384         if (chan->name[0] == '\0') {
 385                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 386         } else {
 387                 /* Copy channel name */
 388                 strncpy(luc->name, chan->name, sizeof(luc->name));
 389         }
 390         luc->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
 391
 392         /* Init node */
 393         lttng_ht_node_init_str(&luc->node, luc->name);
 394         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 395
 396         /* Alloc hash tables */
 397         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 398         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 399
 400         /* On-disk circular buffer parameters */
 401         luc->tracefile_size = chan->attr.tracefile_size;
 402         luc->tracefile_count = chan->attr.tracefile_count;
 403
 404         DBG2("Trace UST channel %s created", luc->name);
 405
 406 error:
 407         return luc;
 408 }
 409
 410 /*
 411  * Validates an exclusion list.
 412  *
 413  * Returns 0 if valid, negative value if invalid.
 414  */
 415 static int validate_exclusion(struct lttng_event_exclusion *exclusion)
 416 {
 417         size_t i;
 418         int ret = 0;
 419
 420         LTTNG_ASSERT(exclusion);
 421
 422         for (i = 0; i < exclusion->count; ++i) {
 423                 size_t j;
 424                 const char *name_a =
 425                         LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
 426
 427                 for (j = 0; j < i; ++j) {
 428                         const char *name_b =
 429                                 LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, j);
 430
 431                         if (!strncmp(name_a, name_b, LTTNG_SYMBOL_NAME_LEN)) {
 432                                 /* Match! */
 433                                 ret = -1;
 434                                 goto end;
 435                         }
 436                 }
 437         }
 438
 439 end:
 440         return ret;
 441 }
 442
 443 /*
 444  * Allocate and initialize a ust event. Set name and event type.
 445  * We own filter_expression, filter, and exclusion.
 446  *
 447  * Return an lttng_error_code
 448  */
 449 enum lttng_error_code trace_ust_create_event(struct lttng_event *ev,
 450                 char *filter_expression,
 451                 struct lttng_bytecode *filter,
 452                 struct lttng_event_exclusion *exclusion,
 453                 bool internal_event,
 454                 struct ltt_ust_event **ust_event)
 455 {
 456         struct ltt_ust_event *local_ust_event;
 457         enum lttng_error_code ret = LTTNG_OK;
 458
 459         LTTNG_ASSERT(ev);
 460
 461         if (exclusion && validate_exclusion(exclusion)) {
 462                 ret = LTTNG_ERR_INVALID;
 463                 goto error;
 464         }
 465
 466         local_ust_event = zmalloc<ltt_ust_event>();
 467         if (local_ust_event == NULL) {
 468                 PERROR("ust event zmalloc");
 469                 ret = LTTNG_ERR_NOMEM;
 470                 goto error;
 471         }
 472
 473         local_ust_event->internal = internal_event;
 474
 475         switch (ev->type) {
 476         case LTTNG_EVENT_PROBE:
 477                 local_ust_event->attr.instrumentation = LTTNG_UST_ABI_PROBE;
 478                 break;
 479         case LTTNG_EVENT_FUNCTION:
 480                 local_ust_event->attr.instrumentation = LTTNG_UST_ABI_FUNCTION;
 481                 break;
 482         case LTTNG_EVENT_FUNCTION_ENTRY:
 483                 local_ust_event->attr.instrumentation = LTTNG_UST_ABI_FUNCTION;
 484                 break;
 485         case LTTNG_EVENT_TRACEPOINT:
 486                 local_ust_event->attr.instrumentation = LTTNG_UST_ABI_TRACEPOINT;
 487                 break;
 488         default:
 489                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 490                 ret = LTTNG_ERR_INVALID;
 491                 goto error_free_event;
 492         }
 493
 494         /* Copy event name */
 495         strncpy(local_ust_event->attr.name, ev->name, LTTNG_UST_ABI_SYM_NAME_LEN);
 496         local_ust_event->attr.name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
 497
 498         switch (ev->loglevel_type) {
 499         case LTTNG_EVENT_LOGLEVEL_ALL:
 500                 local_ust_event->attr.loglevel_type = LTTNG_UST_ABI_LOGLEVEL_ALL;
 501                 local_ust_event->attr.loglevel = -1;    /* Force to -1 */
 502                 break;
 503         case LTTNG_EVENT_LOGLEVEL_RANGE:
 504                 local_ust_event->attr.loglevel_type = LTTNG_UST_ABI_LOGLEVEL_RANGE;
 505                 local_ust_event->attr.loglevel = ev->loglevel;
 506                 break;
 507         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 508                 local_ust_event->attr.loglevel_type = LTTNG_UST_ABI_LOGLEVEL_SINGLE;
 509                 local_ust_event->attr.loglevel = ev->loglevel;
 510                 break;
 511         default:
 512                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 513                 ret = LTTNG_ERR_INVALID;
 514                 goto error_free_event;
 515         }
 516
 517         /* Same layout. */
 518         local_ust_event->filter_expression = filter_expression;
 519         local_ust_event->filter = filter;
 520         local_ust_event->exclusion = exclusion;
 521
 522         /* Init node */
 523         lttng_ht_node_init_str(&local_ust_event->node, local_ust_event->attr.name);
 524
 525         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 526                 local_ust_event->attr.name, local_ust_event->attr.loglevel_type,
 527                 local_ust_event->attr.loglevel);
 528
 529         *ust_event = local_ust_event;
 530
 531         return ret;
 532
 533 error_free_event:
 534         free(local_ust_event);
 535 error:
 536         free(filter_expression);
 537         free(filter);
 538         free(exclusion);
 539         return ret;
 540 }
 541
 542 static
 543 int trace_ust_context_type_event_to_ust(
 544                 enum lttng_event_context_type type)
 545 {
 546         int utype;
 547
 548         switch (type) {
 549         case LTTNG_EVENT_CONTEXT_VTID:
 550                 utype = LTTNG_UST_ABI_CONTEXT_VTID;
 551                 break;
 552         case LTTNG_EVENT_CONTEXT_VPID:
 553                 utype = LTTNG_UST_ABI_CONTEXT_VPID;
 554                 break;
 555         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 556                 utype = LTTNG_UST_ABI_CONTEXT_PTHREAD_ID;
 557                 break;
 558         case LTTNG_EVENT_CONTEXT_PROCNAME:
 559                 utype = LTTNG_UST_ABI_CONTEXT_PROCNAME;
 560                 break;
 561         case LTTNG_EVENT_CONTEXT_IP:
 562                 utype = LTTNG_UST_ABI_CONTEXT_IP;
 563                 break;
 564         case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
 565                 if (!lttng_ust_ctl_has_perf_counters()) {
 566                         utype = -1;
 567                         WARN("Perf counters not implemented in UST");
 568                 } else {
 569                         utype = LTTNG_UST_ABI_CONTEXT_PERF_THREAD_COUNTER;
 570                 }
 571                 break;
 572         case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
 573                 utype = LTTNG_UST_ABI_CONTEXT_APP_CONTEXT;
 574                 break;
 575         case LTTNG_EVENT_CONTEXT_CGROUP_NS:
 576                 utype = LTTNG_UST_ABI_CONTEXT_CGROUP_NS;
 577                 break;
 578         case LTTNG_EVENT_CONTEXT_IPC_NS:
 579                 utype = LTTNG_UST_ABI_CONTEXT_IPC_NS;
 580                 break;
 581         case LTTNG_EVENT_CONTEXT_MNT_NS:
 582                 utype = LTTNG_UST_ABI_CONTEXT_MNT_NS;
 583                 break;
 584         case LTTNG_EVENT_CONTEXT_NET_NS:
 585                 utype = LTTNG_UST_ABI_CONTEXT_NET_NS;
 586                 break;
 587         case LTTNG_EVENT_CONTEXT_PID_NS:
 588                 utype = LTTNG_UST_ABI_CONTEXT_PID_NS;
 589                 break;
 590         case LTTNG_EVENT_CONTEXT_TIME_NS:
 591                 utype = LTTNG_UST_ABI_CONTEXT_TIME_NS;
 592                 break;
 593         case LTTNG_EVENT_CONTEXT_USER_NS:
 594                 utype = LTTNG_UST_ABI_CONTEXT_USER_NS;
 595                 break;
 596         case LTTNG_EVENT_CONTEXT_UTS_NS:
 597                 utype = LTTNG_UST_ABI_CONTEXT_UTS_NS;
 598                 break;
 599         case LTTNG_EVENT_CONTEXT_VUID:
 600                 utype = LTTNG_UST_ABI_CONTEXT_VUID;
 601                 break;
 602         case LTTNG_EVENT_CONTEXT_VEUID:
 603                 utype = LTTNG_UST_ABI_CONTEXT_VEUID;
 604                 break;
 605         case LTTNG_EVENT_CONTEXT_VSUID:
 606                 utype = LTTNG_UST_ABI_CONTEXT_VSUID;
 607                 break;
 608         case LTTNG_EVENT_CONTEXT_VGID:
 609                 utype = LTTNG_UST_ABI_CONTEXT_VGID;
 610                 break;
 611         case LTTNG_EVENT_CONTEXT_VEGID:
 612                 utype = LTTNG_UST_ABI_CONTEXT_VEGID;
 613                 break;
 614         case LTTNG_EVENT_CONTEXT_VSGID:
 615                 utype = LTTNG_UST_ABI_CONTEXT_VSGID;
 616                 break;
 617         default:
 618                 utype = -1;
 619                 break;
 620         }
 621         return utype;
 622 }
 623
 624 /*
 625  * Return 1 if contexts match, 0 otherwise.
 626  */
 627 int trace_ust_match_context(const struct ltt_ust_context *uctx,
 628                 const struct lttng_event_context *ctx)
 629 {
 630         int utype;
 631
 632         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 633         if (utype < 0) {
 634                 return 0;
 635         }
 636         if (uctx->ctx.ctx != utype) {
 637                 return 0;
 638         }
 639         switch (utype) {
 640         case LTTNG_UST_ABI_CONTEXT_PERF_THREAD_COUNTER:
 641                 if (uctx->ctx.u.perf_counter.type
 642                                 != ctx->u.perf_counter.type) {
 643                         return 0;
 644                 }
 645                 if (uctx->ctx.u.perf_counter.config
 646                                 != ctx->u.perf_counter.config) {
 647                         return 0;
 648                 }
 649                 if (strncmp(uctx->ctx.u.perf_counter.name,
 650                                 ctx->u.perf_counter.name,
 651                                 LTTNG_UST_ABI_SYM_NAME_LEN)) {
 652                         return 0;
 653                 }
 654                 break;
 655         case LTTNG_UST_ABI_CONTEXT_APP_CONTEXT:
 656                 LTTNG_ASSERT(uctx->ctx.u.app_ctx.provider_name);
 657                 LTTNG_ASSERT(uctx->ctx.u.app_ctx.ctx_name);
 658                 if (strcmp(uctx->ctx.u.app_ctx.provider_name,
 659                                 ctx->u.app_ctx.provider_name) ||
 660                                 strcmp(uctx->ctx.u.app_ctx.ctx_name,
 661                                 ctx->u.app_ctx.ctx_name)) {
 662                         return 0;
 663                 }
 664         default:
 665                 break;
 666
 667         }
 668         return 1;
 669 }
 670
 671 /*
 672  * Allocate and initialize an UST context.
 673  *
 674  * Return pointer to structure or NULL.
 675  */
 676 struct ltt_ust_context *trace_ust_create_context(
 677                 const struct lttng_event_context *ctx)
 678 {
 679         struct ltt_ust_context *uctx = NULL;
 680         int utype;
 681
 682         LTTNG_ASSERT(ctx);
 683
 684         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 685         if (utype < 0) {
 686                 ERR("Invalid UST context");
 687                 goto end;
 688         }
 689
 690         uctx = zmalloc<ltt_ust_context>();
 691         if (!uctx) {
 692                 PERROR("zmalloc ltt_ust_context");
 693                 goto end;
 694         }
 695
 696         uctx->ctx.ctx = (enum lttng_ust_abi_context_type) utype;
 697         switch (utype) {
 698         case LTTNG_UST_ABI_CONTEXT_PERF_THREAD_COUNTER:
 699                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 700                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 701                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 702                                 LTTNG_UST_ABI_SYM_NAME_LEN);
 703                 uctx->ctx.u.perf_counter.name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
 704                 break;
 705         case LTTNG_UST_ABI_CONTEXT_APP_CONTEXT:
 706         {
 707                 char *provider_name = NULL, *ctx_name = NULL;
 708
 709                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 710                 if (!provider_name) {
 711                         goto error;
 712                 }
 713                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 714
 715                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 716                 if (!ctx_name) {
 717                         goto error;
 718                 }
 719                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 720                 break;
 721         }
 722         default:
 723                 break;
 724         }
 725         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 726 end:
 727         return uctx;
 728 error:
 729         trace_ust_destroy_context(uctx);
 730         return NULL;
 731 }
 732
 733 static void destroy_id_tracker_node_rcu(struct rcu_head *head)
 734 {
 735         struct ust_id_tracker_node *tracker_node = caa_container_of(
 736                         head, struct ust_id_tracker_node, node.head);
 737         free(tracker_node);
 738 }
 739
 740 static void destroy_id_tracker_node(struct ust_id_tracker_node *tracker_node)
 741 {
 742         call_rcu(&tracker_node->node.head, destroy_id_tracker_node_rcu);
 743 }
 744
 745 static int init_id_tracker(struct ust_id_tracker *id_tracker)
 746 {
 747         int ret = LTTNG_OK;
 748
 749         id_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 750         if (!id_tracker->ht) {
 751                 ret = LTTNG_ERR_NOMEM;
 752                 goto end;
 753         }
 754
 755 end:
 756         return ret;
 757 }
 758
 759 /*
 760  * Teardown id tracker content, but don't free id_tracker object.
 761  */
 762 static void fini_id_tracker(struct ust_id_tracker *id_tracker)
 763 {
 764         struct ust_id_tracker_node *tracker_node;
 765         struct lttng_ht_iter iter;
 766
 767         if (!id_tracker->ht) {
 768                 return;
 769         }
 770         rcu_read_lock();
 771         cds_lfht_for_each_entry (id_tracker->ht->ht, &iter.iter, tracker_node,
 772                         node.node) {
 773                 int ret = lttng_ht_del(id_tracker->ht, &iter);
 774
 775                 LTTNG_ASSERT(!ret);
 776                 destroy_id_tracker_node(tracker_node);
 777         }
 778         rcu_read_unlock();
 779         lttng_ht_destroy(id_tracker->ht);
 780         id_tracker->ht = NULL;
 781 }
 782
 783 static struct ust_id_tracker_node *id_tracker_lookup(
 784                 struct ust_id_tracker *id_tracker,
 785                 int id,
 786                 struct lttng_ht_iter *iter)
 787 {
 788         unsigned long _id = (unsigned long) id;
 789         struct lttng_ht_node_ulong *node;
 790
 791         lttng_ht_lookup(id_tracker->ht, (void *) _id, iter);
 792         node = lttng_ht_iter_get_node_ulong(iter);
 793         if (node) {
 794                 return caa_container_of(node, struct ust_id_tracker_node, node);
 795         } else {
 796                 return NULL;
 797         }
 798 }
 799
 800 static int id_tracker_add_id(struct ust_id_tracker *id_tracker, int id)
 801 {
 802         int retval = LTTNG_OK;
 803         struct ust_id_tracker_node *tracker_node;
 804         struct lttng_ht_iter iter;
 805
 806         if (id < 0) {
 807                 retval = LTTNG_ERR_INVALID;
 808                 goto end;
 809         }
 810         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 811         if (tracker_node) {
 812                 /* Already exists. */
 813                 retval = LTTNG_ERR_PROCESS_ATTR_EXISTS;
 814                 goto end;
 815         }
 816         tracker_node = zmalloc<ust_id_tracker_node>();
 817         if (!tracker_node) {
 818                 retval = LTTNG_ERR_NOMEM;
 819                 goto end;
 820         }
 821         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) id);
 822         lttng_ht_add_unique_ulong(id_tracker->ht, &tracker_node->node);
 823 end:
 824         return retval;
 825 }
 826
 827 static int id_tracker_del_id(struct ust_id_tracker *id_tracker, int id)
 828 {
 829         int retval = LTTNG_OK, ret;
 830         struct ust_id_tracker_node *tracker_node;
 831         struct lttng_ht_iter iter;
 832
 833         if (id < 0) {
 834                 retval = LTTNG_ERR_INVALID;
 835                 goto end;
 836         }
 837         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 838         if (!tracker_node) {
 839                 /* Not found */
 840                 retval = LTTNG_ERR_PROCESS_ATTR_MISSING;
 841                 goto end;
 842         }
 843         ret = lttng_ht_del(id_tracker->ht, &iter);
 844         LTTNG_ASSERT(!ret);
 845
 846         destroy_id_tracker_node(tracker_node);
 847 end:
 848         return retval;
 849 }
 850
 851 static struct ust_id_tracker *get_id_tracker(struct ltt_ust_session *session,
 852                 enum lttng_process_attr process_attr)
 853 {
 854         switch (process_attr) {
 855         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
 856                 return &session->vpid_tracker;
 857         case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
 858                 return &session->vuid_tracker;
 859         case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
 860                 return &session->vgid_tracker;
 861         default:
 862                 return NULL;
 863         }
 864 }
 865
 866 static struct process_attr_tracker *_trace_ust_get_process_attr_tracker(
 867                 struct ltt_ust_session *session,
 868                 enum lttng_process_attr process_attr)
 869 {
 870         switch (process_attr) {
 871         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
 872                 return session->tracker_vpid;
 873         case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
 874                 return session->tracker_vuid;
 875         case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
 876                 return session->tracker_vgid;
 877         default:
 878                 return NULL;
 879         }
 880 }
 881
 882 const struct process_attr_tracker *trace_ust_get_process_attr_tracker(
 883                 struct ltt_ust_session *session,
 884                 enum lttng_process_attr process_attr)
 885 {
 886         return (const struct process_attr_tracker *)
 887                         _trace_ust_get_process_attr_tracker(
 888                                         session, process_attr);
 889 }
 890
 891 /*
 892  * The session lock is held when calling this function.
 893  */
 894 int trace_ust_id_tracker_lookup(enum lttng_process_attr process_attr,
 895                 struct ltt_ust_session *session,
 896                 int id)
 897 {
 898         struct lttng_ht_iter iter;
 899         struct ust_id_tracker *id_tracker;
 900
 901         id_tracker = get_id_tracker(session, process_attr);
 902         if (!id_tracker) {
 903                 abort();
 904         }
 905         if (!id_tracker->ht) {
 906                 return 1;
 907         }
 908         if (id_tracker_lookup(id_tracker, id, &iter)) {
 909                 return 1;
 910         }
 911         return 0;
 912 }
 913
 914 /*
 915  * Called with the session lock held.
 916  */
 917 enum lttng_error_code trace_ust_process_attr_tracker_set_tracking_policy(
 918                 struct ltt_ust_session *session,
 919                 enum lttng_process_attr process_attr,
 920                 enum lttng_tracking_policy policy)
 921 {
 922         int ret;
 923         enum lttng_error_code ret_code = LTTNG_OK;
 924         struct ust_id_tracker *id_tracker =
 925                         get_id_tracker(session, process_attr);
 926         struct process_attr_tracker *tracker =
 927                         _trace_ust_get_process_attr_tracker(
 928                                         session, process_attr);
 929         bool should_update_apps = false;
 930         enum lttng_tracking_policy previous_policy;
 931
 932         if (!tracker) {
 933                 ret_code = LTTNG_ERR_INVALID;
 934                 goto end;
 935         }
 936
 937         previous_policy = process_attr_tracker_get_tracking_policy(tracker);
 938         ret = process_attr_tracker_set_tracking_policy(tracker, policy);
 939         if (ret) {
 940                 ret_code = LTTNG_ERR_UNK;
 941                 goto end;
 942         }
 943
 944         if (previous_policy == policy) {
 945                 goto end;
 946         }
 947
 948         switch (policy) {
 949         case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
 950                 /* Track all values: destroy tracker if exists. */
 951                 if (id_tracker->ht) {
 952                         fini_id_tracker(id_tracker);
 953                         /* Ensure all apps have session. */
 954                         should_update_apps = true;
 955                 }
 956                 break;
 957         case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
 958         case LTTNG_TRACKING_POLICY_INCLUDE_SET:
 959                 /* fall-through. */
 960                 fini_id_tracker(id_tracker);
 961                 ret_code = (lttng_error_code) init_id_tracker(id_tracker);
 962                 if (ret_code != LTTNG_OK) {
 963                         ERR("Error initializing ID tracker");
 964                         goto end;
 965                 }
 966                 /* Remove all apps from session. */
 967                 should_update_apps = true;
 968                 break;
 969         default:
 970                 abort();
 971         }
 972         if (should_update_apps && session->active) {
 973                 ust_app_global_update_all(session);
 974         }
 975 end:
 976         return ret_code;
 977 }
 978
 979 /* Called with the session lock held. */
 980 enum lttng_error_code trace_ust_process_attr_tracker_inclusion_set_add_value(
 981                 struct ltt_ust_session *session,
 982                 enum lttng_process_attr process_attr,
 983                 const struct process_attr_value *value)
 984 {
 985         enum lttng_error_code ret_code = LTTNG_OK;
 986         bool should_update_apps = false;
 987         struct ust_id_tracker *id_tracker =
 988                         get_id_tracker(session, process_attr);
 989         struct process_attr_tracker *tracker;
 990         int integral_value;
 991         enum process_attr_tracker_status status;
 992         struct ust_app *app;
 993
 994         /*
 995          * Convert process attribute tracker value to the integral
 996          * representation required by the kern-ctl API.
 997          */
 998         switch (process_attr) {
 999         case LTTNG_PROCESS_ATTR_PROCESS_ID:
1000         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
1001                 integral_value = (int) value->value.pid;
1002                 break;
1003         case LTTNG_PROCESS_ATTR_USER_ID:
1004         case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
1005                 if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
1006                         uid_t uid;
1007
1008                         ret_code = utils_user_id_from_name(
1009                                         value->value.user_name, &uid);
1010                         if (ret_code != LTTNG_OK) {
1011                                 goto end;
1012                         }
1013                         integral_value = (int) uid;
1014                 } else {
1015                         integral_value = (int) value->value.uid;
1016                 }
1017                 break;
1018         case LTTNG_PROCESS_ATTR_GROUP_ID:
1019         case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
1020                 if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
1021                         gid_t gid;
1022
1023                         ret_code = utils_group_id_from_name(
1024                                         value->value.group_name, &gid);
1025                         if (ret_code != LTTNG_OK) {
1026                                 goto end;
1027                         }
1028                         integral_value = (int) gid;
1029                 } else {
1030                         integral_value = (int) value->value.gid;
1031                 }
1032                 break;
1033         default:
1034                 ret_code = LTTNG_ERR_INVALID;
1035                 goto end;
1036         }
1037
1038         tracker = _trace_ust_get_process_attr_tracker(session, process_attr);
1039         if (!tracker) {
1040                 ret_code = LTTNG_ERR_INVALID;
1041                 goto end;
1042         }
1043
1044         status = process_attr_tracker_inclusion_set_add_value(tracker, value);
1045         if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
1046                 switch (status) {
1047                 case PROCESS_ATTR_TRACKER_STATUS_EXISTS:
1048                         ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
1049                         break;
1050                 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1051                         ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1052                         break;
1053                 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1054                 default:
1055                         ret_code = LTTNG_ERR_UNK;
1056                         break;
1057                 }
1058                 goto end;
1059         }
1060
1061         DBG("User space track %s %d for session id %" PRIu64,
1062                         lttng_process_attr_to_string(process_attr),
1063                         integral_value, session->id);
1064
1065         ret_code = (lttng_error_code) id_tracker_add_id(id_tracker, integral_value);
1066         if (ret_code != LTTNG_OK) {
1067                 goto end;
1068         }
1069         /* Add session to application */
1070         switch (process_attr) {
1071         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
1072                 app = ust_app_find_by_pid(integral_value);
1073                 if (app) {
1074                         should_update_apps = true;
1075                 }
1076                 break;
1077         default:
1078                 should_update_apps = true;
1079                 break;
1080         }
1081         if (should_update_apps && session->active) {
1082                 ust_app_global_update_all(session);
1083         }
1084 end:
1085         return ret_code;
1086 }
1087
1088 /* Called with the session lock held. */
1089 enum lttng_error_code trace_ust_process_attr_tracker_inclusion_set_remove_value(
1090                 struct ltt_ust_session *session,
1091                 enum lttng_process_attr process_attr,
1092                 const struct process_attr_value *value)
1093 {
1094         enum lttng_error_code ret_code = LTTNG_OK;
1095         bool should_update_apps = false;
1096         struct ust_id_tracker *id_tracker =
1097                         get_id_tracker(session, process_attr);
1098         struct process_attr_tracker *tracker;
1099         int integral_value;
1100         enum process_attr_tracker_status status;
1101         struct ust_app *app;
1102
1103         /*
1104          * Convert process attribute tracker value to the integral
1105          * representation required by the kern-ctl API.
1106          */
1107         switch (process_attr) {
1108         case LTTNG_PROCESS_ATTR_PROCESS_ID:
1109         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
1110                 integral_value = (int) value->value.pid;
1111                 break;
1112         case LTTNG_PROCESS_ATTR_USER_ID:
1113         case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
1114                 if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
1115                         uid_t uid;
1116
1117                         ret_code = utils_user_id_from_name(
1118                                         value->value.user_name, &uid);
1119                         if (ret_code != LTTNG_OK) {
1120                                 goto end;
1121                         }
1122                         integral_value = (int) uid;
1123                 } else {
1124                         integral_value = (int) value->value.uid;
1125                 }
1126                 break;
1127         case LTTNG_PROCESS_ATTR_GROUP_ID:
1128         case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
1129                 if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
1130                         gid_t gid;
1131
1132                         ret_code = utils_group_id_from_name(
1133                                         value->value.group_name, &gid);
1134                         if (ret_code != LTTNG_OK) {
1135                                 goto end;
1136                         }
1137                         integral_value = (int) gid;
1138                 } else {
1139                         integral_value = (int) value->value.gid;
1140                 }
1141                 break;
1142         default:
1143                 ret_code = LTTNG_ERR_INVALID;
1144                 goto end;
1145         }
1146
1147         tracker = _trace_ust_get_process_attr_tracker(session, process_attr);
1148         if (!tracker) {
1149                 ret_code = LTTNG_ERR_INVALID;
1150                 goto end;
1151         }
1152
1153         status = process_attr_tracker_inclusion_set_remove_value(
1154                         tracker, value);
1155         if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
1156                 switch (status) {
1157                 case PROCESS_ATTR_TRACKER_STATUS_MISSING:
1158                         ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING;
1159                         break;
1160                 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1161                         ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1162                         break;
1163                 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1164                 default:
1165                         ret_code = LTTNG_ERR_UNK;
1166                         break;
1167                 }
1168                 goto end;
1169         }
1170
1171         DBG("User space untrack %s %d for session id %" PRIu64,
1172                         lttng_process_attr_to_string(process_attr),
1173                         integral_value, session->id);
1174
1175         ret_code = (lttng_error_code) id_tracker_del_id(id_tracker, integral_value);
1176         if (ret_code != LTTNG_OK) {
1177                 goto end;
1178         }
1179         /* Add session to application */
1180         switch (process_attr) {
1181         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
1182                 app = ust_app_find_by_pid(integral_value);
1183                 if (app) {
1184                         should_update_apps = true;
1185                 }
1186                 break;
1187         default:
1188                 should_update_apps = true;
1189                 break;
1190         }
1191         if (should_update_apps && session->active) {
1192                 ust_app_global_update_all(session);
1193         }
1194 end:
1195         return ret_code;
1196 }
1197
1198 /*
1199  * RCU safe free context structure.
1200  */
1201 static void destroy_context_rcu(struct rcu_head *head)
1202 {
1203         struct lttng_ht_node_ulong *node =
1204                 caa_container_of(head, struct lttng_ht_node_ulong, head);
1205         struct ltt_ust_context *ctx =
1206                 caa_container_of(node, struct ltt_ust_context, node);
1207
1208         trace_ust_destroy_context(ctx);
1209 }
1210
1211 /*
1212  * Cleanup UST context hash table.
1213  */
1214 static void destroy_contexts(struct lttng_ht *ht)
1215 {
1216         int ret;
1217         struct lttng_ht_node_ulong *node;
1218         struct lttng_ht_iter iter;
1219         struct ltt_ust_context *ctx;
1220
1221         LTTNG_ASSERT(ht);
1222
1223         rcu_read_lock();
1224         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
1225                 /* Remove from ordered list. */
1226                 ctx = caa_container_of(node, struct ltt_ust_context, node);
1227                 cds_list_del(&ctx->list);
1228                 /* Remove from channel's hash table. */
1229                 ret = lttng_ht_del(ht, &iter);
1230                 if (!ret) {
1231                         call_rcu(&node->head, destroy_context_rcu);
1232                 }
1233         }
1234         rcu_read_unlock();
1235
1236         lttng_ht_destroy(ht);
1237 }
1238
1239 /*
1240  * Cleanup ust event structure.
1241  */
1242 void trace_ust_destroy_event(struct ltt_ust_event *event)
1243 {
1244         LTTNG_ASSERT(event);
1245
1246         DBG2("Trace destroy UST event %s", event->attr.name);
1247         free(event->filter_expression);
1248         free(event->filter);
1249         free(event->exclusion);
1250         free(event);
1251 }
1252
1253 /*
1254  * Cleanup ust context structure.
1255  */
1256 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1257 {
1258         LTTNG_ASSERT(ctx);
1259
1260         if (ctx->ctx.ctx == LTTNG_UST_ABI_CONTEXT_APP_CONTEXT) {
1261                 free(ctx->ctx.u.app_ctx.provider_name);
1262                 free(ctx->ctx.u.app_ctx.ctx_name);
1263         }
1264         free(ctx);
1265 }
1266
1267 /*
1268  * URCU intermediate call to complete destroy event.
1269  */
1270 static void destroy_event_rcu(struct rcu_head *head)
1271 {
1272         struct lttng_ht_node_str *node =
1273                 caa_container_of(head, struct lttng_ht_node_str, head);
1274         struct ltt_ust_event *event =
1275                 caa_container_of(node, struct ltt_ust_event, node);
1276
1277         trace_ust_destroy_event(event);
1278 }
1279
1280 /*
1281  * Cleanup UST events hashtable.
1282  */
1283 static void destroy_events(struct lttng_ht *events)
1284 {
1285         int ret;
1286         struct lttng_ht_node_str *node;
1287         struct lttng_ht_iter iter;
1288
1289         LTTNG_ASSERT(events);
1290
1291         rcu_read_lock();
1292         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1293                 ret = lttng_ht_del(events, &iter);
1294                 LTTNG_ASSERT(!ret);
1295                 call_rcu(&node->head, destroy_event_rcu);
1296         }
1297         rcu_read_unlock();
1298
1299         lttng_ht_destroy(events);
1300 }
1301
1302 /*
1303  * Cleanup ust channel structure.
1304  *
1305  * Should _NOT_ be called with RCU read lock held.
1306  */
1307 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1308 {
1309         LTTNG_ASSERT(channel);
1310
1311         DBG2("Trace destroy UST channel %s", channel->name);
1312
1313         free(channel);
1314 }
1315
1316 /*
1317  * URCU intermediate call to complete destroy channel.
1318  */
1319 static void destroy_channel_rcu(struct rcu_head *head)
1320 {
1321         struct lttng_ht_node_str *node =
1322                 caa_container_of(head, struct lttng_ht_node_str, head);
1323         struct ltt_ust_channel *channel =
1324                 caa_container_of(node, struct ltt_ust_channel, node);
1325
1326         _trace_ust_destroy_channel(channel);
1327 }
1328
1329 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1330 {
1331         /* Destroying all events of the channel */
1332         destroy_events(channel->events);
1333         /* Destroying all context of the channel */
1334         destroy_contexts(channel->ctx);
1335
1336         call_rcu(&channel->node.head, destroy_channel_rcu);
1337 }
1338
1339 /*
1340  * Remove an UST channel from a channel HT.
1341  */
1342 void trace_ust_delete_channel(struct lttng_ht *ht,
1343                 struct ltt_ust_channel *channel)
1344 {
1345         int ret;
1346         struct lttng_ht_iter iter;
1347
1348         LTTNG_ASSERT(ht);
1349         LTTNG_ASSERT(channel);
1350
1351         iter.iter.node = &channel->node.node;
1352         ret = lttng_ht_del(ht, &iter);
1353         LTTNG_ASSERT(!ret);
1354 }
1355
1356 /*
1357  * Iterate over a hash table containing channels and cleanup safely.
1358  */
1359 static void destroy_channels(struct lttng_ht *channels)
1360 {
1361         struct lttng_ht_node_str *node;
1362         struct lttng_ht_iter iter;
1363
1364         LTTNG_ASSERT(channels);
1365
1366         rcu_read_lock();
1367         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1368                 struct ltt_ust_channel *chan =
1369                         caa_container_of(node, struct ltt_ust_channel, node);
1370
1371                 trace_ust_delete_channel(channels, chan);
1372                 trace_ust_destroy_channel(chan);
1373         }
1374         rcu_read_unlock();
1375
1376         lttng_ht_destroy(channels);
1377 }
1378
1379 /*
1380  * Cleanup UST global domain.
1381  */
1382 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1383 {
1384         LTTNG_ASSERT(dom);
1385
1386         destroy_channels(dom->channels);
1387 }
1388
1389 /*
1390  * Cleanup ust session structure, keeping data required by
1391  * destroy notifier.
1392  */
1393 void trace_ust_destroy_session(struct ltt_ust_session *session)
1394 {
1395         struct agent *agt;
1396         struct buffer_reg_uid *reg, *sreg;
1397         struct lttng_ht_iter iter;
1398
1399         LTTNG_ASSERT(session);
1400
1401         DBG2("Trace UST destroy session %" PRIu64, session->id);
1402
1403         /* Cleaning up UST domain */
1404         destroy_domain_global(&session->domain_global);
1405
1406         rcu_read_lock();
1407         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1408                 int ret = lttng_ht_del(session->agents, &iter);
1409
1410                 LTTNG_ASSERT(!ret);
1411                 agent_destroy(agt);
1412         }
1413         rcu_read_unlock();
1414
1415         lttng_ht_destroy(session->agents);
1416
1417         /* Cleanup UID buffer registry object(s). */
1418         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1419                         lnode) {
1420                 cds_list_del(&reg->lnode);
1421                 buffer_reg_uid_remove(reg);
1422                 buffer_reg_uid_destroy(reg, session->consumer);
1423         }
1424
1425         process_attr_tracker_destroy(session->tracker_vpid);
1426         process_attr_tracker_destroy(session->tracker_vuid);
1427         process_attr_tracker_destroy(session->tracker_vgid);
1428
1429         fini_id_tracker(&session->vpid_tracker);
1430         fini_id_tracker(&session->vuid_tracker);
1431         fini_id_tracker(&session->vgid_tracker);
1432         lttng_trace_chunk_put(session->current_trace_chunk);
1433 }
1434
1435 /* Free elements needed by destroy notifiers. */
1436 void trace_ust_free_session(struct ltt_ust_session *session)
1437 {
1438         consumer_output_put(session->consumer);
1439         free(session);
1440 }