liblttng-ust/lttng-events.c

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * Holds LTTng per-session event registry.
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <stdio.h>
  11 #include <assert.h>
  12 #include <errno.h>
  13 #include <limits.h>
  14 #include <pthread.h>
  15 #include <sys/shm.h>
  16 #include <sys/ipc.h>
  17 #include <stdint.h>
  18 #include <stddef.h>
  19 #include <inttypes.h>
  20 #include <time.h>
  21 #include <stdbool.h>
  22 #include <unistd.h>
  23 #include <dlfcn.h>
  24 #include <lttng/ust-endian.h>
  25
  26 #include <urcu/arch.h>
  27 #include <urcu/compiler.h>
  28 #include <urcu/hlist.h>
  29 #include <urcu/list.h>
  30 #include <urcu/uatomic.h>
  31
  32 #include <lttng/tracepoint.h>
  33 #include <lttng/ust-events.h>
  34
  35 #include <usterr-signal-safe.h>
  36 #include <ust-helper.h>
  37 #include <lttng/ust-ctl.h>
  38 #include <ust-comm.h>
  39 #include <ust-fd.h>
  40 #include <ust-dynamic-type.h>
  41 #include <ust-context-provider.h>
  42 #include "error.h"
  43 #include "compat.h"
  44 #include "lttng-ust-uuid.h"
  45
  46 #include "tracepoint-internal.h"
  47 #include "string-utils.h"
  48 #include "lttng-bytecode.h"
  49 #include "lttng-tracer.h"
  50 #include "lttng-tracer-core.h"
  51 #include "lttng-ust-statedump.h"
  52 #include "context-internal.h"
  53 #include "ust-events-internal.h"
  54 #include "wait.h"
  55 #include "../libringbuffer/shm.h"
  56 #include "../libcounter/counter.h"
  57 #include "jhash.h"
  58 #include <lttng/ust-abi.h>
  59
  60 /*
  61  * All operations within this file are called by the communication
  62  * thread, under ust_lock protection.
  63  */
  64
  65 static CDS_LIST_HEAD(sessions);
  66 static CDS_LIST_HEAD(event_notifier_groups);
  67
  68 struct cds_list_head *lttng_get_sessions(void)
  69 {
  70         return &sessions;
  71 }
  72
  73 static void _lttng_event_destroy(struct lttng_ust_event_common *event);
  74 static void _lttng_enum_destroy(struct lttng_enum *_enum);
  75
  76 static
  77 void lttng_session_lazy_sync_event_enablers(struct lttng_ust_session *session);
  78 static
  79 void lttng_session_sync_event_enablers(struct lttng_ust_session *session);
  80 static
  81 void lttng_event_notifier_group_sync_enablers(
  82                 struct lttng_event_notifier_group *event_notifier_group);
  83 static
  84 void lttng_enabler_destroy(struct lttng_enabler *enabler);
  85
  86 /*
  87  * Called with ust lock held.
  88  */
  89 int lttng_session_active(void)
  90 {
  91         struct lttng_ust_session_private *iter;
  92
  93         cds_list_for_each_entry(iter, &sessions, node) {
  94                 if (iter->pub->active)
  95                         return 1;
  96         }
  97         return 0;
  98 }
  99
 100 static
 101 int lttng_loglevel_match(int loglevel,
 102                 unsigned int has_loglevel,
 103                 enum lttng_ust_abi_loglevel_type req_type,
 104                 int req_loglevel)
 105 {
 106         if (!has_loglevel)
 107                 loglevel = TRACE_DEFAULT;
 108         switch (req_type) {
 109         case LTTNG_UST_ABI_LOGLEVEL_RANGE:
 110                 if (loglevel <= req_loglevel
 111                                 || (req_loglevel == -1 && loglevel <= TRACE_DEBUG))
 112                         return 1;
 113                 else
 114                         return 0;
 115         case LTTNG_UST_ABI_LOGLEVEL_SINGLE:
 116                 if (loglevel == req_loglevel
 117                                 || (req_loglevel == -1 && loglevel <= TRACE_DEBUG))
 118                         return 1;
 119                 else
 120                         return 0;
 121         case LTTNG_UST_ABI_LOGLEVEL_ALL:
 122         default:
 123                 if (loglevel <= TRACE_DEBUG)
 124                         return 1;
 125                 else
 126                         return 0;
 127         }
 128 }
 129
 130 struct lttng_ust_session *lttng_session_create(void)
 131 {
 132         struct lttng_ust_session *session;
 133         struct lttng_ust_session_private *session_priv;
 134         int i;
 135
 136         session = zmalloc(sizeof(struct lttng_ust_session));
 137         if (!session)
 138                 return NULL;
 139         session->struct_size = sizeof(struct lttng_ust_session);
 140         session_priv = zmalloc(sizeof(struct lttng_ust_session_private));
 141         if (!session_priv) {
 142                 free(session);
 143                 return NULL;
 144         }
 145         session->priv = session_priv;
 146         session_priv->pub = session;
 147         if (lttng_context_init_all(&session->priv->ctx)) {
 148                 free(session_priv);
 149                 free(session);
 150                 return NULL;
 151         }
 152         CDS_INIT_LIST_HEAD(&session->priv->chan_head);
 153         CDS_INIT_LIST_HEAD(&session->priv->events_head);
 154         CDS_INIT_LIST_HEAD(&session->priv->enums_head);
 155         CDS_INIT_LIST_HEAD(&session->priv->enablers_head);
 156         for (i = 0; i < LTTNG_UST_EVENT_HT_SIZE; i++)
 157                 CDS_INIT_HLIST_HEAD(&session->priv->events_ht.table[i]);
 158         for (i = 0; i < LTTNG_UST_ENUM_HT_SIZE; i++)
 159                 CDS_INIT_HLIST_HEAD(&session->priv->enums_ht.table[i]);
 160         cds_list_add(&session->priv->node, &sessions);
 161         return session;
 162 }
 163
 164 struct lttng_counter *lttng_ust_counter_create(
 165                 const char *counter_transport_name,
 166                 size_t number_dimensions, const struct lttng_counter_dimension *dimensions)
 167 {
 168         struct lttng_counter_transport *counter_transport = NULL;
 169         struct lttng_counter *counter = NULL;
 170
 171         counter_transport = lttng_counter_transport_find(counter_transport_name);
 172         if (!counter_transport)
 173                 goto notransport;
 174         counter = zmalloc(sizeof(struct lttng_counter));
 175         if (!counter)
 176                 goto nomem;
 177
 178         counter->ops = &counter_transport->ops;
 179         counter->transport = counter_transport;
 180
 181         counter->counter = counter->ops->counter_create(
 182                         number_dimensions, dimensions, 0,
 183                         -1, 0, NULL, false);
 184         if (!counter->counter) {
 185                 goto create_error;
 186         }
 187
 188         return counter;
 189
 190 create_error:
 191         free(counter);
 192 nomem:
 193 notransport:
 194         return NULL;
 195 }
 196
 197 static
 198 void lttng_ust_counter_destroy(struct lttng_counter *counter)
 199 {
 200         counter->ops->counter_destroy(counter->counter);
 201         free(counter);
 202 }
 203
 204 struct lttng_event_notifier_group *lttng_event_notifier_group_create(void)
 205 {
 206         struct lttng_event_notifier_group *event_notifier_group;
 207         int i;
 208
 209         event_notifier_group = zmalloc(sizeof(struct lttng_event_notifier_group));
 210         if (!event_notifier_group)
 211                 return NULL;
 212
 213         /* Add all contexts. */
 214         if (lttng_context_init_all(&event_notifier_group->ctx)) {
 215                 free(event_notifier_group);
 216                 return NULL;
 217         }
 218
 219         CDS_INIT_LIST_HEAD(&event_notifier_group->enablers_head);
 220         CDS_INIT_LIST_HEAD(&event_notifier_group->event_notifiers_head);
 221         for (i = 0; i < LTTNG_UST_EVENT_NOTIFIER_HT_SIZE; i++)
 222                 CDS_INIT_HLIST_HEAD(&event_notifier_group->event_notifiers_ht.table[i]);
 223
 224         cds_list_add(&event_notifier_group->node, &event_notifier_groups);
 225
 226         return event_notifier_group;
 227 }
 228
 229 /*
 230  * Only used internally at session destruction.
 231  */
 232 static
 233 void _lttng_channel_unmap(struct lttng_channel *lttng_chan)
 234 {
 235         struct lttng_ust_lib_ring_buffer_channel *chan;
 236         struct lttng_ust_shm_handle *handle;
 237
 238         cds_list_del(&lttng_chan->node);
 239         lttng_destroy_context(lttng_chan->ctx);
 240         chan = lttng_chan->chan;
 241         handle = lttng_chan->handle;
 242         channel_destroy(chan, handle, 0);
 243         free(lttng_chan);
 244 }
 245
 246 static
 247 void register_event(struct lttng_ust_event_common *event)
 248 {
 249         int ret;
 250         struct lttng_ust_event_desc *desc;
 251
 252         assert(event->priv->registered == 0);
 253         desc = event->priv->desc;
 254         ret = lttng_ust_tp_probe_register_queue_release(desc->name,
 255                         desc->probe_callback,
 256                         event, desc->signature);
 257         WARN_ON_ONCE(ret);
 258         if (!ret)
 259                 event->priv->registered = 1;
 260 }
 261
 262 static
 263 void unregister_event(struct lttng_ust_event_common *event)
 264 {
 265         int ret;
 266         struct lttng_ust_event_desc *desc;
 267
 268         assert(event->priv->registered == 1);
 269         desc = event->priv->desc;
 270         ret = lttng_ust_tp_probe_unregister_queue_release(desc->name,
 271                         desc->probe_callback,
 272                         event);
 273         WARN_ON_ONCE(ret);
 274         if (!ret)
 275                 event->priv->registered = 0;
 276 }
 277
 278 static
 279 void _lttng_event_unregister(struct lttng_ust_event_common *event)
 280 {
 281         if (event->priv->registered)
 282                 unregister_event(event);
 283 }
 284
 285 void lttng_session_destroy(struct lttng_ust_session *session)
 286 {
 287         struct lttng_channel *chan, *tmpchan;
 288         struct lttng_ust_event_recorder_private *event_recorder_priv, *tmpevent_recorder_priv;
 289         struct lttng_enum *_enum, *tmp_enum;
 290         struct lttng_event_enabler *event_enabler, *event_tmpenabler;
 291
 292         CMM_ACCESS_ONCE(session->active) = 0;
 293         cds_list_for_each_entry(event_recorder_priv, &session->priv->events_head, node) {
 294                 _lttng_event_unregister(event_recorder_priv->parent.pub);
 295         }
 296         lttng_ust_urcu_synchronize_rcu();       /* Wait for in-flight events to complete */
 297         lttng_ust_tp_probe_prune_release_queue();
 298         cds_list_for_each_entry_safe(event_enabler, event_tmpenabler,
 299                         &session->priv->enablers_head, node)
 300                 lttng_event_enabler_destroy(event_enabler);
 301         cds_list_for_each_entry_safe(event_recorder_priv, tmpevent_recorder_priv,
 302                         &session->priv->events_head, node)
 303                 _lttng_event_destroy(event_recorder_priv->parent.pub);
 304         cds_list_for_each_entry_safe(_enum, tmp_enum,
 305                         &session->priv->enums_head, node)
 306                 _lttng_enum_destroy(_enum);
 307         cds_list_for_each_entry_safe(chan, tmpchan, &session->priv->chan_head, node)
 308                 _lttng_channel_unmap(chan);
 309         cds_list_del(&session->priv->node);
 310         lttng_destroy_context(session->priv->ctx);
 311         free(session->priv);
 312         free(session);
 313 }
 314
 315 void lttng_event_notifier_group_destroy(
 316                 struct lttng_event_notifier_group *event_notifier_group)
 317 {
 318         int close_ret;
 319         struct lttng_event_notifier_enabler *notifier_enabler, *tmpnotifier_enabler;
 320         struct lttng_ust_event_notifier_private *event_notifier_priv, *tmpevent_notifier_priv;
 321
 322         if (!event_notifier_group) {
 323                 return;
 324         }
 325
 326         cds_list_for_each_entry(event_notifier_priv,
 327                         &event_notifier_group->event_notifiers_head, node)
 328                 _lttng_event_unregister(event_notifier_priv->parent.pub);
 329
 330         lttng_ust_urcu_synchronize_rcu();
 331
 332         cds_list_for_each_entry_safe(notifier_enabler, tmpnotifier_enabler,
 333                         &event_notifier_group->enablers_head, node)
 334                 lttng_event_notifier_enabler_destroy(notifier_enabler);
 335
 336         cds_list_for_each_entry_safe(event_notifier_priv, tmpevent_notifier_priv,
 337                         &event_notifier_group->event_notifiers_head, node)
 338                 _lttng_event_destroy(event_notifier_priv->parent.pub);
 339
 340         if (event_notifier_group->error_counter)
 341                 lttng_ust_counter_destroy(event_notifier_group->error_counter);
 342
 343         /* Close the notification fd to the listener of event_notifiers. */
 344
 345         lttng_ust_lock_fd_tracker();
 346         close_ret = close(event_notifier_group->notification_fd);
 347         if (!close_ret) {
 348                 lttng_ust_delete_fd_from_tracker(
 349                                 event_notifier_group->notification_fd);
 350         } else {
 351                 PERROR("close");
 352                 abort();
 353         }
 354         lttng_ust_unlock_fd_tracker();
 355
 356         cds_list_del(&event_notifier_group->node);
 357
 358         free(event_notifier_group);
 359 }
 360
 361 static
 362 void lttng_enabler_destroy(struct lttng_enabler *enabler)
 363 {
 364         struct lttng_ust_bytecode_node *filter_node, *tmp_filter_node;
 365         struct lttng_ust_excluder_node *excluder_node, *tmp_excluder_node;
 366
 367         if (!enabler) {
 368                 return;
 369         }
 370
 371         /* Destroy filter bytecode */
 372         cds_list_for_each_entry_safe(filter_node, tmp_filter_node,
 373                         &enabler->filter_bytecode_head, node) {
 374                 free(filter_node);
 375         }
 376
 377         /* Destroy excluders */
 378         cds_list_for_each_entry_safe(excluder_node, tmp_excluder_node,
 379                         &enabler->excluder_head, node) {
 380                 free(excluder_node);
 381         }
 382 }
 383
 384  void lttng_event_notifier_enabler_destroy(struct lttng_event_notifier_enabler *event_notifier_enabler)
 385 {
 386         if (!event_notifier_enabler) {
 387                 return;
 388         }
 389
 390         cds_list_del(&event_notifier_enabler->node);
 391
 392         lttng_enabler_destroy(lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
 393
 394         free(event_notifier_enabler);
 395 }
 396
 397 static
 398 int lttng_enum_create(struct lttng_ust_enum_desc *desc,
 399                 struct lttng_ust_session *session)
 400 {
 401         const char *enum_name = desc->name;
 402         struct lttng_enum *_enum;
 403         struct cds_hlist_head *head;
 404         int ret = 0;
 405         size_t name_len = strlen(enum_name);
 406         uint32_t hash;
 407         int notify_socket;
 408
 409         /* Check if this enum is already registered for this session. */
 410         hash = jhash(enum_name, name_len, 0);
 411         head = &session->priv->enums_ht.table[hash & (LTTNG_UST_ENUM_HT_SIZE - 1)];
 412
 413         _enum = lttng_ust_enum_get_from_desc(session, desc);
 414         if (_enum) {
 415                 ret = -EEXIST;
 416                 goto exist;
 417         }
 418
 419         notify_socket = lttng_get_notify_socket(session->priv->owner);
 420         if (notify_socket < 0) {
 421                 ret = notify_socket;
 422                 goto socket_error;
 423         }
 424
 425         _enum = zmalloc(sizeof(*_enum));
 426         if (!_enum) {
 427                 ret = -ENOMEM;
 428                 goto cache_error;
 429         }
 430         _enum->session = session;
 431         _enum->desc = desc;
 432
 433         ret = ustcomm_register_enum(notify_socket,
 434                 session->priv->objd,
 435                 enum_name,
 436                 desc->nr_entries,
 437                 desc->entries,
 438                 &_enum->id);
 439         if (ret < 0) {
 440                 DBG("Error (%d) registering enumeration to sessiond", ret);
 441                 goto sessiond_register_error;
 442         }
 443         cds_list_add(&_enum->node, &session->priv->enums_head);
 444         cds_hlist_add_head(&_enum->hlist, head);
 445         return 0;
 446
 447 sessiond_register_error:
 448         free(_enum);
 449 cache_error:
 450 socket_error:
 451 exist:
 452         return ret;
 453 }
 454
 455 static
 456 int lttng_create_enum_check(struct lttng_ust_type_common *type,
 457                 struct lttng_ust_session *session)
 458 {
 459         switch (type->type) {
 460         case lttng_ust_type_enum:
 461         {
 462                 struct lttng_ust_enum_desc *enum_desc;
 463                 int ret;
 464
 465                 enum_desc = lttng_ust_get_type_enum(type)->desc;
 466                 ret = lttng_enum_create(enum_desc, session);
 467                 if (ret && ret != -EEXIST) {
 468                         DBG("Unable to create enum error: (%d)", ret);
 469                         return ret;
 470                 }
 471                 break;
 472         }
 473         case lttng_ust_type_dynamic:
 474         {
 475                 struct lttng_ust_event_field *tag_field_generic;
 476                 struct lttng_ust_enum_desc *enum_desc;
 477                 int ret;
 478
 479                 tag_field_generic = lttng_ust_dynamic_type_tag_field();
 480                 enum_desc = lttng_ust_get_type_enum(tag_field_generic->type)->desc;
 481                 ret = lttng_enum_create(enum_desc, session);
 482                 if (ret && ret != -EEXIST) {
 483                         DBG("Unable to create enum error: (%d)", ret);
 484                         return ret;
 485                 }
 486                 break;
 487         }
 488         default:
 489                 /* TODO: nested types when they become supported. */
 490                 break;
 491         }
 492         return 0;
 493 }
 494
 495 static
 496 int lttng_create_all_event_enums(size_t nr_fields,
 497                 struct lttng_ust_event_field **event_fields,
 498                 struct lttng_ust_session *session)
 499 {
 500         size_t i;
 501         int ret;
 502
 503         /* For each field, ensure enum is part of the session. */
 504         for (i = 0; i < nr_fields; i++) {
 505                 struct lttng_ust_type_common *type = event_fields[i]->type;
 506
 507                 ret = lttng_create_enum_check(type, session);
 508                 if (ret)
 509                         return ret;
 510         }
 511         return 0;
 512 }
 513
 514 static
 515 int lttng_create_all_ctx_enums(size_t nr_fields,
 516                 struct lttng_ust_ctx_field **ctx_fields,
 517                 struct lttng_ust_session *session)
 518 {
 519         size_t i;
 520         int ret;
 521
 522         /* For each field, ensure enum is part of the session. */
 523         for (i = 0; i < nr_fields; i++) {
 524                 struct lttng_ust_type_common *type = ctx_fields[i]->event_field->type;
 525
 526                 ret = lttng_create_enum_check(type, session);
 527                 if (ret)
 528                         return ret;
 529         }
 530         return 0;
 531 }
 532
 533 /*
 534  * Ensure that a state-dump will be performed for this session at the end
 535  * of the current handle_message().
 536  */
 537 int lttng_session_statedump(struct lttng_ust_session *session)
 538 {
 539         session->priv->statedump_pending = 1;
 540         lttng_ust_sockinfo_session_enabled(session->priv->owner);
 541         return 0;
 542 }
 543
 544 int lttng_session_enable(struct lttng_ust_session *session)
 545 {
 546         int ret = 0;
 547         struct lttng_channel *chan;
 548         int notify_socket;
 549
 550         if (session->active) {
 551                 ret = -EBUSY;
 552                 goto end;
 553         }
 554
 555         notify_socket = lttng_get_notify_socket(session->priv->owner);
 556         if (notify_socket < 0)
 557                 return notify_socket;
 558
 559         /* Set transient enabler state to "enabled" */
 560         session->priv->tstate = 1;
 561
 562         /* We need to sync enablers with session before activation. */
 563         lttng_session_sync_event_enablers(session);
 564
 565         /*
 566          * Snapshot the number of events per channel to know the type of header
 567          * we need to use.
 568          */
 569         cds_list_for_each_entry(chan, &session->priv->chan_head, node) {
 570                 struct lttng_ust_ctx *ctx;
 571                 struct lttng_ust_ctx_field **fields = NULL;
 572                 size_t nr_fields = 0;
 573                 uint32_t chan_id;
 574
 575                 /* don't change it if session stop/restart */
 576                 if (chan->header_type)
 577                         continue;
 578                 ctx = chan->ctx;
 579                 if (ctx) {
 580                         nr_fields = ctx->nr_fields;
 581                         fields = ctx->fields;
 582                         ret = lttng_create_all_ctx_enums(nr_fields, fields,
 583                                 session);
 584                         if (ret < 0) {
 585                                 DBG("Error (%d) adding enum to session", ret);
 586                                 return ret;
 587                         }
 588                 }
 589                 ret = ustcomm_register_channel(notify_socket,
 590                         session,
 591                         session->priv->objd,
 592                         chan->objd,
 593                         nr_fields,
 594                         fields,
 595                         &chan_id,
 596                         &chan->header_type);
 597                 if (ret) {
 598                         DBG("Error (%d) registering channel to sessiond", ret);
 599                         return ret;
 600                 }
 601                 if (chan_id != chan->id) {
 602                         DBG("Error: channel registration id (%u) does not match id assigned at creation (%u)",
 603                                 chan_id, chan->id);
 604                         return -EINVAL;
 605                 }
 606         }
 607
 608         /* Set atomically the state to "active" */
 609         CMM_ACCESS_ONCE(session->active) = 1;
 610         CMM_ACCESS_ONCE(session->priv->been_active) = 1;
 611
 612         ret = lttng_session_statedump(session);
 613         if (ret)
 614                 return ret;
 615 end:
 616         return ret;
 617 }
 618
 619 int lttng_session_disable(struct lttng_ust_session *session)
 620 {
 621         int ret = 0;
 622
 623         if (!session->active) {
 624                 ret = -EBUSY;
 625                 goto end;
 626         }
 627         /* Set atomically the state to "inactive" */
 628         CMM_ACCESS_ONCE(session->active) = 0;
 629
 630         /* Set transient enabler state to "disabled" */
 631         session->priv->tstate = 0;
 632         lttng_session_sync_event_enablers(session);
 633 end:
 634         return ret;
 635 }
 636
 637 int lttng_channel_enable(struct lttng_channel *channel)
 638 {
 639         int ret = 0;
 640
 641         if (channel->enabled) {
 642                 ret = -EBUSY;
 643                 goto end;
 644         }
 645         /* Set transient enabler state to "enabled" */
 646         channel->tstate = 1;
 647         lttng_session_sync_event_enablers(channel->session);
 648         /* Set atomically the state to "enabled" */
 649         CMM_ACCESS_ONCE(channel->enabled) = 1;
 650 end:
 651         return ret;
 652 }
 653
 654 int lttng_channel_disable(struct lttng_channel *channel)
 655 {
 656         int ret = 0;
 657
 658         if (!channel->enabled) {
 659                 ret = -EBUSY;
 660                 goto end;
 661         }
 662         /* Set atomically the state to "disabled" */
 663         CMM_ACCESS_ONCE(channel->enabled) = 0;
 664         /* Set transient enabler state to "enabled" */
 665         channel->tstate = 0;
 666         lttng_session_sync_event_enablers(channel->session);
 667 end:
 668         return ret;
 669 }
 670
 671 static inline
 672 struct cds_hlist_head *borrow_hash_table_bucket(
 673                 struct cds_hlist_head *hash_table,
 674                 unsigned int hash_table_size,
 675                 struct lttng_ust_event_desc *desc)
 676 {
 677         const char *event_name;
 678         size_t name_len;
 679         uint32_t hash;
 680
 681         event_name = desc->name;
 682         name_len = strlen(event_name);
 683
 684         hash = jhash(event_name, name_len, 0);
 685         return &hash_table[hash & (hash_table_size - 1)];
 686 }
 687
 688 /*
 689  * Supports event creation while tracing session is active.
 690  */
 691 static
 692 int lttng_event_recorder_create(struct lttng_ust_event_desc *desc,
 693                 struct lttng_channel *chan)
 694 {
 695         struct lttng_ust_event_recorder *event_recorder;
 696         struct lttng_ust_event_recorder_private *event_recorder_priv;
 697         struct lttng_ust_session *session = chan->session;
 698         struct cds_hlist_head *head;
 699         int ret = 0;
 700         int notify_socket, loglevel;
 701         const char *uri;
 702
 703         head = borrow_hash_table_bucket(chan->session->priv->events_ht.table,
 704                 LTTNG_UST_EVENT_HT_SIZE, desc);
 705
 706         notify_socket = lttng_get_notify_socket(session->priv->owner);
 707         if (notify_socket < 0) {
 708                 ret = notify_socket;
 709                 goto socket_error;
 710         }
 711
 712         ret = lttng_create_all_event_enums(desc->nr_fields, desc->fields,
 713                         session);
 714         if (ret < 0) {
 715                 DBG("Error (%d) adding enum to session", ret);
 716                 goto create_enum_error;
 717         }
 718
 719         /*
 720          * Check if loglevel match. Refuse to connect event if not.
 721          */
 722         event_recorder = zmalloc(sizeof(struct lttng_ust_event_recorder));
 723         if (!event_recorder) {
 724                 ret = -ENOMEM;
 725                 goto cache_error;
 726         }
 727         event_recorder->struct_size = sizeof(struct lttng_ust_event_recorder);
 728
 729         event_recorder->parent = zmalloc(sizeof(struct lttng_ust_event_common));
 730         if (!event_recorder->parent) {
 731                 ret = -ENOMEM;
 732                 goto parent_error;
 733         }
 734         event_recorder->parent->struct_size = sizeof(struct lttng_ust_event_common);
 735         event_recorder->parent->type = LTTNG_UST_EVENT_TYPE_RECORDER;
 736         event_recorder->parent->child = event_recorder;
 737
 738         event_recorder_priv = zmalloc(sizeof(struct lttng_ust_event_recorder_private));
 739         if (!event_recorder_priv) {
 740                 ret = -ENOMEM;
 741                 goto priv_error;
 742         }
 743         event_recorder->priv = event_recorder_priv;
 744         event_recorder_priv->pub = event_recorder;
 745         event_recorder->parent->priv = &event_recorder_priv->parent;
 746         event_recorder_priv->parent.pub = event_recorder->parent;
 747
 748         event_recorder->chan = chan;
 749
 750         /* Event will be enabled by enabler sync. */
 751         event_recorder->parent->enabled = 0;
 752         event_recorder->parent->priv->registered = 0;
 753         CDS_INIT_LIST_HEAD(&event_recorder->parent->filter_bytecode_runtime_head);
 754         CDS_INIT_LIST_HEAD(&event_recorder->parent->priv->enablers_ref_head);
 755         event_recorder->parent->priv->desc = desc;
 756
 757         if (desc->loglevel)
 758                 loglevel = *(*event_recorder->parent->priv->desc->loglevel);
 759         else
 760                 loglevel = TRACE_DEFAULT;
 761         if (desc->model_emf_uri)
 762                 uri = *(desc->model_emf_uri);
 763         else
 764                 uri = NULL;
 765
 766         /* Fetch event ID from sessiond */
 767         ret = ustcomm_register_event(notify_socket,
 768                 session,
 769                 session->priv->objd,
 770                 chan->objd,
 771                 desc->name,
 772                 loglevel,
 773                 desc->signature,
 774                 desc->nr_fields,
 775                 desc->fields,
 776                 uri,
 777                 &event_recorder->id);
 778         if (ret < 0) {
 779                 DBG("Error (%d) registering event to sessiond", ret);
 780                 goto sessiond_register_error;
 781         }
 782
 783         cds_list_add(&event_recorder_priv->node, &chan->session->priv->events_head);
 784         cds_hlist_add_head(&event_recorder_priv->hlist, head);
 785         return 0;
 786
 787 sessiond_register_error:
 788         free(event_recorder_priv);
 789 priv_error:
 790         free(event_recorder->parent);
 791 parent_error:
 792         free(event_recorder);
 793 cache_error:
 794 create_enum_error:
 795 socket_error:
 796         return ret;
 797 }
 798
 799 static
 800 int lttng_event_notifier_create(struct lttng_ust_event_desc *desc,
 801                 uint64_t token, uint64_t error_counter_index,
 802                 struct lttng_event_notifier_group *event_notifier_group)
 803 {
 804         struct lttng_ust_event_notifier *event_notifier;
 805         struct lttng_ust_event_notifier_private *event_notifier_priv;
 806         struct cds_hlist_head *head;
 807         int ret = 0;
 808
 809         /*
 810          * Get the hashtable bucket the created lttng_event_notifier object
 811          * should be inserted.
 812          */
 813         head = borrow_hash_table_bucket(
 814                 event_notifier_group->event_notifiers_ht.table,
 815                 LTTNG_UST_EVENT_NOTIFIER_HT_SIZE, desc);
 816
 817         event_notifier = zmalloc(sizeof(struct lttng_ust_event_notifier));
 818         if (!event_notifier) {
 819                 ret = -ENOMEM;
 820                 goto error;
 821         }
 822         event_notifier->struct_size = sizeof(struct lttng_ust_event_notifier);
 823
 824         event_notifier->parent = zmalloc(sizeof(struct lttng_ust_event_common));
 825         if (!event_notifier->parent) {
 826                 ret = -ENOMEM;
 827                 goto parent_error;
 828         }
 829         event_notifier->parent->struct_size = sizeof(struct lttng_ust_event_common);
 830         event_notifier->parent->type = LTTNG_UST_EVENT_TYPE_NOTIFIER;
 831         event_notifier->parent->child = event_notifier;
 832
 833         event_notifier_priv = zmalloc(sizeof(struct lttng_ust_event_notifier_private));
 834         if (!event_notifier_priv) {
 835                 ret = -ENOMEM;
 836                 goto priv_error;
 837         }
 838         event_notifier->priv = event_notifier_priv;
 839         event_notifier_priv->pub = event_notifier;
 840         event_notifier->parent->priv = &event_notifier_priv->parent;
 841         event_notifier_priv->parent.pub = event_notifier->parent;
 842
 843         event_notifier_priv->group = event_notifier_group;
 844         event_notifier_priv->parent.user_token = token;
 845         event_notifier_priv->error_counter_index = error_counter_index;
 846
 847         /* Event notifier will be enabled by enabler sync. */
 848         event_notifier->parent->enabled = 0;
 849         event_notifier_priv->parent.registered = 0;
 850
 851         CDS_INIT_LIST_HEAD(&event_notifier->parent->filter_bytecode_runtime_head);
 852         CDS_INIT_LIST_HEAD(&event_notifier->capture_bytecode_runtime_head);
 853         CDS_INIT_LIST_HEAD(&event_notifier_priv->parent.enablers_ref_head);
 854         event_notifier_priv->parent.desc = desc;
 855         event_notifier->notification_send = lttng_event_notifier_notification_send;
 856
 857         cds_list_add(&event_notifier_priv->node,
 858                         &event_notifier_group->event_notifiers_head);
 859         cds_hlist_add_head(&event_notifier_priv->hlist, head);
 860
 861         return 0;
 862
 863 priv_error:
 864         free(event_notifier->parent);
 865 parent_error:
 866         free(event_notifier);
 867 error:
 868         return ret;
 869 }
 870
 871 static
 872 int lttng_desc_match_star_glob_enabler(struct lttng_ust_event_desc *desc,
 873                 struct lttng_enabler *enabler)
 874 {
 875         int loglevel = 0;
 876         unsigned int has_loglevel = 0;
 877
 878         assert(enabler->format_type == LTTNG_ENABLER_FORMAT_STAR_GLOB);
 879         if (!strutils_star_glob_match(enabler->event_param.name, SIZE_MAX,
 880                         desc->name, SIZE_MAX))
 881                 return 0;
 882         if (desc->loglevel) {
 883                 loglevel = *(*desc->loglevel);
 884                 has_loglevel = 1;
 885         }
 886         if (!lttng_loglevel_match(loglevel,
 887                         has_loglevel,
 888                         enabler->event_param.loglevel_type,
 889                         enabler->event_param.loglevel))
 890                 return 0;
 891         return 1;
 892 }
 893
 894 static
 895 int lttng_desc_match_event_enabler(struct lttng_ust_event_desc *desc,
 896                 struct lttng_enabler *enabler)
 897 {
 898         int loglevel = 0;
 899         unsigned int has_loglevel = 0;
 900
 901         assert(enabler->format_type == LTTNG_ENABLER_FORMAT_EVENT);
 902         if (strcmp(desc->name, enabler->event_param.name))
 903                 return 0;
 904         if (desc->loglevel) {
 905                 loglevel = *(*desc->loglevel);
 906                 has_loglevel = 1;
 907         }
 908         if (!lttng_loglevel_match(loglevel,
 909                         has_loglevel,
 910                         enabler->event_param.loglevel_type,
 911                         enabler->event_param.loglevel))
 912                 return 0;
 913         return 1;
 914 }
 915
 916 static
 917 int lttng_desc_match_enabler(struct lttng_ust_event_desc *desc,
 918                 struct lttng_enabler *enabler)
 919 {
 920         switch (enabler->format_type) {
 921         case LTTNG_ENABLER_FORMAT_STAR_GLOB:
 922         {
 923                 struct lttng_ust_excluder_node *excluder;
 924
 925                 if (!lttng_desc_match_star_glob_enabler(desc, enabler)) {
 926                         return 0;
 927                 }
 928
 929                 /*
 930                  * If the matching event matches with an excluder,
 931                  * return 'does not match'
 932                  */
 933                 cds_list_for_each_entry(excluder, &enabler->excluder_head, node) {
 934                         int count;
 935
 936                         for (count = 0; count < excluder->excluder.count; count++) {
 937                                 int len;
 938                                 char *excluder_name;
 939
 940                                 excluder_name = (char *) (excluder->excluder.names)
 941                                                 + count * LTTNG_UST_ABI_SYM_NAME_LEN;
 942                                 len = strnlen(excluder_name, LTTNG_UST_ABI_SYM_NAME_LEN);
 943                                 if (len > 0 && strutils_star_glob_match(excluder_name, len, desc->name, SIZE_MAX))
 944                                         return 0;
 945                         }
 946                 }
 947                 return 1;
 948         }
 949         case LTTNG_ENABLER_FORMAT_EVENT:
 950                 return lttng_desc_match_event_enabler(desc, enabler);
 951         default:
 952                 return -EINVAL;
 953         }
 954 }
 955
 956 static
 957 int lttng_event_enabler_match_event(struct lttng_event_enabler *event_enabler,
 958                 struct lttng_ust_event_recorder *event_recorder)
 959 {
 960         if (lttng_desc_match_enabler(event_recorder->parent->priv->desc,
 961                         lttng_event_enabler_as_enabler(event_enabler))
 962                         && event_recorder->chan == event_enabler->chan)
 963                 return 1;
 964         else
 965                 return 0;
 966 }
 967
 968 static
 969 int lttng_event_notifier_enabler_match_event_notifier(
 970                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 971                 struct lttng_ust_event_notifier *event_notifier)
 972 {
 973         int desc_matches = lttng_desc_match_enabler(event_notifier->priv->parent.desc,
 974                 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
 975
 976         if (desc_matches && event_notifier->priv->group == event_notifier_enabler->group &&
 977                         event_notifier->priv->parent.user_token == event_notifier_enabler->user_token)
 978                 return 1;
 979         else
 980                 return 0;
 981 }
 982
 983 static
 984 struct lttng_enabler_ref *lttng_enabler_ref(
 985                 struct cds_list_head *enabler_ref_list,
 986                 struct lttng_enabler *enabler)
 987 {
 988         struct lttng_enabler_ref *enabler_ref;
 989
 990         cds_list_for_each_entry(enabler_ref, enabler_ref_list, node) {
 991                 if (enabler_ref->ref == enabler)
 992                         return enabler_ref;
 993         }
 994         return NULL;
 995 }
 996
 997 /*
 998  * Create struct lttng_event if it is missing and present in the list of
 999  * tracepoint probes.
1000  */
1001 static
1002 void lttng_create_event_recorder_if_missing(struct lttng_event_enabler *event_enabler)
1003 {
1004         struct lttng_ust_session *session = event_enabler->chan->session;
1005         struct lttng_ust_probe_desc *probe_desc;
1006         struct lttng_ust_event_desc *desc;
1007         struct lttng_ust_event_recorder_private *event_recorder_priv;
1008         int i;
1009         struct cds_list_head *probe_list;
1010
1011         probe_list = lttng_get_probe_list_head();
1012         /*
1013          * For each probe event, if we find that a probe event matches
1014          * our enabler, create an associated lttng_event if not
1015          * already present.
1016          */
1017         cds_list_for_each_entry(probe_desc, probe_list, head) {
1018                 for (i = 0; i < probe_desc->nr_events; i++) {
1019                         int ret;
1020                         bool found = false;
1021                         struct cds_hlist_head *head;
1022                         struct cds_hlist_node *node;
1023
1024                         desc = probe_desc->event_desc[i];
1025                         if (!lttng_desc_match_enabler(desc,
1026                                         lttng_event_enabler_as_enabler(event_enabler)))
1027                                 continue;
1028
1029                         head = borrow_hash_table_bucket(
1030                                 session->priv->events_ht.table,
1031                                 LTTNG_UST_EVENT_HT_SIZE, desc);
1032
1033                         cds_hlist_for_each_entry(event_recorder_priv, node, head, hlist) {
1034                                 if (event_recorder_priv->parent.desc == desc
1035                                                 && event_recorder_priv->pub->chan == event_enabler->chan) {
1036                                         found = true;
1037                                         break;
1038                                 }
1039                         }
1040                         if (found)
1041                                 continue;
1042
1043                         /*
1044                          * We need to create an event for this
1045                          * event probe.
1046                          */
1047                         ret = lttng_event_recorder_create(probe_desc->event_desc[i],
1048                                         event_enabler->chan);
1049                         if (ret) {
1050                                 DBG("Unable to create event %s, error %d\n",
1051                                         probe_desc->event_desc[i]->name, ret);
1052                         }
1053                 }
1054         }
1055 }
1056
1057 static
1058 void probe_provider_event_for_each(struct lttng_ust_probe_desc *provider_desc,
1059                 void (*event_func)(struct lttng_ust_event_common *event))
1060 {
1061         struct cds_hlist_node *node, *tmp_node;
1062         struct cds_list_head *sessionsp;
1063         unsigned int i;
1064
1065         /* Get handle on list of sessions. */
1066         sessionsp = lttng_get_sessions();
1067
1068         /*
1069          * Iterate over all events in the probe provider descriptions and
1070          * sessions to queue the unregistration of the events.
1071          */
1072         for (i = 0; i < provider_desc->nr_events; i++) {
1073                 struct lttng_ust_event_desc *event_desc;
1074                 struct lttng_event_notifier_group *event_notifier_group;
1075                 struct lttng_ust_event_recorder_private *event_recorder_priv;
1076                 struct lttng_ust_event_notifier_private *event_notifier_priv;
1077                 struct lttng_ust_session_private *session_priv;
1078                 struct cds_hlist_head *head;
1079
1080                 event_desc = provider_desc->event_desc[i];
1081
1082                 /*
1083                  * Iterate over all session to find the current event
1084                  * description.
1085                  */
1086                 cds_list_for_each_entry(session_priv, sessionsp, node) {
1087                         /*
1088                          * Get the list of events in the hashtable bucket and
1089                          * iterate to find the event matching this descriptor.
1090                          */
1091                         head = borrow_hash_table_bucket(
1092                                 session_priv->events_ht.table,
1093                                 LTTNG_UST_EVENT_HT_SIZE, event_desc);
1094
1095                         cds_hlist_for_each_entry_safe(event_recorder_priv, node, tmp_node, head, hlist) {
1096                                 if (event_desc == event_recorder_priv->parent.desc) {
1097                                         event_func(event_recorder_priv->parent.pub);
1098                                         break;
1099                                 }
1100                         }
1101                 }
1102
1103                 /*
1104                  * Iterate over all event_notifier groups to find the current event
1105                  * description.
1106                  */
1107                 cds_list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
1108                         /*
1109                          * Get the list of event_notifiers in the hashtable bucket and
1110                          * iterate to find the event_notifier matching this
1111                          * descriptor.
1112                          */
1113                         head = borrow_hash_table_bucket(
1114                                 event_notifier_group->event_notifiers_ht.table,
1115                                 LTTNG_UST_EVENT_NOTIFIER_HT_SIZE, event_desc);
1116
1117                         cds_hlist_for_each_entry_safe(event_notifier_priv, node, tmp_node, head, hlist) {
1118                                 if (event_desc == event_notifier_priv->parent.desc) {
1119                                         event_func(event_notifier_priv->parent.pub);
1120                                         break;
1121                                 }
1122                         }
1123                 }
1124         }
1125 }
1126
1127 static
1128 void _event_enum_destroy(struct lttng_ust_event_common *event)
1129 {
1130
1131         switch (event->type) {
1132         case LTTNG_UST_EVENT_TYPE_RECORDER:
1133         {
1134                 struct lttng_ust_event_recorder *event_recorder = event->child;
1135                 struct lttng_ust_session *session = event_recorder->chan->session;
1136                 unsigned int i;
1137
1138                 /* Destroy enums of the current event. */
1139                 for (i = 0; i < event_recorder->parent->priv->desc->nr_fields; i++) {
1140                         struct lttng_ust_enum_desc *enum_desc;
1141                         struct lttng_ust_event_field *field;
1142                         struct lttng_enum *curr_enum;
1143
1144                         field = event_recorder->parent->priv->desc->fields[i];
1145                         switch (field->type->type) {
1146                         case lttng_ust_type_enum:
1147                                 enum_desc = lttng_ust_get_type_enum(field->type)->desc;
1148                                 break;
1149                         default:
1150                                 continue;
1151                         }
1152
1153                         curr_enum = lttng_ust_enum_get_from_desc(session, enum_desc);
1154                         if (curr_enum) {
1155                                 _lttng_enum_destroy(curr_enum);
1156                         }
1157                 }
1158                 break;
1159         }
1160         case LTTNG_UST_EVENT_TYPE_NOTIFIER:
1161                 break;
1162         default:
1163                 abort();
1164         }
1165         /* Destroy event. */
1166         _lttng_event_destroy(event);
1167 }
1168
1169 /*
1170  * Iterate over all the UST sessions to unregister and destroy all probes from
1171  * the probe provider descriptor received as argument. Must me called with the
1172  * ust_lock held.
1173  */
1174 void lttng_probe_provider_unregister_events(
1175                 struct lttng_ust_probe_desc *provider_desc)
1176 {
1177         /*
1178          * Iterate over all events in the probe provider descriptions and sessions
1179          * to queue the unregistration of the events.
1180          */
1181         probe_provider_event_for_each(provider_desc, _lttng_event_unregister);
1182
1183         /* Wait for grace period. */
1184         lttng_ust_urcu_synchronize_rcu();
1185         /* Prune the unregistration queue. */
1186         lttng_ust_tp_probe_prune_release_queue();
1187
1188         /*
1189          * It is now safe to destroy the events and remove them from the event list
1190          * and hashtables.
1191          */
1192         probe_provider_event_for_each(provider_desc, _event_enum_destroy);
1193 }
1194
1195 /*
1196  * Create events associated with an event enabler (if not already present),
1197  * and add backward reference from the event to the enabler.
1198  */
1199 static
1200 int lttng_event_enabler_ref_event_recorders(struct lttng_event_enabler *event_enabler)
1201 {
1202         struct lttng_ust_session *session = event_enabler->chan->session;
1203         struct lttng_ust_event_recorder_private *event_recorder_priv;
1204
1205         if (!lttng_event_enabler_as_enabler(event_enabler)->enabled)
1206                 goto end;
1207
1208         /* First ensure that probe events are created for this enabler. */
1209         lttng_create_event_recorder_if_missing(event_enabler);
1210
1211         /* For each event matching enabler in session event list. */
1212         cds_list_for_each_entry(event_recorder_priv, &session->priv->events_head, node) {
1213                 struct lttng_enabler_ref *enabler_ref;
1214
1215                 if (!lttng_event_enabler_match_event(event_enabler, event_recorder_priv->pub))
1216                         continue;
1217
1218                 enabler_ref = lttng_enabler_ref(&event_recorder_priv->parent.enablers_ref_head,
1219                         lttng_event_enabler_as_enabler(event_enabler));
1220                 if (!enabler_ref) {
1221                         /*
1222                          * If no backward ref, create it.
1223                          * Add backward ref from event to enabler.
1224                          */
1225                         enabler_ref = zmalloc(sizeof(*enabler_ref));
1226                         if (!enabler_ref)
1227                                 return -ENOMEM;
1228                         enabler_ref->ref = lttng_event_enabler_as_enabler(
1229                                 event_enabler);
1230                         cds_list_add(&enabler_ref->node,
1231                                 &event_recorder_priv->parent.enablers_ref_head);
1232                 }
1233
1234                 /*
1235                  * Link filter bytecodes if not linked yet.
1236                  */
1237                 lttng_enabler_link_bytecode(event_recorder_priv->parent.desc,
1238                         &session->priv->ctx,
1239                         &event_recorder_priv->pub->parent->filter_bytecode_runtime_head,
1240                         &lttng_event_enabler_as_enabler(event_enabler)->filter_bytecode_head);
1241
1242                 /* TODO: merge event context. */
1243         }
1244 end:
1245         return 0;
1246 }
1247
1248 /*
1249  * Called at library load: connect the probe on all enablers matching
1250  * this event.
1251  * Called with session mutex held.
1252  */
1253 int lttng_fix_pending_events(void)
1254 {
1255         struct lttng_ust_session_private *session_priv;
1256
1257         cds_list_for_each_entry(session_priv, &sessions, node) {
1258                 lttng_session_lazy_sync_event_enablers(session_priv->pub);
1259         }
1260         return 0;
1261 }
1262
1263 int lttng_fix_pending_event_notifiers(void)
1264 {
1265         struct lttng_event_notifier_group *event_notifier_group;
1266
1267         cds_list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
1268                 lttng_event_notifier_group_sync_enablers(event_notifier_group);
1269         }
1270         return 0;
1271 }
1272
1273 /*
1274  * For each session of the owner thread, execute pending statedump.
1275  * Only dump state for the sessions owned by the caller thread, because
1276  * we don't keep ust_lock across the entire iteration.
1277  */
1278 void lttng_handle_pending_statedump(void *owner)
1279 {
1280         struct lttng_ust_session_private *session_priv;
1281
1282         /* Execute state dump */
1283         do_lttng_ust_statedump(owner);
1284
1285         /* Clear pending state dump */
1286         if (ust_lock()) {
1287                 goto end;
1288         }
1289         cds_list_for_each_entry(session_priv, &sessions, node) {
1290                 if (session_priv->owner != owner)
1291                         continue;
1292                 if (!session_priv->statedump_pending)
1293                         continue;
1294                 session_priv->statedump_pending = 0;
1295         }
1296 end:
1297         ust_unlock();
1298         return;
1299 }
1300
1301 static
1302 void _lttng_event_destroy(struct lttng_ust_event_common *event)
1303 {
1304         struct lttng_enabler_ref *enabler_ref, *tmp_enabler_ref;
1305
1306         lttng_free_event_filter_runtime(event);
1307         /* Free event enabler refs */
1308         cds_list_for_each_entry_safe(enabler_ref, tmp_enabler_ref,
1309                         &event->priv->enablers_ref_head, node)
1310                 free(enabler_ref);
1311
1312         switch (event->type) {
1313         case LTTNG_UST_EVENT_TYPE_RECORDER:
1314         {
1315                 struct lttng_ust_event_recorder *event_recorder = event->child;
1316
1317                 /* Remove from event list. */
1318                 cds_list_del(&event_recorder->priv->node);
1319                 /* Remove from event hash table. */
1320                 cds_hlist_del(&event_recorder->priv->hlist);
1321
1322                 lttng_destroy_context(event_recorder->ctx);
1323                 free(event_recorder->parent);
1324                 free(event_recorder->priv);
1325                 free(event_recorder);
1326                 break;
1327         }
1328         case LTTNG_UST_EVENT_TYPE_NOTIFIER:
1329         {
1330                 struct lttng_ust_event_notifier *event_notifier = event->child;
1331
1332                 /* Remove from event list. */
1333                 cds_list_del(&event_notifier->priv->node);
1334                 /* Remove from event hash table. */
1335                 cds_hlist_del(&event_notifier->priv->hlist);
1336
1337                 free(event_notifier->priv);
1338                 free(event_notifier->parent);
1339                 free(event_notifier);
1340                 break;
1341         }
1342         default:
1343                 abort();
1344         }
1345 }
1346
1347 static
1348 void _lttng_enum_destroy(struct lttng_enum *_enum)
1349 {
1350         cds_list_del(&_enum->node);
1351         cds_hlist_del(&_enum->hlist);
1352         free(_enum);
1353 }
1354
1355 void lttng_ust_abi_events_exit(void)
1356 {
1357         struct lttng_ust_session_private *session_priv, *tmpsession_priv;
1358
1359         cds_list_for_each_entry_safe(session_priv, tmpsession_priv, &sessions, node)
1360                 lttng_session_destroy(session_priv->pub);
1361 }
1362
1363 /*
1364  * Enabler management.
1365  */
1366 struct lttng_event_enabler *lttng_event_enabler_create(
1367                 enum lttng_enabler_format_type format_type,
1368                 struct lttng_ust_abi_event *event_param,
1369                 struct lttng_channel *chan)
1370 {
1371         struct lttng_event_enabler *event_enabler;
1372
1373         event_enabler = zmalloc(sizeof(*event_enabler));
1374         if (!event_enabler)
1375                 return NULL;
1376         event_enabler->base.format_type = format_type;
1377         CDS_INIT_LIST_HEAD(&event_enabler->base.filter_bytecode_head);
1378         CDS_INIT_LIST_HEAD(&event_enabler->base.excluder_head);
1379         memcpy(&event_enabler->base.event_param, event_param,
1380                 sizeof(event_enabler->base.event_param));
1381         event_enabler->chan = chan;
1382         /* ctx left NULL */
1383         event_enabler->base.enabled = 0;
1384         cds_list_add(&event_enabler->node, &event_enabler->chan->session->priv->enablers_head);
1385         lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
1386
1387         return event_enabler;
1388 }
1389
1390 struct lttng_event_notifier_enabler *lttng_event_notifier_enabler_create(
1391                 struct lttng_event_notifier_group *event_notifier_group,
1392                 enum lttng_enabler_format_type format_type,
1393                 struct lttng_ust_abi_event_notifier *event_notifier_param)
1394 {
1395         struct lttng_event_notifier_enabler *event_notifier_enabler;
1396
1397         event_notifier_enabler = zmalloc(sizeof(*event_notifier_enabler));
1398         if (!event_notifier_enabler)
1399                 return NULL;
1400         event_notifier_enabler->base.format_type = format_type;
1401         CDS_INIT_LIST_HEAD(&event_notifier_enabler->base.filter_bytecode_head);
1402         CDS_INIT_LIST_HEAD(&event_notifier_enabler->capture_bytecode_head);
1403         CDS_INIT_LIST_HEAD(&event_notifier_enabler->base.excluder_head);
1404
1405         event_notifier_enabler->user_token = event_notifier_param->event.token;
1406         event_notifier_enabler->error_counter_index = event_notifier_param->error_counter_index;
1407         event_notifier_enabler->num_captures = 0;
1408
1409         memcpy(&event_notifier_enabler->base.event_param.name,
1410                 event_notifier_param->event.name,
1411                 sizeof(event_notifier_enabler->base.event_param.name));
1412         event_notifier_enabler->base.event_param.instrumentation =
1413                 event_notifier_param->event.instrumentation;
1414         event_notifier_enabler->base.event_param.loglevel =
1415                 event_notifier_param->event.loglevel;
1416         event_notifier_enabler->base.event_param.loglevel_type =
1417                 event_notifier_param->event.loglevel_type;
1418
1419         event_notifier_enabler->base.enabled = 0;
1420         event_notifier_enabler->group = event_notifier_group;
1421
1422         cds_list_add(&event_notifier_enabler->node,
1423                         &event_notifier_group->enablers_head);
1424
1425         lttng_event_notifier_group_sync_enablers(event_notifier_group);
1426
1427         return event_notifier_enabler;
1428 }
1429
1430 int lttng_event_enabler_enable(struct lttng_event_enabler *event_enabler)
1431 {
1432         lttng_event_enabler_as_enabler(event_enabler)->enabled = 1;
1433         lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
1434
1435         return 0;
1436 }
1437
1438 int lttng_event_enabler_disable(struct lttng_event_enabler *event_enabler)
1439 {
1440         lttng_event_enabler_as_enabler(event_enabler)->enabled = 0;
1441         lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
1442
1443         return 0;
1444 }
1445
1446 static
1447 void _lttng_enabler_attach_filter_bytecode(struct lttng_enabler *enabler,
1448                 struct lttng_ust_bytecode_node **bytecode)
1449 {
1450         (*bytecode)->enabler = enabler;
1451         cds_list_add_tail(&(*bytecode)->node, &enabler->filter_bytecode_head);
1452         /* Take ownership of bytecode */
1453         *bytecode = NULL;
1454 }
1455
1456 int lttng_event_enabler_attach_filter_bytecode(struct lttng_event_enabler *event_enabler,
1457                 struct lttng_ust_bytecode_node **bytecode)
1458 {
1459         _lttng_enabler_attach_filter_bytecode(
1460                 lttng_event_enabler_as_enabler(event_enabler), bytecode);
1461
1462         lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
1463         return 0;
1464 }
1465
1466 static
1467 void _lttng_enabler_attach_exclusion(struct lttng_enabler *enabler,
1468                 struct lttng_ust_excluder_node **excluder)
1469 {
1470         (*excluder)->enabler = enabler;
1471         cds_list_add_tail(&(*excluder)->node, &enabler->excluder_head);
1472         /* Take ownership of excluder */
1473         *excluder = NULL;
1474 }
1475
1476 int lttng_event_enabler_attach_exclusion(struct lttng_event_enabler *event_enabler,
1477                 struct lttng_ust_excluder_node **excluder)
1478 {
1479         _lttng_enabler_attach_exclusion(
1480                 lttng_event_enabler_as_enabler(event_enabler), excluder);
1481
1482         lttng_session_lazy_sync_event_enablers(event_enabler->chan->session);
1483         return 0;
1484 }
1485
1486 int lttng_event_notifier_enabler_enable(
1487                 struct lttng_event_notifier_enabler *event_notifier_enabler)
1488 {
1489         lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 1;
1490         lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
1491
1492         return 0;
1493 }
1494
1495 int lttng_event_notifier_enabler_disable(
1496                 struct lttng_event_notifier_enabler *event_notifier_enabler)
1497 {
1498         lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled = 0;
1499         lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
1500
1501         return 0;
1502 }
1503
1504 int lttng_event_notifier_enabler_attach_filter_bytecode(
1505                 struct lttng_event_notifier_enabler *event_notifier_enabler,
1506                 struct lttng_ust_bytecode_node **bytecode)
1507 {
1508         _lttng_enabler_attach_filter_bytecode(
1509                 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
1510                 bytecode);
1511
1512         lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
1513         return 0;
1514 }
1515
1516 int lttng_event_notifier_enabler_attach_capture_bytecode(
1517                 struct lttng_event_notifier_enabler *event_notifier_enabler,
1518                 struct lttng_ust_bytecode_node **bytecode)
1519 {
1520         (*bytecode)->enabler = lttng_event_notifier_enabler_as_enabler(
1521                         event_notifier_enabler);
1522         cds_list_add_tail(&(*bytecode)->node,
1523                         &event_notifier_enabler->capture_bytecode_head);
1524         /* Take ownership of bytecode */
1525         *bytecode = NULL;
1526         event_notifier_enabler->num_captures++;
1527
1528         lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
1529         return 0;
1530 }
1531
1532 int lttng_event_notifier_enabler_attach_exclusion(
1533                 struct lttng_event_notifier_enabler *event_notifier_enabler,
1534                 struct lttng_ust_excluder_node **excluder)
1535 {
1536         _lttng_enabler_attach_exclusion(
1537                 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler),
1538                 excluder);
1539
1540         lttng_event_notifier_group_sync_enablers(event_notifier_enabler->group);
1541         return 0;
1542 }
1543
1544 int lttng_attach_context(struct lttng_ust_abi_context *context_param,
1545                 union lttng_ust_abi_args *uargs,
1546                 struct lttng_ust_ctx **ctx, struct lttng_ust_session *session)
1547 {
1548         /*
1549          * We cannot attach a context after trace has been started for a
1550          * session because the metadata does not allow expressing this
1551          * information outside of the original channel scope.
1552          */
1553         if (session->priv->been_active)
1554                 return -EPERM;
1555
1556         switch (context_param->ctx) {
1557         case LTTNG_UST_ABI_CONTEXT_PTHREAD_ID:
1558                 return lttng_add_pthread_id_to_ctx(ctx);
1559         case LTTNG_UST_ABI_CONTEXT_PERF_THREAD_COUNTER:
1560         {
1561                 struct lttng_ust_abi_perf_counter_ctx *perf_ctx_param;
1562
1563                 perf_ctx_param = &context_param->u.perf_counter;
1564                 return lttng_add_perf_counter_to_ctx(
1565                         perf_ctx_param->type,
1566                         perf_ctx_param->config,
1567                         perf_ctx_param->name,
1568                         ctx);
1569         }
1570         case LTTNG_UST_ABI_CONTEXT_VTID:
1571                 return lttng_add_vtid_to_ctx(ctx);
1572         case LTTNG_UST_ABI_CONTEXT_VPID:
1573                 return lttng_add_vpid_to_ctx(ctx);
1574         case LTTNG_UST_ABI_CONTEXT_PROCNAME:
1575                 return lttng_add_procname_to_ctx(ctx);
1576         case LTTNG_UST_ABI_CONTEXT_IP:
1577                 return lttng_add_ip_to_ctx(ctx);
1578         case LTTNG_UST_ABI_CONTEXT_CPU_ID:
1579                 return lttng_add_cpu_id_to_ctx(ctx);
1580         case LTTNG_UST_ABI_CONTEXT_APP_CONTEXT:
1581                 return lttng_ust_add_app_context_to_ctx_rcu(uargs->app_context.ctxname,
1582                         ctx);
1583         case LTTNG_UST_ABI_CONTEXT_CGROUP_NS:
1584                 return lttng_add_cgroup_ns_to_ctx(ctx);
1585         case LTTNG_UST_ABI_CONTEXT_IPC_NS:
1586                 return lttng_add_ipc_ns_to_ctx(ctx);
1587         case LTTNG_UST_ABI_CONTEXT_MNT_NS:
1588                 return lttng_add_mnt_ns_to_ctx(ctx);
1589         case LTTNG_UST_ABI_CONTEXT_NET_NS:
1590                 return lttng_add_net_ns_to_ctx(ctx);
1591         case LTTNG_UST_ABI_CONTEXT_PID_NS:
1592                 return lttng_add_pid_ns_to_ctx(ctx);
1593         case LTTNG_UST_ABI_CONTEXT_TIME_NS:
1594                 return lttng_add_time_ns_to_ctx(ctx);
1595         case LTTNG_UST_ABI_CONTEXT_USER_NS:
1596                 return lttng_add_user_ns_to_ctx(ctx);
1597         case LTTNG_UST_ABI_CONTEXT_UTS_NS:
1598                 return lttng_add_uts_ns_to_ctx(ctx);
1599         case LTTNG_UST_ABI_CONTEXT_VUID:
1600                 return lttng_add_vuid_to_ctx(ctx);
1601         case LTTNG_UST_ABI_CONTEXT_VEUID:
1602                 return lttng_add_veuid_to_ctx(ctx);
1603         case LTTNG_UST_ABI_CONTEXT_VSUID:
1604                 return lttng_add_vsuid_to_ctx(ctx);
1605         case LTTNG_UST_ABI_CONTEXT_VGID:
1606                 return lttng_add_vgid_to_ctx(ctx);
1607         case LTTNG_UST_ABI_CONTEXT_VEGID:
1608                 return lttng_add_vegid_to_ctx(ctx);
1609         case LTTNG_UST_ABI_CONTEXT_VSGID:
1610                 return lttng_add_vsgid_to_ctx(ctx);
1611         default:
1612                 return -EINVAL;
1613         }
1614 }
1615
1616 int lttng_event_enabler_attach_context(struct lttng_event_enabler *enabler,
1617                 struct lttng_ust_abi_context *context_param)
1618 {
1619         return -ENOSYS;
1620 }
1621
1622 void lttng_event_enabler_destroy(struct lttng_event_enabler *event_enabler)
1623 {
1624         if (!event_enabler) {
1625                 return;
1626         }
1627         cds_list_del(&event_enabler->node);
1628
1629         lttng_enabler_destroy(lttng_event_enabler_as_enabler(event_enabler));
1630
1631         lttng_destroy_context(event_enabler->ctx);
1632         free(event_enabler);
1633 }
1634
1635 /*
1636  * lttng_session_sync_event_enablers should be called just before starting a
1637  * session.
1638  */
1639 static
1640 void lttng_session_sync_event_enablers(struct lttng_ust_session *session)
1641 {
1642         struct lttng_event_enabler *event_enabler;
1643         struct lttng_ust_event_recorder_private *event_recorder_priv;
1644
1645         cds_list_for_each_entry(event_enabler, &session->priv->enablers_head, node)
1646                 lttng_event_enabler_ref_event_recorders(event_enabler);
1647         /*
1648          * For each event, if at least one of its enablers is enabled,
1649          * and its channel and session transient states are enabled, we
1650          * enable the event, else we disable it.
1651          */
1652         cds_list_for_each_entry(event_recorder_priv, &session->priv->events_head, node) {
1653                 struct lttng_enabler_ref *enabler_ref;
1654                 struct lttng_ust_bytecode_runtime *runtime;
1655                 int enabled = 0, has_enablers_without_bytecode = 0;
1656
1657                 /* Enable events */
1658                 cds_list_for_each_entry(enabler_ref,
1659                                 &event_recorder_priv->parent.enablers_ref_head, node) {
1660                         if (enabler_ref->ref->enabled) {
1661                                 enabled = 1;
1662                                 break;
1663                         }
1664                 }
1665                 /*
1666                  * Enabled state is based on union of enablers, with
1667                  * intesection of session and channel transient enable
1668                  * states.
1669                  */
1670                 enabled = enabled && session->priv->tstate && event_recorder_priv->pub->chan->tstate;
1671
1672                 CMM_STORE_SHARED(event_recorder_priv->pub->parent->enabled, enabled);
1673                 /*
1674                  * Sync tracepoint registration with event enabled
1675                  * state.
1676                  */
1677                 if (enabled) {
1678                         if (!event_recorder_priv->parent.registered)
1679                                 register_event(event_recorder_priv->parent.pub);
1680                 } else {
1681                         if (event_recorder_priv->parent.registered)
1682                                 unregister_event(event_recorder_priv->parent.pub);
1683                 }
1684
1685                 /* Check if has enablers without bytecode enabled */
1686                 cds_list_for_each_entry(enabler_ref,
1687                                 &event_recorder_priv->parent.enablers_ref_head, node) {
1688                         if (enabler_ref->ref->enabled
1689                                         && cds_list_empty(&enabler_ref->ref->filter_bytecode_head)) {
1690                                 has_enablers_without_bytecode = 1;
1691                                 break;
1692                         }
1693                 }
1694                 event_recorder_priv->pub->parent->has_enablers_without_bytecode =
1695                         has_enablers_without_bytecode;
1696
1697                 /* Enable filters */
1698                 cds_list_for_each_entry(runtime,
1699                                 &event_recorder_priv->pub->parent->filter_bytecode_runtime_head, node) {
1700                         lttng_bytecode_filter_sync_state(runtime);
1701                 }
1702         }
1703         lttng_ust_tp_probe_prune_release_queue();
1704 }
1705
1706 /* Support for event notifier is introduced by probe provider major version 2. */
1707 static
1708 bool lttng_ust_probe_supports_event_notifier(struct lttng_ust_probe_desc *probe_desc)
1709 {
1710         return probe_desc->major >= 2;
1711 }
1712
1713 static
1714 void lttng_create_event_notifier_if_missing(
1715                 struct lttng_event_notifier_enabler *event_notifier_enabler)
1716 {
1717         struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
1718         struct lttng_ust_probe_desc *probe_desc;
1719         struct cds_list_head *probe_list;
1720         int i;
1721
1722         probe_list = lttng_get_probe_list_head();
1723
1724         cds_list_for_each_entry(probe_desc, probe_list, head) {
1725                 for (i = 0; i < probe_desc->nr_events; i++) {
1726                         int ret;
1727                         bool found = false;
1728                         struct lttng_ust_event_desc *desc;
1729                         struct lttng_ust_event_notifier_private *event_notifier_priv;
1730                         struct cds_hlist_head *head;
1731                         struct cds_hlist_node *node;
1732
1733                         desc = probe_desc->event_desc[i];
1734
1735                         if (!lttng_desc_match_enabler(desc,
1736                                         lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
1737                                 continue;
1738
1739                         /*
1740                          * Given the current event_notifier group, get the bucket that
1741                          * the target event_notifier would be if it was already
1742                          * created.
1743                          */
1744                         head = borrow_hash_table_bucket(
1745                                 event_notifier_group->event_notifiers_ht.table,
1746                                 LTTNG_UST_EVENT_NOTIFIER_HT_SIZE, desc);
1747
1748                         cds_hlist_for_each_entry(event_notifier_priv, node, head, hlist) {
1749                                 /*
1750                                  * Check if event_notifier already exists by checking
1751                                  * if the event_notifier and enabler share the same
1752                                  * description and id.
1753                                  */
1754                                 if (event_notifier_priv->parent.desc == desc &&
1755                                                 event_notifier_priv->parent.user_token == event_notifier_enabler->user_token) {
1756                                         found = true;
1757                                         break;
1758                                 }
1759                         }
1760
1761                         if (found)
1762                                 continue;
1763
1764                         /* Check that the probe supports event notifiers, else report the error. */
1765                         if (!lttng_ust_probe_supports_event_notifier(probe_desc)) {
1766                                 ERR("Probe \"%s\" contains event \"%s\" which matches an enabled event notifier, "
1767                                         "but its version (%u.%u) is too old and does not implement event notifiers. "
1768                                         "It needs to be recompiled against a newer version of LTTng-UST, otherwise "
1769                                         "this event will not generate any notification.",
1770                                         probe_desc->provider,
1771                                         desc->name,
1772                                         probe_desc->major,
1773                                         probe_desc->minor);
1774                                 continue;
1775                         }
1776                         /*
1777                          * We need to create a event_notifier for this event probe.
1778                          */
1779                         ret = lttng_event_notifier_create(desc,
1780                                 event_notifier_enabler->user_token,
1781                                 event_notifier_enabler->error_counter_index,
1782                                 event_notifier_group);
1783                         if (ret) {
1784                                 DBG("Unable to create event_notifier %s, error %d\n",
1785                                         probe_desc->event_desc[i]->name, ret);
1786                         }
1787                 }
1788         }
1789 }
1790
1791 /*
1792  * Create event_notifiers associated with a event_notifier enabler (if not already present).
1793  */
1794 static
1795 int lttng_event_notifier_enabler_ref_event_notifiers(
1796                 struct lttng_event_notifier_enabler *event_notifier_enabler)
1797 {
1798         struct lttng_event_notifier_group *event_notifier_group = event_notifier_enabler->group;
1799         struct lttng_ust_event_notifier_private *event_notifier_priv;
1800
1801          /*
1802           * Only try to create event_notifiers for enablers that are enabled, the user
1803           * might still be attaching filter or exclusion to the
1804           * event_notifier_enabler.
1805           */
1806         if (!lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->enabled)
1807                 goto end;
1808
1809         /* First, ensure that probe event_notifiers are created for this enabler. */
1810         lttng_create_event_notifier_if_missing(event_notifier_enabler);
1811
1812         /* Link the created event_notifier with its associated enabler. */
1813         cds_list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
1814                 struct lttng_enabler_ref *enabler_ref;
1815
1816                 if (!lttng_event_notifier_enabler_match_event_notifier(event_notifier_enabler, event_notifier_priv->pub))
1817                         continue;
1818
1819                 enabler_ref = lttng_enabler_ref(&event_notifier_priv->parent.enablers_ref_head,
1820                         lttng_event_notifier_enabler_as_enabler(event_notifier_enabler));
1821                 if (!enabler_ref) {
1822                         /*
1823                          * If no backward ref, create it.
1824                          * Add backward ref from event_notifier to enabler.
1825                          */
1826                         enabler_ref = zmalloc(sizeof(*enabler_ref));
1827                         if (!enabler_ref)
1828                                 return -ENOMEM;
1829
1830                         enabler_ref->ref = lttng_event_notifier_enabler_as_enabler(
1831                                 event_notifier_enabler);
1832                         cds_list_add(&enabler_ref->node,
1833                                 &event_notifier_priv->parent.enablers_ref_head);
1834                 }
1835
1836                 /*
1837                  * Link filter bytecodes if not linked yet.
1838                  */
1839                 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
1840                         &event_notifier_group->ctx,
1841                         &event_notifier_priv->pub->parent->filter_bytecode_runtime_head,
1842                         &lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)->filter_bytecode_head);
1843
1844                 /*
1845                  * Link capture bytecodes if not linked yet.
1846                  */
1847                 lttng_enabler_link_bytecode(event_notifier_priv->parent.desc,
1848                         &event_notifier_group->ctx, &event_notifier_priv->pub->capture_bytecode_runtime_head,
1849                         &event_notifier_enabler->capture_bytecode_head);
1850
1851                 event_notifier_priv->num_captures = event_notifier_enabler->num_captures;
1852         }
1853 end:
1854         return 0;
1855 }
1856
1857 static
1858 void lttng_event_notifier_group_sync_enablers(struct lttng_event_notifier_group *event_notifier_group)
1859 {
1860         struct lttng_event_notifier_enabler *event_notifier_enabler;
1861         struct lttng_ust_event_notifier_private *event_notifier_priv;
1862
1863         cds_list_for_each_entry(event_notifier_enabler, &event_notifier_group->enablers_head, node)
1864                 lttng_event_notifier_enabler_ref_event_notifiers(event_notifier_enabler);
1865
1866         /*
1867          * For each event_notifier, if at least one of its enablers is enabled,
1868          * we enable the event_notifier, else we disable it.
1869          */
1870         cds_list_for_each_entry(event_notifier_priv, &event_notifier_group->event_notifiers_head, node) {
1871                 struct lttng_enabler_ref *enabler_ref;
1872                 struct lttng_ust_bytecode_runtime *runtime;
1873                 int enabled = 0, has_enablers_without_bytecode = 0;
1874
1875                 /* Enable event_notifiers */
1876                 cds_list_for_each_entry(enabler_ref,
1877                                 &event_notifier_priv->parent.enablers_ref_head, node) {
1878                         if (enabler_ref->ref->enabled) {
1879                                 enabled = 1;
1880                                 break;
1881                         }
1882                 }
1883
1884                 CMM_STORE_SHARED(event_notifier_priv->pub->parent->enabled, enabled);
1885                 /*
1886                  * Sync tracepoint registration with event_notifier enabled
1887                  * state.
1888                  */
1889                 if (enabled) {
1890                         if (!event_notifier_priv->parent.registered)
1891                                 register_event(event_notifier_priv->parent.pub);
1892                 } else {
1893                         if (event_notifier_priv->parent.registered)
1894                                 unregister_event(event_notifier_priv->parent.pub);
1895                 }
1896
1897                 /* Check if has enablers without bytecode enabled */
1898                 cds_list_for_each_entry(enabler_ref,
1899                                 &event_notifier_priv->parent.enablers_ref_head, node) {
1900                         if (enabler_ref->ref->enabled
1901                                         && cds_list_empty(&enabler_ref->ref->filter_bytecode_head)) {
1902                                 has_enablers_without_bytecode = 1;
1903                                 break;
1904                         }
1905                 }
1906                 event_notifier_priv->pub->parent->has_enablers_without_bytecode =
1907                         has_enablers_without_bytecode;
1908
1909                 /* Enable filters */
1910                 cds_list_for_each_entry(runtime,
1911                                 &event_notifier_priv->pub->parent->filter_bytecode_runtime_head, node) {
1912                         lttng_bytecode_filter_sync_state(runtime);
1913                 }
1914
1915                 /* Enable captures. */
1916                 cds_list_for_each_entry(runtime,
1917                                 &event_notifier_priv->pub->capture_bytecode_runtime_head, node) {
1918                         lttng_bytecode_capture_sync_state(runtime);
1919                 }
1920         }
1921         lttng_ust_tp_probe_prune_release_queue();
1922 }
1923
1924 /*
1925  * Apply enablers to session events, adding events to session if need
1926  * be. It is required after each modification applied to an active
1927  * session, and right before session "start".
1928  * "lazy" sync means we only sync if required.
1929  */
1930 static
1931 void lttng_session_lazy_sync_event_enablers(struct lttng_ust_session *session)
1932 {
1933         /* We can skip if session is not active */
1934         if (!session->active)
1935                 return;
1936         lttng_session_sync_event_enablers(session);
1937 }
1938
1939 /*
1940  * Update all sessions with the given app context.
1941  * Called with ust lock held.
1942  * This is invoked when an application context gets loaded/unloaded. It
1943  * ensures the context callbacks are in sync with the application
1944  * context (either app context callbacks, or dummy callbacks).
1945  */
1946 void lttng_ust_context_set_session_provider(const char *name,
1947                 size_t (*get_size)(struct lttng_ust_ctx_field *field, size_t offset),
1948                 void (*record)(struct lttng_ust_ctx_field *field,
1949                         struct lttng_ust_lib_ring_buffer_ctx *ctx,
1950                         struct lttng_channel *chan),
1951                 void (*get_value)(struct lttng_ust_ctx_field *field,
1952                         struct lttng_ust_ctx_value *value))
1953 {
1954         struct lttng_ust_session_private *session_priv;
1955
1956         cds_list_for_each_entry(session_priv, &sessions, node) {
1957                 struct lttng_channel *chan;
1958                 struct lttng_ust_event_recorder_private *event_recorder_priv;
1959                 int ret;
1960
1961                 ret = lttng_ust_context_set_provider_rcu(&session_priv->ctx,
1962                                 name, get_size, record, get_value);
1963                 if (ret)
1964                         abort();
1965                 cds_list_for_each_entry(chan, &session_priv->chan_head, node) {
1966                         ret = lttng_ust_context_set_provider_rcu(&chan->ctx,
1967                                         name, get_size, record, get_value);
1968                         if (ret)
1969                                 abort();
1970                 }
1971                 cds_list_for_each_entry(event_recorder_priv, &session_priv->events_head, node) {
1972                         ret = lttng_ust_context_set_provider_rcu(&event_recorder_priv->pub->ctx,
1973                                         name, get_size, record, get_value);
1974                         if (ret)
1975                                 abort();
1976                 }
1977         }
1978 }
1979
1980 /*
1981  * Update all event_notifier groups with the given app context.
1982  * Called with ust lock held.
1983  * This is invoked when an application context gets loaded/unloaded. It
1984  * ensures the context callbacks are in sync with the application
1985  * context (either app context callbacks, or dummy callbacks).
1986  */
1987 void lttng_ust_context_set_event_notifier_group_provider(const char *name,
1988                 size_t (*get_size)(struct lttng_ust_ctx_field *field, size_t offset),
1989                 void (*record)(struct lttng_ust_ctx_field *field,
1990                         struct lttng_ust_lib_ring_buffer_ctx *ctx,
1991                         struct lttng_channel *chan),
1992                 void (*get_value)(struct lttng_ust_ctx_field *field,
1993                         struct lttng_ust_ctx_value *value))
1994 {
1995         struct lttng_event_notifier_group *event_notifier_group;
1996
1997         cds_list_for_each_entry(event_notifier_group, &event_notifier_groups, node) {
1998                 int ret;
1999
2000                 ret = lttng_ust_context_set_provider_rcu(
2001                                 &event_notifier_group->ctx,
2002                                 name, get_size, record, get_value);
2003                 if (ret)
2004                         abort();
2005         }
2006 }