liblttng-ust/lttng-ust-abi.c

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * LTTng UST ABI
   7  *
   8  * Mimic system calls for:
   9  * - session creation, returns an object descriptor or failure.
  10  *   - channel creation, returns an object descriptor or failure.
  11  *     - Operates on a session object descriptor
  12  *     - Takes all channel options as parameters.
  13  *   - stream get, returns an object descriptor or failure.
  14  *     - Operates on a channel object descriptor.
  15  *   - stream notifier get, returns an object descriptor or failure.
  16  *     - Operates on a channel object descriptor.
  17  *   - event creation, returns an object descriptor or failure.
  18  *     - Operates on a channel object descriptor
  19  *     - Takes an event name as parameter
  20  *     - Takes an instrumentation source as parameter
  21  *       - e.g. tracepoints, dynamic_probes...
  22  *     - Takes instrumentation source specific arguments.
  23  */
  24
  25 #define _LGPL_SOURCE
  26 #include <fcntl.h>
  27 #include <stdint.h>
  28 #include <unistd.h>
  29
  30 #include <urcu/compiler.h>
  31 #include <urcu/list.h>
  32
  33 #include <lttng/tracepoint.h>
  34 #include <lttng/ust-abi.h>
  35 #include <lttng/ust-error.h>
  36 #include <lttng/ust-events.h>
  37 #include <lttng/ust-version.h>
  38 #include <ust-fd.h>
  39 #include <usterr-signal-safe.h>
  40
  41 #include "../libringbuffer/frontend_types.h"
  42 #include "../libringbuffer/shm.h"
  43 #include "../libcounter/counter.h"
  44 #include "tracepoint-internal.h"
  45 #include "lttng-tracer.h"
  46 #include "string-utils.h"
  47 #include "ust-events-internal.h"
  48 #include "context-internal.h"
  49 #include "ust-helper.h"
  50
  51 #define OBJ_NAME_LEN    16
  52
  53 static int lttng_ust_abi_close_in_progress;
  54
  55 static
  56 int lttng_abi_tracepoint_list(void *owner);
  57 static
  58 int lttng_abi_tracepoint_field_list(void *owner);
  59
  60 /*
  61  * Object descriptor table. Should be protected from concurrent access
  62  * by the caller.
  63  */
  64
  65 struct lttng_ust_abi_obj {
  66         union {
  67                 struct {
  68                         void *private_data;
  69                         const struct lttng_ust_abi_objd_ops *ops;
  70                         int f_count;
  71                         int owner_ref;  /* has ref from owner */
  72                         void *owner;
  73                         char name[OBJ_NAME_LEN];
  74                 } s;
  75                 int freelist_next;      /* offset freelist. end is -1. */
  76         } u;
  77 };
  78
  79 struct lttng_ust_abi_objd_table {
  80         struct lttng_ust_abi_obj *array;
  81         unsigned int len, allocated_len;
  82         int freelist_head;              /* offset freelist head. end is -1 */
  83 };
  84
  85 static struct lttng_ust_abi_objd_table objd_table = {
  86         .freelist_head = -1,
  87 };
  88
  89 static
  90 int objd_alloc(void *private_data, const struct lttng_ust_abi_objd_ops *ops,
  91                 void *owner, const char *name)
  92 {
  93         struct lttng_ust_abi_obj *obj;
  94
  95         if (objd_table.freelist_head != -1) {
  96                 obj = &objd_table.array[objd_table.freelist_head];
  97                 objd_table.freelist_head = obj->u.freelist_next;
  98                 goto end;
  99         }
 100
 101         if (objd_table.len >= objd_table.allocated_len) {
 102                 unsigned int new_allocated_len, old_allocated_len;
 103                 struct lttng_ust_abi_obj *new_table, *old_table;
 104
 105                 old_allocated_len = objd_table.allocated_len;
 106                 old_table = objd_table.array;
 107                 if (!old_allocated_len)
 108                         new_allocated_len = 1;
 109                 else
 110                         new_allocated_len = old_allocated_len << 1;
 111                 new_table = zmalloc(sizeof(struct lttng_ust_abi_obj) * new_allocated_len);
 112                 if (!new_table)
 113                         return -ENOMEM;
 114                 memcpy(new_table, old_table,
 115                        sizeof(struct lttng_ust_abi_obj) * old_allocated_len);
 116                 free(old_table);
 117                 objd_table.array = new_table;
 118                 objd_table.allocated_len = new_allocated_len;
 119         }
 120         obj = &objd_table.array[objd_table.len];
 121         objd_table.len++;
 122 end:
 123         obj->u.s.private_data = private_data;
 124         obj->u.s.ops = ops;
 125         obj->u.s.f_count = 2;   /* count == 1 : object is allocated */
 126                                 /* count == 2 : allocated + hold ref */
 127         obj->u.s.owner_ref = 1; /* One owner reference */
 128         obj->u.s.owner = owner;
 129         strncpy(obj->u.s.name, name, OBJ_NAME_LEN);
 130         obj->u.s.name[OBJ_NAME_LEN - 1] = '\0';
 131         return obj - objd_table.array;
 132 }
 133
 134 static
 135 struct lttng_ust_abi_obj *_objd_get(int id)
 136 {
 137         if (id >= objd_table.len)
 138                 return NULL;
 139         if (!objd_table.array[id].u.s.f_count)
 140                 return NULL;
 141         return &objd_table.array[id];
 142 }
 143
 144 static
 145 void *objd_private(int id)
 146 {
 147         struct lttng_ust_abi_obj *obj = _objd_get(id);
 148         assert(obj);
 149         return obj->u.s.private_data;
 150 }
 151
 152 static
 153 void objd_set_private(int id, void *private_data)
 154 {
 155         struct lttng_ust_abi_obj *obj = _objd_get(id);
 156         assert(obj);
 157         obj->u.s.private_data = private_data;
 158 }
 159
 160 const struct lttng_ust_abi_objd_ops *lttng_ust_abi_objd_ops(int id)
 161 {
 162         struct lttng_ust_abi_obj *obj = _objd_get(id);
 163
 164         if (!obj)
 165                 return NULL;
 166         return obj->u.s.ops;
 167 }
 168
 169 static
 170 void objd_free(int id)
 171 {
 172         struct lttng_ust_abi_obj *obj = _objd_get(id);
 173
 174         assert(obj);
 175         obj->u.freelist_next = objd_table.freelist_head;
 176         objd_table.freelist_head = obj - objd_table.array;
 177         assert(obj->u.s.f_count == 1);
 178         obj->u.s.f_count = 0;   /* deallocated */
 179 }
 180
 181 static
 182 void objd_ref(int id)
 183 {
 184         struct lttng_ust_abi_obj *obj = _objd_get(id);
 185         assert(obj != NULL);
 186         obj->u.s.f_count++;
 187 }
 188
 189 int lttng_ust_abi_objd_unref(int id, int is_owner)
 190 {
 191         struct lttng_ust_abi_obj *obj = _objd_get(id);
 192
 193         if (!obj)
 194                 return -EINVAL;
 195         if (obj->u.s.f_count == 1) {
 196                 ERR("Reference counting error\n");
 197                 return -EINVAL;
 198         }
 199         if (is_owner) {
 200                 if (!obj->u.s.owner_ref) {
 201                         ERR("Error decrementing owner reference");
 202                         return -EINVAL;
 203                 }
 204                 obj->u.s.owner_ref--;
 205         }
 206         if ((--obj->u.s.f_count) == 1) {
 207                 const struct lttng_ust_abi_objd_ops *ops = lttng_ust_abi_objd_ops(id);
 208
 209                 if (ops->release)
 210                         ops->release(id);
 211                 objd_free(id);
 212         }
 213         return 0;
 214 }
 215
 216 static
 217 void objd_table_destroy(void)
 218 {
 219         int i;
 220
 221         for (i = 0; i < objd_table.allocated_len; i++) {
 222                 struct lttng_ust_abi_obj *obj;
 223
 224                 obj = _objd_get(i);
 225                 if (!obj)
 226                         continue;
 227                 if (!obj->u.s.owner_ref)
 228                         continue;       /* only unref owner ref. */
 229                 (void) lttng_ust_abi_objd_unref(i, 1);
 230         }
 231         free(objd_table.array);
 232         objd_table.array = NULL;
 233         objd_table.len = 0;
 234         objd_table.allocated_len = 0;
 235         objd_table.freelist_head = -1;
 236 }
 237
 238 const char *lttng_ust_obj_get_name(int id)
 239 {
 240         struct lttng_ust_abi_obj *obj = _objd_get(id);
 241
 242         if (!obj)
 243                 return NULL;
 244         return obj->u.s.name;
 245 }
 246
 247 void lttng_ust_abi_objd_table_owner_cleanup(void *owner)
 248 {
 249         int i;
 250
 251         for (i = 0; i < objd_table.allocated_len; i++) {
 252                 struct lttng_ust_abi_obj *obj;
 253
 254                 obj = _objd_get(i);
 255                 if (!obj)
 256                         continue;
 257                 if (!obj->u.s.owner)
 258                         continue;       /* skip root handles */
 259                 if (!obj->u.s.owner_ref)
 260                         continue;       /* only unref owner ref. */
 261                 if (obj->u.s.owner == owner)
 262                         (void) lttng_ust_abi_objd_unref(i, 1);
 263         }
 264 }
 265
 266 /*
 267  * This is LTTng's own personal way to create an ABI for sessiond.
 268  * We send commands over a socket.
 269  */
 270
 271 static const struct lttng_ust_abi_objd_ops lttng_ops;
 272 static const struct lttng_ust_abi_objd_ops lttng_event_notifier_group_ops;
 273 static const struct lttng_ust_abi_objd_ops lttng_session_ops;
 274 static const struct lttng_ust_abi_objd_ops lttng_channel_ops;
 275 static const struct lttng_ust_abi_objd_ops lttng_event_enabler_ops;
 276 static const struct lttng_ust_abi_objd_ops lttng_event_notifier_enabler_ops;
 277 static const struct lttng_ust_abi_objd_ops lttng_tracepoint_list_ops;
 278 static const struct lttng_ust_abi_objd_ops lttng_tracepoint_field_list_ops;
 279
 280 int lttng_abi_create_root_handle(void)
 281 {
 282         int root_handle;
 283
 284         /* root handles have NULL owners */
 285         root_handle = objd_alloc(NULL, &lttng_ops, NULL, "root");
 286         return root_handle;
 287 }
 288
 289 static
 290 int lttng_is_channel_ready(struct lttng_channel *lttng_chan)
 291 {
 292         struct lttng_ust_lib_ring_buffer_channel *chan;
 293         unsigned int nr_streams, exp_streams;
 294
 295         chan = lttng_chan->chan;
 296         nr_streams = channel_handle_get_nr_streams(lttng_chan->handle);
 297         exp_streams = chan->nr_streams;
 298         return nr_streams == exp_streams;
 299 }
 300
 301 static
 302 int lttng_abi_create_session(void *owner)
 303 {
 304         struct lttng_ust_session *session;
 305         int session_objd, ret;
 306
 307         session = lttng_session_create();
 308         if (!session)
 309                 return -ENOMEM;
 310         session_objd = objd_alloc(session, &lttng_session_ops, owner, "session");
 311         if (session_objd < 0) {
 312                 ret = session_objd;
 313                 goto objd_error;
 314         }
 315         session->priv->objd = session_objd;
 316         session->priv->owner = owner;
 317         return session_objd;
 318
 319 objd_error:
 320         lttng_session_destroy(session);
 321         return ret;
 322 }
 323
 324 static
 325 long lttng_abi_tracer_version(int objd,
 326         struct lttng_ust_abi_tracer_version *v)
 327 {
 328         v->major = LTTNG_UST_MAJOR_VERSION;
 329         v->minor = LTTNG_UST_MINOR_VERSION;
 330         v->patchlevel = LTTNG_UST_PATCHLEVEL_VERSION;
 331         return 0;
 332 }
 333
 334 static
 335 int lttng_abi_event_notifier_send_fd(void *owner, int *event_notifier_notif_fd)
 336 {
 337         struct lttng_event_notifier_group *event_notifier_group;
 338         int event_notifier_group_objd, ret, fd_flag;
 339
 340         event_notifier_group = lttng_event_notifier_group_create();
 341         if (!event_notifier_group)
 342                 return -ENOMEM;
 343
 344         /*
 345          * Set this file descriptor as NON-BLOCKING.
 346          */
 347         fd_flag = fcntl(*event_notifier_notif_fd, F_GETFL);
 348
 349         fd_flag |= O_NONBLOCK;
 350
 351         ret = fcntl(*event_notifier_notif_fd, F_SETFL, fd_flag);
 352         if (ret) {
 353                 ret = -errno;
 354                 goto fd_error;
 355         }
 356
 357         event_notifier_group_objd = objd_alloc(event_notifier_group,
 358                 &lttng_event_notifier_group_ops, owner, "event_notifier_group");
 359         if (event_notifier_group_objd < 0) {
 360                 ret = event_notifier_group_objd;
 361                 goto objd_error;
 362         }
 363
 364         event_notifier_group->objd = event_notifier_group_objd;
 365         event_notifier_group->owner = owner;
 366         event_notifier_group->notification_fd = *event_notifier_notif_fd;
 367         /* Object descriptor takes ownership of notification fd. */
 368         *event_notifier_notif_fd = -1;
 369
 370         return event_notifier_group_objd;
 371
 372 objd_error:
 373         lttng_event_notifier_group_destroy(event_notifier_group);
 374 fd_error:
 375         return ret;
 376 }
 377
 378 static
 379 long lttng_abi_add_context(int objd,
 380         struct lttng_ust_abi_context *context_param,
 381         union lttng_ust_abi_args *uargs,
 382         struct lttng_ust_ctx **ctx, struct lttng_ust_session *session)
 383 {
 384         return lttng_attach_context(context_param, uargs, ctx, session);
 385 }
 386
 387 /**
 388  *      lttng_cmd - lttng control through socket commands
 389  *
 390  *      @objd: the object descriptor
 391  *      @cmd: the command
 392  *      @arg: command arg
 393  *      @uargs: UST arguments (internal)
 394  *      @owner: objd owner
 395  *
 396  *      This descriptor implements lttng commands:
 397  *      LTTNG_UST_ABI_SESSION
 398  *              Returns a LTTng trace session object descriptor
 399  *      LTTNG_UST_ABI_TRACER_VERSION
 400  *              Returns the LTTng kernel tracer version
 401  *      LTTNG_UST_ABI_TRACEPOINT_LIST
 402  *              Returns a file descriptor listing available tracepoints
 403  *      LTTNG_UST_ABI_TRACEPOINT_FIELD_LIST
 404  *              Returns a file descriptor listing available tracepoint fields
 405  *      LTTNG_UST_ABI_WAIT_QUIESCENT
 406  *              Returns after all previously running probes have completed
 407  *
 408  * The returned session will be deleted when its file descriptor is closed.
 409  */
 410 static
 411 long lttng_cmd(int objd, unsigned int cmd, unsigned long arg,
 412         union lttng_ust_abi_args *uargs, void *owner)
 413 {
 414         switch (cmd) {
 415         case LTTNG_UST_ABI_SESSION:
 416                 return lttng_abi_create_session(owner);
 417         case LTTNG_UST_ABI_TRACER_VERSION:
 418                 return lttng_abi_tracer_version(objd,
 419                                 (struct lttng_ust_abi_tracer_version *) arg);
 420         case LTTNG_UST_ABI_TRACEPOINT_LIST:
 421                 return lttng_abi_tracepoint_list(owner);
 422         case LTTNG_UST_ABI_TRACEPOINT_FIELD_LIST:
 423                 return lttng_abi_tracepoint_field_list(owner);
 424         case LTTNG_UST_ABI_WAIT_QUIESCENT:
 425                 lttng_ust_urcu_synchronize_rcu();
 426                 return 0;
 427         case LTTNG_UST_ABI_EVENT_NOTIFIER_GROUP_CREATE:
 428                 return lttng_abi_event_notifier_send_fd(owner,
 429                         &uargs->event_notifier_handle.event_notifier_notif_fd);
 430         default:
 431                 return -EINVAL;
 432         }
 433 }
 434
 435 static const struct lttng_ust_abi_objd_ops lttng_ops = {
 436         .cmd = lttng_cmd,
 437 };
 438
 439 static
 440 int lttng_abi_map_channel(int session_objd,
 441                 struct lttng_ust_abi_channel *ust_chan,
 442                 union lttng_ust_abi_args *uargs,
 443                 void *owner)
 444 {
 445         struct lttng_ust_session *session = objd_private(session_objd);
 446         const char *transport_name;
 447         struct lttng_transport *transport;
 448         const char *chan_name;
 449         int chan_objd;
 450         struct lttng_ust_shm_handle *channel_handle;
 451         struct lttng_ust_abi_channel_config *lttng_chan_config;
 452         struct lttng_channel *lttng_chan;
 453         struct lttng_ust_lib_ring_buffer_channel *chan;
 454         struct lttng_ust_lib_ring_buffer_config *config;
 455         void *chan_data;
 456         int wakeup_fd;
 457         uint64_t len;
 458         int ret;
 459         enum lttng_ust_abi_chan_type type;
 460
 461         chan_data = uargs->channel.chan_data;
 462         wakeup_fd = uargs->channel.wakeup_fd;
 463         len = ust_chan->len;
 464         type = ust_chan->type;
 465
 466         switch (type) {
 467         case LTTNG_UST_ABI_CHAN_PER_CPU:
 468                 break;
 469         default:
 470                 ret = -EINVAL;
 471                 goto invalid;
 472         }
 473
 474         if (session->priv->been_active) {
 475                 ret = -EBUSY;
 476                 goto active;    /* Refuse to add channel to active session */
 477         }
 478
 479         lttng_chan = zmalloc(sizeof(struct lttng_channel));
 480         if (!lttng_chan) {
 481                 ret = -ENOMEM;
 482                 goto lttng_chan_error;
 483         }
 484
 485         channel_handle = channel_handle_create(chan_data, len, wakeup_fd);
 486         if (!channel_handle) {
 487                 ret = -EINVAL;
 488                 goto handle_error;
 489         }
 490
 491         /* Ownership of chan_data and wakeup_fd taken by channel handle. */
 492         uargs->channel.chan_data = NULL;
 493         uargs->channel.wakeup_fd = -1;
 494
 495         chan = shmp(channel_handle, channel_handle->chan);
 496         assert(chan);
 497         chan->handle = channel_handle;
 498         config = &chan->backend.config;
 499         lttng_chan_config = channel_get_private_config(chan);
 500         if (!lttng_chan_config) {
 501                 ret = -EINVAL;
 502                 goto alloc_error;
 503         }
 504
 505         /* Lookup transport name */
 506         switch (type) {
 507         case LTTNG_UST_ABI_CHAN_PER_CPU:
 508                 if (config->output == RING_BUFFER_MMAP) {
 509                         if (config->mode == RING_BUFFER_OVERWRITE) {
 510                                 if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER) {
 511                                         transport_name = "relay-overwrite-mmap";
 512                                 } else {
 513                                         transport_name = "relay-overwrite-rt-mmap";
 514                                 }
 515                         } else {
 516                                 if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER) {
 517                                         transport_name = "relay-discard-mmap";
 518                                 } else {
 519                                         transport_name = "relay-discard-rt-mmap";
 520                                 }
 521                         }
 522                 } else {
 523                         ret = -EINVAL;
 524                         goto notransport;
 525                 }
 526                 chan_name = "channel";
 527                 break;
 528         default:
 529                 ret = -EINVAL;
 530                 goto notransport;
 531         }
 532         transport = lttng_ust_transport_find(transport_name);
 533         if (!transport) {
 534                 DBG("LTTng transport %s not found\n",
 535                        transport_name);
 536                 ret = -EINVAL;
 537                 goto notransport;
 538         }
 539
 540         chan_objd = objd_alloc(NULL, &lttng_channel_ops, owner, chan_name);
 541         if (chan_objd < 0) {
 542                 ret = chan_objd;
 543                 goto objd_error;
 544         }
 545
 546         /* Initialize our lttng chan */
 547         lttng_chan->chan = chan;
 548         lttng_chan->tstate = 1;
 549         lttng_chan->enabled = 1;
 550         lttng_chan->ctx = NULL;
 551         lttng_chan->session = session;
 552         lttng_chan->ops = &transport->ops;
 553         memcpy(&lttng_chan->chan->backend.config,
 554                 transport->client_config,
 555                 sizeof(lttng_chan->chan->backend.config));
 556         cds_list_add(&lttng_chan->node, &session->priv->chan_head);
 557         lttng_chan->header_type = 0;
 558         lttng_chan->handle = channel_handle;
 559         lttng_chan->type = type;
 560         /* Copy fields from lttng ust chan config. */
 561         lttng_chan->id = lttng_chan_config->id;
 562         memcpy(lttng_chan->uuid, lttng_chan_config->uuid, LTTNG_UST_UUID_LEN);
 563         channel_set_private(chan, lttng_chan);
 564
 565         /*
 566          * We tolerate no failure path after channel creation. It will stay
 567          * invariant for the rest of the session.
 568          */
 569         objd_set_private(chan_objd, lttng_chan);
 570         lttng_chan->objd = chan_objd;
 571         /* The channel created holds a reference on the session */
 572         objd_ref(session_objd);
 573         return chan_objd;
 574
 575         /* error path after channel was created */
 576 objd_error:
 577 notransport:
 578 alloc_error:
 579         channel_destroy(chan, channel_handle, 0);
 580         free(lttng_chan);
 581         return ret;
 582
 583 handle_error:
 584         free(lttng_chan);
 585 lttng_chan_error:
 586 active:
 587 invalid:
 588         return ret;
 589 }
 590
 591 /**
 592  *      lttng_session_cmd - lttng session object command
 593  *
 594  *      @obj: the object
 595  *      @cmd: the command
 596  *      @arg: command arg
 597  *      @uargs: UST arguments (internal)
 598  *      @owner: objd owner
 599  *
 600  *      This descriptor implements lttng commands:
 601  *      LTTNG_UST_ABI_CHANNEL
 602  *              Returns a LTTng channel object descriptor
 603  *      LTTNG_UST_ABI_ENABLE
 604  *              Enables tracing for a session (weak enable)
 605  *      LTTNG_UST_ABI_DISABLE
 606  *              Disables tracing for a session (strong disable)
 607  *
 608  * The returned channel will be deleted when its file descriptor is closed.
 609  */
 610 static
 611 long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg,
 612         union lttng_ust_abi_args *uargs, void *owner)
 613 {
 614         struct lttng_ust_session *session = objd_private(objd);
 615
 616         switch (cmd) {
 617         case LTTNG_UST_ABI_CHANNEL:
 618                 return lttng_abi_map_channel(objd,
 619                                 (struct lttng_ust_abi_channel *) arg,
 620                                 uargs, owner);
 621         case LTTNG_UST_ABI_SESSION_START:
 622         case LTTNG_UST_ABI_ENABLE:
 623                 return lttng_session_enable(session);
 624         case LTTNG_UST_ABI_SESSION_STOP:
 625         case LTTNG_UST_ABI_DISABLE:
 626                 return lttng_session_disable(session);
 627         case LTTNG_UST_ABI_SESSION_STATEDUMP:
 628                 return lttng_session_statedump(session);
 629         case LTTNG_UST_ABI_COUNTER:
 630         case LTTNG_UST_ABI_COUNTER_GLOBAL:
 631         case LTTNG_UST_ABI_COUNTER_CPU:
 632                 /* Not implemented yet. */
 633                 return -EINVAL;
 634         default:
 635                 return -EINVAL;
 636         }
 637 }
 638
 639 /*
 640  * Called when the last file reference is dropped.
 641  *
 642  * Big fat note: channels and events are invariant for the whole session after
 643  * their creation. So this session destruction also destroys all channel and
 644  * event structures specific to this session (they are not destroyed when their
 645  * individual file is released).
 646  */
 647 static
 648 int lttng_release_session(int objd)
 649 {
 650         struct lttng_ust_session *session = objd_private(objd);
 651
 652         if (session) {
 653                 lttng_session_destroy(session);
 654                 return 0;
 655         } else {
 656                 return -EINVAL;
 657         }
 658 }
 659
 660 static const struct lttng_ust_abi_objd_ops lttng_session_ops = {
 661         .release = lttng_release_session,
 662         .cmd = lttng_session_cmd,
 663 };
 664
 665 static int lttng_ust_event_notifier_enabler_create(int event_notifier_group_obj,
 666                 void *owner, struct lttng_ust_abi_event_notifier *event_notifier_param,
 667                 enum lttng_enabler_format_type type)
 668 {
 669         struct lttng_event_notifier_group *event_notifier_group =
 670                 objd_private(event_notifier_group_obj);
 671         struct lttng_event_notifier_enabler *event_notifier_enabler;
 672         int event_notifier_objd, ret;
 673
 674         event_notifier_param->event.name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
 675         event_notifier_objd = objd_alloc(NULL, &lttng_event_notifier_enabler_ops, owner,
 676                 "event_notifier enabler");
 677         if (event_notifier_objd < 0) {
 678                 ret = event_notifier_objd;
 679                 goto objd_error;
 680         }
 681
 682         event_notifier_enabler = lttng_event_notifier_enabler_create(
 683                 event_notifier_group, type, event_notifier_param);
 684         if (!event_notifier_enabler) {
 685                 ret = -ENOMEM;
 686                 goto event_notifier_error;
 687         }
 688
 689         objd_set_private(event_notifier_objd, event_notifier_enabler);
 690         /* The event_notifier holds a reference on the event_notifier group. */
 691         objd_ref(event_notifier_enabler->group->objd);
 692
 693         return event_notifier_objd;
 694
 695 event_notifier_error:
 696         {
 697                 int err;
 698
 699                 err = lttng_ust_abi_objd_unref(event_notifier_objd, 1);
 700                 assert(!err);
 701         }
 702 objd_error:
 703         return ret;
 704 }
 705
 706 static
 707 long lttng_event_notifier_enabler_cmd(int objd, unsigned int cmd, unsigned long arg,
 708                 union lttng_ust_abi_args *uargs, void *owner)
 709 {
 710         struct lttng_event_notifier_enabler *event_notifier_enabler = objd_private(objd);
 711         switch (cmd) {
 712         case LTTNG_UST_ABI_FILTER:
 713                 return lttng_event_notifier_enabler_attach_filter_bytecode(
 714                         event_notifier_enabler,
 715                         (struct lttng_ust_bytecode_node **) arg);
 716         case LTTNG_UST_ABI_EXCLUSION:
 717                 return lttng_event_notifier_enabler_attach_exclusion(event_notifier_enabler,
 718                         (struct lttng_ust_excluder_node **) arg);
 719         case LTTNG_UST_ABI_CAPTURE:
 720                 return lttng_event_notifier_enabler_attach_capture_bytecode(
 721                         event_notifier_enabler,
 722                         (struct lttng_ust_bytecode_node **) arg);
 723         case LTTNG_UST_ABI_ENABLE:
 724                 return lttng_event_notifier_enabler_enable(event_notifier_enabler);
 725         case LTTNG_UST_ABI_DISABLE:
 726                 return lttng_event_notifier_enabler_disable(event_notifier_enabler);
 727         default:
 728                 return -EINVAL;
 729         }
 730 }
 731
 732 /**
 733  *      lttng_event_notifier_group_error_counter_cmd - lttng event_notifier group error counter object command
 734  *
 735  *      @obj: the object
 736  *      @cmd: the command
 737  *      @arg: command arg
 738  *      @uargs: UST arguments (internal)
 739  *      @owner: objd owner
 740  *
 741  *      This descriptor implements lttng commands:
 742  *      LTTNG_UST_ABI_COUNTER_GLOBAL
 743  *        Return negative error code on error, 0 on success.
 744  *      LTTNG_UST_ABI_COUNTER_CPU
 745  *        Return negative error code on error, 0 on success.
 746  */
 747 static
 748 long lttng_event_notifier_group_error_counter_cmd(int objd, unsigned int cmd, unsigned long arg,
 749         union lttng_ust_abi_args *uargs, void *owner)
 750 {
 751         int ret;
 752         struct lttng_counter *counter = objd_private(objd);
 753
 754         switch (cmd) {
 755         case LTTNG_UST_ABI_COUNTER_GLOBAL:
 756                 ret = -EINVAL;  /* Unimplemented. */
 757                 break;
 758         case LTTNG_UST_ABI_COUNTER_CPU:
 759         {
 760                 struct lttng_ust_abi_counter_cpu *counter_cpu =
 761                         (struct lttng_ust_abi_counter_cpu *)arg;
 762
 763                 ret = lttng_counter_set_cpu_shm(counter->counter,
 764                         counter_cpu->cpu_nr, uargs->counter_shm.shm_fd);
 765                 if (!ret) {
 766                         /* Take ownership of the shm_fd. */
 767                         uargs->counter_shm.shm_fd = -1;
 768                 }
 769                 break;
 770         }
 771         default:
 772                 ret = -EINVAL;
 773                 break;
 774         }
 775
 776         return ret;
 777 }
 778
 779 __attribute__((visibility("hidden")))
 780 int lttng_release_event_notifier_group_error_counter(int objd)
 781 {
 782         struct lttng_counter *counter = objd_private(objd);
 783
 784         if (counter) {
 785                 return lttng_ust_abi_objd_unref(counter->event_notifier_group->objd, 0);
 786         } else {
 787                 return -EINVAL;
 788         }
 789 }
 790
 791 static const struct lttng_ust_abi_objd_ops lttng_event_notifier_group_error_counter_ops = {
 792         .release = lttng_release_event_notifier_group_error_counter,
 793         .cmd = lttng_event_notifier_group_error_counter_cmd,
 794 };
 795
 796 static
 797 int lttng_ust_event_notifier_group_create_error_counter(int event_notifier_group_objd, void *owner,
 798                 struct lttng_ust_abi_counter_conf *error_counter_conf)
 799 {
 800         const char *counter_transport_name;
 801         struct lttng_event_notifier_group *event_notifier_group =
 802                 objd_private(event_notifier_group_objd);
 803         struct lttng_counter *counter;
 804         int counter_objd, ret;
 805         struct lttng_counter_dimension dimensions[1];
 806         size_t counter_len;
 807
 808         if (event_notifier_group->error_counter)
 809                 return -EBUSY;
 810
 811         if (error_counter_conf->arithmetic != LTTNG_UST_ABI_COUNTER_ARITHMETIC_MODULAR)
 812                 return -EINVAL;
 813
 814         if (error_counter_conf->number_dimensions != 1)
 815                 return -EINVAL;
 816
 817         switch (error_counter_conf->bitness) {
 818         case LTTNG_UST_ABI_COUNTER_BITNESS_64:
 819                 counter_transport_name = "counter-per-cpu-64-modular";
 820                 break;
 821         case LTTNG_UST_ABI_COUNTER_BITNESS_32:
 822                 counter_transport_name = "counter-per-cpu-32-modular";
 823                 break;
 824         default:
 825                 return -EINVAL;
 826         }
 827
 828         counter_objd = objd_alloc(NULL, &lttng_event_notifier_group_error_counter_ops, owner,
 829                 "event_notifier group error counter");
 830         if (counter_objd < 0) {
 831                 ret = counter_objd;
 832                 goto objd_error;
 833         }
 834
 835         counter_len = error_counter_conf->dimensions[0].size;
 836         dimensions[0].size = counter_len;
 837         dimensions[0].underflow_index = 0;
 838         dimensions[0].overflow_index = 0;
 839         dimensions[0].has_underflow = 0;
 840         dimensions[0].has_overflow = 0;
 841
 842         counter = lttng_ust_counter_create(counter_transport_name, 1, dimensions);
 843         if (!counter) {
 844                 ret = -EINVAL;
 845                 goto create_error;
 846         }
 847
 848         event_notifier_group->error_counter_len = counter_len;
 849         /*
 850          * store-release to publish error counter matches load-acquire
 851          * in record_error. Ensures the counter is created and the
 852          * error_counter_len is set before they are used.
 853          * Currently a full memory barrier is used, which could be
 854          * turned into acquire-release barriers.
 855          */
 856         cmm_smp_mb();
 857         CMM_STORE_SHARED(event_notifier_group->error_counter, counter);
 858
 859         counter->objd = counter_objd;
 860         counter->event_notifier_group = event_notifier_group;   /* owner */
 861
 862         objd_set_private(counter_objd, counter);
 863         /* The error counter holds a reference on the event_notifier group. */
 864         objd_ref(event_notifier_group->objd);
 865
 866         return counter_objd;
 867
 868 create_error:
 869         {
 870                 int err;
 871
 872                 err = lttng_ust_abi_objd_unref(counter_objd, 1);
 873                 assert(!err);
 874         }
 875 objd_error:
 876         return ret;
 877 }
 878
 879 static
 880 long lttng_event_notifier_group_cmd(int objd, unsigned int cmd, unsigned long arg,
 881                 union lttng_ust_abi_args *uargs, void *owner)
 882 {
 883         switch (cmd) {
 884         case LTTNG_UST_ABI_EVENT_NOTIFIER_CREATE:
 885         {
 886                 struct lttng_ust_abi_event_notifier *event_notifier_param =
 887                         (struct lttng_ust_abi_event_notifier *) arg;
 888                 if (strutils_is_star_glob_pattern(event_notifier_param->event.name)) {
 889                         /*
 890                          * If the event name is a star globbing pattern,
 891                          * we create the special star globbing enabler.
 892                          */
 893                         return lttng_ust_event_notifier_enabler_create(objd,
 894                                         owner, event_notifier_param,
 895                                         LTTNG_ENABLER_FORMAT_STAR_GLOB);
 896                 } else {
 897                         return lttng_ust_event_notifier_enabler_create(objd,
 898                                         owner, event_notifier_param,
 899                                         LTTNG_ENABLER_FORMAT_EVENT);
 900                 }
 901         }
 902         case LTTNG_UST_ABI_COUNTER:
 903         {
 904                 struct lttng_ust_abi_counter_conf *counter_conf =
 905                         (struct lttng_ust_abi_counter_conf *) uargs->counter.counter_data;
 906                 return lttng_ust_event_notifier_group_create_error_counter(
 907                                 objd, owner, counter_conf);
 908         }
 909         default:
 910                 return -EINVAL;
 911         }
 912 }
 913
 914 static
 915 int lttng_event_notifier_enabler_release(int objd)
 916 {
 917         struct lttng_event_notifier_enabler *event_notifier_enabler = objd_private(objd);
 918
 919         if (event_notifier_enabler)
 920                 return lttng_ust_abi_objd_unref(event_notifier_enabler->group->objd, 0);
 921         return 0;
 922 }
 923
 924 static const struct lttng_ust_abi_objd_ops lttng_event_notifier_enabler_ops = {
 925         .release = lttng_event_notifier_enabler_release,
 926         .cmd = lttng_event_notifier_enabler_cmd,
 927 };
 928
 929 static
 930 int lttng_release_event_notifier_group(int objd)
 931 {
 932         struct lttng_event_notifier_group *event_notifier_group = objd_private(objd);
 933
 934         if (event_notifier_group) {
 935                 lttng_event_notifier_group_destroy(event_notifier_group);
 936                 return 0;
 937         } else {
 938                 return -EINVAL;
 939         }
 940 }
 941
 942 static const struct lttng_ust_abi_objd_ops lttng_event_notifier_group_ops = {
 943         .release = lttng_release_event_notifier_group,
 944         .cmd = lttng_event_notifier_group_cmd,
 945 };
 946
 947 static
 948 long lttng_tracepoint_list_cmd(int objd, unsigned int cmd, unsigned long arg,
 949         union lttng_ust_abi_args *uargs, void *owner)
 950 {
 951         struct lttng_ust_tracepoint_list *list = objd_private(objd);
 952         struct lttng_ust_abi_tracepoint_iter *tp =
 953                 (struct lttng_ust_abi_tracepoint_iter *) arg;
 954         struct lttng_ust_abi_tracepoint_iter *iter;
 955
 956         switch (cmd) {
 957         case LTTNG_UST_ABI_TRACEPOINT_LIST_GET:
 958         {
 959                 iter = lttng_ust_tracepoint_list_get_iter_next(list);
 960                 if (!iter)
 961                         return -LTTNG_UST_ERR_NOENT;
 962                 memcpy(tp, iter, sizeof(*tp));
 963                 return 0;
 964         }
 965         default:
 966                 return -EINVAL;
 967         }
 968 }
 969
 970 static
 971 int lttng_abi_tracepoint_list(void *owner)
 972 {
 973         int list_objd, ret;
 974         struct lttng_ust_tracepoint_list *list;
 975
 976         list_objd = objd_alloc(NULL, &lttng_tracepoint_list_ops, owner, "tp_list");
 977         if (list_objd < 0) {
 978                 ret = list_objd;
 979                 goto objd_error;
 980         }
 981         list = zmalloc(sizeof(*list));
 982         if (!list) {
 983                 ret = -ENOMEM;
 984                 goto alloc_error;
 985         }
 986         objd_set_private(list_objd, list);
 987
 988         /* populate list by walking on all registered probes. */
 989         ret = lttng_probes_get_event_list(list);
 990         if (ret) {
 991                 goto list_error;
 992         }
 993         return list_objd;
 994
 995 list_error:
 996         free(list);
 997 alloc_error:
 998         {
 999                 int err;
1000
1001                 err = lttng_ust_abi_objd_unref(list_objd, 1);
1002                 assert(!err);
1003         }
1004 objd_error:
1005         return ret;
1006 }
1007
1008 static
1009 int lttng_release_tracepoint_list(int objd)
1010 {
1011         struct lttng_ust_tracepoint_list *list = objd_private(objd);
1012
1013         if (list) {
1014                 lttng_probes_prune_event_list(list);
1015                 free(list);
1016                 return 0;
1017         } else {
1018                 return -EINVAL;
1019         }
1020 }
1021
1022 static const struct lttng_ust_abi_objd_ops lttng_tracepoint_list_ops = {
1023         .release = lttng_release_tracepoint_list,
1024         .cmd = lttng_tracepoint_list_cmd,
1025 };
1026
1027 static
1028 long lttng_tracepoint_field_list_cmd(int objd, unsigned int cmd,
1029         unsigned long arg, union lttng_ust_abi_args *uargs, void *owner)
1030 {
1031         struct lttng_ust_field_list *list = objd_private(objd);
1032         struct lttng_ust_abi_field_iter *tp = &uargs->field_list.entry;
1033         struct lttng_ust_abi_field_iter *iter;
1034
1035         switch (cmd) {
1036         case LTTNG_UST_ABI_TRACEPOINT_FIELD_LIST_GET:
1037         {
1038                 iter = lttng_ust_field_list_get_iter_next(list);
1039                 if (!iter)
1040                         return -LTTNG_UST_ERR_NOENT;
1041                 memcpy(tp, iter, sizeof(*tp));
1042                 return 0;
1043         }
1044         default:
1045                 return -EINVAL;
1046         }
1047 }
1048
1049 static
1050 int lttng_abi_tracepoint_field_list(void *owner)
1051 {
1052         int list_objd, ret;
1053         struct lttng_ust_field_list *list;
1054
1055         list_objd = objd_alloc(NULL, &lttng_tracepoint_field_list_ops, owner,
1056                         "tp_field_list");
1057         if (list_objd < 0) {
1058                 ret = list_objd;
1059                 goto objd_error;
1060         }
1061         list = zmalloc(sizeof(*list));
1062         if (!list) {
1063                 ret = -ENOMEM;
1064                 goto alloc_error;
1065         }
1066         objd_set_private(list_objd, list);
1067
1068         /* populate list by walking on all registered probes. */
1069         ret = lttng_probes_get_field_list(list);
1070         if (ret) {
1071                 goto list_error;
1072         }
1073         return list_objd;
1074
1075 list_error:
1076         free(list);
1077 alloc_error:
1078         {
1079                 int err;
1080
1081                 err = lttng_ust_abi_objd_unref(list_objd, 1);
1082                 assert(!err);
1083         }
1084 objd_error:
1085         return ret;
1086 }
1087
1088 static
1089 int lttng_release_tracepoint_field_list(int objd)
1090 {
1091         struct lttng_ust_field_list *list = objd_private(objd);
1092
1093         if (list) {
1094                 lttng_probes_prune_field_list(list);
1095                 free(list);
1096                 return 0;
1097         } else {
1098                 return -EINVAL;
1099         }
1100 }
1101
1102 static const struct lttng_ust_abi_objd_ops lttng_tracepoint_field_list_ops = {
1103         .release = lttng_release_tracepoint_field_list,
1104         .cmd = lttng_tracepoint_field_list_cmd,
1105 };
1106
1107 static
1108 int lttng_abi_map_stream(int channel_objd, struct lttng_ust_abi_stream *info,
1109                 union lttng_ust_abi_args *uargs, void *owner)
1110 {
1111         struct lttng_channel *channel = objd_private(channel_objd);
1112         int ret;
1113
1114         ret = channel_handle_add_stream(channel->handle,
1115                 uargs->stream.shm_fd, uargs->stream.wakeup_fd,
1116                 info->stream_nr, info->len);
1117         if (ret)
1118                 goto error_add_stream;
1119         /* Take ownership of shm_fd and wakeup_fd. */
1120         uargs->stream.shm_fd = -1;
1121         uargs->stream.wakeup_fd = -1;
1122
1123         return 0;
1124
1125 error_add_stream:
1126         return ret;
1127 }
1128
1129 static
1130 int lttng_abi_create_event_enabler(int channel_objd,
1131                            struct lttng_ust_abi_event *event_param,
1132                            void *owner,
1133                            enum lttng_enabler_format_type format_type)
1134 {
1135         struct lttng_channel *channel = objd_private(channel_objd);
1136         struct lttng_event_enabler *enabler;
1137         int event_objd, ret;
1138
1139         event_param->name[LTTNG_UST_ABI_SYM_NAME_LEN - 1] = '\0';
1140         event_objd = objd_alloc(NULL, &lttng_event_enabler_ops, owner,
1141                 "event enabler");
1142         if (event_objd < 0) {
1143                 ret = event_objd;
1144                 goto objd_error;
1145         }
1146         /*
1147          * We tolerate no failure path after event creation. It will stay
1148          * invariant for the rest of the session.
1149          */
1150         enabler = lttng_event_enabler_create(format_type, event_param, channel);
1151         if (!enabler) {
1152                 ret = -ENOMEM;
1153                 goto event_error;
1154         }
1155         objd_set_private(event_objd, enabler);
1156         /* The event holds a reference on the channel */
1157         objd_ref(channel_objd);
1158         return event_objd;
1159
1160 event_error:
1161         {
1162                 int err;
1163
1164                 err = lttng_ust_abi_objd_unref(event_objd, 1);
1165                 assert(!err);
1166         }
1167 objd_error:
1168         return ret;
1169 }
1170
1171 /**
1172  *      lttng_channel_cmd - lttng control through object descriptors
1173  *
1174  *      @objd: the object descriptor
1175  *      @cmd: the command
1176  *      @arg: command arg
1177  *      @uargs: UST arguments (internal)
1178  *      @owner: objd owner
1179  *
1180  *      This object descriptor implements lttng commands:
1181  *      LTTNG_UST_ABI_STREAM
1182  *              Returns an event stream object descriptor or failure.
1183  *              (typically, one event stream records events from one CPU)
1184  *      LTTNG_UST_ABI_EVENT
1185  *              Returns an event object descriptor or failure.
1186  *      LTTNG_UST_ABI_CONTEXT
1187  *              Prepend a context field to each event in the channel
1188  *      LTTNG_UST_ABI_ENABLE
1189  *              Enable recording for events in this channel (weak enable)
1190  *      LTTNG_UST_ABI_DISABLE
1191  *              Disable recording for events in this channel (strong disable)
1192  *
1193  * Channel and event file descriptors also hold a reference on the session.
1194  */
1195 static
1196 long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg,
1197         union lttng_ust_abi_args *uargs, void *owner)
1198 {
1199         struct lttng_channel *channel = objd_private(objd);
1200
1201         if (cmd != LTTNG_UST_ABI_STREAM) {
1202                 /*
1203                  * Check if channel received all streams.
1204                  */
1205                 if (!lttng_is_channel_ready(channel))
1206                         return -EPERM;
1207         }
1208
1209         switch (cmd) {
1210         case LTTNG_UST_ABI_STREAM:
1211         {
1212                 struct lttng_ust_abi_stream *stream;
1213
1214                 stream = (struct lttng_ust_abi_stream *) arg;
1215                 /* stream used as output */
1216                 return lttng_abi_map_stream(objd, stream, uargs, owner);
1217         }
1218         case LTTNG_UST_ABI_EVENT:
1219         {
1220                 struct lttng_ust_abi_event *event_param =
1221                         (struct lttng_ust_abi_event *) arg;
1222
1223                 if (strutils_is_star_glob_pattern(event_param->name)) {
1224                         /*
1225                          * If the event name is a star globbing pattern,
1226                          * we create the special star globbing enabler.
1227                          */
1228                         return lttng_abi_create_event_enabler(objd, event_param,
1229                                         owner, LTTNG_ENABLER_FORMAT_STAR_GLOB);
1230                 } else {
1231                         return lttng_abi_create_event_enabler(objd, event_param,
1232                                         owner, LTTNG_ENABLER_FORMAT_EVENT);
1233                 }
1234         }
1235         case LTTNG_UST_ABI_CONTEXT:
1236                 return lttng_abi_add_context(objd,
1237                                 (struct lttng_ust_abi_context *) arg, uargs,
1238                                 &channel->ctx, channel->session);
1239         case LTTNG_UST_ABI_ENABLE:
1240                 return lttng_channel_enable(channel);
1241         case LTTNG_UST_ABI_DISABLE:
1242                 return lttng_channel_disable(channel);
1243         case LTTNG_UST_ABI_FLUSH_BUFFER:
1244                 return channel->ops->priv->flush_buffer(channel->chan, channel->handle);
1245         default:
1246                 return -EINVAL;
1247         }
1248 }
1249
1250 static
1251 int lttng_channel_release(int objd)
1252 {
1253         struct lttng_channel *channel = objd_private(objd);
1254
1255         if (channel)
1256                 return lttng_ust_abi_objd_unref(channel->session->priv->objd, 0);
1257         return 0;
1258 }
1259
1260 static const struct lttng_ust_abi_objd_ops lttng_channel_ops = {
1261         .release = lttng_channel_release,
1262         .cmd = lttng_channel_cmd,
1263 };
1264
1265 /**
1266  *      lttng_enabler_cmd - lttng control through object descriptors
1267  *
1268  *      @objd: the object descriptor
1269  *      @cmd: the command
1270  *      @arg: command arg
1271  *      @uargs: UST arguments (internal)
1272  *      @owner: objd owner
1273  *
1274  *      This object descriptor implements lttng commands:
1275  *      LTTNG_UST_ABI_CONTEXT
1276  *              Prepend a context field to each record of events of this
1277  *              enabler.
1278  *      LTTNG_UST_ABI_ENABLE
1279  *              Enable recording for this enabler
1280  *      LTTNG_UST_ABI_DISABLE
1281  *              Disable recording for this enabler
1282  *      LTTNG_UST_ABI_FILTER
1283  *              Attach a filter to an enabler.
1284  *      LTTNG_UST_ABI_EXCLUSION
1285  *              Attach exclusions to an enabler.
1286  */
1287 static
1288 long lttng_event_enabler_cmd(int objd, unsigned int cmd, unsigned long arg,
1289         union lttng_ust_abi_args *uargs, void *owner)
1290 {
1291         struct lttng_event_enabler *enabler = objd_private(objd);
1292
1293         switch (cmd) {
1294         case LTTNG_UST_ABI_CONTEXT:
1295                 return lttng_event_enabler_attach_context(enabler,
1296                                 (struct lttng_ust_abi_context *) arg);
1297         case LTTNG_UST_ABI_ENABLE:
1298                 return lttng_event_enabler_enable(enabler);
1299         case LTTNG_UST_ABI_DISABLE:
1300                 return lttng_event_enabler_disable(enabler);
1301         case LTTNG_UST_ABI_FILTER:
1302         {
1303                 int ret;
1304
1305                 ret = lttng_event_enabler_attach_filter_bytecode(enabler,
1306                                 (struct lttng_ust_bytecode_node **) arg);
1307                 if (ret)
1308                         return ret;
1309                 return 0;
1310         }
1311         case LTTNG_UST_ABI_EXCLUSION:
1312         {
1313                 return lttng_event_enabler_attach_exclusion(enabler,
1314                                 (struct lttng_ust_excluder_node **) arg);
1315         }
1316         default:
1317                 return -EINVAL;
1318         }
1319 }
1320
1321 static
1322 int lttng_event_enabler_release(int objd)
1323 {
1324         struct lttng_event_enabler *event_enabler = objd_private(objd);
1325
1326         if (event_enabler)
1327                 return lttng_ust_abi_objd_unref(event_enabler->chan->objd, 0);
1328
1329         return 0;
1330 }
1331
1332 static const struct lttng_ust_abi_objd_ops lttng_event_enabler_ops = {
1333         .release = lttng_event_enabler_release,
1334         .cmd = lttng_event_enabler_cmd,
1335 };
1336
1337 void lttng_ust_abi_exit(void)
1338 {
1339         lttng_ust_abi_close_in_progress = 1;
1340         ust_lock_nocheck();
1341         objd_table_destroy();
1342         ust_unlock();
1343         lttng_ust_abi_close_in_progress = 0;
1344 }