liblttng-ust/lttng-ust-abi.c

   1 /*
   2  * lttng-ust-abi.c
   3  *
   4  * LTTng UST ABI
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  *
  22  *
  23  * Mimic system calls for:
  24  * - session creation, returns an object descriptor or failure.
  25  *   - channel creation, returns an object descriptor or failure.
  26  *     - Operates on a session object descriptor
  27  *     - Takes all channel options as parameters.
  28  *   - stream get, returns an object descriptor or failure.
  29  *     - Operates on a channel object descriptor.
  30  *   - stream notifier get, returns an object descriptor or failure.
  31  *     - Operates on a channel object descriptor.
  32  *   - event creation, returns an object descriptor or failure.
  33  *     - Operates on a channel object descriptor
  34  *     - Takes an event name as parameter
  35  *     - Takes an instrumentation source as parameter
  36  *       - e.g. tracepoints, dynamic_probes...
  37  *     - Takes instrumentation source specific arguments.
  38  */
  39
  40 #define _LGPL_SOURCE
  41 #include <fcntl.h>
  42 #include <stdint.h>
  43 #include <unistd.h>
  44
  45 #include <urcu/compiler.h>
  46 #include <urcu/list.h>
  47
  48 #include <helper.h>
  49 #include <lttng/tracepoint.h>
  50 #include <lttng/ust-abi.h>
  51 #include <lttng/ust-error.h>
  52 #include <lttng/ust-events.h>
  53 #include <lttng/ust-version.h>
  54 #include <ust-fd.h>
  55 #include <usterr-signal-safe.h>
  56
  57 #include "../libringbuffer/frontend_types.h"
  58 #include "../libringbuffer/shm.h"
  59 #include "../libcounter/counter.h"
  60 #include "lttng-tracer.h"
  61 #include "string-utils.h"
  62 #include "ust-events-internal.h"
  63
  64 #define OBJ_NAME_LEN    16
  65
  66 static int lttng_ust_abi_close_in_progress;
  67
  68 static
  69 int lttng_abi_tracepoint_list(void *owner);
  70 static
  71 int lttng_abi_tracepoint_field_list(void *owner);
  72
  73 /*
  74  * Object descriptor table. Should be protected from concurrent access
  75  * by the caller.
  76  */
  77
  78 struct lttng_ust_obj {
  79         union {
  80                 struct {
  81                         void *private_data;
  82                         const struct lttng_ust_objd_ops *ops;
  83                         int f_count;
  84                         int owner_ref;  /* has ref from owner */
  85                         void *owner;
  86                         char name[OBJ_NAME_LEN];
  87                 } s;
  88                 int freelist_next;      /* offset freelist. end is -1. */
  89         } u;
  90 };
  91
  92 struct lttng_ust_objd_table {
  93         struct lttng_ust_obj *array;
  94         unsigned int len, allocated_len;
  95         int freelist_head;              /* offset freelist head. end is -1 */
  96 };
  97
  98 static struct lttng_ust_objd_table objd_table = {
  99         .freelist_head = -1,
 100 };
 101
 102 static
 103 int objd_alloc(void *private_data, const struct lttng_ust_objd_ops *ops,
 104                 void *owner, const char *name)
 105 {
 106         struct lttng_ust_obj *obj;
 107
 108         if (objd_table.freelist_head != -1) {
 109                 obj = &objd_table.array[objd_table.freelist_head];
 110                 objd_table.freelist_head = obj->u.freelist_next;
 111                 goto end;
 112         }
 113
 114         if (objd_table.len >= objd_table.allocated_len) {
 115                 unsigned int new_allocated_len, old_allocated_len;
 116                 struct lttng_ust_obj *new_table, *old_table;
 117
 118                 old_allocated_len = objd_table.allocated_len;
 119                 old_table = objd_table.array;
 120                 if (!old_allocated_len)
 121                         new_allocated_len = 1;
 122                 else
 123                         new_allocated_len = old_allocated_len << 1;
 124                 new_table = zmalloc(sizeof(struct lttng_ust_obj) * new_allocated_len);
 125                 if (!new_table)
 126                         return -ENOMEM;
 127                 memcpy(new_table, old_table,
 128                        sizeof(struct lttng_ust_obj) * old_allocated_len);
 129                 free(old_table);
 130                 objd_table.array = new_table;
 131                 objd_table.allocated_len = new_allocated_len;
 132         }
 133         obj = &objd_table.array[objd_table.len];
 134         objd_table.len++;
 135 end:
 136         obj->u.s.private_data = private_data;
 137         obj->u.s.ops = ops;
 138         obj->u.s.f_count = 2;   /* count == 1 : object is allocated */
 139                                 /* count == 2 : allocated + hold ref */
 140         obj->u.s.owner_ref = 1; /* One owner reference */
 141         obj->u.s.owner = owner;
 142         strncpy(obj->u.s.name, name, OBJ_NAME_LEN);
 143         obj->u.s.name[OBJ_NAME_LEN - 1] = '\0';
 144         return obj - objd_table.array;
 145 }
 146
 147 static
 148 struct lttng_ust_obj *_objd_get(int id)
 149 {
 150         if (id >= objd_table.len)
 151                 return NULL;
 152         if (!objd_table.array[id].u.s.f_count)
 153                 return NULL;
 154         return &objd_table.array[id];
 155 }
 156
 157 static
 158 void *objd_private(int id)
 159 {
 160         struct lttng_ust_obj *obj = _objd_get(id);
 161         assert(obj);
 162         return obj->u.s.private_data;
 163 }
 164
 165 static
 166 void objd_set_private(int id, void *private_data)
 167 {
 168         struct lttng_ust_obj *obj = _objd_get(id);
 169         assert(obj);
 170         obj->u.s.private_data = private_data;
 171 }
 172
 173 const struct lttng_ust_objd_ops *objd_ops(int id)
 174 {
 175         struct lttng_ust_obj *obj = _objd_get(id);
 176
 177         if (!obj)
 178                 return NULL;
 179         return obj->u.s.ops;
 180 }
 181
 182 static
 183 void objd_free(int id)
 184 {
 185         struct lttng_ust_obj *obj = _objd_get(id);
 186
 187         assert(obj);
 188         obj->u.freelist_next = objd_table.freelist_head;
 189         objd_table.freelist_head = obj - objd_table.array;
 190         assert(obj->u.s.f_count == 1);
 191         obj->u.s.f_count = 0;   /* deallocated */
 192 }
 193
 194 static
 195 void objd_ref(int id)
 196 {
 197         struct lttng_ust_obj *obj = _objd_get(id);
 198         assert(obj != NULL);
 199         obj->u.s.f_count++;
 200 }
 201
 202 int lttng_ust_objd_unref(int id, int is_owner)
 203 {
 204         struct lttng_ust_obj *obj = _objd_get(id);
 205
 206         if (!obj)
 207                 return -EINVAL;
 208         if (obj->u.s.f_count == 1) {
 209                 ERR("Reference counting error\n");
 210                 return -EINVAL;
 211         }
 212         if (is_owner) {
 213                 if (!obj->u.s.owner_ref) {
 214                         ERR("Error decrementing owner reference");
 215                         return -EINVAL;
 216                 }
 217                 obj->u.s.owner_ref--;
 218         }
 219         if ((--obj->u.s.f_count) == 1) {
 220                 const struct lttng_ust_objd_ops *ops = objd_ops(id);
 221
 222                 if (ops->release)
 223                         ops->release(id);
 224                 objd_free(id);
 225         }
 226         return 0;
 227 }
 228
 229 static
 230 void objd_table_destroy(void)
 231 {
 232         int i;
 233
 234         for (i = 0; i < objd_table.allocated_len; i++) {
 235                 struct lttng_ust_obj *obj;
 236
 237                 obj = _objd_get(i);
 238                 if (!obj)
 239                         continue;
 240                 if (!obj->u.s.owner_ref)
 241                         continue;       /* only unref owner ref. */
 242                 (void) lttng_ust_objd_unref(i, 1);
 243         }
 244         free(objd_table.array);
 245         objd_table.array = NULL;
 246         objd_table.len = 0;
 247         objd_table.allocated_len = 0;
 248         objd_table.freelist_head = -1;
 249 }
 250
 251 const char *lttng_ust_obj_get_name(int id)
 252 {
 253         struct lttng_ust_obj *obj = _objd_get(id);
 254
 255         if (!obj)
 256                 return NULL;
 257         return obj->u.s.name;
 258 }
 259
 260 void lttng_ust_objd_table_owner_cleanup(void *owner)
 261 {
 262         int i;
 263
 264         for (i = 0; i < objd_table.allocated_len; i++) {
 265                 struct lttng_ust_obj *obj;
 266
 267                 obj = _objd_get(i);
 268                 if (!obj)
 269                         continue;
 270                 if (!obj->u.s.owner)
 271                         continue;       /* skip root handles */
 272                 if (!obj->u.s.owner_ref)
 273                         continue;       /* only unref owner ref. */
 274                 if (obj->u.s.owner == owner)
 275                         (void) lttng_ust_objd_unref(i, 1);
 276         }
 277 }
 278
 279 /*
 280  * This is LTTng's own personal way to create an ABI for sessiond.
 281  * We send commands over a socket.
 282  */
 283
 284 static const struct lttng_ust_objd_ops lttng_ops;
 285 static const struct lttng_ust_objd_ops lttng_trigger_group_ops;
 286 static const struct lttng_ust_objd_ops lttng_session_ops;
 287 static const struct lttng_ust_objd_ops lttng_channel_ops;
 288 static const struct lttng_ust_objd_ops lttng_event_enabler_ops;
 289 static const struct lttng_ust_objd_ops lttng_trigger_enabler_ops;
 290 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops;
 291 static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops;
 292
 293 int lttng_abi_create_root_handle(void)
 294 {
 295         int root_handle;
 296
 297         /* root handles have NULL owners */
 298         root_handle = objd_alloc(NULL, &lttng_ops, NULL, "root");
 299         return root_handle;
 300 }
 301
 302 static
 303 int lttng_is_channel_ready(struct lttng_channel *lttng_chan)
 304 {
 305         struct channel *chan;
 306         unsigned int nr_streams, exp_streams;
 307
 308         chan = lttng_chan->chan;
 309         nr_streams = channel_handle_get_nr_streams(lttng_chan->handle);
 310         exp_streams = chan->nr_streams;
 311         return nr_streams == exp_streams;
 312 }
 313
 314 static
 315 int lttng_abi_create_session(void *owner)
 316 {
 317         struct lttng_session *session;
 318         int session_objd, ret;
 319
 320         session = lttng_session_create();
 321         if (!session)
 322                 return -ENOMEM;
 323         session_objd = objd_alloc(session, &lttng_session_ops, owner, "session");
 324         if (session_objd < 0) {
 325                 ret = session_objd;
 326                 goto objd_error;
 327         }
 328         session->objd = session_objd;
 329         session->owner = owner;
 330         return session_objd;
 331
 332 objd_error:
 333         lttng_session_destroy(session);
 334         return ret;
 335 }
 336
 337 static
 338 long lttng_abi_tracer_version(int objd,
 339         struct lttng_ust_tracer_version *v)
 340 {
 341         v->major = LTTNG_UST_MAJOR_VERSION;
 342         v->minor = LTTNG_UST_MINOR_VERSION;
 343         v->patchlevel = LTTNG_UST_PATCHLEVEL_VERSION;
 344         return 0;
 345 }
 346
 347 static
 348 int lttng_abi_trigger_send_fd(void *owner, int trigger_notif_fd)
 349 {
 350         struct lttng_trigger_group *trigger_group;
 351         int trigger_group_objd, ret, fd_flag, close_ret;
 352
 353         trigger_group = lttng_trigger_group_create();
 354         if (!trigger_group)
 355                 return -ENOMEM;
 356
 357         /*
 358          * Set this file descriptor as NON-BLOCKING.
 359          */
 360         fd_flag = fcntl(trigger_notif_fd, F_GETFL);
 361
 362         fd_flag |= O_NONBLOCK;
 363
 364         ret = fcntl(trigger_notif_fd, F_SETFL, fd_flag);
 365         if (ret) {
 366                 ret = -errno;
 367                 goto fd_error;
 368         }
 369
 370         trigger_group_objd = objd_alloc(trigger_group,
 371                 &lttng_trigger_group_ops, owner, "trigger_group");
 372         if (trigger_group_objd < 0) {
 373                 ret = trigger_group_objd;
 374                 goto objd_error;
 375         }
 376
 377         trigger_group->objd = trigger_group_objd;
 378         trigger_group->owner = owner;
 379         trigger_group->notification_fd = trigger_notif_fd;
 380
 381         return trigger_group_objd;
 382
 383 objd_error:
 384         lttng_trigger_group_destroy(trigger_group);
 385 fd_error:
 386         close_ret = close(trigger_notif_fd);
 387         if (close_ret) {
 388                 PERROR("close");
 389         }
 390
 391         return ret;
 392 }
 393
 394 static
 395 long lttng_abi_add_context(int objd,
 396         struct lttng_ust_context *context_param,
 397         union ust_args *uargs,
 398         struct lttng_ctx **ctx, struct lttng_session *session)
 399 {
 400         return lttng_attach_context(context_param, uargs, ctx, session);
 401 }
 402
 403 /**
 404  *      lttng_cmd - lttng control through socket commands
 405  *
 406  *      @objd: the object descriptor
 407  *      @cmd: the command
 408  *      @arg: command arg
 409  *      @uargs: UST arguments (internal)
 410  *      @owner: objd owner
 411  *
 412  *      This descriptor implements lttng commands:
 413  *      LTTNG_UST_SESSION
 414  *              Returns a LTTng trace session object descriptor
 415  *      LTTNG_UST_TRACER_VERSION
 416  *              Returns the LTTng kernel tracer version
 417  *      LTTNG_UST_TRACEPOINT_LIST
 418  *              Returns a file descriptor listing available tracepoints
 419  *      LTTNG_UST_TRACEPOINT_FIELD_LIST
 420  *              Returns a file descriptor listing available tracepoint fields
 421  *      LTTNG_UST_WAIT_QUIESCENT
 422  *              Returns after all previously running probes have completed
 423  *
 424  * The returned session will be deleted when its file descriptor is closed.
 425  */
 426 static
 427 long lttng_cmd(int objd, unsigned int cmd, unsigned long arg,
 428         union ust_args *uargs, void *owner)
 429 {
 430         switch (cmd) {
 431         case LTTNG_UST_SESSION:
 432                 return lttng_abi_create_session(owner);
 433         case LTTNG_UST_TRACER_VERSION:
 434                 return lttng_abi_tracer_version(objd,
 435                                 (struct lttng_ust_tracer_version *) arg);
 436         case LTTNG_UST_TRACEPOINT_LIST:
 437                 return lttng_abi_tracepoint_list(owner);
 438         case LTTNG_UST_TRACEPOINT_FIELD_LIST:
 439                 return lttng_abi_tracepoint_field_list(owner);
 440         case LTTNG_UST_WAIT_QUIESCENT:
 441                 synchronize_trace();
 442                 return 0;
 443         case LTTNG_UST_TRIGGER_GROUP_CREATE:
 444                 return lttng_abi_trigger_send_fd(owner,
 445                         uargs->trigger_handle.trigger_notif_fd);
 446         default:
 447                 return -EINVAL;
 448         }
 449 }
 450
 451 static const struct lttng_ust_objd_ops lttng_ops = {
 452         .cmd = lttng_cmd,
 453 };
 454
 455 int lttng_abi_map_channel(int session_objd,
 456                 struct lttng_ust_channel *ust_chan,
 457                 union ust_args *uargs,
 458                 void *owner)
 459 {
 460         struct lttng_session *session = objd_private(session_objd);
 461         const char *transport_name;
 462         const struct lttng_transport *transport;
 463         const char *chan_name;
 464         int chan_objd;
 465         struct lttng_ust_shm_handle *channel_handle;
 466         struct lttng_channel *lttng_chan;
 467         struct channel *chan;
 468         struct lttng_ust_lib_ring_buffer_config *config;
 469         void *chan_data;
 470         int wakeup_fd;
 471         uint64_t len;
 472         int ret;
 473         enum lttng_ust_chan_type type;
 474
 475         chan_data = uargs->channel.chan_data;
 476         wakeup_fd = uargs->channel.wakeup_fd;
 477         len = ust_chan->len;
 478         type = ust_chan->type;
 479
 480         switch (type) {
 481         case LTTNG_UST_CHAN_PER_CPU:
 482                 break;
 483         default:
 484                 ret = -EINVAL;
 485                 goto invalid;
 486         }
 487
 488         if (session->been_active) {
 489                 ret = -EBUSY;
 490                 goto active;    /* Refuse to add channel to active session */
 491         }
 492
 493         channel_handle = channel_handle_create(chan_data, len, wakeup_fd);
 494         if (!channel_handle) {
 495                 ret = -EINVAL;
 496                 goto handle_error;
 497         }
 498
 499         chan = shmp(channel_handle, channel_handle->chan);
 500         assert(chan);
 501         chan->handle = channel_handle;
 502         config = &chan->backend.config;
 503         lttng_chan = channel_get_private(chan);
 504         if (!lttng_chan) {
 505                 ret = -EINVAL;
 506                 goto alloc_error;
 507         }
 508
 509         /* Lookup transport name */
 510         switch (type) {
 511         case LTTNG_UST_CHAN_PER_CPU:
 512                 if (config->output == RING_BUFFER_MMAP) {
 513                         if (config->mode == RING_BUFFER_OVERWRITE) {
 514                                 if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER) {
 515                                         transport_name = "relay-overwrite-mmap";
 516                                 } else {
 517                                         transport_name = "relay-overwrite-rt-mmap";
 518                                 }
 519                         } else {
 520                                 if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER) {
 521                                         transport_name = "relay-discard-mmap";
 522                                 } else {
 523                                         transport_name = "relay-discard-rt-mmap";
 524                                 }
 525                         }
 526                 } else {
 527                         ret = -EINVAL;
 528                         goto notransport;
 529                 }
 530                 chan_name = "channel";
 531                 break;
 532         default:
 533                 ret = -EINVAL;
 534                 goto notransport;
 535         }
 536         transport = lttng_transport_find(transport_name);
 537         if (!transport) {
 538                 DBG("LTTng transport %s not found\n",
 539                        transport_name);
 540                 ret = -EINVAL;
 541                 goto notransport;
 542         }
 543
 544         chan_objd = objd_alloc(NULL, &lttng_channel_ops, owner, chan_name);
 545         if (chan_objd < 0) {
 546                 ret = chan_objd;
 547                 goto objd_error;
 548         }
 549
 550         /* Initialize our lttng chan */
 551         lttng_chan->chan = chan;
 552         lttng_chan->tstate = 1;
 553         lttng_chan->enabled = 1;
 554         lttng_chan->ctx = NULL;
 555         lttng_chan->session = session;
 556         lttng_chan->ops = &transport->ops;
 557         memcpy(&lttng_chan->chan->backend.config,
 558                 transport->client_config,
 559                 sizeof(lttng_chan->chan->backend.config));
 560         cds_list_add(&lttng_chan->node, &session->chan_head);
 561         lttng_chan->header_type = 0;
 562         lttng_chan->handle = channel_handle;
 563         lttng_chan->type = type;
 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         return ret;
 581
 582         /*
 583          * error path before channel creation (owning chan_data and
 584          * wakeup_fd).
 585          */
 586 handle_error:
 587 active:
 588 invalid:
 589         {
 590                 int close_ret;
 591
 592                 lttng_ust_lock_fd_tracker();
 593                 close_ret = close(wakeup_fd);
 594                 lttng_ust_unlock_fd_tracker();
 595                 if (close_ret) {
 596                         PERROR("close");
 597                 }
 598         }
 599         free(chan_data);
 600         return ret;
 601 }
 602
 603 /**
 604  *      lttng_session_cmd - lttng session object command
 605  *
 606  *      @obj: the object
 607  *      @cmd: the command
 608  *      @arg: command arg
 609  *      @uargs: UST arguments (internal)
 610  *      @owner: objd owner
 611  *
 612  *      This descriptor implements lttng commands:
 613  *      LTTNG_UST_CHANNEL
 614  *              Returns a LTTng channel object descriptor
 615  *      LTTNG_UST_ENABLE
 616  *              Enables tracing for a session (weak enable)
 617  *      LTTNG_UST_DISABLE
 618  *              Disables tracing for a session (strong disable)
 619  *
 620  * The returned channel will be deleted when its file descriptor is closed.
 621  */
 622 static
 623 long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg,
 624         union ust_args *uargs, void *owner)
 625 {
 626         struct lttng_session *session = objd_private(objd);
 627
 628         switch (cmd) {
 629         case LTTNG_UST_CHANNEL:
 630                 return lttng_abi_map_channel(objd,
 631                                 (struct lttng_ust_channel *) arg,
 632                                 uargs, owner);
 633         case LTTNG_UST_SESSION_START:
 634         case LTTNG_UST_ENABLE:
 635                 return lttng_session_enable(session);
 636         case LTTNG_UST_SESSION_STOP:
 637         case LTTNG_UST_DISABLE:
 638                 return lttng_session_disable(session);
 639         case LTTNG_UST_SESSION_STATEDUMP:
 640                 return lttng_session_statedump(session);
 641         case LTTNG_UST_COUNTER:
 642         case LTTNG_UST_COUNTER_GLOBAL:
 643         case LTTNG_UST_COUNTER_CPU:
 644                 /* Not implemented yet. */
 645                 return -EINVAL;
 646         default:
 647                 return -EINVAL;
 648         }
 649 }
 650
 651 /*
 652  * Called when the last file reference is dropped.
 653  *
 654  * Big fat note: channels and events are invariant for the whole session after
 655  * their creation. So this session destruction also destroys all channel and
 656  * event structures specific to this session (they are not destroyed when their
 657  * individual file is released).
 658  */
 659 static
 660 int lttng_release_session(int objd)
 661 {
 662         struct lttng_session *session = objd_private(objd);
 663
 664         if (session) {
 665                 lttng_session_destroy(session);
 666                 return 0;
 667         } else {
 668                 return -EINVAL;
 669         }
 670 }
 671
 672 static const struct lttng_ust_objd_ops lttng_session_ops = {
 673         .release = lttng_release_session,
 674         .cmd = lttng_session_cmd,
 675 };
 676
 677 static int lttng_ust_trigger_enabler_create(int trigger_group_obj, void *owner,
 678                 struct lttng_ust_trigger *trigger_param,
 679                 enum lttng_enabler_format_type type)
 680 {
 681         struct lttng_trigger_group *trigger_group =
 682                 objd_private(trigger_group_obj);
 683         struct lttng_trigger_enabler *trigger_enabler;
 684         int trigger_objd, ret;
 685
 686         trigger_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 687         trigger_objd = objd_alloc(NULL, &lttng_trigger_enabler_ops, owner,
 688                 "trigger enabler");
 689         if (trigger_objd < 0) {
 690                 ret = trigger_objd;
 691                 goto objd_error;
 692         }
 693
 694         trigger_enabler = lttng_trigger_enabler_create(trigger_group, type,
 695                 trigger_param);
 696         if (!trigger_enabler) {
 697                 ret = -ENOMEM;
 698                 goto trigger_error;
 699         }
 700
 701         objd_set_private(trigger_objd, trigger_enabler);
 702         /* The trigger holds a reference on the trigger group. */
 703         objd_ref(trigger_enabler->group->objd);
 704
 705         return trigger_objd;
 706
 707 trigger_error:
 708         {
 709                 int err;
 710
 711                 err = lttng_ust_objd_unref(trigger_objd, 1);
 712                 assert(!err);
 713         }
 714 objd_error:
 715         return ret;
 716 }
 717
 718 static
 719 long lttng_trigger_enabler_cmd(int objd, unsigned int cmd, unsigned long arg,
 720                 union ust_args *uargs, void *owner)
 721 {
 722         struct lttng_trigger_enabler *trigger_enabler = objd_private(objd);
 723         switch (cmd) {
 724         case LTTNG_UST_FILTER:
 725                 return lttng_trigger_enabler_attach_filter_bytecode(
 726                         trigger_enabler,
 727                         (struct lttng_ust_bytecode_node *) arg);
 728         case LTTNG_UST_EXCLUSION:
 729                 return lttng_trigger_enabler_attach_exclusion(trigger_enabler,
 730                         (struct lttng_ust_excluder_node *) arg);
 731         case LTTNG_UST_CAPTURE:
 732                 return lttng_trigger_enabler_attach_capture_bytecode(
 733                         trigger_enabler,
 734                         (struct lttng_ust_bytecode_node *) arg);
 735         case LTTNG_UST_ENABLE:
 736                 return lttng_trigger_enabler_enable(trigger_enabler);
 737         case LTTNG_UST_DISABLE:
 738                 return lttng_trigger_enabler_disable(trigger_enabler);
 739         default:
 740                 return -EINVAL;
 741         }
 742 }
 743
 744 /**
 745  *      lttng_trigger_group_error_counter_cmd - lttng trigger group error counter object command
 746  *
 747  *      @obj: the object
 748  *      @cmd: the command
 749  *      @arg: command arg
 750  *      @uargs: UST arguments (internal)
 751  *      @owner: objd owner
 752  *
 753  *      This descriptor implements lttng commands:
 754  *      LTTNG_UST_COUNTER_GLOBAL
 755  *        Return negative error code on error, 0 on success.
 756  *      LTTNG_UST_COUNTER_CPU
 757  *        Return negative error code on error, 0 on success.
 758  */
 759 static
 760 long lttng_trigger_group_error_counter_cmd(int objd, unsigned int cmd, unsigned long arg,
 761         union ust_args *uargs, void *owner)
 762 {
 763         struct lttng_counter *counter = objd_private(objd);
 764
 765         switch (cmd) {
 766         case LTTNG_UST_COUNTER_GLOBAL:
 767                 return -EINVAL;         /* Unimplemented. */
 768         case LTTNG_UST_COUNTER_CPU:
 769         {
 770                 struct lttng_ust_counter_cpu *counter_cpu =
 771                         (struct lttng_ust_counter_cpu *)arg;
 772                 return lttng_counter_set_cpu_shm(counter->counter,
 773                         counter_cpu->cpu_nr, uargs->counter_shm.shm_fd);
 774         }
 775         default:
 776                 return -EINVAL;
 777         }
 778 }
 779
 780 int lttng_release_trigger_group_error_counter(int objd)
 781 {
 782         struct lttng_counter *counter = objd_private(objd);
 783
 784         if (counter) {
 785                 return lttng_ust_objd_unref(counter->trigger_group->objd, 0);
 786         } else {
 787                 return -EINVAL;
 788         }
 789 }
 790
 791 static const struct lttng_ust_objd_ops lttng_trigger_group_error_counter_ops = {
 792         .release = lttng_release_trigger_group_error_counter,
 793         .cmd = lttng_trigger_group_error_counter_cmd,
 794 };
 795
 796 static
 797 int lttng_ust_trigger_group_create_error_counter(int trigger_group_objd, void *owner,
 798                 struct lttng_ust_counter_conf *error_counter_conf)
 799 {
 800         const char *counter_transport_name;
 801         struct lttng_trigger_group *trigger_group =
 802                 objd_private(trigger_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 (trigger_group->error_counter)
 809                 return -EBUSY;
 810
 811         if (error_counter_conf->arithmetic != LTTNG_UST_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_COUNTER_BITNESS_64BITS:
 819                 counter_transport_name = "counter-per-cpu-64-modular";
 820                 break;
 821         case LTTNG_UST_COUNTER_BITNESS_32BITS:
 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_trigger_group_error_counter_ops, owner,
 829                 "trigger 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         trigger_group->error_counter = counter;
 849         trigger_group->error_counter_len = counter_len;
 850
 851         counter->objd = counter_objd;
 852         counter->trigger_group = trigger_group; /* owner */
 853
 854         objd_set_private(counter_objd, counter);
 855         /* The error counter holds a reference on the trigger group. */
 856         objd_ref(trigger_group->objd);
 857
 858         return counter_objd;
 859
 860 create_error:
 861         {
 862                 int err;
 863
 864                 err = lttng_ust_objd_unref(counter_objd, 1);
 865                 assert(!err);
 866         }
 867 objd_error:
 868         return ret;
 869 }
 870
 871 static
 872 long lttng_trigger_group_cmd(int objd, unsigned int cmd, unsigned long arg,
 873                 union ust_args *uargs, void *owner)
 874 {
 875         switch (cmd) {
 876         case LTTNG_UST_TRIGGER_CREATE:
 877         {
 878                 struct lttng_ust_trigger *trigger_param =
 879                         (struct lttng_ust_trigger *) arg;
 880                 if (strutils_is_star_glob_pattern(trigger_param->name)) {
 881                         /*
 882                          * If the event name is a star globbing pattern,
 883                          * we create the special star globbing enabler.
 884                          */
 885                         return lttng_ust_trigger_enabler_create(objd, owner,
 886                                 trigger_param, LTTNG_ENABLER_FORMAT_STAR_GLOB);
 887                 } else {
 888                         return lttng_ust_trigger_enabler_create(objd, owner,
 889                                 trigger_param, LTTNG_ENABLER_FORMAT_EVENT);
 890                 }
 891         }
 892         case LTTNG_UST_COUNTER:
 893         {
 894                 struct lttng_ust_counter_conf *counter_conf =
 895                         (struct lttng_ust_counter_conf *) uargs->counter.counter_data;
 896                 return lttng_ust_trigger_group_create_error_counter(objd, owner,
 897                                 counter_conf);
 898         }
 899         default:
 900                 return -EINVAL;
 901         }
 902 }
 903
 904 static
 905 int lttng_trigger_enabler_release(int objd)
 906 {
 907         struct lttng_trigger_enabler *trigger_enabler = objd_private(objd);
 908
 909         if (trigger_enabler)
 910                 return lttng_ust_objd_unref(trigger_enabler->group->objd, 0);
 911         return 0;
 912 }
 913
 914 static const struct lttng_ust_objd_ops lttng_trigger_enabler_ops = {
 915         .release = lttng_trigger_enabler_release,
 916         .cmd = lttng_trigger_enabler_cmd,
 917 };
 918
 919 static
 920 int lttng_release_trigger_group(int objd)
 921 {
 922         struct lttng_trigger_group *trigger_group = objd_private(objd);
 923
 924         if (trigger_group) {
 925                 lttng_trigger_group_destroy(trigger_group);
 926                 return 0;
 927         } else {
 928                 return -EINVAL;
 929         }
 930 }
 931
 932 static const struct lttng_ust_objd_ops lttng_trigger_group_ops = {
 933         .release = lttng_release_trigger_group,
 934         .cmd = lttng_trigger_group_cmd,
 935 };
 936
 937 static
 938 long lttng_tracepoint_list_cmd(int objd, unsigned int cmd, unsigned long arg,
 939         union ust_args *uargs, void *owner)
 940 {
 941         struct lttng_ust_tracepoint_list *list = objd_private(objd);
 942         struct lttng_ust_tracepoint_iter *tp =
 943                 (struct lttng_ust_tracepoint_iter *) arg;
 944         struct lttng_ust_tracepoint_iter *iter;
 945
 946         switch (cmd) {
 947         case LTTNG_UST_TRACEPOINT_LIST_GET:
 948         {
 949                 iter = lttng_ust_tracepoint_list_get_iter_next(list);
 950                 if (!iter)
 951                         return -LTTNG_UST_ERR_NOENT;
 952                 memcpy(tp, iter, sizeof(*tp));
 953                 return 0;
 954         }
 955         default:
 956                 return -EINVAL;
 957         }
 958 }
 959
 960 static
 961 int lttng_abi_tracepoint_list(void *owner)
 962 {
 963         int list_objd, ret;
 964         struct lttng_ust_tracepoint_list *list;
 965
 966         list_objd = objd_alloc(NULL, &lttng_tracepoint_list_ops, owner, "tp_list");
 967         if (list_objd < 0) {
 968                 ret = list_objd;
 969                 goto objd_error;
 970         }
 971         list = zmalloc(sizeof(*list));
 972         if (!list) {
 973                 ret = -ENOMEM;
 974                 goto alloc_error;
 975         }
 976         objd_set_private(list_objd, list);
 977
 978         /* populate list by walking on all registered probes. */
 979         ret = lttng_probes_get_event_list(list);
 980         if (ret) {
 981                 goto list_error;
 982         }
 983         return list_objd;
 984
 985 list_error:
 986         free(list);
 987 alloc_error:
 988         {
 989                 int err;
 990
 991                 err = lttng_ust_objd_unref(list_objd, 1);
 992                 assert(!err);
 993         }
 994 objd_error:
 995         return ret;
 996 }
 997
 998 static
 999 int lttng_release_tracepoint_list(int objd)
1000 {
1001         struct lttng_ust_tracepoint_list *list = objd_private(objd);
1002
1003         if (list) {
1004                 lttng_probes_prune_event_list(list);
1005                 free(list);
1006                 return 0;
1007         } else {
1008                 return -EINVAL;
1009         }
1010 }
1011
1012 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops = {
1013         .release = lttng_release_tracepoint_list,
1014         .cmd = lttng_tracepoint_list_cmd,
1015 };
1016
1017 static
1018 long lttng_tracepoint_field_list_cmd(int objd, unsigned int cmd,
1019         unsigned long arg, union ust_args *uargs, void *owner)
1020 {
1021         struct lttng_ust_field_list *list = objd_private(objd);
1022         struct lttng_ust_field_iter *tp = &uargs->field_list.entry;
1023         struct lttng_ust_field_iter *iter;
1024
1025         switch (cmd) {
1026         case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET:
1027         {
1028                 iter = lttng_ust_field_list_get_iter_next(list);
1029                 if (!iter)
1030                         return -LTTNG_UST_ERR_NOENT;
1031                 memcpy(tp, iter, sizeof(*tp));
1032                 return 0;
1033         }
1034         default:
1035                 return -EINVAL;
1036         }
1037 }
1038
1039 static
1040 int lttng_abi_tracepoint_field_list(void *owner)
1041 {
1042         int list_objd, ret;
1043         struct lttng_ust_field_list *list;
1044
1045         list_objd = objd_alloc(NULL, &lttng_tracepoint_field_list_ops, owner,
1046                         "tp_field_list");
1047         if (list_objd < 0) {
1048                 ret = list_objd;
1049                 goto objd_error;
1050         }
1051         list = zmalloc(sizeof(*list));
1052         if (!list) {
1053                 ret = -ENOMEM;
1054                 goto alloc_error;
1055         }
1056         objd_set_private(list_objd, list);
1057
1058         /* populate list by walking on all registered probes. */
1059         ret = lttng_probes_get_field_list(list);
1060         if (ret) {
1061                 goto list_error;
1062         }
1063         return list_objd;
1064
1065 list_error:
1066         free(list);
1067 alloc_error:
1068         {
1069                 int err;
1070
1071                 err = lttng_ust_objd_unref(list_objd, 1);
1072                 assert(!err);
1073         }
1074 objd_error:
1075         return ret;
1076 }
1077
1078 static
1079 int lttng_release_tracepoint_field_list(int objd)
1080 {
1081         struct lttng_ust_field_list *list = objd_private(objd);
1082
1083         if (list) {
1084                 lttng_probes_prune_field_list(list);
1085                 free(list);
1086                 return 0;
1087         } else {
1088                 return -EINVAL;
1089         }
1090 }
1091
1092 static const struct lttng_ust_objd_ops lttng_tracepoint_field_list_ops = {
1093         .release = lttng_release_tracepoint_field_list,
1094         .cmd = lttng_tracepoint_field_list_cmd,
1095 };
1096
1097 static
1098 int lttng_abi_map_stream(int channel_objd, struct lttng_ust_stream *info,
1099                 union ust_args *uargs, void *owner)
1100 {
1101         struct lttng_channel *channel = objd_private(channel_objd);
1102         int ret;
1103
1104         ret = channel_handle_add_stream(channel->handle,
1105                 uargs->stream.shm_fd, uargs->stream.wakeup_fd,
1106                 info->stream_nr, info->len);
1107         if (ret)
1108                 goto error_add_stream;
1109
1110         return 0;
1111
1112 error_add_stream:
1113         return ret;
1114 }
1115
1116 static
1117 int lttng_abi_create_event_enabler(int channel_objd,
1118                            struct lttng_ust_event *event_param,
1119                            void *owner,
1120                            enum lttng_enabler_format_type format_type)
1121 {
1122         struct lttng_channel *channel = objd_private(channel_objd);
1123         struct lttng_event_enabler *enabler;
1124         int event_objd, ret;
1125
1126         event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1127         event_objd = objd_alloc(NULL, &lttng_event_enabler_ops, owner,
1128                 "event enabler");
1129         if (event_objd < 0) {
1130                 ret = event_objd;
1131                 goto objd_error;
1132         }
1133         /*
1134          * We tolerate no failure path after event creation. It will stay
1135          * invariant for the rest of the session.
1136          */
1137         enabler = lttng_event_enabler_create(format_type, event_param, channel);
1138         if (!enabler) {
1139                 ret = -ENOMEM;
1140                 goto event_error;
1141         }
1142         objd_set_private(event_objd, enabler);
1143         /* The event holds a reference on the channel */
1144         objd_ref(channel_objd);
1145         return event_objd;
1146
1147 event_error:
1148         {
1149                 int err;
1150
1151                 err = lttng_ust_objd_unref(event_objd, 1);
1152                 assert(!err);
1153         }
1154 objd_error:
1155         return ret;
1156 }
1157
1158 /**
1159  *      lttng_channel_cmd - lttng control through object descriptors
1160  *
1161  *      @objd: the object descriptor
1162  *      @cmd: the command
1163  *      @arg: command arg
1164  *      @uargs: UST arguments (internal)
1165  *      @owner: objd owner
1166  *
1167  *      This object descriptor implements lttng commands:
1168  *      LTTNG_UST_STREAM
1169  *              Returns an event stream object descriptor or failure.
1170  *              (typically, one event stream records events from one CPU)
1171  *      LTTNG_UST_EVENT
1172  *              Returns an event object descriptor or failure.
1173  *      LTTNG_UST_CONTEXT
1174  *              Prepend a context field to each event in the channel
1175  *      LTTNG_UST_ENABLE
1176  *              Enable recording for events in this channel (weak enable)
1177  *      LTTNG_UST_DISABLE
1178  *              Disable recording for events in this channel (strong disable)
1179  *
1180  * Channel and event file descriptors also hold a reference on the session.
1181  */
1182 static
1183 long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg,
1184         union ust_args *uargs, void *owner)
1185 {
1186         struct lttng_channel *channel = objd_private(objd);
1187
1188         if (cmd != LTTNG_UST_STREAM) {
1189                 /*
1190                  * Check if channel received all streams.
1191                  */
1192                 if (!lttng_is_channel_ready(channel))
1193                         return -EPERM;
1194         }
1195
1196         switch (cmd) {
1197         case LTTNG_UST_STREAM:
1198         {
1199                 struct lttng_ust_stream *stream;
1200
1201                 stream = (struct lttng_ust_stream *) arg;
1202                 /* stream used as output */
1203                 return lttng_abi_map_stream(objd, stream, uargs, owner);
1204         }
1205         case LTTNG_UST_EVENT:
1206         {
1207                 struct lttng_ust_event *event_param =
1208                         (struct lttng_ust_event *) arg;
1209
1210                 if (strutils_is_star_glob_pattern(event_param->name)) {
1211                         /*
1212                          * If the event name is a star globbing pattern,
1213                          * we create the special star globbing enabler.
1214                          */
1215                         return lttng_abi_create_event_enabler(objd, event_param,
1216                                         owner, LTTNG_ENABLER_FORMAT_STAR_GLOB);
1217                 } else {
1218                         return lttng_abi_create_event_enabler(objd, event_param,
1219                                         owner, LTTNG_ENABLER_FORMAT_EVENT);
1220                 }
1221         }
1222         case LTTNG_UST_CONTEXT:
1223                 return lttng_abi_add_context(objd,
1224                                 (struct lttng_ust_context *) arg, uargs,
1225                                 &channel->ctx, channel->session);
1226         case LTTNG_UST_ENABLE:
1227                 return lttng_channel_enable(channel);
1228         case LTTNG_UST_DISABLE:
1229                 return lttng_channel_disable(channel);
1230         case LTTNG_UST_FLUSH_BUFFER:
1231                 return channel->ops->flush_buffer(channel->chan, channel->handle);
1232         default:
1233                 return -EINVAL;
1234         }
1235 }
1236
1237 static
1238 int lttng_channel_release(int objd)
1239 {
1240         struct lttng_channel *channel = objd_private(objd);
1241
1242         if (channel)
1243                 return lttng_ust_objd_unref(channel->session->objd, 0);
1244         return 0;
1245 }
1246
1247 static const struct lttng_ust_objd_ops lttng_channel_ops = {
1248         .release = lttng_channel_release,
1249         .cmd = lttng_channel_cmd,
1250 };
1251
1252 /**
1253  *      lttng_enabler_cmd - lttng control through object descriptors
1254  *
1255  *      @objd: the object descriptor
1256  *      @cmd: the command
1257  *      @arg: command arg
1258  *      @uargs: UST arguments (internal)
1259  *      @owner: objd owner
1260  *
1261  *      This object descriptor implements lttng commands:
1262  *      LTTNG_UST_CONTEXT
1263  *              Prepend a context field to each record of events of this
1264  *              enabler.
1265  *      LTTNG_UST_ENABLE
1266  *              Enable recording for this enabler
1267  *      LTTNG_UST_DISABLE
1268  *              Disable recording for this enabler
1269  *      LTTNG_UST_FILTER
1270  *              Attach a filter to an enabler.
1271  *      LTTNG_UST_EXCLUSION
1272  *              Attach exclusions to an enabler.
1273  */
1274 static
1275 long lttng_event_enabler_cmd(int objd, unsigned int cmd, unsigned long arg,
1276         union ust_args *uargs, void *owner)
1277 {
1278         struct lttng_event_enabler *enabler = objd_private(objd);
1279
1280         switch (cmd) {
1281         case LTTNG_UST_CONTEXT:
1282                 return lttng_event_enabler_attach_context(enabler,
1283                                 (struct lttng_ust_context *) arg);
1284         case LTTNG_UST_ENABLE:
1285                 return lttng_event_enabler_enable(enabler);
1286         case LTTNG_UST_DISABLE:
1287                 return lttng_event_enabler_disable(enabler);
1288         case LTTNG_UST_FILTER:
1289         {
1290                 int ret;
1291
1292                 ret = lttng_event_enabler_attach_filter_bytecode(enabler,
1293                                 (struct lttng_ust_bytecode_node *) arg);
1294                 if (ret)
1295                         return ret;
1296                 return 0;
1297         }
1298         case LTTNG_UST_EXCLUSION:
1299         {
1300                 return lttng_event_enabler_attach_exclusion(enabler,
1301                                 (struct lttng_ust_excluder_node *) arg);
1302         }
1303         default:
1304                 return -EINVAL;
1305         }
1306 }
1307
1308 static
1309 int lttng_event_enabler_release(int objd)
1310 {
1311         struct lttng_event_enabler *event_enabler = objd_private(objd);
1312
1313         if (event_enabler)
1314                 return lttng_ust_objd_unref(event_enabler->chan->objd, 0);
1315
1316         return 0;
1317 }
1318
1319 static const struct lttng_ust_objd_ops lttng_event_enabler_ops = {
1320         .release = lttng_event_enabler_release,
1321         .cmd = lttng_event_enabler_cmd,
1322 };
1323
1324 void lttng_ust_abi_exit(void)
1325 {
1326         lttng_ust_abi_close_in_progress = 1;
1327         ust_lock_nocheck();
1328         objd_table_destroy();
1329         ust_unlock();
1330         lttng_ust_abi_close_in_progress = 0;
1331 }