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 #include <lttng/ust-abi.h>
  41 #include <urcu/compiler.h>
  42 #include <urcu/list.h>
  43 #include <lttng/ust-events.h>
  44 #include <lttng/ust-version.h>
  45 #include <lttng/tracepoint.h>
  46 #include "tracepoint-internal.h"
  47 #include <usterr-signal-safe.h>
  48 #include <helper.h>
  49 #include "ltt-tracer.h"
  50
  51 static int lttng_ust_abi_close_in_progress;
  52
  53 static
  54 int lttng_abi_tracepoint_list(void);
  55
  56 /*
  57  * Object descriptor table. Should be protected from concurrent access
  58  * by the caller.
  59  */
  60
  61 struct lttng_ust_obj {
  62         union {
  63                 struct {
  64                         void *private_data;
  65                         const struct lttng_ust_objd_ops *ops;
  66                         int f_count;
  67                 } s;
  68                 int freelist_next;      /* offset freelist. end is -1. */
  69         } u;
  70 };
  71
  72 struct lttng_ust_objd_table {
  73         struct lttng_ust_obj *array;
  74         unsigned int len, allocated_len;
  75         int freelist_head;              /* offset freelist head. end is -1 */
  76 };
  77
  78 static struct lttng_ust_objd_table objd_table = {
  79         .freelist_head = -1,
  80 };
  81
  82 static
  83 int objd_alloc(void *private_data, const struct lttng_ust_objd_ops *ops)
  84 {
  85         struct lttng_ust_obj *obj;
  86
  87         if (objd_table.freelist_head != -1) {
  88                 obj = &objd_table.array[objd_table.freelist_head];
  89                 objd_table.freelist_head = obj->u.freelist_next;
  90                 goto end;
  91         }
  92
  93         if (objd_table.len >= objd_table.allocated_len) {
  94                 unsigned int new_allocated_len, old_allocated_len;
  95                 struct lttng_ust_obj *new_table, *old_table;
  96
  97                 old_allocated_len = objd_table.allocated_len;
  98                 old_table = objd_table.array;
  99                 if (!old_allocated_len)
 100                         new_allocated_len = 1;
 101                 else
 102                         new_allocated_len = old_allocated_len << 1;
 103                 new_table = zmalloc(sizeof(struct lttng_ust_obj) * new_allocated_len);
 104                 if (!new_table)
 105                         return -ENOMEM;
 106                 memcpy(new_table, old_table,
 107                        sizeof(struct lttng_ust_obj) * old_allocated_len);
 108                 free(old_table);
 109                 objd_table.array = new_table;
 110                 objd_table.allocated_len = new_allocated_len;
 111         }
 112         obj = &objd_table.array[objd_table.len];
 113         objd_table.len++;
 114 end:
 115         obj->u.s.private_data = private_data;
 116         obj->u.s.ops = ops;
 117         obj->u.s.f_count = 2;   /* count == 1 : object is allocated */
 118                                 /* count == 2 : allocated + hold ref */
 119         return obj - objd_table.array;
 120 }
 121
 122 static
 123 struct lttng_ust_obj *_objd_get(int id)
 124 {
 125         if (id >= objd_table.len)
 126                 return NULL;
 127         if (!objd_table.array[id].u.s.f_count)
 128                 return NULL;
 129         return &objd_table.array[id];
 130 }
 131
 132 static
 133 void *objd_private(int id)
 134 {
 135         struct lttng_ust_obj *obj = _objd_get(id);
 136         assert(obj);
 137         return obj->u.s.private_data;
 138 }
 139
 140 static
 141 void objd_set_private(int id, void *private_data)
 142 {
 143         struct lttng_ust_obj *obj = _objd_get(id);
 144         assert(obj);
 145         obj->u.s.private_data = private_data;
 146 }
 147
 148 const struct lttng_ust_objd_ops *objd_ops(int id)
 149 {
 150         struct lttng_ust_obj *obj = _objd_get(id);
 151
 152         if (!obj)
 153                 return NULL;
 154         return obj->u.s.ops;
 155 }
 156
 157 static
 158 void objd_free(int id)
 159 {
 160         struct lttng_ust_obj *obj = _objd_get(id);
 161
 162         assert(obj);
 163         obj->u.freelist_next = objd_table.freelist_head;
 164         objd_table.freelist_head = obj - objd_table.array;
 165         assert(obj->u.s.f_count == 1);
 166         obj->u.s.f_count = 0;   /* deallocated */
 167 }
 168
 169 static
 170 void objd_ref(int id)
 171 {
 172         struct lttng_ust_obj *obj = _objd_get(id);
 173         obj->u.s.f_count++;
 174 }
 175
 176 int lttng_ust_objd_unref(int id)
 177 {
 178         struct lttng_ust_obj *obj = _objd_get(id);
 179
 180         if (!obj)
 181                 return -EINVAL;
 182         if (obj->u.s.f_count == 1) {
 183                 ERR("Reference counting error\n");
 184                 return -EINVAL;
 185         }
 186         if ((--obj->u.s.f_count) == 1) {
 187                 const struct lttng_ust_objd_ops *ops = objd_ops(id);
 188
 189                 if (ops->release)
 190                         ops->release(id);
 191                 objd_free(id);
 192         }
 193         return 0;
 194 }
 195
 196 static
 197 void objd_table_destroy(void)
 198 {
 199         int i;
 200
 201         for (i = 0; i < objd_table.allocated_len; i++)
 202                 (void) lttng_ust_objd_unref(i);
 203         free(objd_table.array);
 204         objd_table.array = NULL;
 205         objd_table.len = 0;
 206         objd_table.allocated_len = 0;
 207         objd_table.freelist_head = -1;
 208 }
 209
 210 /*
 211  * This is LTTng's own personal way to create an ABI for sessiond.
 212  * We send commands over a socket.
 213  */
 214
 215 static const struct lttng_ust_objd_ops lttng_ops;
 216 static const struct lttng_ust_objd_ops lttng_session_ops;
 217 static const struct lttng_ust_objd_ops lttng_channel_ops;
 218 static const struct lttng_ust_objd_ops lttng_metadata_ops;
 219 static const struct lttng_ust_objd_ops lttng_event_ops;
 220 static const struct lttng_ust_objd_ops lttng_wildcard_ops;
 221 static const struct lttng_ust_objd_ops lib_ring_buffer_objd_ops;
 222 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops;
 223
 224 enum channel_type {
 225         PER_CPU_CHANNEL,
 226         METADATA_CHANNEL,
 227 };
 228
 229 int lttng_abi_create_root_handle(void)
 230 {
 231         int root_handle;
 232
 233         root_handle = objd_alloc(NULL, &lttng_ops);
 234         return root_handle;
 235 }
 236
 237 static
 238 int lttng_abi_create_session(void)
 239 {
 240         struct ltt_session *session;
 241         int session_objd, ret;
 242
 243         session = ltt_session_create();
 244         if (!session)
 245                 return -ENOMEM;
 246         session_objd = objd_alloc(session, &lttng_session_ops);
 247         if (session_objd < 0) {
 248                 ret = session_objd;
 249                 goto objd_error;
 250         }
 251         session->objd = session_objd;
 252         return session_objd;
 253
 254 objd_error:
 255         ltt_session_destroy(session);
 256         return ret;
 257 }
 258
 259 static
 260 long lttng_abi_tracer_version(int objd,
 261         struct lttng_ust_tracer_version *v)
 262 {
 263         v->major = LTTNG_UST_MAJOR_VERSION;
 264         v->minor = LTTNG_UST_MINOR_VERSION;
 265         v->patchlevel = LTTNG_UST_PATCHLEVEL_VERSION;
 266         return 0;
 267 }
 268
 269 static
 270 long lttng_abi_add_context(int objd,
 271         struct lttng_ust_context *context_param,
 272         struct lttng_ctx **ctx, struct ltt_session *session)
 273 {
 274         if (session->been_active)
 275                 return -EPERM;
 276
 277         switch (context_param->ctx) {
 278         case LTTNG_UST_CONTEXT_PTHREAD_ID:
 279                 return lttng_add_pthread_id_to_ctx(ctx);
 280         case LTTNG_UST_CONTEXT_VTID:
 281                 return lttng_add_vtid_to_ctx(ctx);
 282         case LTTNG_UST_CONTEXT_VPID:
 283                 return lttng_add_vpid_to_ctx(ctx);
 284         case LTTNG_UST_CONTEXT_PROCNAME:
 285                 return lttng_add_procname_to_ctx(ctx);
 286         default:
 287                 return -EINVAL;
 288         }
 289 }
 290
 291 /**
 292  *      lttng_cmd - lttng control through socket commands
 293  *
 294  *      @objd: the object descriptor
 295  *      @cmd: the command
 296  *      @arg: command arg
 297  *      @uargs: UST arguments (internal)
 298  *
 299  *      This descriptor implements lttng commands:
 300  *      LTTNG_UST_SESSION
 301  *              Returns a LTTng trace session object descriptor
 302  *      LTTNG_UST_TRACER_VERSION
 303  *              Returns the LTTng kernel tracer version
 304  *      LTTNG_UST_TRACEPOINT_LIST
 305  *              Returns a file descriptor listing available tracepoints
 306  *      LTTNG_UST_WAIT_QUIESCENT
 307  *              Returns after all previously running probes have completed
 308  *
 309  * The returned session will be deleted when its file descriptor is closed.
 310  */
 311 static
 312 long lttng_cmd(int objd, unsigned int cmd, unsigned long arg,
 313         union ust_args *uargs)
 314 {
 315         switch (cmd) {
 316         case LTTNG_UST_SESSION:
 317                 return lttng_abi_create_session();
 318         case LTTNG_UST_TRACER_VERSION:
 319                 return lttng_abi_tracer_version(objd,
 320                                 (struct lttng_ust_tracer_version *) arg);
 321         case LTTNG_UST_TRACEPOINT_LIST:
 322                 return lttng_abi_tracepoint_list();
 323         case LTTNG_UST_WAIT_QUIESCENT:
 324                 synchronize_trace();
 325                 return 0;
 326         default:
 327                 return -EINVAL;
 328         }
 329 }
 330
 331 static const struct lttng_ust_objd_ops lttng_ops = {
 332         .cmd = lttng_cmd,
 333 };
 334
 335 /*
 336  * We tolerate no failure in this function (if one happens, we print a dmesg
 337  * error, but cannot return any error, because the channel information is
 338  * invariant.
 339  */
 340 static
 341 void lttng_metadata_create_events(int channel_objd)
 342 {
 343         struct ltt_channel *channel = objd_private(channel_objd);
 344         static struct lttng_ust_event metadata_params = {
 345                 .instrumentation = LTTNG_UST_TRACEPOINT,
 346                 .name = "lttng_ust:metadata",
 347                 .loglevel_type = LTTNG_UST_LOGLEVEL_ALL,
 348                 .loglevel = TRACE_DEFAULT,
 349         };
 350         struct ltt_event *event;
 351         int ret;
 352
 353         /*
 354          * We tolerate no failure path after event creation. It will stay
 355          * invariant for the rest of the session.
 356          */
 357         ret = ltt_event_create(channel, &metadata_params, NULL, &event);
 358         if (ret < 0) {
 359                 goto create_error;
 360         }
 361         return;
 362
 363 create_error:
 364         WARN_ON(1);
 365         return;         /* not allowed to return error */
 366 }
 367
 368 int lttng_abi_create_channel(int session_objd,
 369                              struct lttng_ust_channel *chan_param,
 370                              enum channel_type channel_type,
 371                              union ust_args *uargs)
 372 {
 373         struct ltt_session *session = objd_private(session_objd);
 374         const struct lttng_ust_objd_ops *ops;
 375         const char *transport_name;
 376         struct ltt_channel *chan;
 377         int chan_objd;
 378         int ret = 0;
 379         struct ltt_channel chan_priv_init;
 380
 381         switch (channel_type) {
 382         case PER_CPU_CHANNEL:
 383                 if (chan_param->output == LTTNG_UST_MMAP) {
 384                         transport_name = chan_param->overwrite ?
 385                                 "relay-overwrite-mmap" : "relay-discard-mmap";
 386                 } else {
 387                         return -EINVAL;
 388                 }
 389                 ops = &lttng_channel_ops;
 390                 break;
 391         case METADATA_CHANNEL:
 392                 if (chan_param->output == LTTNG_UST_MMAP)
 393                         transport_name = "relay-metadata-mmap";
 394                 else
 395                         return -EINVAL;
 396                 ops = &lttng_metadata_ops;
 397                 break;
 398         default:
 399                 transport_name = "<unknown>";
 400                 return -EINVAL;
 401         }
 402         chan_objd = objd_alloc(NULL, ops);
 403         if (chan_objd < 0) {
 404                 ret = chan_objd;
 405                 goto objd_error;
 406         }
 407         memset(&chan_priv_init, 0, sizeof(chan_priv_init));
 408         /* Copy of session UUID for consumer (availability through shm) */
 409         memcpy(chan_priv_init.uuid, session->uuid, sizeof(session->uuid));
 410
 411         /*
 412          * We tolerate no failure path after channel creation. It will stay
 413          * invariant for the rest of the session.
 414          */
 415         chan = ltt_channel_create(session, transport_name, NULL,
 416                                   chan_param->subbuf_size,
 417                                   chan_param->num_subbuf,
 418                                   chan_param->switch_timer_interval,
 419                                   chan_param->read_timer_interval,
 420                                   &uargs->channel.shm_fd,
 421                                   &uargs->channel.wait_fd,
 422                                   &uargs->channel.memory_map_size,
 423                                   &chan_priv_init);
 424         if (!chan) {
 425                 ret = -EINVAL;
 426                 goto chan_error;
 427         }
 428         objd_set_private(chan_objd, chan);
 429         chan->objd = chan_objd;
 430         if (channel_type == METADATA_CHANNEL) {
 431                 session->metadata = chan;
 432                 lttng_metadata_create_events(chan_objd);
 433         }
 434         /* The channel created holds a reference on the session */
 435         objd_ref(session_objd);
 436
 437         return chan_objd;
 438
 439 chan_error:
 440         {
 441                 int err;
 442
 443                 err = lttng_ust_objd_unref(chan_objd);
 444                 assert(!err);
 445         }
 446 objd_error:
 447         return ret;
 448 }
 449
 450 /**
 451  *      lttng_session_cmd - lttng session object command
 452  *
 453  *      @obj: the object
 454  *      @cmd: the command
 455  *      @arg: command arg
 456  *      @uargs: UST arguments (internal)
 457  *
 458  *      This descriptor implements lttng commands:
 459  *      LTTNG_UST_CHANNEL
 460  *              Returns a LTTng channel object descriptor
 461  *      LTTNG_UST_ENABLE
 462  *              Enables tracing for a session (weak enable)
 463  *      LTTNG_UST_DISABLE
 464  *              Disables tracing for a session (strong disable)
 465  *      LTTNG_UST_METADATA
 466  *              Returns a LTTng metadata object descriptor
 467  *
 468  * The returned channel will be deleted when its file descriptor is closed.
 469  */
 470 static
 471 long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg,
 472         union ust_args *uargs)
 473 {
 474         struct ltt_session *session = objd_private(objd);
 475
 476         switch (cmd) {
 477         case LTTNG_UST_CHANNEL:
 478                 return lttng_abi_create_channel(objd,
 479                                 (struct lttng_ust_channel *) arg,
 480                                 PER_CPU_CHANNEL, uargs);
 481         case LTTNG_UST_SESSION_START:
 482         case LTTNG_UST_ENABLE:
 483                 return ltt_session_enable(session);
 484         case LTTNG_UST_SESSION_STOP:
 485         case LTTNG_UST_DISABLE:
 486                 return ltt_session_disable(session);
 487         case LTTNG_UST_METADATA:
 488                 return lttng_abi_create_channel(objd,
 489                                 (struct lttng_ust_channel *) arg,
 490                                 METADATA_CHANNEL, uargs);
 491         default:
 492                 return -EINVAL;
 493         }
 494 }
 495
 496 /*
 497  * Called when the last file reference is dropped.
 498  *
 499  * Big fat note: channels and events are invariant for the whole session after
 500  * their creation. So this session destruction also destroys all channel and
 501  * event structures specific to this session (they are not destroyed when their
 502  * individual file is released).
 503  */
 504 static
 505 int lttng_release_session(int objd)
 506 {
 507         struct ltt_session *session = objd_private(objd);
 508
 509         if (session) {
 510                 ltt_session_destroy(session);
 511                 return 0;
 512         } else {
 513                 return -EINVAL;
 514         }
 515 }
 516
 517 static const struct lttng_ust_objd_ops lttng_session_ops = {
 518         .release = lttng_release_session,
 519         .cmd = lttng_session_cmd,
 520 };
 521
 522 static
 523 long lttng_tracepoint_list_cmd(int objd, unsigned int cmd, unsigned long arg,
 524         union ust_args *uargs)
 525 {
 526         struct lttng_ust_tracepoint_list *list = objd_private(objd);
 527         struct lttng_ust_tracepoint_iter *tp =
 528                 (struct lttng_ust_tracepoint_iter *) arg;
 529         struct lttng_ust_tracepoint_iter *iter;
 530
 531         switch (cmd) {
 532         case LTTNG_UST_TRACEPOINT_LIST_GET:
 533         {
 534         retry:
 535                 iter = lttng_ust_tracepoint_list_get_iter_next(list);
 536                 if (!iter)
 537                         return -ENOENT;
 538                 if (!strcmp(iter->name, "lttng_ust:metadata"))
 539                         goto retry;
 540                 memcpy(tp, iter, sizeof(*tp));
 541                 return 0;
 542         }
 543         default:
 544                 return -EINVAL;
 545         }
 546 }
 547
 548 static
 549 int lttng_abi_tracepoint_list(void)
 550 {
 551         int list_objd, ret;
 552         struct lttng_ust_tracepoint_list *list;
 553
 554         list_objd = objd_alloc(NULL, &lttng_tracepoint_list_ops);
 555         if (list_objd < 0) {
 556                 ret = list_objd;
 557                 goto objd_error;
 558         }
 559         list = zmalloc(sizeof(*list));
 560         if (!list) {
 561                 ret = -ENOMEM;
 562                 goto alloc_error;
 563         }
 564         objd_set_private(list_objd, list);
 565
 566         /* populate list by walking on all registered probes. */
 567         ret = ltt_probes_get_event_list(list);
 568         if (ret) {
 569                 goto list_error;
 570         }
 571         return list_objd;
 572
 573 list_error:
 574         free(list);
 575 alloc_error:
 576         {
 577                 int err;
 578
 579                 err = lttng_ust_objd_unref(list_objd);
 580                 assert(!err);
 581         }
 582 objd_error:
 583         return ret;
 584 }
 585
 586 static
 587 int lttng_release_tracepoint_list(int objd)
 588 {
 589         struct lttng_ust_tracepoint_list *list = objd_private(objd);
 590
 591         if (list) {
 592                 ltt_probes_prune_event_list(list);
 593                 free(list);
 594                 return 0;
 595         } else {
 596                 return -EINVAL;
 597         }
 598 }
 599
 600 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops = {
 601         .release = lttng_release_tracepoint_list,
 602         .cmd = lttng_tracepoint_list_cmd,
 603 };
 604
 605 struct stream_priv_data {
 606         struct lttng_ust_lib_ring_buffer *buf;
 607         struct ltt_channel *ltt_chan;
 608 };
 609
 610 static
 611 int lttng_abi_open_stream(int channel_objd, struct lttng_ust_stream *info,
 612                 union ust_args *uargs)
 613 {
 614         struct ltt_channel *channel = objd_private(channel_objd);
 615         struct lttng_ust_lib_ring_buffer *buf;
 616         struct stream_priv_data *priv;
 617         int stream_objd, ret;
 618
 619         buf = channel->ops->buffer_read_open(channel->chan, channel->handle,
 620                         &uargs->stream.shm_fd,
 621                         &uargs->stream.wait_fd,
 622                         &uargs->stream.memory_map_size);
 623         if (!buf)
 624                 return -ENOENT;
 625
 626         priv = zmalloc(sizeof(*priv));
 627         if (!priv) {
 628                 ret = -ENOMEM;
 629                 goto alloc_error;
 630         }
 631         priv->buf = buf;
 632         priv->ltt_chan = channel;
 633         stream_objd = objd_alloc(priv, &lib_ring_buffer_objd_ops);
 634         if (stream_objd < 0) {
 635                 ret = stream_objd;
 636                 goto objd_error;
 637         }
 638         /* Hold a reference on the channel object descriptor */
 639         objd_ref(channel_objd);
 640         return stream_objd;
 641
 642 objd_error:
 643         free(priv);
 644 alloc_error:
 645         channel->ops->buffer_read_close(buf, channel->handle);
 646         return ret;
 647 }
 648
 649 static
 650 int lttng_abi_create_event(int channel_objd,
 651                            struct lttng_ust_event *event_param)
 652 {
 653         struct ltt_channel *channel = objd_private(channel_objd);
 654         struct ltt_event *event;
 655         int event_objd, ret;
 656
 657         event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 658         event_objd = objd_alloc(NULL, &lttng_event_ops);
 659         if (event_objd < 0) {
 660                 ret = event_objd;
 661                 goto objd_error;
 662         }
 663         /*
 664          * We tolerate no failure path after event creation. It will stay
 665          * invariant for the rest of the session.
 666          */
 667         ret = ltt_event_create(channel, event_param, NULL, &event);
 668         if (ret < 0) {
 669                 goto event_error;
 670         }
 671         objd_set_private(event_objd, event);
 672         /* The event holds a reference on the channel */
 673         objd_ref(channel_objd);
 674         return event_objd;
 675
 676 event_error:
 677         {
 678                 int err;
 679
 680                 err = lttng_ust_objd_unref(event_objd);
 681                 assert(!err);
 682         }
 683 objd_error:
 684         return ret;
 685 }
 686
 687 static
 688 int lttng_abi_create_wildcard(int channel_objd,
 689                               struct lttng_ust_event *event_param)
 690 {
 691         struct ltt_channel *channel = objd_private(channel_objd);
 692         struct session_wildcard *wildcard;
 693         int wildcard_objd, ret;
 694
 695         event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 696         wildcard_objd = objd_alloc(NULL, &lttng_wildcard_ops);
 697         if (wildcard_objd < 0) {
 698                 ret = wildcard_objd;
 699                 goto objd_error;
 700         }
 701         /*
 702          * We tolerate no failure path after wildcard creation. It will
 703          * stay invariant for the rest of the session.
 704          */
 705         ret = ltt_wildcard_create(channel, event_param, &wildcard);
 706         if (ret < 0) {
 707                 goto wildcard_error;
 708         }
 709         objd_set_private(wildcard_objd, wildcard);
 710         /* The wildcard holds a reference on the channel */
 711         objd_ref(channel_objd);
 712         return wildcard_objd;
 713
 714 wildcard_error:
 715         {
 716                 int err;
 717
 718                 err = lttng_ust_objd_unref(wildcard_objd);
 719                 assert(!err);
 720         }
 721 objd_error:
 722         return ret;
 723 }
 724
 725 /**
 726  *      lttng_channel_cmd - lttng control through object descriptors
 727  *
 728  *      @objd: the object descriptor
 729  *      @cmd: the command
 730  *      @arg: command arg
 731  *      @uargs: UST arguments (internal)
 732  *
 733  *      This object descriptor implements lttng commands:
 734  *      LTTNG_UST_STREAM
 735  *              Returns an event stream object descriptor or failure.
 736  *              (typically, one event stream records events from one CPU)
 737  *      LTTNG_UST_EVENT
 738  *              Returns an event object descriptor or failure.
 739  *      LTTNG_UST_CONTEXT
 740  *              Prepend a context field to each event in the channel
 741  *      LTTNG_UST_ENABLE
 742  *              Enable recording for events in this channel (weak enable)
 743  *      LTTNG_UST_DISABLE
 744  *              Disable recording for events in this channel (strong disable)
 745  *
 746  * Channel and event file descriptors also hold a reference on the session.
 747  */
 748 static
 749 long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg,
 750         union ust_args *uargs)
 751 {
 752         struct ltt_channel *channel = objd_private(objd);
 753
 754         switch (cmd) {
 755         case LTTNG_UST_STREAM:
 756         {
 757                 struct lttng_ust_stream *stream;
 758
 759                 stream = (struct lttng_ust_stream *) arg;
 760                 /* stream used as output */
 761                 return lttng_abi_open_stream(objd, stream, uargs);
 762         }
 763         case LTTNG_UST_EVENT:
 764         {
 765                 struct lttng_ust_event *event_param =
 766                         (struct lttng_ust_event *) arg;
 767                 if (event_param->name[strlen(event_param->name) - 1] == '*') {
 768                         /* If ends with wildcard, create wildcard. */
 769                         return lttng_abi_create_wildcard(objd, event_param);
 770                 } else {
 771                         return lttng_abi_create_event(objd, event_param);
 772                 }
 773         }
 774         case LTTNG_UST_CONTEXT:
 775                 return lttng_abi_add_context(objd,
 776                                 (struct lttng_ust_context *) arg,
 777                                 &channel->ctx, channel->session);
 778         case LTTNG_UST_ENABLE:
 779                 return ltt_channel_enable(channel);
 780         case LTTNG_UST_DISABLE:
 781                 return ltt_channel_disable(channel);
 782         case LTTNG_UST_FLUSH_BUFFER:
 783                 return channel->ops->flush_buffer(channel->chan, channel->handle);
 784         default:
 785                 return -EINVAL;
 786         }
 787 }
 788
 789 /**
 790  *      lttng_metadata_cmd - lttng control through object descriptors
 791  *
 792  *      @objd: the object descriptor
 793  *      @cmd: the command
 794  *      @arg: command arg
 795  *      @uargs: UST arguments (internal)
 796  *
 797  *      This object descriptor implements lttng commands:
 798  *      LTTNG_UST_STREAM
 799  *              Returns an event stream file descriptor or failure.
 800  *
 801  * Channel and event file descriptors also hold a reference on the session.
 802  */
 803 static
 804 long lttng_metadata_cmd(int objd, unsigned int cmd, unsigned long arg,
 805         union ust_args *uargs)
 806 {
 807         struct ltt_channel *channel = objd_private(objd);
 808
 809         switch (cmd) {
 810         case LTTNG_UST_STREAM:
 811         {
 812                 struct lttng_ust_stream *stream;
 813
 814                 stream = (struct lttng_ust_stream *) arg;
 815                 /* stream used as output */
 816                 return lttng_abi_open_stream(objd, stream, uargs);
 817         }
 818         case LTTNG_UST_FLUSH_BUFFER:
 819                 return channel->ops->flush_buffer(channel->chan, channel->handle);
 820         default:
 821                 return -EINVAL;
 822         }
 823 }
 824
 825 #if 0
 826 /**
 827  *      lttng_channel_poll - lttng stream addition/removal monitoring
 828  *
 829  *      @file: the file
 830  *      @wait: poll table
 831  */
 832 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
 833 {
 834         struct ltt_channel *channel = file->private_data;
 835         unsigned int mask = 0;
 836
 837         if (file->f_mode & FMODE_READ) {
 838                 poll_wait_set_exclusive(wait);
 839                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
 840                           wait);
 841
 842                 if (channel->ops->is_disabled(channel->chan))
 843                         return POLLERR;
 844                 if (channel->ops->is_finalized(channel->chan))
 845                         return POLLHUP;
 846                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
 847                         return POLLIN | POLLRDNORM;
 848                 return 0;
 849         }
 850         return mask;
 851
 852 }
 853 #endif //0
 854
 855 static
 856 int lttng_channel_release(int objd)
 857 {
 858         struct ltt_channel *channel = objd_private(objd);
 859
 860         if (channel)
 861                 return lttng_ust_objd_unref(channel->session->objd);
 862         return 0;
 863 }
 864
 865 static const struct lttng_ust_objd_ops lttng_channel_ops = {
 866         .release = lttng_channel_release,
 867         //.poll = lttng_channel_poll,
 868         .cmd = lttng_channel_cmd,
 869 };
 870
 871 static const struct lttng_ust_objd_ops lttng_metadata_ops = {
 872         .release = lttng_channel_release,
 873         .cmd = lttng_metadata_cmd,
 874 };
 875
 876 /**
 877  *      lttng_rb_cmd - lttng ring buffer control through object descriptors
 878  *
 879  *      @objd: the object descriptor
 880  *      @cmd: the command
 881  *      @arg: command arg
 882  *      @uargs: UST arguments (internal)
 883  *
 884  *      This object descriptor implements lttng commands:
 885  *              (None for now. Access is done directly though shm.)
 886  */
 887 static
 888 long lttng_rb_cmd(int objd, unsigned int cmd, unsigned long arg,
 889         union ust_args *uargs)
 890 {
 891         switch (cmd) {
 892         default:
 893                 return -EINVAL;
 894         }
 895 }
 896
 897 static
 898 int lttng_rb_release(int objd)
 899 {
 900         struct stream_priv_data *priv = objd_private(objd);
 901         struct lttng_ust_lib_ring_buffer *buf;
 902         struct ltt_channel *channel;
 903
 904         if (priv) {
 905                 buf = priv->buf;
 906                 channel = priv->ltt_chan;
 907                 free(priv);
 908                 /*
 909                  * If we are at ABI exit, we don't want to close the
 910                  * buffer opened for read: it is being shared between
 911                  * the parent and child (right after fork), and we don't
 912                  * want the child to close it for the parent. For a real
 913                  * exit, we don't care about marking it as closed, as
 914                  * the consumer daemon (if there is one) will do fine
 915                  * even if we don't mark it as "closed" for reading on
 916                  * our side.
 917                  * We only mark it as closed if it is being explicitely
 918                  * released by the session daemon with an explicit
 919                  * release command.
 920                  */
 921                 if (!lttng_ust_abi_close_in_progress)
 922                         channel->ops->buffer_read_close(buf, channel->handle);
 923
 924                 return lttng_ust_objd_unref(channel->objd);
 925         }
 926         return 0;
 927 }
 928
 929 static const struct lttng_ust_objd_ops lib_ring_buffer_objd_ops = {
 930         .release = lttng_rb_release,
 931         .cmd = lttng_rb_cmd,
 932 };
 933
 934 /**
 935  *      lttng_event_cmd - lttng control through object descriptors
 936  *
 937  *      @objd: the object descriptor
 938  *      @cmd: the command
 939  *      @arg: command arg
 940  *      @uargs: UST arguments (internal)
 941  *
 942  *      This object descriptor implements lttng commands:
 943  *      LTTNG_UST_CONTEXT
 944  *              Prepend a context field to each record of this event
 945  *      LTTNG_UST_ENABLE
 946  *              Enable recording for this event (weak enable)
 947  *      LTTNG_UST_DISABLE
 948  *              Disable recording for this event (strong disable)
 949  */
 950 static
 951 long lttng_event_cmd(int objd, unsigned int cmd, unsigned long arg,
 952         union ust_args *uargs)
 953 {
 954         struct ltt_event *event = objd_private(objd);
 955
 956         switch (cmd) {
 957         case LTTNG_UST_CONTEXT:
 958                 return lttng_abi_add_context(objd,
 959                                 (struct lttng_ust_context *) arg,
 960                                 &event->ctx, event->chan->session);
 961         case LTTNG_UST_ENABLE:
 962                 return ltt_event_enable(event);
 963         case LTTNG_UST_DISABLE:
 964                 return ltt_event_disable(event);
 965         default:
 966                 return -EINVAL;
 967         }
 968 }
 969
 970 static
 971 int lttng_event_release(int objd)
 972 {
 973         struct ltt_event *event = objd_private(objd);
 974
 975         if (event)
 976                 return lttng_ust_objd_unref(event->chan->objd);
 977         return 0;
 978 }
 979
 980 /* TODO: filter control ioctl */
 981 static const struct lttng_ust_objd_ops lttng_event_ops = {
 982         .release = lttng_event_release,
 983         .cmd = lttng_event_cmd,
 984 };
 985
 986 /**
 987  *      lttng_wildcard_cmd - lttng control through object descriptors
 988  *
 989  *      @objd: the object descriptor
 990  *      @cmd: the command
 991  *      @arg: command arg
 992  *      @uargs: UST arguments (internal)
 993  *
 994  *      This object descriptor implements lttng commands:
 995  *      LTTNG_UST_CONTEXT
 996  *              Prepend a context field to each record of events of this
 997  *              wildcard.
 998  *      LTTNG_UST_ENABLE
 999  *              Enable recording for these wildcard events (weak enable)
1000  *      LTTNG_UST_DISABLE
1001  *              Disable recording for these wildcard events (strong disable)
1002  */
1003 static
1004 long lttng_wildcard_cmd(int objd, unsigned int cmd, unsigned long arg,
1005         union ust_args *uargs)
1006 {
1007         struct session_wildcard *wildcard = objd_private(objd);
1008
1009         switch (cmd) {
1010         case LTTNG_UST_CONTEXT:
1011                 return -ENOSYS; /* not implemented yet */
1012 #if 0
1013                 return lttng_abi_add_context(objd,
1014                                 (struct lttng_ust_context *) arg,
1015                                 &wildcard->ctx, wildcard->chan->session);
1016 #endif
1017         case LTTNG_UST_ENABLE:
1018                 return ltt_wildcard_enable(wildcard);
1019         case LTTNG_UST_DISABLE:
1020                 return ltt_wildcard_disable(wildcard);
1021         default:
1022                 return -EINVAL;
1023         }
1024 }
1025
1026 static
1027 int lttng_wildcard_release(int objd)
1028 {
1029         struct session_wildcard *wildcard = objd_private(objd);
1030
1031         if (wildcard)
1032                 return lttng_ust_objd_unref(wildcard->chan->objd);
1033         return 0;
1034 }
1035
1036 /* TODO: filter control ioctl */
1037 static const struct lttng_ust_objd_ops lttng_wildcard_ops = {
1038         .release = lttng_wildcard_release,
1039         .cmd = lttng_wildcard_cmd,
1040 };
1041
1042 void lttng_ust_abi_exit(void)
1043 {
1044         lttng_ust_abi_close_in_progress = 1;
1045         objd_table_destroy();
1046         lttng_ust_abi_close_in_progress = 0;
1047 }