liblttng-ust/ltt-events.c

   1 /*
   2  * ltt-events.c
   3  *
   4  * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * Holds LTTng per-session event registry.
   7  *
   8  * Dual LGPL v2.1/GPL v2 license.
   9  */
  10
  11 #define _GNU_SOURCE
  12 #include <stdio.h>
  13 #include <endian.h>
  14 #include <urcu/list.h>
  15 #include <urcu/hlist.h>
  16 #include <pthread.h>
  17 #include <uuid/uuid.h>
  18 #include <errno.h>
  19 #include <sys/shm.h>
  20 #include <sys/ipc.h>
  21 #include <stdint.h>
  22 #include <stddef.h>
  23 #include <inttypes.h>
  24 #include <time.h>
  25 #include "clock.h"
  26
  27 #include <urcu-bp.h>
  28 #include <urcu/compiler.h>
  29 #include <urcu/uatomic.h>
  30 #include <urcu/arch.h>
  31
  32 #include <lttng/tracepoint.h>
  33 #include <lttng/ust-events.h>
  34
  35 #include <usterr-signal-safe.h>
  36 #include <helper.h>
  37 #include "error.h"
  38
  39 #include "tracepoint-internal.h"
  40 #include "ltt-tracer.h"
  41 #include "ltt-tracer-core.h"
  42 #include "wait.h"
  43 #include "../libringbuffer/shm.h"
  44 #include "jhash.h"
  45
  46 /*
  47  * The sessions mutex is the centralized mutex across UST tracing
  48  * control and probe registration. All operations within this file are
  49  * called by the communication thread, under ust_lock protection.
  50  */
  51 static pthread_mutex_t sessions_mutex = PTHREAD_MUTEX_INITIALIZER;
  52
  53 void ust_lock(void)
  54 {
  55         pthread_mutex_lock(&sessions_mutex);
  56 }
  57
  58 void ust_unlock(void)
  59 {
  60         pthread_mutex_unlock(&sessions_mutex);
  61 }
  62
  63 static CDS_LIST_HEAD(sessions);
  64
  65 /*
  66  * Wildcard list, containing the active wildcards.
  67  * Protected by ust lock.
  68  */
  69 static CDS_LIST_HEAD(wildcard_list);
  70
  71 /*
  72  * Pending probes hash table, containing the registered ltt events for
  73  * which tracepoint probes are still missing. Protected by the sessions
  74  * mutex.
  75  */
  76 #define PENDING_PROBE_HASH_BITS         6
  77 #define PENDING_PROBE_HASH_SIZE         (1 << PENDING_PROBE_HASH_BITS)
  78 static struct cds_hlist_head pending_probe_table[PENDING_PROBE_HASH_SIZE];
  79
  80 struct ust_pending_probe {
  81         struct ltt_event *event;
  82         struct cds_hlist_node node;
  83         enum lttng_ust_loglevel_type loglevel_type;
  84         int loglevel;
  85         char name[];
  86 };
  87
  88 static void _ltt_event_destroy(struct ltt_event *event);
  89 static void _ltt_wildcard_destroy(struct session_wildcard *sw);
  90 static void _ltt_channel_destroy(struct ltt_channel *chan);
  91 static int _ltt_event_unregister(struct ltt_event *event);
  92 static
  93 int _ltt_event_metadata_statedump(struct ltt_session *session,
  94                                   struct ltt_channel *chan,
  95                                   struct ltt_event *event);
  96 static
  97 int _ltt_session_metadata_statedump(struct ltt_session *session);
  98
  99 int ltt_loglevel_match(const struct lttng_event_desc *desc,
 100                 enum lttng_ust_loglevel_type req_type,
 101                 int req_loglevel)
 102 {
 103         int ev_loglevel;
 104
 105         if (req_type == LTTNG_UST_LOGLEVEL_ALL)
 106                 return 1;
 107         if (!desc->loglevel)
 108                 ev_loglevel = TRACE_DEFAULT;
 109         else
 110                 ev_loglevel = *(*desc->loglevel);
 111         switch (req_type) {
 112         case LTTNG_UST_LOGLEVEL_RANGE:
 113                 if (ev_loglevel <= req_loglevel || req_loglevel == -1)
 114                         return 1;
 115                 else
 116                         return 0;
 117         case LTTNG_UST_LOGLEVEL_SINGLE:
 118                 if (ev_loglevel == req_loglevel || req_loglevel == -1)
 119                         return 1;
 120                 else
 121                         return 0;
 122         case LTTNG_UST_LOGLEVEL_ALL:
 123         default:
 124                 return 1;
 125         }
 126 }
 127
 128 /*
 129  * Return wildcard for a given event name if the event name match the
 130  * one of the wildcards.
 131  * Must be called with ust lock held.
 132  * Returns NULL if not present.
 133  */
 134 static
 135 struct wildcard_entry *match_wildcard(const struct lttng_event_desc *desc)
 136 {
 137         struct wildcard_entry *e;
 138
 139         cds_list_for_each_entry(e, &wildcard_list, list) {
 140                 /* If only contain '*' */
 141                 if (strlen(e->name) == 1)
 142                         goto possible_match;
 143                 /* Compare excluding final '*' */
 144                 if (!strncmp(desc->name, e->name, strlen(e->name) - 1))
 145                         goto possible_match;
 146                 continue;       /* goto next, no match */
 147         possible_match:
 148                 if (ltt_loglevel_match(desc,
 149                                 e->loglevel_type,
 150                                 e->loglevel)) {
 151                         return e;
 152                 }
 153                 /* no match, loop to next */
 154         }
 155         return NULL;
 156 }
 157
 158 /*
 159  * called at event creation if probe is missing.
 160  * called with session mutex held.
 161  */
 162 static
 163 int add_pending_probe(struct ltt_event *event, const char *name,
 164                 enum lttng_ust_loglevel_type loglevel_type,
 165                 int loglevel)
 166 {
 167         struct cds_hlist_head *head;
 168         struct ust_pending_probe *e;
 169         size_t name_len = strlen(name);
 170         uint32_t hash;
 171
 172         if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
 173                 WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
 174                 name_len = LTTNG_UST_SYM_NAME_LEN - 1;
 175         }
 176         hash = jhash(name, name_len, 0);
 177         head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
 178         e = zmalloc(sizeof(struct ust_pending_probe) + name_len);
 179         if (!e)
 180                 return -ENOMEM;
 181         memcpy(&e->name[0], name, name_len + 1);
 182         e->name[name_len] = '\0';
 183         e->loglevel_type = loglevel_type;
 184         e->loglevel = loglevel;
 185         cds_hlist_add_head(&e->node, head);
 186         e->event = event;
 187         event->pending_probe = e;
 188         return 0;
 189 }
 190
 191 /*
 192  * remove a pending probe. called when at event teardown and when an
 193  * event is fixed (probe is loaded).
 194  * called with session mutex held.
 195  */
 196 static
 197 void remove_pending_probe(struct ust_pending_probe *e)
 198 {
 199         if (!e)
 200                 return;
 201         cds_hlist_del(&e->node);
 202         free(e);
 203 }
 204
 205 /*
 206  * Called at library load: connect the probe on the events pending on
 207  * probe load.
 208  * called with session mutex held.
 209  */
 210 int pending_probe_fix_events(const struct lttng_event_desc *desc)
 211 {
 212         struct cds_hlist_head *head;
 213         struct cds_hlist_node *node, *p;
 214         struct ust_pending_probe *e;
 215         const char *name = desc->name;
 216         int ret = 0;
 217         struct lttng_ust_event event_param;
 218         size_t name_len = strlen(name);
 219         uint32_t hash;
 220
 221         /* Wildcard */
 222         {
 223                 struct wildcard_entry *wildcard;
 224
 225                 wildcard = match_wildcard(desc);
 226                 if (strcmp(desc->name, "lttng_ust:metadata") && wildcard) {
 227                         struct session_wildcard *sw;
 228
 229                         cds_list_for_each_entry(sw, &wildcard->session_list,
 230                                         session_list) {
 231                                 struct ltt_event *ev;
 232                                 int ret;
 233
 234                                 memcpy(&event_param, &sw->event_param,
 235                                                 sizeof(event_param));
 236                                 memcpy(event_param.name,
 237                                         desc->name,
 238                                         sizeof(event_param.name));
 239                                 /* create event */
 240                                 ret = ltt_event_create(sw->chan,
 241                                         &event_param, NULL,
 242                                         &ev);
 243                                 if (ret) {
 244                                         DBG("Error creating event");
 245                                         continue;
 246                                 }
 247                                 cds_list_add(&ev->wildcard_list,
 248                                         &sw->events);
 249                         }
 250                 }
 251         }
 252
 253         if (name_len > LTTNG_UST_SYM_NAME_LEN - 1) {
 254                 WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name, LTTNG_UST_SYM_NAME_LEN - 1);
 255                 name_len = LTTNG_UST_SYM_NAME_LEN - 1;
 256         }
 257         hash = jhash(name, name_len, 0);
 258         head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
 259         cds_hlist_for_each_entry_safe(e, node, p, head, node) {
 260                 struct ltt_event *event;
 261                 struct ltt_channel *chan;
 262
 263                 event = e->event;
 264                 if (!ltt_loglevel_match(event->desc,
 265                                 e->loglevel_type,
 266                                 e->loglevel)) {
 267                         continue;
 268                 }
 269                 if (strncmp(name, e->name, LTTNG_UST_SYM_NAME_LEN - 1)) {
 270                         continue;
 271                 }
 272                 chan = event->chan;
 273                 assert(!event->desc);
 274                 event->desc = desc;
 275                 event->pending_probe = NULL;
 276                 remove_pending_probe(e);
 277                 ret |= __tracepoint_probe_register(name,
 278                                 event->desc->probe_callback,
 279                                 event);
 280                 if (ret)
 281                         continue;
 282                 event->id = chan->free_event_id++;
 283                 ret |= _ltt_event_metadata_statedump(chan->session, chan,
 284                                 event);
 285         }
 286         return ret;
 287 }
 288
 289 void synchronize_trace(void)
 290 {
 291         synchronize_rcu();
 292 }
 293
 294 struct ltt_session *ltt_session_create(void)
 295 {
 296         struct ltt_session *session;
 297
 298         session = zmalloc(sizeof(struct ltt_session));
 299         if (!session)
 300                 return NULL;
 301         CDS_INIT_LIST_HEAD(&session->chan);
 302         CDS_INIT_LIST_HEAD(&session->events);
 303         CDS_INIT_LIST_HEAD(&session->wildcards);
 304         uuid_generate(session->uuid);
 305         cds_list_add(&session->list, &sessions);
 306         return session;
 307 }
 308
 309 void ltt_session_destroy(struct ltt_session *session)
 310 {
 311         struct ltt_channel *chan, *tmpchan;
 312         struct ltt_event *event, *tmpevent;
 313         struct session_wildcard *wildcard, *tmpwildcard;
 314         int ret;
 315
 316         CMM_ACCESS_ONCE(session->active) = 0;
 317         cds_list_for_each_entry(event, &session->events, list) {
 318                 ret = _ltt_event_unregister(event);
 319                 WARN_ON(ret);
 320         }
 321         synchronize_trace();    /* Wait for in-flight events to complete */
 322         cds_list_for_each_entry_safe(wildcard, tmpwildcard, &session->wildcards, list)
 323                 _ltt_wildcard_destroy(wildcard);
 324         cds_list_for_each_entry_safe(event, tmpevent, &session->events, list)
 325                 _ltt_event_destroy(event);
 326         cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
 327                 _ltt_channel_destroy(chan);
 328         cds_list_del(&session->list);
 329         free(session);
 330 }
 331
 332 int ltt_session_enable(struct ltt_session *session)
 333 {
 334         int ret = 0;
 335         struct ltt_channel *chan;
 336
 337         if (session->active) {
 338                 ret = -EBUSY;
 339                 goto end;
 340         }
 341
 342         /*
 343          * Snapshot the number of events per channel to know the type of header
 344          * we need to use.
 345          */
 346         cds_list_for_each_entry(chan, &session->chan, list) {
 347                 if (chan->header_type)
 348                         continue;               /* don't change it if session stop/restart */
 349                 if (chan->free_event_id < 31)
 350                         chan->header_type = 1;  /* compact */
 351                 else
 352                         chan->header_type = 2;  /* large */
 353         }
 354
 355         CMM_ACCESS_ONCE(session->active) = 1;
 356         CMM_ACCESS_ONCE(session->been_active) = 1;
 357         ret = _ltt_session_metadata_statedump(session);
 358         if (ret)
 359                 CMM_ACCESS_ONCE(session->active) = 0;
 360 end:
 361         return ret;
 362 }
 363
 364 int ltt_session_disable(struct ltt_session *session)
 365 {
 366         int ret = 0;
 367
 368         if (!session->active) {
 369                 ret = -EBUSY;
 370                 goto end;
 371         }
 372         CMM_ACCESS_ONCE(session->active) = 0;
 373 end:
 374         return ret;
 375 }
 376
 377 int ltt_channel_enable(struct ltt_channel *channel)
 378 {
 379         int old;
 380
 381         if (channel == channel->session->metadata)
 382                 return -EPERM;
 383         old = uatomic_xchg(&channel->enabled, 1);
 384         if (old)
 385                 return -EEXIST;
 386         return 0;
 387 }
 388
 389 int ltt_channel_disable(struct ltt_channel *channel)
 390 {
 391         int old;
 392
 393         if (channel == channel->session->metadata)
 394                 return -EPERM;
 395         old = uatomic_xchg(&channel->enabled, 0);
 396         if (!old)
 397                 return -EEXIST;
 398         return 0;
 399 }
 400
 401 int ltt_event_enable(struct ltt_event *event)
 402 {
 403         int old;
 404
 405         if (event->chan == event->chan->session->metadata)
 406                 return -EPERM;
 407         old = uatomic_xchg(&event->enabled, 1);
 408         if (old)
 409                 return -EEXIST;
 410         return 0;
 411 }
 412
 413 int ltt_event_disable(struct ltt_event *event)
 414 {
 415         int old;
 416
 417         if (event->chan == event->chan->session->metadata)
 418                 return -EPERM;
 419         old = uatomic_xchg(&event->enabled, 0);
 420         if (!old)
 421                 return -EEXIST;
 422         return 0;
 423 }
 424
 425 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 426                                        const char *transport_name,
 427                                        void *buf_addr,
 428                                        size_t subbuf_size, size_t num_subbuf,
 429                                        unsigned int switch_timer_interval,
 430                                        unsigned int read_timer_interval,
 431                                        int **shm_fd, int **wait_fd,
 432                                        uint64_t **memory_map_size,
 433                                        struct ltt_channel *chan_priv_init)
 434 {
 435         struct ltt_channel *chan = NULL;
 436         struct ltt_transport *transport;
 437
 438         if (session->been_active)
 439                 goto active;    /* Refuse to add channel to active session */
 440         transport = ltt_transport_find(transport_name);
 441         if (!transport) {
 442                 DBG("LTTng transport %s not found\n",
 443                        transport_name);
 444                 goto notransport;
 445         }
 446         chan_priv_init->id = session->free_chan_id++;
 447         chan_priv_init->session = session;
 448         /*
 449          * Note: the channel creation op already writes into the packet
 450          * headers. Therefore the "chan" information used as input
 451          * should be already accessible.
 452          */
 453         chan = transport->ops.channel_create("[lttng]", buf_addr,
 454                         subbuf_size, num_subbuf, switch_timer_interval,
 455                         read_timer_interval, shm_fd, wait_fd,
 456                         memory_map_size, chan_priv_init);
 457         if (!chan)
 458                 goto create_error;
 459         chan->enabled = 1;
 460         chan->ops = &transport->ops;
 461         cds_list_add(&chan->list, &session->chan);
 462         return chan;
 463
 464 create_error:
 465 notransport:
 466 active:
 467         return NULL;
 468 }
 469
 470 /*
 471  * Only used internally at session destruction.
 472  */
 473 static
 474 void _ltt_channel_destroy(struct ltt_channel *chan)
 475 {
 476         cds_list_del(&chan->list);
 477         lttng_destroy_context(chan->ctx);
 478         chan->ops->channel_destroy(chan);
 479 }
 480
 481 /*
 482  * Supports event creation while tracing session is active.
 483  */
 484 int ltt_event_create(struct ltt_channel *chan,
 485                 struct lttng_ust_event *event_param,
 486                 void *filter,
 487                 struct ltt_event **_event)
 488 {
 489         const struct lttng_event_desc *desc = NULL;     /* silence gcc */
 490         struct ltt_event *event;
 491         int ret = 0;
 492
 493         if (chan->used_event_id == -1UL) {
 494                 ret = -ENOMEM;
 495                 goto full;
 496         }
 497         /*
 498          * This is O(n^2) (for each event, the loop is called at event
 499          * creation). Might require a hash if we have lots of events.
 500          */
 501         cds_list_for_each_entry(event, &chan->session->events, list) {
 502                 if (event->desc && !strncmp(event->desc->name,
 503                                 event_param->name,
 504                                 LTTNG_UST_SYM_NAME_LEN - 1)) {
 505                         ret = -EEXIST;
 506                         goto exist;
 507                 }
 508         }
 509
 510         /*
 511          * Check if loglevel match. Refuse to connect event if not.
 512          */
 513         if (event_param->instrumentation == LTTNG_UST_TRACEPOINT) {
 514                 desc = ltt_event_get(event_param->name);
 515                 if (!ltt_loglevel_match(desc,
 516                                 event_param->loglevel_type,
 517                                 event_param->loglevel)) {
 518                         ret = -EPERM;
 519                         goto no_loglevel_match;
 520                 }
 521         }
 522         event = zmalloc(sizeof(struct ltt_event));
 523         if (!event) {
 524                 ret = -ENOMEM;
 525                 goto cache_error;
 526         }
 527         event->chan = chan;
 528         event->filter = filter;
 529         /*
 530          * used_event_id counts the maximum number of event IDs that can
 531          * register if all probes register.
 532          */
 533         chan->used_event_id++;
 534         event->enabled = 1;
 535         event->instrumentation = event_param->instrumentation;
 536         /* Populate ltt_event structure before tracepoint registration. */
 537         cmm_smp_wmb();
 538         switch (event_param->instrumentation) {
 539         case LTTNG_UST_TRACEPOINT:
 540                 event->desc = desc;
 541                 if (event->desc) {
 542                         ret = __tracepoint_probe_register(event_param->name,
 543                                         event->desc->probe_callback,
 544                                         event);
 545                         if (ret)
 546                                 goto register_error;
 547                         event->id = chan->free_event_id++;
 548                 } else {
 549                         /*
 550                          * If the probe is not present, event->desc stays NULL,
 551                          * waiting for the probe to register, and the event->id
 552                          * stays unallocated.
 553                          */
 554                         ret = add_pending_probe(event, event_param->name,
 555                                         event_param->loglevel_type,
 556                                         event_param->loglevel);
 557                         if (ret)
 558                                 goto add_pending_error;
 559                 }
 560                 break;
 561         default:
 562                 WARN_ON_ONCE(1);
 563         }
 564         if (event->desc) {
 565                 ret = _ltt_event_metadata_statedump(chan->session, chan, event);
 566                 if (ret)
 567                         goto statedump_error;
 568         }
 569         cds_list_add(&event->list, &chan->session->events);
 570         *_event = event;
 571         return 0;
 572
 573 statedump_error:
 574         if (event->desc) {
 575                 WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name,
 576                                         event->desc->probe_callback,
 577                                         event));
 578                 ltt_event_put(event->desc);
 579         }
 580 add_pending_error:
 581 register_error:
 582         free(event);
 583 cache_error:
 584 no_loglevel_match:
 585 exist:
 586 full:
 587         return ret;
 588 }
 589
 590 /*
 591  * Only used internally at session destruction.
 592  */
 593 int _ltt_event_unregister(struct ltt_event *event)
 594 {
 595         int ret = -EINVAL;
 596
 597         switch (event->instrumentation) {
 598         case LTTNG_UST_TRACEPOINT:
 599                 if (event->desc) {
 600                         ret = __tracepoint_probe_unregister(event->desc->name,
 601                                                           event->desc->probe_callback,
 602                                                           event);
 603                         if (ret)
 604                                 return ret;
 605                 } else {
 606                         remove_pending_probe(event->pending_probe);
 607                         ret = 0;
 608                 }
 609                 break;
 610         default:
 611                 WARN_ON_ONCE(1);
 612         }
 613         return ret;
 614 }
 615
 616 /*
 617  * Only used internally at session destruction.
 618  */
 619 static
 620 void _ltt_event_destroy(struct ltt_event *event)
 621 {
 622         switch (event->instrumentation) {
 623         case LTTNG_UST_TRACEPOINT:
 624                 if (event->desc) {
 625                         ltt_event_put(event->desc);
 626                 }
 627                 break;
 628         default:
 629                 WARN_ON_ONCE(1);
 630         }
 631         cds_list_del(&event->list);
 632         lttng_destroy_context(event->ctx);
 633         free(event);
 634 }
 635
 636 /*
 637  * We have exclusive access to our metadata buffer (protected by the
 638  * ust_lock), so we can do racy operations such as looking for
 639  * remaining space left in packet and write, since mutual exclusion
 640  * protects us from concurrent writes.
 641  */
 642 int lttng_metadata_printf(struct ltt_session *session,
 643                           const char *fmt, ...)
 644 {
 645         struct lttng_ust_lib_ring_buffer_ctx ctx;
 646         struct ltt_channel *chan = session->metadata;
 647         char *str = NULL;
 648         int ret = 0, waitret;
 649         size_t len, reserve_len, pos;
 650         va_list ap;
 651
 652         WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active));
 653
 654         va_start(ap, fmt);
 655         ret = vasprintf(&str, fmt, ap);
 656         va_end(ap);
 657         if (ret < 0)
 658                 return -ENOMEM;
 659
 660         len = strlen(str);
 661         pos = 0;
 662
 663         for (pos = 0; pos < len; pos += reserve_len) {
 664                 reserve_len = min_t(size_t,
 665                                 chan->ops->packet_avail_size(chan->chan, chan->handle),
 666                                 len - pos);
 667                 lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
 668                                          sizeof(char), -1, chan->handle);
 669                 /*
 670                  * We don't care about metadata buffer's records lost
 671                  * count, because we always retry here. Report error if
 672                  * we need to bail out after timeout or being
 673                  * interrupted.
 674                  */
 675                 waitret = wait_cond_interruptible_timeout(
 676                         ({
 677                                 ret = chan->ops->event_reserve(&ctx, 0);
 678                                 ret != -ENOBUFS || !ret;
 679                         }),
 680                         LTTNG_METADATA_TIMEOUT_MSEC);
 681                 if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) {
 682                         DBG("LTTng: Failure to write metadata to buffers (%s)\n",
 683                                 waitret == -EINTR ? "interrupted" :
 684                                         (ret == -ENOBUFS ? "timeout" : "I/O error"));
 685                         if (waitret == -EINTR)
 686                                 ret = waitret;
 687                         goto end;
 688                 }
 689                 chan->ops->event_write(&ctx, &str[pos], reserve_len);
 690                 chan->ops->event_commit(&ctx);
 691         }
 692 end:
 693         free(str);
 694         return ret;
 695 }
 696
 697 static
 698 int _ltt_field_statedump(struct ltt_session *session,
 699                          const struct lttng_event_field *field)
 700 {
 701         int ret = 0;
 702
 703         switch (field->type.atype) {
 704         case atype_integer:
 705                 ret = lttng_metadata_printf(session,
 706                         "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
 707                         field->type.u.basic.integer.size,
 708                         field->type.u.basic.integer.alignment,
 709                         field->type.u.basic.integer.signedness,
 710                         (field->type.u.basic.integer.encoding == lttng_encode_none)
 711                                 ? "none"
 712                                 : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
 713                                         ? "UTF8"
 714                                         : "ASCII",
 715                         field->type.u.basic.integer.base,
 716 #if (BYTE_ORDER == BIG_ENDIAN)
 717                         field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
 718 #else
 719                         field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 720 #endif
 721                         field->name);
 722                 break;
 723         case atype_float:
 724                 ret = lttng_metadata_printf(session,
 725                         "               floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
 726                         field->type.u.basic._float.exp_dig,
 727                         field->type.u.basic._float.mant_dig,
 728                         field->type.u.basic._float.alignment,
 729 #if (BYTE_ORDER == BIG_ENDIAN)
 730                         field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
 731 #else
 732                         field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 733 #endif
 734                         field->name);
 735                 break;
 736         case atype_enum:
 737                 ret = lttng_metadata_printf(session,
 738                         "               %s %s;\n",
 739                         field->type.u.basic.enumeration.name,
 740                         field->name);
 741                 break;
 742         case atype_array:
 743         {
 744                 const struct lttng_basic_type *elem_type;
 745
 746                 elem_type = &field->type.u.array.elem_type;
 747                 ret = lttng_metadata_printf(session,
 748                         "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
 749                         elem_type->u.basic.integer.size,
 750                         elem_type->u.basic.integer.alignment,
 751                         elem_type->u.basic.integer.signedness,
 752                         (elem_type->u.basic.integer.encoding == lttng_encode_none)
 753                                 ? "none"
 754                                 : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
 755                                         ? "UTF8"
 756                                         : "ASCII",
 757                         elem_type->u.basic.integer.base,
 758 #if (BYTE_ORDER == BIG_ENDIAN)
 759                         elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
 760 #else
 761                         elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 762 #endif
 763                         field->name, field->type.u.array.length);
 764                 break;
 765         }
 766         case atype_sequence:
 767         {
 768                 const struct lttng_basic_type *elem_type;
 769                 const struct lttng_basic_type *length_type;
 770
 771                 elem_type = &field->type.u.sequence.elem_type;
 772                 length_type = &field->type.u.sequence.length_type;
 773                 ret = lttng_metadata_printf(session,
 774                         "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
 775                         length_type->u.basic.integer.size,
 776                         (unsigned int) length_type->u.basic.integer.alignment,
 777                         length_type->u.basic.integer.signedness,
 778                         (length_type->u.basic.integer.encoding == lttng_encode_none)
 779                                 ? "none"
 780                                 : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
 781                                         ? "UTF8"
 782                                         : "ASCII"),
 783                         length_type->u.basic.integer.base,
 784 #if (BYTE_ORDER == BIG_ENDIAN)
 785                         length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
 786 #else
 787                         length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 788 #endif
 789                         field->name);
 790                 if (ret)
 791                         return ret;
 792
 793                 ret = lttng_metadata_printf(session,
 794                         "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
 795                         elem_type->u.basic.integer.size,
 796                         (unsigned int) elem_type->u.basic.integer.alignment,
 797                         elem_type->u.basic.integer.signedness,
 798                         (elem_type->u.basic.integer.encoding == lttng_encode_none)
 799                                 ? "none"
 800                                 : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
 801                                         ? "UTF8"
 802                                         : "ASCII"),
 803                         elem_type->u.basic.integer.base,
 804 #if (BYTE_ORDER == BIG_ENDIAN)
 805                         elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
 806 #else
 807                         elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 808 #endif
 809                         field->name,
 810                         field->name);
 811                 break;
 812         }
 813
 814         case atype_string:
 815                 /* Default encoding is UTF8 */
 816                 ret = lttng_metadata_printf(session,
 817                         "               string%s _%s;\n",
 818                         field->type.u.basic.string.encoding == lttng_encode_ASCII ?
 819                                 " { encoding = ASCII; }" : "",
 820                         field->name);
 821                 break;
 822         default:
 823                 WARN_ON_ONCE(1);
 824                 return -EINVAL;
 825         }
 826         return ret;
 827 }
 828
 829 static
 830 int _ltt_context_metadata_statedump(struct ltt_session *session,
 831                                     struct lttng_ctx *ctx)
 832 {
 833         int ret = 0;
 834         int i;
 835
 836         if (!ctx)
 837                 return 0;
 838         for (i = 0; i < ctx->nr_fields; i++) {
 839                 const struct lttng_ctx_field *field = &ctx->fields[i];
 840
 841                 ret = _ltt_field_statedump(session, &field->event_field);
 842                 if (ret)
 843                         return ret;
 844         }
 845         return ret;
 846 }
 847
 848 static
 849 int _ltt_fields_metadata_statedump(struct ltt_session *session,
 850                                    struct ltt_event *event)
 851 {
 852         const struct lttng_event_desc *desc = event->desc;
 853         int ret = 0;
 854         int i;
 855
 856         for (i = 0; i < desc->nr_fields; i++) {
 857                 const struct lttng_event_field *field = &desc->fields[i];
 858
 859                 ret = _ltt_field_statedump(session, field);
 860                 if (ret)
 861                         return ret;
 862         }
 863         return ret;
 864 }
 865
 866 static
 867 int _ltt_event_metadata_statedump(struct ltt_session *session,
 868                                   struct ltt_channel *chan,
 869                                   struct ltt_event *event)
 870 {
 871         int ret = 0;
 872
 873         if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active))
 874                 return 0;
 875         if (chan == session->metadata)
 876                 return 0;
 877         /*
 878          * Don't print events for which probe load is pending.
 879          */
 880         if (!event->desc)
 881                 return 0;
 882
 883         ret = lttng_metadata_printf(session,
 884                 "event {\n"
 885                 "       name = \"%s\";\n"
 886                 "       id = %u;\n"
 887                 "       stream_id = %u;\n",
 888                 event->desc->name,
 889                 event->id,
 890                 event->chan->id);
 891         if (ret)
 892                 goto end;
 893
 894         if (event->desc->loglevel) {
 895                 ret = lttng_metadata_printf(session,
 896                         "       loglevel = %d;\n",
 897                         *(*event->desc->loglevel));
 898                 if (ret)
 899                         goto end;
 900         }
 901
 902         if (event->ctx) {
 903                 ret = lttng_metadata_printf(session,
 904                         "       context := struct {\n");
 905                 if (ret)
 906                         goto end;
 907         }
 908         ret = _ltt_context_metadata_statedump(session, event->ctx);
 909         if (ret)
 910                 goto end;
 911         if (event->ctx) {
 912                 ret = lttng_metadata_printf(session,
 913                         "       };\n");
 914                 if (ret)
 915                         goto end;
 916         }
 917
 918         ret = lttng_metadata_printf(session,
 919                 "       fields := struct {\n"
 920                 );
 921         if (ret)
 922                 goto end;
 923
 924         ret = _ltt_fields_metadata_statedump(session, event);
 925         if (ret)
 926                 goto end;
 927
 928         /*
 929          * LTTng space reservation can only reserve multiples of the
 930          * byte size.
 931          */
 932         ret = lttng_metadata_printf(session,
 933                 "       };\n"
 934                 "};\n\n");
 935         if (ret)
 936                 goto end;
 937
 938         event->metadata_dumped = 1;
 939 end:
 940         return ret;
 941
 942 }
 943
 944 static
 945 int _ltt_channel_metadata_statedump(struct ltt_session *session,
 946                                     struct ltt_channel *chan)
 947 {
 948         int ret = 0;
 949
 950         if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active))
 951                 return 0;
 952         if (chan == session->metadata)
 953                 return 0;
 954
 955         WARN_ON_ONCE(!chan->header_type);
 956         ret = lttng_metadata_printf(session,
 957                 "stream {\n"
 958                 "       id = %u;\n"
 959                 "       event.header := %s;\n"
 960                 "       packet.context := struct packet_context;\n",
 961                 chan->id,
 962                 chan->header_type == 1 ? "struct event_header_compact" :
 963                         "struct event_header_large");
 964         if (ret)
 965                 goto end;
 966
 967         if (chan->ctx) {
 968                 ret = lttng_metadata_printf(session,
 969                         "       event.context := struct {\n");
 970                 if (ret)
 971                         goto end;
 972         }
 973         ret = _ltt_context_metadata_statedump(session, chan->ctx);
 974         if (ret)
 975                 goto end;
 976         if (chan->ctx) {
 977                 ret = lttng_metadata_printf(session,
 978                         "       };\n");
 979                 if (ret)
 980                         goto end;
 981         }
 982
 983         ret = lttng_metadata_printf(session,
 984                 "};\n\n");
 985
 986         chan->metadata_dumped = 1;
 987 end:
 988         return ret;
 989 }
 990
 991 static
 992 int _ltt_stream_packet_context_declare(struct ltt_session *session)
 993 {
 994         return lttng_metadata_printf(session,
 995                 "struct packet_context {\n"
 996                 "       uint64_clock_monotonic_t timestamp_begin;\n"
 997                 "       uint64_clock_monotonic_t timestamp_end;\n"
 998                 "       uint32_t events_discarded;\n"
 999                 "       uint32_t content_size;\n"
1000                 "       uint32_t packet_size;\n"
1001                 "       uint32_t cpu_id;\n"
1002                 "};\n\n"
1003                 );
1004 }
1005
1006 /*
1007  * Compact header:
1008  * id: range: 0 - 30.
1009  * id 31 is reserved to indicate an extended header.
1010  *
1011  * Large header:
1012  * id: range: 0 - 65534.
1013  * id 65535 is reserved to indicate an extended header.
1014  */
1015 static
1016 int _ltt_event_header_declare(struct ltt_session *session)
1017 {
1018         return lttng_metadata_printf(session,
1019         "struct event_header_compact {\n"
1020         "       enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1021         "       variant <id> {\n"
1022         "               struct {\n"
1023         "                       uint27_clock_monotonic_t timestamp;\n"
1024         "               } compact;\n"
1025         "               struct {\n"
1026         "                       uint32_t id;\n"
1027         "                       uint64_clock_monotonic_t timestamp;\n"
1028         "               } extended;\n"
1029         "       } v;\n"
1030         "} align(%u);\n"
1031         "\n"
1032         "struct event_header_large {\n"
1033         "       enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1034         "       variant <id> {\n"
1035         "               struct {\n"
1036         "                       uint32_clock_monotonic_t timestamp;\n"
1037         "               } compact;\n"
1038         "               struct {\n"
1039         "                       uint32_t id;\n"
1040         "                       uint64_clock_monotonic_t timestamp;\n"
1041         "               } extended;\n"
1042         "       } v;\n"
1043         "} align(%u);\n\n",
1044         lttng_alignof(uint32_t) * CHAR_BIT,
1045         lttng_alignof(uint16_t) * CHAR_BIT
1046         );
1047 }
1048
1049 /*
1050  * Approximation of NTP time of day to clock monotonic correlation,
1051  * taken at start of trace.
1052  * Yes, this is only an approximation. Yes, we can (and will) do better
1053  * in future versions.
1054  */
1055 static
1056 uint64_t measure_clock_offset(void)
1057 {
1058         uint64_t offset, monotonic[2], realtime;
1059         struct timespec rts = { 0, 0 };
1060         int ret;
1061
1062         monotonic[0] = trace_clock_read64();
1063         ret = clock_gettime(CLOCK_REALTIME, &rts);
1064         if (ret < 0)
1065                 return 0;
1066         monotonic[1] = trace_clock_read64();
1067         offset = (monotonic[0] + monotonic[1]) >> 1;
1068         realtime = rts.tv_sec * 1000000000ULL;
1069         realtime += rts.tv_nsec;
1070         offset = realtime - offset;
1071         return offset;
1072 }
1073
1074 /*
1075  * Output metadata into this session's metadata buffers.
1076  */
1077 static
1078 int _ltt_session_metadata_statedump(struct ltt_session *session)
1079 {
1080         unsigned char *uuid_c = session->uuid;
1081         char uuid_s[37], clock_uuid_s[CLOCK_UUID_LEN];
1082         struct ltt_channel *chan;
1083         struct ltt_event *event;
1084         int ret = 0;
1085
1086         if (!CMM_ACCESS_ONCE(session->active))
1087                 return 0;
1088         if (session->metadata_dumped)
1089                 goto skip_session;
1090         if (!session->metadata) {
1091                 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1092                 return -EPERM;
1093         }
1094
1095         snprintf(uuid_s, sizeof(uuid_s),
1096                 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1097                 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
1098                 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
1099                 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
1100                 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
1101
1102         ret = lttng_metadata_printf(session,
1103                 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1104                 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1105                 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1106                 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1107                 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1108                 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1109                 "\n"
1110                 "trace {\n"
1111                 "       major = %u;\n"
1112                 "       minor = %u;\n"
1113                 "       uuid = \"%s\";\n"
1114                 "       byte_order = %s;\n"
1115                 "       packet.header := struct {\n"
1116                 "               uint32_t magic;\n"
1117                 "               uint8_t  uuid[16];\n"
1118                 "               uint32_t stream_id;\n"
1119                 "       };\n"
1120                 "};\n\n",
1121                 lttng_alignof(uint8_t) * CHAR_BIT,
1122                 lttng_alignof(uint16_t) * CHAR_BIT,
1123                 lttng_alignof(uint32_t) * CHAR_BIT,
1124                 lttng_alignof(uint64_t) * CHAR_BIT,
1125                 CTF_VERSION_MAJOR,
1126                 CTF_VERSION_MINOR,
1127                 uuid_s,
1128 #if (BYTE_ORDER == BIG_ENDIAN)
1129                 "be"
1130 #else
1131                 "le"
1132 #endif
1133                 );
1134         if (ret)
1135                 goto end;
1136
1137         ret = lttng_metadata_printf(session,
1138                 "clock {\n"
1139                 "       name = %s;\n",
1140                 "monotonic"
1141                 );
1142         if (ret)
1143                 goto end;
1144
1145         if (!trace_clock_uuid(clock_uuid_s)) {
1146                 ret = lttng_metadata_printf(session,
1147                         "       uuid = \"%s\";\n",
1148                         clock_uuid_s
1149                         );
1150                 if (ret)
1151                         goto end;
1152         }
1153
1154         ret = lttng_metadata_printf(session,
1155                 "       description = \"Monotonic Clock\";\n"
1156                 "       freq = %" PRIu64 "; /* Frequency, in Hz */\n"
1157                 "       /* clock value offset from Epoch is: offset * (1/freq) */\n"
1158                 "       offset = %" PRIu64 ";\n"
1159                 "};\n\n",
1160                 trace_clock_freq(),
1161                 measure_clock_offset()
1162                 );
1163         if (ret)
1164                 goto end;
1165
1166         ret = lttng_metadata_printf(session,
1167                 "typealias integer {\n"
1168                 "       size = 27; align = 1; signed = false;\n"
1169                 "       map = clock.monotonic.value;\n"
1170                 "} := uint27_clock_monotonic_t;\n"
1171                 "\n"
1172                 "typealias integer {\n"
1173                 "       size = 32; align = %u; signed = false;\n"
1174                 "       map = clock.monotonic.value;\n"
1175                 "} := uint32_clock_monotonic_t;\n"
1176                 "\n"
1177                 "typealias integer {\n"
1178                 "       size = 64; align = %u; signed = false;\n"
1179                 "       map = clock.monotonic.value;\n"
1180                 "} := uint64_clock_monotonic_t;\n\n",
1181                 lttng_alignof(uint32_t) * CHAR_BIT,
1182                 lttng_alignof(uint64_t) * CHAR_BIT
1183                 );
1184         if (ret)
1185                 goto end;
1186
1187         ret = _ltt_stream_packet_context_declare(session);
1188         if (ret)
1189                 goto end;
1190
1191         ret = _ltt_event_header_declare(session);
1192         if (ret)
1193                 goto end;
1194
1195 skip_session:
1196         cds_list_for_each_entry(chan, &session->chan, list) {
1197                 ret = _ltt_channel_metadata_statedump(session, chan);
1198                 if (ret)
1199                         goto end;
1200         }
1201
1202         cds_list_for_each_entry(event, &session->events, list) {
1203                 ret = _ltt_event_metadata_statedump(session, event->chan, event);
1204                 if (ret)
1205                         goto end;
1206         }
1207         session->metadata_dumped = 1;
1208 end:
1209         return ret;
1210 }
1211
1212 void lttng_ust_events_exit(void)
1213 {
1214         struct ltt_session *session, *tmpsession;
1215
1216         cds_list_for_each_entry_safe(session, tmpsession, &sessions, list)
1217                 ltt_session_destroy(session);
1218 }
1219
1220 /* WILDCARDS */
1221
1222 static
1223 int wildcard_same_loglevel(struct wildcard_entry *e,
1224         enum lttng_ust_loglevel_type loglevel_type,
1225         int loglevel)
1226 {
1227         if (e->loglevel_type == loglevel_type && e->loglevel == loglevel)
1228                 return 1;
1229         else
1230                 return 0;
1231 }
1232
1233 #if 0
1234 static
1235 int wildcard_is_within(struct wildcard_entry *e,
1236         enum lttng_ust_loglevel_type loglevel_type,
1237         int loglevel)
1238 {
1239         if (e->loglevel_type == LTTNG_UST_LOGLEVEL_ALL
1240                         || e->loglevel == -1)
1241                 return 1;
1242         switch (e->loglevel_type) {
1243         case LTTNG_UST_LOGLEVEL_RANGE:
1244                 switch (loglevel_type) {
1245                 case LTTNG_UST_LOGLEVEL_RANGE:
1246                         if (e->loglevel >= loglevel)
1247                                 return 1;
1248                         else
1249                                 return 0;
1250                 case LTTNG_UST_LOGLEVEL_SINGLE:
1251                         if (e->loglevel <= 0 && loglevel == 0)
1252                                 return 1;
1253                         else
1254                                 return 0;
1255                 }
1256         case LTTNG_UST_LOGLEVEL_SINGLE:
1257                 switch (loglevel_type) {
1258                 case LTTNG_UST_LOGLEVEL_RANGE:
1259                         if (loglevel <= 0)
1260                                 return 1;
1261                         else
1262                                 return 0;
1263                 case LTTNG_UST_LOGLEVEL_SINGLE:
1264                         if (e->loglevel == loglevel)
1265                                 return 1;
1266                         else
1267                                 return 0;
1268                 }
1269         }
1270 }
1271 #endif
1272
1273 /*
1274  * Add the wildcard to the wildcard list. Must be called with
1275  * ust lock held.
1276  */
1277 static
1278 struct session_wildcard *add_wildcard(struct ltt_channel *chan,
1279         struct lttng_ust_event *event_param)
1280 {
1281         struct wildcard_entry *e;
1282         struct session_wildcard *sw;
1283         size_t name_len = strlen(event_param->name) + 1;
1284         int found = 0;
1285
1286         /*
1287          * Try to find global wildcard entry. Given that this is shared
1288          * across all sessions, we need to check for exact loglevel
1289          * match, not just whether contained within the existing ones.
1290          */
1291         cds_list_for_each_entry(e, &wildcard_list, list) {
1292                 if (!strncmp(event_param->name, e->name,
1293                                 LTTNG_UST_SYM_NAME_LEN - 1)) {
1294                         if (wildcard_same_loglevel(e,
1295                                         event_param->loglevel_type,
1296                                         event_param->loglevel)) {
1297                                 found = 1;
1298                                 break;
1299                         }
1300                 }
1301         }
1302
1303         if (!found) {
1304                 /*
1305                  * Create global wildcard entry if not found. Using
1306                  * zmalloc here to allocate a variable length element.
1307                  * Could cause some memory fragmentation if overused.
1308                  */
1309                 e = zmalloc(sizeof(struct wildcard_entry) + name_len);
1310                 if (!e)
1311                         return ERR_PTR(-ENOMEM);
1312                 memcpy(&e->name[0], event_param->name, name_len);
1313                 cds_list_add(&e->list, &wildcard_list);
1314                 CDS_INIT_LIST_HEAD(&e->session_list);
1315         }
1316
1317         /* session wildcard */
1318         cds_list_for_each_entry(sw, &e->session_list, session_list) {
1319                 if (chan == sw->chan) {
1320                         DBG("wildcard %s busy for this channel",
1321                                 event_param->name);
1322                         return ERR_PTR(-EEXIST);        /* Already there */
1323                 }
1324         }
1325         sw = zmalloc(sizeof(struct session_wildcard));
1326         if (!sw)
1327                 return ERR_PTR(-ENOMEM);
1328         sw->chan = chan;
1329         sw->enabled = 1;
1330         memcpy(&sw->event_param, event_param, sizeof(sw->event_param));
1331         sw->event_param.instrumentation = LTTNG_UST_TRACEPOINT;
1332         sw->event_param.loglevel_type = event_param->loglevel_type;
1333         sw->event_param.loglevel = event_param->loglevel;
1334         CDS_INIT_LIST_HEAD(&sw->events);
1335         cds_list_add(&sw->list, &chan->session->wildcards);
1336         cds_list_add(&sw->session_list, &e->session_list);
1337         sw->entry = e;
1338         ltt_probes_create_wildcard_events(e, sw);
1339         return sw;
1340 }
1341
1342 /*
1343  * Remove the wildcard from the wildcard list. Must be called with
1344  * ust_lock held. Only called at session teardown.
1345  */
1346 static
1347 void _remove_wildcard(struct session_wildcard *wildcard)
1348 {
1349         struct ltt_event *ev, *tmp;
1350
1351         /*
1352          * Just remove the events owned (for enable/disable) by this
1353          * wildcard from the list. The session teardown will take care
1354          * of freeing the event memory.
1355          */
1356         cds_list_for_each_entry_safe(ev, tmp, &wildcard->events,
1357                         wildcard_list) {
1358                 cds_list_del(&ev->wildcard_list);
1359         }
1360         cds_list_del(&wildcard->session_list);
1361         cds_list_del(&wildcard->list);
1362         if (cds_list_empty(&wildcard->entry->session_list)) {
1363                 cds_list_del(&wildcard->entry->list);
1364                 free(wildcard->entry);
1365         }
1366         free(wildcard);
1367 }
1368
1369 int ltt_wildcard_create(struct ltt_channel *chan,
1370         struct lttng_ust_event *event_param,
1371         struct session_wildcard **_sw)
1372 {
1373         struct session_wildcard *sw;
1374
1375         sw = add_wildcard(chan, event_param);
1376         if (!sw || IS_ERR(sw)) {
1377                 return PTR_ERR(sw);
1378         }
1379         *_sw = sw;
1380         return 0;
1381 }
1382
1383 static
1384 void _ltt_wildcard_destroy(struct session_wildcard *sw)
1385 {
1386         _remove_wildcard(sw);
1387 }
1388
1389 int ltt_wildcard_enable(struct session_wildcard *wildcard)
1390 {
1391         struct ltt_event *ev;
1392         int ret;
1393
1394         if (wildcard->enabled)
1395                 return -EEXIST;
1396         cds_list_for_each_entry(ev, &wildcard->events, wildcard_list) {
1397                 ret = ltt_event_enable(ev);
1398                 if (ret) {
1399                         DBG("Error: enable error.\n");
1400                         return ret;
1401                 }
1402         }
1403         wildcard->enabled = 1;
1404         return 0;
1405 }
1406
1407 int ltt_wildcard_disable(struct session_wildcard *wildcard)
1408 {
1409         struct ltt_event *ev;
1410         int ret;
1411
1412         if (!wildcard->enabled)
1413                 return -EEXIST;
1414         cds_list_for_each_entry(ev, &wildcard->events, wildcard_list) {
1415                 ret = ltt_event_disable(ev);
1416                 if (ret) {
1417                         DBG("Error: disable error.\n");
1418                         return ret;
1419                 }
1420         }
1421         wildcard->enabled = 0;
1422         return 0;
1423 }