src/bin/lttng-sessiond/trace-ust.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _LGPL_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <inttypes.h>
  25
  26 #include <common/common.h>
  27 #include <common/defaults.h>
  28
  29 #include "buffer-registry.h"
  30 #include "trace-ust.h"
  31 #include "utils.h"
  32 #include "ust-app.h"
  33 #include "agent.h"
  34 #include "tracker.h"
  35
  36 /*
  37  * Match function for the events hash table lookup.
  38  *
  39  * Matches by name only. Used by the disable command.
  40  */
  41 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  42                 const void *_key)
  43 {
  44         struct ltt_ust_event *event;
  45         const char *name;
  46
  47         assert(node);
  48         assert(_key);
  49
  50         event = caa_container_of(node, struct ltt_ust_event, node.node);
  51         name = _key;
  52
  53         /* Event name */
  54         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  55                 goto no_match;
  56         }
  57
  58         /* Match */
  59         return 1;
  60
  61 no_match:
  62         return 0;
  63 }
  64
  65 /*
  66  * Match function for the hash table lookup.
  67  *
  68  * It matches an ust event based on three attributes which are the event name,
  69  * the filter bytecode and the loglevel.
  70  */
  71 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  72 {
  73         struct ltt_ust_event *event;
  74         const struct ltt_ust_ht_key *key;
  75         int ev_loglevel_value;
  76         int ll_match;
  77
  78         assert(node);
  79         assert(_key);
  80
  81         event = caa_container_of(node, struct ltt_ust_event, node.node);
  82         key = _key;
  83         ev_loglevel_value = event->attr.loglevel;
  84
  85         /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
  86
  87         /* Event name */
  88         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  89                 goto no_match;
  90         }
  91
  92         /* Event loglevel value and type. */
  93         ll_match = loglevels_match(event->attr.loglevel_type,
  94                 ev_loglevel_value, key->loglevel_type,
  95                 key->loglevel_value, LTTNG_UST_LOGLEVEL_ALL);
  96
  97         if (!ll_match) {
  98                 goto no_match;
  99         }
 100
 101         /* Only one of the filters is NULL, fail. */
 102         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 103                 goto no_match;
 104         }
 105
 106         if (key->filter && event->filter) {
 107                 /* Both filters exists, check length followed by the bytecode. */
 108                 if (event->filter->len != key->filter->len ||
 109                                 memcmp(event->filter->data, key->filter->data,
 110                                         event->filter->len) != 0) {
 111                         goto no_match;
 112                 }
 113         }
 114
 115         /* If only one of the exclusions is NULL, fail. */
 116         if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
 117                 goto no_match;
 118         }
 119
 120         if (key->exclusion && event->exclusion) {
 121                 size_t i;
 122
 123                 /* Check exclusion counts first. */
 124                 if (event->exclusion->count != key->exclusion->count) {
 125                         goto no_match;
 126                 }
 127
 128                 /* Compare names individually. */
 129                 for (i = 0; i < event->exclusion->count; ++i) {
 130                         size_t j;
 131                         bool found = false;
 132                         const char *name_ev =
 133                                 LTTNG_EVENT_EXCLUSION_NAME_AT(
 134                                         event->exclusion, i);
 135
 136                         /*
 137                          * Compare this exclusion name to all the key's
 138                          * exclusion names.
 139                          */
 140                         for (j = 0; j < key->exclusion->count; ++j) {
 141                                 const char *name_key =
 142                                         LTTNG_EVENT_EXCLUSION_NAME_AT(
 143                                                 key->exclusion, j);
 144
 145                                 if (!strncmp(name_ev, name_key,
 146                                                 LTTNG_SYMBOL_NAME_LEN)) {
 147                                         /* Names match! */
 148                                         found = true;
 149                                         break;
 150                                 }
 151                         }
 152
 153                         /*
 154                          * If the current exclusion name was not found amongst
 155                          * the key's exclusion names, then there's no match.
 156                          */
 157                         if (!found) {
 158                                 goto no_match;
 159                         }
 160                 }
 161         }
 162         /* Match. */
 163         return 1;
 164
 165 no_match:
 166         return 0;
 167 }
 168
 169 /*
 170  * Find the channel in the hashtable and return channel pointer. RCU read side
 171  * lock MUST be acquired before calling this.
 172  */
 173 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 174                 char *name)
 175 {
 176         struct lttng_ht_node_str *node;
 177         struct lttng_ht_iter iter;
 178
 179         /*
 180          * If we receive an empty string for channel name, it means the
 181          * default channel name is requested.
 182          */
 183         if (name[0] == '\0')
 184                 name = DEFAULT_CHANNEL_NAME;
 185
 186         lttng_ht_lookup(ht, (void *)name, &iter);
 187         node = lttng_ht_iter_get_node_str(&iter);
 188         if (node == NULL) {
 189                 goto error;
 190         }
 191
 192         DBG2("Trace UST channel %s found by name", name);
 193
 194         return caa_container_of(node, struct ltt_ust_channel, node);
 195
 196 error:
 197         DBG2("Trace UST channel %s not found by name", name);
 198         return NULL;
 199 }
 200
 201 /*
 202  * Find the event in the hashtable and return event pointer. RCU read side lock
 203  * MUST be acquired before calling this.
 204  */
 205 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 206                 char *name, struct lttng_filter_bytecode *filter,
 207                 enum lttng_ust_loglevel_type loglevel_type, int loglevel_value,
 208                 struct lttng_event_exclusion *exclusion)
 209 {
 210         struct lttng_ht_node_str *node;
 211         struct lttng_ht_iter iter;
 212         struct ltt_ust_ht_key key;
 213
 214         assert(name);
 215         assert(ht);
 216
 217         key.name = name;
 218         key.filter = filter;
 219         key.loglevel_type = loglevel_type;
 220         key.loglevel_value = loglevel_value;
 221         key.exclusion = exclusion;
 222
 223         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 224                         trace_ust_ht_match_event, &key, &iter.iter);
 225         node = lttng_ht_iter_get_node_str(&iter);
 226         if (node == NULL) {
 227                 goto error;
 228         }
 229
 230         DBG2("Trace UST event %s found", key.name);
 231
 232         return caa_container_of(node, struct ltt_ust_event, node);
 233
 234 error:
 235         DBG2("Trace UST event %s NOT found", key.name);
 236         return NULL;
 237 }
 238
 239 /*
 240  * Lookup an agent in the session agents hash table by domain type and return
 241  * the object if found else NULL.
 242  *
 243  * RCU read side lock must be acquired before calling and only released
 244  * once the agent is no longer in scope or being used.
 245  */
 246 struct agent *trace_ust_find_agent(struct ltt_ust_session *session,
 247                 enum lttng_domain_type domain_type)
 248 {
 249         struct agent *agt = NULL;
 250         struct lttng_ht_node_u64 *node;
 251         struct lttng_ht_iter iter;
 252         uint64_t key;
 253
 254         assert(session);
 255
 256         DBG3("Trace ust agent lookup for domain %d", domain_type);
 257
 258         key = domain_type;
 259
 260         lttng_ht_lookup(session->agents, &key, &iter);
 261         node = lttng_ht_iter_get_node_u64(&iter);
 262         if (!node) {
 263                 goto end;
 264         }
 265         agt = caa_container_of(node, struct agent, node);
 266
 267 end:
 268         return agt;
 269 }
 270
 271 /*
 272  * Allocate and initialize a ust session data structure.
 273  *
 274  * Return pointer to structure or NULL.
 275  */
 276 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 277 {
 278         struct ltt_ust_session *lus;
 279
 280         /* Allocate a new ltt ust session */
 281         lus = zmalloc(sizeof(struct ltt_ust_session));
 282         if (lus == NULL) {
 283                 PERROR("create ust session zmalloc");
 284                 goto error_alloc;
 285         }
 286
 287         /* Init data structure */
 288         lus->id = session_id;
 289         lus->active = 0;
 290
 291         /* Set default metadata channel attribute. */
 292         lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 293         lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
 294         lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 295         lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 296         lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 297         lus->metadata_attr.output = LTTNG_UST_MMAP;
 298
 299         /*
 300          * Default buffer type. This can be changed through an enable channel
 301          * requesting a different type. Note that this can only be changed once
 302          * during the session lifetime which is at the first enable channel and
 303          * only before start. The flag buffer_type_changed indicates the status.
 304          */
 305         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 306         /* Once set to 1, the buffer_type is immutable for the session. */
 307         lus->buffer_type_changed = 0;
 308         /* Init it in case it get used after allocation. */
 309         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 310
 311         /* Alloc UST global domain channels' HT */
 312         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 313         /* Alloc agent hash table. */
 314         lus->agents = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 315
 316         lus->tracker_list_vpid = lttng_tracker_list_create();
 317         if (!lus->tracker_list_vpid) {
 318                 goto error;
 319         }
 320         lus->tracker_list_vuid = lttng_tracker_list_create();
 321         if (!lus->tracker_list_vuid) {
 322                 goto error;
 323         }
 324         lus->tracker_list_vgid = lttng_tracker_list_create();
 325         if (!lus->tracker_list_vgid) {
 326                 goto error;
 327         }
 328         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 329         if (lus->consumer == NULL) {
 330                 goto error;
 331         }
 332
 333         DBG2("UST trace session create successful");
 334
 335         return lus;
 336
 337 error:
 338         lttng_tracker_list_destroy(lus->tracker_list_vpid);
 339         lttng_tracker_list_destroy(lus->tracker_list_vuid);
 340         lttng_tracker_list_destroy(lus->tracker_list_vgid);
 341         ht_cleanup_push(lus->domain_global.channels);
 342         ht_cleanup_push(lus->agents);
 343         free(lus);
 344 error_alloc:
 345         return NULL;
 346 }
 347
 348 /*
 349  * Allocate and initialize a ust channel data structure.
 350  *
 351  * Return pointer to structure or NULL.
 352  */
 353 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 354                 enum lttng_domain_type domain)
 355 {
 356         struct ltt_ust_channel *luc;
 357
 358         assert(chan);
 359
 360         luc = zmalloc(sizeof(struct ltt_ust_channel));
 361         if (luc == NULL) {
 362                 PERROR("ltt_ust_channel zmalloc");
 363                 goto error;
 364         }
 365
 366         luc->domain = domain;
 367
 368         /* Copy UST channel attributes */
 369         luc->attr.overwrite = chan->attr.overwrite;
 370         luc->attr.subbuf_size = chan->attr.subbuf_size;
 371         luc->attr.num_subbuf = chan->attr.num_subbuf;
 372         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 373         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 374         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 375
 376         /* Translate to UST output enum */
 377         switch (luc->attr.output) {
 378         default:
 379                 luc->attr.output = LTTNG_UST_MMAP;
 380                 break;
 381         }
 382
 383         /*
 384          * If we receive an empty string for channel name, it means the
 385          * default channel name is requested.
 386          */
 387         if (chan->name[0] == '\0') {
 388                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 389         } else {
 390                 /* Copy channel name */
 391                 strncpy(luc->name, chan->name, sizeof(luc->name));
 392         }
 393         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 394
 395         /* Init node */
 396         lttng_ht_node_init_str(&luc->node, luc->name);
 397         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 398
 399         /* Alloc hash tables */
 400         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 401         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 402
 403         /* On-disk circular buffer parameters */
 404         luc->tracefile_size = chan->attr.tracefile_size;
 405         luc->tracefile_count = chan->attr.tracefile_count;
 406
 407         DBG2("Trace UST channel %s created", luc->name);
 408
 409 error:
 410         return luc;
 411 }
 412
 413 /*
 414  * Validates an exclusion list.
 415  *
 416  * Returns 0 if valid, negative value if invalid.
 417  */
 418 static int validate_exclusion(struct lttng_event_exclusion *exclusion)
 419 {
 420         size_t i;
 421         int ret = 0;
 422
 423         assert(exclusion);
 424
 425         for (i = 0; i < exclusion->count; ++i) {
 426                 size_t j;
 427                 const char *name_a =
 428                         LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
 429
 430                 for (j = 0; j < i; ++j) {
 431                         const char *name_b =
 432                                 LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, j);
 433
 434                         if (!strncmp(name_a, name_b, LTTNG_SYMBOL_NAME_LEN)) {
 435                                 /* Match! */
 436                                 ret = -1;
 437                                 goto end;
 438                         }
 439                 }
 440         }
 441
 442 end:
 443         return ret;
 444 }
 445
 446 /*
 447  * Allocate and initialize a ust event. Set name and event type.
 448  * We own filter_expression, filter, and exclusion.
 449  *
 450  * Return pointer to structure or NULL.
 451  */
 452 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 453                 char *filter_expression,
 454                 struct lttng_filter_bytecode *filter,
 455                 struct lttng_event_exclusion *exclusion,
 456                 bool internal_event)
 457 {
 458         struct ltt_ust_event *lue;
 459
 460         assert(ev);
 461
 462         if (exclusion && validate_exclusion(exclusion)) {
 463                 goto error;
 464         }
 465
 466         lue = zmalloc(sizeof(struct ltt_ust_event));
 467         if (lue == NULL) {
 468                 PERROR("ust event zmalloc");
 469                 goto error;
 470         }
 471
 472         lue->internal = internal_event;
 473
 474         switch (ev->type) {
 475         case LTTNG_EVENT_PROBE:
 476                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 477                 break;
 478         case LTTNG_EVENT_FUNCTION:
 479                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 480                 break;
 481         case LTTNG_EVENT_FUNCTION_ENTRY:
 482                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 483                 break;
 484         case LTTNG_EVENT_TRACEPOINT:
 485                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 486                 break;
 487         default:
 488                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 489                 goto error_free_event;
 490         }
 491
 492         /* Copy event name */
 493         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 494         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 495
 496         switch (ev->loglevel_type) {
 497         case LTTNG_EVENT_LOGLEVEL_ALL:
 498                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 499                 lue->attr.loglevel = -1;        /* Force to -1 */
 500                 break;
 501         case LTTNG_EVENT_LOGLEVEL_RANGE:
 502                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 503                 lue->attr.loglevel = ev->loglevel;
 504                 break;
 505         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 506                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 507                 lue->attr.loglevel = ev->loglevel;
 508                 break;
 509         default:
 510                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 511                 goto error_free_event;
 512         }
 513
 514         /* Same layout. */
 515         lue->filter_expression = filter_expression;
 516         lue->filter = filter;
 517         lue->exclusion = exclusion;
 518
 519         /* Init node */
 520         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 521
 522         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 523                 lue->attr.name, lue->attr.loglevel_type,
 524                 lue->attr.loglevel);
 525
 526         return lue;
 527
 528 error_free_event:
 529         free(lue);
 530 error:
 531         free(filter_expression);
 532         free(filter);
 533         free(exclusion);
 534         return NULL;
 535 }
 536
 537 static
 538 int trace_ust_context_type_event_to_ust(
 539                 enum lttng_event_context_type type)
 540 {
 541         int utype;
 542
 543         switch (type) {
 544         case LTTNG_EVENT_CONTEXT_VTID:
 545                 utype = LTTNG_UST_CONTEXT_VTID;
 546                 break;
 547         case LTTNG_EVENT_CONTEXT_VPID:
 548                 utype = LTTNG_UST_CONTEXT_VPID;
 549                 break;
 550         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 551                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 552                 break;
 553         case LTTNG_EVENT_CONTEXT_PROCNAME:
 554                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 555                 break;
 556         case LTTNG_EVENT_CONTEXT_IP:
 557                 utype = LTTNG_UST_CONTEXT_IP;
 558                 break;
 559         case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
 560                 if (!ustctl_has_perf_counters()) {
 561                         utype = -1;
 562                         WARN("Perf counters not implemented in UST");
 563                 } else {
 564                         utype = LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER;
 565                 }
 566                 break;
 567         case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
 568                 utype = LTTNG_UST_CONTEXT_APP_CONTEXT;
 569                 break;
 570         default:
 571                 utype = -1;
 572                 break;
 573         }
 574         return utype;
 575 }
 576
 577 /*
 578  * Return 1 if contexts match, 0 otherwise.
 579  */
 580 int trace_ust_match_context(struct ltt_ust_context *uctx,
 581                 struct lttng_event_context *ctx)
 582 {
 583         int utype;
 584
 585         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 586         if (utype < 0) {
 587                 return 0;
 588         }
 589         if (uctx->ctx.ctx != utype) {
 590                 return 0;
 591         }
 592         switch (utype) {
 593         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 594                 if (uctx->ctx.u.perf_counter.type
 595                                 != ctx->u.perf_counter.type) {
 596                         return 0;
 597                 }
 598                 if (uctx->ctx.u.perf_counter.config
 599                                 != ctx->u.perf_counter.config) {
 600                         return 0;
 601                 }
 602                 if (strncmp(uctx->ctx.u.perf_counter.name,
 603                                 ctx->u.perf_counter.name,
 604                                 LTTNG_UST_SYM_NAME_LEN)) {
 605                         return 0;
 606                 }
 607                 break;
 608         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 609                 assert(uctx->ctx.u.app_ctx.provider_name);
 610                 assert(uctx->ctx.u.app_ctx.ctx_name);
 611                 if (strcmp(uctx->ctx.u.app_ctx.provider_name,
 612                                 ctx->u.app_ctx.provider_name) ||
 613                                 strcmp(uctx->ctx.u.app_ctx.ctx_name,
 614                                 ctx->u.app_ctx.ctx_name)) {
 615                         return 0;
 616                 }
 617         default:
 618                 break;
 619
 620         }
 621         return 1;
 622 }
 623
 624 /*
 625  * Allocate and initialize an UST context.
 626  *
 627  * Return pointer to structure or NULL.
 628  */
 629 struct ltt_ust_context *trace_ust_create_context(
 630                 struct lttng_event_context *ctx)
 631 {
 632         struct ltt_ust_context *uctx = NULL;
 633         int utype;
 634
 635         assert(ctx);
 636
 637         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 638         if (utype < 0) {
 639                 ERR("Invalid UST context");
 640                 goto end;
 641         }
 642
 643         uctx = zmalloc(sizeof(struct ltt_ust_context));
 644         if (!uctx) {
 645                 PERROR("zmalloc ltt_ust_context");
 646                 goto end;
 647         }
 648
 649         uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
 650         switch (utype) {
 651         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 652                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 653                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 654                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 655                                 LTTNG_UST_SYM_NAME_LEN);
 656                 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 657                 break;
 658         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 659         {
 660                 char *provider_name = NULL, *ctx_name = NULL;
 661
 662                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 663                 if (!provider_name) {
 664                         goto error;
 665                 }
 666                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 667
 668                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 669                 if (!ctx_name) {
 670                         goto error;
 671                 }
 672                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 673                 break;
 674         }
 675         default:
 676                 break;
 677         }
 678         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 679 end:
 680         return uctx;
 681 error:
 682         trace_ust_destroy_context(uctx);
 683         return NULL;
 684 }
 685
 686 static
 687 void destroy_id_tracker_node_rcu(struct rcu_head *head)
 688 {
 689         struct ust_id_tracker_node *tracker_node =
 690                 caa_container_of(head, struct ust_id_tracker_node, node.head);
 691         free(tracker_node);
 692 }
 693
 694 static
 695 void destroy_id_tracker_node(struct ust_id_tracker_node *tracker_node)
 696 {
 697
 698         call_rcu(&tracker_node->node.head, destroy_id_tracker_node_rcu);
 699 }
 700
 701 static
 702 int init_id_tracker(struct ust_id_tracker *id_tracker)
 703 {
 704         int ret = LTTNG_OK;
 705
 706         id_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 707         if (!id_tracker->ht) {
 708                 ret = LTTNG_ERR_NOMEM;
 709                 goto end;
 710         }
 711
 712 end:
 713         return ret;
 714 }
 715
 716 /*
 717  * Teardown id tracker content, but don't free id_tracker object.
 718  */
 719 static
 720 void fini_id_tracker(struct ust_id_tracker *id_tracker)
 721 {
 722         struct ust_id_tracker_node *tracker_node;
 723         struct lttng_ht_iter iter;
 724
 725         if (!id_tracker->ht) {
 726                 return;
 727         }
 728         rcu_read_lock();
 729         cds_lfht_for_each_entry(id_tracker->ht->ht,
 730                         &iter.iter, tracker_node, node.node) {
 731                 int ret = lttng_ht_del(id_tracker->ht, &iter);
 732
 733                 assert(!ret);
 734                 destroy_id_tracker_node(tracker_node);
 735         }
 736         rcu_read_unlock();
 737         ht_cleanup_push(id_tracker->ht);
 738         id_tracker->ht = NULL;
 739 }
 740
 741 static
 742 struct ust_id_tracker_node *id_tracker_lookup(
 743                 struct ust_id_tracker *id_tracker, int id,
 744                 struct lttng_ht_iter *iter)
 745 {
 746         unsigned long _id = (unsigned long) id;
 747         struct lttng_ht_node_ulong *node;
 748
 749         lttng_ht_lookup(id_tracker->ht, (void *) _id, iter);
 750         node = lttng_ht_iter_get_node_ulong(iter);
 751         if (node) {
 752                 return caa_container_of(node, struct ust_id_tracker_node,
 753                         node);
 754         } else {
 755                 return NULL;
 756         }
 757 }
 758
 759 static
 760 int id_tracker_add_id(struct ust_id_tracker *id_tracker, int id)
 761 {
 762         int retval = LTTNG_OK;
 763         struct ust_id_tracker_node *tracker_node;
 764         struct lttng_ht_iter iter;
 765
 766         if (id < 0) {
 767                 retval = LTTNG_ERR_INVALID;
 768                 goto end;
 769         }
 770         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 771         if (tracker_node) {
 772                 /* Already exists. */
 773                 retval = LTTNG_ERR_ID_TRACKED;
 774                 goto end;
 775         }
 776         tracker_node = zmalloc(sizeof(*tracker_node));
 777         if (!tracker_node) {
 778                 retval = LTTNG_ERR_NOMEM;
 779                 goto end;
 780         }
 781         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) id);
 782         lttng_ht_add_unique_ulong(id_tracker->ht, &tracker_node->node);
 783 end:
 784         return retval;
 785 }
 786
 787 static
 788 int id_tracker_del_id(struct ust_id_tracker *id_tracker, int id)
 789 {
 790         int retval = LTTNG_OK, ret;
 791         struct ust_id_tracker_node *tracker_node;
 792         struct lttng_ht_iter iter;
 793
 794         if (id < 0) {
 795                 retval = LTTNG_ERR_INVALID;
 796                 goto end;
 797         }
 798         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 799         if (!tracker_node) {
 800                 /* Not found */
 801                 retval = LTTNG_ERR_ID_NOT_TRACKED;
 802                 goto end;
 803         }
 804         ret = lttng_ht_del(id_tracker->ht, &iter);
 805         assert(!ret);
 806
 807         destroy_id_tracker_node(tracker_node);
 808 end:
 809         return retval;
 810 }
 811
 812 static
 813 struct ust_id_tracker *get_id_tracker(struct ltt_ust_session *session,
 814                 enum lttng_tracker_type tracker_type)
 815 {
 816         switch (tracker_type) {
 817         case LTTNG_TRACKER_VPID:
 818                 return &session->vpid_tracker;
 819         case LTTNG_TRACKER_VUID:
 820                 return &session->vuid_tracker;
 821         case LTTNG_TRACKER_VGID:
 822                 return &session->vgid_tracker;
 823         default:
 824                 return NULL;
 825         }
 826 }
 827
 828 static
 829 struct lttng_tracker_list *get_id_tracker_list(struct ltt_ust_session *session,
 830                 enum lttng_tracker_type tracker_type)
 831 {
 832         switch (tracker_type) {
 833         case LTTNG_TRACKER_VPID:
 834                 return session->tracker_list_vpid;
 835         case LTTNG_TRACKER_VUID:
 836                 return session->tracker_list_vuid;
 837         case LTTNG_TRACKER_VGID:
 838                 return session->tracker_list_vgid;
 839         default:
 840                 return NULL;
 841         }
 842 }
 843
 844 /*
 845  * The session lock is held when calling this function.
 846  */
 847 int trace_ust_id_tracker_lookup(enum lttng_tracker_type tracker_type,
 848                 struct ltt_ust_session *session, int id)
 849 {
 850         struct lttng_ht_iter iter;
 851         struct ust_id_tracker *id_tracker;
 852
 853         id_tracker = get_id_tracker(session, tracker_type);
 854         if (!id_tracker) {
 855                 abort();
 856         }
 857         if (!id_tracker->ht) {
 858                 return 1;
 859         }
 860         if (id_tracker_lookup(id_tracker, id, &iter)) {
 861                 return 1;
 862         }
 863         return 0;
 864 }
 865
 866 /*
 867  * Called with the session lock held.
 868  */
 869 int trace_ust_track_id(enum lttng_tracker_type tracker_type,
 870                 struct ltt_ust_session *session,
 871                 struct lttng_tracker_id *id)
 872 {
 873         int retval = LTTNG_OK;
 874         struct ust_id_tracker *id_tracker;
 875         struct lttng_tracker_list *tracker_list;
 876         int value;
 877         struct lttng_tracker_id *saved_ids;
 878         ssize_t saved_ids_count, i;
 879
 880         if (tracker_type == LTTNG_TRACKER_PID) {
 881                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
 882                 tracker_type = LTTNG_TRACKER_VPID;
 883         }
 884
 885         retval = lttng_tracker_id_lookup_string(tracker_type,
 886                         id, &value);
 887         if (retval != LTTNG_OK) {
 888                 return retval;
 889         }
 890         tracker_list = get_id_tracker_list(session, tracker_type);
 891         if (!tracker_list) {
 892                 return LTTNG_ERR_INVALID;
 893         }
 894         /* Save list for restore on error. */
 895         saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
 896         if (saved_ids_count < 0) {
 897                 return LTTNG_ERR_INVALID;
 898         }
 899         /* Add to list. */
 900         retval = lttng_tracker_list_add(tracker_list, id);
 901         if (retval != LTTNG_OK) {
 902                 goto end;
 903         }
 904
 905         id_tracker = get_id_tracker(session, tracker_type);
 906         if (!id_tracker) {
 907                 abort();
 908         }
 909         if (value == -1) {
 910                 /* Track all ids: destroy tracker if exists. */
 911                 if (id_tracker->ht) {
 912                         fini_id_tracker(id_tracker);
 913                         /* Ensure all apps have session. */
 914                         ust_app_global_update_all(session);
 915                 }
 916         } else {
 917                 if (!id_tracker->ht) {
 918                         /* Create tracker. */
 919                         retval = init_id_tracker(id_tracker);
 920                         if (retval != LTTNG_OK) {
 921                                 ERR("Error initializing ID tracker");
 922                                 goto end_restore;
 923                         }
 924                         retval = id_tracker_add_id(id_tracker, value);
 925                         if (retval != LTTNG_OK) {
 926                                 fini_id_tracker(id_tracker);
 927                                 goto end_restore;
 928                         }
 929                         /* Keep only apps matching ID. */
 930                         ust_app_global_update_all(session);
 931                 } else {
 932                         struct ust_app *app;
 933
 934                         retval = id_tracker_add_id(id_tracker, value);
 935                         if (retval != LTTNG_OK) {
 936                                 goto end_restore;
 937                         }
 938                         /* Add session to application */
 939                         switch (tracker_type) {
 940                         case LTTNG_TRACKER_VPID:
 941                                 app = ust_app_find_by_pid(value);
 942                                 if (app) {
 943                                         ust_app_global_update(session, app);
 944                                 }
 945                                 break;
 946                         default:
 947                                 /* Keep only apps matching ID. */
 948                                 ust_app_global_update_all(session);
 949                         }
 950                 }
 951         }
 952         goto end;
 953
 954 end_restore:
 955         if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
 956                 ERR("Error on tracker add error handling.\n");
 957         }
 958 end:
 959         for (i = 0; i < saved_ids_count; i++) {
 960                 free(saved_ids[i].string);
 961         }
 962         free(saved_ids);
 963         return retval;
 964 }
 965
 966 /*
 967  * Called with the session lock held.
 968  */
 969 int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
 970                 struct ltt_ust_session *session, struct lttng_tracker_id *id)
 971 {
 972         int retval = LTTNG_OK;
 973         struct ust_id_tracker *id_tracker;
 974         struct lttng_tracker_list *tracker_list;
 975         int value;
 976         struct lttng_tracker_id *saved_ids;
 977         ssize_t saved_ids_count, i;
 978
 979         if (tracker_type == LTTNG_TRACKER_PID) {
 980                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
 981                 tracker_type = LTTNG_TRACKER_VPID;
 982         }
 983
 984         retval = lttng_tracker_id_lookup_string(tracker_type,
 985                         id, &value);
 986         if (retval != LTTNG_OK) {
 987                 return retval;
 988         }
 989
 990         tracker_list = get_id_tracker_list(session, tracker_type);
 991         if (!tracker_list) {
 992                 return LTTNG_ERR_INVALID;
 993         }
 994         /* Save list for restore on error. */
 995         saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
 996         if (saved_ids_count < 0) {
 997                 return LTTNG_ERR_INVALID;
 998         }
 999         /* Remove from list. */
1000         retval = lttng_tracker_list_remove(tracker_list, id);
1001         if (retval != LTTNG_OK) {
1002                 goto end;
1003         }
1004
1005         id_tracker = get_id_tracker(session, tracker_type);
1006         if (!id_tracker) {
1007                 abort();
1008         }
1009
1010         if (value == -1) {
1011                 /* Create empty tracker, replace old tracker. */
1012                 struct ust_id_tracker tmp_tracker;
1013
1014                 tmp_tracker = *id_tracker;
1015                 retval = init_id_tracker(id_tracker);
1016                 if (retval != LTTNG_OK) {
1017                         ERR("Error initializing ID tracker");
1018                         /* Rollback operation. */
1019                         *id_tracker = tmp_tracker;
1020                         goto end_restore;
1021                 }
1022                 fini_id_tracker(&tmp_tracker);
1023
1024                 /* Keep only apps matching ID. */
1025                 ust_app_global_update_all(session);
1026         } else {
1027                 struct ust_app *app;
1028
1029                 if (!id_tracker->ht) {
1030                         /* No ID being tracked. */
1031                         retval = LTTNG_ERR_ID_NOT_TRACKED;
1032                         goto end_restore;
1033                 }
1034                 /* Remove ID from tracker */
1035                 retval = id_tracker_del_id(id_tracker, value);
1036                 if (retval != LTTNG_OK) {
1037                         goto end_restore;
1038                 }
1039                 switch (tracker_type) {
1040                 case LTTNG_TRACKER_VPID:
1041                         /* Remove session from application. */
1042                         app = ust_app_find_by_pid(value);
1043                         if (app) {
1044                                 ust_app_global_update(session, app);
1045                         }
1046                         break;
1047                 default:
1048                         /* Keep only apps matching ID. */
1049                         ust_app_global_update_all(session);
1050                 }
1051         }
1052         goto end;
1053
1054 end_restore:
1055         if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
1056                 ERR("Error on tracker remove error handling.\n");
1057         }
1058 end:
1059         for (i = 0; i < saved_ids_count; i++) {
1060                 free(saved_ids[i].string);
1061         }
1062         free(saved_ids);
1063         return retval;
1064 }
1065
1066 /*
1067  * Called with session lock held.
1068  */
1069 ssize_t trace_ust_list_tracker_ids(enum lttng_tracker_type tracker_type,
1070                 struct ltt_ust_session *session,
1071                 struct lttng_tracker_id **_ids)
1072 {
1073         struct lttng_tracker_list *tracker_list;
1074
1075         if (tracker_type == LTTNG_TRACKER_PID) {
1076                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
1077                 tracker_type = LTTNG_TRACKER_VPID;
1078         }
1079
1080         tracker_list = get_id_tracker_list(session, tracker_type);
1081         if (!tracker_list) {
1082                 return -LTTNG_ERR_INVALID;
1083         }
1084         return lttng_tracker_id_get_list(tracker_list, _ids);
1085 }
1086
1087 /*
1088  * RCU safe free context structure.
1089  */
1090 static void destroy_context_rcu(struct rcu_head *head)
1091 {
1092         struct lttng_ht_node_ulong *node =
1093                 caa_container_of(head, struct lttng_ht_node_ulong, head);
1094         struct ltt_ust_context *ctx =
1095                 caa_container_of(node, struct ltt_ust_context, node);
1096
1097         trace_ust_destroy_context(ctx);
1098 }
1099
1100 /*
1101  * Cleanup UST context hash table.
1102  */
1103 static void destroy_contexts(struct lttng_ht *ht)
1104 {
1105         int ret;
1106         struct lttng_ht_node_ulong *node;
1107         struct lttng_ht_iter iter;
1108         struct ltt_ust_context *ctx;
1109
1110         assert(ht);
1111
1112         rcu_read_lock();
1113         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
1114                 /* Remove from ordered list. */
1115                 ctx = caa_container_of(node, struct ltt_ust_context, node);
1116                 cds_list_del(&ctx->list);
1117                 /* Remove from channel's hash table. */
1118                 ret = lttng_ht_del(ht, &iter);
1119                 if (!ret) {
1120                         call_rcu(&node->head, destroy_context_rcu);
1121                 }
1122         }
1123         rcu_read_unlock();
1124
1125         ht_cleanup_push(ht);
1126 }
1127
1128 /*
1129  * Cleanup ust event structure.
1130  */
1131 void trace_ust_destroy_event(struct ltt_ust_event *event)
1132 {
1133         assert(event);
1134
1135         DBG2("Trace destroy UST event %s", event->attr.name);
1136         free(event->filter_expression);
1137         free(event->filter);
1138         free(event->exclusion);
1139         free(event);
1140 }
1141
1142 /*
1143  * Cleanup ust context structure.
1144  */
1145 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1146 {
1147         assert(ctx);
1148
1149         if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1150                 free(ctx->ctx.u.app_ctx.provider_name);
1151                 free(ctx->ctx.u.app_ctx.ctx_name);
1152         }
1153         free(ctx);
1154 }
1155
1156 /*
1157  * URCU intermediate call to complete destroy event.
1158  */
1159 static void destroy_event_rcu(struct rcu_head *head)
1160 {
1161         struct lttng_ht_node_str *node =
1162                 caa_container_of(head, struct lttng_ht_node_str, head);
1163         struct ltt_ust_event *event =
1164                 caa_container_of(node, struct ltt_ust_event, node);
1165
1166         trace_ust_destroy_event(event);
1167 }
1168
1169 /*
1170  * Cleanup UST events hashtable.
1171  */
1172 static void destroy_events(struct lttng_ht *events)
1173 {
1174         int ret;
1175         struct lttng_ht_node_str *node;
1176         struct lttng_ht_iter iter;
1177
1178         assert(events);
1179
1180         rcu_read_lock();
1181         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1182                 ret = lttng_ht_del(events, &iter);
1183                 assert(!ret);
1184                 call_rcu(&node->head, destroy_event_rcu);
1185         }
1186         rcu_read_unlock();
1187
1188         ht_cleanup_push(events);
1189 }
1190
1191 /*
1192  * Cleanup ust channel structure.
1193  *
1194  * Should _NOT_ be called with RCU read lock held.
1195  */
1196 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1197 {
1198         assert(channel);
1199
1200         DBG2("Trace destroy UST channel %s", channel->name);
1201
1202         free(channel);
1203 }
1204
1205 /*
1206  * URCU intermediate call to complete destroy channel.
1207  */
1208 static void destroy_channel_rcu(struct rcu_head *head)
1209 {
1210         struct lttng_ht_node_str *node =
1211                 caa_container_of(head, struct lttng_ht_node_str, head);
1212         struct ltt_ust_channel *channel =
1213                 caa_container_of(node, struct ltt_ust_channel, node);
1214
1215         _trace_ust_destroy_channel(channel);
1216 }
1217
1218 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1219 {
1220         /* Destroying all events of the channel */
1221         destroy_events(channel->events);
1222         /* Destroying all context of the channel */
1223         destroy_contexts(channel->ctx);
1224
1225         call_rcu(&channel->node.head, destroy_channel_rcu);
1226 }
1227
1228 /*
1229  * Remove an UST channel from a channel HT.
1230  */
1231 void trace_ust_delete_channel(struct lttng_ht *ht,
1232                 struct ltt_ust_channel *channel)
1233 {
1234         int ret;
1235         struct lttng_ht_iter iter;
1236
1237         assert(ht);
1238         assert(channel);
1239
1240         iter.iter.node = &channel->node.node;
1241         ret = lttng_ht_del(ht, &iter);
1242         assert(!ret);
1243 }
1244
1245 /*
1246  * Iterate over a hash table containing channels and cleanup safely.
1247  */
1248 static void destroy_channels(struct lttng_ht *channels)
1249 {
1250         struct lttng_ht_node_str *node;
1251         struct lttng_ht_iter iter;
1252
1253         assert(channels);
1254
1255         rcu_read_lock();
1256         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1257                 struct ltt_ust_channel *chan =
1258                         caa_container_of(node, struct ltt_ust_channel, node);
1259
1260                 trace_ust_delete_channel(channels, chan);
1261                 trace_ust_destroy_channel(chan);
1262         }
1263         rcu_read_unlock();
1264
1265         ht_cleanup_push(channels);
1266 }
1267
1268 /*
1269  * Cleanup UST global domain.
1270  */
1271 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1272 {
1273         assert(dom);
1274
1275         destroy_channels(dom->channels);
1276 }
1277
1278 /*
1279  * Cleanup ust session structure
1280  *
1281  * Should *NOT* be called with RCU read-side lock held.
1282  */
1283 void trace_ust_destroy_session(struct ltt_ust_session *session)
1284 {
1285         struct agent *agt;
1286         struct buffer_reg_uid *reg, *sreg;
1287         struct lttng_ht_iter iter;
1288
1289         assert(session);
1290
1291         DBG2("Trace UST destroy session %" PRIu64, session->id);
1292
1293         /* Cleaning up UST domain */
1294         destroy_domain_global(&session->domain_global);
1295
1296         rcu_read_lock();
1297         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1298                 int ret = lttng_ht_del(session->agents, &iter);
1299
1300                 assert(!ret);
1301                 agent_destroy(agt);
1302         }
1303         rcu_read_unlock();
1304
1305         ht_cleanup_push(session->agents);
1306
1307         /* Cleanup UID buffer registry object(s). */
1308         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1309                         lnode) {
1310                 cds_list_del(&reg->lnode);
1311                 buffer_reg_uid_remove(reg);
1312                 buffer_reg_uid_destroy(reg, session->consumer);
1313         }
1314
1315         consumer_output_put(session->consumer);
1316
1317         lttng_tracker_list_destroy(session->tracker_list_vpid);
1318         lttng_tracker_list_destroy(session->tracker_list_vuid);
1319         lttng_tracker_list_destroy(session->tracker_list_vgid);
1320
1321         fini_id_tracker(&session->vpid_tracker);
1322         fini_id_tracker(&session->vuid_tracker);
1323         fini_id_tracker(&session->vgid_tracker);
1324
1325         free(session);
1326 }