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
  35 /*
  36  * Match function for the events hash table lookup.
  37  *
  38  * Matches by name only. Used by the disable command.
  39  */
  40 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  41                 const void *_key)
  42 {
  43         struct ltt_ust_event *event;
  44         const char *name;
  45
  46         assert(node);
  47         assert(_key);
  48
  49         event = caa_container_of(node, struct ltt_ust_event, node.node);
  50         name = _key;
  51
  52         /* Event name */
  53         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  54                 goto no_match;
  55         }
  56
  57         /* Match */
  58         return 1;
  59
  60 no_match:
  61         return 0;
  62 }
  63
  64 /*
  65  * Match function for the hash table lookup.
  66  *
  67  * It matches an ust event based on three attributes which are the event name,
  68  * the filter bytecode and the loglevel.
  69  */
  70 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  71 {
  72         struct ltt_ust_event *event;
  73         const struct ltt_ust_ht_key *key;
  74         int ev_loglevel_value;
  75         int ll_match;
  76
  77         assert(node);
  78         assert(_key);
  79
  80         event = caa_container_of(node, struct ltt_ust_event, node.node);
  81         key = _key;
  82         ev_loglevel_value = event->attr.loglevel;
  83
  84         /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
  85
  86         /* Event name */
  87         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  88                 goto no_match;
  89         }
  90
  91         /* Event loglevel value and type. */
  92         ll_match = loglevels_match(event->attr.loglevel_type,
  93                 ev_loglevel_value, key->loglevel_type,
  94                 key->loglevel_value, LTTNG_UST_LOGLEVEL_ALL);
  95
  96         if (!ll_match) {
  97                 goto no_match;
  98         }
  99
 100         /* Only one of the filters is NULL, fail. */
 101         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 102                 goto no_match;
 103         }
 104
 105         if (key->filter && event->filter) {
 106                 /* Both filters exists, check length followed by the bytecode. */
 107                 if (event->filter->len != key->filter->len ||
 108                                 memcmp(event->filter->data, key->filter->data,
 109                                         event->filter->len) != 0) {
 110                         goto no_match;
 111                 }
 112         }
 113
 114         /* If only one of the exclusions is NULL, fail. */
 115         if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
 116                 goto no_match;
 117         }
 118
 119         if (key->exclusion && event->exclusion) {
 120                 size_t i;
 121
 122                 /* Check exclusion counts first. */
 123                 if (event->exclusion->count != key->exclusion->count) {
 124                         goto no_match;
 125                 }
 126
 127                 /* Compare names individually. */
 128                 for (i = 0; i < event->exclusion->count; ++i) {
 129                         size_t j;
 130                         bool found = false;
 131                         const char *name_ev =
 132                                 LTTNG_EVENT_EXCLUSION_NAME_AT(
 133                                         event->exclusion, i);
 134
 135                         /*
 136                          * Compare this exclusion name to all the key's
 137                          * exclusion names.
 138                          */
 139                         for (j = 0; j < key->exclusion->count; ++j) {
 140                                 const char *name_key =
 141                                         LTTNG_EVENT_EXCLUSION_NAME_AT(
 142                                                 key->exclusion, j);
 143
 144                                 if (!strncmp(name_ev, name_key,
 145                                                 LTTNG_SYMBOL_NAME_LEN)) {
 146                                         /* Names match! */
 147                                         found = true;
 148                                         break;
 149                                 }
 150                         }
 151
 152                         /*
 153                          * If the current exclusion name was not found amongst
 154                          * the key's exclusion names, then there's no match.
 155                          */
 156                         if (!found) {
 157                                 goto no_match;
 158                         }
 159                 }
 160         }
 161         /* Match. */
 162         return 1;
 163
 164 no_match:
 165         return 0;
 166 }
 167
 168 /*
 169  * Find the channel in the hashtable and return channel pointer. RCU read side
 170  * lock MUST be acquired before calling this.
 171  */
 172 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 173                 char *name)
 174 {
 175         struct lttng_ht_node_str *node;
 176         struct lttng_ht_iter iter;
 177
 178         /*
 179          * If we receive an empty string for channel name, it means the
 180          * default channel name is requested.
 181          */
 182         if (name[0] == '\0')
 183                 name = DEFAULT_CHANNEL_NAME;
 184
 185         lttng_ht_lookup(ht, (void *)name, &iter);
 186         node = lttng_ht_iter_get_node_str(&iter);
 187         if (node == NULL) {
 188                 goto error;
 189         }
 190
 191         DBG2("Trace UST channel %s found by name", name);
 192
 193         return caa_container_of(node, struct ltt_ust_channel, node);
 194
 195 error:
 196         DBG2("Trace UST channel %s not found by name", name);
 197         return NULL;
 198 }
 199
 200 /*
 201  * Find the event in the hashtable and return event pointer. RCU read side lock
 202  * MUST be acquired before calling this.
 203  */
 204 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 205                 char *name, struct lttng_filter_bytecode *filter,
 206                 enum lttng_ust_loglevel_type loglevel_type, int loglevel_value,
 207                 struct lttng_event_exclusion *exclusion)
 208 {
 209         struct lttng_ht_node_str *node;
 210         struct lttng_ht_iter iter;
 211         struct ltt_ust_ht_key key;
 212
 213         assert(name);
 214         assert(ht);
 215
 216         key.name = name;
 217         key.filter = filter;
 218         key.loglevel_type = loglevel_type;
 219         key.loglevel_value = loglevel_value;
 220         key.exclusion = exclusion;
 221
 222         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 223                         trace_ust_ht_match_event, &key, &iter.iter);
 224         node = lttng_ht_iter_get_node_str(&iter);
 225         if (node == NULL) {
 226                 goto error;
 227         }
 228
 229         DBG2("Trace UST event %s found", key.name);
 230
 231         return caa_container_of(node, struct ltt_ust_event, node);
 232
 233 error:
 234         DBG2("Trace UST event %s NOT found", key.name);
 235         return NULL;
 236 }
 237
 238 /*
 239  * Lookup an agent in the session agents hash table by domain type and return
 240  * the object if found else NULL.
 241  *
 242  * RCU read side lock must be acquired before calling and only released
 243  * once the agent is no longer in scope or being used.
 244  */
 245 struct agent *trace_ust_find_agent(struct ltt_ust_session *session,
 246                 enum lttng_domain_type domain_type)
 247 {
 248         struct agent *agt = NULL;
 249         struct lttng_ht_node_u64 *node;
 250         struct lttng_ht_iter iter;
 251         uint64_t key;
 252
 253         assert(session);
 254
 255         DBG3("Trace ust agent lookup for domain %d", domain_type);
 256
 257         key = domain_type;
 258
 259         lttng_ht_lookup(session->agents, &key, &iter);
 260         node = lttng_ht_iter_get_node_u64(&iter);
 261         if (!node) {
 262                 goto end;
 263         }
 264         agt = caa_container_of(node, struct agent, node);
 265
 266 end:
 267         return agt;
 268 }
 269
 270 /*
 271  * Allocate and initialize a ust session data structure.
 272  *
 273  * Return pointer to structure or NULL.
 274  */
 275 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 276 {
 277         struct ltt_ust_session *lus;
 278
 279         /* Allocate a new ltt ust session */
 280         lus = zmalloc(sizeof(struct ltt_ust_session));
 281         if (lus == NULL) {
 282                 PERROR("create ust session zmalloc");
 283                 goto error_alloc;
 284         }
 285
 286         /* Init data structure */
 287         lus->id = session_id;
 288         lus->active = 0;
 289
 290         /* Set default metadata channel attribute. */
 291         lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 292         lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
 293         lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 294         lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 295         lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 296         lus->metadata_attr.output = LTTNG_UST_MMAP;
 297
 298         /*
 299          * Default buffer type. This can be changed through an enable channel
 300          * requesting a different type. Note that this can only be changed once
 301          * during the session lifetime which is at the first enable channel and
 302          * only before start. The flag buffer_type_changed indicates the status.
 303          */
 304         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 305         /* Once set to 1, the buffer_type is immutable for the session. */
 306         lus->buffer_type_changed = 0;
 307         /* Init it in case it get used after allocation. */
 308         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 309
 310         /* Alloc UST global domain channels' HT */
 311         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 312         /* Alloc agent hash table. */
 313         lus->agents = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 314
 315         lus->tracker_list_vpid = lttng_tracker_list_create();
 316         if (!lus->tracker_list_vpid) {
 317                 goto error;
 318         }
 319         lus->tracker_list_vuid = lttng_tracker_list_create();
 320         if (!lus->tracker_list_vuid) {
 321                 goto error;
 322         }
 323         lus->tracker_list_vgid = lttng_tracker_list_create();
 324         if (!lus->tracker_list_vgid) {
 325                 goto error;
 326         }
 327         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 328         if (lus->consumer == NULL) {
 329                 goto error;
 330         }
 331
 332         DBG2("UST trace session create successful");
 333
 334         return lus;
 335
 336 error:
 337         lttng_tracker_list_destroy(lus->tracker_list_vpid);
 338         lttng_tracker_list_destroy(lus->tracker_list_vuid);
 339         lttng_tracker_list_destroy(lus->tracker_list_vgid);
 340         ht_cleanup_push(lus->domain_global.channels);
 341         ht_cleanup_push(lus->agents);
 342         free(lus);
 343 error_alloc:
 344         return NULL;
 345 }
 346
 347 /*
 348  * Allocate and initialize a ust channel data structure.
 349  *
 350  * Return pointer to structure or NULL.
 351  */
 352 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 353                 enum lttng_domain_type domain)
 354 {
 355         struct ltt_ust_channel *luc;
 356
 357         assert(chan);
 358
 359         luc = zmalloc(sizeof(struct ltt_ust_channel));
 360         if (luc == NULL) {
 361                 PERROR("ltt_ust_channel zmalloc");
 362                 goto error;
 363         }
 364
 365         luc->domain = domain;
 366
 367         /* Copy UST channel attributes */
 368         luc->attr.overwrite = chan->attr.overwrite;
 369         luc->attr.subbuf_size = chan->attr.subbuf_size;
 370         luc->attr.num_subbuf = chan->attr.num_subbuf;
 371         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 372         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 373         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 374         luc->monitor_timer_interval = ((struct lttng_channel_extended *)
 375                         chan->attr.extended.ptr)->monitor_timer_interval;
 376         luc->attr.u.s.blocking_timeout = ((struct lttng_channel_extended *)
 377                         chan->attr.extended.ptr)->blocking_timeout;
 378
 379         /* Translate to UST output enum */
 380         switch (luc->attr.output) {
 381         default:
 382                 luc->attr.output = LTTNG_UST_MMAP;
 383                 break;
 384         }
 385
 386         /*
 387          * If we receive an empty string for channel name, it means the
 388          * default channel name is requested.
 389          */
 390         if (chan->name[0] == '\0') {
 391                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 392         } else {
 393                 /* Copy channel name */
 394                 strncpy(luc->name, chan->name, sizeof(luc->name));
 395         }
 396         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 397
 398         /* Init node */
 399         lttng_ht_node_init_str(&luc->node, luc->name);
 400         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 401
 402         /* Alloc hash tables */
 403         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 404         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 405
 406         /* On-disk circular buffer parameters */
 407         luc->tracefile_size = chan->attr.tracefile_size;
 408         luc->tracefile_count = chan->attr.tracefile_count;
 409
 410         DBG2("Trace UST channel %s created", luc->name);
 411
 412 error:
 413         return luc;
 414 }
 415
 416 /*
 417  * Validates an exclusion list.
 418  *
 419  * Returns 0 if valid, negative value if invalid.
 420  */
 421 static int validate_exclusion(struct lttng_event_exclusion *exclusion)
 422 {
 423         size_t i;
 424         int ret = 0;
 425
 426         assert(exclusion);
 427
 428         for (i = 0; i < exclusion->count; ++i) {
 429                 size_t j;
 430                 const char *name_a =
 431                         LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
 432
 433                 for (j = 0; j < i; ++j) {
 434                         const char *name_b =
 435                                 LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, j);
 436
 437                         if (!strncmp(name_a, name_b, LTTNG_SYMBOL_NAME_LEN)) {
 438                                 /* Match! */
 439                                 ret = -1;
 440                                 goto end;
 441                         }
 442                 }
 443         }
 444
 445 end:
 446         return ret;
 447 }
 448
 449 /*
 450  * Allocate and initialize a ust event. Set name and event type.
 451  * We own filter_expression, filter, and exclusion.
 452  *
 453  * Return pointer to structure or NULL.
 454  */
 455 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 456                 char *filter_expression,
 457                 struct lttng_filter_bytecode *filter,
 458                 struct lttng_event_exclusion *exclusion,
 459                 bool internal_event)
 460 {
 461         struct ltt_ust_event *lue;
 462
 463         assert(ev);
 464
 465         if (exclusion && validate_exclusion(exclusion)) {
 466                 goto error;
 467         }
 468
 469         lue = zmalloc(sizeof(struct ltt_ust_event));
 470         if (lue == NULL) {
 471                 PERROR("ust event zmalloc");
 472                 goto error;
 473         }
 474
 475         lue->internal = internal_event;
 476
 477         switch (ev->type) {
 478         case LTTNG_EVENT_PROBE:
 479                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 480                 break;
 481         case LTTNG_EVENT_FUNCTION:
 482                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 483                 break;
 484         case LTTNG_EVENT_FUNCTION_ENTRY:
 485                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 486                 break;
 487         case LTTNG_EVENT_TRACEPOINT:
 488                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 489                 break;
 490         default:
 491                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 492                 goto error_free_event;
 493         }
 494
 495         /* Copy event name */
 496         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 497         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 498
 499         switch (ev->loglevel_type) {
 500         case LTTNG_EVENT_LOGLEVEL_ALL:
 501                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 502                 lue->attr.loglevel = -1;        /* Force to -1 */
 503                 break;
 504         case LTTNG_EVENT_LOGLEVEL_RANGE:
 505                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 506                 lue->attr.loglevel = ev->loglevel;
 507                 break;
 508         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 509                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 510                 lue->attr.loglevel = ev->loglevel;
 511                 break;
 512         default:
 513                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 514                 goto error_free_event;
 515         }
 516
 517         /* Same layout. */
 518         lue->filter_expression = filter_expression;
 519         lue->filter = filter;
 520         lue->exclusion = exclusion;
 521
 522         /* Init node */
 523         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 524
 525         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 526                 lue->attr.name, lue->attr.loglevel_type,
 527                 lue->attr.loglevel);
 528
 529         return lue;
 530
 531 error_free_event:
 532         free(lue);
 533 error:
 534         free(filter_expression);
 535         free(filter);
 536         free(exclusion);
 537         return NULL;
 538 }
 539
 540 static
 541 int trace_ust_context_type_event_to_ust(
 542                 enum lttng_event_context_type type)
 543 {
 544         int utype;
 545
 546         switch (type) {
 547         case LTTNG_EVENT_CONTEXT_VTID:
 548                 utype = LTTNG_UST_CONTEXT_VTID;
 549                 break;
 550         case LTTNG_EVENT_CONTEXT_VPID:
 551                 utype = LTTNG_UST_CONTEXT_VPID;
 552                 break;
 553         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 554                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 555                 break;
 556         case LTTNG_EVENT_CONTEXT_PROCNAME:
 557                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 558                 break;
 559         case LTTNG_EVENT_CONTEXT_IP:
 560                 utype = LTTNG_UST_CONTEXT_IP;
 561                 break;
 562         case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
 563                 if (!ustctl_has_perf_counters()) {
 564                         utype = -1;
 565                         WARN("Perf counters not implemented in UST");
 566                 } else {
 567                         utype = LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER;
 568                 }
 569                 break;
 570         case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
 571                 utype = LTTNG_UST_CONTEXT_APP_CONTEXT;
 572                 break;
 573         default:
 574                 utype = -1;
 575                 break;
 576         }
 577         return utype;
 578 }
 579
 580 /*
 581  * Return 1 if contexts match, 0 otherwise.
 582  */
 583 int trace_ust_match_context(struct ltt_ust_context *uctx,
 584                 struct lttng_event_context *ctx)
 585 {
 586         int utype;
 587
 588         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 589         if (utype < 0) {
 590                 return 0;
 591         }
 592         if (uctx->ctx.ctx != utype) {
 593                 return 0;
 594         }
 595         switch (utype) {
 596         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 597                 if (uctx->ctx.u.perf_counter.type
 598                                 != ctx->u.perf_counter.type) {
 599                         return 0;
 600                 }
 601                 if (uctx->ctx.u.perf_counter.config
 602                                 != ctx->u.perf_counter.config) {
 603                         return 0;
 604                 }
 605                 if (strncmp(uctx->ctx.u.perf_counter.name,
 606                                 ctx->u.perf_counter.name,
 607                                 LTTNG_UST_SYM_NAME_LEN)) {
 608                         return 0;
 609                 }
 610                 break;
 611         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 612                 assert(uctx->ctx.u.app_ctx.provider_name);
 613                 assert(uctx->ctx.u.app_ctx.ctx_name);
 614                 if (strcmp(uctx->ctx.u.app_ctx.provider_name,
 615                                 ctx->u.app_ctx.provider_name) ||
 616                                 strcmp(uctx->ctx.u.app_ctx.ctx_name,
 617                                 ctx->u.app_ctx.ctx_name)) {
 618                         return 0;
 619                 }
 620         default:
 621                 break;
 622
 623         }
 624         return 1;
 625 }
 626
 627 /*
 628  * Allocate and initialize an UST context.
 629  *
 630  * Return pointer to structure or NULL.
 631  */
 632 struct ltt_ust_context *trace_ust_create_context(
 633                 struct lttng_event_context *ctx)
 634 {
 635         struct ltt_ust_context *uctx = NULL;
 636         int utype;
 637
 638         assert(ctx);
 639
 640         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 641         if (utype < 0) {
 642                 ERR("Invalid UST context");
 643                 goto end;
 644         }
 645
 646         uctx = zmalloc(sizeof(struct ltt_ust_context));
 647         if (!uctx) {
 648                 PERROR("zmalloc ltt_ust_context");
 649                 goto end;
 650         }
 651
 652         uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
 653         switch (utype) {
 654         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 655                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 656                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 657                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 658                                 LTTNG_UST_SYM_NAME_LEN);
 659                 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 660                 break;
 661         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 662         {
 663                 char *provider_name = NULL, *ctx_name = NULL;
 664
 665                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 666                 if (!provider_name) {
 667                         goto error;
 668                 }
 669                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 670
 671                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 672                 if (!ctx_name) {
 673                         goto error;
 674                 }
 675                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 676                 break;
 677         }
 678         default:
 679                 break;
 680         }
 681         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 682 end:
 683         return uctx;
 684 error:
 685         trace_ust_destroy_context(uctx);
 686         return NULL;
 687 }
 688
 689 static
 690 void destroy_id_tracker_node_rcu(struct rcu_head *head)
 691 {
 692         struct ust_id_tracker_node *tracker_node =
 693                 caa_container_of(head, struct ust_id_tracker_node, node.head);
 694         free(tracker_node);
 695 }
 696
 697 static
 698 void destroy_id_tracker_node(struct ust_id_tracker_node *tracker_node)
 699 {
 700
 701         call_rcu(&tracker_node->node.head, destroy_id_tracker_node_rcu);
 702 }
 703
 704 static
 705 int init_id_tracker(struct ust_id_tracker *id_tracker)
 706 {
 707         int ret = LTTNG_OK;
 708
 709         id_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 710         if (!id_tracker->ht) {
 711                 ret = LTTNG_ERR_NOMEM;
 712                 goto end;
 713         }
 714
 715 end:
 716         return ret;
 717 }
 718
 719 /*
 720  * Teardown id tracker content, but don't free id_tracker object.
 721  */
 722 static
 723 void fini_id_tracker(struct ust_id_tracker *id_tracker)
 724 {
 725         struct ust_id_tracker_node *tracker_node;
 726         struct lttng_ht_iter iter;
 727
 728         if (!id_tracker->ht) {
 729                 return;
 730         }
 731         rcu_read_lock();
 732         cds_lfht_for_each_entry(id_tracker->ht->ht,
 733                         &iter.iter, tracker_node, node.node) {
 734                 int ret = lttng_ht_del(id_tracker->ht, &iter);
 735
 736                 assert(!ret);
 737                 destroy_id_tracker_node(tracker_node);
 738         }
 739         rcu_read_unlock();
 740         ht_cleanup_push(id_tracker->ht);
 741         id_tracker->ht = NULL;
 742 }
 743
 744 static
 745 struct ust_id_tracker_node *id_tracker_lookup(
 746                 struct ust_id_tracker *id_tracker, int id,
 747                 struct lttng_ht_iter *iter)
 748 {
 749         unsigned long _id = (unsigned long) id;
 750         struct lttng_ht_node_ulong *node;
 751
 752         lttng_ht_lookup(id_tracker->ht, (void *) _id, iter);
 753         node = lttng_ht_iter_get_node_ulong(iter);
 754         if (node) {
 755                 return caa_container_of(node, struct ust_id_tracker_node,
 756                         node);
 757         } else {
 758                 return NULL;
 759         }
 760 }
 761
 762 static
 763 int id_tracker_add_id(struct ust_id_tracker *id_tracker, int id)
 764 {
 765         int retval = LTTNG_OK;
 766         struct ust_id_tracker_node *tracker_node;
 767         struct lttng_ht_iter iter;
 768
 769         if (id < 0) {
 770                 retval = LTTNG_ERR_INVALID;
 771                 goto end;
 772         }
 773         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 774         if (tracker_node) {
 775                 /* Already exists. */
 776                 retval = LTTNG_ERR_ID_TRACKED;
 777                 goto end;
 778         }
 779         tracker_node = zmalloc(sizeof(*tracker_node));
 780         if (!tracker_node) {
 781                 retval = LTTNG_ERR_NOMEM;
 782                 goto end;
 783         }
 784         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) id);
 785         lttng_ht_add_unique_ulong(id_tracker->ht, &tracker_node->node);
 786 end:
 787         return retval;
 788 }
 789
 790 static
 791 int id_tracker_del_id(struct ust_id_tracker *id_tracker, int id)
 792 {
 793         int retval = LTTNG_OK, ret;
 794         struct ust_id_tracker_node *tracker_node;
 795         struct lttng_ht_iter iter;
 796
 797         if (id < 0) {
 798                 retval = LTTNG_ERR_INVALID;
 799                 goto end;
 800         }
 801         tracker_node = id_tracker_lookup(id_tracker, id, &iter);
 802         if (!tracker_node) {
 803                 /* Not found */
 804                 retval = LTTNG_ERR_ID_NOT_TRACKED;
 805                 goto end;
 806         }
 807         ret = lttng_ht_del(id_tracker->ht, &iter);
 808         assert(!ret);
 809
 810         destroy_id_tracker_node(tracker_node);
 811 end:
 812         return retval;
 813 }
 814
 815 static
 816 struct ust_id_tracker *get_id_tracker(struct ltt_ust_session *session,
 817                 enum lttng_tracker_type tracker_type)
 818 {
 819         switch (tracker_type) {
 820         case LTTNG_TRACKER_VPID:
 821                 return &session->vpid_tracker;
 822         case LTTNG_TRACKER_VUID:
 823                 return &session->vuid_tracker;
 824         case LTTNG_TRACKER_VGID:
 825                 return &session->vgid_tracker;
 826         default:
 827                 return NULL;
 828         }
 829 }
 830
 831 static
 832 struct lttng_tracker_list *get_id_tracker_list(struct ltt_ust_session *session,
 833                 enum lttng_tracker_type tracker_type)
 834 {
 835         switch (tracker_type) {
 836         case LTTNG_TRACKER_VPID:
 837                 return session->tracker_list_vpid;
 838         case LTTNG_TRACKER_VUID:
 839                 return session->tracker_list_vuid;
 840         case LTTNG_TRACKER_VGID:
 841                 return session->tracker_list_vgid;
 842         default:
 843                 return NULL;
 844         }
 845 }
 846
 847 /*
 848  * The session lock is held when calling this function.
 849  */
 850 int trace_ust_id_tracker_lookup(enum lttng_tracker_type tracker_type,
 851                 struct ltt_ust_session *session, int id)
 852 {
 853         struct lttng_ht_iter iter;
 854         struct ust_id_tracker *id_tracker;
 855
 856         id_tracker = get_id_tracker(session, tracker_type);
 857         if (!id_tracker) {
 858                 abort();
 859         }
 860         if (!id_tracker->ht) {
 861                 return 1;
 862         }
 863         if (id_tracker_lookup(id_tracker, id, &iter)) {
 864                 return 1;
 865         }
 866         return 0;
 867 }
 868
 869 /*
 870  * Called with the session lock held.
 871  */
 872 int trace_ust_track_id(enum lttng_tracker_type tracker_type,
 873                 struct ltt_ust_session *session,
 874                 struct lttng_tracker_id *id)
 875 {
 876         int retval = LTTNG_OK;
 877         struct ust_id_tracker *id_tracker;
 878         struct lttng_tracker_list *tracker_list;
 879         int value;
 880         struct lttng_tracker_id *saved_ids;
 881         ssize_t saved_ids_count, i;
 882
 883         if (tracker_type == LTTNG_TRACKER_PID) {
 884                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
 885                 tracker_type = LTTNG_TRACKER_VPID;
 886         }
 887
 888         retval = lttng_tracker_id_lookup_string(tracker_type,
 889                         id, &value);
 890         if (retval != LTTNG_OK) {
 891                 return retval;
 892         }
 893         tracker_list = get_id_tracker_list(session, tracker_type);
 894         if (!tracker_list) {
 895                 return LTTNG_ERR_INVALID;
 896         }
 897         /* Save list for restore on error. */
 898         saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
 899         if (saved_ids_count < 0) {
 900                 return LTTNG_ERR_INVALID;
 901         }
 902         /* Add to list. */
 903         retval = lttng_tracker_list_add(tracker_list, id);
 904         if (retval != LTTNG_OK) {
 905                 goto end;
 906         }
 907
 908         id_tracker = get_id_tracker(session, tracker_type);
 909         if (!id_tracker) {
 910                 abort();
 911         }
 912         if (value == -1) {
 913                 /* Track all ids: destroy tracker if exists. */
 914                 if (id_tracker->ht) {
 915                         fini_id_tracker(id_tracker);
 916                         /* Ensure all apps have session. */
 917                         ust_app_global_update_all(session);
 918                 }
 919         } else {
 920                 if (!id_tracker->ht) {
 921                         /* Create tracker. */
 922                         retval = init_id_tracker(id_tracker);
 923                         if (retval != LTTNG_OK) {
 924                                 ERR("Error initializing ID tracker");
 925                                 goto end_restore;
 926                         }
 927                         retval = id_tracker_add_id(id_tracker, value);
 928                         if (retval != LTTNG_OK) {
 929                                 fini_id_tracker(id_tracker);
 930                                 goto end_restore;
 931                         }
 932                         /* Keep only apps matching ID. */
 933                         ust_app_global_update_all(session);
 934                 } else {
 935                         struct ust_app *app;
 936
 937                         retval = id_tracker_add_id(id_tracker, value);
 938                         if (retval != LTTNG_OK) {
 939                                 goto end_restore;
 940                         }
 941                         /* Add session to application */
 942                         switch (tracker_type) {
 943                         case LTTNG_TRACKER_VPID:
 944                                 app = ust_app_find_by_pid(value);
 945                                 if (app) {
 946                                         ust_app_global_update(session, app);
 947                                 }
 948                                 break;
 949                         default:
 950                                 /* Keep only apps matching ID. */
 951                                 ust_app_global_update_all(session);
 952                         }
 953                 }
 954         }
 955         goto end;
 956
 957 end_restore:
 958         if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
 959                 ERR("Error on tracker add error handling.\n");
 960         }
 961 end:
 962         for (i = 0; i < saved_ids_count; i++) {
 963                 free(saved_ids[i].string);
 964         }
 965         free(saved_ids);
 966         return retval;
 967 }
 968
 969 /*
 970  * Called with the session lock held.
 971  */
 972 int trace_ust_untrack_id(enum lttng_tracker_type tracker_type,
 973                 struct ltt_ust_session *session, struct lttng_tracker_id *id)
 974 {
 975         int retval = LTTNG_OK;
 976         struct ust_id_tracker *id_tracker;
 977         struct lttng_tracker_list *tracker_list;
 978         int value;
 979         struct lttng_tracker_id *saved_ids;
 980         ssize_t saved_ids_count, i;
 981
 982         if (tracker_type == LTTNG_TRACKER_PID) {
 983                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
 984                 tracker_type = LTTNG_TRACKER_VPID;
 985         }
 986
 987         retval = lttng_tracker_id_lookup_string(tracker_type,
 988                         id, &value);
 989         if (retval != LTTNG_OK) {
 990                 return retval;
 991         }
 992
 993         tracker_list = get_id_tracker_list(session, tracker_type);
 994         if (!tracker_list) {
 995                 return LTTNG_ERR_INVALID;
 996         }
 997         /* Save list for restore on error. */
 998         saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
 999         if (saved_ids_count < 0) {
1000                 return LTTNG_ERR_INVALID;
1001         }
1002         /* Remove from list. */
1003         retval = lttng_tracker_list_remove(tracker_list, id);
1004         if (retval != LTTNG_OK) {
1005                 goto end;
1006         }
1007
1008         id_tracker = get_id_tracker(session, tracker_type);
1009         if (!id_tracker) {
1010                 abort();
1011         }
1012
1013         if (value == -1) {
1014                 /* Create empty tracker, replace old tracker. */
1015                 struct ust_id_tracker tmp_tracker;
1016
1017                 tmp_tracker = *id_tracker;
1018                 retval = init_id_tracker(id_tracker);
1019                 if (retval != LTTNG_OK) {
1020                         ERR("Error initializing ID tracker");
1021                         /* Rollback operation. */
1022                         *id_tracker = tmp_tracker;
1023                         goto end_restore;
1024                 }
1025                 fini_id_tracker(&tmp_tracker);
1026
1027                 /* Keep only apps matching ID. */
1028                 ust_app_global_update_all(session);
1029         } else {
1030                 struct ust_app *app;
1031
1032                 if (!id_tracker->ht) {
1033                         /* No ID being tracked. */
1034                         retval = LTTNG_ERR_ID_NOT_TRACKED;
1035                         goto end_restore;
1036                 }
1037                 /* Remove ID from tracker */
1038                 retval = id_tracker_del_id(id_tracker, value);
1039                 if (retval != LTTNG_OK) {
1040                         goto end_restore;
1041                 }
1042                 switch (tracker_type) {
1043                 case LTTNG_TRACKER_VPID:
1044                         /* Remove session from application. */
1045                         app = ust_app_find_by_pid(value);
1046                         if (app) {
1047                                 ust_app_global_update(session, app);
1048                         }
1049                         break;
1050                 default:
1051                         /* Keep only apps matching ID. */
1052                         ust_app_global_update_all(session);
1053                 }
1054         }
1055         goto end;
1056
1057 end_restore:
1058         if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
1059                 ERR("Error on tracker remove error handling.\n");
1060         }
1061 end:
1062         for (i = 0; i < saved_ids_count; i++) {
1063                 free(saved_ids[i].string);
1064         }
1065         free(saved_ids);
1066         return retval;
1067 }
1068
1069 /*
1070  * Called with session lock held.
1071  */
1072 ssize_t trace_ust_list_tracker_ids(enum lttng_tracker_type tracker_type,
1073                 struct ltt_ust_session *session,
1074                 struct lttng_tracker_id **_ids)
1075 {
1076         struct lttng_tracker_list *tracker_list;
1077
1078         if (tracker_type == LTTNG_TRACKER_PID) {
1079                 DBG("Backward compatible behavior: translate PID tracker to VPID tracker for UST domain.");
1080                 tracker_type = LTTNG_TRACKER_VPID;
1081         }
1082
1083         tracker_list = get_id_tracker_list(session, tracker_type);
1084         if (!tracker_list) {
1085                 return -LTTNG_ERR_INVALID;
1086         }
1087         return lttng_tracker_id_get_list(tracker_list, _ids);
1088 }
1089
1090 /*
1091  * RCU safe free context structure.
1092  */
1093 static void destroy_context_rcu(struct rcu_head *head)
1094 {
1095         struct lttng_ht_node_ulong *node =
1096                 caa_container_of(head, struct lttng_ht_node_ulong, head);
1097         struct ltt_ust_context *ctx =
1098                 caa_container_of(node, struct ltt_ust_context, node);
1099
1100         trace_ust_destroy_context(ctx);
1101 }
1102
1103 /*
1104  * Cleanup UST context hash table.
1105  */
1106 static void destroy_contexts(struct lttng_ht *ht)
1107 {
1108         int ret;
1109         struct lttng_ht_node_ulong *node;
1110         struct lttng_ht_iter iter;
1111         struct ltt_ust_context *ctx;
1112
1113         assert(ht);
1114
1115         rcu_read_lock();
1116         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
1117                 /* Remove from ordered list. */
1118                 ctx = caa_container_of(node, struct ltt_ust_context, node);
1119                 cds_list_del(&ctx->list);
1120                 /* Remove from channel's hash table. */
1121                 ret = lttng_ht_del(ht, &iter);
1122                 if (!ret) {
1123                         call_rcu(&node->head, destroy_context_rcu);
1124                 }
1125         }
1126         rcu_read_unlock();
1127
1128         ht_cleanup_push(ht);
1129 }
1130
1131 /*
1132  * Cleanup ust event structure.
1133  */
1134 void trace_ust_destroy_event(struct ltt_ust_event *event)
1135 {
1136         assert(event);
1137
1138         DBG2("Trace destroy UST event %s", event->attr.name);
1139         free(event->filter_expression);
1140         free(event->filter);
1141         free(event->exclusion);
1142         free(event);
1143 }
1144
1145 /*
1146  * Cleanup ust context structure.
1147  */
1148 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1149 {
1150         assert(ctx);
1151
1152         if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1153                 free(ctx->ctx.u.app_ctx.provider_name);
1154                 free(ctx->ctx.u.app_ctx.ctx_name);
1155         }
1156         free(ctx);
1157 }
1158
1159 /*
1160  * URCU intermediate call to complete destroy event.
1161  */
1162 static void destroy_event_rcu(struct rcu_head *head)
1163 {
1164         struct lttng_ht_node_str *node =
1165                 caa_container_of(head, struct lttng_ht_node_str, head);
1166         struct ltt_ust_event *event =
1167                 caa_container_of(node, struct ltt_ust_event, node);
1168
1169         trace_ust_destroy_event(event);
1170 }
1171
1172 /*
1173  * Cleanup UST events hashtable.
1174  */
1175 static void destroy_events(struct lttng_ht *events)
1176 {
1177         int ret;
1178         struct lttng_ht_node_str *node;
1179         struct lttng_ht_iter iter;
1180
1181         assert(events);
1182
1183         rcu_read_lock();
1184         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1185                 ret = lttng_ht_del(events, &iter);
1186                 assert(!ret);
1187                 call_rcu(&node->head, destroy_event_rcu);
1188         }
1189         rcu_read_unlock();
1190
1191         ht_cleanup_push(events);
1192 }
1193
1194 /*
1195  * Cleanup ust channel structure.
1196  *
1197  * Should _NOT_ be called with RCU read lock held.
1198  */
1199 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1200 {
1201         assert(channel);
1202
1203         DBG2("Trace destroy UST channel %s", channel->name);
1204
1205         free(channel);
1206 }
1207
1208 /*
1209  * URCU intermediate call to complete destroy channel.
1210  */
1211 static void destroy_channel_rcu(struct rcu_head *head)
1212 {
1213         struct lttng_ht_node_str *node =
1214                 caa_container_of(head, struct lttng_ht_node_str, head);
1215         struct ltt_ust_channel *channel =
1216                 caa_container_of(node, struct ltt_ust_channel, node);
1217
1218         _trace_ust_destroy_channel(channel);
1219 }
1220
1221 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1222 {
1223         /* Destroying all events of the channel */
1224         destroy_events(channel->events);
1225         /* Destroying all context of the channel */
1226         destroy_contexts(channel->ctx);
1227
1228         call_rcu(&channel->node.head, destroy_channel_rcu);
1229 }
1230
1231 /*
1232  * Remove an UST channel from a channel HT.
1233  */
1234 void trace_ust_delete_channel(struct lttng_ht *ht,
1235                 struct ltt_ust_channel *channel)
1236 {
1237         int ret;
1238         struct lttng_ht_iter iter;
1239
1240         assert(ht);
1241         assert(channel);
1242
1243         iter.iter.node = &channel->node.node;
1244         ret = lttng_ht_del(ht, &iter);
1245         assert(!ret);
1246 }
1247
1248 /*
1249  * Iterate over a hash table containing channels and cleanup safely.
1250  */
1251 static void destroy_channels(struct lttng_ht *channels)
1252 {
1253         struct lttng_ht_node_str *node;
1254         struct lttng_ht_iter iter;
1255
1256         assert(channels);
1257
1258         rcu_read_lock();
1259         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1260                 struct ltt_ust_channel *chan =
1261                         caa_container_of(node, struct ltt_ust_channel, node);
1262
1263                 trace_ust_delete_channel(channels, chan);
1264                 trace_ust_destroy_channel(chan);
1265         }
1266         rcu_read_unlock();
1267
1268         ht_cleanup_push(channels);
1269 }
1270
1271 /*
1272  * Cleanup UST global domain.
1273  */
1274 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1275 {
1276         assert(dom);
1277
1278         destroy_channels(dom->channels);
1279 }
1280
1281 /*
1282  * Cleanup ust session structure
1283  *
1284  * Should *NOT* be called with RCU read-side lock held.
1285  */
1286 void trace_ust_destroy_session(struct ltt_ust_session *session)
1287 {
1288         struct agent *agt;
1289         struct buffer_reg_uid *reg, *sreg;
1290         struct lttng_ht_iter iter;
1291
1292         assert(session);
1293
1294         DBG2("Trace UST destroy session %" PRIu64, session->id);
1295
1296         /* Cleaning up UST domain */
1297         destroy_domain_global(&session->domain_global);
1298
1299         rcu_read_lock();
1300         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1301                 int ret = lttng_ht_del(session->agents, &iter);
1302
1303                 assert(!ret);
1304                 agent_destroy(agt);
1305         }
1306         rcu_read_unlock();
1307
1308         ht_cleanup_push(session->agents);
1309
1310         /* Cleanup UID buffer registry object(s). */
1311         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1312                         lnode) {
1313                 cds_list_del(&reg->lnode);
1314                 buffer_reg_uid_remove(reg);
1315                 buffer_reg_uid_destroy(reg, session->consumer);
1316         }
1317
1318         consumer_output_put(session->consumer);
1319
1320         lttng_tracker_list_destroy(session->tracker_list_vpid);
1321         lttng_tracker_list_destroy(session->tracker_list_vuid);
1322         lttng_tracker_list_destroy(session->tracker_list_vgid);
1323
1324         fini_id_tracker(&session->vpid_tracker);
1325         fini_id_tracker(&session->vuid_tracker);
1326         fini_id_tracker(&session->vgid_tracker);
1327
1328         free(session);
1329 }