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;
 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->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 316         if (lus->consumer == NULL) {
 317                 goto error_consumer;
 318         }
 319
 320         DBG2("UST trace session create successful");
 321
 322         return lus;
 323
 324 error_consumer:
 325         ht_cleanup_push(lus->domain_global.channels);
 326         ht_cleanup_push(lus->agents);
 327         free(lus);
 328 error:
 329         return NULL;
 330 }
 331
 332 /*
 333  * Allocate and initialize a ust channel data structure.
 334  *
 335  * Return pointer to structure or NULL.
 336  */
 337 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 338                 enum lttng_domain_type domain)
 339 {
 340         struct ltt_ust_channel *luc;
 341
 342         assert(chan);
 343
 344         luc = zmalloc(sizeof(struct ltt_ust_channel));
 345         if (luc == NULL) {
 346                 PERROR("ltt_ust_channel zmalloc");
 347                 goto error;
 348         }
 349
 350         luc->domain = domain;
 351
 352         /* Copy UST channel attributes */
 353         luc->attr.overwrite = chan->attr.overwrite;
 354         luc->attr.subbuf_size = chan->attr.subbuf_size;
 355         luc->attr.num_subbuf = chan->attr.num_subbuf;
 356         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 357         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 358         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 359
 360         /* Translate to UST output enum */
 361         switch (luc->attr.output) {
 362         default:
 363                 luc->attr.output = LTTNG_UST_MMAP;
 364                 break;
 365         }
 366
 367         /*
 368          * If we receive an empty string for channel name, it means the
 369          * default channel name is requested.
 370          */
 371         if (chan->name[0] == '\0') {
 372                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 373         } else {
 374                 /* Copy channel name */
 375                 strncpy(luc->name, chan->name, sizeof(luc->name));
 376         }
 377         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 378
 379         /* Init node */
 380         lttng_ht_node_init_str(&luc->node, luc->name);
 381         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 382
 383         /* Alloc hash tables */
 384         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 385         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 386
 387         /* On-disk circular buffer parameters */
 388         luc->tracefile_size = chan->attr.tracefile_size;
 389         luc->tracefile_count = chan->attr.tracefile_count;
 390
 391         DBG2("Trace UST channel %s created", luc->name);
 392
 393 error:
 394         return luc;
 395 }
 396
 397 /*
 398  * Validates an exclusion list.
 399  *
 400  * Returns 0 if valid, negative value if invalid.
 401  */
 402 static int validate_exclusion(struct lttng_event_exclusion *exclusion)
 403 {
 404         size_t i;
 405         int ret = 0;
 406
 407         assert(exclusion);
 408
 409         for (i = 0; i < exclusion->count; ++i) {
 410                 size_t j;
 411                 const char *name_a =
 412                         LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
 413
 414                 for (j = 0; j < i; ++j) {
 415                         const char *name_b =
 416                                 LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, j);
 417
 418                         if (!strncmp(name_a, name_b, LTTNG_SYMBOL_NAME_LEN)) {
 419                                 /* Match! */
 420                                 ret = -1;
 421                                 goto end;
 422                         }
 423                 }
 424         }
 425
 426 end:
 427         return ret;
 428 }
 429
 430 /*
 431  * Allocate and initialize a ust event. Set name and event type.
 432  * We own filter_expression, filter, and exclusion.
 433  *
 434  * Return pointer to structure or NULL.
 435  */
 436 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 437                 char *filter_expression,
 438                 struct lttng_filter_bytecode *filter,
 439                 struct lttng_event_exclusion *exclusion,
 440                 bool internal_event)
 441 {
 442         struct ltt_ust_event *lue;
 443
 444         assert(ev);
 445
 446         if (exclusion && validate_exclusion(exclusion)) {
 447                 goto error;
 448         }
 449
 450         lue = zmalloc(sizeof(struct ltt_ust_event));
 451         if (lue == NULL) {
 452                 PERROR("ust event zmalloc");
 453                 goto error;
 454         }
 455
 456         lue->internal = internal_event;
 457
 458         switch (ev->type) {
 459         case LTTNG_EVENT_PROBE:
 460                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 461                 break;
 462         case LTTNG_EVENT_FUNCTION:
 463                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 464                 break;
 465         case LTTNG_EVENT_FUNCTION_ENTRY:
 466                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 467                 break;
 468         case LTTNG_EVENT_TRACEPOINT:
 469                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 470                 break;
 471         default:
 472                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 473                 goto error_free_event;
 474         }
 475
 476         /* Copy event name */
 477         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 478         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 479
 480         switch (ev->loglevel_type) {
 481         case LTTNG_EVENT_LOGLEVEL_ALL:
 482                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 483                 lue->attr.loglevel = -1;        /* Force to -1 */
 484                 break;
 485         case LTTNG_EVENT_LOGLEVEL_RANGE:
 486                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 487                 lue->attr.loglevel = ev->loglevel;
 488                 break;
 489         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 490                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 491                 lue->attr.loglevel = ev->loglevel;
 492                 break;
 493         default:
 494                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 495                 goto error_free_event;
 496         }
 497
 498         /* Same layout. */
 499         lue->filter_expression = filter_expression;
 500         lue->filter = filter;
 501         lue->exclusion = exclusion;
 502
 503         /* Init node */
 504         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 505
 506         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 507                 lue->attr.name, lue->attr.loglevel_type,
 508                 lue->attr.loglevel);
 509
 510         return lue;
 511
 512 error_free_event:
 513         free(lue);
 514 error:
 515         free(filter_expression);
 516         free(filter);
 517         free(exclusion);
 518         return NULL;
 519 }
 520
 521 static
 522 int trace_ust_context_type_event_to_ust(
 523                 enum lttng_event_context_type type)
 524 {
 525         int utype;
 526
 527         switch (type) {
 528         case LTTNG_EVENT_CONTEXT_VTID:
 529                 utype = LTTNG_UST_CONTEXT_VTID;
 530                 break;
 531         case LTTNG_EVENT_CONTEXT_VPID:
 532                 utype = LTTNG_UST_CONTEXT_VPID;
 533                 break;
 534         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 535                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 536                 break;
 537         case LTTNG_EVENT_CONTEXT_PROCNAME:
 538                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 539                 break;
 540         case LTTNG_EVENT_CONTEXT_IP:
 541                 utype = LTTNG_UST_CONTEXT_IP;
 542                 break;
 543         case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
 544                 if (!ustctl_has_perf_counters()) {
 545                         utype = -1;
 546                         WARN("Perf counters not implemented in UST");
 547                 } else {
 548                         utype = LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER;
 549                 }
 550                 break;
 551         case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
 552                 utype = LTTNG_UST_CONTEXT_APP_CONTEXT;
 553                 break;
 554         default:
 555                 utype = -1;
 556                 break;
 557         }
 558         return utype;
 559 }
 560
 561 /*
 562  * Return 1 if contexts match, 0 otherwise.
 563  */
 564 int trace_ust_match_context(struct ltt_ust_context *uctx,
 565                 struct lttng_event_context *ctx)
 566 {
 567         int utype;
 568
 569         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 570         if (utype < 0) {
 571                 return 0;
 572         }
 573         if (uctx->ctx.ctx != utype) {
 574                 return 0;
 575         }
 576         switch (utype) {
 577         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 578                 if (uctx->ctx.u.perf_counter.type
 579                                 != ctx->u.perf_counter.type) {
 580                         return 0;
 581                 }
 582                 if (uctx->ctx.u.perf_counter.config
 583                                 != ctx->u.perf_counter.config) {
 584                         return 0;
 585                 }
 586                 if (strncmp(uctx->ctx.u.perf_counter.name,
 587                                 ctx->u.perf_counter.name,
 588                                 LTTNG_UST_SYM_NAME_LEN)) {
 589                         return 0;
 590                 }
 591                 break;
 592         default:
 593                 break;
 594
 595         }
 596         return 1;
 597 }
 598
 599 /*
 600  * Allocate and initialize an UST context.
 601  *
 602  * Return pointer to structure or NULL.
 603  */
 604 struct ltt_ust_context *trace_ust_create_context(
 605                 struct lttng_event_context *ctx)
 606 {
 607         struct ltt_ust_context *uctx = NULL;
 608         int utype;
 609
 610         assert(ctx);
 611
 612         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 613         if (utype < 0) {
 614                 ERR("Invalid UST context");
 615                 goto end;
 616         }
 617
 618         uctx = zmalloc(sizeof(struct ltt_ust_context));
 619         if (!uctx) {
 620                 PERROR("zmalloc ltt_ust_context");
 621                 goto end;
 622         }
 623
 624         uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
 625         switch (utype) {
 626         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 627                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 628                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 629                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 630                                 LTTNG_UST_SYM_NAME_LEN);
 631                 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 632                 break;
 633         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 634         {
 635                 char *provider_name = NULL, *ctx_name = NULL;
 636
 637                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 638                 if (!provider_name) {
 639                         goto error;
 640                 }
 641                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 642
 643                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 644                 if (!ctx_name) {
 645                         goto error;
 646                 }
 647                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 648                 break;
 649         }
 650         default:
 651                 break;
 652         }
 653         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 654 end:
 655         return uctx;
 656 error:
 657         trace_ust_destroy_context(uctx);
 658         return NULL;
 659 }
 660
 661 static
 662 void destroy_pid_tracker_node_rcu(struct rcu_head *head)
 663 {
 664         struct ust_pid_tracker_node *tracker_node =
 665                 caa_container_of(head, struct ust_pid_tracker_node, node.head);
 666         free(tracker_node);
 667 }
 668
 669 static
 670 void destroy_pid_tracker_node(struct ust_pid_tracker_node *tracker_node)
 671 {
 672
 673         call_rcu(&tracker_node->node.head, destroy_pid_tracker_node_rcu);
 674 }
 675
 676 static
 677 int init_pid_tracker(struct ust_pid_tracker *pid_tracker)
 678 {
 679         int ret = 0;
 680
 681         pid_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 682         if (!pid_tracker->ht) {
 683                 ret = -1;
 684                 goto end;
 685         }
 686
 687 end:
 688         return ret;
 689 }
 690
 691 /*
 692  * Teardown pid tracker content, but don't free pid_tracker object.
 693  */
 694 static
 695 void fini_pid_tracker(struct ust_pid_tracker *pid_tracker)
 696 {
 697         struct ust_pid_tracker_node *tracker_node;
 698         struct lttng_ht_iter iter;
 699
 700         if (!pid_tracker->ht) {
 701                 return;
 702         }
 703         rcu_read_lock();
 704         cds_lfht_for_each_entry(pid_tracker->ht->ht,
 705                         &iter.iter, tracker_node, node.node) {
 706                 int ret = lttng_ht_del(pid_tracker->ht, &iter);
 707
 708                 assert(!ret);
 709                 destroy_pid_tracker_node(tracker_node);
 710         }
 711         rcu_read_unlock();
 712         ht_cleanup_push(pid_tracker->ht);
 713         pid_tracker->ht = NULL;
 714 }
 715
 716 static
 717 struct ust_pid_tracker_node *pid_tracker_lookup(
 718                 struct ust_pid_tracker *pid_tracker, int pid,
 719                 struct lttng_ht_iter *iter)
 720 {
 721         unsigned long _pid = (unsigned long) pid;
 722         struct lttng_ht_node_ulong *node;
 723
 724         lttng_ht_lookup(pid_tracker->ht, (void *) _pid, iter);
 725         node = lttng_ht_iter_get_node_ulong(iter);
 726         if (node) {
 727                 return caa_container_of(node, struct ust_pid_tracker_node,
 728                         node);
 729         } else {
 730                 return NULL;
 731         }
 732 }
 733
 734 static
 735 int pid_tracker_add_pid(struct ust_pid_tracker *pid_tracker, int pid)
 736 {
 737         int retval = LTTNG_OK;
 738         struct ust_pid_tracker_node *tracker_node;
 739         struct lttng_ht_iter iter;
 740
 741         if (pid < 0) {
 742                 retval = LTTNG_ERR_INVALID;
 743                 goto end;
 744         }
 745         tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
 746         if (tracker_node) {
 747                 /* Already exists. */
 748                 retval = LTTNG_ERR_PID_TRACKED;
 749                 goto end;
 750         }
 751         tracker_node = zmalloc(sizeof(*tracker_node));
 752         if (!tracker_node) {
 753                 retval = LTTNG_ERR_NOMEM;
 754                 goto end;
 755         }
 756         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) pid);
 757         lttng_ht_add_unique_ulong(pid_tracker->ht, &tracker_node->node);
 758 end:
 759         return retval;
 760 }
 761
 762 static
 763 int pid_tracker_del_pid(struct ust_pid_tracker *pid_tracker, int pid)
 764 {
 765         int retval = LTTNG_OK, ret;
 766         struct ust_pid_tracker_node *tracker_node;
 767         struct lttng_ht_iter iter;
 768
 769         if (pid < 0) {
 770                 retval = LTTNG_ERR_INVALID;
 771                 goto end;
 772         }
 773         tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
 774         if (!tracker_node) {
 775                 /* Not found */
 776                 retval = LTTNG_ERR_PID_NOT_TRACKED;
 777                 goto end;
 778         }
 779         ret = lttng_ht_del(pid_tracker->ht, &iter);
 780         assert(!ret);
 781
 782         destroy_pid_tracker_node(tracker_node);
 783 end:
 784         return retval;
 785 }
 786
 787 /*
 788  * The session lock is held when calling this function.
 789  */
 790 int trace_ust_pid_tracker_lookup(struct ltt_ust_session *session, int pid)
 791 {
 792         struct lttng_ht_iter iter;
 793
 794         if (!session->pid_tracker.ht) {
 795                 return 1;
 796         }
 797         if (pid_tracker_lookup(&session->pid_tracker, pid, &iter)) {
 798                 return 1;
 799         }
 800         return 0;
 801 }
 802
 803 /*
 804  * Called with the session lock held.
 805  */
 806 int trace_ust_track_pid(struct ltt_ust_session *session, int pid)
 807 {
 808         int retval = LTTNG_OK;
 809
 810         if (pid == -1) {
 811                 /* Track all pids: destroy tracker if exists. */
 812                 if (session->pid_tracker.ht) {
 813                         fini_pid_tracker(&session->pid_tracker);
 814                         /* Ensure all apps have session. */
 815                         ust_app_global_update_all(session);
 816                 }
 817         } else {
 818                 int ret;
 819
 820                 if (!session->pid_tracker.ht) {
 821                         /* Create tracker. */
 822                         if (init_pid_tracker(&session->pid_tracker)) {
 823                                 ERR("Error initializing PID tracker");
 824                                 retval = LTTNG_ERR_NOMEM;
 825                                 goto end;
 826                         }
 827                         ret = pid_tracker_add_pid(&session->pid_tracker, pid);
 828                         if (ret != LTTNG_OK) {
 829                                 retval = ret;
 830                                 fini_pid_tracker(&session->pid_tracker);
 831                                 goto end;
 832                         }
 833                         /* Remove all apps from session except pid. */
 834                         ust_app_global_update_all(session);
 835                 } else {
 836                         struct ust_app *app;
 837
 838                         ret = pid_tracker_add_pid(&session->pid_tracker, pid);
 839                         if (ret != LTTNG_OK) {
 840                                 retval = ret;
 841                                 goto end;
 842                         }
 843                         /* Add session to application */
 844                         app = ust_app_find_by_pid(pid);
 845                         if (app) {
 846                                 ust_app_global_update(session, app);
 847                         }
 848                 }
 849         }
 850 end:
 851         return retval;
 852 }
 853
 854 /*
 855  * Called with the session lock held.
 856  */
 857 int trace_ust_untrack_pid(struct ltt_ust_session *session, int pid)
 858 {
 859         int retval = LTTNG_OK;
 860
 861         if (pid == -1) {
 862                 /* Create empty tracker, replace old tracker. */
 863                 struct ust_pid_tracker tmp_tracker;
 864
 865                 tmp_tracker = session->pid_tracker;
 866                 if (init_pid_tracker(&session->pid_tracker)) {
 867                         ERR("Error initializing PID tracker");
 868                         retval = LTTNG_ERR_NOMEM;
 869                         /* Rollback operation. */
 870                         session->pid_tracker = tmp_tracker;
 871                         goto end;
 872                 }
 873                 fini_pid_tracker(&tmp_tracker);
 874
 875                 /* Remove session from all applications */
 876                 ust_app_global_update_all(session);
 877         } else {
 878                 int ret;
 879                 struct ust_app *app;
 880
 881                 if (!session->pid_tracker.ht) {
 882                         /* No PID being tracked. */
 883                         retval = LTTNG_ERR_PID_NOT_TRACKED;
 884                         goto end;
 885                 }
 886                 /* Remove PID from tracker */
 887                 ret = pid_tracker_del_pid(&session->pid_tracker, pid);
 888                 if (ret != LTTNG_OK) {
 889                         retval = ret;
 890                         goto end;
 891                 }
 892                 /* Remove session from application. */
 893                 app = ust_app_find_by_pid(pid);
 894                 if (app) {
 895                         ust_app_global_update(session, app);
 896                 }
 897         }
 898 end:
 899         return retval;
 900 }
 901
 902 /*
 903  * Called with session lock held.
 904  */
 905 ssize_t trace_ust_list_tracker_pids(struct ltt_ust_session *session,
 906                 int32_t **_pids)
 907 {
 908         struct ust_pid_tracker_node *tracker_node;
 909         struct lttng_ht_iter iter;
 910         unsigned long count, i = 0;
 911         long approx[2];
 912         int32_t *pids;
 913         int ret = 0;
 914
 915         if (!session->pid_tracker.ht) {
 916                 /* Tracker disabled. Set first entry to -1. */
 917                 pids = zmalloc(sizeof(*pids));
 918                 if (!pids) {
 919                         ret = -1;
 920                         goto end;
 921                 }
 922                 pids[0] = -1;
 923                 *_pids = pids;
 924                 return 1;
 925         }
 926
 927         rcu_read_lock();
 928         cds_lfht_count_nodes(session->pid_tracker.ht->ht,
 929                 &approx[0], &count, &approx[1]);
 930         pids = zmalloc(sizeof(*pids) * count);
 931         if (!pids) {
 932                 ret = -1;
 933                 goto end;
 934         }
 935         cds_lfht_for_each_entry(session->pid_tracker.ht->ht,
 936                         &iter.iter, tracker_node, node.node) {
 937                 pids[i++] = tracker_node->node.key;
 938         }
 939         *_pids = pids;
 940         ret = count;
 941 end:
 942         rcu_read_unlock();
 943         return ret;
 944 }
 945
 946 /*
 947  * RCU safe free context structure.
 948  */
 949 static void destroy_context_rcu(struct rcu_head *head)
 950 {
 951         struct lttng_ht_node_ulong *node =
 952                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 953         struct ltt_ust_context *ctx =
 954                 caa_container_of(node, struct ltt_ust_context, node);
 955
 956         trace_ust_destroy_context(ctx);
 957 }
 958
 959 /*
 960  * Cleanup UST context hash table.
 961  */
 962 static void destroy_contexts(struct lttng_ht *ht)
 963 {
 964         int ret;
 965         struct lttng_ht_node_ulong *node;
 966         struct lttng_ht_iter iter;
 967         struct ltt_ust_context *ctx;
 968
 969         assert(ht);
 970
 971         rcu_read_lock();
 972         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 973                 /* Remove from ordered list. */
 974                 ctx = caa_container_of(node, struct ltt_ust_context, node);
 975                 cds_list_del(&ctx->list);
 976                 /* Remove from channel's hash table. */
 977                 ret = lttng_ht_del(ht, &iter);
 978                 if (!ret) {
 979                         call_rcu(&node->head, destroy_context_rcu);
 980                 }
 981         }
 982         rcu_read_unlock();
 983
 984         ht_cleanup_push(ht);
 985 }
 986
 987 /*
 988  * Cleanup ust event structure.
 989  */
 990 void trace_ust_destroy_event(struct ltt_ust_event *event)
 991 {
 992         assert(event);
 993
 994         DBG2("Trace destroy UST event %s", event->attr.name);
 995         free(event->filter_expression);
 996         free(event->filter);
 997         free(event->exclusion);
 998         free(event);
 999 }
1000
1001 /*
1002  * Cleanup ust context structure.
1003  */
1004 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1005 {
1006         assert(ctx);
1007
1008         if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1009                 free(ctx->ctx.u.app_ctx.provider_name);
1010                 free(ctx->ctx.u.app_ctx.ctx_name);
1011         }
1012         free(ctx);
1013 }
1014
1015 /*
1016  * URCU intermediate call to complete destroy event.
1017  */
1018 static void destroy_event_rcu(struct rcu_head *head)
1019 {
1020         struct lttng_ht_node_str *node =
1021                 caa_container_of(head, struct lttng_ht_node_str, head);
1022         struct ltt_ust_event *event =
1023                 caa_container_of(node, struct ltt_ust_event, node);
1024
1025         trace_ust_destroy_event(event);
1026 }
1027
1028 /*
1029  * Cleanup UST events hashtable.
1030  */
1031 static void destroy_events(struct lttng_ht *events)
1032 {
1033         int ret;
1034         struct lttng_ht_node_str *node;
1035         struct lttng_ht_iter iter;
1036
1037         assert(events);
1038
1039         rcu_read_lock();
1040         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1041                 ret = lttng_ht_del(events, &iter);
1042                 assert(!ret);
1043                 call_rcu(&node->head, destroy_event_rcu);
1044         }
1045         rcu_read_unlock();
1046
1047         ht_cleanup_push(events);
1048 }
1049
1050 /*
1051  * Cleanup ust channel structure.
1052  *
1053  * Should _NOT_ be called with RCU read lock held.
1054  */
1055 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1056 {
1057         assert(channel);
1058
1059         DBG2("Trace destroy UST channel %s", channel->name);
1060
1061         free(channel);
1062 }
1063
1064 /*
1065  * URCU intermediate call to complete destroy channel.
1066  */
1067 static void destroy_channel_rcu(struct rcu_head *head)
1068 {
1069         struct lttng_ht_node_str *node =
1070                 caa_container_of(head, struct lttng_ht_node_str, head);
1071         struct ltt_ust_channel *channel =
1072                 caa_container_of(node, struct ltt_ust_channel, node);
1073
1074         _trace_ust_destroy_channel(channel);
1075 }
1076
1077 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1078 {
1079         /* Destroying all events of the channel */
1080         destroy_events(channel->events);
1081         /* Destroying all context of the channel */
1082         destroy_contexts(channel->ctx);
1083
1084         call_rcu(&channel->node.head, destroy_channel_rcu);
1085 }
1086
1087 /*
1088  * Remove an UST channel from a channel HT.
1089  */
1090 void trace_ust_delete_channel(struct lttng_ht *ht,
1091                 struct ltt_ust_channel *channel)
1092 {
1093         int ret;
1094         struct lttng_ht_iter iter;
1095
1096         assert(ht);
1097         assert(channel);
1098
1099         iter.iter.node = &channel->node.node;
1100         ret = lttng_ht_del(ht, &iter);
1101         assert(!ret);
1102 }
1103
1104 /*
1105  * Iterate over a hash table containing channels and cleanup safely.
1106  */
1107 static void destroy_channels(struct lttng_ht *channels)
1108 {
1109         struct lttng_ht_node_str *node;
1110         struct lttng_ht_iter iter;
1111
1112         assert(channels);
1113
1114         rcu_read_lock();
1115         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1116                 struct ltt_ust_channel *chan =
1117                         caa_container_of(node, struct ltt_ust_channel, node);
1118
1119                 trace_ust_delete_channel(channels, chan);
1120                 trace_ust_destroy_channel(chan);
1121         }
1122         rcu_read_unlock();
1123
1124         ht_cleanup_push(channels);
1125 }
1126
1127 /*
1128  * Cleanup UST global domain.
1129  */
1130 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1131 {
1132         assert(dom);
1133
1134         destroy_channels(dom->channels);
1135 }
1136
1137 /*
1138  * Cleanup ust session structure
1139  *
1140  * Should *NOT* be called with RCU read-side lock held.
1141  */
1142 void trace_ust_destroy_session(struct ltt_ust_session *session)
1143 {
1144         struct agent *agt;
1145         struct buffer_reg_uid *reg, *sreg;
1146         struct lttng_ht_iter iter;
1147
1148         assert(session);
1149
1150         DBG2("Trace UST destroy session %" PRIu64, session->id);
1151
1152         /* Cleaning up UST domain */
1153         destroy_domain_global(&session->domain_global);
1154
1155         rcu_read_lock();
1156         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1157                 int ret = lttng_ht_del(session->agents, &iter);
1158
1159                 assert(!ret);
1160                 agent_destroy(agt);
1161         }
1162         rcu_read_unlock();
1163
1164         ht_cleanup_push(session->agents);
1165
1166         /* Cleanup UID buffer registry object(s). */
1167         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1168                         lnode) {
1169                 cds_list_del(&reg->lnode);
1170                 buffer_reg_uid_remove(reg);
1171                 buffer_reg_uid_destroy(reg, session->consumer);
1172         }
1173
1174         consumer_output_put(session->consumer);
1175
1176         fini_pid_tracker(&session->pid_tracker);
1177
1178         free(session);
1179 }