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         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 593                 assert(uctx->ctx.u.app_ctx.provider_name);
 594                 assert(uctx->ctx.u.app_ctx.ctx_name);
 595                 if (strcmp(uctx->ctx.u.app_ctx.provider_name,
 596                                 ctx->u.app_ctx.provider_name) ||
 597                                 strcmp(uctx->ctx.u.app_ctx.ctx_name,
 598                                 ctx->u.app_ctx.ctx_name)) {
 599                         return 0;
 600                 }
 601         default:
 602                 break;
 603
 604         }
 605         return 1;
 606 }
 607
 608 /*
 609  * Allocate and initialize an UST context.
 610  *
 611  * Return pointer to structure or NULL.
 612  */
 613 struct ltt_ust_context *trace_ust_create_context(
 614                 struct lttng_event_context *ctx)
 615 {
 616         struct ltt_ust_context *uctx = NULL;
 617         int utype;
 618
 619         assert(ctx);
 620
 621         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 622         if (utype < 0) {
 623                 ERR("Invalid UST context");
 624                 goto end;
 625         }
 626
 627         uctx = zmalloc(sizeof(struct ltt_ust_context));
 628         if (!uctx) {
 629                 PERROR("zmalloc ltt_ust_context");
 630                 goto end;
 631         }
 632
 633         uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
 634         switch (utype) {
 635         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 636                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 637                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 638                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 639                                 LTTNG_UST_SYM_NAME_LEN);
 640                 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 641                 break;
 642         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 643         {
 644                 char *provider_name = NULL, *ctx_name = NULL;
 645
 646                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 647                 if (!provider_name) {
 648                         goto error;
 649                 }
 650                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 651
 652                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 653                 if (!ctx_name) {
 654                         goto error;
 655                 }
 656                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 657                 break;
 658         }
 659         default:
 660                 break;
 661         }
 662         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 663 end:
 664         return uctx;
 665 error:
 666         trace_ust_destroy_context(uctx);
 667         return NULL;
 668 }
 669
 670 static
 671 void destroy_pid_tracker_node_rcu(struct rcu_head *head)
 672 {
 673         struct ust_pid_tracker_node *tracker_node =
 674                 caa_container_of(head, struct ust_pid_tracker_node, node.head);
 675         free(tracker_node);
 676 }
 677
 678 static
 679 void destroy_pid_tracker_node(struct ust_pid_tracker_node *tracker_node)
 680 {
 681
 682         call_rcu(&tracker_node->node.head, destroy_pid_tracker_node_rcu);
 683 }
 684
 685 static
 686 int init_pid_tracker(struct ust_pid_tracker *pid_tracker)
 687 {
 688         int ret = 0;
 689
 690         pid_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 691         if (!pid_tracker->ht) {
 692                 ret = -1;
 693                 goto end;
 694         }
 695
 696 end:
 697         return ret;
 698 }
 699
 700 /*
 701  * Teardown pid tracker content, but don't free pid_tracker object.
 702  */
 703 static
 704 void fini_pid_tracker(struct ust_pid_tracker *pid_tracker)
 705 {
 706         struct ust_pid_tracker_node *tracker_node;
 707         struct lttng_ht_iter iter;
 708
 709         if (!pid_tracker->ht) {
 710                 return;
 711         }
 712         rcu_read_lock();
 713         cds_lfht_for_each_entry(pid_tracker->ht->ht,
 714                         &iter.iter, tracker_node, node.node) {
 715                 int ret = lttng_ht_del(pid_tracker->ht, &iter);
 716
 717                 assert(!ret);
 718                 destroy_pid_tracker_node(tracker_node);
 719         }
 720         rcu_read_unlock();
 721         ht_cleanup_push(pid_tracker->ht);
 722         pid_tracker->ht = NULL;
 723 }
 724
 725 static
 726 struct ust_pid_tracker_node *pid_tracker_lookup(
 727                 struct ust_pid_tracker *pid_tracker, int pid,
 728                 struct lttng_ht_iter *iter)
 729 {
 730         unsigned long _pid = (unsigned long) pid;
 731         struct lttng_ht_node_ulong *node;
 732
 733         lttng_ht_lookup(pid_tracker->ht, (void *) _pid, iter);
 734         node = lttng_ht_iter_get_node_ulong(iter);
 735         if (node) {
 736                 return caa_container_of(node, struct ust_pid_tracker_node,
 737                         node);
 738         } else {
 739                 return NULL;
 740         }
 741 }
 742
 743 static
 744 int pid_tracker_add_pid(struct ust_pid_tracker *pid_tracker, int pid)
 745 {
 746         int retval = LTTNG_OK;
 747         struct ust_pid_tracker_node *tracker_node;
 748         struct lttng_ht_iter iter;
 749
 750         if (pid < 0) {
 751                 retval = LTTNG_ERR_INVALID;
 752                 goto end;
 753         }
 754         tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
 755         if (tracker_node) {
 756                 /* Already exists. */
 757                 retval = LTTNG_ERR_PID_TRACKED;
 758                 goto end;
 759         }
 760         tracker_node = zmalloc(sizeof(*tracker_node));
 761         if (!tracker_node) {
 762                 retval = LTTNG_ERR_NOMEM;
 763                 goto end;
 764         }
 765         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) pid);
 766         lttng_ht_add_unique_ulong(pid_tracker->ht, &tracker_node->node);
 767 end:
 768         return retval;
 769 }
 770
 771 static
 772 int pid_tracker_del_pid(struct ust_pid_tracker *pid_tracker, int pid)
 773 {
 774         int retval = LTTNG_OK, ret;
 775         struct ust_pid_tracker_node *tracker_node;
 776         struct lttng_ht_iter iter;
 777
 778         if (pid < 0) {
 779                 retval = LTTNG_ERR_INVALID;
 780                 goto end;
 781         }
 782         tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
 783         if (!tracker_node) {
 784                 /* Not found */
 785                 retval = LTTNG_ERR_PID_NOT_TRACKED;
 786                 goto end;
 787         }
 788         ret = lttng_ht_del(pid_tracker->ht, &iter);
 789         assert(!ret);
 790
 791         destroy_pid_tracker_node(tracker_node);
 792 end:
 793         return retval;
 794 }
 795
 796 /*
 797  * The session lock is held when calling this function.
 798  */
 799 int trace_ust_pid_tracker_lookup(struct ltt_ust_session *session, int pid)
 800 {
 801         struct lttng_ht_iter iter;
 802
 803         if (!session->pid_tracker.ht) {
 804                 return 1;
 805         }
 806         if (pid_tracker_lookup(&session->pid_tracker, pid, &iter)) {
 807                 return 1;
 808         }
 809         return 0;
 810 }
 811
 812 /*
 813  * Called with the session lock held.
 814  */
 815 int trace_ust_track_pid(struct ltt_ust_session *session, int pid)
 816 {
 817         int retval = LTTNG_OK;
 818
 819         if (pid == -1) {
 820                 /* Track all pids: destroy tracker if exists. */
 821                 if (session->pid_tracker.ht) {
 822                         fini_pid_tracker(&session->pid_tracker);
 823                         /* Ensure all apps have session. */
 824                         ust_app_global_update_all(session);
 825                 }
 826         } else {
 827                 int ret;
 828
 829                 if (!session->pid_tracker.ht) {
 830                         /* Create tracker. */
 831                         if (init_pid_tracker(&session->pid_tracker)) {
 832                                 ERR("Error initializing PID tracker");
 833                                 retval = LTTNG_ERR_NOMEM;
 834                                 goto end;
 835                         }
 836                         ret = pid_tracker_add_pid(&session->pid_tracker, pid);
 837                         if (ret != LTTNG_OK) {
 838                                 retval = ret;
 839                                 fini_pid_tracker(&session->pid_tracker);
 840                                 goto end;
 841                         }
 842                         /* Remove all apps from session except pid. */
 843                         ust_app_global_update_all(session);
 844                 } else {
 845                         struct ust_app *app;
 846
 847                         ret = pid_tracker_add_pid(&session->pid_tracker, pid);
 848                         if (ret != LTTNG_OK) {
 849                                 retval = ret;
 850                                 goto end;
 851                         }
 852                         /* Add session to application */
 853                         app = ust_app_find_by_pid(pid);
 854                         if (app) {
 855                                 ust_app_global_update(session, app);
 856                         }
 857                 }
 858         }
 859 end:
 860         return retval;
 861 }
 862
 863 /*
 864  * Called with the session lock held.
 865  */
 866 int trace_ust_untrack_pid(struct ltt_ust_session *session, int pid)
 867 {
 868         int retval = LTTNG_OK;
 869
 870         if (pid == -1) {
 871                 /* Create empty tracker, replace old tracker. */
 872                 struct ust_pid_tracker tmp_tracker;
 873
 874                 tmp_tracker = session->pid_tracker;
 875                 if (init_pid_tracker(&session->pid_tracker)) {
 876                         ERR("Error initializing PID tracker");
 877                         retval = LTTNG_ERR_NOMEM;
 878                         /* Rollback operation. */
 879                         session->pid_tracker = tmp_tracker;
 880                         goto end;
 881                 }
 882                 fini_pid_tracker(&tmp_tracker);
 883
 884                 /* Remove session from all applications */
 885                 ust_app_global_update_all(session);
 886         } else {
 887                 int ret;
 888                 struct ust_app *app;
 889
 890                 if (!session->pid_tracker.ht) {
 891                         /* No PID being tracked. */
 892                         retval = LTTNG_ERR_PID_NOT_TRACKED;
 893                         goto end;
 894                 }
 895                 /* Remove PID from tracker */
 896                 ret = pid_tracker_del_pid(&session->pid_tracker, pid);
 897                 if (ret != LTTNG_OK) {
 898                         retval = ret;
 899                         goto end;
 900                 }
 901                 /* Remove session from application. */
 902                 app = ust_app_find_by_pid(pid);
 903                 if (app) {
 904                         ust_app_global_update(session, app);
 905                 }
 906         }
 907 end:
 908         return retval;
 909 }
 910
 911 /*
 912  * Called with session lock held.
 913  */
 914 ssize_t trace_ust_list_tracker_pids(struct ltt_ust_session *session,
 915                 int32_t **_pids)
 916 {
 917         struct ust_pid_tracker_node *tracker_node;
 918         struct lttng_ht_iter iter;
 919         unsigned long count, i = 0;
 920         long approx[2];
 921         int32_t *pids;
 922         int ret = 0;
 923
 924         if (!session->pid_tracker.ht) {
 925                 /* Tracker disabled. Set first entry to -1. */
 926                 pids = zmalloc(sizeof(*pids));
 927                 if (!pids) {
 928                         ret = -1;
 929                         goto end;
 930                 }
 931                 pids[0] = -1;
 932                 *_pids = pids;
 933                 return 1;
 934         }
 935
 936         rcu_read_lock();
 937         cds_lfht_count_nodes(session->pid_tracker.ht->ht,
 938                 &approx[0], &count, &approx[1]);
 939         pids = zmalloc(sizeof(*pids) * count);
 940         if (!pids) {
 941                 ret = -1;
 942                 goto end;
 943         }
 944         cds_lfht_for_each_entry(session->pid_tracker.ht->ht,
 945                         &iter.iter, tracker_node, node.node) {
 946                 pids[i++] = tracker_node->node.key;
 947         }
 948         *_pids = pids;
 949         ret = count;
 950 end:
 951         rcu_read_unlock();
 952         return ret;
 953 }
 954
 955 /*
 956  * RCU safe free context structure.
 957  */
 958 static void destroy_context_rcu(struct rcu_head *head)
 959 {
 960         struct lttng_ht_node_ulong *node =
 961                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 962         struct ltt_ust_context *ctx =
 963                 caa_container_of(node, struct ltt_ust_context, node);
 964
 965         trace_ust_destroy_context(ctx);
 966 }
 967
 968 /*
 969  * Cleanup UST context hash table.
 970  */
 971 static void destroy_contexts(struct lttng_ht *ht)
 972 {
 973         int ret;
 974         struct lttng_ht_node_ulong *node;
 975         struct lttng_ht_iter iter;
 976         struct ltt_ust_context *ctx;
 977
 978         assert(ht);
 979
 980         rcu_read_lock();
 981         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 982                 /* Remove from ordered list. */
 983                 ctx = caa_container_of(node, struct ltt_ust_context, node);
 984                 cds_list_del(&ctx->list);
 985                 /* Remove from channel's hash table. */
 986                 ret = lttng_ht_del(ht, &iter);
 987                 if (!ret) {
 988                         call_rcu(&node->head, destroy_context_rcu);
 989                 }
 990         }
 991         rcu_read_unlock();
 992
 993         ht_cleanup_push(ht);
 994 }
 995
 996 /*
 997  * Cleanup ust event structure.
 998  */
 999 void trace_ust_destroy_event(struct ltt_ust_event *event)
1000 {
1001         assert(event);
1002
1003         DBG2("Trace destroy UST event %s", event->attr.name);
1004         free(event->filter_expression);
1005         free(event->filter);
1006         free(event->exclusion);
1007         free(event);
1008 }
1009
1010 /*
1011  * Cleanup ust context structure.
1012  */
1013 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1014 {
1015         assert(ctx);
1016
1017         if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1018                 free(ctx->ctx.u.app_ctx.provider_name);
1019                 free(ctx->ctx.u.app_ctx.ctx_name);
1020         }
1021         free(ctx);
1022 }
1023
1024 /*
1025  * URCU intermediate call to complete destroy event.
1026  */
1027 static void destroy_event_rcu(struct rcu_head *head)
1028 {
1029         struct lttng_ht_node_str *node =
1030                 caa_container_of(head, struct lttng_ht_node_str, head);
1031         struct ltt_ust_event *event =
1032                 caa_container_of(node, struct ltt_ust_event, node);
1033
1034         trace_ust_destroy_event(event);
1035 }
1036
1037 /*
1038  * Cleanup UST events hashtable.
1039  */
1040 static void destroy_events(struct lttng_ht *events)
1041 {
1042         int ret;
1043         struct lttng_ht_node_str *node;
1044         struct lttng_ht_iter iter;
1045
1046         assert(events);
1047
1048         rcu_read_lock();
1049         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1050                 ret = lttng_ht_del(events, &iter);
1051                 assert(!ret);
1052                 call_rcu(&node->head, destroy_event_rcu);
1053         }
1054         rcu_read_unlock();
1055
1056         ht_cleanup_push(events);
1057 }
1058
1059 /*
1060  * Cleanup ust channel structure.
1061  *
1062  * Should _NOT_ be called with RCU read lock held.
1063  */
1064 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1065 {
1066         assert(channel);
1067
1068         DBG2("Trace destroy UST channel %s", channel->name);
1069
1070         free(channel);
1071 }
1072
1073 /*
1074  * URCU intermediate call to complete destroy channel.
1075  */
1076 static void destroy_channel_rcu(struct rcu_head *head)
1077 {
1078         struct lttng_ht_node_str *node =
1079                 caa_container_of(head, struct lttng_ht_node_str, head);
1080         struct ltt_ust_channel *channel =
1081                 caa_container_of(node, struct ltt_ust_channel, node);
1082
1083         _trace_ust_destroy_channel(channel);
1084 }
1085
1086 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1087 {
1088         /* Destroying all events of the channel */
1089         destroy_events(channel->events);
1090         /* Destroying all context of the channel */
1091         destroy_contexts(channel->ctx);
1092
1093         call_rcu(&channel->node.head, destroy_channel_rcu);
1094 }
1095
1096 /*
1097  * Remove an UST channel from a channel HT.
1098  */
1099 void trace_ust_delete_channel(struct lttng_ht *ht,
1100                 struct ltt_ust_channel *channel)
1101 {
1102         int ret;
1103         struct lttng_ht_iter iter;
1104
1105         assert(ht);
1106         assert(channel);
1107
1108         iter.iter.node = &channel->node.node;
1109         ret = lttng_ht_del(ht, &iter);
1110         assert(!ret);
1111 }
1112
1113 /*
1114  * Iterate over a hash table containing channels and cleanup safely.
1115  */
1116 static void destroy_channels(struct lttng_ht *channels)
1117 {
1118         struct lttng_ht_node_str *node;
1119         struct lttng_ht_iter iter;
1120
1121         assert(channels);
1122
1123         rcu_read_lock();
1124         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1125                 struct ltt_ust_channel *chan =
1126                         caa_container_of(node, struct ltt_ust_channel, node);
1127
1128                 trace_ust_delete_channel(channels, chan);
1129                 trace_ust_destroy_channel(chan);
1130         }
1131         rcu_read_unlock();
1132
1133         ht_cleanup_push(channels);
1134 }
1135
1136 /*
1137  * Cleanup UST global domain.
1138  */
1139 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1140 {
1141         assert(dom);
1142
1143         destroy_channels(dom->channels);
1144 }
1145
1146 /*
1147  * Cleanup ust session structure
1148  *
1149  * Should *NOT* be called with RCU read-side lock held.
1150  */
1151 void trace_ust_destroy_session(struct ltt_ust_session *session)
1152 {
1153         struct agent *agt;
1154         struct buffer_reg_uid *reg, *sreg;
1155         struct lttng_ht_iter iter;
1156
1157         assert(session);
1158
1159         DBG2("Trace UST destroy session %" PRIu64, session->id);
1160
1161         /* Cleaning up UST domain */
1162         destroy_domain_global(&session->domain_global);
1163
1164         rcu_read_lock();
1165         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1166                 int ret = lttng_ht_del(session->agents, &iter);
1167
1168                 assert(!ret);
1169                 agent_destroy(agt);
1170         }
1171         rcu_read_unlock();
1172
1173         ht_cleanup_push(session->agents);
1174
1175         /* Cleanup UID buffer registry object(s). */
1176         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1177                         lnode) {
1178                 cds_list_del(&reg->lnode);
1179                 buffer_reg_uid_remove(reg);
1180                 buffer_reg_uid_destroy(reg, session->consumer);
1181         }
1182
1183         consumer_output_put(session->consumer);
1184
1185         fini_pid_tracker(&session->pid_tracker);
1186
1187         free(session);
1188 }