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

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <inttypes.h>
  24
  25 #include <common/common.h>
  26 #include <common/defaults.h>
  27
  28 #include "buffer-registry.h"
  29 #include "trace-ust.h"
  30 #include "utils.h"
  31 #include "ust-app.h"
  32 #include "agent.h"
  33
  34 /*
  35  * Match function for the events hash table lookup.
  36  *
  37  * Matches by name only. Used by the disable command.
  38  */
  39 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  40                 const void *_key)
  41 {
  42         struct ltt_ust_event *event;
  43         const char *name;
  44
  45         assert(node);
  46         assert(_key);
  47
  48         event = caa_container_of(node, struct ltt_ust_event, node.node);
  49         name = _key;
  50
  51         /* Event name */
  52         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  53                 goto no_match;
  54         }
  55
  56         /* Match */
  57         return 1;
  58
  59 no_match:
  60         return 0;
  61 }
  62
  63 /*
  64  * Match function for the hash table lookup.
  65  *
  66  * It matches an ust event based on three attributes which are the event name,
  67  * the filter bytecode and the loglevel.
  68  */
  69 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  70 {
  71         struct ltt_ust_event *event;
  72         const struct ltt_ust_ht_key *key;
  73         int ev_loglevel_value;
  74         int ll_match;
  75
  76         assert(node);
  77         assert(_key);
  78
  79         event = caa_container_of(node, struct ltt_ust_event, node.node);
  80         key = _key;
  81         ev_loglevel_value = event->attr.loglevel;
  82
  83         /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
  84
  85         /* Event name */
  86         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  87                 goto no_match;
  88         }
  89
  90         /* Event loglevel value and type. */
  91         ll_match = loglevels_match(event->attr.loglevel_type,
  92                 ev_loglevel_value, key->loglevel_type,
  93                 key->loglevel_value, LTTNG_UST_LOGLEVEL_ALL);
  94
  95         if (!ll_match) {
  96                 goto no_match;
  97         }
  98
  99         /* Only one of the filters is NULL, fail. */
 100         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 101                 goto no_match;
 102         }
 103
 104         if (key->filter && event->filter) {
 105                 /* Both filters exists, check length followed by the bytecode. */
 106                 if (event->filter->len != key->filter->len ||
 107                                 memcmp(event->filter->data, key->filter->data,
 108                                         event->filter->len) != 0) {
 109                         goto no_match;
 110                 }
 111         }
 112
 113         /* If only one of the exclusions is NULL, fail. */
 114         if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
 115                 goto no_match;
 116         }
 117
 118         if (key->exclusion && event->exclusion) {
 119                 size_t i;
 120
 121                 /* Check exclusion counts first. */
 122                 if (event->exclusion->count != key->exclusion->count) {
 123                         goto no_match;
 124                 }
 125
 126                 /* Compare names individually. */
 127                 for (i = 0; i < event->exclusion->count; ++i) {
 128                         size_t j;
 129                         bool found = false;
 130                         const char *name_ev =
 131                                 LTTNG_EVENT_EXCLUSION_NAME_AT(
 132                                         event->exclusion, i);
 133
 134                         /*
 135                          * Compare this exclusion name to all the key's
 136                          * exclusion names.
 137                          */
 138                         for (j = 0; j < key->exclusion->count; ++j) {
 139                                 const char *name_key =
 140                                         LTTNG_EVENT_EXCLUSION_NAME_AT(
 141                                                 key->exclusion, j);
 142
 143                                 if (!strncmp(name_ev, name_key,
 144                                                 LTTNG_SYMBOL_NAME_LEN)) {
 145                                         /* Names match! */
 146                                         found = true;
 147                                         break;
 148                                 }
 149                         }
 150
 151                         /*
 152                          * If the current exclusion name was not found amongst
 153                          * the key's exclusion names, then there's no match.
 154                          */
 155                         if (!found) {
 156                                 goto no_match;
 157                         }
 158                 }
 159         }
 160         /* Match. */
 161         return 1;
 162
 163 no_match:
 164         return 0;
 165 }
 166
 167 /*
 168  * Find the channel in the hashtable and return channel pointer. RCU read side
 169  * lock MUST be acquired before calling this.
 170  */
 171 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 172                 char *name)
 173 {
 174         struct lttng_ht_node_str *node;
 175         struct lttng_ht_iter iter;
 176
 177         /*
 178          * If we receive an empty string for channel name, it means the
 179          * default channel name is requested.
 180          */
 181         if (name[0] == '\0')
 182                 name = DEFAULT_CHANNEL_NAME;
 183
 184         lttng_ht_lookup(ht, (void *)name, &iter);
 185         node = lttng_ht_iter_get_node_str(&iter);
 186         if (node == NULL) {
 187                 goto error;
 188         }
 189
 190         DBG2("Trace UST channel %s found by name", name);
 191
 192         return caa_container_of(node, struct ltt_ust_channel, node);
 193
 194 error:
 195         DBG2("Trace UST channel %s not found by name", name);
 196         return NULL;
 197 }
 198
 199 /*
 200  * Find the event in the hashtable and return event pointer. RCU read side lock
 201  * MUST be acquired before calling this.
 202  */
 203 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 204                 char *name, struct lttng_filter_bytecode *filter,
 205                 enum lttng_ust_loglevel_type loglevel_type, int loglevel_value,
 206                 struct lttng_event_exclusion *exclusion)
 207 {
 208         struct lttng_ht_node_str *node;
 209         struct lttng_ht_iter iter;
 210         struct ltt_ust_ht_key key;
 211
 212         assert(name);
 213         assert(ht);
 214
 215         key.name = name;
 216         key.filter = filter;
 217         key.loglevel_type = loglevel_type;
 218         key.loglevel_value = loglevel_value;
 219         key.exclusion = exclusion;
 220
 221         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 222                         trace_ust_ht_match_event, &key, &iter.iter);
 223         node = lttng_ht_iter_get_node_str(&iter);
 224         if (node == NULL) {
 225                 goto error;
 226         }
 227
 228         DBG2("Trace UST event %s found", key.name);
 229
 230         return caa_container_of(node, struct ltt_ust_event, node);
 231
 232 error:
 233         DBG2("Trace UST event %s NOT found", key.name);
 234         return NULL;
 235 }
 236
 237 /*
 238  * Lookup an agent in the session agents hash table by domain type and return
 239  * the object if found else NULL.
 240  *
 241  * RCU read side lock must be acquired before calling and only released
 242  * once the agent is no longer in scope or being used.
 243  */
 244 struct agent *trace_ust_find_agent(struct ltt_ust_session *session,
 245                 enum lttng_domain_type domain_type)
 246 {
 247         struct agent *agt = NULL;
 248         struct lttng_ht_node_u64 *node;
 249         struct lttng_ht_iter iter;
 250         uint64_t key;
 251
 252         assert(session);
 253
 254         DBG3("Trace ust agent lookup for domain %d", domain_type);
 255
 256         key = domain_type;
 257
 258         lttng_ht_lookup(session->agents, &key, &iter);
 259         node = lttng_ht_iter_get_node_u64(&iter);
 260         if (!node) {
 261                 goto end;
 262         }
 263         agt = caa_container_of(node, struct agent, node);
 264
 265 end:
 266         return agt;
 267 }
 268
 269 /*
 270  * Allocate and initialize a ust session data structure.
 271  *
 272  * Return pointer to structure or NULL.
 273  */
 274 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 275 {
 276         struct ltt_ust_session *lus;
 277
 278         /* Allocate a new ltt ust session */
 279         lus = zmalloc(sizeof(struct ltt_ust_session));
 280         if (lus == NULL) {
 281                 PERROR("create ust session zmalloc");
 282                 goto error;
 283         }
 284
 285         /* Init data structure */
 286         lus->id = session_id;
 287         lus->active = 0;
 288
 289         /* Set default metadata channel attribute. */
 290         lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 291         lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
 292         lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 293         lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 294         lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 295         lus->metadata_attr.output = LTTNG_UST_MMAP;
 296
 297         /*
 298          * Default buffer type. This can be changed through an enable channel
 299          * requesting a different type. Note that this can only be changed once
 300          * during the session lifetime which is at the first enable channel and
 301          * only before start. The flag buffer_type_changed indicates the status.
 302          */
 303         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 304         /* Once set to 1, the buffer_type is immutable for the session. */
 305         lus->buffer_type_changed = 0;
 306         /* Init it in case it get used after allocation. */
 307         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 308
 309         /* Alloc UST global domain channels' HT */
 310         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 311         /* Alloc agent hash table. */
 312         lus->agents = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
 313
 314         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 315         if (lus->consumer == NULL) {
 316                 goto error_consumer;
 317         }
 318
 319         DBG2("UST trace session create successful");
 320
 321         return lus;
 322
 323 error_consumer:
 324         ht_cleanup_push(lus->domain_global.channels);
 325         ht_cleanup_push(lus->agents);
 326         free(lus);
 327 error:
 328         return NULL;
 329 }
 330
 331 /*
 332  * Allocate and initialize a ust channel data structure.
 333  *
 334  * Return pointer to structure or NULL.
 335  */
 336 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 337                 enum lttng_domain_type domain)
 338 {
 339         struct ltt_ust_channel *luc;
 340
 341         assert(chan);
 342
 343         luc = zmalloc(sizeof(struct ltt_ust_channel));
 344         if (luc == NULL) {
 345                 PERROR("ltt_ust_channel zmalloc");
 346                 goto error;
 347         }
 348
 349         luc->domain = domain;
 350
 351         /* Copy UST channel attributes */
 352         luc->attr.overwrite = chan->attr.overwrite;
 353         luc->attr.subbuf_size = chan->attr.subbuf_size;
 354         luc->attr.num_subbuf = chan->attr.num_subbuf;
 355         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 356         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 357         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 358
 359         /* Translate to UST output enum */
 360         switch (luc->attr.output) {
 361         default:
 362                 luc->attr.output = LTTNG_UST_MMAP;
 363                 break;
 364         }
 365
 366         /*
 367          * If we receive an empty string for channel name, it means the
 368          * default channel name is requested.
 369          */
 370         if (chan->name[0] == '\0') {
 371                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 372         } else {
 373                 /* Copy channel name */
 374                 strncpy(luc->name, chan->name, sizeof(luc->name));
 375         }
 376         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 377
 378         /* Init node */
 379         lttng_ht_node_init_str(&luc->node, luc->name);
 380         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 381
 382         /* Alloc hash tables */
 383         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 384         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 385
 386         /* On-disk circular buffer parameters */
 387         luc->tracefile_size = chan->attr.tracefile_size;
 388         luc->tracefile_count = chan->attr.tracefile_count;
 389
 390         DBG2("Trace UST channel %s created", luc->name);
 391
 392 error:
 393         return luc;
 394 }
 395
 396 /*
 397  * Validates an exclusion list.
 398  *
 399  * Returns 0 if valid, negative value if invalid.
 400  */
 401 static int validate_exclusion(struct lttng_event_exclusion *exclusion)
 402 {
 403         size_t i;
 404         int ret = 0;
 405
 406         assert(exclusion);
 407
 408         for (i = 0; i < exclusion->count; ++i) {
 409                 size_t j;
 410                 const char *name_a =
 411                         LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
 412
 413                 for (j = 0; j < i; ++j) {
 414                         const char *name_b =
 415                                 LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, j);
 416
 417                         if (!strncmp(name_a, name_b, LTTNG_SYMBOL_NAME_LEN)) {
 418                                 /* Match! */
 419                                 ret = -1;
 420                                 goto end;
 421                         }
 422                 }
 423         }
 424
 425 end:
 426         return ret;
 427 }
 428
 429 /*
 430  * Allocate and initialize a ust event. Set name and event type.
 431  * We own filter_expression, filter, and exclusion.
 432  *
 433  * Return pointer to structure or NULL.
 434  */
 435 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 436                 char *filter_expression,
 437                 struct lttng_filter_bytecode *filter,
 438                 struct lttng_event_exclusion *exclusion,
 439                 bool internal_event)
 440 {
 441         struct ltt_ust_event *lue;
 442
 443         assert(ev);
 444
 445         if (exclusion && validate_exclusion(exclusion)) {
 446                 goto error;
 447         }
 448
 449         lue = zmalloc(sizeof(struct ltt_ust_event));
 450         if (lue == NULL) {
 451                 PERROR("ust event zmalloc");
 452                 goto error;
 453         }
 454
 455         lue->internal = internal_event;
 456
 457         switch (ev->type) {
 458         case LTTNG_EVENT_PROBE:
 459                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 460                 break;
 461         case LTTNG_EVENT_FUNCTION:
 462                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 463                 break;
 464         case LTTNG_EVENT_FUNCTION_ENTRY:
 465                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 466                 break;
 467         case LTTNG_EVENT_TRACEPOINT:
 468                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 469                 break;
 470         default:
 471                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 472                 goto error_free_event;
 473         }
 474
 475         /* Copy event name */
 476         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 477         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 478
 479         switch (ev->loglevel_type) {
 480         case LTTNG_EVENT_LOGLEVEL_ALL:
 481                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 482                 lue->attr.loglevel = -1;        /* Force to -1 */
 483                 break;
 484         case LTTNG_EVENT_LOGLEVEL_RANGE:
 485                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 486                 lue->attr.loglevel = ev->loglevel;
 487                 break;
 488         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 489                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 490                 lue->attr.loglevel = ev->loglevel;
 491                 break;
 492         default:
 493                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 494                 goto error_free_event;
 495         }
 496
 497         /* Same layout. */
 498         lue->filter_expression = filter_expression;
 499         lue->filter = filter;
 500         lue->exclusion = exclusion;
 501
 502         /* Init node */
 503         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 504
 505         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 506                 lue->attr.name, lue->attr.loglevel_type,
 507                 lue->attr.loglevel);
 508
 509         return lue;
 510
 511 error_free_event:
 512         free(lue);
 513 error:
 514         free(filter_expression);
 515         free(filter);
 516         free(exclusion);
 517         return NULL;
 518 }
 519
 520 static
 521 int trace_ust_context_type_event_to_ust(
 522                 enum lttng_event_context_type type)
 523 {
 524         int utype;
 525
 526         switch (type) {
 527         case LTTNG_EVENT_CONTEXT_VTID:
 528                 utype = LTTNG_UST_CONTEXT_VTID;
 529                 break;
 530         case LTTNG_EVENT_CONTEXT_VPID:
 531                 utype = LTTNG_UST_CONTEXT_VPID;
 532                 break;
 533         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 534                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 535                 break;
 536         case LTTNG_EVENT_CONTEXT_PROCNAME:
 537                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 538                 break;
 539         case LTTNG_EVENT_CONTEXT_IP:
 540                 utype = LTTNG_UST_CONTEXT_IP;
 541                 break;
 542         case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
 543                 if (!ustctl_has_perf_counters()) {
 544                         utype = -1;
 545                         WARN("Perf counters not implemented in UST");
 546                 } else {
 547                         utype = LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER;
 548                 }
 549                 break;
 550         case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
 551                 utype = LTTNG_UST_CONTEXT_APP_CONTEXT;
 552                 break;
 553         default:
 554                 utype = -1;
 555                 break;
 556         }
 557         return utype;
 558 }
 559
 560 /*
 561  * Return 1 if contexts match, 0 otherwise.
 562  */
 563 int trace_ust_match_context(struct ltt_ust_context *uctx,
 564                 struct lttng_event_context *ctx)
 565 {
 566         int utype;
 567
 568         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 569         if (utype < 0) {
 570                 return 0;
 571         }
 572         if (uctx->ctx.ctx != utype) {
 573                 return 0;
 574         }
 575         switch (utype) {
 576         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 577                 if (uctx->ctx.u.perf_counter.type
 578                                 != ctx->u.perf_counter.type) {
 579                         return 0;
 580                 }
 581                 if (uctx->ctx.u.perf_counter.config
 582                                 != ctx->u.perf_counter.config) {
 583                         return 0;
 584                 }
 585                 if (strncmp(uctx->ctx.u.perf_counter.name,
 586                                 ctx->u.perf_counter.name,
 587                                 LTTNG_UST_SYM_NAME_LEN)) {
 588                         return 0;
 589                 }
 590                 break;
 591         default:
 592                 break;
 593
 594         }
 595         return 1;
 596 }
 597
 598 /*
 599  * Allocate and initialize an UST context.
 600  *
 601  * Return pointer to structure or NULL.
 602  */
 603 struct ltt_ust_context *trace_ust_create_context(
 604                 struct lttng_event_context *ctx)
 605 {
 606         struct ltt_ust_context *uctx = NULL;
 607         int utype;
 608
 609         assert(ctx);
 610
 611         utype = trace_ust_context_type_event_to_ust(ctx->ctx);
 612         if (utype < 0) {
 613                 ERR("Invalid UST context");
 614                 goto end;
 615         }
 616
 617         uctx = zmalloc(sizeof(struct ltt_ust_context));
 618         if (!uctx) {
 619                 PERROR("zmalloc ltt_ust_context");
 620                 goto end;
 621         }
 622
 623         uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
 624         switch (utype) {
 625         case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 626                 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 627                 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 628                 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 629                                 LTTNG_UST_SYM_NAME_LEN);
 630                 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 631                 break;
 632         case LTTNG_UST_CONTEXT_APP_CONTEXT:
 633         {
 634                 char *provider_name = NULL, *ctx_name = NULL;
 635
 636                 provider_name = strdup(ctx->u.app_ctx.provider_name);
 637                 if (!provider_name) {
 638                         goto error;
 639                 }
 640                 uctx->ctx.u.app_ctx.provider_name = provider_name;
 641
 642                 ctx_name = strdup(ctx->u.app_ctx.ctx_name);
 643                 if (!ctx_name) {
 644                         goto error;
 645                 }
 646                 uctx->ctx.u.app_ctx.ctx_name = ctx_name;
 647                 break;
 648         }
 649         default:
 650                 break;
 651         }
 652         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 653 end:
 654         return uctx;
 655 error:
 656         trace_ust_destroy_context(uctx);
 657         return NULL;
 658 }
 659
 660 static
 661 void destroy_pid_tracker_node_rcu(struct rcu_head *head)
 662 {
 663         struct ust_pid_tracker_node *tracker_node =
 664                 caa_container_of(head, struct ust_pid_tracker_node, node.head);
 665         free(tracker_node);
 666 }
 667
 668 static
 669 void destroy_pid_tracker_node(struct ust_pid_tracker_node *tracker_node)
 670 {
 671
 672         call_rcu(&tracker_node->node.head, destroy_pid_tracker_node_rcu);
 673 }
 674
 675 static
 676 int init_pid_tracker(struct ust_pid_tracker *pid_tracker)
 677 {
 678         int ret = 0;
 679
 680         pid_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 681         if (!pid_tracker->ht) {
 682                 ret = -1;
 683                 goto end;
 684         }
 685
 686 end:
 687         return ret;
 688 }
 689
 690 /*
 691  * Teardown pid tracker content, but don't free pid_tracker object.
 692  */
 693 static
 694 void fini_pid_tracker(struct ust_pid_tracker *pid_tracker)
 695 {
 696         struct ust_pid_tracker_node *tracker_node;
 697         struct lttng_ht_iter iter;
 698
 699         if (!pid_tracker->ht) {
 700                 return;
 701         }
 702         rcu_read_lock();
 703         cds_lfht_for_each_entry(pid_tracker->ht->ht,
 704                         &iter.iter, tracker_node, node.node) {
 705                 int ret = lttng_ht_del(pid_tracker->ht, &iter);
 706
 707                 assert(!ret);
 708                 destroy_pid_tracker_node(tracker_node);
 709         }
 710         rcu_read_unlock();
 711         ht_cleanup_push(pid_tracker->ht);
 712         pid_tracker->ht = NULL;
 713 }
 714
 715 static
 716 struct ust_pid_tracker_node *pid_tracker_lookup(
 717                 struct ust_pid_tracker *pid_tracker, int pid,
 718                 struct lttng_ht_iter *iter)
 719 {
 720         unsigned long _pid = (unsigned long) pid;
 721         struct lttng_ht_node_ulong *node;
 722
 723         lttng_ht_lookup(pid_tracker->ht, (void *) _pid, iter);
 724         node = lttng_ht_iter_get_node_ulong(iter);
 725         if (node) {
 726                 return caa_container_of(node, struct ust_pid_tracker_node,
 727                         node);
 728         } else {
 729                 return NULL;
 730         }
 731 }
 732
 733 static
 734 int pid_tracker_add_pid(struct ust_pid_tracker *pid_tracker, int pid)
 735 {
 736         int retval = LTTNG_OK;
 737         struct ust_pid_tracker_node *tracker_node;
 738         struct lttng_ht_iter iter;
 739
 740         if (pid < 0) {
 741                 retval = LTTNG_ERR_INVALID;
 742                 goto end;
 743         }
 744         tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
 745         if (tracker_node) {
 746                 /* Already exists. */
 747                 retval = LTTNG_ERR_PID_TRACKED;
 748                 goto end;
 749         }
 750         tracker_node = zmalloc(sizeof(*tracker_node));
 751         if (!tracker_node) {
 752                 retval = LTTNG_ERR_NOMEM;
 753                 goto end;
 754         }
 755         lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) pid);
 756         lttng_ht_add_unique_ulong(pid_tracker->ht, &tracker_node->node);
 757 end:
 758         return retval;
 759 }
 760
 761 static
 762 int pid_tracker_del_pid(struct ust_pid_tracker *pid_tracker, int pid)
 763 {
 764         int retval = LTTNG_OK, ret;
 765         struct ust_pid_tracker_node *tracker_node;
 766         struct lttng_ht_iter iter;
 767
 768         if (pid < 0) {
 769                 retval = LTTNG_ERR_INVALID;
 770                 goto end;
 771         }
 772         tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
 773         if (!tracker_node) {
 774                 /* Not found */
 775                 retval = LTTNG_ERR_PID_NOT_TRACKED;
 776                 goto end;
 777         }
 778         ret = lttng_ht_del(pid_tracker->ht, &iter);
 779         assert(!ret);
 780
 781         destroy_pid_tracker_node(tracker_node);
 782 end:
 783         return retval;
 784 }
 785
 786 /*
 787  * The session lock is held when calling this function.
 788  */
 789 int trace_ust_pid_tracker_lookup(struct ltt_ust_session *session, int pid)
 790 {
 791         struct lttng_ht_iter iter;
 792
 793         if (!session->pid_tracker.ht) {
 794                 return 1;
 795         }
 796         if (pid_tracker_lookup(&session->pid_tracker, pid, &iter)) {
 797                 return 1;
 798         }
 799         return 0;
 800 }
 801
 802 /*
 803  * Called with the session lock held.
 804  */
 805 int trace_ust_track_pid(struct ltt_ust_session *session, int pid)
 806 {
 807         int retval = LTTNG_OK;
 808
 809         if (pid == -1) {
 810                 /* Track all pids: destroy tracker if exists. */
 811                 if (session->pid_tracker.ht) {
 812                         fini_pid_tracker(&session->pid_tracker);
 813                         /* Ensure all apps have session. */
 814                         ust_app_global_update_all(session);
 815                 }
 816         } else {
 817                 int ret;
 818
 819                 if (!session->pid_tracker.ht) {
 820                         /* Create tracker. */
 821                         if (init_pid_tracker(&session->pid_tracker)) {
 822                                 ERR("Error initializing PID tracker");
 823                                 retval = LTTNG_ERR_NOMEM;
 824                                 goto end;
 825                         }
 826                         ret = pid_tracker_add_pid(&session->pid_tracker, pid);
 827                         if (ret != LTTNG_OK) {
 828                                 retval = ret;
 829                                 fini_pid_tracker(&session->pid_tracker);
 830                                 goto end;
 831                         }
 832                         /* Remove all apps from session except pid. */
 833                         ust_app_global_update_all(session);
 834                 } else {
 835                         struct ust_app *app;
 836
 837                         ret = pid_tracker_add_pid(&session->pid_tracker, pid);
 838                         if (ret != LTTNG_OK) {
 839                                 retval = ret;
 840                                 goto end;
 841                         }
 842                         /* Add session to application */
 843                         app = ust_app_find_by_pid(pid);
 844                         if (app) {
 845                                 ust_app_global_update(session, app);
 846                         }
 847                 }
 848         }
 849 end:
 850         return retval;
 851 }
 852
 853 /*
 854  * Called with the session lock held.
 855  */
 856 int trace_ust_untrack_pid(struct ltt_ust_session *session, int pid)
 857 {
 858         int retval = LTTNG_OK;
 859
 860         if (pid == -1) {
 861                 /* Create empty tracker, replace old tracker. */
 862                 struct ust_pid_tracker tmp_tracker;
 863
 864                 tmp_tracker = session->pid_tracker;
 865                 if (init_pid_tracker(&session->pid_tracker)) {
 866                         ERR("Error initializing PID tracker");
 867                         retval = LTTNG_ERR_NOMEM;
 868                         /* Rollback operation. */
 869                         session->pid_tracker = tmp_tracker;
 870                         goto end;
 871                 }
 872                 fini_pid_tracker(&tmp_tracker);
 873
 874                 /* Remove session from all applications */
 875                 ust_app_global_update_all(session);
 876         } else {
 877                 int ret;
 878                 struct ust_app *app;
 879
 880                 if (!session->pid_tracker.ht) {
 881                         /* No PID being tracked. */
 882                         retval = LTTNG_ERR_PID_NOT_TRACKED;
 883                         goto end;
 884                 }
 885                 /* Remove PID from tracker */
 886                 ret = pid_tracker_del_pid(&session->pid_tracker, pid);
 887                 if (ret != LTTNG_OK) {
 888                         retval = ret;
 889                         goto end;
 890                 }
 891                 /* Remove session from application. */
 892                 app = ust_app_find_by_pid(pid);
 893                 if (app) {
 894                         ust_app_global_update(session, app);
 895                 }
 896         }
 897 end:
 898         return retval;
 899 }
 900
 901 /*
 902  * Called with session lock held.
 903  */
 904 ssize_t trace_ust_list_tracker_pids(struct ltt_ust_session *session,
 905                 int32_t **_pids)
 906 {
 907         struct ust_pid_tracker_node *tracker_node;
 908         struct lttng_ht_iter iter;
 909         unsigned long count, i = 0;
 910         long approx[2];
 911         int32_t *pids;
 912         int ret = 0;
 913
 914         if (!session->pid_tracker.ht) {
 915                 /* Tracker disabled. Set first entry to -1. */
 916                 pids = zmalloc(sizeof(*pids));
 917                 if (!pids) {
 918                         ret = -1;
 919                         goto end;
 920                 }
 921                 pids[0] = -1;
 922                 *_pids = pids;
 923                 return 1;
 924         }
 925
 926         rcu_read_lock();
 927         cds_lfht_count_nodes(session->pid_tracker.ht->ht,
 928                 &approx[0], &count, &approx[1]);
 929         pids = zmalloc(sizeof(*pids) * count);
 930         if (!pids) {
 931                 ret = -1;
 932                 goto end;
 933         }
 934         cds_lfht_for_each_entry(session->pid_tracker.ht->ht,
 935                         &iter.iter, tracker_node, node.node) {
 936                 pids[i++] = tracker_node->node.key;
 937         }
 938         *_pids = pids;
 939         ret = count;
 940 end:
 941         rcu_read_unlock();
 942         return ret;
 943 }
 944
 945 /*
 946  * RCU safe free context structure.
 947  */
 948 static void destroy_context_rcu(struct rcu_head *head)
 949 {
 950         struct lttng_ht_node_ulong *node =
 951                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 952         struct ltt_ust_context *ctx =
 953                 caa_container_of(node, struct ltt_ust_context, node);
 954
 955         trace_ust_destroy_context(ctx);
 956 }
 957
 958 /*
 959  * Cleanup UST context hash table.
 960  */
 961 static void destroy_contexts(struct lttng_ht *ht)
 962 {
 963         int ret;
 964         struct lttng_ht_node_ulong *node;
 965         struct lttng_ht_iter iter;
 966         struct ltt_ust_context *ctx;
 967
 968         assert(ht);
 969
 970         rcu_read_lock();
 971         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 972                 /* Remove from ordered list. */
 973                 ctx = caa_container_of(node, struct ltt_ust_context, node);
 974                 cds_list_del(&ctx->list);
 975                 /* Remove from channel's hash table. */
 976                 ret = lttng_ht_del(ht, &iter);
 977                 if (!ret) {
 978                         call_rcu(&node->head, destroy_context_rcu);
 979                 }
 980         }
 981         rcu_read_unlock();
 982
 983         ht_cleanup_push(ht);
 984 }
 985
 986 /*
 987  * Cleanup ust event structure.
 988  */
 989 void trace_ust_destroy_event(struct ltt_ust_event *event)
 990 {
 991         assert(event);
 992
 993         DBG2("Trace destroy UST event %s", event->attr.name);
 994         free(event->filter_expression);
 995         free(event->filter);
 996         free(event->exclusion);
 997         free(event);
 998 }
 999
1000 /*
1001  * Cleanup ust context structure.
1002  */
1003 void trace_ust_destroy_context(struct ltt_ust_context *ctx)
1004 {
1005         assert(ctx);
1006
1007         if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1008                 free(ctx->ctx.u.app_ctx.provider_name);
1009                 free(ctx->ctx.u.app_ctx.ctx_name);
1010         }
1011         free(ctx);
1012 }
1013
1014 /*
1015  * URCU intermediate call to complete destroy event.
1016  */
1017 static void destroy_event_rcu(struct rcu_head *head)
1018 {
1019         struct lttng_ht_node_str *node =
1020                 caa_container_of(head, struct lttng_ht_node_str, head);
1021         struct ltt_ust_event *event =
1022                 caa_container_of(node, struct ltt_ust_event, node);
1023
1024         trace_ust_destroy_event(event);
1025 }
1026
1027 /*
1028  * Cleanup UST events hashtable.
1029  */
1030 static void destroy_events(struct lttng_ht *events)
1031 {
1032         int ret;
1033         struct lttng_ht_node_str *node;
1034         struct lttng_ht_iter iter;
1035
1036         assert(events);
1037
1038         rcu_read_lock();
1039         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
1040                 ret = lttng_ht_del(events, &iter);
1041                 assert(!ret);
1042                 call_rcu(&node->head, destroy_event_rcu);
1043         }
1044         rcu_read_unlock();
1045
1046         ht_cleanup_push(events);
1047 }
1048
1049 /*
1050  * Cleanup ust channel structure.
1051  *
1052  * Should _NOT_ be called with RCU read lock held.
1053  */
1054 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1055 {
1056         assert(channel);
1057
1058         DBG2("Trace destroy UST channel %s", channel->name);
1059
1060         free(channel);
1061 }
1062
1063 /*
1064  * URCU intermediate call to complete destroy channel.
1065  */
1066 static void destroy_channel_rcu(struct rcu_head *head)
1067 {
1068         struct lttng_ht_node_str *node =
1069                 caa_container_of(head, struct lttng_ht_node_str, head);
1070         struct ltt_ust_channel *channel =
1071                 caa_container_of(node, struct ltt_ust_channel, node);
1072
1073         _trace_ust_destroy_channel(channel);
1074 }
1075
1076 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
1077 {
1078         /* Destroying all events of the channel */
1079         destroy_events(channel->events);
1080         /* Destroying all context of the channel */
1081         destroy_contexts(channel->ctx);
1082
1083         call_rcu(&channel->node.head, destroy_channel_rcu);
1084 }
1085
1086 /*
1087  * Remove an UST channel from a channel HT.
1088  */
1089 void trace_ust_delete_channel(struct lttng_ht *ht,
1090                 struct ltt_ust_channel *channel)
1091 {
1092         int ret;
1093         struct lttng_ht_iter iter;
1094
1095         assert(ht);
1096         assert(channel);
1097
1098         iter.iter.node = &channel->node.node;
1099         ret = lttng_ht_del(ht, &iter);
1100         assert(!ret);
1101 }
1102
1103 /*
1104  * Iterate over a hash table containing channels and cleanup safely.
1105  */
1106 static void destroy_channels(struct lttng_ht *channels)
1107 {
1108         struct lttng_ht_node_str *node;
1109         struct lttng_ht_iter iter;
1110
1111         assert(channels);
1112
1113         rcu_read_lock();
1114         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1115                 struct ltt_ust_channel *chan =
1116                         caa_container_of(node, struct ltt_ust_channel, node);
1117
1118                 trace_ust_delete_channel(channels, chan);
1119                 trace_ust_destroy_channel(chan);
1120         }
1121         rcu_read_unlock();
1122
1123         ht_cleanup_push(channels);
1124 }
1125
1126 /*
1127  * Cleanup UST global domain.
1128  */
1129 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1130 {
1131         assert(dom);
1132
1133         destroy_channels(dom->channels);
1134 }
1135
1136 /*
1137  * Cleanup ust session structure
1138  *
1139  * Should *NOT* be called with RCU read-side lock held.
1140  */
1141 void trace_ust_destroy_session(struct ltt_ust_session *session)
1142 {
1143         struct agent *agt;
1144         struct buffer_reg_uid *reg, *sreg;
1145         struct lttng_ht_iter iter;
1146
1147         assert(session);
1148
1149         DBG2("Trace UST destroy session %" PRIu64, session->id);
1150
1151         /* Cleaning up UST domain */
1152         destroy_domain_global(&session->domain_global);
1153
1154         rcu_read_lock();
1155         cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1156                 int ret = lttng_ht_del(session->agents, &iter);
1157
1158                 assert(!ret);
1159                 agent_destroy(agt);
1160         }
1161         rcu_read_unlock();
1162
1163         ht_cleanup_push(session->agents);
1164
1165         /* Cleanup UID buffer registry object(s). */
1166         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1167                         lnode) {
1168                 cds_list_del(&reg->lnode);
1169                 buffer_reg_uid_remove(reg);
1170                 buffer_reg_uid_destroy(reg, session->consumer);
1171         }
1172
1173         consumer_output_put(session->consumer);
1174
1175         fini_pid_tracker(&session->pid_tracker);
1176
1177         free(session);
1178 }