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 _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 #include <common/common.h>
  25 #include <common/defaults.h>
  26
  27 #include "trace-ust.h"
  28
  29 /*
  30  * Match function for the events hash table lookup.
  31  *
  32  * Matches by name only. Used by the disable command.
  33  */
  34 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  35                 const void *_key)
  36 {
  37         struct ltt_ust_event *event;
  38         const char *name;
  39
  40         assert(node);
  41         assert(_key);
  42
  43         event = caa_container_of(node, struct ltt_ust_event, node.node);
  44         name = _key;
  45
  46         /* Event name */
  47         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  48                 goto no_match;
  49         }
  50
  51         /* Match */
  52         return 1;
  53
  54 no_match:
  55         return 0;
  56 }
  57
  58 /*
  59  * Match function for the hash table lookup.
  60  *
  61  * It matches an ust event based on three attributes which are the event name,
  62  * the filter bytecode and the loglevel.
  63  */
  64 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  65 {
  66         struct ltt_ust_event *event;
  67         const struct ltt_ust_ht_key *key;
  68
  69         assert(node);
  70         assert(_key);
  71
  72         event = caa_container_of(node, struct ltt_ust_event, node.node);
  73         key = _key;
  74
  75         /* Match the 3 elements of the key: name, filter and loglevel. */
  76
  77         /* Event name */
  78         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  79                 goto no_match;
  80         }
  81
  82         /* Event loglevel. */
  83         if (event->attr.loglevel != key->loglevel) {
  84                 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
  85                                 && key->loglevel == 0 && event->attr.loglevel == -1) {
  86                         /*
  87                          * Match is accepted. This is because on event creation, the
  88                          * loglevel is set to -1 if the event loglevel type is ALL so 0 and
  89                          * -1 are accepted for this loglevel type since 0 is the one set by
  90                          * the API when receiving an enable event.
  91                          */
  92                 } else {
  93                         goto no_match;
  94                 }
  95         }
  96
  97         /* Only one of the filters is NULL, fail. */
  98         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
  99                 goto no_match;
 100         }
 101
 102         if (key->filter && event->filter) {
 103                 /* Both filters exists, check length followed by the bytecode. */
 104                 if (event->filter->len != key->filter->len ||
 105                                 memcmp(event->filter->data, key->filter->data,
 106                                         event->filter->len) != 0) {
 107                         goto no_match;
 108                 }
 109         }
 110
 111         /* Match. */
 112         return 1;
 113
 114 no_match:
 115         return 0;
 116 }
 117
 118 /*
 119  * Find the channel in the hashtable.
 120  */
 121 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 122                 char *name)
 123 {
 124         struct lttng_ht_node_str *node;
 125         struct lttng_ht_iter iter;
 126
 127         rcu_read_lock();
 128         lttng_ht_lookup(ht, (void *)name, &iter);
 129         node = lttng_ht_iter_get_node_str(&iter);
 130         if (node == NULL) {
 131                 rcu_read_unlock();
 132                 goto error;
 133         }
 134         rcu_read_unlock();
 135
 136         DBG2("Trace UST channel %s found by name", name);
 137
 138         return caa_container_of(node, struct ltt_ust_channel, node);
 139
 140 error:
 141         DBG2("Trace UST channel %s not found by name", name);
 142         return NULL;
 143 }
 144
 145 /*
 146  * Find the event in the hashtable.
 147  */
 148 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 149                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 150 {
 151         struct lttng_ht_node_str *node;
 152         struct lttng_ht_iter iter;
 153         struct ltt_ust_ht_key key;
 154
 155         assert(name);
 156         assert(ht);
 157
 158         key.name = name;
 159         key.filter = filter;
 160         key.loglevel = loglevel;
 161
 162         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 163                         trace_ust_ht_match_event, &key, &iter.iter);
 164         node = lttng_ht_iter_get_node_str(&iter);
 165         if (node == NULL) {
 166                 goto error;
 167         }
 168
 169         DBG2("Trace UST event %s found", key.name);
 170
 171         return caa_container_of(node, struct ltt_ust_event, node);
 172
 173 error:
 174         DBG2("Trace UST event %s NOT found", key.name);
 175         return NULL;
 176 }
 177
 178 /*
 179  * Allocate and initialize a ust session data structure.
 180  *
 181  * Return pointer to structure or NULL.
 182  */
 183 struct ltt_ust_session *trace_ust_create_session(char *path,
 184                 unsigned int session_id, struct lttng_domain *domain)
 185 {
 186         struct ltt_ust_session *lus;
 187
 188         /* Allocate a new ltt ust session */
 189         lus = zmalloc(sizeof(struct ltt_ust_session));
 190         if (lus == NULL) {
 191                 PERROR("create ust session zmalloc");
 192                 goto error;
 193         }
 194
 195         /* Init data structure */
 196         lus->id = session_id;
 197         lus->start_trace = 0;
 198
 199         /* Alloc UST domain hash tables */
 200         lus->domain_pid = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 201         lus->domain_exec = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 202
 203         /* Alloc UST global domain channels' HT */
 204         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 205
 206         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 207         if (lus->consumer == NULL) {
 208                 goto error_consumer;
 209         }
 210
 211         /*
 212          * The tmp_consumer stays NULL until a set_consumer_uri command is
 213          * executed. At this point, the consumer should be nullify until an
 214          * enable_consumer command. This assignment is symbolic since we've zmalloc
 215          * the struct.
 216          */
 217         lus->tmp_consumer = NULL;
 218
 219         /* Use the default consumer output which is the tracing session path. */
 220         if (path && strlen(path) > 0) {
 221                 int ret;
 222
 223                 ret = snprintf(lus->consumer->dst.trace_path, PATH_MAX,
 224                                 "%s" DEFAULT_UST_TRACE_DIR, path);
 225                 if (ret < 0) {
 226                         PERROR("snprintf UST consumer trace path");
 227                         goto error_path;
 228                 }
 229
 230                 /* Set session path */
 231                 ret = snprintf(lus->pathname, PATH_MAX, "%s" DEFAULT_UST_TRACE_DIR,
 232                                 path);
 233                 if (ret < 0) {
 234                         PERROR("snprintf kernel traces path");
 235                         goto error_path;
 236                 }
 237         }
 238
 239         DBG2("UST trace session create successful");
 240
 241         return lus;
 242
 243 error_path:
 244         consumer_destroy_output(lus->consumer);
 245 error_consumer:
 246         lttng_ht_destroy(lus->domain_global.channels);
 247         lttng_ht_destroy(lus->domain_exec);
 248         lttng_ht_destroy(lus->domain_pid);
 249         free(lus);
 250 error:
 251         return NULL;
 252 }
 253
 254 /*
 255  * Allocate and initialize a ust channel data structure.
 256  *
 257  * Return pointer to structure or NULL.
 258  */
 259 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 260                 char *path)
 261 {
 262         int ret;
 263         struct ltt_ust_channel *luc;
 264
 265         luc = zmalloc(sizeof(struct ltt_ust_channel));
 266         if (luc == NULL) {
 267                 PERROR("ltt_ust_channel zmalloc");
 268                 goto error;
 269         }
 270
 271         /* Copy UST channel attributes */
 272         luc->attr.overwrite = chan->attr.overwrite;
 273         luc->attr.subbuf_size = chan->attr.subbuf_size;
 274         luc->attr.num_subbuf = chan->attr.num_subbuf;
 275         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 276         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 277         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 278
 279         /* Translate to UST output enum */
 280         switch (luc->attr.output) {
 281         default:
 282                 luc->attr.output = LTTNG_UST_MMAP;
 283                 break;
 284         }
 285
 286         /* Copy channel name */
 287         strncpy(luc->name, chan->name, sizeof(luc->name));
 288         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 289
 290         /* Init node */
 291         lttng_ht_node_init_str(&luc->node, luc->name);
 292         /* Alloc hash tables */
 293         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 294         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 295
 296         /* Set trace output path */
 297         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 298         if (ret < 0) {
 299                 PERROR("asprintf ust create channel");
 300                 goto error_free_channel;
 301         }
 302
 303         DBG2("Trace UST channel %s created", luc->name);
 304
 305         return luc;
 306
 307 error_free_channel:
 308         lttng_ht_destroy(luc->ctx);
 309         lttng_ht_destroy(luc->events);
 310         free(luc);
 311 error:
 312         return NULL;
 313 }
 314
 315 /*
 316  * Allocate and initialize a ust event. Set name and event type.
 317  *
 318  * Return pointer to structure or NULL.
 319  */
 320 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 321                 struct lttng_filter_bytecode *filter)
 322 {
 323         struct ltt_ust_event *lue;
 324
 325         lue = zmalloc(sizeof(struct ltt_ust_event));
 326         if (lue == NULL) {
 327                 PERROR("ust event zmalloc");
 328                 goto error;
 329         }
 330
 331         switch (ev->type) {
 332         case LTTNG_EVENT_PROBE:
 333                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 334                 break;
 335         case LTTNG_EVENT_FUNCTION:
 336                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 337                 break;
 338         case LTTNG_EVENT_FUNCTION_ENTRY:
 339                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 340                 break;
 341         case LTTNG_EVENT_TRACEPOINT:
 342                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 343                 break;
 344         default:
 345                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 346                 goto error_free_event;
 347         }
 348
 349         /* Copy event name */
 350         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 351         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 352
 353         switch (ev->loglevel_type) {
 354         case LTTNG_EVENT_LOGLEVEL_ALL:
 355                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 356                 lue->attr.loglevel = -1;        /* Force to -1 */
 357                 break;
 358         case LTTNG_EVENT_LOGLEVEL_RANGE:
 359                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 360                 lue->attr.loglevel = ev->loglevel;
 361                 break;
 362         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 363                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 364                 lue->attr.loglevel = ev->loglevel;
 365                 break;
 366         default:
 367                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 368                 goto error_free_event;
 369         }
 370
 371         /* Same layout. */
 372         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 373
 374         /* Init node */
 375         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 376
 377         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 378                 lue->attr.name, lue->attr.loglevel_type,
 379                 lue->attr.loglevel);
 380
 381         return lue;
 382
 383 error_free_event:
 384         free(lue);
 385 error:
 386         return NULL;
 387 }
 388
 389 /*
 390  * Allocate and initialize a ust metadata.
 391  *
 392  * Return pointer to structure or NULL.
 393  */
 394 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 395 {
 396         int ret;
 397         struct ltt_ust_metadata *lum;
 398
 399         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 400         if (lum == NULL) {
 401                 PERROR("ust metadata zmalloc");
 402                 goto error;
 403         }
 404
 405         /* Set default attributes */
 406         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 407         lum->attr.subbuf_size = default_get_metadata_subbuf_size();
 408         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 409         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 410         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 411         lum->attr.output = LTTNG_UST_MMAP;
 412
 413         lum->handle = -1;
 414         /* Set metadata trace path */
 415         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 416         if (ret < 0) {
 417                 PERROR("asprintf ust metadata");
 418                 goto error_free_metadata;
 419         }
 420
 421         return lum;
 422
 423 error_free_metadata:
 424         free(lum);
 425 error:
 426         return NULL;
 427 }
 428
 429 /*
 430  * Allocate and initialize an UST context.
 431  *
 432  * Return pointer to structure or NULL.
 433  */
 434 struct ltt_ust_context *trace_ust_create_context(
 435                 struct lttng_event_context *ctx)
 436 {
 437         struct ltt_ust_context *uctx;
 438         enum lttng_ust_context_type utype;
 439
 440         switch (ctx->ctx) {
 441         case LTTNG_EVENT_CONTEXT_VTID:
 442                 utype = LTTNG_UST_CONTEXT_VTID;
 443                 break;
 444         case LTTNG_EVENT_CONTEXT_VPID:
 445                 utype = LTTNG_UST_CONTEXT_VPID;
 446                 break;
 447         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 448                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 449                 break;
 450         case LTTNG_EVENT_CONTEXT_PROCNAME:
 451                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 452                 break;
 453         default:
 454                 ERR("Invalid UST context");
 455                 return NULL;
 456         }
 457
 458         uctx = zmalloc(sizeof(struct ltt_ust_context));
 459         if (uctx == NULL) {
 460                 PERROR("zmalloc ltt_ust_context");
 461                 goto error;
 462         }
 463
 464         uctx->ctx.ctx = utype;
 465         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 466
 467         return uctx;
 468
 469 error:
 470         return NULL;
 471 }
 472
 473 /*
 474  * RCU safe free context structure.
 475  */
 476 static void destroy_context_rcu(struct rcu_head *head)
 477 {
 478         struct lttng_ht_node_ulong *node =
 479                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 480         struct ltt_ust_context *ctx =
 481                 caa_container_of(node, struct ltt_ust_context, node);
 482
 483         free(ctx);
 484 }
 485
 486 /*
 487  * Cleanup UST context hash table.
 488  */
 489 static void destroy_contexts(struct lttng_ht *ht)
 490 {
 491         int ret;
 492         struct lttng_ht_node_ulong *node;
 493         struct lttng_ht_iter iter;
 494
 495         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 496                 ret = lttng_ht_del(ht, &iter);
 497                 if (!ret) {
 498                         call_rcu(&node->head, destroy_context_rcu);
 499                 }
 500         }
 501
 502         lttng_ht_destroy(ht);
 503 }
 504
 505 /*
 506  * Cleanup ust event structure.
 507  */
 508 void trace_ust_destroy_event(struct ltt_ust_event *event)
 509 {
 510         DBG2("Trace destroy UST event %s", event->attr.name);
 511         free(event->filter);
 512         free(event);
 513 }
 514
 515 /*
 516  * URCU intermediate call to complete destroy event.
 517  */
 518 static void destroy_event_rcu(struct rcu_head *head)
 519 {
 520         struct lttng_ht_node_str *node =
 521                 caa_container_of(head, struct lttng_ht_node_str, head);
 522         struct ltt_ust_event *event =
 523                 caa_container_of(node, struct ltt_ust_event, node);
 524
 525         trace_ust_destroy_event(event);
 526 }
 527
 528 /*
 529  * Cleanup UST events hashtable.
 530  */
 531 static void destroy_events(struct lttng_ht *events)
 532 {
 533         int ret;
 534         struct lttng_ht_node_str *node;
 535         struct lttng_ht_iter iter;
 536
 537         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 538                 ret = lttng_ht_del(events, &iter);
 539                 assert(!ret);
 540                 call_rcu(&node->head, destroy_event_rcu);
 541         }
 542
 543         lttng_ht_destroy(events);
 544 }
 545
 546 /*
 547  * Cleanup ust channel structure.
 548  */
 549 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 550 {
 551         DBG2("Trace destroy UST channel %s", channel->name);
 552
 553         rcu_read_lock();
 554
 555         /* Destroying all events of the channel */
 556         destroy_events(channel->events);
 557         /* Destroying all context of the channel */
 558         destroy_contexts(channel->ctx);
 559
 560         free(channel);
 561
 562         rcu_read_unlock();
 563 }
 564
 565 /*
 566  * URCU intermediate call to complete destroy channel.
 567  */
 568 static void destroy_channel_rcu(struct rcu_head *head)
 569 {
 570         struct lttng_ht_node_str *node =
 571                 caa_container_of(head, struct lttng_ht_node_str, head);
 572         struct ltt_ust_channel *channel =
 573                 caa_container_of(node, struct ltt_ust_channel, node);
 574
 575         trace_ust_destroy_channel(channel);
 576 }
 577
 578 /*
 579  * Cleanup ust metadata structure.
 580  */
 581 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 582 {
 583         if (!metadata->handle) {
 584                 return;
 585         }
 586         DBG2("Trace UST destroy metadata %d", metadata->handle);
 587         free(metadata);
 588 }
 589
 590 /*
 591  * Iterate over a hash table containing channels and cleanup safely.
 592  */
 593 static void destroy_channels(struct lttng_ht *channels)
 594 {
 595         int ret;
 596         struct lttng_ht_node_str *node;
 597         struct lttng_ht_iter iter;
 598
 599         rcu_read_lock();
 600
 601         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 602                 ret = lttng_ht_del(channels, &iter);
 603                 assert(!ret);
 604                 call_rcu(&node->head, destroy_channel_rcu);
 605         }
 606
 607         lttng_ht_destroy(channels);
 608
 609         rcu_read_unlock();
 610 }
 611
 612 /*
 613  * Cleanup UST pid domain.
 614  */
 615 static void destroy_domain_pid(struct lttng_ht *ht)
 616 {
 617         int ret;
 618         struct lttng_ht_iter iter;
 619         struct ltt_ust_domain_pid *dpid;
 620
 621         cds_lfht_for_each_entry(ht->ht, &iter.iter, dpid, node.node) {
 622                 ret = lttng_ht_del(ht , &iter);
 623                 assert(!ret);
 624                 destroy_channels(dpid->channels);
 625         }
 626
 627         lttng_ht_destroy(ht);
 628 }
 629
 630 /*
 631  * Cleanup UST exec name domain.
 632  */
 633 static void destroy_domain_exec(struct lttng_ht *ht)
 634 {
 635         int ret;
 636         struct lttng_ht_iter iter;
 637         struct ltt_ust_domain_exec *dexec;
 638
 639         cds_lfht_for_each_entry(ht->ht, &iter.iter, dexec, node.node) {
 640                 ret = lttng_ht_del(ht , &iter);
 641                 assert(!ret);
 642                 destroy_channels(dexec->channels);
 643         }
 644
 645         lttng_ht_destroy(ht);
 646 }
 647
 648 /*
 649  * Cleanup UST global domain.
 650  */
 651 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 652 {
 653         destroy_channels(dom->channels);
 654 }
 655
 656 /*
 657  * Cleanup ust session structure
 658  */
 659 void trace_ust_destroy_session(struct ltt_ust_session *session)
 660 {
 661         /* Extra protection */
 662         if (session == NULL) {
 663                 return;
 664         }
 665
 666         rcu_read_lock();
 667
 668         DBG2("Trace UST destroy session %u", session->id);
 669
 670         /* Cleaning up UST domain */
 671         destroy_domain_global(&session->domain_global);
 672         destroy_domain_pid(session->domain_pid);
 673         destroy_domain_exec(session->domain_exec);
 674
 675         consumer_destroy_output(session->consumer);
 676         consumer_destroy_output(session->tmp_consumer);
 677
 678         free(session);
 679
 680         rcu_read_unlock();
 681 }