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 "buffer-registry.h"
  28 #include "trace-ust.h"
  29
  30 /*
  31  * Match function for the events hash table lookup.
  32  *
  33  * Matches by name only. Used by the disable command.
  34  */
  35 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  36                 const void *_key)
  37 {
  38         struct ltt_ust_event *event;
  39         const char *name;
  40
  41         assert(node);
  42         assert(_key);
  43
  44         event = caa_container_of(node, struct ltt_ust_event, node.node);
  45         name = _key;
  46
  47         /* Event name */
  48         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  49                 goto no_match;
  50         }
  51
  52         /* Match */
  53         return 1;
  54
  55 no_match:
  56         return 0;
  57 }
  58
  59 /*
  60  * Match function for the hash table lookup.
  61  *
  62  * It matches an ust event based on three attributes which are the event name,
  63  * the filter bytecode and the loglevel.
  64  */
  65 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  66 {
  67         struct ltt_ust_event *event;
  68         const struct ltt_ust_ht_key *key;
  69
  70         assert(node);
  71         assert(_key);
  72
  73         event = caa_container_of(node, struct ltt_ust_event, node.node);
  74         key = _key;
  75
  76         /* Match the 3 elements of the key: name, filter and loglevel. */
  77
  78         /* Event name */
  79         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  80                 goto no_match;
  81         }
  82
  83         /* Event loglevel. */
  84         if (event->attr.loglevel != key->loglevel) {
  85                 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
  86                                 && key->loglevel == 0 && event->attr.loglevel == -1) {
  87                         /*
  88                          * Match is accepted. This is because on event creation, the
  89                          * loglevel is set to -1 if the event loglevel type is ALL so 0 and
  90                          * -1 are accepted for this loglevel type since 0 is the one set by
  91                          * the API when receiving an enable event.
  92                          */
  93                 } else {
  94                         goto no_match;
  95                 }
  96         }
  97
  98         /* Only one of the filters is NULL, fail. */
  99         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 100                 goto no_match;
 101         }
 102
 103         if (key->filter && event->filter) {
 104                 /* Both filters exists, check length followed by the bytecode. */
 105                 if (event->filter->len != key->filter->len ||
 106                                 memcmp(event->filter->data, key->filter->data,
 107                                         event->filter->len) != 0) {
 108                         goto no_match;
 109                 }
 110         }
 111
 112         /* Match. */
 113         return 1;
 114
 115 no_match:
 116         return 0;
 117 }
 118
 119 /*
 120  * Find the channel in the hashtable and return channel pointer. RCU read side
 121  * lock MUST be acquired before calling this.
 122  */
 123 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 124                 char *name)
 125 {
 126         struct lttng_ht_node_str *node;
 127         struct lttng_ht_iter iter;
 128
 129         lttng_ht_lookup(ht, (void *)name, &iter);
 130         node = lttng_ht_iter_get_node_str(&iter);
 131         if (node == NULL) {
 132                 goto error;
 133         }
 134
 135         DBG2("Trace UST channel %s found by name", name);
 136
 137         return caa_container_of(node, struct ltt_ust_channel, node);
 138
 139 error:
 140         DBG2("Trace UST channel %s not found by name", name);
 141         return NULL;
 142 }
 143
 144 /*
 145  * Find the event in the hashtable and return event pointer. RCU read side lock
 146  * MUST be acquired before calling this.
 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)
 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         /*
 200          * Default buffer type. This can be changed through an enable channel
 201          * requesting a different type. Note that this can only be changed once
 202          * during the session lifetime which is at the first enable channel and
 203          * only before start. The flag buffer_type_changed indicates the status.
 204          */
 205         lus->buffer_type = LTTNG_BUFFER_PER_PID;
 206         /* Once set to 1, the buffer_type is immutable for the session. */
 207         lus->buffer_type_changed = 0;
 208         /* Init it in case it get used after allocation. */
 209         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 210
 211         /* Alloc UST global domain channels' HT */
 212         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 213
 214         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 215         if (lus->consumer == NULL) {
 216                 goto error_consumer;
 217         }
 218
 219         /*
 220          * The tmp_consumer stays NULL until a set_consumer_uri command is
 221          * executed. At this point, the consumer should be nullify until an
 222          * enable_consumer command. This assignment is symbolic since we've zmalloc
 223          * the struct.
 224          */
 225         lus->tmp_consumer = NULL;
 226
 227         /* Use the default consumer output which is the tracing session path. */
 228         if (*path != '\0') {
 229                 int ret;
 230
 231                 ret = snprintf(lus->consumer->dst.trace_path, PATH_MAX,
 232                                 "%s" DEFAULT_UST_TRACE_DIR, path);
 233                 if (ret < 0) {
 234                         PERROR("snprintf UST consumer trace 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         free(lus);
 248 error:
 249         return NULL;
 250 }
 251
 252 /*
 253  * Allocate and initialize a ust channel data structure.
 254  *
 255  * Return pointer to structure or NULL.
 256  */
 257 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 258                 char *path)
 259 {
 260         struct ltt_ust_channel *luc;
 261
 262         assert(chan);
 263         assert(path);
 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         /* On-disk circular buffer parameters */
 297         luc->tracefile_size = chan->attr.tracefile_size;
 298         luc->tracefile_count = chan->attr.tracefile_count;
 299
 300         DBG2("Trace UST channel %s created", luc->name);
 301
 302 error:
 303         return luc;
 304 }
 305
 306 /*
 307  * Allocate and initialize a ust event. Set name and event type.
 308  *
 309  * Return pointer to structure or NULL.
 310  */
 311 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 312                 struct lttng_filter_bytecode *filter)
 313 {
 314         struct ltt_ust_event *lue;
 315
 316         assert(ev);
 317
 318         lue = zmalloc(sizeof(struct ltt_ust_event));
 319         if (lue == NULL) {
 320                 PERROR("ust event zmalloc");
 321                 goto error;
 322         }
 323
 324         switch (ev->type) {
 325         case LTTNG_EVENT_PROBE:
 326                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 327                 break;
 328         case LTTNG_EVENT_FUNCTION:
 329                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 330                 break;
 331         case LTTNG_EVENT_FUNCTION_ENTRY:
 332                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 333                 break;
 334         case LTTNG_EVENT_TRACEPOINT:
 335                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 336                 break;
 337         default:
 338                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 339                 goto error_free_event;
 340         }
 341
 342         /* Copy event name */
 343         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 344         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 345
 346         switch (ev->loglevel_type) {
 347         case LTTNG_EVENT_LOGLEVEL_ALL:
 348                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 349                 lue->attr.loglevel = -1;        /* Force to -1 */
 350                 break;
 351         case LTTNG_EVENT_LOGLEVEL_RANGE:
 352                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 353                 lue->attr.loglevel = ev->loglevel;
 354                 break;
 355         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 356                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 357                 lue->attr.loglevel = ev->loglevel;
 358                 break;
 359         default:
 360                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 361                 goto error_free_event;
 362         }
 363
 364         /* Same layout. */
 365         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 366
 367         /* Init node */
 368         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 369
 370         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 371                 lue->attr.name, lue->attr.loglevel_type,
 372                 lue->attr.loglevel);
 373
 374         return lue;
 375
 376 error_free_event:
 377         free(lue);
 378 error:
 379         return NULL;
 380 }
 381
 382 /*
 383  * Allocate and initialize a ust metadata.
 384  *
 385  * Return pointer to structure or NULL.
 386  */
 387 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 388 {
 389         int ret;
 390         struct ltt_ust_metadata *lum;
 391
 392         assert(path);
 393
 394         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 395         if (lum == NULL) {
 396                 PERROR("ust metadata zmalloc");
 397                 goto error;
 398         }
 399
 400         /* Set default attributes */
 401         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 402         lum->attr.subbuf_size = default_get_metadata_subbuf_size();
 403         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 404         lum->attr.switch_timer_interval = DEFAULT_UST_CHANNEL_SWITCH_TIMER;
 405         lum->attr.read_timer_interval = DEFAULT_UST_CHANNEL_READ_TIMER;
 406         lum->attr.output = LTTNG_UST_MMAP;
 407
 408         lum->handle = -1;
 409         /* Set metadata trace path */
 410         ret = snprintf(lum->pathname, PATH_MAX, "%s/" DEFAULT_METADATA_NAME, path);
 411         if (ret < 0) {
 412                 PERROR("asprintf ust metadata");
 413                 goto error_free_metadata;
 414         }
 415
 416         return lum;
 417
 418 error_free_metadata:
 419         free(lum);
 420 error:
 421         return NULL;
 422 }
 423
 424 /*
 425  * Allocate and initialize an UST context.
 426  *
 427  * Return pointer to structure or NULL.
 428  */
 429 struct ltt_ust_context *trace_ust_create_context(
 430                 struct lttng_event_context *ctx)
 431 {
 432         struct ltt_ust_context *uctx;
 433         enum lttng_ust_context_type utype;
 434
 435         assert(ctx);
 436
 437         switch (ctx->ctx) {
 438         case LTTNG_EVENT_CONTEXT_VTID:
 439                 utype = LTTNG_UST_CONTEXT_VTID;
 440                 break;
 441         case LTTNG_EVENT_CONTEXT_VPID:
 442                 utype = LTTNG_UST_CONTEXT_VPID;
 443                 break;
 444         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 445                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 446                 break;
 447         case LTTNG_EVENT_CONTEXT_PROCNAME:
 448                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 449                 break;
 450         default:
 451                 ERR("Invalid UST context");
 452                 return NULL;
 453         }
 454
 455         uctx = zmalloc(sizeof(struct ltt_ust_context));
 456         if (uctx == NULL) {
 457                 PERROR("zmalloc ltt_ust_context");
 458                 goto error;
 459         }
 460
 461         uctx->ctx.ctx = utype;
 462         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 463
 464         return uctx;
 465
 466 error:
 467         return NULL;
 468 }
 469
 470 /*
 471  * RCU safe free context structure.
 472  */
 473 static void destroy_context_rcu(struct rcu_head *head)
 474 {
 475         struct lttng_ht_node_ulong *node =
 476                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 477         struct ltt_ust_context *ctx =
 478                 caa_container_of(node, struct ltt_ust_context, node);
 479
 480         free(ctx);
 481 }
 482
 483 /*
 484  * Cleanup UST context hash table.
 485  */
 486 static void destroy_contexts(struct lttng_ht *ht)
 487 {
 488         int ret;
 489         struct lttng_ht_node_ulong *node;
 490         struct lttng_ht_iter iter;
 491
 492         assert(ht);
 493
 494         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 495                 ret = lttng_ht_del(ht, &iter);
 496                 if (!ret) {
 497                         call_rcu(&node->head, destroy_context_rcu);
 498                 }
 499         }
 500
 501         lttng_ht_destroy(ht);
 502 }
 503
 504 /*
 505  * Cleanup ust event structure.
 506  */
 507 void trace_ust_destroy_event(struct ltt_ust_event *event)
 508 {
 509         assert(event);
 510
 511         DBG2("Trace destroy UST event %s", event->attr.name);
 512         free(event->filter);
 513         free(event);
 514 }
 515
 516 /*
 517  * URCU intermediate call to complete destroy event.
 518  */
 519 static void destroy_event_rcu(struct rcu_head *head)
 520 {
 521         struct lttng_ht_node_str *node =
 522                 caa_container_of(head, struct lttng_ht_node_str, head);
 523         struct ltt_ust_event *event =
 524                 caa_container_of(node, struct ltt_ust_event, node);
 525
 526         trace_ust_destroy_event(event);
 527 }
 528
 529 /*
 530  * Cleanup UST events hashtable.
 531  */
 532 static void destroy_events(struct lttng_ht *events)
 533 {
 534         int ret;
 535         struct lttng_ht_node_str *node;
 536         struct lttng_ht_iter iter;
 537
 538         assert(events);
 539
 540         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 541                 ret = lttng_ht_del(events, &iter);
 542                 assert(!ret);
 543                 call_rcu(&node->head, destroy_event_rcu);
 544         }
 545
 546         lttng_ht_destroy(events);
 547 }
 548
 549 /*
 550  * Cleanup ust channel structure.
 551  */
 552 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 553 {
 554         assert(channel);
 555
 556         DBG2("Trace destroy UST channel %s", channel->name);
 557
 558         rcu_read_lock();
 559
 560         /* Destroying all events of the channel */
 561         destroy_events(channel->events);
 562         /* Destroying all context of the channel */
 563         destroy_contexts(channel->ctx);
 564
 565         free(channel);
 566
 567         rcu_read_unlock();
 568 }
 569
 570 /*
 571  * URCU intermediate call to complete destroy channel.
 572  */
 573 static void destroy_channel_rcu(struct rcu_head *head)
 574 {
 575         struct lttng_ht_node_str *node =
 576                 caa_container_of(head, struct lttng_ht_node_str, head);
 577         struct ltt_ust_channel *channel =
 578                 caa_container_of(node, struct ltt_ust_channel, node);
 579
 580         trace_ust_destroy_channel(channel);
 581 }
 582
 583 /*
 584  * Cleanup ust metadata structure.
 585  */
 586 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 587 {
 588         assert(metadata);
 589
 590         if (!metadata->handle) {
 591                 return;
 592         }
 593         DBG2("Trace UST destroy metadata %d", metadata->handle);
 594         free(metadata);
 595 }
 596
 597 /*
 598  * Iterate over a hash table containing channels and cleanup safely.
 599  */
 600 static void destroy_channels(struct lttng_ht *channels)
 601 {
 602         int ret;
 603         struct lttng_ht_node_str *node;
 604         struct lttng_ht_iter iter;
 605
 606         assert(channels);
 607
 608         rcu_read_lock();
 609
 610         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 611                 ret = lttng_ht_del(channels, &iter);
 612                 assert(!ret);
 613                 call_rcu(&node->head, destroy_channel_rcu);
 614         }
 615
 616         lttng_ht_destroy(channels);
 617
 618         rcu_read_unlock();
 619 }
 620
 621 /*
 622  * Cleanup UST global domain.
 623  */
 624 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 625 {
 626         assert(dom);
 627
 628         destroy_channels(dom->channels);
 629 }
 630
 631 /*
 632  * Cleanup ust session structure
 633  */
 634 void trace_ust_destroy_session(struct ltt_ust_session *session)
 635 {
 636         struct buffer_reg_uid *reg, *sreg;
 637
 638         assert(session);
 639
 640         rcu_read_lock();
 641
 642         DBG2("Trace UST destroy session %u", session->id);
 643
 644         /* Cleaning up UST domain */
 645         destroy_domain_global(&session->domain_global);
 646
 647         /* Cleanup UID buffer registry object(s). */
 648         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 649                         lnode) {
 650                 cds_list_del(&reg->lnode);
 651                 buffer_reg_uid_remove(reg);
 652                 buffer_reg_uid_destroy(reg, session->consumer);
 653         }
 654
 655         consumer_destroy_output(session->consumer);
 656         consumer_destroy_output(session->tmp_consumer);
 657
 658         free(session);
 659
 660         rcu_read_unlock();
 661 }