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         DBG2("Trace UST channel %s created", luc->name);
 297
 298 error:
 299         return luc;
 300 }
 301
 302 /*
 303  * Allocate and initialize a ust event. Set name and event type.
 304  *
 305  * Return pointer to structure or NULL.
 306  */
 307 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 308                 struct lttng_filter_bytecode *filter)
 309 {
 310         struct ltt_ust_event *lue;
 311
 312         assert(ev);
 313
 314         lue = zmalloc(sizeof(struct ltt_ust_event));
 315         if (lue == NULL) {
 316                 PERROR("ust event zmalloc");
 317                 goto error;
 318         }
 319
 320         switch (ev->type) {
 321         case LTTNG_EVENT_PROBE:
 322                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 323                 break;
 324         case LTTNG_EVENT_FUNCTION:
 325                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 326                 break;
 327         case LTTNG_EVENT_FUNCTION_ENTRY:
 328                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 329                 break;
 330         case LTTNG_EVENT_TRACEPOINT:
 331                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 332                 break;
 333         default:
 334                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 335                 goto error_free_event;
 336         }
 337
 338         /* Copy event name */
 339         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 340         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 341
 342         switch (ev->loglevel_type) {
 343         case LTTNG_EVENT_LOGLEVEL_ALL:
 344                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 345                 lue->attr.loglevel = -1;        /* Force to -1 */
 346                 break;
 347         case LTTNG_EVENT_LOGLEVEL_RANGE:
 348                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 349                 lue->attr.loglevel = ev->loglevel;
 350                 break;
 351         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 352                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 353                 lue->attr.loglevel = ev->loglevel;
 354                 break;
 355         default:
 356                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 357                 goto error_free_event;
 358         }
 359
 360         /* Same layout. */
 361         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 362
 363         /* Init node */
 364         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 365
 366         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 367                 lue->attr.name, lue->attr.loglevel_type,
 368                 lue->attr.loglevel);
 369
 370         return lue;
 371
 372 error_free_event:
 373         free(lue);
 374 error:
 375         return NULL;
 376 }
 377
 378 /*
 379  * Allocate and initialize a ust metadata.
 380  *
 381  * Return pointer to structure or NULL.
 382  */
 383 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 384 {
 385         int ret;
 386         struct ltt_ust_metadata *lum;
 387
 388         assert(path);
 389
 390         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 391         if (lum == NULL) {
 392                 PERROR("ust metadata zmalloc");
 393                 goto error;
 394         }
 395
 396         /* Set default attributes */
 397         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 398         lum->attr.subbuf_size = default_get_metadata_subbuf_size();
 399         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 400         lum->attr.switch_timer_interval = DEFAULT_UST_CHANNEL_SWITCH_TIMER;
 401         lum->attr.read_timer_interval = DEFAULT_UST_CHANNEL_READ_TIMER;
 402         lum->attr.output = LTTNG_UST_MMAP;
 403
 404         lum->handle = -1;
 405         /* Set metadata trace path */
 406         ret = snprintf(lum->pathname, PATH_MAX, "%s/" DEFAULT_METADATA_NAME, path);
 407         if (ret < 0) {
 408                 PERROR("asprintf ust metadata");
 409                 goto error_free_metadata;
 410         }
 411
 412         return lum;
 413
 414 error_free_metadata:
 415         free(lum);
 416 error:
 417         return NULL;
 418 }
 419
 420 /*
 421  * Allocate and initialize an UST context.
 422  *
 423  * Return pointer to structure or NULL.
 424  */
 425 struct ltt_ust_context *trace_ust_create_context(
 426                 struct lttng_event_context *ctx)
 427 {
 428         struct ltt_ust_context *uctx;
 429         enum lttng_ust_context_type utype;
 430
 431         assert(ctx);
 432
 433         switch (ctx->ctx) {
 434         case LTTNG_EVENT_CONTEXT_VTID:
 435                 utype = LTTNG_UST_CONTEXT_VTID;
 436                 break;
 437         case LTTNG_EVENT_CONTEXT_VPID:
 438                 utype = LTTNG_UST_CONTEXT_VPID;
 439                 break;
 440         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 441                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 442                 break;
 443         case LTTNG_EVENT_CONTEXT_PROCNAME:
 444                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 445                 break;
 446         default:
 447                 ERR("Invalid UST context");
 448                 return NULL;
 449         }
 450
 451         uctx = zmalloc(sizeof(struct ltt_ust_context));
 452         if (uctx == NULL) {
 453                 PERROR("zmalloc ltt_ust_context");
 454                 goto error;
 455         }
 456
 457         uctx->ctx.ctx = utype;
 458         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 459
 460         return uctx;
 461
 462 error:
 463         return NULL;
 464 }
 465
 466 /*
 467  * RCU safe free context structure.
 468  */
 469 static void destroy_context_rcu(struct rcu_head *head)
 470 {
 471         struct lttng_ht_node_ulong *node =
 472                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 473         struct ltt_ust_context *ctx =
 474                 caa_container_of(node, struct ltt_ust_context, node);
 475
 476         free(ctx);
 477 }
 478
 479 /*
 480  * Cleanup UST context hash table.
 481  */
 482 static void destroy_contexts(struct lttng_ht *ht)
 483 {
 484         int ret;
 485         struct lttng_ht_node_ulong *node;
 486         struct lttng_ht_iter iter;
 487
 488         assert(ht);
 489
 490         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 491                 ret = lttng_ht_del(ht, &iter);
 492                 if (!ret) {
 493                         call_rcu(&node->head, destroy_context_rcu);
 494                 }
 495         }
 496
 497         lttng_ht_destroy(ht);
 498 }
 499
 500 /*
 501  * Cleanup ust event structure.
 502  */
 503 void trace_ust_destroy_event(struct ltt_ust_event *event)
 504 {
 505         assert(event);
 506
 507         DBG2("Trace destroy UST event %s", event->attr.name);
 508         free(event->filter);
 509         free(event);
 510 }
 511
 512 /*
 513  * URCU intermediate call to complete destroy event.
 514  */
 515 static void destroy_event_rcu(struct rcu_head *head)
 516 {
 517         struct lttng_ht_node_str *node =
 518                 caa_container_of(head, struct lttng_ht_node_str, head);
 519         struct ltt_ust_event *event =
 520                 caa_container_of(node, struct ltt_ust_event, node);
 521
 522         trace_ust_destroy_event(event);
 523 }
 524
 525 /*
 526  * Cleanup UST events hashtable.
 527  */
 528 static void destroy_events(struct lttng_ht *events)
 529 {
 530         int ret;
 531         struct lttng_ht_node_str *node;
 532         struct lttng_ht_iter iter;
 533
 534         assert(events);
 535
 536         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 537                 ret = lttng_ht_del(events, &iter);
 538                 assert(!ret);
 539                 call_rcu(&node->head, destroy_event_rcu);
 540         }
 541
 542         lttng_ht_destroy(events);
 543 }
 544
 545 /*
 546  * Cleanup ust channel structure.
 547  */
 548 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 549 {
 550         assert(channel);
 551
 552         DBG2("Trace destroy UST channel %s", channel->name);
 553
 554         rcu_read_lock();
 555
 556         /* Destroying all events of the channel */
 557         destroy_events(channel->events);
 558         /* Destroying all context of the channel */
 559         destroy_contexts(channel->ctx);
 560
 561         free(channel);
 562
 563         rcu_read_unlock();
 564 }
 565
 566 /*
 567  * URCU intermediate call to complete destroy channel.
 568  */
 569 static void destroy_channel_rcu(struct rcu_head *head)
 570 {
 571         struct lttng_ht_node_str *node =
 572                 caa_container_of(head, struct lttng_ht_node_str, head);
 573         struct ltt_ust_channel *channel =
 574                 caa_container_of(node, struct ltt_ust_channel, node);
 575
 576         trace_ust_destroy_channel(channel);
 577 }
 578
 579 /*
 580  * Cleanup ust metadata structure.
 581  */
 582 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 583 {
 584         assert(metadata);
 585
 586         if (!metadata->handle) {
 587                 return;
 588         }
 589         DBG2("Trace UST destroy metadata %d", metadata->handle);
 590         free(metadata);
 591 }
 592
 593 /*
 594  * Iterate over a hash table containing channels and cleanup safely.
 595  */
 596 static void destroy_channels(struct lttng_ht *channels)
 597 {
 598         int ret;
 599         struct lttng_ht_node_str *node;
 600         struct lttng_ht_iter iter;
 601
 602         assert(channels);
 603
 604         rcu_read_lock();
 605
 606         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 607                 ret = lttng_ht_del(channels, &iter);
 608                 assert(!ret);
 609                 call_rcu(&node->head, destroy_channel_rcu);
 610         }
 611
 612         lttng_ht_destroy(channels);
 613
 614         rcu_read_unlock();
 615 }
 616
 617 /*
 618  * Cleanup UST global domain.
 619  */
 620 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 621 {
 622         assert(dom);
 623
 624         destroy_channels(dom->channels);
 625 }
 626
 627 /*
 628  * Cleanup ust session structure
 629  */
 630 void trace_ust_destroy_session(struct ltt_ust_session *session)
 631 {
 632         struct buffer_reg_uid *reg, *sreg;
 633
 634         assert(session);
 635
 636         rcu_read_lock();
 637
 638         DBG2("Trace UST destroy session %u", session->id);
 639
 640         /* Cleaning up UST domain */
 641         destroy_domain_global(&session->domain_global);
 642
 643         /* Cleanup UID buffer registry object(s). */
 644         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 645                         lnode) {
 646                 cds_list_del(&reg->lnode);
 647                 buffer_reg_uid_remove(reg);
 648                 buffer_reg_uid_destroy(reg, session->consumer);
 649         }
 650
 651         consumer_destroy_output(session->consumer);
 652         consumer_destroy_output(session->tmp_consumer);
 653
 654         free(session);
 655
 656         rcu_read_unlock();
 657 }