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 #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
  32 /*
  33  * Match function for the events hash table lookup.
  34  *
  35  * Matches by name only. Used by the disable command.
  36  */
  37 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  38                 const void *_key)
  39 {
  40         struct ltt_ust_event *event;
  41         const char *name;
  42
  43         assert(node);
  44         assert(_key);
  45
  46         event = caa_container_of(node, struct ltt_ust_event, node.node);
  47         name = _key;
  48
  49         /* Event name */
  50         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  51                 goto no_match;
  52         }
  53
  54         /* Match */
  55         return 1;
  56
  57 no_match:
  58         return 0;
  59 }
  60
  61 /*
  62  * Match function for the hash table lookup.
  63  *
  64  * It matches an ust event based on three attributes which are the event name,
  65  * the filter bytecode and the loglevel.
  66  */
  67 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  68 {
  69         struct ltt_ust_event *event;
  70         const struct ltt_ust_ht_key *key;
  71
  72         assert(node);
  73         assert(_key);
  74
  75         event = caa_container_of(node, struct ltt_ust_event, node.node);
  76         key = _key;
  77
  78         /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
  79
  80         /* Event name */
  81         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  82                 goto no_match;
  83         }
  84
  85         /* Event loglevel. */
  86         if (event->attr.loglevel != key->loglevel) {
  87                 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
  88                                 && key->loglevel == 0 && event->attr.loglevel == -1) {
  89                         /*
  90                          * Match is accepted. This is because on event creation, the
  91                          * loglevel is set to -1 if the event loglevel type is ALL so 0 and
  92                          * -1 are accepted for this loglevel type since 0 is the one set by
  93                          * the API when receiving an enable event.
  94                          */
  95                 } else {
  96                         goto no_match;
  97                 }
  98         }
  99
 100         /* Only one of the filters is NULL, fail. */
 101         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 102                 goto no_match;
 103         }
 104
 105         if (key->filter && event->filter) {
 106                 /* Both filters exists, check length followed by the bytecode. */
 107                 if (event->filter->len != key->filter->len ||
 108                                 memcmp(event->filter->data, key->filter->data,
 109                                         event->filter->len) != 0) {
 110                         goto no_match;
 111                 }
 112         }
 113
 114         /* If only one of the exclusions is NULL, fail. */
 115         if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
 116                 goto no_match;
 117         }
 118
 119         if (key->exclusion && event->exclusion) {
 120                 /* Both exclusions exist; check count followed by names. */
 121                 if (event->exclusion->count != key->exclusion->count ||
 122                                 memcmp(event->exclusion->names, key->exclusion->names,
 123                                         event->exclusion->count * LTTNG_SYMBOL_NAME_LEN) != 0) {
 124                         goto no_match;
 125                 }
 126         }
 127         /* Match. */
 128         return 1;
 129
 130 no_match:
 131         return 0;
 132 }
 133
 134 /*
 135  * Find the channel in the hashtable and return channel pointer. RCU read side
 136  * lock MUST be acquired before calling this.
 137  */
 138 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 139                 char *name)
 140 {
 141         struct lttng_ht_node_str *node;
 142         struct lttng_ht_iter iter;
 143
 144         /*
 145          * If we receive an empty string for channel name, it means the
 146          * default channel name is requested.
 147          */
 148         if (name[0] == '\0')
 149                 name = DEFAULT_CHANNEL_NAME;
 150
 151         lttng_ht_lookup(ht, (void *)name, &iter);
 152         node = lttng_ht_iter_get_node_str(&iter);
 153         if (node == NULL) {
 154                 goto error;
 155         }
 156
 157         DBG2("Trace UST channel %s found by name", name);
 158
 159         return caa_container_of(node, struct ltt_ust_channel, node);
 160
 161 error:
 162         DBG2("Trace UST channel %s not found by name", name);
 163         return NULL;
 164 }
 165
 166 /*
 167  * Find the event in the hashtable and return event pointer. RCU read side lock
 168  * MUST be acquired before calling this.
 169  */
 170 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 171                 char *name, struct lttng_filter_bytecode *filter, int loglevel,
 172                 struct lttng_event_exclusion *exclusion)
 173 {
 174         struct lttng_ht_node_str *node;
 175         struct lttng_ht_iter iter;
 176         struct ltt_ust_ht_key key;
 177
 178         assert(name);
 179         assert(ht);
 180
 181         key.name = name;
 182         key.filter = filter;
 183         key.loglevel = loglevel;
 184         key.exclusion = exclusion;
 185
 186         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 187                         trace_ust_ht_match_event, &key, &iter.iter);
 188         node = lttng_ht_iter_get_node_str(&iter);
 189         if (node == NULL) {
 190                 goto error;
 191         }
 192
 193         DBG2("Trace UST event %s found", key.name);
 194
 195         return caa_container_of(node, struct ltt_ust_event, node);
 196
 197 error:
 198         DBG2("Trace UST event %s NOT found", key.name);
 199         return NULL;
 200 }
 201
 202 /*
 203  * Allocate and initialize a ust session data structure.
 204  *
 205  * Return pointer to structure or NULL.
 206  */
 207 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 208 {
 209         int ret;
 210         struct ltt_ust_session *lus;
 211
 212         /* Allocate a new ltt ust session */
 213         lus = zmalloc(sizeof(struct ltt_ust_session));
 214         if (lus == NULL) {
 215                 PERROR("create ust session zmalloc");
 216                 goto error;
 217         }
 218
 219         /* Init data structure */
 220         lus->id = session_id;
 221         lus->start_trace = 0;
 222
 223         /* Set default metadata channel attribute. */
 224         lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 225         lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
 226         lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 227         lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 228         lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 229         lus->metadata_attr.output = LTTNG_UST_MMAP;
 230
 231         /*
 232          * Default buffer type. This can be changed through an enable channel
 233          * requesting a different type. Note that this can only be changed once
 234          * during the session lifetime which is at the first enable channel and
 235          * only before start. The flag buffer_type_changed indicates the status.
 236          */
 237         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 238         /* Once set to 1, the buffer_type is immutable for the session. */
 239         lus->buffer_type_changed = 0;
 240         /* Init it in case it get used after allocation. */
 241         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 242
 243         /* Alloc UST global domain channels' HT */
 244         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 245         ret = jul_init_domain(&lus->domain_jul);
 246         if (ret < 0) {
 247                 goto error_consumer;
 248         }
 249
 250         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 251         if (lus->consumer == NULL) {
 252                 goto error_consumer;
 253         }
 254
 255         /*
 256          * The tmp_consumer stays NULL until a set_consumer_uri command is
 257          * executed. At this point, the consumer should be nullify until an
 258          * enable_consumer command. This assignment is symbolic since we've zmalloc
 259          * the struct.
 260          */
 261         lus->tmp_consumer = NULL;
 262
 263         DBG2("UST trace session create successful");
 264
 265         return lus;
 266
 267 error_consumer:
 268         ht_cleanup_push(lus->domain_global.channels);
 269         jul_destroy_domain(&lus->domain_jul);
 270         free(lus);
 271 error:
 272         return NULL;
 273 }
 274
 275 /*
 276  * Allocate and initialize a ust channel data structure.
 277  *
 278  * Return pointer to structure or NULL.
 279  */
 280 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan)
 281 {
 282         struct ltt_ust_channel *luc;
 283
 284         assert(chan);
 285
 286         luc = zmalloc(sizeof(struct ltt_ust_channel));
 287         if (luc == NULL) {
 288                 PERROR("ltt_ust_channel zmalloc");
 289                 goto error;
 290         }
 291
 292         /* Copy UST channel attributes */
 293         luc->attr.overwrite = chan->attr.overwrite;
 294         luc->attr.subbuf_size = chan->attr.subbuf_size;
 295         luc->attr.num_subbuf = chan->attr.num_subbuf;
 296         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 297         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 298         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 299
 300         /* Translate to UST output enum */
 301         switch (luc->attr.output) {
 302         default:
 303                 luc->attr.output = LTTNG_UST_MMAP;
 304                 break;
 305         }
 306
 307         /*
 308          * If we receive an empty string for channel name, it means the
 309          * default channel name is requested.
 310          */
 311         if (chan->name[0] == '\0') {
 312                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 313         } else {
 314                 /* Copy channel name */
 315                 strncpy(luc->name, chan->name, sizeof(luc->name));
 316         }
 317         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 318
 319         /* Init node */
 320         lttng_ht_node_init_str(&luc->node, luc->name);
 321         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 322
 323         /* Alloc hash tables */
 324         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 325         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 326
 327         /* On-disk circular buffer parameters */
 328         luc->tracefile_size = chan->attr.tracefile_size;
 329         luc->tracefile_count = chan->attr.tracefile_count;
 330
 331         DBG2("Trace UST channel %s created", luc->name);
 332
 333 error:
 334         return luc;
 335 }
 336
 337 /*
 338  * Allocate and initialize a ust event. Set name and event type.
 339  *
 340  * Return pointer to structure or NULL.
 341  */
 342 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 343                 struct lttng_filter_bytecode *filter,
 344                 struct lttng_event_exclusion *exclusion)
 345 {
 346         struct ltt_ust_event *lue;
 347
 348         assert(ev);
 349
 350         lue = zmalloc(sizeof(struct ltt_ust_event));
 351         if (lue == NULL) {
 352                 PERROR("ust event zmalloc");
 353                 goto error;
 354         }
 355
 356         switch (ev->type) {
 357         case LTTNG_EVENT_PROBE:
 358                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 359                 break;
 360         case LTTNG_EVENT_FUNCTION:
 361                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 362                 break;
 363         case LTTNG_EVENT_FUNCTION_ENTRY:
 364                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 365                 break;
 366         case LTTNG_EVENT_TRACEPOINT:
 367                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 368                 break;
 369         default:
 370                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 371                 goto error_free_event;
 372         }
 373
 374         /* Copy event name */
 375         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 376         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 377
 378         switch (ev->loglevel_type) {
 379         case LTTNG_EVENT_LOGLEVEL_ALL:
 380                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 381                 lue->attr.loglevel = -1;        /* Force to -1 */
 382                 break;
 383         case LTTNG_EVENT_LOGLEVEL_RANGE:
 384                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 385                 lue->attr.loglevel = ev->loglevel;
 386                 break;
 387         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 388                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 389                 lue->attr.loglevel = ev->loglevel;
 390                 break;
 391         default:
 392                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 393                 goto error_free_event;
 394         }
 395         /*
 396          * Fix for enabler race. Enable is now done explicitly by
 397          * sessiond after setting filter.
 398          */
 399         lue->attr.disabled = 1;
 400
 401         /* Same layout. */
 402         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 403         lue->exclusion = (struct lttng_event_exclusion *) exclusion;
 404
 405         /* Init node */
 406         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 407
 408         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 409                 lue->attr.name, lue->attr.loglevel_type,
 410                 lue->attr.loglevel);
 411
 412         return lue;
 413
 414 error_free_event:
 415         free(lue);
 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         case LTTNG_EVENT_CONTEXT_IP:
 447                 utype = LTTNG_UST_CONTEXT_IP;
 448                 break;
 449         default:
 450                 ERR("Invalid UST context");
 451                 return NULL;
 452         }
 453
 454         uctx = zmalloc(sizeof(struct ltt_ust_context));
 455         if (uctx == NULL) {
 456                 PERROR("zmalloc ltt_ust_context");
 457                 goto error;
 458         }
 459
 460         uctx->ctx.ctx = utype;
 461         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 462         CDS_INIT_LIST_HEAD(&uctx->list);
 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         struct ltt_ust_context *ctx;
 492
 493         assert(ht);
 494
 495         rcu_read_lock();
 496         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 497                 /* Remove from ordered list. */
 498                 ctx = caa_container_of(node, struct ltt_ust_context, node);
 499                 cds_list_del(&ctx->list);
 500                 /* Remove from channel's hash table. */
 501                 ret = lttng_ht_del(ht, &iter);
 502                 if (!ret) {
 503                         call_rcu(&node->head, destroy_context_rcu);
 504                 }
 505         }
 506         rcu_read_unlock();
 507
 508         ht_cleanup_push(ht);
 509 }
 510
 511 /*
 512  * Cleanup ust event structure.
 513  */
 514 void trace_ust_destroy_event(struct ltt_ust_event *event)
 515 {
 516         assert(event);
 517
 518         DBG2("Trace destroy UST event %s", event->attr.name);
 519         free(event->filter);
 520         free(event->exclusion);
 521         free(event);
 522 }
 523
 524 /*
 525  * URCU intermediate call to complete destroy event.
 526  */
 527 static void destroy_event_rcu(struct rcu_head *head)
 528 {
 529         struct lttng_ht_node_str *node =
 530                 caa_container_of(head, struct lttng_ht_node_str, head);
 531         struct ltt_ust_event *event =
 532                 caa_container_of(node, struct ltt_ust_event, node);
 533
 534         trace_ust_destroy_event(event);
 535 }
 536
 537 /*
 538  * Cleanup UST events hashtable.
 539  */
 540 static void destroy_events(struct lttng_ht *events)
 541 {
 542         int ret;
 543         struct lttng_ht_node_str *node;
 544         struct lttng_ht_iter iter;
 545
 546         assert(events);
 547
 548         rcu_read_lock();
 549         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 550                 ret = lttng_ht_del(events, &iter);
 551                 assert(!ret);
 552                 call_rcu(&node->head, destroy_event_rcu);
 553         }
 554         rcu_read_unlock();
 555
 556         ht_cleanup_push(events);
 557 }
 558
 559 /*
 560  * Cleanup ust channel structure.
 561  *
 562  * Should _NOT_ be called with RCU read lock held.
 563  */
 564 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 565 {
 566         assert(channel);
 567
 568         DBG2("Trace destroy UST channel %s", channel->name);
 569
 570         /* Destroying all events of the channel */
 571         destroy_events(channel->events);
 572         /* Destroying all context of the channel */
 573         destroy_contexts(channel->ctx);
 574
 575         free(channel);
 576 }
 577
 578 /*
 579  * URCU intermediate call to complete destroy channel.
 580  */
 581 static void destroy_channel_rcu(struct rcu_head *head)
 582 {
 583         struct lttng_ht_node_str *node =
 584                 caa_container_of(head, struct lttng_ht_node_str, head);
 585         struct ltt_ust_channel *channel =
 586                 caa_container_of(node, struct ltt_ust_channel, node);
 587
 588         _trace_ust_destroy_channel(channel);
 589 }
 590
 591 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 592 {
 593         call_rcu(&channel->node.head, destroy_channel_rcu);
 594 }
 595
 596 /*
 597  * Remove an UST channel from a channel HT.
 598  */
 599 void trace_ust_delete_channel(struct lttng_ht *ht,
 600                 struct ltt_ust_channel *channel)
 601 {
 602         int ret;
 603         struct lttng_ht_iter iter;
 604
 605         assert(ht);
 606         assert(channel);
 607
 608         iter.iter.node = &channel->node.node;
 609         ret = lttng_ht_del(ht, &iter);
 610         assert(!ret);
 611 }
 612
 613 /*
 614  * Iterate over a hash table containing channels and cleanup safely.
 615  */
 616 static void destroy_channels(struct lttng_ht *channels)
 617 {
 618         int ret;
 619         struct lttng_ht_node_str *node;
 620         struct lttng_ht_iter iter;
 621
 622         assert(channels);
 623
 624         rcu_read_lock();
 625
 626         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 627                 ret = lttng_ht_del(channels, &iter);
 628                 assert(!ret);
 629                 call_rcu(&node->head, destroy_channel_rcu);
 630         }
 631         rcu_read_unlock();
 632
 633         ht_cleanup_push(channels);
 634 }
 635
 636 /*
 637  * Cleanup UST global domain.
 638  */
 639 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 640 {
 641         assert(dom);
 642
 643         destroy_channels(dom->channels);
 644 }
 645
 646 /*
 647  * Cleanup ust session structure
 648  *
 649  * Should *NOT* be called with RCU read-side lock held.
 650  */
 651 void trace_ust_destroy_session(struct ltt_ust_session *session)
 652 {
 653         struct buffer_reg_uid *reg, *sreg;
 654
 655         assert(session);
 656
 657         DBG2("Trace UST destroy session %" PRIu64, session->id);
 658
 659         /* Cleaning up UST domain */
 660         destroy_domain_global(&session->domain_global);
 661         jul_destroy_domain(&session->domain_jul);
 662
 663         /* Cleanup UID buffer registry object(s). */
 664         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 665                         lnode) {
 666                 cds_list_del(&reg->lnode);
 667                 buffer_reg_uid_remove(reg);
 668                 buffer_reg_uid_destroy(reg, session->consumer);
 669         }
 670
 671         consumer_destroy_output(session->consumer);
 672         consumer_destroy_output(session->tmp_consumer);
 673
 674         free(session);
 675 }