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         /*
 224          * Default buffer type. This can be changed through an enable channel
 225          * requesting a different type. Note that this can only be changed once
 226          * during the session lifetime which is at the first enable channel and
 227          * only before start. The flag buffer_type_changed indicates the status.
 228          */
 229         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 230         /* Once set to 1, the buffer_type is immutable for the session. */
 231         lus->buffer_type_changed = 0;
 232         /* Init it in case it get used after allocation. */
 233         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 234
 235         /* Alloc UST global domain channels' HT */
 236         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 237         ret = jul_init_domain(&lus->domain_jul);
 238         if (ret < 0) {
 239                 goto error_consumer;
 240         }
 241
 242         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 243         if (lus->consumer == NULL) {
 244                 goto error_consumer;
 245         }
 246
 247         /*
 248          * The tmp_consumer stays NULL until a set_consumer_uri command is
 249          * executed. At this point, the consumer should be nullify until an
 250          * enable_consumer command. This assignment is symbolic since we've zmalloc
 251          * the struct.
 252          */
 253         lus->tmp_consumer = NULL;
 254
 255         DBG2("UST trace session create successful");
 256
 257         return lus;
 258
 259 error_consumer:
 260         ht_cleanup_push(lus->domain_global.channels);
 261         jul_destroy_domain(&lus->domain_jul);
 262         free(lus);
 263 error:
 264         return NULL;
 265 }
 266
 267 /*
 268  * Allocate and initialize a ust channel data structure.
 269  *
 270  * Return pointer to structure or NULL.
 271  */
 272 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan)
 273 {
 274         struct ltt_ust_channel *luc;
 275
 276         assert(chan);
 277
 278         luc = zmalloc(sizeof(struct ltt_ust_channel));
 279         if (luc == NULL) {
 280                 PERROR("ltt_ust_channel zmalloc");
 281                 goto error;
 282         }
 283
 284         /* Copy UST channel attributes */
 285         luc->attr.overwrite = chan->attr.overwrite;
 286         luc->attr.subbuf_size = chan->attr.subbuf_size;
 287         luc->attr.num_subbuf = chan->attr.num_subbuf;
 288         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 289         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 290         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 291
 292         /* Translate to UST output enum */
 293         switch (luc->attr.output) {
 294         default:
 295                 luc->attr.output = LTTNG_UST_MMAP;
 296                 break;
 297         }
 298
 299         /*
 300          * If we receive an empty string for channel name, it means the
 301          * default channel name is requested.
 302          */
 303         if (chan->name[0] == '\0') {
 304                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 305         } else {
 306                 /* Copy channel name */
 307                 strncpy(luc->name, chan->name, sizeof(luc->name));
 308         }
 309         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 310
 311         /* Init node */
 312         lttng_ht_node_init_str(&luc->node, luc->name);
 313         CDS_INIT_LIST_HEAD(&luc->ctx_list);
 314
 315         /* Alloc hash tables */
 316         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 317         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 318
 319         /* On-disk circular buffer parameters */
 320         luc->tracefile_size = chan->attr.tracefile_size;
 321         luc->tracefile_count = chan->attr.tracefile_count;
 322
 323         DBG2("Trace UST channel %s created", luc->name);
 324
 325 error:
 326         return luc;
 327 }
 328
 329 /*
 330  * Allocate and initialize a ust event. Set name and event type.
 331  *
 332  * Return pointer to structure or NULL.
 333  */
 334 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 335                 struct lttng_filter_bytecode *filter,
 336                 struct lttng_event_exclusion *exclusion)
 337 {
 338         struct ltt_ust_event *lue;
 339
 340         assert(ev);
 341
 342         lue = zmalloc(sizeof(struct ltt_ust_event));
 343         if (lue == NULL) {
 344                 PERROR("ust event zmalloc");
 345                 goto error;
 346         }
 347
 348         switch (ev->type) {
 349         case LTTNG_EVENT_PROBE:
 350                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 351                 break;
 352         case LTTNG_EVENT_FUNCTION:
 353                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 354                 break;
 355         case LTTNG_EVENT_FUNCTION_ENTRY:
 356                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 357                 break;
 358         case LTTNG_EVENT_TRACEPOINT:
 359                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 360                 break;
 361         default:
 362                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 363                 goto error_free_event;
 364         }
 365
 366         /* Copy event name */
 367         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 368         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 369
 370         switch (ev->loglevel_type) {
 371         case LTTNG_EVENT_LOGLEVEL_ALL:
 372                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 373                 lue->attr.loglevel = -1;        /* Force to -1 */
 374                 break;
 375         case LTTNG_EVENT_LOGLEVEL_RANGE:
 376                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 377                 lue->attr.loglevel = ev->loglevel;
 378                 break;
 379         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 380                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 381                 lue->attr.loglevel = ev->loglevel;
 382                 break;
 383         default:
 384                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 385                 goto error_free_event;
 386         }
 387
 388         /* Same layout. */
 389         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 390         lue->exclusion = (struct lttng_event_exclusion *) exclusion;
 391
 392         /* Init node */
 393         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 394
 395         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 396                 lue->attr.name, lue->attr.loglevel_type,
 397                 lue->attr.loglevel);
 398
 399         return lue;
 400
 401 error_free_event:
 402         free(lue);
 403 error:
 404         return NULL;
 405 }
 406
 407 /*
 408  * Allocate and initialize an UST context.
 409  *
 410  * Return pointer to structure or NULL.
 411  */
 412 struct ltt_ust_context *trace_ust_create_context(
 413                 struct lttng_event_context *ctx)
 414 {
 415         struct ltt_ust_context *uctx;
 416         enum lttng_ust_context_type utype;
 417
 418         assert(ctx);
 419
 420         switch (ctx->ctx) {
 421         case LTTNG_EVENT_CONTEXT_VTID:
 422                 utype = LTTNG_UST_CONTEXT_VTID;
 423                 break;
 424         case LTTNG_EVENT_CONTEXT_VPID:
 425                 utype = LTTNG_UST_CONTEXT_VPID;
 426                 break;
 427         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 428                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 429                 break;
 430         case LTTNG_EVENT_CONTEXT_PROCNAME:
 431                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 432                 break;
 433         case LTTNG_EVENT_CONTEXT_IP:
 434                 utype = LTTNG_UST_CONTEXT_IP;
 435                 break;
 436         default:
 437                 ERR("Invalid UST context");
 438                 return NULL;
 439         }
 440
 441         uctx = zmalloc(sizeof(struct ltt_ust_context));
 442         if (uctx == NULL) {
 443                 PERROR("zmalloc ltt_ust_context");
 444                 goto error;
 445         }
 446
 447         uctx->ctx.ctx = utype;
 448         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 449         CDS_INIT_LIST_HEAD(&uctx->list);
 450
 451         return uctx;
 452
 453 error:
 454         return NULL;
 455 }
 456
 457 /*
 458  * RCU safe free context structure.
 459  */
 460 static void destroy_context_rcu(struct rcu_head *head)
 461 {
 462         struct lttng_ht_node_ulong *node =
 463                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 464         struct ltt_ust_context *ctx =
 465                 caa_container_of(node, struct ltt_ust_context, node);
 466
 467         free(ctx);
 468 }
 469
 470 /*
 471  * Cleanup UST context hash table.
 472  */
 473 static void destroy_contexts(struct lttng_ht *ht)
 474 {
 475         int ret;
 476         struct lttng_ht_node_ulong *node;
 477         struct lttng_ht_iter iter;
 478         struct ltt_ust_context *ctx;
 479
 480         assert(ht);
 481
 482         rcu_read_lock();
 483         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 484                 /* Remove from ordered list. */
 485                 ctx = caa_container_of(node, struct ltt_ust_context, node);
 486                 cds_list_del(&ctx->list);
 487                 /* Remove from channel's hash table. */
 488                 ret = lttng_ht_del(ht, &iter);
 489                 if (!ret) {
 490                         call_rcu(&node->head, destroy_context_rcu);
 491                 }
 492         }
 493         rcu_read_unlock();
 494
 495         ht_cleanup_push(ht);
 496 }
 497
 498 /*
 499  * Cleanup ust event structure.
 500  */
 501 void trace_ust_destroy_event(struct ltt_ust_event *event)
 502 {
 503         assert(event);
 504
 505         DBG2("Trace destroy UST event %s", event->attr.name);
 506         free(event->filter);
 507         free(event);
 508 }
 509
 510 /*
 511  * URCU intermediate call to complete destroy event.
 512  */
 513 static void destroy_event_rcu(struct rcu_head *head)
 514 {
 515         struct lttng_ht_node_str *node =
 516                 caa_container_of(head, struct lttng_ht_node_str, head);
 517         struct ltt_ust_event *event =
 518                 caa_container_of(node, struct ltt_ust_event, node);
 519
 520         trace_ust_destroy_event(event);
 521 }
 522
 523 /*
 524  * Cleanup UST events hashtable.
 525  */
 526 static void destroy_events(struct lttng_ht *events)
 527 {
 528         int ret;
 529         struct lttng_ht_node_str *node;
 530         struct lttng_ht_iter iter;
 531
 532         assert(events);
 533
 534         rcu_read_lock();
 535         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 536                 ret = lttng_ht_del(events, &iter);
 537                 assert(!ret);
 538                 call_rcu(&node->head, destroy_event_rcu);
 539         }
 540         rcu_read_unlock();
 541
 542         ht_cleanup_push(events);
 543 }
 544
 545 /*
 546  * Cleanup ust channel structure.
 547  *
 548  * Should _NOT_ be called with RCU read lock held.
 549  */
 550 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 551 {
 552         assert(channel);
 553
 554         DBG2("Trace destroy UST channel %s", channel->name);
 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
 564 /*
 565  * URCU intermediate call to complete destroy channel.
 566  */
 567 static void destroy_channel_rcu(struct rcu_head *head)
 568 {
 569         struct lttng_ht_node_str *node =
 570                 caa_container_of(head, struct lttng_ht_node_str, head);
 571         struct ltt_ust_channel *channel =
 572                 caa_container_of(node, struct ltt_ust_channel, node);
 573
 574         _trace_ust_destroy_channel(channel);
 575 }
 576
 577 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 578 {
 579         call_rcu(&channel->node.head, destroy_channel_rcu);
 580 }
 581
 582 /*
 583  * Remove an UST channel from a channel HT.
 584  */
 585 void trace_ust_delete_channel(struct lttng_ht *ht,
 586                 struct ltt_ust_channel *channel)
 587 {
 588         int ret;
 589         struct lttng_ht_iter iter;
 590
 591         assert(ht);
 592         assert(channel);
 593
 594         iter.iter.node = &channel->node.node;
 595         ret = lttng_ht_del(ht, &iter);
 596         assert(!ret);
 597 }
 598
 599 /*
 600  * Iterate over a hash table containing channels and cleanup safely.
 601  */
 602 static void destroy_channels(struct lttng_ht *channels)
 603 {
 604         int ret;
 605         struct lttng_ht_node_str *node;
 606         struct lttng_ht_iter iter;
 607
 608         assert(channels);
 609
 610         rcu_read_lock();
 611
 612         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 613                 ret = lttng_ht_del(channels, &iter);
 614                 assert(!ret);
 615                 call_rcu(&node->head, destroy_channel_rcu);
 616         }
 617         rcu_read_unlock();
 618
 619         ht_cleanup_push(channels);
 620 }
 621
 622 /*
 623  * Cleanup UST global domain.
 624  */
 625 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 626 {
 627         assert(dom);
 628
 629         destroy_channels(dom->channels);
 630 }
 631
 632 /*
 633  * Cleanup ust session structure
 634  *
 635  * Should *NOT* be called with RCU read-side lock held.
 636  */
 637 void trace_ust_destroy_session(struct ltt_ust_session *session)
 638 {
 639         struct buffer_reg_uid *reg, *sreg;
 640
 641         assert(session);
 642
 643         DBG2("Trace UST destroy session %" PRIu64, session->id);
 644
 645         /* Cleaning up UST domain */
 646         destroy_domain_global(&session->domain_global);
 647         jul_destroy_domain(&session->domain_jul);
 648
 649         /* Cleanup UID buffer registry object(s). */
 650         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 651                         lnode) {
 652                 cds_list_del(&reg->lnode);
 653                 buffer_reg_uid_remove(reg);
 654                 buffer_reg_uid_destroy(reg, session->consumer);
 655         }
 656
 657         consumer_destroy_output(session->consumer);
 658         consumer_destroy_output(session->tmp_consumer);
 659
 660         free(session);
 661 }