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