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 3 elements of the key: name, filter and loglevel. */
  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         /* Match. */
 115         return 1;
 116
 117 no_match:
 118         return 0;
 119 }
 120
 121 /*
 122  * Find the channel in the hashtable and return channel pointer. RCU read side
 123  * lock MUST be acquired before calling this.
 124  */
 125 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 126                 char *name)
 127 {
 128         struct lttng_ht_node_str *node;
 129         struct lttng_ht_iter iter;
 130
 131         /*
 132          * If we receive an empty string for channel name, it means the
 133          * default channel name is requested.
 134          */
 135         if (name[0] == '\0')
 136                 name = DEFAULT_CHANNEL_NAME;
 137
 138         lttng_ht_lookup(ht, (void *)name, &iter);
 139         node = lttng_ht_iter_get_node_str(&iter);
 140         if (node == NULL) {
 141                 goto error;
 142         }
 143
 144         DBG2("Trace UST channel %s found by name", name);
 145
 146         return caa_container_of(node, struct ltt_ust_channel, node);
 147
 148 error:
 149         DBG2("Trace UST channel %s not found by name", name);
 150         return NULL;
 151 }
 152
 153 /*
 154  * Find the event in the hashtable and return event pointer. RCU read side lock
 155  * MUST be acquired before calling this.
 156  */
 157 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 158                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 159 {
 160         struct lttng_ht_node_str *node;
 161         struct lttng_ht_iter iter;
 162         struct ltt_ust_ht_key key;
 163
 164         assert(name);
 165         assert(ht);
 166
 167         key.name = name;
 168         key.filter = filter;
 169         key.loglevel = loglevel;
 170
 171         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 172                         trace_ust_ht_match_event, &key, &iter.iter);
 173         node = lttng_ht_iter_get_node_str(&iter);
 174         if (node == NULL) {
 175                 goto error;
 176         }
 177
 178         DBG2("Trace UST event %s found", key.name);
 179
 180         return caa_container_of(node, struct ltt_ust_event, node);
 181
 182 error:
 183         DBG2("Trace UST event %s NOT found", key.name);
 184         return NULL;
 185 }
 186
 187 /*
 188  * Allocate and initialize a ust session data structure.
 189  *
 190  * Return pointer to structure or NULL.
 191  */
 192 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 193 {
 194         struct ltt_ust_session *lus;
 195
 196         /* Allocate a new ltt ust session */
 197         lus = zmalloc(sizeof(struct ltt_ust_session));
 198         if (lus == NULL) {
 199                 PERROR("create ust session zmalloc");
 200                 goto error;
 201         }
 202
 203         /* Init data structure */
 204         lus->id = session_id;
 205         lus->start_trace = 0;
 206
 207         /*
 208          * Default buffer type. This can be changed through an enable channel
 209          * requesting a different type. Note that this can only be changed once
 210          * during the session lifetime which is at the first enable channel and
 211          * only before start. The flag buffer_type_changed indicates the status.
 212          */
 213         lus->buffer_type = LTTNG_BUFFER_PER_UID;
 214         /* Once set to 1, the buffer_type is immutable for the session. */
 215         lus->buffer_type_changed = 0;
 216         /* Init it in case it get used after allocation. */
 217         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 218
 219         /* Alloc UST global domain channels' HT */
 220         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 221
 222         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 223         if (lus->consumer == NULL) {
 224                 goto error_consumer;
 225         }
 226
 227         /*
 228          * The tmp_consumer stays NULL until a set_consumer_uri command is
 229          * executed. At this point, the consumer should be nullify until an
 230          * enable_consumer command. This assignment is symbolic since we've zmalloc
 231          * the struct.
 232          */
 233         lus->tmp_consumer = NULL;
 234
 235         DBG2("UST trace session create successful");
 236
 237         return lus;
 238
 239 error_consumer:
 240         ht_cleanup_push(lus->domain_global.channels);
 241         free(lus);
 242 error:
 243         return NULL;
 244 }
 245
 246 /*
 247  * Allocate and initialize a ust channel data structure.
 248  *
 249  * Return pointer to structure or NULL.
 250  */
 251 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan)
 252 {
 253         struct ltt_ust_channel *luc;
 254
 255         assert(chan);
 256
 257         luc = zmalloc(sizeof(struct ltt_ust_channel));
 258         if (luc == NULL) {
 259                 PERROR("ltt_ust_channel zmalloc");
 260                 goto error;
 261         }
 262
 263         /* Copy UST channel attributes */
 264         luc->attr.overwrite = chan->attr.overwrite;
 265         luc->attr.subbuf_size = chan->attr.subbuf_size;
 266         luc->attr.num_subbuf = chan->attr.num_subbuf;
 267         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 268         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 269         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 270
 271         /* Translate to UST output enum */
 272         switch (luc->attr.output) {
 273         default:
 274                 luc->attr.output = LTTNG_UST_MMAP;
 275                 break;
 276         }
 277
 278         /*
 279          * If we receive an empty string for channel name, it means the
 280          * default channel name is requested.
 281          */
 282         if (chan->name[0] == '\0') {
 283                 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
 284         } else {
 285                 /* Copy channel name */
 286                 strncpy(luc->name, chan->name, sizeof(luc->name));
 287         }
 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_METADATA_SWITCH_TIMER;
 405         lum->attr.read_timer_interval = DEFAULT_METADATA_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         case LTTNG_EVENT_CONTEXT_IP:
 451                 utype = LTTNG_UST_CONTEXT_IP;
 452                 break;
 453         default:
 454                 ERR("Invalid UST context");
 455                 return NULL;
 456         }
 457
 458         uctx = zmalloc(sizeof(struct ltt_ust_context));
 459         if (uctx == NULL) {
 460                 PERROR("zmalloc ltt_ust_context");
 461                 goto error;
 462         }
 463
 464         uctx->ctx.ctx = utype;
 465         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 466
 467         return uctx;
 468
 469 error:
 470         return NULL;
 471 }
 472
 473 /*
 474  * RCU safe free context structure.
 475  */
 476 static void destroy_context_rcu(struct rcu_head *head)
 477 {
 478         struct lttng_ht_node_ulong *node =
 479                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 480         struct ltt_ust_context *ctx =
 481                 caa_container_of(node, struct ltt_ust_context, node);
 482
 483         free(ctx);
 484 }
 485
 486 /*
 487  * Cleanup UST context hash table.
 488  */
 489 static void destroy_contexts(struct lttng_ht *ht)
 490 {
 491         int ret;
 492         struct lttng_ht_node_ulong *node;
 493         struct lttng_ht_iter iter;
 494
 495         assert(ht);
 496
 497         rcu_read_lock();
 498         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 499                 ret = lttng_ht_del(ht, &iter);
 500                 if (!ret) {
 501                         call_rcu(&node->head, destroy_context_rcu);
 502                 }
 503         }
 504         rcu_read_unlock();
 505
 506         ht_cleanup_push(ht);
 507 }
 508
 509 /*
 510  * Cleanup ust event structure.
 511  */
 512 void trace_ust_destroy_event(struct ltt_ust_event *event)
 513 {
 514         assert(event);
 515
 516         DBG2("Trace destroy UST event %s", event->attr.name);
 517         free(event->filter);
 518         free(event);
 519 }
 520
 521 /*
 522  * URCU intermediate call to complete destroy event.
 523  */
 524 static void destroy_event_rcu(struct rcu_head *head)
 525 {
 526         struct lttng_ht_node_str *node =
 527                 caa_container_of(head, struct lttng_ht_node_str, head);
 528         struct ltt_ust_event *event =
 529                 caa_container_of(node, struct ltt_ust_event, node);
 530
 531         trace_ust_destroy_event(event);
 532 }
 533
 534 /*
 535  * Cleanup UST events hashtable.
 536  */
 537 static void destroy_events(struct lttng_ht *events)
 538 {
 539         int ret;
 540         struct lttng_ht_node_str *node;
 541         struct lttng_ht_iter iter;
 542
 543         assert(events);
 544
 545         rcu_read_lock();
 546         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 547                 ret = lttng_ht_del(events, &iter);
 548                 assert(!ret);
 549                 call_rcu(&node->head, destroy_event_rcu);
 550         }
 551         rcu_read_unlock();
 552
 553         ht_cleanup_push(events);
 554 }
 555
 556 /*
 557  * Cleanup ust channel structure.
 558  *
 559  * Should _NOT_ be called with RCU read lock held.
 560  */
 561 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 562 {
 563         assert(channel);
 564
 565         DBG2("Trace destroy UST channel %s", channel->name);
 566
 567         /* Destroying all events of the channel */
 568         destroy_events(channel->events);
 569         /* Destroying all context of the channel */
 570         destroy_contexts(channel->ctx);
 571
 572         free(channel);
 573 }
 574
 575 /*
 576  * URCU intermediate call to complete destroy channel.
 577  */
 578 static void destroy_channel_rcu(struct rcu_head *head)
 579 {
 580         struct lttng_ht_node_str *node =
 581                 caa_container_of(head, struct lttng_ht_node_str, head);
 582         struct ltt_ust_channel *channel =
 583                 caa_container_of(node, struct ltt_ust_channel, node);
 584
 585         _trace_ust_destroy_channel(channel);
 586 }
 587
 588 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 589 {
 590         call_rcu(&channel->node.head, destroy_channel_rcu);
 591 }
 592
 593 /*
 594  * Remove an UST channel from a channel HT.
 595  */
 596 void trace_ust_delete_channel(struct lttng_ht *ht,
 597                 struct ltt_ust_channel *channel)
 598 {
 599         int ret;
 600         struct lttng_ht_iter iter;
 601
 602         assert(ht);
 603         assert(channel);
 604
 605         iter.iter.node = &channel->node.node;
 606         ret = lttng_ht_del(ht, &iter);
 607         assert(!ret);
 608 }
 609
 610 /*
 611  * Cleanup ust metadata structure.
 612  */
 613 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 614 {
 615         assert(metadata);
 616
 617         if (!metadata->handle) {
 618                 return;
 619         }
 620         DBG2("Trace UST destroy metadata %d", metadata->handle);
 621         free(metadata);
 622 }
 623
 624 /*
 625  * Iterate over a hash table containing channels and cleanup safely.
 626  */
 627 static void destroy_channels(struct lttng_ht *channels)
 628 {
 629         int ret;
 630         struct lttng_ht_node_str *node;
 631         struct lttng_ht_iter iter;
 632
 633         assert(channels);
 634
 635         rcu_read_lock();
 636
 637         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 638                 ret = lttng_ht_del(channels, &iter);
 639                 assert(!ret);
 640                 call_rcu(&node->head, destroy_channel_rcu);
 641         }
 642         rcu_read_unlock();
 643
 644         ht_cleanup_push(channels);
 645 }
 646
 647 /*
 648  * Cleanup UST global domain.
 649  */
 650 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 651 {
 652         assert(dom);
 653
 654         destroy_channels(dom->channels);
 655 }
 656
 657 /*
 658  * Cleanup ust session structure
 659  *
 660  * Should *NOT* be called with RCU read-side lock held.
 661  */
 662 void trace_ust_destroy_session(struct ltt_ust_session *session)
 663 {
 664         struct buffer_reg_uid *reg, *sreg;
 665
 666         assert(session);
 667
 668         DBG2("Trace UST destroy session %" PRIu64, session->id);
 669
 670         /* Cleaning up UST domain */
 671         destroy_domain_global(&session->domain_global);
 672
 673         /* Cleanup UID buffer registry object(s). */
 674         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 675                         lnode) {
 676                 cds_list_del(&reg->lnode);
 677                 buffer_reg_uid_remove(reg);
 678                 buffer_reg_uid_destroy(reg, session->consumer);
 679         }
 680
 681         consumer_destroy_output(session->consumer);
 682         consumer_destroy_output(session->tmp_consumer);
 683
 684         free(session);
 685 }