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 "trace-ust.h"
  28
  29 /*
  30  * Match function for the events hash table lookup.
  31  *
  32  * Matches by name only. Used by the disable command.
  33  */
  34 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  35                 const void *_key)
  36 {
  37         struct ltt_ust_event *event;
  38         const char *name;
  39
  40         assert(node);
  41         assert(_key);
  42
  43         event = caa_container_of(node, struct ltt_ust_event, node.node);
  44         name = _key;
  45
  46         /* Event name */
  47         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  48                 goto no_match;
  49         }
  50
  51         /* Match */
  52         return 1;
  53
  54 no_match:
  55         return 0;
  56 }
  57
  58 /*
  59  * Match function for the hash table lookup.
  60  *
  61  * It matches an ust event based on three attributes which are the event name,
  62  * the filter bytecode and the loglevel.
  63  */
  64 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  65 {
  66         struct ltt_ust_event *event;
  67         const struct ltt_ust_ht_key *key;
  68
  69         assert(node);
  70         assert(_key);
  71
  72         event = caa_container_of(node, struct ltt_ust_event, node.node);
  73         key = _key;
  74
  75         /* Match the 3 elements of the key: name, filter and loglevel. */
  76
  77         /* Event name */
  78         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  79                 goto no_match;
  80         }
  81
  82         /* Event loglevel. */
  83         if (event->attr.loglevel != key->loglevel) {
  84                 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
  85                                 && key->loglevel == 0 && event->attr.loglevel == -1) {
  86                         /*
  87                          * Match is accepted. This is because on event creation, the
  88                          * loglevel is set to -1 if the event loglevel type is ALL so 0 and
  89                          * -1 are accepted for this loglevel type since 0 is the one set by
  90                          * the API when receiving an enable event.
  91                          */
  92                 } else {
  93                         goto no_match;
  94                 }
  95         }
  96
  97         /* Only one of the filters is NULL, fail. */
  98         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
  99                 goto no_match;
 100         }
 101
 102         if (key->filter && event->filter) {
 103                 /* Both filters exists, check length followed by the bytecode. */
 104                 if (event->filter->len != key->filter->len ||
 105                                 memcmp(event->filter->data, key->filter->data,
 106                                         event->filter->len) != 0) {
 107                         goto no_match;
 108                 }
 109         }
 110
 111         /* Match. */
 112         return 1;
 113
 114 no_match:
 115         return 0;
 116 }
 117
 118 /*
 119  * Find the channel in the hashtable.
 120  */
 121 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 122                 char *name)
 123 {
 124         struct lttng_ht_node_str *node;
 125         struct lttng_ht_iter iter;
 126
 127         rcu_read_lock();
 128         lttng_ht_lookup(ht, (void *)name, &iter);
 129         node = lttng_ht_iter_get_node_str(&iter);
 130         if (node == NULL) {
 131                 rcu_read_unlock();
 132                 goto error;
 133         }
 134         rcu_read_unlock();
 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.
 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, struct lttng_domain *domain)
 185 {
 186         int ret;
 187         struct ltt_ust_session *lus;
 188
 189         /* Allocate a new ltt ust session */
 190         lus = zmalloc(sizeof(struct ltt_ust_session));
 191         if (lus == NULL) {
 192                 PERROR("create ust session zmalloc");
 193                 goto error;
 194         }
 195
 196         /* Init data structure */
 197         lus->id = session_id;
 198         lus->start_trace = 0;
 199
 200         /* Alloc UST domain hash tables */
 201         lus->domain_pid = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 202         lus->domain_exec = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 203
 204         /* Alloc UST global domain channels' HT */
 205         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 206
 207         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 208         if (lus->consumer == NULL) {
 209                 goto error_consumer;
 210         }
 211
 212         /*
 213          * The tmp_consumer stays NULL until a set_consumer_uri command is
 214          * executed. At this point, the consumer should be nullify until an
 215          * enable_consumer command. This assignment is symbolic since we've zmalloc
 216          * the struct.
 217          */
 218         lus->tmp_consumer = NULL;
 219
 220         /* Use the default consumer output which is the tracing session path. */
 221         if (path && strlen(path) > 0) {
 222                 ret = snprintf(lus->consumer->dst.trace_path, PATH_MAX,
 223                                 "%s" DEFAULT_UST_TRACE_DIR, path);
 224                 if (ret < 0) {
 225                         PERROR("snprintf UST consumer trace path");
 226                         goto error_path;
 227                 }
 228
 229                 /* Set session path */
 230                 ret = snprintf(lus->pathname, PATH_MAX, "%s" DEFAULT_UST_TRACE_DIR,
 231                                 path);
 232                 if (ret < 0) {
 233                         PERROR("snprintf kernel traces path");
 234                         goto error_path;
 235                 }
 236         }
 237
 238         DBG2("UST trace session create successful");
 239
 240         return lus;
 241
 242 error_path:
 243         consumer_destroy_output(lus->consumer);
 244 error_consumer:
 245         lttng_ht_destroy(lus->domain_global.channels);
 246         lttng_ht_destroy(lus->domain_exec);
 247         lttng_ht_destroy(lus->domain_pid);
 248         free(lus);
 249 error:
 250         return NULL;
 251 }
 252
 253 /*
 254  * Allocate and initialize a ust channel data structure.
 255  *
 256  * Return pointer to structure or NULL.
 257  */
 258 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 259                 char *path)
 260 {
 261         int ret;
 262         struct ltt_ust_channel *luc;
 263
 264         luc = zmalloc(sizeof(struct ltt_ust_channel));
 265         if (luc == NULL) {
 266                 PERROR("ltt_ust_channel zmalloc");
 267                 goto error;
 268         }
 269
 270         /* Copy UST channel attributes */
 271         luc->attr.overwrite = chan->attr.overwrite;
 272         luc->attr.subbuf_size = chan->attr.subbuf_size;
 273         luc->attr.num_subbuf = chan->attr.num_subbuf;
 274         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 275         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 276         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 277
 278         /* Translate to UST output enum */
 279         switch (luc->attr.output) {
 280         default:
 281                 luc->attr.output = LTTNG_UST_MMAP;
 282                 break;
 283         }
 284
 285         /* Copy channel name */
 286         strncpy(luc->name, chan->name, sizeof(luc->name));
 287         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 288
 289         /* Init node */
 290         lttng_ht_node_init_str(&luc->node, luc->name);
 291         /* Alloc hash tables */
 292         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 293         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 294
 295         /* Set trace output path */
 296         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 297         if (ret < 0) {
 298                 PERROR("asprintf ust create channel");
 299                 goto error_free_channel;
 300         }
 301
 302         DBG2("Trace UST channel %s created", luc->name);
 303
 304         return luc;
 305
 306 error_free_channel:
 307         lttng_ht_destroy(luc->ctx);
 308         lttng_ht_destroy(luc->events);
 309         free(luc);
 310 error:
 311         return NULL;
 312 }
 313
 314 /*
 315  * Allocate and initialize a ust event. Set name and event type.
 316  *
 317  * Return pointer to structure or NULL.
 318  */
 319 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 320                 struct lttng_filter_bytecode *filter)
 321 {
 322         struct ltt_ust_event *lue;
 323
 324         lue = zmalloc(sizeof(struct ltt_ust_event));
 325         if (lue == NULL) {
 326                 PERROR("ust event zmalloc");
 327                 goto error;
 328         }
 329
 330         switch (ev->type) {
 331         case LTTNG_EVENT_PROBE:
 332                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 333                 break;
 334         case LTTNG_EVENT_FUNCTION:
 335                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 336                 break;
 337         case LTTNG_EVENT_FUNCTION_ENTRY:
 338                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 339                 break;
 340         case LTTNG_EVENT_TRACEPOINT:
 341                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 342                 break;
 343         default:
 344                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 345                 goto error_free_event;
 346         }
 347
 348         /* Copy event name */
 349         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 350         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 351
 352         switch (ev->loglevel_type) {
 353         case LTTNG_EVENT_LOGLEVEL_ALL:
 354                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 355                 lue->attr.loglevel = -1;        /* Force to -1 */
 356                 break;
 357         case LTTNG_EVENT_LOGLEVEL_RANGE:
 358                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 359                 lue->attr.loglevel = ev->loglevel;
 360                 break;
 361         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 362                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 363                 lue->attr.loglevel = ev->loglevel;
 364                 break;
 365         default:
 366                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 367                 goto error_free_event;
 368         }
 369
 370         /* Same layout. */
 371         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 372
 373         /* Init node */
 374         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 375
 376         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 377                 lue->attr.name, lue->attr.loglevel_type,
 378                 lue->attr.loglevel);
 379
 380         return lue;
 381
 382 error_free_event:
 383         free(lue);
 384 error:
 385         return NULL;
 386 }
 387
 388 /*
 389  * Allocate and initialize a ust metadata.
 390  *
 391  * Return pointer to structure or NULL.
 392  */
 393 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 394 {
 395         int ret;
 396         struct ltt_ust_metadata *lum;
 397
 398         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 399         if (lum == NULL) {
 400                 PERROR("ust metadata zmalloc");
 401                 goto error;
 402         }
 403
 404         /* Set default attributes */
 405         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 406         lum->attr.subbuf_size = default_get_metadata_subbuf_size();
 407         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 408         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 409         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 410         lum->attr.output = LTTNG_UST_MMAP;
 411
 412         lum->handle = -1;
 413         /* Set metadata trace path */
 414         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 415         if (ret < 0) {
 416                 PERROR("asprintf ust metadata");
 417                 goto error_free_metadata;
 418         }
 419
 420         return lum;
 421
 422 error_free_metadata:
 423         free(lum);
 424 error:
 425         return NULL;
 426 }
 427
 428 /*
 429  * Allocate and initialize an UST context.
 430  *
 431  * Return pointer to structure or NULL.
 432  */
 433 struct ltt_ust_context *trace_ust_create_context(
 434                 struct lttng_event_context *ctx)
 435 {
 436         struct ltt_ust_context *uctx;
 437         enum lttng_ust_context_type utype;
 438
 439         switch (ctx->ctx) {
 440         case LTTNG_EVENT_CONTEXT_VTID:
 441                 utype = LTTNG_UST_CONTEXT_VTID;
 442                 break;
 443         case LTTNG_EVENT_CONTEXT_VPID:
 444                 utype = LTTNG_UST_CONTEXT_VPID;
 445                 break;
 446         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 447                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 448                 break;
 449         case LTTNG_EVENT_CONTEXT_PROCNAME:
 450                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 451                 break;
 452         default:
 453                 ERR("Invalid UST context");
 454                 return NULL;
 455         }
 456
 457         uctx = zmalloc(sizeof(struct ltt_ust_context));
 458         if (uctx == NULL) {
 459                 PERROR("zmalloc ltt_ust_context");
 460                 goto error;
 461         }
 462
 463         uctx->ctx.ctx = utype;
 464         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 465
 466         return uctx;
 467
 468 error:
 469         return NULL;
 470 }
 471
 472 /*
 473  * RCU safe free context structure.
 474  */
 475 static void destroy_context_rcu(struct rcu_head *head)
 476 {
 477         struct lttng_ht_node_ulong *node =
 478                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 479         struct ltt_ust_context *ctx =
 480                 caa_container_of(node, struct ltt_ust_context, node);
 481
 482         free(ctx);
 483 }
 484
 485 /*
 486  * Cleanup UST context hash table.
 487  */
 488 static void destroy_contexts(struct lttng_ht *ht)
 489 {
 490         int ret;
 491         struct lttng_ht_node_ulong *node;
 492         struct lttng_ht_iter iter;
 493
 494         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 495                 ret = lttng_ht_del(ht, &iter);
 496                 if (!ret) {
 497                         call_rcu(&node->head, destroy_context_rcu);
 498                 }
 499         }
 500
 501         lttng_ht_destroy(ht);
 502 }
 503
 504 /*
 505  * Cleanup ust event structure.
 506  */
 507 void trace_ust_destroy_event(struct ltt_ust_event *event)
 508 {
 509         DBG2("Trace destroy UST event %s", event->attr.name);
 510         free(event->filter);
 511         free(event);
 512 }
 513
 514 /*
 515  * URCU intermediate call to complete destroy event.
 516  */
 517 static void destroy_event_rcu(struct rcu_head *head)
 518 {
 519         struct lttng_ht_node_str *node =
 520                 caa_container_of(head, struct lttng_ht_node_str, head);
 521         struct ltt_ust_event *event =
 522                 caa_container_of(node, struct ltt_ust_event, node);
 523
 524         trace_ust_destroy_event(event);
 525 }
 526
 527 /*
 528  * Cleanup UST events hashtable.
 529  */
 530 static void destroy_events(struct lttng_ht *events)
 531 {
 532         int ret;
 533         struct lttng_ht_node_str *node;
 534         struct lttng_ht_iter iter;
 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         DBG2("Trace destroy UST channel %s", channel->name);
 551
 552         rcu_read_lock();
 553
 554         /* Destroying all events of the channel */
 555         destroy_events(channel->events);
 556         /* Destroying all context of the channel */
 557         destroy_contexts(channel->ctx);
 558
 559         free(channel);
 560
 561         rcu_read_unlock();
 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 /*
 578  * Cleanup ust metadata structure.
 579  */
 580 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 581 {
 582         if (!metadata->handle) {
 583                 return;
 584         }
 585         DBG2("Trace UST destroy metadata %d", metadata->handle);
 586         free(metadata);
 587 }
 588
 589 /*
 590  * Iterate over a hash table containing channels and cleanup safely.
 591  */
 592 static void destroy_channels(struct lttng_ht *channels)
 593 {
 594         int ret;
 595         struct lttng_ht_node_str *node;
 596         struct lttng_ht_iter iter;
 597
 598         rcu_read_lock();
 599
 600         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 601                 ret = lttng_ht_del(channels, &iter);
 602                 assert(!ret);
 603                 call_rcu(&node->head, destroy_channel_rcu);
 604         }
 605
 606         lttng_ht_destroy(channels);
 607
 608         rcu_read_unlock();
 609 }
 610
 611 /*
 612  * Cleanup UST pid domain.
 613  */
 614 static void destroy_domain_pid(struct lttng_ht *ht)
 615 {
 616         int ret;
 617         struct lttng_ht_iter iter;
 618         struct ltt_ust_domain_pid *dpid;
 619
 620         cds_lfht_for_each_entry(ht->ht, &iter.iter, dpid, node.node) {
 621                 ret = lttng_ht_del(ht , &iter);
 622                 assert(!ret);
 623                 destroy_channels(dpid->channels);
 624         }
 625
 626         lttng_ht_destroy(ht);
 627 }
 628
 629 /*
 630  * Cleanup UST exec name domain.
 631  */
 632 static void destroy_domain_exec(struct lttng_ht *ht)
 633 {
 634         int ret;
 635         struct lttng_ht_iter iter;
 636         struct ltt_ust_domain_exec *dexec;
 637
 638         cds_lfht_for_each_entry(ht->ht, &iter.iter, dexec, node.node) {
 639                 ret = lttng_ht_del(ht , &iter);
 640                 assert(!ret);
 641                 destroy_channels(dexec->channels);
 642         }
 643
 644         lttng_ht_destroy(ht);
 645 }
 646
 647 /*
 648  * Cleanup UST global domain.
 649  */
 650 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 651 {
 652         destroy_channels(dom->channels);
 653 }
 654
 655 /*
 656  * Cleanup ust session structure
 657  */
 658 void trace_ust_destroy_session(struct ltt_ust_session *session)
 659 {
 660         /* Extra protection */
 661         if (session == NULL) {
 662                 return;
 663         }
 664
 665         rcu_read_lock();
 666
 667         DBG2("Trace UST destroy session %u", session->id);
 668
 669         /* Cleaning up UST domain */
 670         destroy_domain_global(&session->domain_global);
 671         destroy_domain_pid(session->domain_pid);
 672         destroy_domain_exec(session->domain_exec);
 673
 674         consumer_destroy_output(session->consumer);
 675         consumer_destroy_output(session->tmp_consumer);
 676
 677         free(session);
 678
 679         rcu_read_unlock();
 680 }