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
  30 /*
  31  * Match function for the events hash table lookup.
  32  *
  33  * Matches by name only. Used by the disable command.
  34  */
  35 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
  36                 const void *_key)
  37 {
  38         struct ltt_ust_event *event;
  39         const char *name;
  40
  41         assert(node);
  42         assert(_key);
  43
  44         event = caa_container_of(node, struct ltt_ust_event, node.node);
  45         name = _key;
  46
  47         /* Event name */
  48         if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
  49                 goto no_match;
  50         }
  51
  52         /* Match */
  53         return 1;
  54
  55 no_match:
  56         return 0;
  57 }
  58
  59 /*
  60  * Match function for the hash table lookup.
  61  *
  62  * It matches an ust event based on three attributes which are the event name,
  63  * the filter bytecode and the loglevel.
  64  */
  65 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
  66 {
  67         struct ltt_ust_event *event;
  68         const struct ltt_ust_ht_key *key;
  69
  70         assert(node);
  71         assert(_key);
  72
  73         event = caa_container_of(node, struct ltt_ust_event, node.node);
  74         key = _key;
  75
  76         /* Match the 3 elements of the key: name, filter and loglevel. */
  77
  78         /* Event name */
  79         if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
  80                 goto no_match;
  81         }
  82
  83         /* Event loglevel. */
  84         if (event->attr.loglevel != key->loglevel) {
  85                 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
  86                                 && key->loglevel == 0 && event->attr.loglevel == -1) {
  87                         /*
  88                          * Match is accepted. This is because on event creation, the
  89                          * loglevel is set to -1 if the event loglevel type is ALL so 0 and
  90                          * -1 are accepted for this loglevel type since 0 is the one set by
  91                          * the API when receiving an enable event.
  92                          */
  93                 } else {
  94                         goto no_match;
  95                 }
  96         }
  97
  98         /* Only one of the filters is NULL, fail. */
  99         if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
 100                 goto no_match;
 101         }
 102
 103         if (key->filter && event->filter) {
 104                 /* Both filters exists, check length followed by the bytecode. */
 105                 if (event->filter->len != key->filter->len ||
 106                                 memcmp(event->filter->data, key->filter->data,
 107                                         event->filter->len) != 0) {
 108                         goto no_match;
 109                 }
 110         }
 111
 112         /* Match. */
 113         return 1;
 114
 115 no_match:
 116         return 0;
 117 }
 118
 119 /*
 120  * Find the channel in the hashtable and return channel pointer. RCU read side
 121  * lock MUST be acquired before calling this.
 122  */
 123 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
 124                 char *name)
 125 {
 126         struct lttng_ht_node_str *node;
 127         struct lttng_ht_iter iter;
 128
 129         lttng_ht_lookup(ht, (void *)name, &iter);
 130         node = lttng_ht_iter_get_node_str(&iter);
 131         if (node == NULL) {
 132                 goto error;
 133         }
 134
 135         DBG2("Trace UST channel %s found by name", name);
 136
 137         return caa_container_of(node, struct ltt_ust_channel, node);
 138
 139 error:
 140         DBG2("Trace UST channel %s not found by name", name);
 141         return NULL;
 142 }
 143
 144 /*
 145  * Find the event in the hashtable and return event pointer. RCU read side lock
 146  * MUST be acquired before calling this.
 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(unsigned int session_id)
 184 {
 185         struct ltt_ust_session *lus;
 186
 187         /* Allocate a new ltt ust session */
 188         lus = zmalloc(sizeof(struct ltt_ust_session));
 189         if (lus == NULL) {
 190                 PERROR("create ust session zmalloc");
 191                 goto error;
 192         }
 193
 194         /* Init data structure */
 195         lus->id = session_id;
 196         lus->start_trace = 0;
 197
 198         /*
 199          * Default buffer type. This can be changed through an enable channel
 200          * requesting a different type. Note that this can only be changed once
 201          * during the session lifetime which is at the first enable channel and
 202          * only before start. The flag buffer_type_changed indicates the status.
 203          */
 204         lus->buffer_type = LTTNG_BUFFER_PER_PID;
 205         /* Once set to 1, the buffer_type is immutable for the session. */
 206         lus->buffer_type_changed = 0;
 207         /* Init it in case it get used after allocation. */
 208         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 209
 210         /* Alloc UST global domain channels' HT */
 211         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 212
 213         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 214         if (lus->consumer == NULL) {
 215                 goto error_consumer;
 216         }
 217
 218         /*
 219          * The tmp_consumer stays NULL until a set_consumer_uri command is
 220          * executed. At this point, the consumer should be nullify until an
 221          * enable_consumer command. This assignment is symbolic since we've zmalloc
 222          * the struct.
 223          */
 224         lus->tmp_consumer = NULL;
 225
 226         DBG2("UST trace session create successful");
 227
 228         return lus;
 229
 230 error_consumer:
 231         lttng_ht_destroy(lus->domain_global.channels);
 232         free(lus);
 233 error:
 234         return NULL;
 235 }
 236
 237 /*
 238  * Allocate and initialize a ust channel data structure.
 239  *
 240  * Return pointer to structure or NULL.
 241  */
 242 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan)
 243 {
 244         struct ltt_ust_channel *luc;
 245
 246         assert(chan);
 247
 248         luc = zmalloc(sizeof(struct ltt_ust_channel));
 249         if (luc == NULL) {
 250                 PERROR("ltt_ust_channel zmalloc");
 251                 goto error;
 252         }
 253
 254         /* Copy UST channel attributes */
 255         luc->attr.overwrite = chan->attr.overwrite;
 256         luc->attr.subbuf_size = chan->attr.subbuf_size;
 257         luc->attr.num_subbuf = chan->attr.num_subbuf;
 258         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 259         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 260         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 261
 262         /* Translate to UST output enum */
 263         switch (luc->attr.output) {
 264         default:
 265                 luc->attr.output = LTTNG_UST_MMAP;
 266                 break;
 267         }
 268
 269         /* Copy channel name */
 270         strncpy(luc->name, chan->name, sizeof(luc->name));
 271         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 272
 273         /* Init node */
 274         lttng_ht_node_init_str(&luc->node, luc->name);
 275         /* Alloc hash tables */
 276         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 277         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 278
 279         /* On-disk circular buffer parameters */
 280         luc->tracefile_size = chan->attr.tracefile_size;
 281         luc->tracefile_count = chan->attr.tracefile_count;
 282
 283         DBG2("Trace UST channel %s created", luc->name);
 284
 285 error:
 286         return luc;
 287 }
 288
 289 /*
 290  * Allocate and initialize a ust event. Set name and event type.
 291  *
 292  * Return pointer to structure or NULL.
 293  */
 294 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 295                 struct lttng_filter_bytecode *filter)
 296 {
 297         struct ltt_ust_event *lue;
 298
 299         assert(ev);
 300
 301         lue = zmalloc(sizeof(struct ltt_ust_event));
 302         if (lue == NULL) {
 303                 PERROR("ust event zmalloc");
 304                 goto error;
 305         }
 306
 307         switch (ev->type) {
 308         case LTTNG_EVENT_PROBE:
 309                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 310                 break;
 311         case LTTNG_EVENT_FUNCTION:
 312                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 313                 break;
 314         case LTTNG_EVENT_FUNCTION_ENTRY:
 315                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 316                 break;
 317         case LTTNG_EVENT_TRACEPOINT:
 318                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 319                 break;
 320         default:
 321                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 322                 goto error_free_event;
 323         }
 324
 325         /* Copy event name */
 326         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 327         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 328
 329         switch (ev->loglevel_type) {
 330         case LTTNG_EVENT_LOGLEVEL_ALL:
 331                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 332                 lue->attr.loglevel = -1;        /* Force to -1 */
 333                 break;
 334         case LTTNG_EVENT_LOGLEVEL_RANGE:
 335                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 336                 lue->attr.loglevel = ev->loglevel;
 337                 break;
 338         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 339                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 340                 lue->attr.loglevel = ev->loglevel;
 341                 break;
 342         default:
 343                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 344                 goto error_free_event;
 345         }
 346
 347         /* Same layout. */
 348         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 349
 350         /* Init node */
 351         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 352
 353         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 354                 lue->attr.name, lue->attr.loglevel_type,
 355                 lue->attr.loglevel);
 356
 357         return lue;
 358
 359 error_free_event:
 360         free(lue);
 361 error:
 362         return NULL;
 363 }
 364
 365 /*
 366  * Allocate and initialize a ust metadata.
 367  *
 368  * Return pointer to structure or NULL.
 369  */
 370 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 371 {
 372         int ret;
 373         struct ltt_ust_metadata *lum;
 374
 375         assert(path);
 376
 377         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 378         if (lum == NULL) {
 379                 PERROR("ust metadata zmalloc");
 380                 goto error;
 381         }
 382
 383         /* Set default attributes */
 384         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 385         lum->attr.subbuf_size = default_get_metadata_subbuf_size();
 386         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 387         lum->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 388         lum->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 389         lum->attr.output = LTTNG_UST_MMAP;
 390
 391         lum->handle = -1;
 392         /* Set metadata trace path */
 393         ret = snprintf(lum->pathname, PATH_MAX, "%s/" DEFAULT_METADATA_NAME, path);
 394         if (ret < 0) {
 395                 PERROR("asprintf ust metadata");
 396                 goto error_free_metadata;
 397         }
 398
 399         return lum;
 400
 401 error_free_metadata:
 402         free(lum);
 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         default:
 434                 ERR("Invalid UST context");
 435                 return NULL;
 436         }
 437
 438         uctx = zmalloc(sizeof(struct ltt_ust_context));
 439         if (uctx == NULL) {
 440                 PERROR("zmalloc ltt_ust_context");
 441                 goto error;
 442         }
 443
 444         uctx->ctx.ctx = utype;
 445         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 446
 447         return uctx;
 448
 449 error:
 450         return NULL;
 451 }
 452
 453 /*
 454  * RCU safe free context structure.
 455  */
 456 static void destroy_context_rcu(struct rcu_head *head)
 457 {
 458         struct lttng_ht_node_ulong *node =
 459                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 460         struct ltt_ust_context *ctx =
 461                 caa_container_of(node, struct ltt_ust_context, node);
 462
 463         free(ctx);
 464 }
 465
 466 /*
 467  * Cleanup UST context hash table.
 468  */
 469 static void destroy_contexts(struct lttng_ht *ht)
 470 {
 471         int ret;
 472         struct lttng_ht_node_ulong *node;
 473         struct lttng_ht_iter iter;
 474
 475         assert(ht);
 476
 477         rcu_read_lock();
 478         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 479                 ret = lttng_ht_del(ht, &iter);
 480                 if (!ret) {
 481                         call_rcu(&node->head, destroy_context_rcu);
 482                 }
 483         }
 484         rcu_read_unlock();
 485
 486         lttng_ht_destroy(ht);
 487 }
 488
 489 /*
 490  * Cleanup ust event structure.
 491  */
 492 void trace_ust_destroy_event(struct ltt_ust_event *event)
 493 {
 494         assert(event);
 495
 496         DBG2("Trace destroy UST event %s", event->attr.name);
 497         free(event->filter);
 498         free(event);
 499 }
 500
 501 /*
 502  * URCU intermediate call to complete destroy event.
 503  */
 504 static void destroy_event_rcu(struct rcu_head *head)
 505 {
 506         struct lttng_ht_node_str *node =
 507                 caa_container_of(head, struct lttng_ht_node_str, head);
 508         struct ltt_ust_event *event =
 509                 caa_container_of(node, struct ltt_ust_event, node);
 510
 511         trace_ust_destroy_event(event);
 512 }
 513
 514 /*
 515  * Cleanup UST events hashtable.
 516  */
 517 static void destroy_events(struct lttng_ht *events)
 518 {
 519         int ret;
 520         struct lttng_ht_node_str *node;
 521         struct lttng_ht_iter iter;
 522
 523         assert(events);
 524
 525         rcu_read_lock();
 526         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 527                 ret = lttng_ht_del(events, &iter);
 528                 assert(!ret);
 529                 call_rcu(&node->head, destroy_event_rcu);
 530         }
 531         rcu_read_unlock();
 532
 533         lttng_ht_destroy(events);
 534 }
 535
 536 /*
 537  * Cleanup ust channel structure.
 538  *
 539  * Should _NOT_ be called with RCU read lock held.
 540  */
 541 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 542 {
 543         assert(channel);
 544
 545         DBG2("Trace destroy UST channel %s", channel->name);
 546
 547         /* Destroying all events of the channel */
 548         destroy_events(channel->events);
 549         /* Destroying all context of the channel */
 550         destroy_contexts(channel->ctx);
 551
 552         free(channel);
 553 }
 554
 555 /*
 556  * URCU intermediate call to complete destroy channel.
 557  */
 558 static void destroy_channel_rcu(struct rcu_head *head)
 559 {
 560         struct lttng_ht_node_str *node =
 561                 caa_container_of(head, struct lttng_ht_node_str, head);
 562         struct ltt_ust_channel *channel =
 563                 caa_container_of(node, struct ltt_ust_channel, node);
 564
 565         _trace_ust_destroy_channel(channel);
 566 }
 567
 568 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 569 {
 570         call_rcu(&channel->node.head, destroy_channel_rcu);
 571 }
 572
 573 /*
 574  * Cleanup ust metadata structure.
 575  */
 576 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 577 {
 578         assert(metadata);
 579
 580         if (!metadata->handle) {
 581                 return;
 582         }
 583         DBG2("Trace UST destroy metadata %d", metadata->handle);
 584         free(metadata);
 585 }
 586
 587 /*
 588  * Iterate over a hash table containing channels and cleanup safely.
 589  */
 590 static void destroy_channels(struct lttng_ht *channels)
 591 {
 592         int ret;
 593         struct lttng_ht_node_str *node;
 594         struct lttng_ht_iter iter;
 595
 596         assert(channels);
 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         rcu_read_unlock();
 606
 607         lttng_ht_destroy(channels);
 608 }
 609
 610 /*
 611  * Cleanup UST global domain.
 612  */
 613 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 614 {
 615         assert(dom);
 616
 617         destroy_channels(dom->channels);
 618 }
 619
 620 /*
 621  * Cleanup ust session structure
 622  *
 623  * Should *NOT* be called with RCU read-side lock held.
 624  */
 625 void trace_ust_destroy_session(struct ltt_ust_session *session)
 626 {
 627         struct buffer_reg_uid *reg, *sreg;
 628
 629         assert(session);
 630
 631         DBG2("Trace UST destroy session %u", session->id);
 632
 633         /* Cleaning up UST domain */
 634         destroy_domain_global(&session->domain_global);
 635
 636         /* Cleanup UID buffer registry object(s). */
 637         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 638                         lnode) {
 639                 cds_list_del(&reg->lnode);
 640                 buffer_reg_uid_remove(reg);
 641                 buffer_reg_uid_destroy(reg, session->consumer);
 642         }
 643
 644         consumer_destroy_output(session->consumer);
 645         consumer_destroy_output(session->tmp_consumer);
 646
 647         free(session);
 648 }