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         lttng_ht_lookup(ht, (void *)name, &iter);
 132         node = lttng_ht_iter_get_node_str(&iter);
 133         if (node == NULL) {
 134                 goto error;
 135         }
 136
 137         DBG2("Trace UST channel %s found by name", name);
 138
 139         return caa_container_of(node, struct ltt_ust_channel, node);
 140
 141 error:
 142         DBG2("Trace UST channel %s not found by name", name);
 143         return NULL;
 144 }
 145
 146 /*
 147  * Find the event in the hashtable and return event pointer. RCU read side lock
 148  * MUST be acquired before calling this.
 149  */
 150 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
 151                 char *name, struct lttng_filter_bytecode *filter, int loglevel)
 152 {
 153         struct lttng_ht_node_str *node;
 154         struct lttng_ht_iter iter;
 155         struct ltt_ust_ht_key key;
 156
 157         assert(name);
 158         assert(ht);
 159
 160         key.name = name;
 161         key.filter = filter;
 162         key.loglevel = loglevel;
 163
 164         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
 165                         trace_ust_ht_match_event, &key, &iter.iter);
 166         node = lttng_ht_iter_get_node_str(&iter);
 167         if (node == NULL) {
 168                 goto error;
 169         }
 170
 171         DBG2("Trace UST event %s found", key.name);
 172
 173         return caa_container_of(node, struct ltt_ust_event, node);
 174
 175 error:
 176         DBG2("Trace UST event %s NOT found", key.name);
 177         return NULL;
 178 }
 179
 180 /*
 181  * Allocate and initialize a ust session data structure.
 182  *
 183  * Return pointer to structure or NULL.
 184  */
 185 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
 186 {
 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         /*
 201          * Default buffer type. This can be changed through an enable channel
 202          * requesting a different type. Note that this can only be changed once
 203          * during the session lifetime which is at the first enable channel and
 204          * only before start. The flag buffer_type_changed indicates the status.
 205          */
 206         lus->buffer_type = LTTNG_BUFFER_PER_PID;
 207         /* Once set to 1, the buffer_type is immutable for the session. */
 208         lus->buffer_type_changed = 0;
 209         /* Init it in case it get used after allocation. */
 210         CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
 211
 212         /* Alloc UST global domain channels' HT */
 213         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 214
 215         lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 216         if (lus->consumer == NULL) {
 217                 goto error_consumer;
 218         }
 219
 220         /*
 221          * The tmp_consumer stays NULL until a set_consumer_uri command is
 222          * executed. At this point, the consumer should be nullify until an
 223          * enable_consumer command. This assignment is symbolic since we've zmalloc
 224          * the struct.
 225          */
 226         lus->tmp_consumer = NULL;
 227
 228         DBG2("UST trace session create successful");
 229
 230         return lus;
 231
 232 error_consumer:
 233         ht_cleanup_push(lus->domain_global.channels);
 234         free(lus);
 235 error:
 236         return NULL;
 237 }
 238
 239 /*
 240  * Allocate and initialize a ust channel data structure.
 241  *
 242  * Return pointer to structure or NULL.
 243  */
 244 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan)
 245 {
 246         struct ltt_ust_channel *luc;
 247
 248         assert(chan);
 249
 250         luc = zmalloc(sizeof(struct ltt_ust_channel));
 251         if (luc == NULL) {
 252                 PERROR("ltt_ust_channel zmalloc");
 253                 goto error;
 254         }
 255
 256         /* Copy UST channel attributes */
 257         luc->attr.overwrite = chan->attr.overwrite;
 258         luc->attr.subbuf_size = chan->attr.subbuf_size;
 259         luc->attr.num_subbuf = chan->attr.num_subbuf;
 260         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 261         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 262         luc->attr.output = (enum lttng_ust_output) chan->attr.output;
 263
 264         /* Translate to UST output enum */
 265         switch (luc->attr.output) {
 266         default:
 267                 luc->attr.output = LTTNG_UST_MMAP;
 268                 break;
 269         }
 270
 271         /* Copy channel name */
 272         strncpy(luc->name, chan->name, sizeof(luc->name));
 273         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 274
 275         /* Init node */
 276         lttng_ht_node_init_str(&luc->node, luc->name);
 277         /* Alloc hash tables */
 278         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 279         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 280
 281         /* On-disk circular buffer parameters */
 282         luc->tracefile_size = chan->attr.tracefile_size;
 283         luc->tracefile_count = chan->attr.tracefile_count;
 284
 285         DBG2("Trace UST channel %s created", luc->name);
 286
 287 error:
 288         return luc;
 289 }
 290
 291 /*
 292  * Allocate and initialize a ust event. Set name and event type.
 293  *
 294  * Return pointer to structure or NULL.
 295  */
 296 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
 297                 struct lttng_filter_bytecode *filter)
 298 {
 299         struct ltt_ust_event *lue;
 300
 301         assert(ev);
 302
 303         lue = zmalloc(sizeof(struct ltt_ust_event));
 304         if (lue == NULL) {
 305                 PERROR("ust event zmalloc");
 306                 goto error;
 307         }
 308
 309         switch (ev->type) {
 310         case LTTNG_EVENT_PROBE:
 311                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 312                 break;
 313         case LTTNG_EVENT_FUNCTION:
 314                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 315                 break;
 316         case LTTNG_EVENT_FUNCTION_ENTRY:
 317                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 318                 break;
 319         case LTTNG_EVENT_TRACEPOINT:
 320                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 321                 break;
 322         default:
 323                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 324                 goto error_free_event;
 325         }
 326
 327         /* Copy event name */
 328         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 329         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 330
 331         switch (ev->loglevel_type) {
 332         case LTTNG_EVENT_LOGLEVEL_ALL:
 333                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
 334                 lue->attr.loglevel = -1;        /* Force to -1 */
 335                 break;
 336         case LTTNG_EVENT_LOGLEVEL_RANGE:
 337                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
 338                 lue->attr.loglevel = ev->loglevel;
 339                 break;
 340         case LTTNG_EVENT_LOGLEVEL_SINGLE:
 341                 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
 342                 lue->attr.loglevel = ev->loglevel;
 343                 break;
 344         default:
 345                 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
 346                 goto error_free_event;
 347         }
 348
 349         /* Same layout. */
 350         lue->filter = (struct lttng_ust_filter_bytecode *) filter;
 351
 352         /* Init node */
 353         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 354
 355         DBG2("Trace UST event %s, loglevel (%d,%d) created",
 356                 lue->attr.name, lue->attr.loglevel_type,
 357                 lue->attr.loglevel);
 358
 359         return lue;
 360
 361 error_free_event:
 362         free(lue);
 363 error:
 364         return NULL;
 365 }
 366
 367 /*
 368  * Allocate and initialize a ust metadata.
 369  *
 370  * Return pointer to structure or NULL.
 371  */
 372 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 373 {
 374         int ret;
 375         struct ltt_ust_metadata *lum;
 376
 377         assert(path);
 378
 379         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 380         if (lum == NULL) {
 381                 PERROR("ust metadata zmalloc");
 382                 goto error;
 383         }
 384
 385         /* Set default attributes */
 386         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 387         lum->attr.subbuf_size = default_get_metadata_subbuf_size();
 388         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 389         lum->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 390         lum->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
 391         lum->attr.output = LTTNG_UST_MMAP;
 392
 393         lum->handle = -1;
 394         /* Set metadata trace path */
 395         ret = snprintf(lum->pathname, PATH_MAX, "%s/" DEFAULT_METADATA_NAME, path);
 396         if (ret < 0) {
 397                 PERROR("asprintf ust metadata");
 398                 goto error_free_metadata;
 399         }
 400
 401         return lum;
 402
 403 error_free_metadata:
 404         free(lum);
 405 error:
 406         return NULL;
 407 }
 408
 409 /*
 410  * Allocate and initialize an UST context.
 411  *
 412  * Return pointer to structure or NULL.
 413  */
 414 struct ltt_ust_context *trace_ust_create_context(
 415                 struct lttng_event_context *ctx)
 416 {
 417         struct ltt_ust_context *uctx;
 418         enum lttng_ust_context_type utype;
 419
 420         assert(ctx);
 421
 422         switch (ctx->ctx) {
 423         case LTTNG_EVENT_CONTEXT_VTID:
 424                 utype = LTTNG_UST_CONTEXT_VTID;
 425                 break;
 426         case LTTNG_EVENT_CONTEXT_VPID:
 427                 utype = LTTNG_UST_CONTEXT_VPID;
 428                 break;
 429         case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
 430                 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
 431                 break;
 432         case LTTNG_EVENT_CONTEXT_PROCNAME:
 433                 utype = LTTNG_UST_CONTEXT_PROCNAME;
 434                 break;
 435         default:
 436                 ERR("Invalid UST context");
 437                 return NULL;
 438         }
 439
 440         uctx = zmalloc(sizeof(struct ltt_ust_context));
 441         if (uctx == NULL) {
 442                 PERROR("zmalloc ltt_ust_context");
 443                 goto error;
 444         }
 445
 446         uctx->ctx.ctx = utype;
 447         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 448
 449         return uctx;
 450
 451 error:
 452         return NULL;
 453 }
 454
 455 /*
 456  * RCU safe free context structure.
 457  */
 458 static void destroy_context_rcu(struct rcu_head *head)
 459 {
 460         struct lttng_ht_node_ulong *node =
 461                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 462         struct ltt_ust_context *ctx =
 463                 caa_container_of(node, struct ltt_ust_context, node);
 464
 465         free(ctx);
 466 }
 467
 468 /*
 469  * Cleanup UST context hash table.
 470  */
 471 static void destroy_contexts(struct lttng_ht *ht)
 472 {
 473         int ret;
 474         struct lttng_ht_node_ulong *node;
 475         struct lttng_ht_iter iter;
 476
 477         assert(ht);
 478
 479         rcu_read_lock();
 480         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 481                 ret = lttng_ht_del(ht, &iter);
 482                 if (!ret) {
 483                         call_rcu(&node->head, destroy_context_rcu);
 484                 }
 485         }
 486         rcu_read_unlock();
 487
 488         ht_cleanup_push(ht);
 489 }
 490
 491 /*
 492  * Cleanup ust event structure.
 493  */
 494 void trace_ust_destroy_event(struct ltt_ust_event *event)
 495 {
 496         assert(event);
 497
 498         DBG2("Trace destroy UST event %s", event->attr.name);
 499         free(event->filter);
 500         free(event);
 501 }
 502
 503 /*
 504  * URCU intermediate call to complete destroy event.
 505  */
 506 static void destroy_event_rcu(struct rcu_head *head)
 507 {
 508         struct lttng_ht_node_str *node =
 509                 caa_container_of(head, struct lttng_ht_node_str, head);
 510         struct ltt_ust_event *event =
 511                 caa_container_of(node, struct ltt_ust_event, node);
 512
 513         trace_ust_destroy_event(event);
 514 }
 515
 516 /*
 517  * Cleanup UST events hashtable.
 518  */
 519 static void destroy_events(struct lttng_ht *events)
 520 {
 521         int ret;
 522         struct lttng_ht_node_str *node;
 523         struct lttng_ht_iter iter;
 524
 525         assert(events);
 526
 527         rcu_read_lock();
 528         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 529                 ret = lttng_ht_del(events, &iter);
 530                 assert(!ret);
 531                 call_rcu(&node->head, destroy_event_rcu);
 532         }
 533         rcu_read_unlock();
 534
 535         ht_cleanup_push(events);
 536 }
 537
 538 /*
 539  * Cleanup ust channel structure.
 540  *
 541  * Should _NOT_ be called with RCU read lock held.
 542  */
 543 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 544 {
 545         assert(channel);
 546
 547         DBG2("Trace destroy UST channel %s", channel->name);
 548
 549         /* Destroying all events of the channel */
 550         destroy_events(channel->events);
 551         /* Destroying all context of the channel */
 552         destroy_contexts(channel->ctx);
 553
 554         free(channel);
 555 }
 556
 557 /*
 558  * URCU intermediate call to complete destroy channel.
 559  */
 560 static void destroy_channel_rcu(struct rcu_head *head)
 561 {
 562         struct lttng_ht_node_str *node =
 563                 caa_container_of(head, struct lttng_ht_node_str, head);
 564         struct ltt_ust_channel *channel =
 565                 caa_container_of(node, struct ltt_ust_channel, node);
 566
 567         _trace_ust_destroy_channel(channel);
 568 }
 569
 570 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 571 {
 572         call_rcu(&channel->node.head, destroy_channel_rcu);
 573 }
 574
 575 /*
 576  * Remove an UST channel from a channel HT.
 577  */
 578 void trace_ust_delete_channel(struct lttng_ht *ht,
 579                 struct ltt_ust_channel *channel)
 580 {
 581         int ret;
 582         struct lttng_ht_iter iter;
 583
 584         assert(ht);
 585         assert(channel);
 586
 587         iter.iter.node = &channel->node.node;
 588         ret = lttng_ht_del(ht, &iter);
 589         assert(!ret);
 590 }
 591
 592 /*
 593  * Cleanup ust metadata structure.
 594  */
 595 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 596 {
 597         assert(metadata);
 598
 599         if (!metadata->handle) {
 600                 return;
 601         }
 602         DBG2("Trace UST destroy metadata %d", metadata->handle);
 603         free(metadata);
 604 }
 605
 606 /*
 607  * Iterate over a hash table containing channels and cleanup safely.
 608  */
 609 static void destroy_channels(struct lttng_ht *channels)
 610 {
 611         int ret;
 612         struct lttng_ht_node_str *node;
 613         struct lttng_ht_iter iter;
 614
 615         assert(channels);
 616
 617         rcu_read_lock();
 618
 619         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 620                 ret = lttng_ht_del(channels, &iter);
 621                 assert(!ret);
 622                 call_rcu(&node->head, destroy_channel_rcu);
 623         }
 624         rcu_read_unlock();
 625
 626         ht_cleanup_push(channels);
 627 }
 628
 629 /*
 630  * Cleanup UST global domain.
 631  */
 632 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 633 {
 634         assert(dom);
 635
 636         destroy_channels(dom->channels);
 637 }
 638
 639 /*
 640  * Cleanup ust session structure
 641  *
 642  * Should *NOT* be called with RCU read-side lock held.
 643  */
 644 void trace_ust_destroy_session(struct ltt_ust_session *session)
 645 {
 646         struct buffer_reg_uid *reg, *sreg;
 647
 648         assert(session);
 649
 650         DBG2("Trace UST destroy session %" PRIu64, session->id);
 651
 652         /* Cleaning up UST domain */
 653         destroy_domain_global(&session->domain_global);
 654
 655         /* Cleanup UID buffer registry object(s). */
 656         cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
 657                         lnode) {
 658                 cds_list_del(&reg->lnode);
 659                 buffer_reg_uid_remove(reg);
 660                 buffer_reg_uid_destroy(reg, session->consumer);
 661         }
 662
 663         consumer_destroy_output(session->consumer);
 664         consumer_destroy_output(session->tmp_consumer);
 665
 666         free(session);
 667 }