src/bin/lttng-sessiond/event.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 #define _LGPL_SOURCE
  20 #include <errno.h>
  21 #include <urcu/list.h>
  22 #include <string.h>
  23
  24 #include <lttng/lttng.h>
  25 #include <common/error.h>
  26 #include <common/sessiond-comm/sessiond-comm.h>
  27
  28 #include "channel.h"
  29 #include "event.h"
  30 #include "kernel.h"
  31 #include "lttng-sessiond.h"
  32 #include "ust-ctl.h"
  33 #include "ust-app.h"
  34 #include "trace-kernel.h"
  35 #include "trace-ust.h"
  36 #include "agent.h"
  37
  38 /*
  39  * Add unique UST event based on the event name, filter bytecode and loglevel.
  40  */
  41 static void add_unique_ust_event(struct lttng_ht *ht,
  42                 struct ltt_ust_event *event)
  43 {
  44         struct cds_lfht_node *node_ptr;
  45         struct ltt_ust_ht_key key;
  46
  47         assert(ht);
  48         assert(ht->ht);
  49         assert(event);
  50
  51         key.name = event->attr.name;
  52         key.filter = (struct lttng_filter_bytecode *) event->filter;
  53         key.loglevel_type = event->attr.loglevel_type;
  54         key.loglevel_value = event->attr.loglevel;
  55         key.exclusion = event->exclusion;
  56
  57         node_ptr = cds_lfht_add_unique(ht->ht,
  58                         ht->hash_fct(event->node.key, lttng_ht_seed),
  59                         trace_ust_ht_match_event, &key, &event->node.node);
  60         assert(node_ptr == &event->node.node);
  61 }
  62
  63 /*
  64  * Disable kernel tracepoint event for a channel from the kernel session.
  65  */
  66 int event_kernel_disable_event(struct ltt_kernel_channel *kchan,
  67                 char *event_name)
  68 {
  69         int ret;
  70         struct ltt_kernel_event *kevent;
  71
  72         assert(kchan);
  73
  74         kevent = trace_kernel_get_event_by_name(event_name, kchan,
  75                         LTTNG_EVENT_ALL);
  76         if (kevent == NULL) {
  77                 ret = LTTNG_ERR_NO_EVENT;
  78                 goto error;
  79         }
  80
  81         ret = kernel_disable_event(kevent);
  82         if (ret < 0) {
  83                 ret = LTTNG_ERR_KERN_DISABLE_FAIL;
  84                 goto error;
  85         }
  86
  87         DBG("Kernel event %s disable for channel %s.",
  88                         kevent->event->name, kchan->channel->name);
  89
  90         ret = LTTNG_OK;
  91
  92 error:
  93         return ret;
  94 }
  95
  96 /*
  97  * Disable kernel tracepoint events for a channel from the kernel session.
  98  */
  99 int event_kernel_disable_event_type(struct ltt_kernel_channel *kchan,
 100                 enum lttng_event_type type)
 101 {
 102         int ret;
 103         struct ltt_kernel_event *kevent;
 104
 105         assert(kchan);
 106
 107         /* For each event in the kernel session */
 108         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
 109                 if (type != LTTNG_EVENT_ALL && kevent->type != type)
 110                         continue;
 111                 ret = kernel_disable_event(kevent);
 112                 if (ret < 0) {
 113                         /* We continue disabling the rest */
 114                         continue;
 115                 }
 116         }
 117         ret = LTTNG_OK;
 118         return ret;
 119 }
 120
 121 /*
 122  * Disable all kernel event for a channel from the kernel session.
 123  */
 124 int event_kernel_disable_event_all(struct ltt_kernel_channel *kchan)
 125 {
 126         return event_kernel_disable_event_type(kchan, LTTNG_EVENT_ALL);
 127 }
 128
 129 /*
 130  * Enable kernel tracepoint event for a channel from the kernel session.
 131  * We own filter_expression and filter.
 132  */
 133 int event_kernel_enable_event(struct ltt_kernel_channel *kchan,
 134                 struct lttng_event *event, char *filter_expression,
 135                 struct lttng_filter_bytecode *filter)
 136 {
 137         int ret;
 138         struct ltt_kernel_event *kevent;
 139
 140         assert(kchan);
 141         assert(event);
 142
 143         kevent = trace_kernel_find_event(event->name, kchan,
 144                         event->type, filter);
 145         if (kevent == NULL) {
 146                 ret = kernel_create_event(event, kchan,
 147                         filter_expression, filter);
 148                 /* We have passed ownership */
 149                 filter_expression = NULL;
 150                 filter = NULL;
 151                 if (ret < 0) {
 152                         switch (-ret) {
 153                         case EEXIST:
 154                                 ret = LTTNG_ERR_KERN_EVENT_EXIST;
 155                                 break;
 156                         case ENOSYS:
 157                                 ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
 158                                 break;
 159                         default:
 160                                 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
 161                                 break;
 162                         }
 163                         goto end;
 164                 }
 165         } else if (kevent->enabled == 0) {
 166                 ret = kernel_enable_event(kevent);
 167                 if (ret < 0) {
 168                         ret = LTTNG_ERR_KERN_ENABLE_FAIL;
 169                         goto end;
 170                 }
 171         } else {
 172                 /* At this point, the event is considered enabled */
 173                 ret = LTTNG_ERR_KERN_EVENT_EXIST;
 174                 goto end;
 175         }
 176
 177         ret = LTTNG_OK;
 178 end:
 179         free(filter_expression);
 180         free(filter);
 181         return ret;
 182 }
 183
 184 /*
 185  * ============================
 186  * UST : The Ultimate Frontier!
 187  * ============================
 188  */
 189
 190 /*
 191  * Enable UST tracepoint event for a channel from a UST session.
 192  * We own filter_expression, filter, and exclusion.
 193  */
 194 int event_ust_enable_tracepoint(struct ltt_ust_session *usess,
 195                 struct ltt_ust_channel *uchan, struct lttng_event *event,
 196                 char *filter_expression,
 197                 struct lttng_filter_bytecode *filter,
 198                 struct lttng_event_exclusion *exclusion,
 199                 bool internal_event)
 200 {
 201         int ret = LTTNG_OK, to_create = 0;
 202         struct ltt_ust_event *uevent;
 203
 204         assert(usess);
 205         assert(uchan);
 206         assert(event);
 207
 208         rcu_read_lock();
 209
 210         uevent = trace_ust_find_event(uchan->events, event->name, filter,
 211                         event->loglevel_type, event->loglevel, exclusion);
 212         if (!uevent) {
 213                 uevent = trace_ust_create_event(event, filter_expression,
 214                                 filter, exclusion, internal_event);
 215                 /* We have passed ownership */
 216                 filter_expression = NULL;
 217                 filter = NULL;
 218                 exclusion = NULL;
 219                 if (uevent == NULL) {
 220                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
 221                         goto error;
 222                 }
 223
 224                 /* Valid to set it after the goto error since uevent is still NULL */
 225                 to_create = 1;
 226         }
 227
 228         if (uevent->enabled) {
 229                 /* It's already enabled so everything is OK */
 230                 ret = LTTNG_ERR_UST_EVENT_ENABLED;
 231                 goto end;
 232         }
 233
 234         uevent->enabled = 1;
 235
 236         if (to_create) {
 237                 /* Create event on all UST registered apps for session */
 238                 ret = ust_app_create_event_glb(usess, uchan, uevent);
 239         } else {
 240                 /* Enable event on all UST registered apps for session */
 241                 ret = ust_app_enable_event_glb(usess, uchan, uevent);
 242         }
 243
 244         if (ret < 0) {
 245                 if (ret == -LTTNG_UST_ERR_EXIST) {
 246                         ret = LTTNG_ERR_UST_EVENT_EXIST;
 247                         goto end;
 248                 } else {
 249                         ret = LTTNG_ERR_UST_ENABLE_FAIL;
 250                         goto error;
 251                 }
 252         }
 253
 254         if (to_create) {
 255                 /* Add ltt ust event to channel */
 256                 add_unique_ust_event(uchan->events, uevent);
 257         }
 258
 259         DBG("Event UST %s %s in channel %s", uevent->attr.name,
 260                         to_create ? "created" : "enabled", uchan->name);
 261
 262         ret = LTTNG_OK;
 263
 264 end:
 265         rcu_read_unlock();
 266         free(filter_expression);
 267         free(filter);
 268         free(exclusion);
 269         return ret;
 270
 271 error:
 272         /*
 273          * Only destroy event on creation time (not enabling time) because if the
 274          * event is found in the channel (to_create == 0), it means that at some
 275          * point the enable_event worked and it's thus valid to keep it alive.
 276          * Destroying it also implies that we also destroy it's shadow copy to sync
 277          * everyone up.
 278          */
 279         if (to_create) {
 280                 /* In this code path, the uevent was not added to the hash table */
 281                 trace_ust_destroy_event(uevent);
 282         }
 283         rcu_read_unlock();
 284         free(filter_expression);
 285         free(filter);
 286         free(exclusion);
 287         return ret;
 288 }
 289
 290 /*
 291  * Disable UST tracepoint of a channel from a UST session.
 292  */
 293 int event_ust_disable_tracepoint(struct ltt_ust_session *usess,
 294                 struct ltt_ust_channel *uchan, char *event_name)
 295 {
 296         int ret;
 297         struct ltt_ust_event *uevent;
 298         struct lttng_ht_node_str *node;
 299         struct lttng_ht_iter iter;
 300         struct lttng_ht *ht;
 301
 302         assert(usess);
 303         assert(uchan);
 304         assert(event_name);
 305
 306         ht = uchan->events;
 307
 308         rcu_read_lock();
 309
 310         /*
 311          * We use a custom lookup since we need the iterator for the next_duplicate
 312          * call in the do while loop below.
 313          */
 314         cds_lfht_lookup(ht->ht, ht->hash_fct((void *) event_name, lttng_ht_seed),
 315                         trace_ust_ht_match_event_by_name, event_name, &iter.iter);
 316         node = lttng_ht_iter_get_node_str(&iter);
 317         if (node == NULL) {
 318                 DBG2("Trace UST event NOT found by name %s", event_name);
 319                 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 320                 goto error;
 321         }
 322
 323         do {
 324                 uevent = caa_container_of(node, struct ltt_ust_event, node);
 325                 assert(uevent);
 326
 327                 if (uevent->enabled == 0) {
 328                         /* It's already disabled so everything is OK */
 329                         goto next;
 330                 }
 331
 332                 ret = ust_app_disable_event_glb(usess, uchan, uevent);
 333                 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
 334                         ret = LTTNG_ERR_UST_DISABLE_FAIL;
 335                         goto error;
 336                 }
 337                 uevent->enabled = 0;
 338
 339                 DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
 340                                 uchan->name);
 341
 342 next:
 343                 /* Get next duplicate event by name. */
 344                 cds_lfht_next_duplicate(ht->ht, trace_ust_ht_match_event_by_name,
 345                                 event_name, &iter.iter);
 346                 node = lttng_ht_iter_get_node_str(&iter);
 347         } while (node);
 348
 349         ret = LTTNG_OK;
 350
 351 error:
 352         rcu_read_unlock();
 353         return ret;
 354 }
 355
 356 /*
 357  * Enable all agent event for a given UST session.
 358  *
 359  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 360  */
 361 int event_agent_enable_all(struct ltt_ust_session *usess,
 362                 struct agent *agt, struct lttng_event *event,
 363                 struct lttng_filter_bytecode *filter ,char *filter_expression)
 364 {
 365         int ret;
 366         struct agent_event *aevent;
 367         struct lttng_ht_iter iter;
 368
 369         assert(usess);
 370
 371         DBG("Event agent enabling ALL events for session %" PRIu64, usess->id);
 372
 373         /* Enable event on agent application through TCP socket. */
 374         ret = event_agent_enable(usess, agt, event, filter, filter_expression);
 375         if (ret != LTTNG_OK) {
 376                 goto error;
 377         }
 378
 379         /* Flag every event that they are now enabled. */
 380         rcu_read_lock();
 381         cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
 382                         node.node) {
 383                 aevent->enabled = 1;
 384         }
 385         rcu_read_unlock();
 386
 387         ret = LTTNG_OK;
 388
 389 error:
 390         return ret;
 391 }
 392
 393 /*
 394  * Enable a single agent event for a given UST session.
 395  *
 396  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 397  */
 398 int event_agent_enable(struct ltt_ust_session *usess,
 399                 struct agent *agt, struct lttng_event *event,
 400                 struct lttng_filter_bytecode *filter,
 401                 char *filter_expression)
 402 {
 403         int ret, created = 0;
 404         struct agent_event *aevent;
 405
 406         assert(usess);
 407         assert(event);
 408         assert(agt);
 409
 410         DBG("Event agent enabling %s for session %" PRIu64 " with loglevel type %d "
 411                         ", loglevel %d and filter \"%s\"", event->name,
 412                         usess->id, event->loglevel_type, event->loglevel,
 413                         filter_expression ? filter_expression : "NULL");
 414
 415         aevent = agent_find_event(event->name, event->loglevel_type,
 416                 event->loglevel, agt);
 417         if (!aevent) {
 418                 aevent = agent_create_event(event->name, event->loglevel_type,
 419                                 event->loglevel, filter,
 420                                 filter_expression);
 421                 if (!aevent) {
 422                         ret = LTTNG_ERR_NOMEM;
 423                         goto error;
 424                 }
 425                 created = 1;
 426         }
 427
 428         /* Already enabled? */
 429         if (aevent->enabled) {
 430                 goto end;
 431         }
 432
 433         ret = agent_enable_event(aevent, agt->domain);
 434         if (ret != LTTNG_OK) {
 435                 goto error;
 436         }
 437
 438         /* If the event was created prior to the enable, add it to the domain. */
 439         if (created) {
 440                 agent_add_event(aevent, agt);
 441         }
 442
 443 end:
 444         return LTTNG_OK;
 445
 446 error:
 447         if (created) {
 448                 agent_destroy_event(aevent);
 449         }
 450         return ret;
 451 }
 452
 453 /*
 454  * Return the default event name associated with the provided UST domain. Return
 455  * NULL on error.
 456  */
 457 const char *event_get_default_agent_ust_name(enum lttng_domain_type domain)
 458 {
 459         const char *default_event_name = NULL;
 460
 461         switch (domain) {
 462         case LTTNG_DOMAIN_LOG4J:
 463                 default_event_name = DEFAULT_LOG4J_EVENT_NAME;
 464                 break;
 465         case LTTNG_DOMAIN_JUL:
 466                 default_event_name = DEFAULT_JUL_EVENT_NAME;
 467                 break;
 468         case LTTNG_DOMAIN_PYTHON:
 469                 default_event_name = DEFAULT_PYTHON_EVENT_NAME;
 470                 break;
 471         default:
 472                 assert(0);
 473         }
 474
 475         return default_event_name;
 476 }
 477
 478 /*
 479  * Disable a given agent event for a given UST session.
 480  *
 481  * Must be called with the RCU read lock held.
 482  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 483  */
 484 static int event_agent_disable_one(struct ltt_ust_session *usess,
 485                 struct agent *agt, struct agent_event *aevent)
 486 {
 487         int ret;
 488         struct ltt_ust_event *uevent = NULL;
 489         struct ltt_ust_channel *uchan = NULL;
 490         const char *ust_event_name, *ust_channel_name;
 491
 492         assert(agt);
 493         assert(usess);
 494         assert(aevent);
 495
 496         DBG("Event agent disabling %s (loglevel type %d, loglevel value %d) for session %" PRIu64,
 497                 aevent->name, aevent->loglevel_type, aevent->loglevel_value,
 498                 usess->id);
 499
 500         /* Already disabled? */
 501         if (!aevent->enabled) {
 502                 goto end;
 503         }
 504
 505         if (agt->domain == LTTNG_DOMAIN_JUL) {
 506                 ust_channel_name = DEFAULT_JUL_CHANNEL_NAME;
 507         } else if (agt->domain == LTTNG_DOMAIN_LOG4J) {
 508                 ust_channel_name = DEFAULT_LOG4J_CHANNEL_NAME;
 509         } else if (agt->domain == LTTNG_DOMAIN_PYTHON) {
 510                 ust_channel_name = DEFAULT_PYTHON_CHANNEL_NAME;
 511         } else {
 512                 ret = LTTNG_ERR_INVALID;
 513                 goto error;
 514         }
 515
 516         /*
 517          * Disable it on the UST side. First get the channel reference then find
 518          * the event and finally disable it.
 519          */
 520         uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 521                         (char *) ust_channel_name);
 522         if (!uchan) {
 523                 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 524                 goto error;
 525         }
 526
 527         ust_event_name = event_get_default_agent_ust_name(agt->domain);
 528         if (!ust_event_name) {
 529                 ret = LTTNG_ERR_FATAL;
 530                 goto error;
 531         }
 532
 533         /*
 534          * Agent UST event has its loglevel type forced to
 535          * LTTNG_UST_LOGLEVEL_ALL. The actual loglevel type/value filtering
 536          * happens thanks to an UST filter. The following -1 is actually
 537          * ignored since the type is LTTNG_UST_LOGLEVEL_ALL.
 538          */
 539         uevent = trace_ust_find_event(uchan->events, (char *) ust_event_name,
 540                         aevent->filter, LTTNG_UST_LOGLEVEL_ALL, -1, NULL);
 541         /* If the agent event exists, it must be available on the UST side. */
 542         assert(uevent);
 543
 544         ret = ust_app_disable_event_glb(usess, uchan, uevent);
 545         if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
 546                 ret = LTTNG_ERR_UST_DISABLE_FAIL;
 547                 goto error;
 548         }
 549
 550         /*
 551          * Flag event that it's disabled so the shadow copy on the ust app side
 552          * will disable it if an application shows up.
 553          */
 554         uevent->enabled = 0;
 555
 556         ret = agent_disable_event(aevent, agt->domain);
 557         if (ret != LTTNG_OK) {
 558                 goto error;
 559         }
 560
 561 end:
 562         return LTTNG_OK;
 563
 564 error:
 565         return ret;
 566 }
 567
 568 /*
 569  * Disable all agent events matching a given name for a given UST session.
 570  *
 571  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 572  */
 573 int event_agent_disable(struct ltt_ust_session *usess, struct agent *agt,
 574                 char *event_name)
 575 {
 576         int ret = LTTNG_OK;
 577         struct agent_event *aevent;
 578         struct lttng_ht_iter iter;
 579         struct lttng_ht_node_str *node;
 580
 581         assert(agt);
 582         assert(usess);
 583         assert(event_name);
 584
 585         DBG("Event agent disabling %s (all loglevels) for session %" PRIu64, event_name, usess->id);
 586
 587         rcu_read_lock();
 588         agent_find_events_by_name(event_name, agt, &iter);
 589         node = lttng_ht_iter_get_node_str(&iter);
 590
 591         if (node == NULL) {
 592                 DBG2("Event agent NOT found by name %s", event_name);
 593                 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 594                 goto end;
 595         }
 596
 597         do {
 598                 aevent = caa_container_of(node, struct agent_event, node);
 599                 ret = event_agent_disable_one(usess, agt, aevent);
 600
 601                 if (ret != LTTNG_OK) {
 602                         goto end;
 603                 }
 604
 605                 /* Get next duplicate agent event by name. */
 606                 agent_event_next_duplicate(event_name, agt, &iter);
 607                 node = lttng_ht_iter_get_node_str(&iter);
 608         } while (node);
 609 end:
 610         rcu_read_unlock();
 611         return ret;
 612 }
 613 /*
 614  * Disable all agent event for a given UST session.
 615  *
 616  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 617  */
 618 int event_agent_disable_all(struct ltt_ust_session *usess,
 619                 struct agent *agt)
 620 {
 621         int ret;
 622         struct agent_event *aevent;
 623         struct lttng_ht_iter iter;
 624
 625         assert(agt);
 626         assert(usess);
 627
 628         /*
 629          * Disable event on agent application. Continue to disable all other events
 630          * if the * event is not found.
 631          */
 632         ret = event_agent_disable(usess, agt, "*");
 633         if (ret != LTTNG_OK && ret != LTTNG_ERR_UST_EVENT_NOT_FOUND) {
 634                 goto error;
 635         }
 636
 637         /* Disable every event. */
 638         rcu_read_lock();
 639         cds_lfht_for_each_entry(agt->events->ht, &iter.iter, aevent,
 640                         node.node) {
 641                 if (!aevent->enabled) {
 642                         continue;
 643                 }
 644
 645                 ret = event_agent_disable(usess, agt, aevent->name);
 646                 if (ret != LTTNG_OK) {
 647                         goto error_unlock;
 648                 }
 649         }
 650         rcu_read_unlock();
 651
 652         ret = LTTNG_OK;
 653
 654 error_unlock:
 655         rcu_read_unlock();
 656 error:
 657         return ret;
 658 }