src/bin/lttng-sessiond/trace-kernel.c

   1 /*
   2  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13
  14 #include <lttng/event.h>
  15 #include <lttng/lttng-error.h>
  16 #include <lttng/kernel-probe.h>
  17 #include <lttng/userspace-probe.h>
  18 #include <lttng/userspace-probe-internal.h>
  19 #include <lttng/event-rule/event-rule.h>
  20 #include <lttng/event-rule/event-rule-internal.h>
  21 #include <lttng/event-rule/kprobe.h>
  22 #include <lttng/event-rule/kprobe-internal.h>
  23 #include <lttng/event-rule/syscall.h>
  24 #include <lttng/event-rule/syscall-internal.h>
  25 #include <lttng/event-rule/tracepoint.h>
  26 #include <lttng/event-rule/tracepoint-internal.h>
  27 #include <lttng/event-rule/uprobe-internal.h>
  28 #include <common/common.h>
  29 #include <common/defaults.h>
  30 #include <common/trace-chunk.h>
  31 #include <common/macros.h>
  32
  33 #include "consumer.h"
  34 #include "trace-kernel.h"
  35 #include "lttng-sessiond.h"
  36 #include "notification-thread-commands.h"
  37
  38 /*
  39  * Find the channel name for the given kernel session.
  40  */
  41 struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
  42                 const char *name, struct ltt_kernel_session *session)
  43 {
  44         struct ltt_kernel_channel *chan;
  45
  46         assert(session);
  47         assert(name);
  48
  49         /*
  50          * If we receive an empty string for channel name, it means the
  51          * default channel name is requested.
  52          */
  53         if (name[0] == '\0')
  54                 name = DEFAULT_CHANNEL_NAME;
  55
  56         DBG("Trying to find channel %s", name);
  57
  58         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  59                 if (strcmp(name, chan->channel->name) == 0) {
  60                         DBG("Found channel by name %s", name);
  61                         return chan;
  62                 }
  63         }
  64
  65         return NULL;
  66 }
  67
  68 /*
  69  * Find the event for the given channel.
  70  */
  71 struct ltt_kernel_event *trace_kernel_find_event(
  72                 char *name, struct ltt_kernel_channel *channel,
  73                 enum lttng_event_type type,
  74                 struct lttng_bytecode *filter)
  75 {
  76         struct ltt_kernel_event *ev;
  77         int found = 0;
  78
  79         assert(name);
  80         assert(channel);
  81
  82         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  83                 if (type != LTTNG_EVENT_ALL && ev->type != type) {
  84                         continue;
  85                 }
  86                 if (strcmp(name, ev->event->name)) {
  87                         continue;
  88                 }
  89                 if ((ev->filter && !filter) || (!ev->filter && filter)) {
  90                         continue;
  91                 }
  92                 if (ev->filter && filter) {
  93                         if (ev->filter->len != filter->len ||
  94                                         memcmp(ev->filter->data, filter->data,
  95                                                 filter->len) != 0) {
  96                                 continue;
  97                         }
  98                 }
  99                 found = 1;
 100                 break;
 101         }
 102         if (found) {
 103                 DBG("Found event %s for channel %s", name,
 104                         channel->channel->name);
 105                 return ev;
 106         } else {
 107                 return NULL;
 108         }
 109 }
 110
 111 /*
 112  * Find the event name for the given channel.
 113  */
 114 struct ltt_kernel_event *trace_kernel_get_event_by_name(
 115                 char *name, struct ltt_kernel_channel *channel,
 116                 enum lttng_event_type type)
 117 {
 118         struct ltt_kernel_event *ev;
 119         int found = 0;
 120
 121         assert(name);
 122         assert(channel);
 123
 124         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
 125                 if (type != LTTNG_EVENT_ALL && ev->type != type) {
 126                         continue;
 127                 }
 128                 if (strcmp(name, ev->event->name)) {
 129                         continue;
 130                 }
 131                 found = 1;
 132                 break;
 133         }
 134         if (found) {
 135                 DBG("Found event %s for channel %s", name,
 136                         channel->channel->name);
 137                 return ev;
 138         } else {
 139                 return NULL;
 140         }
 141 }
 142
 143 /*
 144  * Allocate and initialize a kernel session data structure.
 145  *
 146  * Return pointer to structure or NULL.
 147  */
 148 struct ltt_kernel_session *trace_kernel_create_session(void)
 149 {
 150         struct ltt_kernel_session *lks = NULL;
 151
 152         /* Allocate a new ltt kernel session */
 153         lks = zmalloc(sizeof(struct ltt_kernel_session));
 154         if (lks == NULL) {
 155                 PERROR("create kernel session zmalloc");
 156                 goto alloc_error;
 157         }
 158
 159         /* Init data structure */
 160         lks->fd = -1;
 161         lks->metadata_stream_fd = -1;
 162         lks->channel_count = 0;
 163         lks->stream_count_global = 0;
 164         lks->metadata = NULL;
 165         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 166
 167         lks->tracker_pid = process_attr_tracker_create();
 168         if (!lks->tracker_pid) {
 169                 goto error;
 170         }
 171         lks->tracker_vpid = process_attr_tracker_create();
 172         if (!lks->tracker_vpid) {
 173                 goto error;
 174         }
 175         lks->tracker_uid = process_attr_tracker_create();
 176         if (!lks->tracker_uid) {
 177                 goto error;
 178         }
 179         lks->tracker_vuid = process_attr_tracker_create();
 180         if (!lks->tracker_vuid) {
 181                 goto error;
 182         }
 183         lks->tracker_gid = process_attr_tracker_create();
 184         if (!lks->tracker_gid) {
 185                 goto error;
 186         }
 187         lks->tracker_vgid = process_attr_tracker_create();
 188         if (!lks->tracker_vgid) {
 189                 goto error;
 190         }
 191         lks->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 192         if (lks->consumer == NULL) {
 193                 goto error;
 194         }
 195
 196         return lks;
 197
 198 error:
 199         process_attr_tracker_destroy(lks->tracker_pid);
 200         process_attr_tracker_destroy(lks->tracker_vpid);
 201         process_attr_tracker_destroy(lks->tracker_uid);
 202         process_attr_tracker_destroy(lks->tracker_vuid);
 203         process_attr_tracker_destroy(lks->tracker_gid);
 204         process_attr_tracker_destroy(lks->tracker_vgid);
 205         free(lks);
 206
 207 alloc_error:
 208         return NULL;
 209 }
 210
 211 /*
 212  * Allocate and initialize a kernel channel data structure.
 213  *
 214  * Return pointer to structure or NULL.
 215  */
 216 struct ltt_kernel_channel *trace_kernel_create_channel(
 217                 struct lttng_channel *chan)
 218 {
 219         struct ltt_kernel_channel *lkc;
 220         struct lttng_channel_extended *extended = NULL;
 221
 222         assert(chan);
 223
 224         lkc = zmalloc(sizeof(struct ltt_kernel_channel));
 225         if (lkc == NULL) {
 226                 PERROR("ltt_kernel_channel zmalloc");
 227                 goto error;
 228         }
 229
 230         lkc->channel = zmalloc(sizeof(struct lttng_channel));
 231         if (lkc->channel == NULL) {
 232                 PERROR("lttng_channel zmalloc");
 233                 goto error;
 234         }
 235
 236         extended = zmalloc(sizeof(struct lttng_channel_extended));
 237         if (!extended) {
 238                 PERROR("lttng_channel_channel zmalloc");
 239                 goto error;
 240         }
 241         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 242         memcpy(extended, chan->attr.extended.ptr, sizeof(struct lttng_channel_extended));
 243         lkc->channel->attr.extended.ptr = extended;
 244         extended = NULL;
 245
 246         /*
 247          * If we receive an empty string for channel name, it means the
 248          * default channel name is requested.
 249          */
 250         if (chan->name[0] == '\0') {
 251                 strncpy(lkc->channel->name, DEFAULT_CHANNEL_NAME,
 252                         sizeof(lkc->channel->name));
 253         }
 254         lkc->channel->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 255
 256         lkc->fd = -1;
 257         lkc->stream_count = 0;
 258         lkc->event_count = 0;
 259         lkc->enabled = 1;
 260         lkc->published_to_notification_thread = false;
 261         /* Init linked list */
 262         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 263         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 264         CDS_INIT_LIST_HEAD(&lkc->ctx_list);
 265
 266         return lkc;
 267
 268 error:
 269         if (lkc) {
 270                 free(lkc->channel);
 271         }
 272         free(extended);
 273         free(lkc);
 274         return NULL;
 275 }
 276
 277 /*
 278  * Allocate and init a kernel context object.
 279  *
 280  * Return the allocated object or NULL on error.
 281  */
 282 struct ltt_kernel_context *trace_kernel_create_context(
 283                 struct lttng_kernel_context *ctx)
 284 {
 285         struct ltt_kernel_context *kctx;
 286
 287         kctx = zmalloc(sizeof(*kctx));
 288         if (!kctx) {
 289                 PERROR("zmalloc kernel context");
 290                 goto error;
 291         }
 292
 293         if (ctx) {
 294                 memcpy(&kctx->ctx, ctx, sizeof(kctx->ctx));
 295         }
 296 error:
 297         return kctx;
 298 }
 299
 300 /*
 301  * Allocate and init a kernel context object from an existing kernel context
 302  * object.
 303  *
 304  * Return the allocated object or NULL on error.
 305  */
 306 struct ltt_kernel_context *trace_kernel_copy_context(
 307                 struct ltt_kernel_context *kctx)
 308 {
 309         struct ltt_kernel_context *kctx_copy;
 310
 311         assert(kctx);
 312         kctx_copy = zmalloc(sizeof(*kctx_copy));
 313         if (!kctx_copy) {
 314                 PERROR("zmalloc ltt_kernel_context");
 315                 goto error;
 316         }
 317
 318         memcpy(kctx_copy, kctx, sizeof(*kctx_copy));
 319         memset(&kctx_copy->list, 0, sizeof(kctx_copy->list));
 320
 321 error:
 322         return kctx_copy;
 323 }
 324
 325 /*
 326  * Allocate and initialize a kernel event. Set name and event type.
 327  * We own filter_expression, and filter.
 328  *
 329  * Return pointer to structure or NULL.
 330  */
 331 enum lttng_error_code trace_kernel_create_event(
 332                 struct lttng_event *ev, char *filter_expression,
 333                 struct lttng_bytecode *filter,
 334                 struct ltt_kernel_event **kernel_event)
 335 {
 336         enum lttng_error_code ret;
 337         struct lttng_kernel_event *attr;
 338         struct ltt_kernel_event *local_kernel_event;
 339         struct lttng_userspace_probe_location *userspace_probe_location = NULL;
 340
 341         assert(ev);
 342
 343         local_kernel_event = zmalloc(sizeof(struct ltt_kernel_event));
 344         attr = zmalloc(sizeof(struct lttng_kernel_event));
 345         if (local_kernel_event == NULL || attr == NULL) {
 346                 PERROR("kernel event zmalloc");
 347                 ret = LTTNG_ERR_NOMEM;
 348                 goto error;
 349         }
 350
 351         switch (ev->type) {
 352         case LTTNG_EVENT_PROBE:
 353                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 354                 attr->u.kprobe.addr = ev->attr.probe.addr;
 355                 attr->u.kprobe.offset = ev->attr.probe.offset;
 356                 strncpy(attr->u.kprobe.symbol_name,
 357                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 358                 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 359                 break;
 360         case LTTNG_EVENT_USERSPACE_PROBE:
 361         {
 362                 const struct lttng_userspace_probe_location* location = NULL;
 363                 const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
 364
 365                 location = lttng_event_get_userspace_probe_location(ev);
 366                 if (!location) {
 367                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 368                         goto error;
 369                 }
 370
 371                 /*
 372                  * From this point on, the specific term 'uprobe' is used
 373                  * instead of the generic 'userspace probe' because it's the
 374                  * technology used at the moment for this instrumentation.
 375                  * LTTng currently implements userspace probes using uprobes.
 376                  * In the interactions with the kernel tracer, we use the
 377                  * uprobe term.
 378                  */
 379                 attr->instrumentation = LTTNG_KERNEL_UPROBE;
 380
 381                 /*
 382                  * Only the elf lookup method is supported at the moment.
 383                  */
 384                 lookup = lttng_userspace_probe_location_get_lookup_method(
 385                                 location);
 386                 if (!lookup) {
 387                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 388                         goto error;
 389                 }
 390
 391                 /*
 392                  * From the kernel tracer's perspective, all userspace probe
 393                  * event types are all the same: a file and an offset.
 394                  */
 395                 switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
 396                 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
 397                         /* Get the file descriptor on the target binary. */
 398                         attr->u.uprobe.fd =
 399                                         lttng_userspace_probe_location_function_get_binary_fd(location);
 400
 401                         /*
 402                          * Save a reference to the probe location used during
 403                          * the listing of events.
 404                          */
 405                         userspace_probe_location =
 406                                         lttng_userspace_probe_location_copy(location);
 407                         break;
 408                 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
 409                         /* Get the file descriptor on the target binary. */
 410                         attr->u.uprobe.fd =
 411                                         lttng_userspace_probe_location_tracepoint_get_binary_fd(location);
 412
 413                         /*
 414                          * Save a reference to the probe location used during the listing of
 415                          * events.
 416                          */
 417                         userspace_probe_location =
 418                                         lttng_userspace_probe_location_copy(location);
 419                         break;
 420                 default:
 421                         DBG("Unsupported lookup method type");
 422                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 423                         goto error;
 424                 }
 425                 break;
 426         }
 427         case LTTNG_EVENT_FUNCTION:
 428                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 429                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 430                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 431                 strncpy(attr->u.kretprobe.symbol_name,
 432                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 433                 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 434                 break;
 435         case LTTNG_EVENT_FUNCTION_ENTRY:
 436                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 437                 strncpy(attr->u.ftrace.symbol_name,
 438                                 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 439                 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 440                 break;
 441         case LTTNG_EVENT_TRACEPOINT:
 442                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 443                 break;
 444         case LTTNG_EVENT_SYSCALL:
 445                 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
 446                 break;
 447         case LTTNG_EVENT_ALL:
 448                 attr->instrumentation = LTTNG_KERNEL_ALL;
 449                 break;
 450         default:
 451                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 452                 ret = LTTNG_ERR_INVALID;
 453                 goto error;
 454         }
 455
 456         /* Copy event name */
 457         strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
 458         attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 459
 460         /* Setting up a kernel event */
 461         local_kernel_event->fd = -1;
 462         local_kernel_event->event = attr;
 463         local_kernel_event->enabled = 1;
 464         local_kernel_event->filter_expression = filter_expression;
 465         local_kernel_event->filter = filter;
 466         local_kernel_event->userspace_probe_location = userspace_probe_location;
 467
 468         *kernel_event = local_kernel_event;
 469
 470         return LTTNG_OK;
 471
 472 error:
 473         free(filter_expression);
 474         free(filter);
 475         free(local_kernel_event);
 476         free(attr);
 477         return ret;
 478 }
 479
 480 /*
 481  * Allocate and initialize a kernel token event rule.
 482  *
 483  * Return pointer to structure or NULL.
 484  */
 485 enum lttng_error_code trace_kernel_create_token_event_rule(
 486                 struct lttng_trigger *trigger,
 487                 uint64_t token,
 488                 uint64_t trigger_error_counter_index,
 489                 struct ltt_kernel_token_event_rule **kernel_token_event_rule)
 490 {
 491         enum lttng_error_code ret = LTTNG_OK;
 492         struct ltt_kernel_token_event_rule *local_kernel_token_event_rule;
 493         const struct lttng_condition *condition = NULL;
 494         const struct lttng_event_rule *event_rule = NULL;
 495
 496         assert(kernel_token_event_rule);
 497
 498         condition = lttng_trigger_get_condition(trigger);
 499         assert(condition);
 500         assert(lttng_condition_get_type(condition) == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT);
 501
 502         assert(lttng_condition_event_rule_get_rule(condition, &event_rule) == LTTNG_CONDITION_STATUS_OK);
 503         assert(event_rule);
 504         assert(lttng_event_rule_get_type(event_rule) != LTTNG_EVENT_RULE_TYPE_UNKNOWN);
 505
 506         local_kernel_token_event_rule = zmalloc(sizeof(struct ltt_kernel_token_event_rule));
 507         if (local_kernel_token_event_rule == NULL) {
 508                 PERROR("Failed to allocate ltt_kernel_token_event_rule structure");
 509                 ret = LTTNG_ERR_NOMEM;
 510                 goto error;
 511         }
 512
 513         local_kernel_token_event_rule->fd = -1;
 514         local_kernel_token_event_rule->enabled = 1;
 515         local_kernel_token_event_rule->token = token;
 516         local_kernel_token_event_rule->error_counter_index = trigger_error_counter_index;
 517
 518         /* Get the reference of the event rule */
 519         lttng_trigger_get(trigger);
 520
 521         local_kernel_token_event_rule->trigger = trigger;
 522         /* The event rule still own the filter and bytecode */
 523         local_kernel_token_event_rule->filter = lttng_event_rule_get_filter_bytecode(event_rule);
 524
 525         DBG3("[trace] Kernel token event rule %" PRIu64 " allocated", local_kernel_token_event_rule->token);
 526 error:
 527         *kernel_token_event_rule = local_kernel_token_event_rule;
 528         return ret;
 529 }
 530
 531 /*
 532  * Initialize a kernel trigger from an event rule.
 533  */
 534 enum lttng_error_code trace_kernel_init_trigger_from_event_rule(const struct lttng_event_rule *rule,
 535                 struct lttng_kernel_trigger *kernel_trigger)
 536 {
 537         enum lttng_error_code ret;
 538         enum lttng_event_rule_status status;
 539         const char *name = NULL;
 540
 541         /* TODO: do this for now but have disucssion on if this could be the
 542          * responsability of the event_rule itself ala
 543          * "lttng_even_rule_generate_kernel_trigger"
 544          */
 545         switch (lttng_event_rule_get_type(rule)) {
 546         case LTTNG_EVENT_RULE_TYPE_KPROBE:
 547         {
 548                 uint64_t address = 0, offset = 0;
 549                 const char *symbol_name = NULL;
 550                 const struct lttng_kernel_probe_location *location = NULL;
 551                 enum lttng_kernel_probe_location_status k_status;
 552
 553                 status = lttng_event_rule_kprobe_get_location(rule, &location);
 554                 if (status != LTTNG_EVENT_RULE_STATUS_OK) {
 555                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 556                         goto error;
 557                 }
 558
 559                 switch (lttng_kernel_probe_location_get_type(location)) {
 560                 case LTTNG_KERNEL_PROBE_LOCATION_TYPE_ADDRESS:
 561                 {
 562                         k_status = lttng_kernel_probe_location_address_get_address(
 563                                         location, &address);
 564                         if (k_status != LTTNG_KERNEL_PROBE_LOCATION_STATUS_OK) {
 565                                 ERR("Getting kernel probe address failed.");
 566                         }
 567
 568                         break;
 569                 }
 570                 case LTTNG_KERNEL_PROBE_LOCATION_TYPE_SYMBOL_OFFSET:
 571                 {
 572                         k_status = lttng_kernel_probe_location_symbol_get_offset(
 573                                         location, &offset);
 574                         if (k_status != LTTNG_KERNEL_PROBE_LOCATION_STATUS_OK) {
 575                                 ERR("Getting kernel probe symbol offset failed.");
 576                         }
 577
 578                         symbol_name = lttng_kernel_probe_location_symbol_get_name(
 579                                         location);
 580                         break;
 581                 }
 582                 default:
 583                         ERR("Unknown kernel probe location type (%d)",
 584                                         lttng_kernel_probe_location_get_type(
 585                                                         location));
 586                         ret = LTTNG_ERR_INVALID;
 587                         goto error;
 588                 }
 589
 590                 kernel_trigger->instrumentation = LTTNG_KERNEL_KPROBE;
 591                 kernel_trigger->u.kprobe.addr = address;
 592                 kernel_trigger->u.kprobe.offset = offset;
 593                 if (symbol_name) {
 594                         strncpy(kernel_trigger->u.kprobe.symbol_name,
 595                                         symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 596                 }
 597                 kernel_trigger->u.kprobe
 598                                 .symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] =
 599                                 '\0';
 600                 (void) lttng_event_rule_kprobe_get_name(rule, &name);
 601                 ret = LTTNG_OK;
 602                 break;
 603         }
 604         case LTTNG_EVENT_RULE_TYPE_UPROBE:
 605         {
 606                 const struct lttng_userspace_probe_location* location = NULL;
 607                 const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
 608
 609                 status = lttng_event_rule_uprobe_get_location(rule, &location);
 610                 if (status != LTTNG_EVENT_RULE_STATUS_OK) {
 611                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 612                         goto error;
 613                 }
 614
 615                 kernel_trigger->instrumentation = LTTNG_KERNEL_UPROBE;
 616
 617                 /*
 618                  * Only the elf lookup method is supported at the moment.
 619                  */
 620                 lookup = lttng_userspace_probe_location_get_lookup_method(
 621                                 location);
 622                 if (!lookup) {
 623                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 624                         goto error;
 625                 }
 626
 627                 /*
 628                  * From the kernel tracer's perspective, all userspace probe
 629                  * event types are all the same: a file and an offset.
 630                  */
 631                 switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
 632                 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
 633                         /* Get the file descriptor on the target binary. */
 634                         kernel_trigger->u.uprobe.fd =
 635                                         lttng_userspace_probe_location_function_get_binary_fd(location);
 636
 637                         break;
 638                 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
 639                         /* Get the file descriptor on the target binary. */
 640                         kernel_trigger->u.uprobe.fd =
 641                                         lttng_userspace_probe_location_tracepoint_get_binary_fd(location);
 642                         break;
 643                 default:
 644                         DBG("Unsupported lookup method type");
 645                         ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 646                         goto error;
 647                 }
 648
 649                 (void) lttng_event_rule_uprobe_get_name(rule, &name);
 650
 651                 ret = LTTNG_OK;
 652                 break;
 653         }
 654         case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
 655                 assert("Not supported" && 0);
 656                 ret = LTTNG_OK;
 657                 break;
 658         case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
 659                 /* TODO: assert his is a kernel domain event-rule */
 660                 kernel_trigger->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 661                 (void) lttng_event_rule_tracepoint_get_pattern(rule, &name);
 662                 ret = LTTNG_OK;
 663                 break;
 664         case LTTNG_EVENT_RULE_TYPE_SYSCALL:
 665                 kernel_trigger->instrumentation = LTTNG_KERNEL_SYSCALL;
 666                 (void) lttng_event_rule_syscall_get_pattern(rule, &name);
 667                 ret = LTTNG_OK;
 668                 break;
 669         default:
 670                 ERR("Unknown kernel event rule instrumentation type (%d)", lttng_event_rule_get_type(rule));
 671                 ret = LTTNG_ERR_INVALID;
 672                 goto error;
 673         }
 674
 675         /*
 676          * WTF is LTTNG_EVENT_ALL??? and LTTNG_EVENT_FUNTION_ENTRY?????
 677          */
 678
 679         /* Copy event name */
 680         strncpy(kernel_trigger->name, name, LTTNG_KERNEL_SYM_NAME_LEN);
 681         kernel_trigger->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 682
 683 error:
 684         return ret;
 685 }
 686 /*
 687  * Allocate and initialize a kernel metadata.
 688  *
 689  * Return pointer to structure or NULL.
 690  */
 691 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 692 {
 693         int ret;
 694         struct ltt_kernel_metadata *lkm;
 695         struct lttng_channel *chan;
 696
 697         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 698         chan = zmalloc(sizeof(struct lttng_channel));
 699         if (lkm == NULL || chan == NULL) {
 700                 PERROR("kernel metadata zmalloc");
 701                 goto error;
 702         }
 703
 704         ret = lttng_strncpy(
 705                         chan->name, DEFAULT_METADATA_NAME, sizeof(chan->name));
 706         if (ret) {
 707                 ERR("Failed to initialize metadata channel name to `%s`",
 708                                 DEFAULT_METADATA_NAME);
 709                 goto error;
 710         }
 711
 712         /* Set default attributes */
 713         chan->attr.overwrite = DEFAULT_METADATA_OVERWRITE;
 714         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 715         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 716         chan->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
 717         chan->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;;
 718
 719
 720         /*
 721          * The metadata channel of kernel sessions must use the "mmap"
 722          * back-end since the consumer daemon accumulates complete
 723          * metadata units before sending them to the relay daemon in
 724          * live mode. The consumer daemon also needs to extract the contents
 725          * of the metadata cache when computing a rotation position.
 726          *
 727          * In both cases, it is not possible to rely on the splice
 728          * back-end as the consumer daemon may need to accumulate more
 729          * content than can be backed by the ring buffer's underlying
 730          * pages.
 731          */
 732         chan->attr.output = LTTNG_EVENT_MMAP;
 733         chan->attr.tracefile_size = 0;
 734         chan->attr.tracefile_count = 0;
 735         chan->attr.live_timer_interval = 0;
 736
 737         /* Init metadata */
 738         lkm->fd = -1;
 739         lkm->conf = chan;
 740
 741         return lkm;
 742
 743 error:
 744         free(lkm);
 745         free(chan);
 746         return NULL;
 747 }
 748
 749 /*
 750  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 751  * default.
 752  *
 753  * Return pointer to structure or NULL.
 754  */
 755 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 756                 unsigned int count)
 757 {
 758         int ret;
 759         struct ltt_kernel_stream *lks;
 760
 761         assert(name);
 762
 763         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 764         if (lks == NULL) {
 765                 PERROR("kernel stream zmalloc");
 766                 goto error;
 767         }
 768
 769         /* Set name */
 770         ret = snprintf(lks->name, sizeof(lks->name), "%s_%u", name, count);
 771         if (ret < 0) {
 772                 PERROR("snprintf stream name");
 773                 goto error;
 774         }
 775         lks->name[sizeof(lks->name) - 1] = '\0';
 776
 777         /* Init stream */
 778         lks->fd = -1;
 779         lks->state = 0;
 780         lks->cpu = count;
 781
 782         return lks;
 783
 784 error:
 785         return NULL;
 786 }
 787
 788 /*
 789  * Cleanup kernel stream structure.
 790  */
 791 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 792 {
 793         assert(stream);
 794
 795         DBG("[trace] Closing stream fd %d", stream->fd);
 796         /* Close kernel fd */
 797         if (stream->fd >= 0) {
 798                 int ret;
 799
 800                 ret = close(stream->fd);
 801                 if (ret) {
 802                         PERROR("close");
 803                 }
 804         }
 805         /* Remove from stream list */
 806         cds_list_del(&stream->list);
 807
 808         free(stream);
 809 }
 810
 811 /*
 812  * Cleanup kernel event structure.
 813  */
 814 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 815 {
 816         assert(event);
 817
 818         if (event->fd >= 0) {
 819                 int ret;
 820
 821                 DBG("[trace] Closing event fd %d", event->fd);
 822                 /* Close kernel fd */
 823                 ret = close(event->fd);
 824                 if (ret) {
 825                         PERROR("close");
 826                 }
 827         } else {
 828                 DBG("[trace] Tearing down event (no associated fd)");
 829         }
 830
 831         /* Remove from event list */
 832         cds_list_del(&event->list);
 833
 834         free(event->filter_expression);
 835         free(event->filter);
 836
 837         free(event->event);
 838         free(event);
 839 }
 840
 841 /*
 842  * Cleanup kernel event structure.
 843  */
 844 void trace_kernel_destroy_token_event_rule(struct ltt_kernel_token_event_rule *event)
 845 {
 846         /* TODO: review in depth to ensure adequate disposing */
 847         assert(event);
 848
 849         if (event->fd >= 0) {
 850                 int ret;
 851
 852                 DBG("[trace] Closing ,token event rule fd %d", event->fd);
 853                 /* Close kernel fd */
 854                 ret = close(event->fd);
 855                 if (ret) {
 856                         PERROR("close");
 857                 }
 858         } else {
 859                 DBG("[trace] Tearing down token event rule (no associated fd)");
 860         }
 861
 862         lttng_trigger_put(event->trigger);
 863         free(event);
 864 }
 865 /*
 866  * Cleanup kernel context structure.
 867  */
 868 void trace_kernel_destroy_context(struct ltt_kernel_context *ctx)
 869 {
 870         assert(ctx);
 871
 872         if (ctx->in_list) {
 873                 cds_list_del(&ctx->list);
 874         }
 875         free(ctx);
 876 }
 877
 878 /*
 879  * Cleanup kernel channel structure.
 880  */
 881 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 882 {
 883         struct ltt_kernel_stream *stream, *stmp;
 884         struct ltt_kernel_event *event, *etmp;
 885         struct ltt_kernel_context *ctx, *ctmp;
 886         int ret;
 887         enum lttng_error_code status;
 888
 889         assert(channel);
 890
 891         DBG("[trace] Closing channel fd %d", channel->fd);
 892         /* Close kernel fd */
 893         if (channel->fd >= 0) {
 894                 ret = close(channel->fd);
 895                 if (ret) {
 896                         PERROR("close");
 897                 }
 898         }
 899
 900         /* For each stream in the channel list */
 901         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 902                 trace_kernel_destroy_stream(stream);
 903         }
 904
 905         /* For each event in the channel list */
 906         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 907                 trace_kernel_destroy_event(event);
 908         }
 909
 910         /* For each context in the channel list */
 911         cds_list_for_each_entry_safe(ctx, ctmp, &channel->ctx_list, list) {
 912                 trace_kernel_destroy_context(ctx);
 913         }
 914
 915         /* Remove from channel list */
 916         cds_list_del(&channel->list);
 917
 918         if (notification_thread_handle
 919                         && channel->published_to_notification_thread) {
 920                 status = notification_thread_command_remove_channel(
 921                                 notification_thread_handle,
 922                                 channel->key, LTTNG_DOMAIN_KERNEL);
 923                 assert(status == LTTNG_OK);
 924         }
 925         free(channel->channel->attr.extended.ptr);
 926         free(channel->channel);
 927         free(channel);
 928 }
 929
 930 /*
 931  * Cleanup kernel metadata structure.
 932  */
 933 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 934 {
 935         assert(metadata);
 936
 937         DBG("[trace] Closing metadata fd %d", metadata->fd);
 938         /* Close kernel fd */
 939         if (metadata->fd >= 0) {
 940                 int ret;
 941
 942                 ret = close(metadata->fd);
 943                 if (ret) {
 944                         PERROR("close");
 945                 }
 946         }
 947
 948         free(metadata->conf);
 949         free(metadata);
 950 }
 951
 952 /*
 953  * Cleanup kernel session structure
 954  *
 955  * Should *NOT* be called with RCU read-side lock held.
 956  */
 957 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 958 {
 959         struct ltt_kernel_channel *channel, *ctmp;
 960         int ret;
 961
 962         assert(session);
 963
 964         DBG("[trace] Closing session fd %d", session->fd);
 965         /* Close kernel fds */
 966         if (session->fd >= 0) {
 967                 ret = close(session->fd);
 968                 if (ret) {
 969                         PERROR("close");
 970                 }
 971         }
 972
 973         if (session->metadata_stream_fd >= 0) {
 974                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 975                 ret = close(session->metadata_stream_fd);
 976                 if (ret) {
 977                         PERROR("close");
 978                 }
 979         }
 980
 981         if (session->metadata != NULL) {
 982                 trace_kernel_destroy_metadata(session->metadata);
 983         }
 984
 985         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 986                 trace_kernel_destroy_channel(channel);
 987         }
 988 }
 989
 990 /* Free elements needed by destroy notifiers. */
 991 void trace_kernel_free_session(struct ltt_kernel_session *session)
 992 {
 993         /* Wipe consumer output object */
 994         consumer_output_put(session->consumer);
 995
 996         process_attr_tracker_destroy(session->tracker_pid);
 997         process_attr_tracker_destroy(session->tracker_vpid);
 998         process_attr_tracker_destroy(session->tracker_uid);
 999         process_attr_tracker_destroy(session->tracker_vuid);
1000         process_attr_tracker_destroy(session->tracker_gid);
1001         process_attr_tracker_destroy(session->tracker_vgid);
1002
1003         free(session);
1004 }