src/bin/lttng-sessiond/trace-kernel.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 _LGPL_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 "consumer.h"
  28 #include "trace-kernel.h"
  29 #include "lttng-sessiond.h"
  30 #include "notification-thread-commands.h"
  31
  32 /*
  33  * Find the channel name for the given kernel session.
  34  */
  35 struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
  36                 char *name, struct ltt_kernel_session *session)
  37 {
  38         struct ltt_kernel_channel *chan;
  39
  40         assert(session);
  41         assert(name);
  42
  43         /*
  44          * If we receive an empty string for channel name, it means the
  45          * default channel name is requested.
  46          */
  47         if (name[0] == '\0')
  48                 name = DEFAULT_CHANNEL_NAME;
  49
  50         DBG("Trying to find channel %s", name);
  51
  52         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  53                 if (strcmp(name, chan->channel->name) == 0) {
  54                         DBG("Found channel by name %s", name);
  55                         return chan;
  56                 }
  57         }
  58
  59         return NULL;
  60 }
  61
  62 /*
  63  * Find the event for the given channel.
  64  */
  65 struct ltt_kernel_event *trace_kernel_find_event(
  66                 char *name, struct ltt_kernel_channel *channel,
  67                 enum lttng_event_type type,
  68                 struct lttng_filter_bytecode *filter)
  69 {
  70         struct ltt_kernel_event *ev;
  71         int found = 0;
  72
  73         assert(name);
  74         assert(channel);
  75
  76         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  77                 if (type != LTTNG_EVENT_ALL && ev->type != type) {
  78                         continue;
  79                 }
  80                 if (strcmp(name, ev->event->name)) {
  81                         continue;
  82                 }
  83                 if ((ev->filter && !filter) || (!ev->filter && filter)) {
  84                         continue;
  85                 }
  86                 if (ev->filter && filter) {
  87                         if (ev->filter->len != filter->len ||
  88                                         memcmp(ev->filter->data, filter->data,
  89                                                 filter->len) != 0) {
  90                                 continue;
  91                         }
  92                 }
  93                 found = 1;
  94                 break;
  95         }
  96         if (found) {
  97                 DBG("Found event %s for channel %s", name,
  98                         channel->channel->name);
  99                 return ev;
 100         } else {
 101                 return NULL;
 102         }
 103 }
 104
 105 /*
 106  * Find the event name for the given channel.
 107  */
 108 struct ltt_kernel_event *trace_kernel_get_event_by_name(
 109                 char *name, struct ltt_kernel_channel *channel,
 110                 enum lttng_event_type type)
 111 {
 112         struct ltt_kernel_event *ev;
 113         int found = 0;
 114
 115         assert(name);
 116         assert(channel);
 117
 118         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
 119                 if (type != LTTNG_EVENT_ALL && ev->type != type) {
 120                         continue;
 121                 }
 122                 if (strcmp(name, ev->event->name)) {
 123                         continue;
 124                 }
 125                 found = 1;
 126                 break;
 127         }
 128         if (found) {
 129                 DBG("Found event %s for channel %s", name,
 130                         channel->channel->name);
 131                 return ev;
 132         } else {
 133                 return NULL;
 134         }
 135 }
 136
 137 /*
 138  * Allocate and initialize a kernel session data structure.
 139  *
 140  * Return pointer to structure or NULL.
 141  */
 142 struct ltt_kernel_session *trace_kernel_create_session(void)
 143 {
 144         struct ltt_kernel_session *lks = NULL;
 145
 146         /* Allocate a new ltt kernel session */
 147         lks = zmalloc(sizeof(struct ltt_kernel_session));
 148         if (lks == NULL) {
 149                 PERROR("create kernel session zmalloc");
 150                 goto alloc_error;
 151         }
 152
 153         /* Init data structure */
 154         lks->fd = -1;
 155         lks->metadata_stream_fd = -1;
 156         lks->channel_count = 0;
 157         lks->stream_count_global = 0;
 158         lks->metadata = NULL;
 159         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 160
 161         lks->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 162         if (lks->consumer == NULL) {
 163                 goto error;
 164         }
 165
 166         return lks;
 167
 168 error:
 169         free(lks);
 170
 171 alloc_error:
 172         return NULL;
 173 }
 174
 175 /*
 176  * Allocate and initialize a kernel channel data structure.
 177  *
 178  * Return pointer to structure or NULL.
 179  */
 180 struct ltt_kernel_channel *trace_kernel_create_channel(
 181                 struct lttng_channel *chan)
 182 {
 183         struct ltt_kernel_channel *lkc;
 184         struct lttng_channel_extended *extended = NULL;
 185
 186         assert(chan);
 187
 188         lkc = zmalloc(sizeof(struct ltt_kernel_channel));
 189         if (lkc == NULL) {
 190                 PERROR("ltt_kernel_channel zmalloc");
 191                 goto error;
 192         }
 193
 194         lkc->channel = zmalloc(sizeof(struct lttng_channel));
 195         if (lkc->channel == NULL) {
 196                 PERROR("lttng_channel zmalloc");
 197                 goto error;
 198         }
 199
 200         extended = zmalloc(sizeof(struct lttng_channel_extended));
 201         if (!extended) {
 202                 PERROR("lttng_channel_channel zmalloc");
 203                 goto error;
 204         }
 205         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 206         memcpy(extended, chan->attr.extended.ptr, sizeof(struct lttng_channel_extended));
 207         lkc->channel->attr.extended.ptr = extended;
 208         extended = NULL;
 209
 210         /*
 211          * If we receive an empty string for channel name, it means the
 212          * default channel name is requested.
 213          */
 214         if (chan->name[0] == '\0') {
 215                 strncpy(lkc->channel->name, DEFAULT_CHANNEL_NAME,
 216                         sizeof(lkc->channel->name));
 217         }
 218         lkc->channel->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 219
 220         lkc->fd = -1;
 221         lkc->stream_count = 0;
 222         lkc->event_count = 0;
 223         lkc->enabled = 1;
 224         lkc->published_to_notification_thread = false;
 225         /* Init linked list */
 226         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 227         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 228         CDS_INIT_LIST_HEAD(&lkc->ctx_list);
 229
 230         return lkc;
 231
 232 error:
 233         if (lkc) {
 234                 free(lkc->channel);
 235         }
 236         free(extended);
 237         free(lkc);
 238         return NULL;
 239 }
 240
 241 /*
 242  * Allocate and init a kernel context object.
 243  *
 244  * Return the allocated object or NULL on error.
 245  */
 246 struct ltt_kernel_context *trace_kernel_create_context(
 247                 struct lttng_kernel_context *ctx)
 248 {
 249         struct ltt_kernel_context *kctx;
 250
 251         kctx = zmalloc(sizeof(*kctx));
 252         if (!kctx) {
 253                 PERROR("zmalloc kernel context");
 254                 goto error;
 255         }
 256
 257         if (ctx) {
 258                 memcpy(&kctx->ctx, ctx, sizeof(kctx->ctx));
 259         }
 260 error:
 261         return kctx;
 262 }
 263
 264 /*
 265  * Allocate and init a kernel context object from an existing kernel context
 266  * object.
 267  *
 268  * Return the allocated object or NULL on error.
 269  */
 270 struct ltt_kernel_context *trace_kernel_copy_context(
 271                 struct ltt_kernel_context *kctx)
 272 {
 273         struct ltt_kernel_context *kctx_copy;
 274
 275         assert(kctx);
 276         kctx_copy = zmalloc(sizeof(*kctx_copy));
 277         if (!kctx_copy) {
 278                 PERROR("zmalloc ltt_kernel_context");
 279                 goto error;
 280         }
 281
 282         memcpy(kctx_copy, kctx, sizeof(*kctx_copy));
 283         memset(&kctx_copy->list, 0, sizeof(kctx_copy->list));
 284
 285 error:
 286         return kctx_copy;
 287 }
 288
 289 /*
 290  * Allocate and initialize a kernel event. Set name and event type.
 291  * We own filter_expression, and filter.
 292  *
 293  * Return pointer to structure or NULL.
 294  */
 295 enum lttng_error_code trace_kernel_create_event(
 296                 struct lttng_event *ev, char *filter_expression,
 297                 struct lttng_filter_bytecode *filter,
 298                 struct ltt_kernel_event **kernel_event)
 299 {
 300         enum lttng_error_code ret;
 301         struct lttng_kernel_event *attr;
 302         struct ltt_kernel_event *local_kernel_event;
 303
 304         assert(ev);
 305
 306         local_kernel_event = zmalloc(sizeof(struct ltt_kernel_event));
 307         attr = zmalloc(sizeof(struct lttng_kernel_event));
 308         if (local_kernel_event == NULL || attr == NULL) {
 309                 PERROR("kernel event zmalloc");
 310                 ret = LTTNG_ERR_NOMEM;
 311                 goto error;
 312         }
 313
 314         switch (ev->type) {
 315         case LTTNG_EVENT_PROBE:
 316                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 317                 attr->u.kprobe.addr = ev->attr.probe.addr;
 318                 attr->u.kprobe.offset = ev->attr.probe.offset;
 319                 strncpy(attr->u.kprobe.symbol_name,
 320                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 321                 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 322                 break;
 323         case LTTNG_EVENT_FUNCTION:
 324                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 325                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 326                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 327                 strncpy(attr->u.kretprobe.symbol_name,
 328                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 329                 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 330                 break;
 331         case LTTNG_EVENT_FUNCTION_ENTRY:
 332                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 333                 strncpy(attr->u.ftrace.symbol_name,
 334                                 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 335                 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 336                 break;
 337         case LTTNG_EVENT_TRACEPOINT:
 338                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 339                 break;
 340         case LTTNG_EVENT_SYSCALL:
 341                 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
 342                 break;
 343         case LTTNG_EVENT_ALL:
 344                 attr->instrumentation = LTTNG_KERNEL_ALL;
 345                 break;
 346         default:
 347                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 348                 ret = LTTNG_ERR_INVALID;
 349                 goto error;
 350         }
 351
 352         /* Copy event name */
 353         strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
 354         attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 355
 356         /* Setting up a kernel event */
 357         local_kernel_event->fd = -1;
 358         local_kernel_event->event = attr;
 359         local_kernel_event->enabled = 1;
 360         local_kernel_event->filter_expression = filter_expression;
 361         local_kernel_event->filter = filter;
 362
 363         *kernel_event = local_kernel_event;
 364
 365         return LTTNG_OK;
 366
 367 error:
 368         free(filter_expression);
 369         free(filter);
 370         free(local_kernel_event);
 371         free(attr);
 372         return ret;
 373 }
 374
 375 /*
 376  * Allocate and initialize a kernel metadata.
 377  *
 378  * Return pointer to structure or NULL.
 379  */
 380 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 381 {
 382         struct ltt_kernel_metadata *lkm;
 383         struct lttng_channel *chan;
 384
 385         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 386         chan = zmalloc(sizeof(struct lttng_channel));
 387         if (lkm == NULL || chan == NULL) {
 388                 PERROR("kernel metadata zmalloc");
 389                 goto error;
 390         }
 391
 392         /* Set default attributes */
 393         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 394         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 395         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 396         chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
 397         chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
 398         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 399
 400         /* Init metadata */
 401         lkm->fd = -1;
 402         lkm->conf = chan;
 403
 404         return lkm;
 405
 406 error:
 407         free(lkm);
 408         free(chan);
 409         return NULL;
 410 }
 411
 412 /*
 413  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 414  * default.
 415  *
 416  * Return pointer to structure or NULL.
 417  */
 418 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 419                 unsigned int count)
 420 {
 421         int ret;
 422         struct ltt_kernel_stream *lks;
 423
 424         assert(name);
 425
 426         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 427         if (lks == NULL) {
 428                 PERROR("kernel stream zmalloc");
 429                 goto error;
 430         }
 431
 432         /* Set name */
 433         ret = snprintf(lks->name, sizeof(lks->name), "%s_%u", name, count);
 434         if (ret < 0) {
 435                 PERROR("snprintf stream name");
 436                 goto error;
 437         }
 438         lks->name[sizeof(lks->name) - 1] = '\0';
 439
 440         /* Init stream */
 441         lks->fd = -1;
 442         lks->state = 0;
 443         lks->cpu = count;
 444
 445         return lks;
 446
 447 error:
 448         return NULL;
 449 }
 450
 451 /*
 452  * Cleanup kernel stream structure.
 453  */
 454 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 455 {
 456         assert(stream);
 457
 458         DBG("[trace] Closing stream fd %d", stream->fd);
 459         /* Close kernel fd */
 460         if (stream->fd >= 0) {
 461                 int ret;
 462
 463                 ret = close(stream->fd);
 464                 if (ret) {
 465                         PERROR("close");
 466                 }
 467         }
 468         /* Remove from stream list */
 469         cds_list_del(&stream->list);
 470
 471         free(stream);
 472 }
 473
 474 /*
 475  * Cleanup kernel event structure.
 476  */
 477 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 478 {
 479         assert(event);
 480
 481         if (event->fd >= 0) {
 482                 int ret;
 483
 484                 DBG("[trace] Closing event fd %d", event->fd);
 485                 /* Close kernel fd */
 486                 ret = close(event->fd);
 487                 if (ret) {
 488                         PERROR("close");
 489                 }
 490         } else {
 491                 DBG("[trace] Tearing down event (no associated fd)");
 492         }
 493
 494         /* Remove from event list */
 495         cds_list_del(&event->list);
 496
 497         free(event->filter_expression);
 498         free(event->filter);
 499
 500         free(event->event);
 501         free(event);
 502 }
 503
 504 /*
 505  * Cleanup kernel context structure.
 506  */
 507 void trace_kernel_destroy_context(struct ltt_kernel_context *ctx)
 508 {
 509         assert(ctx);
 510
 511         if (ctx->in_list) {
 512                 cds_list_del(&ctx->list);
 513         }
 514         free(ctx);
 515 }
 516
 517 /*
 518  * Cleanup kernel channel structure.
 519  */
 520 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 521 {
 522         struct ltt_kernel_stream *stream, *stmp;
 523         struct ltt_kernel_event *event, *etmp;
 524         struct ltt_kernel_context *ctx, *ctmp;
 525         int ret;
 526         enum lttng_error_code status;
 527
 528         assert(channel);
 529
 530         DBG("[trace] Closing channel fd %d", channel->fd);
 531         /* Close kernel fd */
 532         if (channel->fd >= 0) {
 533                 ret = close(channel->fd);
 534                 if (ret) {
 535                         PERROR("close");
 536                 }
 537         }
 538
 539         /* For each stream in the channel list */
 540         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 541                 trace_kernel_destroy_stream(stream);
 542         }
 543
 544         /* For each event in the channel list */
 545         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 546                 trace_kernel_destroy_event(event);
 547         }
 548
 549         /* For each context in the channel list */
 550         cds_list_for_each_entry_safe(ctx, ctmp, &channel->ctx_list, list) {
 551                 trace_kernel_destroy_context(ctx);
 552         }
 553
 554         /* Remove from channel list */
 555         cds_list_del(&channel->list);
 556
 557         if (notification_thread_handle
 558                         && channel->published_to_notification_thread) {
 559                 status = notification_thread_command_remove_channel(
 560                                 notification_thread_handle,
 561                                 channel->key, LTTNG_DOMAIN_KERNEL);
 562                 assert(status == LTTNG_OK);
 563         }
 564         free(channel->channel->attr.extended.ptr);
 565         free(channel->channel);
 566         free(channel);
 567 }
 568
 569 /*
 570  * Cleanup kernel metadata structure.
 571  */
 572 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 573 {
 574         assert(metadata);
 575
 576         DBG("[trace] Closing metadata fd %d", metadata->fd);
 577         /* Close kernel fd */
 578         if (metadata->fd >= 0) {
 579                 int ret;
 580
 581                 ret = close(metadata->fd);
 582                 if (ret) {
 583                         PERROR("close");
 584                 }
 585         }
 586
 587         free(metadata->conf);
 588         free(metadata);
 589 }
 590
 591 /*
 592  * Cleanup kernel session structure
 593  *
 594  * Should *NOT* be called with RCU read-side lock held.
 595  */
 596 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 597 {
 598         struct ltt_kernel_channel *channel, *ctmp;
 599         int ret;
 600
 601         assert(session);
 602
 603         DBG("[trace] Closing session fd %d", session->fd);
 604         /* Close kernel fds */
 605         if (session->fd >= 0) {
 606                 ret = close(session->fd);
 607                 if (ret) {
 608                         PERROR("close");
 609                 }
 610         }
 611
 612         if (session->metadata_stream_fd >= 0) {
 613                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 614                 ret = close(session->metadata_stream_fd);
 615                 if (ret) {
 616                         PERROR("close");
 617                 }
 618         }
 619
 620         if (session->metadata != NULL) {
 621                 trace_kernel_destroy_metadata(session->metadata);
 622         }
 623
 624         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 625                 trace_kernel_destroy_channel(channel);
 626         }
 627
 628         /* Wipe consumer output object */
 629         consumer_output_put(session->consumer);
 630
 631         free(session);
 632 }