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 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev,
 296                 char *filter_expression, struct lttng_filter_bytecode *filter)
 297 {
 298         struct ltt_kernel_event *lke;
 299         struct lttng_kernel_event *attr;
 300
 301         assert(ev);
 302
 303         lke = zmalloc(sizeof(struct ltt_kernel_event));
 304         attr = zmalloc(sizeof(struct lttng_kernel_event));
 305         if (lke == NULL || attr == NULL) {
 306                 PERROR("kernel event zmalloc");
 307                 goto error;
 308         }
 309
 310         switch (ev->type) {
 311         case LTTNG_EVENT_PROBE:
 312                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 313                 attr->u.kprobe.addr = ev->attr.probe.addr;
 314                 attr->u.kprobe.offset = ev->attr.probe.offset;
 315                 strncpy(attr->u.kprobe.symbol_name,
 316                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 317                 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 318                 break;
 319         case LTTNG_EVENT_FUNCTION:
 320                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 321                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 322                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 323                 strncpy(attr->u.kretprobe.symbol_name,
 324                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 325                 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 326                 break;
 327         case LTTNG_EVENT_FUNCTION_ENTRY:
 328                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 329                 strncpy(attr->u.ftrace.symbol_name,
 330                                 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 331                 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 332                 break;
 333         case LTTNG_EVENT_TRACEPOINT:
 334                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 335                 break;
 336         case LTTNG_EVENT_SYSCALL:
 337                 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
 338                 break;
 339         case LTTNG_EVENT_ALL:
 340                 attr->instrumentation = LTTNG_KERNEL_ALL;
 341                 break;
 342         default:
 343                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 344                 goto error;
 345         }
 346
 347         /* Copy event name */
 348         strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
 349         attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 350
 351         /* Setting up a kernel event */
 352         lke->fd = -1;
 353         lke->event = attr;
 354         lke->enabled = 1;
 355         lke->filter_expression = filter_expression;
 356         lke->filter = filter;
 357
 358         return lke;
 359
 360 error:
 361         free(filter_expression);
 362         free(filter);
 363         free(lke);
 364         free(attr);
 365         return NULL;
 366 }
 367
 368 /*
 369  * Allocate and initialize a kernel metadata.
 370  *
 371  * Return pointer to structure or NULL.
 372  */
 373 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 374 {
 375         struct ltt_kernel_metadata *lkm;
 376         struct lttng_channel *chan;
 377
 378         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 379         chan = zmalloc(sizeof(struct lttng_channel));
 380         if (lkm == NULL || chan == NULL) {
 381                 PERROR("kernel metadata zmalloc");
 382                 goto error;
 383         }
 384
 385         /* Set default attributes */
 386         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 387         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 388         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 389         chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
 390         chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
 391         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 392
 393         /* Init metadata */
 394         lkm->fd = -1;
 395         lkm->conf = chan;
 396
 397         return lkm;
 398
 399 error:
 400         free(lkm);
 401         free(chan);
 402         return NULL;
 403 }
 404
 405 /*
 406  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 407  * default.
 408  *
 409  * Return pointer to structure or NULL.
 410  */
 411 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 412                 unsigned int count)
 413 {
 414         int ret;
 415         struct ltt_kernel_stream *lks;
 416
 417         assert(name);
 418
 419         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 420         if (lks == NULL) {
 421                 PERROR("kernel stream zmalloc");
 422                 goto error;
 423         }
 424
 425         /* Set name */
 426         ret = snprintf(lks->name, sizeof(lks->name), "%s_%u", name, count);
 427         if (ret < 0) {
 428                 PERROR("snprintf stream name");
 429                 goto error;
 430         }
 431         lks->name[sizeof(lks->name) - 1] = '\0';
 432
 433         /* Init stream */
 434         lks->fd = -1;
 435         lks->state = 0;
 436         lks->cpu = count;
 437
 438         return lks;
 439
 440 error:
 441         return NULL;
 442 }
 443
 444 /*
 445  * Cleanup kernel stream structure.
 446  */
 447 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 448 {
 449         assert(stream);
 450
 451         DBG("[trace] Closing stream fd %d", stream->fd);
 452         /* Close kernel fd */
 453         if (stream->fd >= 0) {
 454                 int ret;
 455
 456                 ret = close(stream->fd);
 457                 if (ret) {
 458                         PERROR("close");
 459                 }
 460         }
 461         /* Remove from stream list */
 462         cds_list_del(&stream->list);
 463
 464         free(stream);
 465 }
 466
 467 /*
 468  * Cleanup kernel event structure.
 469  */
 470 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 471 {
 472         assert(event);
 473
 474         if (event->fd >= 0) {
 475                 int ret;
 476
 477                 DBG("[trace] Closing event fd %d", event->fd);
 478                 /* Close kernel fd */
 479                 ret = close(event->fd);
 480                 if (ret) {
 481                         PERROR("close");
 482                 }
 483         } else {
 484                 DBG("[trace] Tearing down event (no associated fd)");
 485         }
 486
 487         /* Remove from event list */
 488         cds_list_del(&event->list);
 489
 490         free(event->filter_expression);
 491         free(event->filter);
 492
 493         free(event->event);
 494         free(event);
 495 }
 496
 497 /*
 498  * Cleanup kernel context structure.
 499  */
 500 void trace_kernel_destroy_context(struct ltt_kernel_context *ctx)
 501 {
 502         assert(ctx);
 503
 504         if (ctx->in_list) {
 505                 cds_list_del(&ctx->list);
 506         }
 507         free(ctx);
 508 }
 509
 510 /*
 511  * Cleanup kernel channel structure.
 512  */
 513 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 514 {
 515         struct ltt_kernel_stream *stream, *stmp;
 516         struct ltt_kernel_event *event, *etmp;
 517         struct ltt_kernel_context *ctx, *ctmp;
 518         int ret;
 519         enum lttng_error_code status;
 520
 521         assert(channel);
 522
 523         DBG("[trace] Closing channel fd %d", channel->fd);
 524         /* Close kernel fd */
 525         if (channel->fd >= 0) {
 526                 ret = close(channel->fd);
 527                 if (ret) {
 528                         PERROR("close");
 529                 }
 530         }
 531
 532         /* For each stream in the channel list */
 533         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 534                 trace_kernel_destroy_stream(stream);
 535         }
 536
 537         /* For each event in the channel list */
 538         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 539                 trace_kernel_destroy_event(event);
 540         }
 541
 542         /* For each context in the channel list */
 543         cds_list_for_each_entry_safe(ctx, ctmp, &channel->ctx_list, list) {
 544                 trace_kernel_destroy_context(ctx);
 545         }
 546
 547         /* Remove from channel list */
 548         cds_list_del(&channel->list);
 549
 550         if (notification_thread_handle
 551                         && channel->published_to_notification_thread) {
 552                 status = notification_thread_command_remove_channel(
 553                                 notification_thread_handle,
 554                                 channel->fd, LTTNG_DOMAIN_KERNEL);
 555                 assert(status == LTTNG_OK);
 556         }
 557         free(channel->channel->attr.extended.ptr);
 558         free(channel->channel);
 559         free(channel);
 560 }
 561
 562 /*
 563  * Cleanup kernel metadata structure.
 564  */
 565 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 566 {
 567         assert(metadata);
 568
 569         DBG("[trace] Closing metadata fd %d", metadata->fd);
 570         /* Close kernel fd */
 571         if (metadata->fd >= 0) {
 572                 int ret;
 573
 574                 ret = close(metadata->fd);
 575                 if (ret) {
 576                         PERROR("close");
 577                 }
 578         }
 579
 580         free(metadata->conf);
 581         free(metadata);
 582 }
 583
 584 /*
 585  * Cleanup kernel session structure
 586  *
 587  * Should *NOT* be called with RCU read-side lock held.
 588  */
 589 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 590 {
 591         struct ltt_kernel_channel *channel, *ctmp;
 592         int ret;
 593
 594         assert(session);
 595
 596         DBG("[trace] Closing session fd %d", session->fd);
 597         /* Close kernel fds */
 598         if (session->fd >= 0) {
 599                 ret = close(session->fd);
 600                 if (ret) {
 601                         PERROR("close");
 602                 }
 603         }
 604
 605         if (session->metadata_stream_fd >= 0) {
 606                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 607                 ret = close(session->metadata_stream_fd);
 608                 if (ret) {
 609                         PERROR("close");
 610                 }
 611         }
 612
 613         if (session->metadata != NULL) {
 614                 trace_kernel_destroy_metadata(session->metadata);
 615         }
 616
 617         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 618                 trace_kernel_destroy_channel(channel);
 619         }
 620
 621         /* Wipe consumer output object */
 622         consumer_output_put(session->consumer);
 623
 624         free(session);
 625 }