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;
 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         /* Init linked list */
 225         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 226         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 227         CDS_INIT_LIST_HEAD(&lkc->ctx_list);
 228
 229         return lkc;
 230
 231 error:
 232         if (lkc) {
 233                 free(lkc->channel);
 234         }
 235         free(extended);
 236         free(lkc);
 237         return NULL;
 238 }
 239
 240 /*
 241  * Allocate and init a kernel context object.
 242  *
 243  * Return the allocated object or NULL on error.
 244  */
 245 struct ltt_kernel_context *trace_kernel_create_context(
 246                 struct lttng_kernel_context *ctx)
 247 {
 248         struct ltt_kernel_context *kctx;
 249
 250         kctx = zmalloc(sizeof(*kctx));
 251         if (!kctx) {
 252                 PERROR("zmalloc kernel context");
 253                 goto error;
 254         }
 255
 256         if (ctx) {
 257                 memcpy(&kctx->ctx, ctx, sizeof(kctx->ctx));
 258         }
 259
 260         CDS_INIT_LIST_HEAD(&kctx->list);
 261
 262 error:
 263         return kctx;
 264 }
 265
 266 /*
 267  * Allocate and initialize a kernel event. Set name and event type.
 268  * We own filter_expression, and filter.
 269  *
 270  * Return pointer to structure or NULL.
 271  */
 272 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev,
 273                 char *filter_expression, struct lttng_filter_bytecode *filter)
 274 {
 275         struct ltt_kernel_event *lke;
 276         struct lttng_kernel_event *attr;
 277
 278         assert(ev);
 279
 280         lke = zmalloc(sizeof(struct ltt_kernel_event));
 281         attr = zmalloc(sizeof(struct lttng_kernel_event));
 282         if (lke == NULL || attr == NULL) {
 283                 PERROR("kernel event zmalloc");
 284                 goto error;
 285         }
 286
 287         switch (ev->type) {
 288         case LTTNG_EVENT_PROBE:
 289                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 290                 attr->u.kprobe.addr = ev->attr.probe.addr;
 291                 attr->u.kprobe.offset = ev->attr.probe.offset;
 292                 strncpy(attr->u.kprobe.symbol_name,
 293                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 294                 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 295                 break;
 296         case LTTNG_EVENT_FUNCTION:
 297                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 298                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 299                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 300                 strncpy(attr->u.kretprobe.symbol_name,
 301                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 302                 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 303                 break;
 304         case LTTNG_EVENT_FUNCTION_ENTRY:
 305                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 306                 strncpy(attr->u.ftrace.symbol_name,
 307                                 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 308                 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 309                 break;
 310         case LTTNG_EVENT_TRACEPOINT:
 311                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 312                 break;
 313         case LTTNG_EVENT_SYSCALL:
 314                 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
 315                 break;
 316         case LTTNG_EVENT_ALL:
 317                 attr->instrumentation = LTTNG_KERNEL_ALL;
 318                 break;
 319         default:
 320                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 321                 goto error;
 322         }
 323
 324         /* Copy event name */
 325         strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
 326         attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 327
 328         /* Setting up a kernel event */
 329         lke->fd = -1;
 330         lke->event = attr;
 331         lke->enabled = 1;
 332         lke->filter_expression = filter_expression;
 333         lke->filter = filter;
 334
 335         return lke;
 336
 337 error:
 338         free(filter_expression);
 339         free(filter);
 340         free(lke);
 341         free(attr);
 342         return NULL;
 343 }
 344
 345 /*
 346  * Allocate and initialize a kernel metadata.
 347  *
 348  * Return pointer to structure or NULL.
 349  */
 350 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 351 {
 352         struct ltt_kernel_metadata *lkm;
 353         struct lttng_channel *chan;
 354
 355         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 356         chan = zmalloc(sizeof(struct lttng_channel));
 357         if (lkm == NULL || chan == NULL) {
 358                 PERROR("kernel metadata zmalloc");
 359                 goto error;
 360         }
 361
 362         /* Set default attributes */
 363         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 364         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 365         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 366         chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
 367         chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
 368         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 369
 370         /* Init metadata */
 371         lkm->fd = -1;
 372         lkm->conf = chan;
 373
 374         return lkm;
 375
 376 error:
 377         free(lkm);
 378         free(chan);
 379         return NULL;
 380 }
 381
 382 /*
 383  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 384  * default.
 385  *
 386  * Return pointer to structure or NULL.
 387  */
 388 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 389                 unsigned int count)
 390 {
 391         int ret;
 392         struct ltt_kernel_stream *lks;
 393
 394         assert(name);
 395
 396         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 397         if (lks == NULL) {
 398                 PERROR("kernel stream zmalloc");
 399                 goto error;
 400         }
 401
 402         /* Set name */
 403         ret = snprintf(lks->name, sizeof(lks->name), "%s_%u", name, count);
 404         if (ret < 0) {
 405                 PERROR("snprintf stream name");
 406                 goto error;
 407         }
 408         lks->name[sizeof(lks->name) - 1] = '\0';
 409
 410         /* Init stream */
 411         lks->fd = -1;
 412         lks->state = 0;
 413         lks->cpu = count;
 414
 415         return lks;
 416
 417 error:
 418         return NULL;
 419 }
 420
 421 /*
 422  * Cleanup kernel stream structure.
 423  */
 424 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 425 {
 426         assert(stream);
 427
 428         DBG("[trace] Closing stream fd %d", stream->fd);
 429         /* Close kernel fd */
 430         if (stream->fd >= 0) {
 431                 int ret;
 432
 433                 ret = close(stream->fd);
 434                 if (ret) {
 435                         PERROR("close");
 436                 }
 437         }
 438         /* Remove from stream list */
 439         cds_list_del(&stream->list);
 440
 441         free(stream);
 442 }
 443
 444 /*
 445  * Cleanup kernel event structure.
 446  */
 447 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 448 {
 449         assert(event);
 450
 451         if (event->fd >= 0) {
 452                 int ret;
 453
 454                 DBG("[trace] Closing event fd %d", event->fd);
 455                 /* Close kernel fd */
 456                 ret = close(event->fd);
 457                 if (ret) {
 458                         PERROR("close");
 459                 }
 460         } else {
 461                 DBG("[trace] Tearing down event (no associated fd)");
 462         }
 463
 464         /* Remove from event list */
 465         cds_list_del(&event->list);
 466
 467         free(event->filter_expression);
 468         free(event->filter);
 469
 470         free(event->event);
 471         free(event);
 472 }
 473
 474 /*
 475  * Cleanup kernel context structure.
 476  */
 477 void trace_kernel_destroy_context(struct ltt_kernel_context *ctx)
 478 {
 479         assert(ctx);
 480
 481         cds_list_del(&ctx->list);
 482         free(ctx);
 483 }
 484
 485 /*
 486  * Cleanup kernel channel structure.
 487  */
 488 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 489 {
 490         struct ltt_kernel_stream *stream, *stmp;
 491         struct ltt_kernel_event *event, *etmp;
 492         struct ltt_kernel_context *ctx, *ctmp;
 493         int ret;
 494         enum lttng_error_code status;
 495
 496         assert(channel);
 497
 498         DBG("[trace] Closing channel fd %d", channel->fd);
 499         /* Close kernel fd */
 500         if (channel->fd >= 0) {
 501                 ret = close(channel->fd);
 502                 if (ret) {
 503                         PERROR("close");
 504                 }
 505         }
 506
 507         /* For each stream in the channel list */
 508         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 509                 trace_kernel_destroy_stream(stream);
 510         }
 511
 512         /* For each event in the channel list */
 513         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 514                 trace_kernel_destroy_event(event);
 515         }
 516
 517         /* For each context in the channel list */
 518         cds_list_for_each_entry_safe(ctx, ctmp, &channel->ctx_list, list) {
 519                 trace_kernel_destroy_context(ctx);
 520         }
 521
 522         /* Remove from channel list */
 523         cds_list_del(&channel->list);
 524
 525         if (notification_thread_handle) {
 526                 status = notification_thread_command_remove_channel(
 527                                 notification_thread_handle,
 528                                 channel->fd, LTTNG_DOMAIN_KERNEL);
 529                 assert(status == LTTNG_OK);
 530         }
 531         free(channel->channel->attr.extended.ptr);
 532         free(channel->channel);
 533         free(channel);
 534 }
 535
 536 /*
 537  * Cleanup kernel metadata structure.
 538  */
 539 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 540 {
 541         assert(metadata);
 542
 543         DBG("[trace] Closing metadata fd %d", metadata->fd);
 544         /* Close kernel fd */
 545         if (metadata->fd >= 0) {
 546                 int ret;
 547
 548                 ret = close(metadata->fd);
 549                 if (ret) {
 550                         PERROR("close");
 551                 }
 552         }
 553
 554         free(metadata->conf);
 555         free(metadata);
 556 }
 557
 558 /*
 559  * Cleanup kernel session structure
 560  *
 561  * Should *NOT* be called with RCU read-side lock held.
 562  */
 563 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 564 {
 565         struct ltt_kernel_channel *channel, *ctmp;
 566         int ret;
 567
 568         assert(session);
 569
 570         DBG("[trace] Closing session fd %d", session->fd);
 571         /* Close kernel fds */
 572         if (session->fd >= 0) {
 573                 ret = close(session->fd);
 574                 if (ret) {
 575                         PERROR("close");
 576                 }
 577         }
 578
 579         if (session->metadata_stream_fd >= 0) {
 580                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 581                 ret = close(session->metadata_stream_fd);
 582                 if (ret) {
 583                         PERROR("close");
 584                 }
 585         }
 586
 587         if (session->metadata != NULL) {
 588                 trace_kernel_destroy_metadata(session->metadata);
 589         }
 590
 591         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 592                 trace_kernel_destroy_channel(channel);
 593         }
 594
 595         /* Wipe consumer output object */
 596         consumer_output_put(session->consumer);
 597
 598         free(session);
 599 }