ltt-sessiond/kernel-ctl.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
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include "lttngerr.h"
  28 #include "libkernelctl.h"
  29 #include "kernel-ctl.h"
  30
  31 /*
  32  *  kernel_add_channel_context
  33  *
  34  *  Add context on a kernel channel.
  35  */
  36 int kernel_add_channel_context(struct ltt_kernel_channel *chan,
  37                 struct lttng_kernel_context *ctx)
  38 {
  39         int ret;
  40
  41         DBG("Adding context to channel %s", chan->channel->name);
  42         ret = kernctl_add_context(chan->fd, ctx);
  43         if (ret < 0) {
  44                 perror("add context ioctl");
  45                 goto error;
  46         }
  47
  48         chan->ctx = malloc(sizeof(struct lttng_kernel_context));
  49         if (chan->ctx == NULL) {
  50                 perror("malloc event context");
  51                 goto error;
  52         }
  53
  54         memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
  55
  56         return 0;
  57
  58 error:
  59         return ret;
  60 }
  61
  62 /*
  63  *  kernel_add_event_context
  64  *
  65  *  Add context on a kernel event.
  66  */
  67 int kernel_add_event_context(struct ltt_kernel_event *event,
  68                 struct lttng_kernel_context *ctx)
  69 {
  70         int ret;
  71
  72         DBG("Adding context to event %s", event->event->name);
  73         ret = kernctl_add_context(event->fd, ctx);
  74         if (ret < 0) {
  75                 perror("add context ioctl");
  76                 goto error;
  77         }
  78
  79         event->ctx = malloc(sizeof(struct lttng_kernel_context));
  80         if (event->ctx == NULL) {
  81                 perror("malloc event context");
  82                 goto error;
  83         }
  84
  85         memcpy(event->ctx, ctx, sizeof(struct lttng_kernel_context));
  86
  87         return 0;
  88
  89 error:
  90         return ret;
  91 }
  92
  93 /*
  94  *  kernel_create_session
  95  *
  96  *  Create a new kernel session, register it to the kernel tracer and add it to
  97  *  the session daemon session.
  98  */
  99 int kernel_create_session(struct ltt_session *session, int tracer_fd)
 100 {
 101         int ret;
 102         struct ltt_kernel_session *lks;
 103
 104         /* Allocate data structure */
 105         lks = trace_create_kernel_session();
 106         if (lks == NULL) {
 107                 ret = -1;
 108                 goto error;
 109         }
 110
 111         /* Kernel tracer session creation */
 112         ret = kernctl_create_session(tracer_fd);
 113         if (ret < 0) {
 114                 perror("ioctl kernel create session");
 115                 goto error;
 116         }
 117
 118         lks->fd = ret;
 119         /* Prevent fd duplication after execlp() */
 120         ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
 121         if (ret < 0) {
 122                 perror("fcntl session fd");
 123         }
 124
 125         lks->kconsumer_fds_sent = 0;
 126         session->kernel_session = lks;
 127         session->kern_session_count++;
 128
 129         DBG("Kernel session created (fd: %d)", lks->fd);
 130
 131         return 0;
 132
 133 error:
 134         return ret;
 135 }
 136
 137 /*
 138  *  kernel_create_channel
 139  *
 140  *  Create a kernel channel, register it to the kernel tracer and add it to the
 141  *  kernel session.
 142  */
 143 int kernel_create_channel(struct ltt_kernel_session *session, struct lttng_channel *chan, char *path)
 144 {
 145         int ret;
 146         struct ltt_kernel_channel *lkc;
 147
 148         /* Allocate kernel channel */
 149         lkc = trace_create_kernel_channel(chan, path);
 150         if (lkc == NULL) {
 151                 goto error;
 152         }
 153
 154         /* Kernel tracer channel creation */
 155         ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
 156         if (ret < 0) {
 157                 perror("ioctl kernel create channel");
 158                 goto error;
 159         }
 160
 161         /* Setup the channel fd */
 162         lkc->fd = ret;
 163         /* Prevent fd duplication after execlp() */
 164         ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC);
 165         if (ret < 0) {
 166                 perror("fcntl session fd");
 167         }
 168
 169         /* Add channel to session */
 170         cds_list_add(&lkc->list, &session->channel_list.head);
 171         session->channel_count++;
 172
 173         DBG("Kernel channel %s created (fd: %d and path: %s)",
 174                         lkc->channel->name, lkc->fd, lkc->pathname);
 175
 176         return 0;
 177
 178 error:
 179         return -1;
 180 }
 181
 182 /*
 183  *  kernel_create_event
 184  *
 185  *  Create a kernel event, enable it to the kernel tracer and add it to the
 186  *  channel event list of the kernel session.
 187  */
 188 int kernel_create_event(struct lttng_event *ev, struct ltt_kernel_channel *channel)
 189 {
 190         int ret;
 191         struct ltt_kernel_event *event;
 192
 193         event = trace_create_kernel_event(ev);
 194         if (event == NULL) {
 195                 goto error;
 196         }
 197
 198         ret = kernctl_create_event(channel->fd, event->event);
 199         if (ret < 0) {
 200                 perror("create event ioctl");
 201                 goto free_event;
 202         }
 203
 204         event->fd = ret;
 205         /* Prevent fd duplication after execlp() */
 206         ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
 207         if (ret < 0) {
 208                 perror("fcntl session fd");
 209         }
 210
 211         /* Add event to event list */
 212         cds_list_add(&event->list, &channel->events_list.head);
 213         DBG("Event %s created (fd: %d)", ev->name, event->fd);
 214
 215         return 0;
 216
 217 free_event:
 218         free(event);
 219 error:
 220         return -1;
 221 }
 222
 223 /*
 224  *  kernel_disable_channel
 225  *
 226  *  Disable a kernel channel.
 227  */
 228 int kernel_disable_channel(struct ltt_kernel_channel *chan)
 229 {
 230         int ret;
 231
 232         ret = kernctl_disable(chan->fd);
 233         if (ret < 0) {
 234                 perror("disable chan ioctl");
 235                 ret = errno;
 236                 goto error;
 237         }
 238
 239         chan->enabled = 0;
 240         DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
 241
 242         return 0;
 243
 244 error:
 245         return ret;
 246 }
 247
 248 /*
 249  *  kernel_enable_channel
 250  *
 251  *  Enable a kernel channel.
 252  */
 253 int kernel_enable_channel(struct ltt_kernel_channel *chan)
 254 {
 255         int ret;
 256
 257         ret = kernctl_enable(chan->fd);
 258         if (ret < 0) {
 259                 perror("enable chan ioctl");
 260                 ret = errno;
 261                 goto error;
 262         }
 263
 264         chan->enabled = 1;
 265         DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
 266
 267         return 0;
 268
 269 error:
 270         return ret;
 271 }
 272
 273 /*
 274  *  kernel_enable_event
 275  *
 276  *  Enable a kernel event.
 277  */
 278 int kernel_enable_event(struct ltt_kernel_event *event)
 279 {
 280         int ret;
 281
 282         ret = kernctl_enable(event->fd);
 283         if (ret < 0) {
 284                 perror("enable event ioctl");
 285                 goto error;
 286         }
 287
 288         event->enabled = 1;
 289         DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd);
 290
 291         return 0;
 292
 293 error:
 294         return ret;
 295 }
 296
 297 /*
 298  *  kernel_disable_event
 299  *
 300  *  Disable a kernel event.
 301  */
 302 int kernel_disable_event(struct ltt_kernel_event *event)
 303 {
 304         int ret;
 305
 306         ret = kernctl_disable(event->fd);
 307         if (ret < 0) {
 308                 perror("disable event ioctl");
 309                 goto error;
 310         }
 311
 312         event->enabled = 0;
 313         DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
 314
 315         return 0;
 316
 317 error:
 318         return ret;
 319 }
 320
 321 /*
 322  *  kernel_open_metadata
 323  *
 324  *  Create kernel metadata, open from the kernel tracer and add it to the
 325  *  kernel session.
 326  */
 327 int kernel_open_metadata(struct ltt_kernel_session *session, char *path)
 328 {
 329         int ret;
 330         struct ltt_kernel_metadata *lkm;
 331
 332         /* Allocate kernel metadata */
 333         lkm = trace_create_kernel_metadata(path);
 334         if (lkm == NULL) {
 335                 goto error;
 336         }
 337
 338         /* Kernel tracer metadata creation */
 339         ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
 340         if (ret < 0) {
 341                 goto error;
 342         }
 343
 344         lkm->fd = ret;
 345         /* Prevent fd duplication after execlp() */
 346         ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
 347         if (ret < 0) {
 348                 perror("fcntl session fd");
 349         }
 350
 351         session->metadata = lkm;
 352
 353         DBG("Kernel metadata opened (fd: %d and path: %s)", lkm->fd, lkm->pathname);
 354
 355         return 0;
 356
 357 error:
 358         return -1;
 359 }
 360
 361 /*
 362  *  kernel_start_session
 363  *
 364  *  Start tracing session.
 365  */
 366 int kernel_start_session(struct ltt_kernel_session *session)
 367 {
 368         int ret;
 369
 370         ret = kernctl_start_session(session->fd);
 371         if (ret < 0) {
 372                 perror("ioctl start session");
 373                 goto error;
 374         }
 375
 376         DBG("Kernel session started");
 377
 378         return 0;
 379
 380 error:
 381         return ret;
 382 }
 383
 384 /*
 385  *  kernel_wait_quiescent
 386  *
 387  *  Make a kernel wait to make sure in-flight probe have completed.
 388  */
 389 void kernel_wait_quiescent(int fd)
 390 {
 391         int ret;
 392
 393         DBG("Kernel quiescent wait on %d", fd);
 394
 395         ret = kernctl_wait_quiescent(fd);
 396         if (ret < 0) {
 397                 perror("wait quiescent ioctl");
 398                 ERR("Kernel quiescent wait failed");
 399         }
 400 }
 401
 402 /*
 403  *  kernel_metadata_flush_buffer
 404  *
 405  *  Force flush buffer of metadata.
 406  */
 407 int kernel_metadata_flush_buffer(int fd)
 408 {
 409         int ret;
 410
 411         ret = kernctl_buffer_flush(fd);
 412         if (ret < 0) {
 413                 ERR("Fail to flush metadata buffers %d (ret: %d", fd, ret);
 414         }
 415
 416         return 0;
 417 }
 418
 419 /*
 420  *  kernel_flush_buffer
 421  *
 422  *  Force flush buffer for channel.
 423  */
 424 int kernel_flush_buffer(struct ltt_kernel_channel *channel)
 425 {
 426         int ret;
 427         struct ltt_kernel_stream *stream;
 428
 429         DBG("Flush buffer for channel %s", channel->channel->name);
 430
 431         cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
 432                 DBG("Flushing channel stream %d", stream->fd);
 433                 ret = kernctl_buffer_flush(stream->fd);
 434                 if (ret < 0) {
 435                         perror("ioctl");
 436                         ERR("Fail to flush buffer for stream %d (ret: %d)",
 437                                         stream->fd, ret);
 438                 }
 439         }
 440
 441         return 0;
 442 }
 443
 444 /*
 445  *  kernel_stop_session
 446  *
 447  *  Stop tracing session.
 448  */
 449 int kernel_stop_session(struct ltt_kernel_session *session)
 450 {
 451         int ret;
 452
 453         ret = kernctl_stop_session(session->fd);
 454         if (ret < 0) {
 455                 goto error;
 456         }
 457
 458         DBG("Kernel session stopped");
 459
 460         return 0;
 461
 462 error:
 463         return ret;
 464 }
 465
 466 /*
 467  *  kernel_open_channel_stream
 468  *
 469  *  Open stream of channel, register it to the kernel tracer and add it
 470  *  to the stream list of the channel.
 471  *
 472  *  Return the number of created stream. Else, a negative value.
 473  */
 474 int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
 475 {
 476         int ret;
 477         struct ltt_kernel_stream *lks;
 478
 479         while ((ret = kernctl_create_stream(channel->fd)) > 0) {
 480                 lks = trace_create_kernel_stream();
 481                 if (lks == NULL) {
 482                         close(ret);
 483                         goto error;
 484                 }
 485
 486                 lks->fd = ret;
 487                 /* Prevent fd duplication after execlp() */
 488                 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
 489                 if (ret < 0) {
 490                         perror("fcntl session fd");
 491                 }
 492
 493                 ret = asprintf(&lks->pathname, "%s/%s_%d",
 494                                 channel->pathname, channel->channel->name, channel->stream_count);
 495                 if (ret < 0) {
 496                         perror("asprintf kernel create stream");
 497                         goto error;
 498                 }
 499
 500                 /* Add stream to channe stream list */
 501                 cds_list_add(&lks->list, &channel->stream_list.head);
 502                 channel->stream_count++;
 503
 504                 DBG("Kernel stream %d created (fd: %d, state: %d, path: %s)",
 505                                 channel->stream_count, lks->fd, lks->state, lks->pathname);
 506         }
 507
 508         return channel->stream_count;
 509
 510 error:
 511         return -1;
 512 }
 513
 514 /*
 515  *  kernel_open_metadata_stream
 516  *
 517  *  Open the metadata stream and set it to the kernel session.
 518  */
 519 int kernel_open_metadata_stream(struct ltt_kernel_session *session)
 520 {
 521         int ret;
 522
 523         ret = kernctl_create_stream(session->metadata->fd);
 524         if (ret < 0) {
 525                 perror("kernel create metadata stream");
 526                 goto error;
 527         }
 528
 529         DBG("Kernel metadata stream created (fd: %d)", ret);
 530         session->metadata_stream_fd = ret;
 531         /* Prevent fd duplication after execlp() */
 532         ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC);
 533         if (ret < 0) {
 534                 perror("fcntl session fd");
 535         }
 536
 537         return 0;
 538
 539 error:
 540         return -1;
 541 }
 542
 543 /*
 544  *  kernel_list_events
 545  *
 546  *  Get the event list from the kernel tracer and return that list in the CTF
 547  *  format.
 548  */
 549 ssize_t kernel_list_events(int tracer_fd, char **list)
 550 {
 551         int fd;
 552         char *buf, *line = NULL;
 553         size_t nb, nbmem, total = 0;
 554         ssize_t size;
 555         FILE *fp;
 556
 557         fd = kernctl_tracepoint_list(tracer_fd);
 558         if (fd < 0) {
 559                 perror("kernel tracepoint list");
 560                 goto error;
 561         }
 562
 563         fp = fdopen(fd, "r");
 564         if (fp == NULL) {
 565                 perror("kernel tracepoint list fdopen");
 566                 goto error;
 567         }
 568
 569         /*
 570          * Init memory size counter
 571          * See kernel-ctl.h for explanation of this value
 572          */
 573         nbmem = KERNEL_EVENT_LIST_SIZE;
 574         buf = malloc(nbmem);
 575
 576         while ((size = getline(&line, &nb, fp)) != -1) {
 577                 if (total + size > nbmem) {
 578                         DBG("Reallocating event list from %zd to %zd bytes", nbmem,
 579                                         total + size + KERNEL_EVENT_LIST_SIZE);
 580                         /* Adding the default size again */
 581                         nbmem = total + size + KERNEL_EVENT_LIST_SIZE;
 582                         buf = realloc(buf, nbmem);
 583                         if (buf == NULL) {
 584                                 perror("realloc list events");
 585                                 goto error;
 586                         }
 587                 }
 588                 memcpy(buf + total, line, size);
 589                 total += size;
 590         }
 591
 592         *list = buf;
 593
 594         DBG("Kernel list events done");
 595
 596         return total;
 597
 598 error:
 599         return -1;
 600 }