src/common/kernel-ctl/kernel-ctl.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *               2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _LGPL_SOURCE
  21 #define __USE_LINUX_IOCTL_DEFS
  22 #include <sys/ioctl.h>
  23 #include <string.h>
  24 #include <common/align.h>
  25 #include <common/macros.h>
  26 #include <errno.h>
  27 #include <stdarg.h>
  28 #include <assert.h>
  29 #include <common/time.h>
  30
  31 #include "kernel-ctl.h"
  32 #include "kernel-ioctl.h"
  33
  34 #define LTTNG_IOCTL_CHECK(fildes, request, ...) ({      \
  35         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  36         assert(ret <= 0);                               \
  37         !ret ? 0 : -errno;                              \
  38 })
  39
  40 #define LTTNG_IOCTL_NO_CHECK(fildes, request, ...) ({   \
  41         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  42         ret >= 0 ? ret : -errno;                        \
  43 })
  44
  45 /*
  46  * This flag indicates which version of the kernel ABI to use. The old
  47  * ABI (namespace _old) does not support a 32-bit user-space when the
  48  * kernel is 64-bit. The old ABI is kept here for compatibility but is
  49  * deprecated and will be removed eventually.
  50  */
  51 static int lttng_kernel_use_old_abi = -1;
  52
  53 /*
  54  * Execute the new or old ioctl depending on the ABI version.
  55  * If the ABI version is not determined yet (lttng_kernel_use_old_abi = -1),
  56  * this function tests if the new ABI is available and otherwise fallbacks
  57  * on the old one.
  58  * This function takes the fd on which the ioctl must be executed and the old
  59  * and new request codes.
  60  * It returns the return value of the ioctl executed.
  61  */
  62 static inline int compat_ioctl_no_arg(int fd, unsigned long oldname,
  63                 unsigned long newname)
  64 {
  65         int ret;
  66
  67         if (lttng_kernel_use_old_abi == -1) {
  68                 ret = LTTNG_IOCTL_NO_CHECK(fd, newname);
  69                 if (!ret) {
  70                         lttng_kernel_use_old_abi = 0;
  71                         goto end;
  72                 }
  73                 lttng_kernel_use_old_abi = 1;
  74         }
  75         if (lttng_kernel_use_old_abi) {
  76                 ret = LTTNG_IOCTL_NO_CHECK(fd, oldname);
  77         } else {
  78                 ret = LTTNG_IOCTL_NO_CHECK(fd, newname);
  79         }
  80
  81 end:
  82         return ret;
  83 }
  84
  85 int kernctl_create_session(int fd)
  86 {
  87         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION,
  88                         LTTNG_KERNEL_SESSION);
  89 }
  90
  91 /* open the metadata global channel */
  92 int kernctl_open_metadata(int fd, struct lttng_channel_attr *chops)
  93 {
  94         struct lttng_kernel_channel channel;
  95
  96         if (lttng_kernel_use_old_abi) {
  97                 struct lttng_kernel_old_channel old_channel;
  98
  99                 memset(&old_channel, 0, sizeof(old_channel));
 100                 old_channel.overwrite = chops->overwrite;
 101                 old_channel.subbuf_size = chops->subbuf_size;
 102                 old_channel.num_subbuf = chops->num_subbuf;
 103                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 104                 old_channel.read_timer_interval = chops->read_timer_interval;
 105                 old_channel.output = chops->output;
 106
 107                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 108                 /*
 109                  * The new channel padding is smaller than the old ABI so we use the
 110                  * new ABI padding size for the memcpy.
 111                  */
 112                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 113
 114                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_METADATA,
 115                                 &old_channel);
 116         }
 117
 118         memset(&channel, 0, sizeof(channel));
 119         channel.overwrite = chops->overwrite;
 120         channel.subbuf_size = chops->subbuf_size;
 121         channel.num_subbuf = chops->num_subbuf;
 122         channel.switch_timer_interval = chops->switch_timer_interval;
 123         channel.read_timer_interval = chops->read_timer_interval;
 124         channel.output = chops->output;
 125         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 126
 127         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_METADATA, &channel);
 128 }
 129
 130 int kernctl_create_channel(int fd, struct lttng_channel_attr *chops)
 131 {
 132         struct lttng_kernel_channel channel;
 133
 134         memset(&channel, 0, sizeof(channel));
 135         if (lttng_kernel_use_old_abi) {
 136                 struct lttng_kernel_old_channel old_channel;
 137
 138                 old_channel.overwrite = chops->overwrite;
 139                 old_channel.subbuf_size = chops->subbuf_size;
 140                 old_channel.num_subbuf = chops->num_subbuf;
 141                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 142                 old_channel.read_timer_interval = chops->read_timer_interval;
 143                 old_channel.output = chops->output;
 144
 145                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 146                 /*
 147                  * The new channel padding is smaller than the old ABI so we use the
 148                  * new ABI padding size for the memcpy.
 149                  */
 150                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 151
 152                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_CHANNEL,
 153                                 &old_channel);
 154         }
 155
 156         channel.overwrite = chops->overwrite;
 157         channel.subbuf_size = chops->subbuf_size;
 158         channel.num_subbuf = chops->num_subbuf;
 159         channel.switch_timer_interval = chops->switch_timer_interval;
 160         channel.read_timer_interval = chops->read_timer_interval;
 161         channel.output = chops->output;
 162         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 163
 164         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_CHANNEL, &channel);
 165 }
 166
 167 int kernctl_syscall_mask(int fd, char **syscall_mask, uint32_t *nr_bits)
 168 {
 169         struct lttng_kernel_syscall_mask kmask_len, *kmask = NULL;
 170         size_t array_alloc_len;
 171         char *new_mask;
 172         int ret = 0;
 173
 174         if (!syscall_mask) {
 175                 ret = -1;
 176                 goto end;
 177         }
 178
 179         if (!nr_bits) {
 180                 ret = -1;
 181                 goto end;
 182         }
 183
 184         kmask_len.len = 0;
 185         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SYSCALL_MASK, &kmask_len);
 186         if (ret) {
 187                 goto end;
 188         }
 189
 190         array_alloc_len = ALIGN(kmask_len.len, 8) >> 3;
 191
 192         kmask = zmalloc(sizeof(*kmask) + array_alloc_len);
 193         if (!kmask) {
 194                 ret = -1;
 195                 goto end;
 196         }
 197
 198         kmask->len = kmask_len.len;
 199         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SYSCALL_MASK, kmask);
 200         if (ret) {
 201                 goto end;
 202         }
 203
 204         new_mask = realloc(*syscall_mask, array_alloc_len);
 205         if (!new_mask) {
 206                 ret = -1;
 207                 goto end;
 208         }
 209         memcpy(new_mask, kmask->mask, array_alloc_len);
 210         *syscall_mask = new_mask;
 211         *nr_bits = kmask->len;
 212
 213 end:
 214         free(kmask);
 215         return ret;
 216 }
 217
 218 int kernctl_track_pid(int fd, int pid)
 219 {
 220         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_TRACK_PID, pid);
 221 }
 222
 223 int kernctl_untrack_pid(int fd, int pid)
 224 {
 225         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_UNTRACK_PID, pid);
 226 }
 227
 228 int kernctl_list_tracker_pids(int fd)
 229 {
 230         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS);
 231 }
 232
 233 int kernctl_session_regenerate_metadata(int fd)
 234 {
 235         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_METADATA_REGEN);
 236 }
 237
 238 int kernctl_session_regenerate_statedump(int fd)
 239 {
 240         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_STATEDUMP);
 241 }
 242
 243 int kernctl_session_set_name(int fd, const char *name)
 244 {
 245         int ret;
 246         struct lttng_kernel_session_name session_name;
 247
 248         ret = lttng_strncpy(session_name.name, name, sizeof(session_name.name));
 249         if (ret) {
 250                 goto end;
 251         }
 252
 253         ret = LTTNG_IOCTL_CHECK(
 254                         fd, LTTNG_KERNEL_SESSION_SET_NAME, &session_name);
 255 end:
 256         return ret;
 257 }
 258
 259 int kernctl_session_set_creation_time(int fd, time_t time)
 260 {
 261         int ret;
 262         struct lttng_kernel_session_creation_time creation_time;
 263
 264         ret = time_to_iso8601_str(time, creation_time.iso8601,
 265                         sizeof(creation_time.iso8601));
 266         if (ret) {
 267                 goto end;
 268         }
 269
 270         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_SET_CREATION_TIME,
 271                         &creation_time);
 272 end:
 273         return ret;
 274 }
 275
 276 int kernctl_create_stream(int fd)
 277 {
 278         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 279                         LTTNG_KERNEL_STREAM);
 280 }
 281
 282 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 283 {
 284         if (lttng_kernel_use_old_abi) {
 285                 struct lttng_kernel_old_event old_event;
 286
 287                 memset(&old_event, 0, sizeof(old_event));
 288                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 289                 old_event.instrumentation = ev->instrumentation;
 290                 switch (ev->instrumentation) {
 291                 case LTTNG_KERNEL_KPROBE:
 292                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 293                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 294                         memcpy(old_event.u.kprobe.symbol_name,
 295                                 ev->u.kprobe.symbol_name,
 296                                 sizeof(old_event.u.kprobe.symbol_name));
 297                         break;
 298                 case LTTNG_KERNEL_KRETPROBE:
 299                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 300                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 301                         memcpy(old_event.u.kretprobe.symbol_name,
 302                                 ev->u.kretprobe.symbol_name,
 303                                 sizeof(old_event.u.kretprobe.symbol_name));
 304                         break;
 305                 case LTTNG_KERNEL_FUNCTION:
 306                         memcpy(old_event.u.ftrace.symbol_name,
 307                                         ev->u.ftrace.symbol_name,
 308                                         sizeof(old_event.u.ftrace.symbol_name));
 309                         break;
 310                 default:
 311                         break;
 312                 }
 313
 314                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_EVENT,
 315                                 &old_event);
 316         }
 317         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_EVENT, ev);
 318 }
 319
 320 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 321 {
 322         if (lttng_kernel_use_old_abi) {
 323                 struct lttng_kernel_old_context old_ctx;
 324
 325                 memset(&old_ctx, 0, sizeof(old_ctx));
 326                 old_ctx.ctx = ctx->ctx;
 327                 /* only type that uses the union */
 328                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 329                         old_ctx.u.perf_counter.type =
 330                                 ctx->u.perf_counter.type;
 331                         old_ctx.u.perf_counter.config =
 332                                 ctx->u.perf_counter.config;
 333                         memcpy(old_ctx.u.perf_counter.name,
 334                                 ctx->u.perf_counter.name,
 335                                 sizeof(old_ctx.u.perf_counter.name));
 336                 }
 337                 return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 338         }
 339         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_CONTEXT, ctx);
 340 }
 341
 342
 343 /* Enable event, channel and session LTTNG_IOCTL_CHECK */
 344 int kernctl_enable(int fd)
 345 {
 346         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 347                         LTTNG_KERNEL_ENABLE);
 348 }
 349
 350 /* Disable event, channel and session LTTNG_IOCTL_CHECK */
 351 int kernctl_disable(int fd)
 352 {
 353         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 354                         LTTNG_KERNEL_DISABLE);
 355 }
 356
 357 int kernctl_start_session(int fd)
 358 {
 359         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 360                         LTTNG_KERNEL_SESSION_START);
 361 }
 362
 363 int kernctl_stop_session(int fd)
 364 {
 365         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 366                         LTTNG_KERNEL_SESSION_STOP);
 367 }
 368
 369 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter)
 370 {
 371         struct lttng_kernel_filter_bytecode *kb;
 372         uint32_t len;
 373         int ret;
 374
 375         /* Translate bytecode to kernel bytecode */
 376         kb = zmalloc(sizeof(*kb) + filter->len);
 377         if (!kb)
 378                 return -ENOMEM;
 379         kb->len = len = filter->len;
 380         kb->reloc_offset = filter->reloc_table_offset;
 381         kb->seqnum = filter->seqnum;
 382         memcpy(kb->data, filter->data, len);
 383         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_FILTER, kb);
 384         free(kb);
 385         return ret;
 386 }
 387
 388 int kernctl_add_callsite(int fd, struct lttng_kernel_event_callsite *callsite)
 389 {
 390         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_ADD_CALLSITE, callsite);
 391 }
 392
 393 int kernctl_tracepoint_list(int fd)
 394 {
 395         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 396                         LTTNG_KERNEL_TRACEPOINT_LIST);
 397 }
 398
 399 int kernctl_syscall_list(int fd)
 400 {
 401         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_SYSCALL_LIST);
 402 }
 403
 404 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 405 {
 406         int ret;
 407
 408         if (lttng_kernel_use_old_abi == -1) {
 409                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 410                 if (!ret) {
 411                         lttng_kernel_use_old_abi = 0;
 412                         goto end;
 413                 }
 414                 lttng_kernel_use_old_abi = 1;
 415         }
 416         if (lttng_kernel_use_old_abi) {
 417                 struct lttng_kernel_old_tracer_version old_v;
 418
 419                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 420                 if (ret) {
 421                         goto end;
 422                 }
 423                 v->major = old_v.major;
 424                 v->minor = old_v.minor;
 425                 v->patchlevel = old_v.patchlevel;
 426         } else {
 427                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 428         }
 429
 430 end:
 431         return ret;
 432 }
 433
 434 int kernctl_tracer_abi_version(int fd,
 435                 struct lttng_kernel_tracer_abi_version *v)
 436 {
 437         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 438 }
 439
 440 int kernctl_wait_quiescent(int fd)
 441 {
 442         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 443                         LTTNG_KERNEL_WAIT_QUIESCENT);
 444 }
 445
 446 int kernctl_buffer_flush(int fd)
 447 {
 448         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_FLUSH);
 449 }
 450
 451 int kernctl_buffer_flush_empty(int fd)
 452 {
 453         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_FLUSH_EMPTY);
 454 }
 455
 456 /* returns the version of the metadata. */
 457 int kernctl_get_metadata_version(int fd, uint64_t *version)
 458 {
 459         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_METADATA_VERSION, version);
 460 }
 461
 462 int kernctl_metadata_cache_dump(int fd)
 463 {
 464         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_METADATA_CACHE_DUMP);
 465 }
 466
 467 /* Buffer operations */
 468
 469 /* For mmap mode, readable without "get" operation */
 470
 471 /* returns the length to mmap. */
 472 int kernctl_get_mmap_len(int fd, unsigned long *len)
 473 {
 474         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MMAP_LEN, len);
 475 }
 476
 477 /* returns the maximum size for sub-buffers. */
 478 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 479 {
 480         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 481 }
 482
 483 /*
 484  * For mmap mode, operate on the current packet (between get/put or
 485  * get_next/put_next).
 486  */
 487
 488 /* returns the offset of the subbuffer belonging to the mmap reader. */
 489 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 490 {
 491         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 492 }
 493
 494 /* returns the size of the current sub-buffer, without padding (for mmap). */
 495 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 496 {
 497         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 498 }
 499
 500 /* returns the size of the current sub-buffer, without padding (for mmap). */
 501 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 502 {
 503         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 504 }
 505
 506 /* Get exclusive read access to the next sub-buffer that can be read. */
 507 int kernctl_get_next_subbuf(int fd)
 508 {
 509         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 510 }
 511
 512
 513 /* Release exclusive sub-buffer access, move consumer forward. */
 514 int kernctl_put_next_subbuf(int fd)
 515 {
 516         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 517 }
 518
 519 /* snapshot */
 520
 521 /* Get a snapshot of the current ring buffer producer and consumer positions */
 522 int kernctl_snapshot(int fd)
 523 {
 524         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT);
 525 }
 526
 527 /*
 528  * Get a snapshot of the current ring buffer producer and consumer positions,
 529  * regardless of whether or not the two positions are contained within the
 530  * same sub-buffer.
 531  */
 532 int kernctl_snapshot_sample_positions(int fd)
 533 {
 534         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS);
 535 }
 536
 537 /* Get the consumer position (iteration start) */
 538 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 539 {
 540         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 541 }
 542
 543 /* Get the producer position (iteration end) */
 544 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 545 {
 546         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 547 }
 548
 549 /* Get exclusive read access to the specified sub-buffer position */
 550 int kernctl_get_subbuf(int fd, unsigned long *len)
 551 {
 552         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_SUBBUF, len);
 553 }
 554
 555 /* Release exclusive sub-buffer access */
 556 int kernctl_put_subbuf(int fd)
 557 {
 558         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_PUT_SUBBUF);
 559 }
 560
 561 /* Returns the timestamp begin of the current sub-buffer. */
 562 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 563 {
 564         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN,
 565                         timestamp_begin);
 566 }
 567
 568 /* Returns the timestamp end of the current sub-buffer. */
 569 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 570 {
 571         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END,
 572                         timestamp_end);
 573 }
 574
 575 /* Returns the number of discarded events in the current sub-buffer. */
 576 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 577 {
 578         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED,
 579                         events_discarded);
 580 }
 581
 582 /* Returns the content size in the current sub-buffer. */
 583 int kernctl_get_content_size(int fd, uint64_t *content_size)
 584 {
 585         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE,
 586                         content_size);
 587 }
 588
 589 /* Returns the packet size in the current sub-buffer. */
 590 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 591 {
 592         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE,
 593                         packet_size);
 594 }
 595
 596 /* Returns the stream id of the current sub-buffer. */
 597 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 598 {
 599         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_STREAM_ID,
 600                         stream_id);
 601 }
 602
 603 /* Returns the current timestamp. */
 604 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 605 {
 606         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP,
 607                         ts);
 608 }
 609
 610 /* Returns the packet sequence number of the current sub-buffer. */
 611 int kernctl_get_sequence_number(int fd, uint64_t *seq)
 612 {
 613         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_SEQ_NUM, seq);
 614 }
 615
 616 /* Returns the stream instance id. */
 617 int kernctl_get_instance_id(int fd, uint64_t *id)
 618 {
 619         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_INSTANCE_ID, id);
 620 }