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

   1 /*
   2  * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
   3  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-only
   7  *
   8  */
   9
  10 #include "lttng/tracker.h"
  11 #define _LGPL_SOURCE
  12 #define __USE_LINUX_IOCTL_DEFS
  13 #include <sys/ioctl.h>
  14 #include <string.h>
  15 #include <common/align.h>
  16 #include <common/macros.h>
  17 #include <errno.h>
  18 #include <stdarg.h>
  19 #include <assert.h>
  20 #include <common/time.h>
  21
  22 #include "kernel-ctl.h"
  23 #include "kernel-ioctl.h"
  24
  25 #define LTTNG_IOCTL_CHECK(fildes, request, ...) ({      \
  26         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  27         assert(ret <= 0);                               \
  28         !ret ? 0 : -errno;                              \
  29 })
  30
  31 #define LTTNG_IOCTL_NO_CHECK(fildes, request, ...) ({   \
  32         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  33         ret >= 0 ? ret : -errno;                        \
  34 })
  35
  36 /*
  37  * This flag indicates which version of the kernel ABI to use. The old
  38  * ABI (namespace _old) does not support a 32-bit user-space when the
  39  * kernel is 64-bit. The old ABI is kept here for compatibility but is
  40  * deprecated and will be removed eventually.
  41  */
  42 static int lttng_kernel_use_old_abi = -1;
  43
  44 /*
  45  * Execute the new or old ioctl depending on the ABI version.
  46  * If the ABI version is not determined yet (lttng_kernel_use_old_abi = -1),
  47  * this function tests if the new ABI is available and otherwise fallbacks
  48  * on the old one.
  49  * This function takes the fd on which the ioctl must be executed and the old
  50  * and new request codes.
  51  * It returns the return value of the ioctl executed.
  52  */
  53 static inline int compat_ioctl_no_arg(int fd, unsigned long oldname,
  54                 unsigned long newname)
  55 {
  56         int ret;
  57
  58         if (lttng_kernel_use_old_abi == -1) {
  59                 ret = LTTNG_IOCTL_NO_CHECK(fd, newname);
  60                 if (!ret) {
  61                         lttng_kernel_use_old_abi = 0;
  62                         goto end;
  63                 }
  64                 lttng_kernel_use_old_abi = 1;
  65         }
  66         if (lttng_kernel_use_old_abi) {
  67                 ret = LTTNG_IOCTL_NO_CHECK(fd, oldname);
  68         } else {
  69                 ret = LTTNG_IOCTL_NO_CHECK(fd, newname);
  70         }
  71
  72 end:
  73         return ret;
  74 }
  75
  76 int kernctl_create_session(int fd)
  77 {
  78         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION,
  79                         LTTNG_KERNEL_SESSION);
  80 }
  81
  82 /* open the metadata global channel */
  83 int kernctl_open_metadata(int fd, struct lttng_channel_attr *chops)
  84 {
  85         struct lttng_kernel_channel channel;
  86
  87         if (lttng_kernel_use_old_abi) {
  88                 struct lttng_kernel_old_channel old_channel;
  89
  90                 memset(&old_channel, 0, sizeof(old_channel));
  91                 old_channel.overwrite = chops->overwrite;
  92                 old_channel.subbuf_size = chops->subbuf_size;
  93                 old_channel.num_subbuf = chops->num_subbuf;
  94                 old_channel.switch_timer_interval = chops->switch_timer_interval;
  95                 old_channel.read_timer_interval = chops->read_timer_interval;
  96                 old_channel.output = chops->output;
  97
  98                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
  99                 /*
 100                  * The new channel padding is smaller than the old ABI so we use the
 101                  * new ABI padding size for the memcpy.
 102                  */
 103                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 104
 105                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_METADATA,
 106                                 &old_channel);
 107         }
 108
 109         memset(&channel, 0, sizeof(channel));
 110         channel.overwrite = chops->overwrite;
 111         channel.subbuf_size = chops->subbuf_size;
 112         channel.num_subbuf = chops->num_subbuf;
 113         channel.switch_timer_interval = chops->switch_timer_interval;
 114         channel.read_timer_interval = chops->read_timer_interval;
 115         channel.output = chops->output;
 116         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 117
 118         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_METADATA, &channel);
 119 }
 120
 121 int kernctl_create_channel(int fd, struct lttng_channel_attr *chops)
 122 {
 123         struct lttng_kernel_channel channel;
 124
 125         memset(&channel, 0, sizeof(channel));
 126         if (lttng_kernel_use_old_abi) {
 127                 struct lttng_kernel_old_channel old_channel;
 128
 129                 old_channel.overwrite = chops->overwrite;
 130                 old_channel.subbuf_size = chops->subbuf_size;
 131                 old_channel.num_subbuf = chops->num_subbuf;
 132                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 133                 old_channel.read_timer_interval = chops->read_timer_interval;
 134                 old_channel.output = chops->output;
 135
 136                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 137                 /*
 138                  * The new channel padding is smaller than the old ABI so we use the
 139                  * new ABI padding size for the memcpy.
 140                  */
 141                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 142
 143                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_CHANNEL,
 144                                 &old_channel);
 145         }
 146
 147         channel.overwrite = chops->overwrite;
 148         channel.subbuf_size = chops->subbuf_size;
 149         channel.num_subbuf = chops->num_subbuf;
 150         channel.switch_timer_interval = chops->switch_timer_interval;
 151         channel.read_timer_interval = chops->read_timer_interval;
 152         channel.output = chops->output;
 153         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 154
 155         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_CHANNEL, &channel);
 156 }
 157
 158 int kernctl_syscall_mask(int fd, char **syscall_mask, uint32_t *nr_bits)
 159 {
 160         struct lttng_kernel_syscall_mask kmask_len, *kmask = NULL;
 161         size_t array_alloc_len;
 162         char *new_mask;
 163         int ret = 0;
 164
 165         if (!syscall_mask) {
 166                 ret = -1;
 167                 goto end;
 168         }
 169
 170         if (!nr_bits) {
 171                 ret = -1;
 172                 goto end;
 173         }
 174
 175         kmask_len.len = 0;
 176         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SYSCALL_MASK, &kmask_len);
 177         if (ret) {
 178                 goto end;
 179         }
 180
 181         array_alloc_len = ALIGN(kmask_len.len, 8) >> 3;
 182
 183         kmask = zmalloc(sizeof(*kmask) + array_alloc_len);
 184         if (!kmask) {
 185                 ret = -1;
 186                 goto end;
 187         }
 188
 189         kmask->len = kmask_len.len;
 190         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SYSCALL_MASK, kmask);
 191         if (ret) {
 192                 goto end;
 193         }
 194
 195         new_mask = realloc(*syscall_mask, array_alloc_len);
 196         if (!new_mask) {
 197                 ret = -1;
 198                 goto end;
 199         }
 200         memcpy(new_mask, kmask->mask, array_alloc_len);
 201         *syscall_mask = new_mask;
 202         *nr_bits = kmask->len;
 203
 204 end:
 205         free(kmask);
 206         return ret;
 207 }
 208
 209 int kernctl_track_pid(int fd, int pid)
 210 {
 211         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_TRACK_PID, pid);
 212 }
 213
 214 int kernctl_untrack_pid(int fd, int pid)
 215 {
 216         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_UNTRACK_PID, pid);
 217 }
 218
 219 int kernctl_list_tracker_pids(int fd)
 220 {
 221         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS);
 222 }
 223
 224 static enum lttng_kernel_tracker_type get_kernel_tracker_type(
 225                 enum lttng_process_attr process_attr)
 226 {
 227         switch (process_attr) {
 228         case LTTNG_PROCESS_ATTR_PROCESS_ID:
 229                 return LTTNG_KERNEL_TRACKER_PID;
 230         case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
 231                 return LTTNG_KERNEL_TRACKER_VPID;
 232         case LTTNG_PROCESS_ATTR_USER_ID:
 233                 return LTTNG_KERNEL_TRACKER_UID;
 234         case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
 235                 return LTTNG_KERNEL_TRACKER_VUID;
 236         case LTTNG_PROCESS_ATTR_GROUP_ID:
 237                 return LTTNG_KERNEL_TRACKER_GID;
 238         case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
 239                 return LTTNG_KERNEL_TRACKER_VGID;
 240         default:
 241                 return LTTNG_KERNEL_TRACKER_UNKNOWN;
 242         }
 243 }
 244
 245 int kernctl_track_id(int fd, enum lttng_process_attr process_attr, int id)
 246 {
 247         struct lttng_kernel_tracker_args args;
 248
 249         args.id = id;
 250         args.type = get_kernel_tracker_type(process_attr);
 251         if (args.type == LTTNG_KERNEL_TRACKER_UNKNOWN) {
 252                 errno = EINVAL;
 253                 return -1;
 254         }
 255         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_TRACK_ID, &args);
 256 }
 257
 258 int kernctl_untrack_id(int fd, enum lttng_process_attr process_attr, int id)
 259 {
 260         struct lttng_kernel_tracker_args args;
 261
 262         args.id = id;
 263         args.type = get_kernel_tracker_type(process_attr);
 264         if (args.type == LTTNG_KERNEL_TRACKER_UNKNOWN) {
 265                 errno = EINVAL;
 266                 return -1;
 267         }
 268         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_UNTRACK_ID, &args);
 269 }
 270
 271 int kernctl_list_tracker_ids(int fd, enum lttng_process_attr process_attr)
 272 {
 273         struct lttng_kernel_tracker_args args;
 274
 275         args.id = -1;
 276         args.type = get_kernel_tracker_type(process_attr);
 277         if (args.type == LTTNG_KERNEL_TRACKER_UNKNOWN) {
 278                 errno = EINVAL;
 279                 return -1;
 280         }
 281         return LTTNG_IOCTL_NO_CHECK(
 282                         fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_IDS, &args);
 283 }
 284
 285 int kernctl_session_regenerate_metadata(int fd)
 286 {
 287         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_METADATA_REGEN);
 288 }
 289
 290 int kernctl_session_regenerate_statedump(int fd)
 291 {
 292         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_STATEDUMP);
 293 }
 294
 295 int kernctl_session_set_name(int fd, const char *name)
 296 {
 297         int ret;
 298         struct lttng_kernel_session_name session_name;
 299
 300         ret = lttng_strncpy(session_name.name, name, sizeof(session_name.name));
 301         if (ret) {
 302                 goto end;
 303         }
 304
 305         ret = LTTNG_IOCTL_CHECK(
 306                         fd, LTTNG_KERNEL_SESSION_SET_NAME, &session_name);
 307 end:
 308         return ret;
 309 }
 310
 311 int kernctl_session_set_creation_time(int fd, time_t time)
 312 {
 313         int ret;
 314         struct lttng_kernel_session_creation_time creation_time;
 315
 316         ret = time_to_iso8601_str(time, creation_time.iso8601,
 317                         sizeof(creation_time.iso8601));
 318         if (ret) {
 319                 goto end;
 320         }
 321
 322         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_SESSION_SET_CREATION_TIME,
 323                         &creation_time);
 324 end:
 325         return ret;
 326 }
 327
 328 int kernctl_create_stream(int fd)
 329 {
 330         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 331                         LTTNG_KERNEL_STREAM);
 332 }
 333
 334 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 335 {
 336         if (lttng_kernel_use_old_abi) {
 337                 struct lttng_kernel_old_event old_event;
 338
 339                 memset(&old_event, 0, sizeof(old_event));
 340                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 341                 old_event.instrumentation = ev->instrumentation;
 342                 switch (ev->instrumentation) {
 343                 case LTTNG_KERNEL_KPROBE:
 344                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 345                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 346                         memcpy(old_event.u.kprobe.symbol_name,
 347                                 ev->u.kprobe.symbol_name,
 348                                 sizeof(old_event.u.kprobe.symbol_name));
 349                         break;
 350                 case LTTNG_KERNEL_KRETPROBE:
 351                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 352                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 353                         memcpy(old_event.u.kretprobe.symbol_name,
 354                                 ev->u.kretprobe.symbol_name,
 355                                 sizeof(old_event.u.kretprobe.symbol_name));
 356                         break;
 357                 case LTTNG_KERNEL_FUNCTION:
 358                         memcpy(old_event.u.ftrace.symbol_name,
 359                                         ev->u.ftrace.symbol_name,
 360                                         sizeof(old_event.u.ftrace.symbol_name));
 361                         break;
 362                 default:
 363                         break;
 364                 }
 365
 366                 return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_OLD_EVENT,
 367                                 &old_event);
 368         }
 369         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_EVENT, ev);
 370 }
 371
 372 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 373 {
 374         if (lttng_kernel_use_old_abi) {
 375                 struct lttng_kernel_old_context old_ctx;
 376
 377                 memset(&old_ctx, 0, sizeof(old_ctx));
 378                 old_ctx.ctx = ctx->ctx;
 379                 /* only type that uses the union */
 380                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 381                         old_ctx.u.perf_counter.type =
 382                                 ctx->u.perf_counter.type;
 383                         old_ctx.u.perf_counter.config =
 384                                 ctx->u.perf_counter.config;
 385                         memcpy(old_ctx.u.perf_counter.name,
 386                                 ctx->u.perf_counter.name,
 387                                 sizeof(old_ctx.u.perf_counter.name));
 388                 }
 389                 return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 390         }
 391         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_CONTEXT, ctx);
 392 }
 393
 394
 395 /* Enable event, channel and session LTTNG_IOCTL_CHECK */
 396 int kernctl_enable(int fd)
 397 {
 398         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 399                         LTTNG_KERNEL_ENABLE);
 400 }
 401
 402 /* Disable event, channel and session LTTNG_IOCTL_CHECK */
 403 int kernctl_disable(int fd)
 404 {
 405         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 406                         LTTNG_KERNEL_DISABLE);
 407 }
 408
 409 int kernctl_start_session(int fd)
 410 {
 411         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 412                         LTTNG_KERNEL_SESSION_START);
 413 }
 414
 415 int kernctl_stop_session(int fd)
 416 {
 417         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 418                         LTTNG_KERNEL_SESSION_STOP);
 419 }
 420
 421 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter)
 422 {
 423         struct lttng_kernel_filter_bytecode *kb;
 424         uint32_t len;
 425         int ret;
 426
 427         /* Translate bytecode to kernel bytecode */
 428         kb = zmalloc(sizeof(*kb) + filter->len);
 429         if (!kb)
 430                 return -ENOMEM;
 431         kb->len = len = filter->len;
 432         kb->reloc_offset = filter->reloc_table_offset;
 433         kb->seqnum = filter->seqnum;
 434         memcpy(kb->data, filter->data, len);
 435         ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_FILTER, kb);
 436         free(kb);
 437         return ret;
 438 }
 439
 440 int kernctl_add_callsite(int fd, struct lttng_kernel_event_callsite *callsite)
 441 {
 442         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_ADD_CALLSITE, callsite);
 443 }
 444
 445 int kernctl_tracepoint_list(int fd)
 446 {
 447         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 448                         LTTNG_KERNEL_TRACEPOINT_LIST);
 449 }
 450
 451 int kernctl_syscall_list(int fd)
 452 {
 453         return LTTNG_IOCTL_NO_CHECK(fd, LTTNG_KERNEL_SYSCALL_LIST);
 454 }
 455
 456 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 457 {
 458         int ret;
 459
 460         if (lttng_kernel_use_old_abi == -1) {
 461                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 462                 if (!ret) {
 463                         lttng_kernel_use_old_abi = 0;
 464                         goto end;
 465                 }
 466                 lttng_kernel_use_old_abi = 1;
 467         }
 468         if (lttng_kernel_use_old_abi) {
 469                 struct lttng_kernel_old_tracer_version old_v;
 470
 471                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 472                 if (ret) {
 473                         goto end;
 474                 }
 475                 v->major = old_v.major;
 476                 v->minor = old_v.minor;
 477                 v->patchlevel = old_v.patchlevel;
 478         } else {
 479                 ret = LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 480         }
 481
 482 end:
 483         return ret;
 484 }
 485
 486 int kernctl_tracer_abi_version(int fd,
 487                 struct lttng_kernel_tracer_abi_version *v)
 488 {
 489         return LTTNG_IOCTL_CHECK(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 490 }
 491
 492 int kernctl_wait_quiescent(int fd)
 493 {
 494         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 495                         LTTNG_KERNEL_WAIT_QUIESCENT);
 496 }
 497
 498 int kernctl_buffer_flush(int fd)
 499 {
 500         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_FLUSH);
 501 }
 502
 503 int kernctl_buffer_flush_empty(int fd)
 504 {
 505         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_FLUSH_EMPTY);
 506 }
 507
 508 int kernctl_buffer_clear(int fd)
 509 {
 510         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_CLEAR);
 511 }
 512
 513 int kernctl_get_next_subbuf_metadata_check(int fd, bool *consistent)
 514 {
 515         return LTTNG_IOCTL_NO_CHECK(fd,
 516                         RING_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK,
 517                         consistent);
 518 }
 519
 520 /* returns the version of the metadata. */
 521 int kernctl_get_metadata_version(int fd, uint64_t *version)
 522 {
 523         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_METADATA_VERSION, version);
 524 }
 525
 526 int kernctl_metadata_cache_dump(int fd)
 527 {
 528         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_METADATA_CACHE_DUMP);
 529 }
 530
 531 /* Buffer operations */
 532
 533 /* For mmap mode, readable without "get" operation */
 534
 535 /* returns the length to mmap. */
 536 int kernctl_get_mmap_len(int fd, unsigned long *len)
 537 {
 538         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MMAP_LEN, len);
 539 }
 540
 541 /* returns the maximum size for sub-buffers. */
 542 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 543 {
 544         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 545 }
 546
 547 /*
 548  * For mmap mode, operate on the current packet (between get/put or
 549  * get_next/put_next).
 550  */
 551
 552 /* returns the offset of the subbuffer belonging to the mmap reader. */
 553 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 554 {
 555         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 556 }
 557
 558 /* returns the size of the current sub-buffer, without padding (for mmap). */
 559 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 560 {
 561         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 562 }
 563
 564 /* returns the size of the current sub-buffer, without padding (for mmap). */
 565 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 566 {
 567         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 568 }
 569
 570 /* Get exclusive read access to the next sub-buffer that can be read. */
 571 int kernctl_get_next_subbuf(int fd)
 572 {
 573         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 574 }
 575
 576
 577 /* Release exclusive sub-buffer access, move consumer forward. */
 578 int kernctl_put_next_subbuf(int fd)
 579 {
 580         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 581 }
 582
 583 /* snapshot */
 584
 585 /* Get a snapshot of the current ring buffer producer and consumer positions */
 586 int kernctl_snapshot(int fd)
 587 {
 588         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT);
 589 }
 590
 591 /*
 592  * Get a snapshot of the current ring buffer producer and consumer positions,
 593  * regardless of whether or not the two positions are contained within the
 594  * same sub-buffer.
 595  */
 596 int kernctl_snapshot_sample_positions(int fd)
 597 {
 598         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS);
 599 }
 600
 601 /* Get the consumer position (iteration start) */
 602 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 603 {
 604         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 605 }
 606
 607 /* Get the producer position (iteration end) */
 608 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 609 {
 610         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 611 }
 612
 613 /* Get exclusive read access to the specified sub-buffer position */
 614 int kernctl_get_subbuf(int fd, unsigned long *len)
 615 {
 616         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_GET_SUBBUF, len);
 617 }
 618
 619 /* Release exclusive sub-buffer access */
 620 int kernctl_put_subbuf(int fd)
 621 {
 622         return LTTNG_IOCTL_CHECK(fd, RING_BUFFER_PUT_SUBBUF);
 623 }
 624
 625 /* Returns the timestamp begin of the current sub-buffer. */
 626 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 627 {
 628         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN,
 629                         timestamp_begin);
 630 }
 631
 632 /* Returns the timestamp end of the current sub-buffer. */
 633 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 634 {
 635         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END,
 636                         timestamp_end);
 637 }
 638
 639 /* Returns the number of discarded events in the current sub-buffer. */
 640 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 641 {
 642         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED,
 643                         events_discarded);
 644 }
 645
 646 /* Returns the content size in the current sub-buffer. */
 647 int kernctl_get_content_size(int fd, uint64_t *content_size)
 648 {
 649         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE,
 650                         content_size);
 651 }
 652
 653 /* Returns the packet size in the current sub-buffer. */
 654 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 655 {
 656         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE,
 657                         packet_size);
 658 }
 659
 660 /* Returns the stream id of the current sub-buffer. */
 661 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 662 {
 663         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_STREAM_ID,
 664                         stream_id);
 665 }
 666
 667 /* Returns the current timestamp. */
 668 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 669 {
 670         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP,
 671                         ts);
 672 }
 673
 674 /* Returns the packet sequence number of the current sub-buffer. */
 675 int kernctl_get_sequence_number(int fd, uint64_t *seq)
 676 {
 677         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_GET_SEQ_NUM, seq);
 678 }
 679
 680 /* Returns the stream instance id. */
 681 int kernctl_get_instance_id(int fd, uint64_t *id)
 682 {
 683         return LTTNG_IOCTL_CHECK(fd, LTTNG_RING_BUFFER_INSTANCE_ID, id);
 684 }