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