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(fildes, request, ...) ({            \
  33         int ret = ioctl(fildes, request, ##__VA_ARGS__);\
  34         assert(ret <= 0);                               \
  35         ret ? -errno : 0;                               \
  36 })
  37
  38 /*
  39  * This flag indicates which version of the kernel ABI to use. The old
  40  * ABI (namespace _old) does not support a 32-bit user-space when the
  41  * kernel is 64-bit. The old ABI is kept here for compatibility but is
  42  * deprecated and will be removed eventually.
  43  */
  44 static int lttng_kernel_use_old_abi = -1;
  45
  46 /*
  47  * Execute the new or old ioctl depending on the ABI version.
  48  * If the ABI version is not determined yet (lttng_kernel_use_old_abi = -1),
  49  * this function tests if the new ABI is available and otherwise fallbacks
  50  * on the old one.
  51  * This function takes the fd on which the ioctl must be executed and the old
  52  * and new request codes.
  53  * It returns the return value of the ioctl executed.
  54  */
  55 static inline int compat_ioctl_no_arg(int fd, unsigned long oldname,
  56                 unsigned long newname)
  57 {
  58         int ret;
  59
  60         if (lttng_kernel_use_old_abi == -1) {
  61                 ret = ioctl(fd, newname);
  62                 if (!ret) {
  63                         lttng_kernel_use_old_abi = 0;
  64                         goto end;
  65                 }
  66                 lttng_kernel_use_old_abi = 1;
  67         }
  68         if (lttng_kernel_use_old_abi) {
  69                 ret = ioctl(fd, oldname);
  70         } else {
  71                 ret = ioctl(fd, newname);
  72         }
  73
  74 end:
  75         return ret;
  76 }
  77
  78 int kernctl_create_session(int fd)
  79 {
  80         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION,
  81                         LTTNG_KERNEL_SESSION);
  82 }
  83
  84 /* open the metadata global channel */
  85 int kernctl_open_metadata(int fd, struct lttng_channel_attr *chops)
  86 {
  87         struct lttng_kernel_old_channel old_channel;
  88         struct lttng_kernel_channel channel;
  89
  90         if (lttng_kernel_use_old_abi) {
  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 ioctl(fd, LTTNG_KERNEL_OLD_METADATA, &old_channel);
 106         }
 107
 108         channel.overwrite = chops->overwrite;
 109         channel.subbuf_size = chops->subbuf_size;
 110         channel.num_subbuf = chops->num_subbuf;
 111         channel.switch_timer_interval = chops->switch_timer_interval;
 112         channel.read_timer_interval = chops->read_timer_interval;
 113         channel.output = chops->output;
 114         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 115
 116         return ioctl(fd, LTTNG_KERNEL_METADATA, &channel);
 117 }
 118
 119 int kernctl_create_channel(int fd, struct lttng_channel_attr *chops)
 120 {
 121         struct lttng_kernel_channel channel;
 122
 123         memset(&channel, 0, sizeof(channel));
 124         if (lttng_kernel_use_old_abi) {
 125                 struct lttng_kernel_old_channel old_channel;
 126
 127                 old_channel.overwrite = chops->overwrite;
 128                 old_channel.subbuf_size = chops->subbuf_size;
 129                 old_channel.num_subbuf = chops->num_subbuf;
 130                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 131                 old_channel.read_timer_interval = chops->read_timer_interval;
 132                 old_channel.output = chops->output;
 133
 134                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 135                 /*
 136                  * The new channel padding is smaller than the old ABI so we use the
 137                  * new ABI padding size for the memcpy.
 138                  */
 139                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 140
 141                 return ioctl(fd, LTTNG_KERNEL_OLD_CHANNEL, &old_channel);
 142         }
 143
 144         channel.overwrite = chops->overwrite;
 145         channel.subbuf_size = chops->subbuf_size;
 146         channel.num_subbuf = chops->num_subbuf;
 147         channel.switch_timer_interval = chops->switch_timer_interval;
 148         channel.read_timer_interval = chops->read_timer_interval;
 149         channel.output = chops->output;
 150         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 151
 152         return ioctl(fd, LTTNG_KERNEL_CHANNEL, &channel);
 153 }
 154
 155 int kernctl_syscall_mask(int fd, char **syscall_mask, uint32_t *nr_bits)
 156 {
 157         struct lttng_kernel_syscall_mask kmask_len, *kmask = NULL;
 158         size_t array_alloc_len;
 159         char *new_mask;
 160         int ret = 0;
 161
 162         if (!syscall_mask) {
 163                 ret = -1;
 164                 goto end;
 165         }
 166
 167         if (!nr_bits) {
 168                 ret = -1;
 169                 goto end;
 170         }
 171
 172         kmask_len.len = 0;
 173         ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_SYSCALL_MASK, &kmask_len);
 174         if (ret) {
 175                 goto end;
 176         }
 177
 178         array_alloc_len = ALIGN(kmask_len.len, 8) >> 3;
 179
 180         kmask = zmalloc(sizeof(*kmask) + array_alloc_len);
 181         if (!kmask) {
 182                 ret = -1;
 183                 goto end;
 184         }
 185
 186         kmask->len = kmask_len.len;
 187         ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_SYSCALL_MASK, kmask);
 188         if (ret) {
 189                 goto end;
 190         }
 191
 192         new_mask = realloc(*syscall_mask, array_alloc_len);
 193         if (!new_mask) {
 194                 ret = -1;
 195                 goto end;
 196         }
 197         memcpy(new_mask, kmask->mask, array_alloc_len);
 198         *syscall_mask = new_mask;
 199         *nr_bits = kmask->len;
 200
 201 end:
 202         free(kmask);
 203         return ret;
 204 }
 205
 206 int kernctl_track_pid(int fd, int pid)
 207 {
 208         return LTTNG_IOCTL(fd, LTTNG_KERNEL_SESSION_TRACK_PID, pid);
 209 }
 210
 211 int kernctl_untrack_pid(int fd, int pid)
 212 {
 213         return LTTNG_IOCTL(fd, LTTNG_KERNEL_SESSION_UNTRACK_PID, pid);
 214 }
 215
 216 int kernctl_list_tracker_pids(int fd)
 217 {
 218         return ioctl(fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS);
 219 }
 220
 221 int kernctl_session_metadata_regenerate(int fd)
 222 {
 223         return LTTNG_IOCTL(fd, LTTNG_KERNEL_SESSION_METADATA_REGEN);
 224 }
 225
 226 int kernctl_create_stream(int fd)
 227 {
 228         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 229                         LTTNG_KERNEL_STREAM);
 230 }
 231
 232 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 233 {
 234         if (lttng_kernel_use_old_abi) {
 235                 struct lttng_kernel_old_event old_event;
 236
 237                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 238                 old_event.instrumentation = ev->instrumentation;
 239                 switch (ev->instrumentation) {
 240                 case LTTNG_KERNEL_KPROBE:
 241                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 242                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 243                         memcpy(old_event.u.kprobe.symbol_name,
 244                                 ev->u.kprobe.symbol_name,
 245                                 sizeof(old_event.u.kprobe.symbol_name));
 246                         break;
 247                 case LTTNG_KERNEL_KRETPROBE:
 248                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 249                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 250                         memcpy(old_event.u.kretprobe.symbol_name,
 251                                 ev->u.kretprobe.symbol_name,
 252                                 sizeof(old_event.u.kretprobe.symbol_name));
 253                         break;
 254                 case LTTNG_KERNEL_FUNCTION:
 255                         memcpy(old_event.u.ftrace.symbol_name,
 256                                         ev->u.ftrace.symbol_name,
 257                                         sizeof(old_event.u.ftrace.symbol_name));
 258                         break;
 259                 default:
 260                         break;
 261                 }
 262
 263                 return ioctl(fd, LTTNG_KERNEL_OLD_EVENT, &old_event);
 264         }
 265         return ioctl(fd, LTTNG_KERNEL_EVENT, ev);
 266 }
 267
 268 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 269 {
 270         if (lttng_kernel_use_old_abi) {
 271                 struct lttng_kernel_old_context old_ctx;
 272
 273                 old_ctx.ctx = ctx->ctx;
 274                 /* only type that uses the union */
 275                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 276                         old_ctx.u.perf_counter.type =
 277                                 ctx->u.perf_counter.type;
 278                         old_ctx.u.perf_counter.config =
 279                                 ctx->u.perf_counter.config;
 280                         memcpy(old_ctx.u.perf_counter.name,
 281                                 ctx->u.perf_counter.name,
 282                                 sizeof(old_ctx.u.perf_counter.name));
 283                 }
 284                 return LTTNG_IOCTL(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 285         }
 286         return LTTNG_IOCTL(fd, LTTNG_KERNEL_CONTEXT, ctx);
 287 }
 288
 289
 290 /* Enable event, channel and session LTTNG_IOCTL */
 291 int kernctl_enable(int fd)
 292 {
 293         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 294                         LTTNG_KERNEL_ENABLE);
 295 }
 296
 297 /* Disable event, channel and session LTTNG_IOCTL */
 298 int kernctl_disable(int fd)
 299 {
 300         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 301                         LTTNG_KERNEL_DISABLE);
 302 }
 303
 304 int kernctl_start_session(int fd)
 305 {
 306         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 307                         LTTNG_KERNEL_SESSION_START);
 308 }
 309
 310 int kernctl_stop_session(int fd)
 311 {
 312         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 313                         LTTNG_KERNEL_SESSION_STOP);
 314 }
 315
 316 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter)
 317 {
 318         struct lttng_kernel_filter_bytecode *kb;
 319         uint32_t len;
 320         int ret;
 321
 322         /* Translate bytecode to kernel bytecode */
 323         kb = zmalloc(sizeof(*kb) + filter->len);
 324         if (!kb)
 325                 return -ENOMEM;
 326         kb->len = len = filter->len;
 327         kb->reloc_offset = filter->reloc_table_offset;
 328         kb->seqnum = filter->seqnum;
 329         memcpy(kb->data, filter->data, len);
 330         ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_FILTER, kb);
 331         free(kb);
 332         return ret;
 333 }
 334
 335 int kernctl_tracepoint_list(int fd)
 336 {
 337         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 338                         LTTNG_KERNEL_TRACEPOINT_LIST);
 339 }
 340
 341 int kernctl_syscall_list(int fd)
 342 {
 343         return ioctl(fd, LTTNG_KERNEL_SYSCALL_LIST);
 344 }
 345
 346 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 347 {
 348         int ret;
 349
 350         if (lttng_kernel_use_old_abi == -1) {
 351                 ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 352                 if (!ret) {
 353                         lttng_kernel_use_old_abi = 0;
 354                         goto end;
 355                 }
 356                 lttng_kernel_use_old_abi = 1;
 357         }
 358         if (lttng_kernel_use_old_abi) {
 359                 struct lttng_kernel_old_tracer_version old_v;
 360
 361                 ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 362                 if (ret) {
 363                         goto end;
 364                 }
 365                 v->major = old_v.major;
 366                 v->minor = old_v.minor;
 367                 v->patchlevel = old_v.patchlevel;
 368         } else {
 369                 ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 370         }
 371
 372 end:
 373         return ret;
 374 }
 375
 376 int kernctl_tracer_abi_version(int fd,
 377                 struct lttng_kernel_tracer_abi_version *v)
 378 {
 379         return LTTNG_IOCTL(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 380 }
 381
 382 int kernctl_wait_quiescent(int fd)
 383 {
 384         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 385                         LTTNG_KERNEL_WAIT_QUIESCENT);
 386 }
 387
 388 int kernctl_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
 389 {
 390         int ret;
 391
 392         if (lttng_kernel_use_old_abi == -1) {
 393                 ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 394                 if (!ret) {
 395                         lttng_kernel_use_old_abi = 0;
 396                         goto end;
 397                 }
 398                 lttng_kernel_use_old_abi = 1;
 399         }
 400         if (lttng_kernel_use_old_abi) {
 401                 struct lttng_kernel_old_calibrate old_calibrate;
 402
 403                 old_calibrate.type = calibrate->type;
 404                 ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_OLD_CALIBRATE,
 405                                 &old_calibrate);
 406                 if (ret) {
 407                         goto end;
 408                 }
 409                 calibrate->type = old_calibrate.type;
 410         } else {
 411                 ret = LTTNG_IOCTL(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 412         }
 413
 414 end:
 415         return ret;
 416 }
 417
 418
 419 int kernctl_buffer_flush(int fd)
 420 {
 421         return LTTNG_IOCTL(fd, RING_BUFFER_FLUSH);
 422 }
 423
 424 /* returns the version of the metadata. */
 425 int kernctl_get_metadata_version(int fd, uint64_t *version)
 426 {
 427         return LTTNG_IOCTL(fd, RING_BUFFER_GET_METADATA_VERSION, version);
 428 }
 429
 430
 431 /* Buffer operations */
 432
 433 /* For mmap mode, readable without "get" operation */
 434
 435 /* returns the length to mmap. */
 436 int kernctl_get_mmap_len(int fd, unsigned long *len)
 437 {
 438         return LTTNG_IOCTL(fd, RING_BUFFER_GET_MMAP_LEN, len);
 439 }
 440
 441 /* returns the maximum size for sub-buffers. */
 442 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 443 {
 444         return LTTNG_IOCTL(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 445 }
 446
 447 /*
 448  * For mmap mode, operate on the current packet (between get/put or
 449  * get_next/put_next).
 450  */
 451
 452 /* returns the offset of the subbuffer belonging to the mmap reader. */
 453 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 454 {
 455         return LTTNG_IOCTL(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 456 }
 457
 458 /* returns the size of the current sub-buffer, without padding (for mmap). */
 459 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 460 {
 461         return LTTNG_IOCTL(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 462 }
 463
 464 /* returns the size of the current sub-buffer, without padding (for mmap). */
 465 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 466 {
 467         return LTTNG_IOCTL(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 468 }
 469
 470 /* Get exclusive read access to the next sub-buffer that can be read. */
 471 int kernctl_get_next_subbuf(int fd)
 472 {
 473         return LTTNG_IOCTL(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 474 }
 475
 476
 477 /* Release exclusive sub-buffer access, move consumer forward. */
 478 int kernctl_put_next_subbuf(int fd)
 479 {
 480         return LTTNG_IOCTL(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 481 }
 482
 483 /* snapshot */
 484
 485 /* Get a snapshot of the current ring buffer producer and consumer positions */
 486 int kernctl_snapshot(int fd)
 487 {
 488         return LTTNG_IOCTL(fd, RING_BUFFER_SNAPSHOT);
 489 }
 490
 491 /* Get the consumer position (iteration start) */
 492 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 493 {
 494         return LTTNG_IOCTL(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 495 }
 496
 497 /* Get the producer position (iteration end) */
 498 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 499 {
 500         return LTTNG_IOCTL(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 501 }
 502
 503 /* Get exclusive read access to the specified sub-buffer position */
 504 int kernctl_get_subbuf(int fd, unsigned long *len)
 505 {
 506         return LTTNG_IOCTL(fd, RING_BUFFER_GET_SUBBUF, len);
 507 }
 508
 509 /* Release exclusive sub-buffer access */
 510 int kernctl_put_subbuf(int fd)
 511 {
 512         return LTTNG_IOCTL(fd, RING_BUFFER_PUT_SUBBUF);
 513 }
 514
 515 /* Returns the timestamp begin of the current sub-buffer. */
 516 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 517 {
 518         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN,
 519                         timestamp_begin);
 520 }
 521
 522 /* Returns the timestamp end of the current sub-buffer. */
 523 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 524 {
 525         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END,
 526                         timestamp_end);
 527 }
 528
 529 /* Returns the number of discarded events in the current sub-buffer. */
 530 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 531 {
 532         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED,
 533                         events_discarded);
 534 }
 535
 536 /* Returns the content size in the current sub-buffer. */
 537 int kernctl_get_content_size(int fd, uint64_t *content_size)
 538 {
 539         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE,
 540                         content_size);
 541 }
 542
 543 /* Returns the packet size in the current sub-buffer. */
 544 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 545 {
 546         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE, packet_size);
 547 }
 548
 549 /* Returns the stream id of the current sub-buffer. */
 550 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 551 {
 552         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_STREAM_ID, stream_id);
 553 }
 554
 555 /* Returns the current timestamp. */
 556 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 557 {
 558         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP, ts);
 559 }
 560
 561 /* Returns the packet sequence number of the current sub-buffer. */
 562 int kernctl_get_sequence_number(int fd, uint64_t *seq)
 563 {
 564         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_GET_SEQ_NUM, seq);
 565 }
 566
 567 /* Returns the stream instance id. */
 568 int kernctl_get_instance_id(int fd, uint64_t *id)
 569 {
 570         return LTTNG_IOCTL(fd, LTTNG_RING_BUFFER_INSTANCE_ID, id);
 571 }