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