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 _LGPL_SOURCE
  20 #define __USE_LINUX_IOCTL_DEFS
  21 #include <sys/ioctl.h>
  22 #include <string.h>
  23 #include <common/align.h>
  24 #include <errno.h>
  25
  26 #include "kernel-ctl.h"
  27 #include "kernel-ioctl.h"
  28
  29 /*
  30  * This flag indicates which version of the kernel ABI to use. The old
  31  * ABI (namespace _old) does not support a 32-bit user-space when the
  32  * kernel is 64-bit. The old ABI is kept here for compatibility but is
  33  * deprecated and will be removed eventually.
  34  */
  35 static int lttng_kernel_use_old_abi = -1;
  36
  37 /*
  38  * Execute the new or old ioctl depending on the ABI version.
  39  * If the ABI version is not determined yet (lttng_kernel_use_old_abi = -1),
  40  * this function tests if the new ABI is available and otherwise fallbacks
  41  * on the old one.
  42  * This function takes the fd on which the ioctl must be executed and the old
  43  * and new request codes.
  44  * It returns the return value of the ioctl executed.
  45  */
  46 static inline int compat_ioctl_no_arg(int fd, unsigned long oldname,
  47                 unsigned long newname)
  48 {
  49         int ret;
  50
  51         if (lttng_kernel_use_old_abi == -1) {
  52                 ret = ioctl(fd, newname);
  53                 if (!ret) {
  54                         lttng_kernel_use_old_abi = 0;
  55                         goto end;
  56                 }
  57                 lttng_kernel_use_old_abi = 1;
  58         }
  59         if (lttng_kernel_use_old_abi) {
  60                 ret = ioctl(fd, oldname);
  61         } else {
  62                 ret = ioctl(fd, newname);
  63         }
  64
  65 end:
  66         return ret;
  67 }
  68
  69 int kernctl_create_session(int fd)
  70 {
  71         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION,
  72                         LTTNG_KERNEL_SESSION);
  73 }
  74
  75 /* open the metadata global channel */
  76 int kernctl_open_metadata(int fd, struct lttng_channel_attr *chops)
  77 {
  78         struct lttng_kernel_old_channel old_channel;
  79         struct lttng_kernel_channel channel;
  80
  81         if (lttng_kernel_use_old_abi) {
  82                 old_channel.overwrite = chops->overwrite;
  83                 old_channel.subbuf_size = chops->subbuf_size;
  84                 old_channel.num_subbuf = chops->num_subbuf;
  85                 old_channel.switch_timer_interval = chops->switch_timer_interval;
  86                 old_channel.read_timer_interval = chops->read_timer_interval;
  87                 old_channel.output = chops->output;
  88
  89                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
  90                 /*
  91                  * The new channel padding is smaller than the old ABI so we use the
  92                  * new ABI padding size for the memcpy.
  93                  */
  94                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
  95
  96                 return ioctl(fd, LTTNG_KERNEL_OLD_METADATA, &old_channel);
  97         }
  98
  99         channel.overwrite = chops->overwrite;
 100         channel.subbuf_size = chops->subbuf_size;
 101         channel.num_subbuf = chops->num_subbuf;
 102         channel.switch_timer_interval = chops->switch_timer_interval;
 103         channel.read_timer_interval = chops->read_timer_interval;
 104         channel.output = chops->output;
 105         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 106
 107         return ioctl(fd, LTTNG_KERNEL_METADATA, &channel);
 108 }
 109
 110 int kernctl_create_channel(int fd, struct lttng_channel_attr *chops)
 111 {
 112         struct lttng_kernel_channel channel;
 113
 114         memset(&channel, 0, sizeof(channel));
 115         if (lttng_kernel_use_old_abi) {
 116                 struct lttng_kernel_old_channel old_channel;
 117
 118                 old_channel.overwrite = chops->overwrite;
 119                 old_channel.subbuf_size = chops->subbuf_size;
 120                 old_channel.num_subbuf = chops->num_subbuf;
 121                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 122                 old_channel.read_timer_interval = chops->read_timer_interval;
 123                 old_channel.output = chops->output;
 124
 125                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 126                 /*
 127                  * The new channel padding is smaller than the old ABI so we use the
 128                  * new ABI padding size for the memcpy.
 129                  */
 130                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 131
 132                 return ioctl(fd, LTTNG_KERNEL_OLD_CHANNEL, &old_channel);
 133         }
 134
 135         channel.overwrite = chops->overwrite;
 136         channel.subbuf_size = chops->subbuf_size;
 137         channel.num_subbuf = chops->num_subbuf;
 138         channel.switch_timer_interval = chops->switch_timer_interval;
 139         channel.read_timer_interval = chops->read_timer_interval;
 140         channel.output = chops->output;
 141         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 142
 143         return ioctl(fd, LTTNG_KERNEL_CHANNEL, &channel);
 144 }
 145
 146 int kernctl_syscall_mask(int fd, char **syscall_mask, uint32_t *nr_bits)
 147 {
 148         struct lttng_kernel_syscall_mask kmask_len, *kmask = NULL;
 149         size_t array_alloc_len;
 150         char *new_mask;
 151         int ret = 0;
 152
 153         if (!syscall_mask) {
 154                 ret = -1;
 155                 goto end;
 156         }
 157
 158         if (!nr_bits) {
 159                 ret = -1;
 160                 goto end;
 161         }
 162
 163         kmask_len.len = 0;
 164         ret = ioctl(fd, LTTNG_KERNEL_SYSCALL_MASK, &kmask_len);
 165         if (ret) {
 166                 goto end;
 167         }
 168
 169         array_alloc_len = ALIGN(kmask_len.len, 8) >> 3;
 170
 171         kmask = zmalloc(sizeof(*kmask) + array_alloc_len);
 172         if (!kmask) {
 173                 ret = -1;
 174                 goto end;
 175         }
 176
 177         kmask->len = kmask_len.len;
 178         ret = ioctl(fd, LTTNG_KERNEL_SYSCALL_MASK, kmask);
 179         if (ret) {
 180                 goto end;
 181         }
 182
 183         new_mask = realloc(*syscall_mask, array_alloc_len);
 184         if (!new_mask) {
 185                 ret = -1;
 186                 goto end;
 187         }
 188         memcpy(new_mask, kmask->mask, array_alloc_len);
 189         *syscall_mask = new_mask;
 190         *nr_bits = kmask->len;
 191
 192 end:
 193         free(kmask);
 194         return ret;
 195 }
 196
 197 int kernctl_track_pid(int fd, int pid)
 198 {
 199         return ioctl(fd, LTTNG_KERNEL_SESSION_TRACK_PID, pid);
 200 }
 201
 202 int kernctl_untrack_pid(int fd, int pid)
 203 {
 204         return ioctl(fd, LTTNG_KERNEL_SESSION_UNTRACK_PID, pid);
 205 }
 206
 207 int kernctl_list_tracker_pids(int fd)
 208 {
 209         return ioctl(fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS);
 210 }
 211
 212 int kernctl_create_stream(int fd)
 213 {
 214         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 215                         LTTNG_KERNEL_STREAM);
 216 }
 217
 218 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 219 {
 220         if (lttng_kernel_use_old_abi) {
 221                 struct lttng_kernel_old_event old_event;
 222
 223                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 224                 old_event.instrumentation = ev->instrumentation;
 225                 switch (ev->instrumentation) {
 226                 case LTTNG_KERNEL_KPROBE:
 227                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 228                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 229                         memcpy(old_event.u.kprobe.symbol_name,
 230                                 ev->u.kprobe.symbol_name,
 231                                 sizeof(old_event.u.kprobe.symbol_name));
 232                         break;
 233                 case LTTNG_KERNEL_KRETPROBE:
 234                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 235                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 236                         memcpy(old_event.u.kretprobe.symbol_name,
 237                                 ev->u.kretprobe.symbol_name,
 238                                 sizeof(old_event.u.kretprobe.symbol_name));
 239                         break;
 240                 case LTTNG_KERNEL_FUNCTION:
 241                         memcpy(old_event.u.ftrace.symbol_name,
 242                                         ev->u.ftrace.symbol_name,
 243                                         sizeof(old_event.u.ftrace.symbol_name));
 244                         break;
 245                 default:
 246                         break;
 247                 }
 248
 249                 return ioctl(fd, LTTNG_KERNEL_OLD_EVENT, &old_event);
 250         }
 251         return ioctl(fd, LTTNG_KERNEL_EVENT, ev);
 252 }
 253
 254 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 255 {
 256         if (lttng_kernel_use_old_abi) {
 257                 struct lttng_kernel_old_context old_ctx;
 258
 259                 old_ctx.ctx = ctx->ctx;
 260                 /* only type that uses the union */
 261                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 262                         old_ctx.u.perf_counter.type =
 263                                 ctx->u.perf_counter.type;
 264                         old_ctx.u.perf_counter.config =
 265                                 ctx->u.perf_counter.config;
 266                         memcpy(old_ctx.u.perf_counter.name,
 267                                 ctx->u.perf_counter.name,
 268                                 sizeof(old_ctx.u.perf_counter.name));
 269                 }
 270                 return ioctl(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 271         }
 272         return ioctl(fd, LTTNG_KERNEL_CONTEXT, ctx);
 273 }
 274
 275
 276 /* Enable event, channel and session ioctl */
 277 int kernctl_enable(int fd)
 278 {
 279         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 280                         LTTNG_KERNEL_ENABLE);
 281 }
 282
 283 /* Disable event, channel and session ioctl */
 284 int kernctl_disable(int fd)
 285 {
 286         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 287                         LTTNG_KERNEL_DISABLE);
 288 }
 289
 290 int kernctl_start_session(int fd)
 291 {
 292         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 293                         LTTNG_KERNEL_SESSION_START);
 294 }
 295
 296 int kernctl_stop_session(int fd)
 297 {
 298         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 299                         LTTNG_KERNEL_SESSION_STOP);
 300 }
 301
 302 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter)
 303 {
 304         struct lttng_kernel_filter_bytecode *kb;
 305         uint32_t len;
 306         int ret;
 307
 308         /* Translate bytecode to kernel bytecode */
 309         kb = zmalloc(sizeof(*kb) + filter->len);
 310         if (!kb)
 311                 return -ENOMEM;
 312         kb->len = len = filter->len;
 313         kb->reloc_offset = filter->reloc_table_offset;
 314         kb->seqnum = filter->seqnum;
 315         memcpy(kb->data, filter->data, len);
 316         ret = ioctl(fd, LTTNG_KERNEL_FILTER, kb);
 317         free(kb);
 318         return ret;
 319 }
 320
 321 int kernctl_tracepoint_list(int fd)
 322 {
 323         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 324                         LTTNG_KERNEL_TRACEPOINT_LIST);
 325 }
 326
 327 int kernctl_syscall_list(int fd)
 328 {
 329         return ioctl(fd, LTTNG_KERNEL_SYSCALL_LIST);
 330 }
 331
 332 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 333 {
 334         int ret;
 335
 336         if (lttng_kernel_use_old_abi == -1) {
 337                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 338                 if (!ret) {
 339                         lttng_kernel_use_old_abi = 0;
 340                         goto end;
 341                 }
 342                 lttng_kernel_use_old_abi = 1;
 343         }
 344         if (lttng_kernel_use_old_abi) {
 345                 struct lttng_kernel_old_tracer_version old_v;
 346
 347                 ret = ioctl(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 348                 if (ret) {
 349                         goto end;
 350                 }
 351                 v->major = old_v.major;
 352                 v->minor = old_v.minor;
 353                 v->patchlevel = old_v.patchlevel;
 354         } else {
 355                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 356         }
 357
 358 end:
 359         return ret;
 360 }
 361
 362 int kernctl_tracer_abi_version(int fd,
 363                 struct lttng_kernel_tracer_abi_version *v)
 364 {
 365         return ioctl(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 366 }
 367
 368 int kernctl_wait_quiescent(int fd)
 369 {
 370         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 371                         LTTNG_KERNEL_WAIT_QUIESCENT);
 372 }
 373
 374 int kernctl_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
 375 {
 376         int ret;
 377
 378         if (lttng_kernel_use_old_abi == -1) {
 379                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 380                 if (!ret) {
 381                         lttng_kernel_use_old_abi = 0;
 382                         goto end;
 383                 }
 384                 lttng_kernel_use_old_abi = 1;
 385         }
 386         if (lttng_kernel_use_old_abi) {
 387                 struct lttng_kernel_old_calibrate old_calibrate;
 388
 389                 old_calibrate.type = calibrate->type;
 390                 ret = ioctl(fd, LTTNG_KERNEL_OLD_CALIBRATE, &old_calibrate);
 391                 if (ret) {
 392                         goto end;
 393                 }
 394                 calibrate->type = old_calibrate.type;
 395         } else {
 396                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 397         }
 398
 399 end:
 400         return ret;
 401 }
 402
 403
 404 int kernctl_buffer_flush(int fd)
 405 {
 406         return ioctl(fd, RING_BUFFER_FLUSH);
 407 }
 408
 409
 410 /* Buffer operations */
 411
 412 /* For mmap mode, readable without "get" operation */
 413
 414 /* returns the length to mmap. */
 415 int kernctl_get_mmap_len(int fd, unsigned long *len)
 416 {
 417         return ioctl(fd, RING_BUFFER_GET_MMAP_LEN, len);
 418 }
 419
 420 /* returns the maximum size for sub-buffers. */
 421 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 422 {
 423         return ioctl(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 424 }
 425
 426 /*
 427  * For mmap mode, operate on the current packet (between get/put or
 428  * get_next/put_next).
 429  */
 430
 431 /* returns the offset of the subbuffer belonging to the mmap reader. */
 432 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 433 {
 434         return ioctl(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 435 }
 436
 437 /* returns the size of the current sub-buffer, without padding (for mmap). */
 438 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 439 {
 440         return ioctl(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 441 }
 442
 443 /* returns the size of the current sub-buffer, without padding (for mmap). */
 444 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 445 {
 446         return ioctl(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 447 }
 448
 449 /* Get exclusive read access to the next sub-buffer that can be read. */
 450 int kernctl_get_next_subbuf(int fd)
 451 {
 452         return ioctl(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 453 }
 454
 455
 456 /* Release exclusive sub-buffer access, move consumer forward. */
 457 int kernctl_put_next_subbuf(int fd)
 458 {
 459         return ioctl(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 460 }
 461
 462 /* snapshot */
 463
 464 /* Get a snapshot of the current ring buffer producer and consumer positions */
 465 int kernctl_snapshot(int fd)
 466 {
 467         return ioctl(fd, RING_BUFFER_SNAPSHOT);
 468 }
 469
 470 /* Get the consumer position (iteration start) */
 471 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 472 {
 473         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 474 }
 475
 476 /* Get the producer position (iteration end) */
 477 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 478 {
 479         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 480 }
 481
 482 /* Get exclusive read access to the specified sub-buffer position */
 483 int kernctl_get_subbuf(int fd, unsigned long *len)
 484 {
 485         return ioctl(fd, RING_BUFFER_GET_SUBBUF, len);
 486 }
 487
 488 /* Release exclusive sub-buffer access */
 489 int kernctl_put_subbuf(int fd)
 490 {
 491         return ioctl(fd, RING_BUFFER_PUT_SUBBUF);
 492 }
 493
 494 /* Returns the timestamp begin of the current sub-buffer. */
 495 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 496 {
 497         return ioctl(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN, timestamp_begin);
 498 }
 499
 500 /* Returns the timestamp end of the current sub-buffer. */
 501 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 502 {
 503         return ioctl(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END, timestamp_end);
 504 }
 505
 506 /* Returns the number of discarded events in the current sub-buffer. */
 507 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 508 {
 509         return ioctl(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED, events_discarded);
 510 }
 511
 512 /* Returns the content size in the current sub-buffer. */
 513 int kernctl_get_content_size(int fd, uint64_t *content_size)
 514 {
 515         return ioctl(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE, content_size);
 516 }
 517
 518 /* Returns the packet size in the current sub-buffer. */
 519 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 520 {
 521         return ioctl(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE, packet_size);
 522 }
 523
 524 /* Returns the stream id of the current sub-buffer. */
 525 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 526 {
 527         return ioctl(fd, LTTNG_RING_BUFFER_GET_STREAM_ID, stream_id);
 528 }
 529
 530 /* Returns the current timestamp. */
 531 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 532 {
 533         return ioctl(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP, ts);
 534 }