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
  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         if (lttng_kernel_use_old_abi) {
 115                 struct lttng_kernel_old_channel old_channel;
 116
 117                 old_channel.overwrite = chops->overwrite;
 118                 old_channel.subbuf_size = chops->subbuf_size;
 119                 old_channel.num_subbuf = chops->num_subbuf;
 120                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 121                 old_channel.read_timer_interval = chops->read_timer_interval;
 122                 old_channel.output = chops->output;
 123
 124                 memset(old_channel.padding, 0, sizeof(old_channel.padding));
 125                 /*
 126                  * The new channel padding is smaller than the old ABI so we use the
 127                  * new ABI padding size for the memcpy.
 128                  */
 129                 memcpy(old_channel.padding, chops->padding, sizeof(chops->padding));
 130
 131                 return ioctl(fd, LTTNG_KERNEL_OLD_CHANNEL, &old_channel);
 132         }
 133
 134         channel.overwrite = chops->overwrite;
 135         channel.subbuf_size = chops->subbuf_size;
 136         channel.num_subbuf = chops->num_subbuf;
 137         channel.switch_timer_interval = chops->switch_timer_interval;
 138         channel.read_timer_interval = chops->read_timer_interval;
 139         channel.output = chops->output;
 140         memcpy(channel.padding, chops->padding, sizeof(chops->padding));
 141
 142         return ioctl(fd, LTTNG_KERNEL_CHANNEL, &channel);
 143 }
 144
 145 int kernctl_enable_syscall(int fd, const char *syscall_name)
 146 {
 147         struct lttng_kernel_event event;
 148
 149         memset(&event, 0, sizeof(event));
 150         strncpy(event.name, syscall_name, sizeof(event.name));
 151         event.name[sizeof(event.name) - 1] = '\0';
 152         event.instrumentation = LTTNG_KERNEL_SYSCALL;
 153         event.u.syscall.enable = 1;
 154         return ioctl(fd, LTTNG_KERNEL_EVENT, &event);
 155 }
 156
 157 int kernctl_disable_syscall(int fd, const char *syscall_name)
 158 {
 159         struct lttng_kernel_event event;
 160
 161         memset(&event, 0, sizeof(event));
 162         strncpy(event.name, syscall_name, sizeof(event.name));
 163         event.name[sizeof(event.name) - 1] = '\0';
 164         event.instrumentation = LTTNG_KERNEL_SYSCALL;
 165         event.u.syscall.enable = 0;
 166         return ioctl(fd, LTTNG_KERNEL_EVENT, &event);
 167 }
 168
 169 int kernctl_syscall_mask(int fd, char **syscall_mask, uint32_t *nr_bits)
 170 {
 171         struct lttng_kernel_syscall_mask kmask_len, *kmask = NULL;
 172         size_t array_alloc_len;
 173         char *new_mask;
 174         int ret = 0;
 175
 176         if (!syscall_mask) {
 177                 ret = -1;
 178                 goto end;
 179         }
 180
 181         if (!nr_bits) {
 182                 ret = -1;
 183                 goto end;
 184         }
 185
 186         kmask_len.len = 0;
 187         ret = ioctl(fd, LTTNG_KERNEL_SYSCALL_MASK, &kmask_len);
 188         if (ret) {
 189                 goto end;
 190         }
 191
 192         array_alloc_len = ALIGN(kmask_len.len, 8) >> 3;
 193
 194         kmask = zmalloc(sizeof(*kmask) + array_alloc_len);
 195         if (!kmask) {
 196                 ret = -1;
 197                 goto end;
 198         }
 199
 200         kmask->len = kmask_len.len;
 201         ret = ioctl(fd, LTTNG_KERNEL_SYSCALL_MASK, kmask);
 202         if (ret) {
 203                 goto end;
 204         }
 205
 206         new_mask = realloc(*syscall_mask, array_alloc_len);
 207         if (!new_mask) {
 208                 ret = -1;
 209                 goto end;
 210         }
 211         memcpy(new_mask, kmask->mask, array_alloc_len);
 212         *syscall_mask = new_mask;
 213         *nr_bits = kmask->len;
 214
 215 end:
 216         free(kmask);
 217         return ret;
 218 }
 219
 220 int kernctl_track_pid(int fd, int pid)
 221 {
 222         return ioctl(fd, LTTNG_KERNEL_SESSION_TRACK_PID, pid);
 223 }
 224
 225 int kernctl_untrack_pid(int fd, int pid)
 226 {
 227         return ioctl(fd, LTTNG_KERNEL_SESSION_UNTRACK_PID, pid);
 228 }
 229
 230 int kernctl_create_stream(int fd)
 231 {
 232         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 233                         LTTNG_KERNEL_STREAM);
 234 }
 235
 236 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 237 {
 238         if (lttng_kernel_use_old_abi) {
 239                 struct lttng_kernel_old_event old_event;
 240
 241                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 242                 old_event.instrumentation = ev->instrumentation;
 243                 switch (ev->instrumentation) {
 244                 case LTTNG_KERNEL_KPROBE:
 245                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 246                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 247                         memcpy(old_event.u.kprobe.symbol_name,
 248                                 ev->u.kprobe.symbol_name,
 249                                 sizeof(old_event.u.kprobe.symbol_name));
 250                         break;
 251                 case LTTNG_KERNEL_KRETPROBE:
 252                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 253                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 254                         memcpy(old_event.u.kretprobe.symbol_name,
 255                                 ev->u.kretprobe.symbol_name,
 256                                 sizeof(old_event.u.kretprobe.symbol_name));
 257                         break;
 258                 case LTTNG_KERNEL_FUNCTION:
 259                         memcpy(old_event.u.ftrace.symbol_name,
 260                                         ev->u.ftrace.symbol_name,
 261                                         sizeof(old_event.u.ftrace.symbol_name));
 262                         break;
 263                 default:
 264                         break;
 265                 }
 266
 267                 return ioctl(fd, LTTNG_KERNEL_OLD_EVENT, &old_event);
 268         }
 269         return ioctl(fd, LTTNG_KERNEL_EVENT, ev);
 270 }
 271
 272 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 273 {
 274         if (lttng_kernel_use_old_abi) {
 275                 struct lttng_kernel_old_context old_ctx;
 276
 277                 old_ctx.ctx = ctx->ctx;
 278                 /* only type that uses the union */
 279                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 280                         old_ctx.u.perf_counter.type =
 281                                 ctx->u.perf_counter.type;
 282                         old_ctx.u.perf_counter.config =
 283                                 ctx->u.perf_counter.config;
 284                         memcpy(old_ctx.u.perf_counter.name,
 285                                 ctx->u.perf_counter.name,
 286                                 sizeof(old_ctx.u.perf_counter.name));
 287                 }
 288                 return ioctl(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 289         }
 290         return ioctl(fd, LTTNG_KERNEL_CONTEXT, ctx);
 291 }
 292
 293
 294 /* Enable event, channel and session ioctl */
 295 int kernctl_enable(int fd)
 296 {
 297         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 298                         LTTNG_KERNEL_ENABLE);
 299 }
 300
 301 /* Disable event, channel and session ioctl */
 302 int kernctl_disable(int fd)
 303 {
 304         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 305                         LTTNG_KERNEL_DISABLE);
 306 }
 307
 308 int kernctl_start_session(int fd)
 309 {
 310         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 311                         LTTNG_KERNEL_SESSION_START);
 312 }
 313
 314 int kernctl_stop_session(int fd)
 315 {
 316         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 317                         LTTNG_KERNEL_SESSION_STOP);
 318 }
 319
 320 int kernctl_tracepoint_list(int fd)
 321 {
 322         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 323                         LTTNG_KERNEL_TRACEPOINT_LIST);
 324 }
 325
 326 int kernctl_syscall_list(int fd)
 327 {
 328         return ioctl(fd, LTTNG_KERNEL_SYSCALL_LIST);
 329 }
 330
 331 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 332 {
 333         int ret;
 334
 335         if (lttng_kernel_use_old_abi == -1) {
 336                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 337                 if (!ret) {
 338                         lttng_kernel_use_old_abi = 0;
 339                         goto end;
 340                 }
 341                 lttng_kernel_use_old_abi = 1;
 342         }
 343         if (lttng_kernel_use_old_abi) {
 344                 struct lttng_kernel_old_tracer_version old_v;
 345
 346                 ret = ioctl(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 347                 if (ret) {
 348                         goto end;
 349                 }
 350                 v->major = old_v.major;
 351                 v->minor = old_v.minor;
 352                 v->patchlevel = old_v.patchlevel;
 353         } else {
 354                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 355         }
 356
 357 end:
 358         return ret;
 359 }
 360
 361 int kernctl_tracer_abi_version(int fd,
 362                 struct lttng_kernel_tracer_abi_version *v)
 363 {
 364         return ioctl(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 365 }
 366
 367 int kernctl_wait_quiescent(int fd)
 368 {
 369         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 370                         LTTNG_KERNEL_WAIT_QUIESCENT);
 371 }
 372
 373 int kernctl_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
 374 {
 375         int ret;
 376
 377         if (lttng_kernel_use_old_abi == -1) {
 378                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 379                 if (!ret) {
 380                         lttng_kernel_use_old_abi = 0;
 381                         goto end;
 382                 }
 383                 lttng_kernel_use_old_abi = 1;
 384         }
 385         if (lttng_kernel_use_old_abi) {
 386                 struct lttng_kernel_old_calibrate old_calibrate;
 387
 388                 old_calibrate.type = calibrate->type;
 389                 ret = ioctl(fd, LTTNG_KERNEL_OLD_CALIBRATE, &old_calibrate);
 390                 if (ret) {
 391                         goto end;
 392                 }
 393                 calibrate->type = old_calibrate.type;
 394         } else {
 395                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 396         }
 397
 398 end:
 399         return ret;
 400 }
 401
 402
 403 int kernctl_buffer_flush(int fd)
 404 {
 405         return ioctl(fd, RING_BUFFER_FLUSH);
 406 }
 407
 408
 409 /* Buffer operations */
 410
 411 /* For mmap mode, readable without "get" operation */
 412
 413 /* returns the length to mmap. */
 414 int kernctl_get_mmap_len(int fd, unsigned long *len)
 415 {
 416         return ioctl(fd, RING_BUFFER_GET_MMAP_LEN, len);
 417 }
 418
 419 /* returns the maximum size for sub-buffers. */
 420 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 421 {
 422         return ioctl(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 423 }
 424
 425 /*
 426  * For mmap mode, operate on the current packet (between get/put or
 427  * get_next/put_next).
 428  */
 429
 430 /* returns the offset of the subbuffer belonging to the mmap reader. */
 431 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 432 {
 433         return ioctl(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 434 }
 435
 436 /* returns the size of the current sub-buffer, without padding (for mmap). */
 437 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 438 {
 439         return ioctl(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 440 }
 441
 442 /* returns the size of the current sub-buffer, without padding (for mmap). */
 443 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 444 {
 445         return ioctl(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 446 }
 447
 448 /* Get exclusive read access to the next sub-buffer that can be read. */
 449 int kernctl_get_next_subbuf(int fd)
 450 {
 451         return ioctl(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 452 }
 453
 454
 455 /* Release exclusive sub-buffer access, move consumer forward. */
 456 int kernctl_put_next_subbuf(int fd)
 457 {
 458         return ioctl(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 459 }
 460
 461 /* snapshot */
 462
 463 /* Get a snapshot of the current ring buffer producer and consumer positions */
 464 int kernctl_snapshot(int fd)
 465 {
 466         return ioctl(fd, RING_BUFFER_SNAPSHOT);
 467 }
 468
 469 /* Get the consumer position (iteration start) */
 470 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 471 {
 472         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 473 }
 474
 475 /* Get the producer position (iteration end) */
 476 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 477 {
 478         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 479 }
 480
 481 /* Get exclusive read access to the specified sub-buffer position */
 482 int kernctl_get_subbuf(int fd, unsigned long *len)
 483 {
 484         return ioctl(fd, RING_BUFFER_GET_SUBBUF, len);
 485 }
 486
 487 /* Release exclusive sub-buffer access */
 488 int kernctl_put_subbuf(int fd)
 489 {
 490         return ioctl(fd, RING_BUFFER_PUT_SUBBUF);
 491 }
 492
 493 /* Returns the timestamp begin of the current sub-buffer. */
 494 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 495 {
 496         return ioctl(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN, timestamp_begin);
 497 }
 498
 499 /* Returns the timestamp end of the current sub-buffer. */
 500 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 501 {
 502         return ioctl(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END, timestamp_end);
 503 }
 504
 505 /* Returns the number of discarded events in the current sub-buffer. */
 506 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 507 {
 508         return ioctl(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED, events_discarded);
 509 }
 510
 511 /* Returns the content size in the current sub-buffer. */
 512 int kernctl_get_content_size(int fd, uint64_t *content_size)
 513 {
 514         return ioctl(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE, content_size);
 515 }
 516
 517 /* Returns the packet size in the current sub-buffer. */
 518 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 519 {
 520         return ioctl(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE, packet_size);
 521 }
 522
 523 /* Returns the stream id of the current sub-buffer. */
 524 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 525 {
 526         return ioctl(fd, LTTNG_RING_BUFFER_GET_STREAM_ID, stream_id);
 527 }
 528
 529 /* Returns the current timestamp. */
 530 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 531 {
 532         return ioctl(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP, ts);
 533 }