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