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_list_tracker_pids(int fd)
 231 {
 232         return ioctl(fd, LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS);
 233 }
 234
 235 int kernctl_create_stream(int fd)
 236 {
 237         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 238                         LTTNG_KERNEL_STREAM);
 239 }
 240
 241 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 242 {
 243         if (lttng_kernel_use_old_abi) {
 244                 struct lttng_kernel_old_event old_event;
 245
 246                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 247                 old_event.instrumentation = ev->instrumentation;
 248                 switch (ev->instrumentation) {
 249                 case LTTNG_KERNEL_KPROBE:
 250                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 251                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 252                         memcpy(old_event.u.kprobe.symbol_name,
 253                                 ev->u.kprobe.symbol_name,
 254                                 sizeof(old_event.u.kprobe.symbol_name));
 255                         break;
 256                 case LTTNG_KERNEL_KRETPROBE:
 257                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 258                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 259                         memcpy(old_event.u.kretprobe.symbol_name,
 260                                 ev->u.kretprobe.symbol_name,
 261                                 sizeof(old_event.u.kretprobe.symbol_name));
 262                         break;
 263                 case LTTNG_KERNEL_FUNCTION:
 264                         memcpy(old_event.u.ftrace.symbol_name,
 265                                         ev->u.ftrace.symbol_name,
 266                                         sizeof(old_event.u.ftrace.symbol_name));
 267                         break;
 268                 default:
 269                         break;
 270                 }
 271
 272                 return ioctl(fd, LTTNG_KERNEL_OLD_EVENT, &old_event);
 273         }
 274         return ioctl(fd, LTTNG_KERNEL_EVENT, ev);
 275 }
 276
 277 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 278 {
 279         if (lttng_kernel_use_old_abi) {
 280                 struct lttng_kernel_old_context old_ctx;
 281
 282                 old_ctx.ctx = ctx->ctx;
 283                 /* only type that uses the union */
 284                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
 285                         old_ctx.u.perf_counter.type =
 286                                 ctx->u.perf_counter.type;
 287                         old_ctx.u.perf_counter.config =
 288                                 ctx->u.perf_counter.config;
 289                         memcpy(old_ctx.u.perf_counter.name,
 290                                 ctx->u.perf_counter.name,
 291                                 sizeof(old_ctx.u.perf_counter.name));
 292                 }
 293                 return ioctl(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 294         }
 295         return ioctl(fd, LTTNG_KERNEL_CONTEXT, ctx);
 296 }
 297
 298
 299 /* Enable event, channel and session ioctl */
 300 int kernctl_enable(int fd)
 301 {
 302         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 303                         LTTNG_KERNEL_ENABLE);
 304 }
 305
 306 /* Disable event, channel and session ioctl */
 307 int kernctl_disable(int fd)
 308 {
 309         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 310                         LTTNG_KERNEL_DISABLE);
 311 }
 312
 313 int kernctl_start_session(int fd)
 314 {
 315         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 316                         LTTNG_KERNEL_SESSION_START);
 317 }
 318
 319 int kernctl_stop_session(int fd)
 320 {
 321         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 322                         LTTNG_KERNEL_SESSION_STOP);
 323 }
 324
 325 int kernctl_tracepoint_list(int fd)
 326 {
 327         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 328                         LTTNG_KERNEL_TRACEPOINT_LIST);
 329 }
 330
 331 int kernctl_syscall_list(int fd)
 332 {
 333         return ioctl(fd, LTTNG_KERNEL_SYSCALL_LIST);
 334 }
 335
 336 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 337 {
 338         int ret;
 339
 340         if (lttng_kernel_use_old_abi == -1) {
 341                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 342                 if (!ret) {
 343                         lttng_kernel_use_old_abi = 0;
 344                         goto end;
 345                 }
 346                 lttng_kernel_use_old_abi = 1;
 347         }
 348         if (lttng_kernel_use_old_abi) {
 349                 struct lttng_kernel_old_tracer_version old_v;
 350
 351                 ret = ioctl(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 352                 if (ret) {
 353                         goto end;
 354                 }
 355                 v->major = old_v.major;
 356                 v->minor = old_v.minor;
 357                 v->patchlevel = old_v.patchlevel;
 358         } else {
 359                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 360         }
 361
 362 end:
 363         return ret;
 364 }
 365
 366 int kernctl_tracer_abi_version(int fd,
 367                 struct lttng_kernel_tracer_abi_version *v)
 368 {
 369         return ioctl(fd, LTTNG_KERNEL_TRACER_ABI_VERSION, v);
 370 }
 371
 372 int kernctl_wait_quiescent(int fd)
 373 {
 374         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 375                         LTTNG_KERNEL_WAIT_QUIESCENT);
 376 }
 377
 378 int kernctl_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
 379 {
 380         int ret;
 381
 382         if (lttng_kernel_use_old_abi == -1) {
 383                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 384                 if (!ret) {
 385                         lttng_kernel_use_old_abi = 0;
 386                         goto end;
 387                 }
 388                 lttng_kernel_use_old_abi = 1;
 389         }
 390         if (lttng_kernel_use_old_abi) {
 391                 struct lttng_kernel_old_calibrate old_calibrate;
 392
 393                 old_calibrate.type = calibrate->type;
 394                 ret = ioctl(fd, LTTNG_KERNEL_OLD_CALIBRATE, &old_calibrate);
 395                 if (ret) {
 396                         goto end;
 397                 }
 398                 calibrate->type = old_calibrate.type;
 399         } else {
 400                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 401         }
 402
 403 end:
 404         return ret;
 405 }
 406
 407
 408 int kernctl_buffer_flush(int fd)
 409 {
 410         return ioctl(fd, RING_BUFFER_FLUSH);
 411 }
 412
 413
 414 /* Buffer operations */
 415
 416 /* For mmap mode, readable without "get" operation */
 417
 418 /* returns the length to mmap. */
 419 int kernctl_get_mmap_len(int fd, unsigned long *len)
 420 {
 421         return ioctl(fd, RING_BUFFER_GET_MMAP_LEN, len);
 422 }
 423
 424 /* returns the maximum size for sub-buffers. */
 425 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 426 {
 427         return ioctl(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 428 }
 429
 430 /*
 431  * For mmap mode, operate on the current packet (between get/put or
 432  * get_next/put_next).
 433  */
 434
 435 /* returns the offset of the subbuffer belonging to the mmap reader. */
 436 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 437 {
 438         return ioctl(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 439 }
 440
 441 /* returns the size of the current sub-buffer, without padding (for mmap). */
 442 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 443 {
 444         return ioctl(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 445 }
 446
 447 /* returns the size of the current sub-buffer, without padding (for mmap). */
 448 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 449 {
 450         return ioctl(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 451 }
 452
 453 /* Get exclusive read access to the next sub-buffer that can be read. */
 454 int kernctl_get_next_subbuf(int fd)
 455 {
 456         return ioctl(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 457 }
 458
 459
 460 /* Release exclusive sub-buffer access, move consumer forward. */
 461 int kernctl_put_next_subbuf(int fd)
 462 {
 463         return ioctl(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 464 }
 465
 466 /* snapshot */
 467
 468 /* Get a snapshot of the current ring buffer producer and consumer positions */
 469 int kernctl_snapshot(int fd)
 470 {
 471         return ioctl(fd, RING_BUFFER_SNAPSHOT);
 472 }
 473
 474 /* Get the consumer position (iteration start) */
 475 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 476 {
 477         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 478 }
 479
 480 /* Get the producer position (iteration end) */
 481 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 482 {
 483         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 484 }
 485
 486 /* Get exclusive read access to the specified sub-buffer position */
 487 int kernctl_get_subbuf(int fd, unsigned long *len)
 488 {
 489         return ioctl(fd, RING_BUFFER_GET_SUBBUF, len);
 490 }
 491
 492 /* Release exclusive sub-buffer access */
 493 int kernctl_put_subbuf(int fd)
 494 {
 495         return ioctl(fd, RING_BUFFER_PUT_SUBBUF);
 496 }
 497
 498 /* Returns the timestamp begin of the current sub-buffer. */
 499 int kernctl_get_timestamp_begin(int fd, uint64_t *timestamp_begin)
 500 {
 501         return ioctl(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN, timestamp_begin);
 502 }
 503
 504 /* Returns the timestamp end of the current sub-buffer. */
 505 int kernctl_get_timestamp_end(int fd, uint64_t *timestamp_end)
 506 {
 507         return ioctl(fd, LTTNG_RING_BUFFER_GET_TIMESTAMP_END, timestamp_end);
 508 }
 509
 510 /* Returns the number of discarded events in the current sub-buffer. */
 511 int kernctl_get_events_discarded(int fd, uint64_t *events_discarded)
 512 {
 513         return ioctl(fd, LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED, events_discarded);
 514 }
 515
 516 /* Returns the content size in the current sub-buffer. */
 517 int kernctl_get_content_size(int fd, uint64_t *content_size)
 518 {
 519         return ioctl(fd, LTTNG_RING_BUFFER_GET_CONTENT_SIZE, content_size);
 520 }
 521
 522 /* Returns the packet size in the current sub-buffer. */
 523 int kernctl_get_packet_size(int fd, uint64_t *packet_size)
 524 {
 525         return ioctl(fd, LTTNG_RING_BUFFER_GET_PACKET_SIZE, packet_size);
 526 }
 527
 528 /* Returns the stream id of the current sub-buffer. */
 529 int kernctl_get_stream_id(int fd, uint64_t *stream_id)
 530 {
 531         return ioctl(fd, LTTNG_RING_BUFFER_GET_STREAM_ID, stream_id);
 532 }
 533
 534 /* Returns the current timestamp. */
 535 int kernctl_get_current_timestamp(int fd, uint64_t *ts)
 536 {
 537         return ioctl(fd, LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP, ts);
 538 }