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