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