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