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_create_stream(int fd)
 143 {
 144         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 145                         LTTNG_KERNEL_STREAM);
 146 }
 147
 148 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 149 {
 150         if (lttng_kernel_use_old_abi) {
 151                 struct lttng_kernel_old_event old_event;
 152
 153                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 154                 old_event.instrumentation = ev->instrumentation;
 155                 switch (ev->instrumentation) {
 156                 case LTTNG_KERNEL_KPROBE:
 157                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 158                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 159                         memcpy(old_event.u.kprobe.symbol_name,
 160                                 ev->u.kprobe.symbol_name,
 161                                 sizeof(old_event.u.kprobe.symbol_name));
 162                         break;
 163                 case LTTNG_KERNEL_KRETPROBE:
 164                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 165                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 166                         memcpy(old_event.u.kretprobe.symbol_name,
 167                                 ev->u.kretprobe.symbol_name,
 168                                 sizeof(old_event.u.kretprobe.symbol_name));
 169                         break;
 170                 case LTTNG_KERNEL_FUNCTION:
 171                         memcpy(old_event.u.ftrace.symbol_name,
 172                                         ev->u.ftrace.symbol_name,
 173                                         sizeof(old_event.u.ftrace.symbol_name));
 174                         break;
 175                 default:
 176                         break;
 177                 }
 178
 179                 return ioctl(fd, LTTNG_KERNEL_OLD_EVENT, &old_event);
 180         }
 181         return ioctl(fd, LTTNG_KERNEL_EVENT, ev);
 182 }
 183
 184 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 185 {
 186         if (lttng_kernel_use_old_abi) {
 187                 struct lttng_kernel_old_context old_ctx;
 188
 189                 old_ctx.ctx = ctx->ctx;
 190                 /* only type that uses the union */
 191                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
 192                         old_ctx.u.perf_counter.type =
 193                                 ctx->u.perf_counter.type;
 194                         old_ctx.u.perf_counter.config =
 195                                 ctx->u.perf_counter.config;
 196                         memcpy(old_ctx.u.perf_counter.name,
 197                                 ctx->u.perf_counter.name,
 198                                 sizeof(old_ctx.u.perf_counter.name));
 199                 }
 200                 return ioctl(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 201         }
 202         return ioctl(fd, LTTNG_KERNEL_CONTEXT, ctx);
 203 }
 204
 205
 206 /* Enable event, channel and session ioctl */
 207 int kernctl_enable(int fd)
 208 {
 209         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 210                         LTTNG_KERNEL_ENABLE);
 211 }
 212
 213 /* Disable event, channel and session ioctl */
 214 int kernctl_disable(int fd)
 215 {
 216         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 217                         LTTNG_KERNEL_DISABLE);
 218 }
 219
 220 int kernctl_start_session(int fd)
 221 {
 222         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 223                         LTTNG_KERNEL_SESSION_START);
 224 }
 225
 226 int kernctl_stop_session(int fd)
 227 {
 228         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 229                         LTTNG_KERNEL_SESSION_STOP);
 230 }
 231
 232 int kernctl_tracepoint_list(int fd)
 233 {
 234         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 235                         LTTNG_KERNEL_TRACEPOINT_LIST);
 236 }
 237
 238 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 239 {
 240         int ret;
 241
 242         if (lttng_kernel_use_old_abi == -1) {
 243                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 244                 if (!ret) {
 245                         lttng_kernel_use_old_abi = 0;
 246                         goto end;
 247                 }
 248                 lttng_kernel_use_old_abi = 1;
 249         }
 250         if (lttng_kernel_use_old_abi) {
 251                 struct lttng_kernel_old_tracer_version old_v;
 252
 253                 ret = ioctl(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 254                 if (ret) {
 255                         goto end;
 256                 }
 257                 v->major = old_v.major;
 258                 v->minor = old_v.minor;
 259                 v->patchlevel = old_v.patchlevel;
 260         } else {
 261                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 262         }
 263
 264 end:
 265         return ret;
 266 }
 267
 268 int kernctl_wait_quiescent(int fd)
 269 {
 270         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 271                         LTTNG_KERNEL_WAIT_QUIESCENT);
 272 }
 273
 274 int kernctl_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
 275 {
 276         int ret;
 277
 278         if (lttng_kernel_use_old_abi == -1) {
 279                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 280                 if (!ret) {
 281                         lttng_kernel_use_old_abi = 0;
 282                         goto end;
 283                 }
 284                 lttng_kernel_use_old_abi = 1;
 285         }
 286         if (lttng_kernel_use_old_abi) {
 287                 struct lttng_kernel_old_calibrate old_calibrate;
 288
 289                 old_calibrate.type = calibrate->type;
 290                 ret = ioctl(fd, LTTNG_KERNEL_OLD_CALIBRATE, &old_calibrate);
 291                 if (ret) {
 292                         goto end;
 293                 }
 294                 calibrate->type = old_calibrate.type;
 295         } else {
 296                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 297         }
 298
 299 end:
 300         return ret;
 301 }
 302
 303
 304 int kernctl_buffer_flush(int fd)
 305 {
 306         return ioctl(fd, RING_BUFFER_FLUSH);
 307 }
 308
 309
 310 /* Buffer operations */
 311
 312 /* For mmap mode, readable without "get" operation */
 313
 314 /* returns the length to mmap. */
 315 int kernctl_get_mmap_len(int fd, unsigned long *len)
 316 {
 317         return ioctl(fd, RING_BUFFER_GET_MMAP_LEN, len);
 318 }
 319
 320 /* returns the maximum size for sub-buffers. */
 321 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 322 {
 323         return ioctl(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 324 }
 325
 326 /*
 327  * For mmap mode, operate on the current packet (between get/put or
 328  * get_next/put_next).
 329  */
 330
 331 /* returns the offset of the subbuffer belonging to the mmap reader. */
 332 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 333 {
 334         return ioctl(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 335 }
 336
 337 /* returns the size of the current sub-buffer, without padding (for mmap). */
 338 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 339 {
 340         return ioctl(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 341 }
 342
 343 /* returns the size of the current sub-buffer, without padding (for mmap). */
 344 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 345 {
 346         return ioctl(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 347 }
 348
 349 /* Get exclusive read access to the next sub-buffer that can be read. */
 350 int kernctl_get_next_subbuf(int fd)
 351 {
 352         return ioctl(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 353 }
 354
 355
 356 /* Release exclusive sub-buffer access, move consumer forward. */
 357 int kernctl_put_next_subbuf(int fd)
 358 {
 359         return ioctl(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 360 }
 361
 362 /* snapshot */
 363
 364 /* Get a snapshot of the current ring buffer producer and consumer positions */
 365 int kernctl_snapshot(int fd)
 366 {
 367         return ioctl(fd, RING_BUFFER_SNAPSHOT);
 368 }
 369
 370 /* Get the consumer position (iteration start) */
 371 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 372 {
 373         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 374 }
 375
 376 /* Get the producer position (iteration end) */
 377 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 378 {
 379         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 380 }
 381
 382 /* Get exclusive read access to the specified sub-buffer position */
 383 int kernctl_get_subbuf(int fd, unsigned long *len)
 384 {
 385         return ioctl(fd, RING_BUFFER_GET_SUBBUF, len);
 386 }
 387
 388 /* Release exclusive sub-buffer access */
 389 int kernctl_put_subbuf(int fd)
 390 {
 391         return ioctl(fd, RING_BUFFER_PUT_SUBBUF);
 392 }