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                 memcpy(old_channel.padding, chops->padding, sizeof(old_channel.padding));
  86
  87                 return ioctl(fd, LTTNG_KERNEL_OLD_METADATA, &old_channel);
  88         }
  89
  90         channel.overwrite = chops->overwrite;
  91         channel.subbuf_size = chops->subbuf_size;
  92         channel.num_subbuf = chops->num_subbuf;
  93         channel.switch_timer_interval = chops->switch_timer_interval;
  94         channel.read_timer_interval = chops->read_timer_interval;
  95         channel.output = chops->output;
  96         memcpy(channel.padding, chops->padding, sizeof(channel.padding));
  97
  98         return ioctl(fd, LTTNG_KERNEL_METADATA, &channel);
  99 }
 100
 101 int kernctl_create_channel(int fd, struct lttng_channel_attr *chops)
 102 {
 103         struct lttng_kernel_channel channel;
 104
 105         if (lttng_kernel_use_old_abi) {
 106                 struct lttng_kernel_old_channel old_channel;
 107
 108                 old_channel.overwrite = chops->overwrite;
 109                 old_channel.subbuf_size = chops->subbuf_size;
 110                 old_channel.num_subbuf = chops->num_subbuf;
 111                 old_channel.switch_timer_interval = chops->switch_timer_interval;
 112                 old_channel.read_timer_interval = chops->read_timer_interval;
 113                 old_channel.output = chops->output;
 114                 memcpy(old_channel.padding, chops->padding, sizeof(old_channel.padding));
 115
 116                 return ioctl(fd, LTTNG_KERNEL_OLD_CHANNEL, &old_channel);
 117         }
 118
 119         channel.overwrite = chops->overwrite;
 120         channel.subbuf_size = chops->subbuf_size;
 121         channel.num_subbuf = chops->num_subbuf;
 122         channel.switch_timer_interval = chops->switch_timer_interval;
 123         channel.read_timer_interval = chops->read_timer_interval;
 124         channel.output = chops->output;
 125         memcpy(channel.padding, chops->padding, sizeof(channel.padding));
 126
 127         return ioctl(fd, LTTNG_KERNEL_CHANNEL, &channel);
 128 }
 129
 130 int kernctl_create_stream(int fd)
 131 {
 132         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_STREAM,
 133                         LTTNG_KERNEL_STREAM);
 134 }
 135
 136 int kernctl_create_event(int fd, struct lttng_kernel_event *ev)
 137 {
 138         if (lttng_kernel_use_old_abi) {
 139                 struct lttng_kernel_old_event old_event;
 140
 141                 memcpy(old_event.name, ev->name, sizeof(old_event.name));
 142                 old_event.instrumentation = ev->instrumentation;
 143                 switch (ev->instrumentation) {
 144                 case LTTNG_KERNEL_KPROBE:
 145                         old_event.u.kprobe.addr = ev->u.kprobe.addr;
 146                         old_event.u.kprobe.offset = ev->u.kprobe.offset;
 147                         memcpy(old_event.u.kprobe.symbol_name,
 148                                 ev->u.kprobe.symbol_name,
 149                                 sizeof(old_event.u.kprobe.symbol_name));
 150                         break;
 151                 case LTTNG_KERNEL_KRETPROBE:
 152                         old_event.u.kretprobe.addr = ev->u.kretprobe.addr;
 153                         old_event.u.kretprobe.offset = ev->u.kretprobe.offset;
 154                         memcpy(old_event.u.kretprobe.symbol_name,
 155                                 ev->u.kretprobe.symbol_name,
 156                                 sizeof(old_event.u.kretprobe.symbol_name));
 157                         break;
 158                 case LTTNG_KERNEL_FUNCTION:
 159                         memcpy(old_event.u.ftrace.symbol_name,
 160                                         ev->u.ftrace.symbol_name,
 161                                         sizeof(old_event.u.ftrace.symbol_name));
 162                         break;
 163                 default:
 164                         break;
 165                 }
 166
 167                 return ioctl(fd, LTTNG_KERNEL_OLD_EVENT, &old_event);
 168         }
 169         return ioctl(fd, LTTNG_KERNEL_EVENT, ev);
 170 }
 171
 172 int kernctl_add_context(int fd, struct lttng_kernel_context *ctx)
 173 {
 174         if (lttng_kernel_use_old_abi) {
 175                 struct lttng_kernel_old_context old_ctx;
 176
 177                 old_ctx.ctx = ctx->ctx;
 178                 /* only type that uses the union */
 179                 if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
 180                         old_ctx.u.perf_counter.type =
 181                                 ctx->u.perf_counter.type;
 182                         old_ctx.u.perf_counter.config =
 183                                 ctx->u.perf_counter.config;
 184                         memcpy(old_ctx.u.perf_counter.name,
 185                                 ctx->u.perf_counter.name,
 186                                 sizeof(old_ctx.u.perf_counter.name));
 187                 }
 188                 return ioctl(fd, LTTNG_KERNEL_OLD_CONTEXT, &old_ctx);
 189         }
 190         return ioctl(fd, LTTNG_KERNEL_CONTEXT, ctx);
 191 }
 192
 193
 194 /* Enable event, channel and session ioctl */
 195 int kernctl_enable(int fd)
 196 {
 197         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_ENABLE,
 198                         LTTNG_KERNEL_ENABLE);
 199 }
 200
 201 /* Disable event, channel and session ioctl */
 202 int kernctl_disable(int fd)
 203 {
 204         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_DISABLE,
 205                         LTTNG_KERNEL_DISABLE);
 206 }
 207
 208 int kernctl_start_session(int fd)
 209 {
 210         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_START,
 211                         LTTNG_KERNEL_SESSION_START);
 212 }
 213
 214 int kernctl_stop_session(int fd)
 215 {
 216         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_SESSION_STOP,
 217                         LTTNG_KERNEL_SESSION_STOP);
 218 }
 219
 220 int kernctl_tracepoint_list(int fd)
 221 {
 222         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_TRACEPOINT_LIST,
 223                         LTTNG_KERNEL_TRACEPOINT_LIST);
 224 }
 225
 226 int kernctl_tracer_version(int fd, struct lttng_kernel_tracer_version *v)
 227 {
 228         int ret;
 229
 230         if (lttng_kernel_use_old_abi == -1) {
 231                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 232                 if (!ret) {
 233                         lttng_kernel_use_old_abi = 0;
 234                         goto end;
 235                 }
 236                 lttng_kernel_use_old_abi = 1;
 237         }
 238         if (lttng_kernel_use_old_abi) {
 239                 struct lttng_kernel_old_tracer_version old_v;
 240
 241                 ret = ioctl(fd, LTTNG_KERNEL_OLD_TRACER_VERSION, &old_v);
 242                 if (ret) {
 243                         goto end;
 244                 }
 245                 v->major = old_v.major;
 246                 v->minor = old_v.minor;
 247                 v->patchlevel = old_v.patchlevel;
 248         } else {
 249                 ret = ioctl(fd, LTTNG_KERNEL_TRACER_VERSION, v);
 250         }
 251
 252 end:
 253         return ret;
 254 }
 255
 256 int kernctl_wait_quiescent(int fd)
 257 {
 258         return compat_ioctl_no_arg(fd, LTTNG_KERNEL_OLD_WAIT_QUIESCENT,
 259                         LTTNG_KERNEL_WAIT_QUIESCENT);
 260 }
 261
 262 int kernctl_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
 263 {
 264         int ret;
 265
 266         if (lttng_kernel_use_old_abi == -1) {
 267                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 268                 if (!ret) {
 269                         lttng_kernel_use_old_abi = 0;
 270                         goto end;
 271                 }
 272                 lttng_kernel_use_old_abi = 1;
 273         }
 274         if (lttng_kernel_use_old_abi) {
 275                 struct lttng_kernel_old_calibrate old_calibrate;
 276
 277                 old_calibrate.type = calibrate->type;
 278                 ret = ioctl(fd, LTTNG_KERNEL_OLD_CALIBRATE, &old_calibrate);
 279                 if (ret) {
 280                         goto end;
 281                 }
 282                 calibrate->type = old_calibrate.type;
 283         } else {
 284                 ret = ioctl(fd, LTTNG_KERNEL_CALIBRATE, calibrate);
 285         }
 286
 287 end:
 288         return ret;
 289 }
 290
 291
 292 int kernctl_buffer_flush(int fd)
 293 {
 294         return ioctl(fd, RING_BUFFER_FLUSH);
 295 }
 296
 297
 298 /* Buffer operations */
 299
 300 /* For mmap mode, readable without "get" operation */
 301
 302 /* returns the length to mmap. */
 303 int kernctl_get_mmap_len(int fd, unsigned long *len)
 304 {
 305         return ioctl(fd, RING_BUFFER_GET_MMAP_LEN, len);
 306 }
 307
 308 /* returns the maximum size for sub-buffers. */
 309 int kernctl_get_max_subbuf_size(int fd, unsigned long *len)
 310 {
 311         return ioctl(fd, RING_BUFFER_GET_MAX_SUBBUF_SIZE, len);
 312 }
 313
 314 /*
 315  * For mmap mode, operate on the current packet (between get/put or
 316  * get_next/put_next).
 317  */
 318
 319 /* returns the offset of the subbuffer belonging to the mmap reader. */
 320 int kernctl_get_mmap_read_offset(int fd, unsigned long *off)
 321 {
 322         return ioctl(fd, RING_BUFFER_GET_MMAP_READ_OFFSET, off);
 323 }
 324
 325 /* returns the size of the current sub-buffer, without padding (for mmap). */
 326 int kernctl_get_subbuf_size(int fd, unsigned long *len)
 327 {
 328         return ioctl(fd, RING_BUFFER_GET_SUBBUF_SIZE, len);
 329 }
 330
 331 /* returns the size of the current sub-buffer, without padding (for mmap). */
 332 int kernctl_get_padded_subbuf_size(int fd, unsigned long *len)
 333 {
 334         return ioctl(fd, RING_BUFFER_GET_PADDED_SUBBUF_SIZE, len);
 335 }
 336
 337 /* Get exclusive read access to the next sub-buffer that can be read. */
 338 int kernctl_get_next_subbuf(int fd)
 339 {
 340         return ioctl(fd, RING_BUFFER_GET_NEXT_SUBBUF);
 341 }
 342
 343
 344 /* Release exclusive sub-buffer access, move consumer forward. */
 345 int kernctl_put_next_subbuf(int fd)
 346 {
 347         return ioctl(fd, RING_BUFFER_PUT_NEXT_SUBBUF);
 348 }
 349
 350 /* snapshot */
 351
 352 /* Get a snapshot of the current ring buffer producer and consumer positions */
 353 int kernctl_snapshot(int fd)
 354 {
 355         return ioctl(fd, RING_BUFFER_SNAPSHOT);
 356 }
 357
 358 /* Get the consumer position (iteration start) */
 359 int kernctl_snapshot_get_consumed(int fd, unsigned long *pos)
 360 {
 361         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_CONSUMED, pos);
 362 }
 363
 364 /* Get the producer position (iteration end) */
 365 int kernctl_snapshot_get_produced(int fd, unsigned long *pos)
 366 {
 367         return ioctl(fd, RING_BUFFER_SNAPSHOT_GET_PRODUCED, pos);
 368 }
 369
 370 /* Get exclusive read access to the specified sub-buffer position */
 371 int kernctl_get_subbuf(int fd, unsigned long *len)
 372 {
 373         return ioctl(fd, RING_BUFFER_GET_SUBBUF, len);
 374 }
 375
 376 /* Release exclusive sub-buffer access */
 377 int kernctl_put_subbuf(int fd)
 378 {
 379         return ioctl(fd, RING_BUFFER_PUT_SUBBUF);
 380 }
 381
 382 /* Set the stream_id */
 383 int kernctl_set_stream_id(int fd, unsigned long *stream_id)
 384 {
 385         return ioctl(fd, RING_BUFFER_SET_STREAM_ID, stream_id);
 386 }