lttng-abi.c

   1 /*
   2  * lttng-abi.c
   3  *
   4  * LTTng ABI
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  *
  22  *
  23  * Mimic system calls for:
  24  * - session creation, returns a file descriptor or failure.
  25  *   - channel creation, returns a file descriptor or failure.
  26  *     - Operates on a session file descriptor
  27  *     - Takes all channel options as parameters.
  28  *   - stream get, returns a file descriptor or failure.
  29  *     - Operates on a channel file descriptor.
  30  *   - stream notifier get, returns a file descriptor or failure.
  31  *     - Operates on a channel file descriptor.
  32  *   - event creation, returns a file descriptor or failure.
  33  *     - Operates on a channel file descriptor
  34  *     - Takes an event name as parameter
  35  *     - Takes an instrumentation source as parameter
  36  *       - e.g. tracepoints, dynamic_probes...
  37  *     - Takes instrumentation source specific arguments.
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/proc_fs.h>
  42 #include <linux/anon_inodes.h>
  43 #include <linux/file.h>
  44 #include <linux/uaccess.h>
  45 #include <linux/slab.h>
  46 #include "wrapper/vmalloc.h"    /* for wrapper_vmalloc_sync_all() */
  47 #include "wrapper/ringbuffer/vfs.h"
  48 #include "wrapper/ringbuffer/backend.h"
  49 #include "wrapper/ringbuffer/frontend.h"
  50 #include "wrapper/poll.h"
  51 #include "lttng-abi.h"
  52 #include "lttng-abi-old.h"
  53 #include "lttng-events.h"
  54 #include "lttng-tracer.h"
  55 #include "lib/ringbuffer/frontend_types.h"
  56
  57 /*
  58  * This is LTTng's own personal way to create a system call as an external
  59  * module. We use ioctl() on /proc/lttng.
  60  */
  61
  62 static struct proc_dir_entry *lttng_proc_dentry;
  63 static const struct file_operations lttng_fops;
  64 static const struct file_operations lttng_session_fops;
  65 static const struct file_operations lttng_channel_fops;
  66 static const struct file_operations lttng_metadata_fops;
  67 static const struct file_operations lttng_event_fops;
  68 static struct file_operations lttng_stream_ring_buffer_file_operations;
  69
  70 /*
  71  * Teardown management: opened file descriptors keep a refcount on the module,
  72  * so it can only exit when all file descriptors are closed.
  73  */
  74
  75 static
  76 int lttng_abi_create_session(void)
  77 {
  78         struct lttng_session *session;
  79         struct file *session_file;
  80         int session_fd, ret;
  81
  82         session = lttng_session_create();
  83         if (!session)
  84                 return -ENOMEM;
  85         session_fd = get_unused_fd();
  86         if (session_fd < 0) {
  87                 ret = session_fd;
  88                 goto fd_error;
  89         }
  90         session_file = anon_inode_getfile("[lttng_session]",
  91                                           &lttng_session_fops,
  92                                           session, O_RDWR);
  93         if (IS_ERR(session_file)) {
  94                 ret = PTR_ERR(session_file);
  95                 goto file_error;
  96         }
  97         session->file = session_file;
  98         fd_install(session_fd, session_file);
  99         return session_fd;
 100
 101 file_error:
 102         put_unused_fd(session_fd);
 103 fd_error:
 104         lttng_session_destroy(session);
 105         return ret;
 106 }
 107
 108 static
 109 int lttng_abi_tracepoint_list(void)
 110 {
 111         struct file *tracepoint_list_file;
 112         int file_fd, ret;
 113
 114         file_fd = get_unused_fd();
 115         if (file_fd < 0) {
 116                 ret = file_fd;
 117                 goto fd_error;
 118         }
 119
 120         tracepoint_list_file = anon_inode_getfile("[lttng_session]",
 121                                           &lttng_tracepoint_list_fops,
 122                                           NULL, O_RDWR);
 123         if (IS_ERR(tracepoint_list_file)) {
 124                 ret = PTR_ERR(tracepoint_list_file);
 125                 goto file_error;
 126         }
 127         ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
 128         if (ret < 0)
 129                 goto open_error;
 130         fd_install(file_fd, tracepoint_list_file);
 131         if (file_fd < 0) {
 132                 ret = file_fd;
 133                 goto fd_error;
 134         }
 135         return file_fd;
 136
 137 open_error:
 138         fput(tracepoint_list_file);
 139 file_error:
 140         put_unused_fd(file_fd);
 141 fd_error:
 142         return ret;
 143 }
 144
 145 static
 146 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
 147 {
 148         v->major = LTTNG_MODULES_MAJOR_VERSION;
 149         v->minor = LTTNG_MODULES_MINOR_VERSION;
 150         v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
 151 }
 152
 153 static
 154 long lttng_abi_add_context(struct file *file,
 155         struct lttng_kernel_context *context_param,
 156         struct lttng_ctx **ctx, struct lttng_session *session)
 157 {
 158
 159         if (session->been_active)
 160                 return -EPERM;
 161
 162         switch (context_param->ctx) {
 163         case LTTNG_KERNEL_CONTEXT_PID:
 164                 return lttng_add_pid_to_ctx(ctx);
 165         case LTTNG_KERNEL_CONTEXT_PRIO:
 166                 return lttng_add_prio_to_ctx(ctx);
 167         case LTTNG_KERNEL_CONTEXT_NICE:
 168                 return lttng_add_nice_to_ctx(ctx);
 169         case LTTNG_KERNEL_CONTEXT_VPID:
 170                 return lttng_add_vpid_to_ctx(ctx);
 171         case LTTNG_KERNEL_CONTEXT_TID:
 172                 return lttng_add_tid_to_ctx(ctx);
 173         case LTTNG_KERNEL_CONTEXT_VTID:
 174                 return lttng_add_vtid_to_ctx(ctx);
 175         case LTTNG_KERNEL_CONTEXT_PPID:
 176                 return lttng_add_ppid_to_ctx(ctx);
 177         case LTTNG_KERNEL_CONTEXT_VPPID:
 178                 return lttng_add_vppid_to_ctx(ctx);
 179         case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
 180                 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 181                 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
 182                                 context_param->u.perf_counter.config,
 183                                 context_param->u.perf_counter.name,
 184                                 ctx);
 185         case LTTNG_KERNEL_CONTEXT_PROCNAME:
 186                 return lttng_add_procname_to_ctx(ctx);
 187         case LTTNG_KERNEL_CONTEXT_HOSTNAME:
 188                 return lttng_add_hostname_to_ctx(ctx);
 189         default:
 190                 return -EINVAL;
 191         }
 192 }
 193
 194 /**
 195  *      lttng_ioctl - lttng syscall through ioctl
 196  *
 197  *      @file: the file
 198  *      @cmd: the command
 199  *      @arg: command arg
 200  *
 201  *      This ioctl implements lttng commands:
 202  *      LTTNG_KERNEL_SESSION
 203  *              Returns a LTTng trace session file descriptor
 204  *      LTTNG_KERNEL_TRACER_VERSION
 205  *              Returns the LTTng kernel tracer version
 206  *      LTTNG_KERNEL_TRACEPOINT_LIST
 207  *              Returns a file descriptor listing available tracepoints
 208  *      LTTNG_KERNEL_WAIT_QUIESCENT
 209  *              Returns after all previously running probes have completed
 210  *
 211  * The returned session will be deleted when its file descriptor is closed.
 212  */
 213 static
 214 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 215 {
 216         switch (cmd) {
 217         case LTTNG_KERNEL_OLD_SESSION:
 218         case LTTNG_KERNEL_SESSION:
 219                 return lttng_abi_create_session();
 220         case LTTNG_KERNEL_OLD_TRACER_VERSION:
 221         {
 222                 struct lttng_kernel_tracer_version v;
 223                 struct lttng_kernel_old_tracer_version oldv;
 224                 struct lttng_kernel_old_tracer_version *uversion =
 225                         (struct lttng_kernel_old_tracer_version __user *) arg;
 226
 227                 lttng_abi_tracer_version(&v);
 228                 oldv.major = v.major;
 229                 oldv.minor = v.minor;
 230                 oldv.patchlevel = v.patchlevel;
 231
 232                 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
 233                         return -EFAULT;
 234                 return 0;
 235         }
 236         case LTTNG_KERNEL_TRACER_VERSION:
 237         {
 238                 struct lttng_kernel_tracer_version version;
 239                 struct lttng_kernel_tracer_version *uversion =
 240                         (struct lttng_kernel_tracer_version __user *) arg;
 241
 242                 lttng_abi_tracer_version(&version);
 243
 244                 if (copy_to_user(uversion, &version, sizeof(version)))
 245                         return -EFAULT;
 246                 return 0;
 247         }
 248         case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
 249         case LTTNG_KERNEL_TRACEPOINT_LIST:
 250                 return lttng_abi_tracepoint_list();
 251         case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
 252         case LTTNG_KERNEL_WAIT_QUIESCENT:
 253                 synchronize_trace();
 254                 return 0;
 255         case LTTNG_KERNEL_OLD_CALIBRATE:
 256         {
 257                 struct lttng_kernel_old_calibrate __user *ucalibrate =
 258                         (struct lttng_kernel_old_calibrate __user *) arg;
 259                 struct lttng_kernel_old_calibrate old_calibrate;
 260                 struct lttng_kernel_calibrate calibrate;
 261                 int ret;
 262
 263                 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
 264                         return -EFAULT;
 265                 calibrate.type = old_calibrate.type;
 266                 ret = lttng_calibrate(&calibrate);
 267                 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
 268                         return -EFAULT;
 269                 return ret;
 270         }
 271         case LTTNG_KERNEL_CALIBRATE:
 272         {
 273                 struct lttng_kernel_calibrate __user *ucalibrate =
 274                         (struct lttng_kernel_calibrate __user *) arg;
 275                 struct lttng_kernel_calibrate calibrate;
 276                 int ret;
 277
 278                 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
 279                         return -EFAULT;
 280                 ret = lttng_calibrate(&calibrate);
 281                 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
 282                         return -EFAULT;
 283                 return ret;
 284         }
 285         default:
 286                 return -ENOIOCTLCMD;
 287         }
 288 }
 289
 290 static const struct file_operations lttng_fops = {
 291         .owner = THIS_MODULE,
 292         .unlocked_ioctl = lttng_ioctl,
 293 #ifdef CONFIG_COMPAT
 294         .compat_ioctl = lttng_ioctl,
 295 #endif
 296 };
 297
 298 static
 299 int lttng_abi_create_channel(struct file *session_file,
 300                              struct lttng_kernel_channel *chan_param,
 301                              enum channel_type channel_type)
 302 {
 303         struct lttng_session *session = session_file->private_data;
 304         const struct file_operations *fops = NULL;
 305         const char *transport_name;
 306         struct lttng_channel *chan;
 307         struct file *chan_file;
 308         int chan_fd;
 309         int ret = 0;
 310
 311         chan_fd = get_unused_fd();
 312         if (chan_fd < 0) {
 313                 ret = chan_fd;
 314                 goto fd_error;
 315         }
 316         switch (channel_type) {
 317         case PER_CPU_CHANNEL:
 318                 fops = &lttng_channel_fops;
 319                 break;
 320         case METADATA_CHANNEL:
 321                 fops = &lttng_metadata_fops;
 322                 break;
 323         }
 324
 325         chan_file = anon_inode_getfile("[lttng_channel]",
 326                                        fops,
 327                                        NULL, O_RDWR);
 328         if (IS_ERR(chan_file)) {
 329                 ret = PTR_ERR(chan_file);
 330                 goto file_error;
 331         }
 332         switch (channel_type) {
 333         case PER_CPU_CHANNEL:
 334                 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
 335                         transport_name = chan_param->overwrite ?
 336                                 "relay-overwrite" : "relay-discard";
 337                 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
 338                         transport_name = chan_param->overwrite ?
 339                                 "relay-overwrite-mmap" : "relay-discard-mmap";
 340                 } else {
 341                         return -EINVAL;
 342                 }
 343                 break;
 344         case METADATA_CHANNEL:
 345                 if (chan_param->output == LTTNG_KERNEL_SPLICE)
 346                         transport_name = "relay-metadata";
 347                 else if (chan_param->output == LTTNG_KERNEL_MMAP)
 348                         transport_name = "relay-metadata-mmap";
 349                 else
 350                         return -EINVAL;
 351                 break;
 352         default:
 353                 transport_name = "<unknown>";
 354                 break;
 355         }
 356         /*
 357          * We tolerate no failure path after channel creation. It will stay
 358          * invariant for the rest of the session.
 359          */
 360         chan = lttng_channel_create(session, transport_name, NULL,
 361                                   chan_param->subbuf_size,
 362                                   chan_param->num_subbuf,
 363                                   chan_param->switch_timer_interval,
 364                                   chan_param->read_timer_interval,
 365                                   channel_type);
 366         if (!chan) {
 367                 ret = -EINVAL;
 368                 goto chan_error;
 369         }
 370         chan->file = chan_file;
 371         chan_file->private_data = chan;
 372         fd_install(chan_fd, chan_file);
 373         atomic_long_inc(&session_file->f_count);
 374
 375         return chan_fd;
 376
 377 chan_error:
 378         fput(chan_file);
 379 file_error:
 380         put_unused_fd(chan_fd);
 381 fd_error:
 382         return ret;
 383 }
 384
 385 /**
 386  *      lttng_session_ioctl - lttng session fd ioctl
 387  *
 388  *      @file: the file
 389  *      @cmd: the command
 390  *      @arg: command arg
 391  *
 392  *      This ioctl implements lttng commands:
 393  *      LTTNG_KERNEL_CHANNEL
 394  *              Returns a LTTng channel file descriptor
 395  *      LTTNG_KERNEL_ENABLE
 396  *              Enables tracing for a session (weak enable)
 397  *      LTTNG_KERNEL_DISABLE
 398  *              Disables tracing for a session (strong disable)
 399  *      LTTNG_KERNEL_METADATA
 400  *              Returns a LTTng metadata file descriptor
 401  *
 402  * The returned channel will be deleted when its file descriptor is closed.
 403  */
 404 static
 405 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 406 {
 407         struct lttng_session *session = file->private_data;
 408
 409         switch (cmd) {
 410         case LTTNG_KERNEL_OLD_CHANNEL:
 411         {
 412                 struct lttng_kernel_channel chan_param;
 413                 struct lttng_kernel_old_channel old_chan_param;
 414
 415                 if (copy_from_user(&old_chan_param,
 416                                 (struct lttng_kernel_old_channel __user *) arg,
 417                                 sizeof(struct lttng_kernel_old_channel)))
 418                         return -EFAULT;
 419                 chan_param.overwrite = old_chan_param.overwrite;
 420                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 421                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 422                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 423                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 424                 chan_param.output = old_chan_param.output;
 425
 426                 return lttng_abi_create_channel(file, &chan_param,
 427                                 PER_CPU_CHANNEL);
 428         }
 429         case LTTNG_KERNEL_CHANNEL:
 430         {
 431                 struct lttng_kernel_channel chan_param;
 432
 433                 if (copy_from_user(&chan_param,
 434                                 (struct lttng_kernel_channel __user *) arg,
 435                                 sizeof(struct lttng_kernel_channel)))
 436                         return -EFAULT;
 437                 return lttng_abi_create_channel(file, &chan_param,
 438                                 PER_CPU_CHANNEL);
 439         }
 440         case LTTNG_KERNEL_OLD_SESSION_START:
 441         case LTTNG_KERNEL_OLD_ENABLE:
 442         case LTTNG_KERNEL_SESSION_START:
 443         case LTTNG_KERNEL_ENABLE:
 444                 return lttng_session_enable(session);
 445         case LTTNG_KERNEL_OLD_SESSION_STOP:
 446         case LTTNG_KERNEL_OLD_DISABLE:
 447         case LTTNG_KERNEL_SESSION_STOP:
 448         case LTTNG_KERNEL_DISABLE:
 449                 return lttng_session_disable(session);
 450         case LTTNG_KERNEL_OLD_METADATA:
 451         {
 452                 struct lttng_kernel_channel chan_param;
 453                 struct lttng_kernel_old_channel old_chan_param;
 454
 455                 if (copy_from_user(&old_chan_param,
 456                                 (struct lttng_kernel_old_channel __user *) arg,
 457                                 sizeof(struct lttng_kernel_old_channel)))
 458                         return -EFAULT;
 459                 chan_param.overwrite = old_chan_param.overwrite;
 460                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 461                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 462                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 463                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 464                 chan_param.output = old_chan_param.output;
 465
 466                 return lttng_abi_create_channel(file, &chan_param,
 467                                 METADATA_CHANNEL);
 468         }
 469         case LTTNG_KERNEL_METADATA:
 470         {
 471                 struct lttng_kernel_channel chan_param;
 472
 473                 if (copy_from_user(&chan_param,
 474                                         (struct lttng_kernel_channel __user *) arg,
 475                                         sizeof(struct lttng_kernel_channel)))
 476                         return -EFAULT;
 477                 return lttng_abi_create_channel(file, &chan_param,
 478                                 METADATA_CHANNEL);
 479         }
 480         default:
 481                 return -ENOIOCTLCMD;
 482         }
 483 }
 484
 485 /*
 486  * Called when the last file reference is dropped.
 487  *
 488  * Big fat note: channels and events are invariant for the whole session after
 489  * their creation. So this session destruction also destroys all channel and
 490  * event structures specific to this session (they are not destroyed when their
 491  * individual file is released).
 492  */
 493 static
 494 int lttng_session_release(struct inode *inode, struct file *file)
 495 {
 496         struct lttng_session *session = file->private_data;
 497
 498         if (session)
 499                 lttng_session_destroy(session);
 500         return 0;
 501 }
 502
 503 static const struct file_operations lttng_session_fops = {
 504         .owner = THIS_MODULE,
 505         .release = lttng_session_release,
 506         .unlocked_ioctl = lttng_session_ioctl,
 507 #ifdef CONFIG_COMPAT
 508         .compat_ioctl = lttng_session_ioctl,
 509 #endif
 510 };
 511
 512 /**
 513  *      lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
 514  *      @filp: the file
 515  *      @wait: poll table
 516  *
 517  *      Handles the poll operations for the metadata channels.
 518  */
 519 static
 520 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 521                 poll_table *wait)
 522 {
 523         struct lttng_metadata_stream *stream = filp->private_data;
 524         struct lib_ring_buffer *buf = stream->priv;
 525         int finalized;
 526         unsigned int mask = 0;
 527
 528         if (filp->f_mode & FMODE_READ) {
 529                 poll_wait_set_exclusive(wait);
 530                 poll_wait(filp, &stream->read_wait, wait);
 531
 532                 finalized = stream->finalized;
 533
 534                 /*
 535                  * lib_ring_buffer_is_finalized() contains a smp_rmb()
 536                  * ordering finalized load before offsets loads.
 537                  */
 538                 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
 539
 540                 if (finalized)
 541                         mask |= POLLHUP;
 542
 543                 if (stream->metadata_cache->metadata_written >
 544                                 stream->metadata_out)
 545                         mask |= POLLIN;
 546         }
 547
 548         return mask;
 549 }
 550
 551 static
 552 int lttng_metadata_ring_buffer_ioctl_get_next_subbuf(struct file *filp,
 553                 unsigned int cmd, unsigned long arg)
 554 {
 555         struct lttng_metadata_stream *stream = filp->private_data;
 556         struct lib_ring_buffer *buf = stream->priv;
 557         struct channel *chan = buf->backend.chan;
 558         int ret;
 559
 560         ret = lttng_metadata_output_channel(stream, chan);
 561         if (ret > 0) {
 562                 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 563                 ret = 0;
 564         }
 565         return ret;
 566 }
 567
 568 static
 569 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 570                 unsigned int cmd, unsigned long arg)
 571 {
 572         struct lttng_metadata_stream *stream = filp->private_data;
 573
 574         stream->metadata_out = stream->metadata_in;
 575 }
 576
 577 static
 578 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 579                 unsigned int cmd, unsigned long arg)
 580 {
 581         int ret;
 582         struct lttng_metadata_stream *stream = filp->private_data;
 583         struct lib_ring_buffer *buf = stream->priv;
 584
 585         switch (cmd) {
 586         case RING_BUFFER_GET_NEXT_SUBBUF:
 587         {
 588                 ret = lttng_metadata_ring_buffer_ioctl_get_next_subbuf(filp,
 589                                 cmd, arg);
 590                 if (ret < 0)
 591                         goto err;
 592                 break;
 593         }
 594         case RING_BUFFER_GET_SUBBUF:
 595         {
 596                 /*
 597                  * Random access is not allowed for metadata channel.
 598                  */
 599                 return -ENOSYS;
 600         }
 601         default:
 602                 break;
 603         }
 604         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 605
 606         /* Performing lib ring buffer ioctl after our own. */
 607         ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
 608         if (ret < 0)
 609                 goto err;
 610
 611         switch (cmd) {
 612         case RING_BUFFER_PUT_NEXT_SUBBUF:
 613         {
 614                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 615                                 cmd, arg);
 616                 break;
 617         }
 618         default:
 619                 break;
 620         }
 621 err:
 622         return ret;
 623 }
 624
 625 #ifdef CONFIG_COMPAT
 626 static
 627 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 628                 unsigned int cmd, unsigned long arg)
 629 {
 630         int ret;
 631         struct lttng_metadata_stream *stream = filp->private_data;
 632         struct lib_ring_buffer *buf = stream->priv;
 633
 634         switch (cmd) {
 635         case RING_BUFFER_GET_NEXT_SUBBUF:
 636         {
 637                 ret = lttng_metadata_ring_buffer_ioctl_get_next_subbuf(filp,
 638                                 cmd, arg);
 639                 if (ret < 0)
 640                         goto err;
 641                 break;
 642         }
 643         case RING_BUFFER_GET_SUBBUF:
 644         {
 645                 /*
 646                  * Random access is not allowed for metadata channel.
 647                  */
 648                 return -ENOSYS;
 649         }
 650         default:
 651                 break;
 652         }
 653         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 654
 655         /* Performing lib ring buffer ioctl after our own. */
 656         ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
 657         if (ret < 0)
 658                 goto err;
 659
 660         switch (cmd) {
 661         case RING_BUFFER_PUT_NEXT_SUBBUF:
 662         {
 663                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 664                                 cmd, arg);
 665                 break;
 666         }
 667         default:
 668                 break;
 669         }
 670 err:
 671         return ret;
 672 }
 673 #endif
 674
 675 /*
 676  * This is not used by anonymous file descriptors. This code is left
 677  * there if we ever want to implement an inode with open() operation.
 678  */
 679 static
 680 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 681 {
 682         struct lttng_metadata_stream *stream = inode->i_private;
 683         struct lib_ring_buffer *buf = stream->priv;
 684
 685         file->private_data = buf;
 686         /*
 687          * Since life-time of metadata cache differs from that of
 688          * session, we need to keep our own reference on the transport.
 689          */
 690         if (!try_module_get(stream->transport->owner)) {
 691                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 692                 return -EBUSY;
 693         }
 694         return lib_ring_buffer_open(inode, file, buf);
 695 }
 696
 697 static
 698 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
 699 {
 700         struct lttng_metadata_stream *stream = file->private_data;
 701         struct lib_ring_buffer *buf = stream->priv;
 702
 703         kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
 704         module_put(stream->transport->owner);
 705         return lib_ring_buffer_release(inode, file, buf);
 706 }
 707
 708 static
 709 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 710                 struct pipe_inode_info *pipe, size_t len,
 711                 unsigned int flags)
 712 {
 713         struct lttng_metadata_stream *stream = in->private_data;
 714         struct lib_ring_buffer *buf = stream->priv;
 715
 716         return lib_ring_buffer_splice_read(in, ppos, pipe, len,
 717                         flags, buf);
 718 }
 719
 720 static
 721 int lttng_metadata_ring_buffer_mmap(struct file *filp,
 722                 struct vm_area_struct *vma)
 723 {
 724         struct lttng_metadata_stream *stream = filp->private_data;
 725         struct lib_ring_buffer *buf = stream->priv;
 726
 727         return lib_ring_buffer_mmap(filp, vma, buf);
 728 }
 729
 730 static
 731 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
 732         .owner = THIS_MODULE,
 733         .open = lttng_metadata_ring_buffer_open,
 734         .release = lttng_metadata_ring_buffer_release,
 735         .poll = lttng_metadata_ring_buffer_poll,
 736         .splice_read = lttng_metadata_ring_buffer_splice_read,
 737         .mmap = lttng_metadata_ring_buffer_mmap,
 738         .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
 739         .llseek = vfs_lib_ring_buffer_no_llseek,
 740 #ifdef CONFIG_COMPAT
 741         .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
 742 #endif
 743 };
 744
 745 static
 746 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
 747                 const struct file_operations *fops)
 748 {
 749         int stream_fd, ret;
 750         struct file *stream_file;
 751
 752         stream_fd = get_unused_fd();
 753         if (stream_fd < 0) {
 754                 ret = stream_fd;
 755                 goto fd_error;
 756         }
 757         stream_file = anon_inode_getfile("[lttng_stream]", fops,
 758                         stream_priv, O_RDWR);
 759         if (IS_ERR(stream_file)) {
 760                 ret = PTR_ERR(stream_file);
 761                 goto file_error;
 762         }
 763         /*
 764          * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
 765          * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
 766          * file descriptor, so we set FMODE_PREAD here.
 767          */
 768         stream_file->f_mode |= FMODE_PREAD;
 769         fd_install(stream_fd, stream_file);
 770         /*
 771          * The stream holds a reference to the channel within the generic ring
 772          * buffer library, so no need to hold a refcount on the channel and
 773          * session files here.
 774          */
 775         return stream_fd;
 776
 777 file_error:
 778         put_unused_fd(stream_fd);
 779 fd_error:
 780         return ret;
 781 }
 782
 783 static
 784 int lttng_abi_open_stream(struct file *channel_file)
 785 {
 786         struct lttng_channel *channel = channel_file->private_data;
 787         struct lib_ring_buffer *buf;
 788         int ret;
 789         void *stream_priv;
 790
 791         buf = channel->ops->buffer_read_open(channel->chan);
 792         if (!buf)
 793                 return -ENOENT;
 794
 795         stream_priv = buf;
 796         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 797                         &lttng_stream_ring_buffer_file_operations);
 798         if (ret < 0)
 799                 goto fd_error;
 800
 801         return ret;
 802
 803 fd_error:
 804         channel->ops->buffer_read_close(buf);
 805         return ret;
 806 }
 807
 808 static
 809 int lttng_abi_open_metadata_stream(struct file *channel_file)
 810 {
 811         struct lttng_channel *channel = channel_file->private_data;
 812         struct lttng_session *session = channel->session;
 813         struct lib_ring_buffer *buf;
 814         int ret;
 815         struct lttng_metadata_stream *metadata_stream;
 816         void *stream_priv;
 817
 818         buf = channel->ops->buffer_read_open(channel->chan);
 819         if (!buf)
 820                 return -ENOENT;
 821
 822         metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
 823                         GFP_KERNEL);
 824         if (!metadata_stream) {
 825                 ret = -ENOMEM;
 826                 goto nomem;
 827         }
 828         metadata_stream->metadata_cache = session->metadata_cache;
 829         init_waitqueue_head(&metadata_stream->read_wait);
 830         metadata_stream->priv = buf;
 831         stream_priv = metadata_stream;
 832         metadata_stream->transport = channel->transport;
 833
 834         /*
 835          * Since life-time of metadata cache differs from that of
 836          * session, we need to keep our own reference on the transport.
 837          */
 838         if (!try_module_get(metadata_stream->transport->owner)) {
 839                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 840                 ret = -EINVAL;
 841                 goto notransport;
 842         }
 843
 844         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 845                         &lttng_metadata_ring_buffer_file_operations);
 846         if (ret < 0)
 847                 goto fd_error;
 848
 849         kref_get(&session->metadata_cache->refcount);
 850         list_add(&metadata_stream->list,
 851                 &session->metadata_cache->metadata_stream);
 852         return ret;
 853
 854 fd_error:
 855         module_put(metadata_stream->transport->owner);
 856 notransport:
 857         kfree(metadata_stream);
 858 nomem:
 859         channel->ops->buffer_read_close(buf);
 860         return ret;
 861 }
 862
 863 static
 864 int lttng_abi_create_event(struct file *channel_file,
 865                            struct lttng_kernel_event *event_param)
 866 {
 867         struct lttng_channel *channel = channel_file->private_data;
 868         struct lttng_event *event;
 869         int event_fd, ret;
 870         struct file *event_file;
 871
 872         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 873         switch (event_param->instrumentation) {
 874         case LTTNG_KERNEL_KRETPROBE:
 875                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 876                 break;
 877         case LTTNG_KERNEL_KPROBE:
 878                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 879                 break;
 880         case LTTNG_KERNEL_FUNCTION:
 881                 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 882                 break;
 883         default:
 884                 break;
 885         }
 886         switch (event_param->instrumentation) {
 887         default:
 888                 event_fd = get_unused_fd();
 889                 if (event_fd < 0) {
 890                         ret = event_fd;
 891                         goto fd_error;
 892                 }
 893                 event_file = anon_inode_getfile("[lttng_event]",
 894                                                 &lttng_event_fops,
 895                                                 NULL, O_RDWR);
 896                 if (IS_ERR(event_file)) {
 897                         ret = PTR_ERR(event_file);
 898                         goto file_error;
 899                 }
 900                 /*
 901                  * We tolerate no failure path after event creation. It
 902                  * will stay invariant for the rest of the session.
 903                  */
 904                 event = lttng_event_create(channel, event_param, NULL, NULL);
 905                 if (!event) {
 906                         ret = -EINVAL;
 907                         goto event_error;
 908                 }
 909                 event_file->private_data = event;
 910                 fd_install(event_fd, event_file);
 911                 /* The event holds a reference on the channel */
 912                 atomic_long_inc(&channel_file->f_count);
 913                 break;
 914         case LTTNG_KERNEL_SYSCALL:
 915                 /*
 916                  * Only all-syscall tracing supported for now.
 917                  */
 918                 if (event_param->name[0] != '\0')
 919                         return -EINVAL;
 920                 ret = lttng_syscalls_register(channel, NULL);
 921                 if (ret)
 922                         goto fd_error;
 923                 event_fd = 0;
 924                 break;
 925         }
 926         return event_fd;
 927
 928 event_error:
 929         fput(event_file);
 930 file_error:
 931         put_unused_fd(event_fd);
 932 fd_error:
 933         return ret;
 934 }
 935
 936 /**
 937  *      lttng_channel_ioctl - lttng syscall through ioctl
 938  *
 939  *      @file: the file
 940  *      @cmd: the command
 941  *      @arg: command arg
 942  *
 943  *      This ioctl implements lttng commands:
 944  *      LTTNG_KERNEL_STREAM
 945  *              Returns an event stream file descriptor or failure.
 946  *              (typically, one event stream records events from one CPU)
 947  *      LTTNG_KERNEL_EVENT
 948  *              Returns an event file descriptor or failure.
 949  *      LTTNG_KERNEL_CONTEXT
 950  *              Prepend a context field to each event in the channel
 951  *      LTTNG_KERNEL_ENABLE
 952  *              Enable recording for events in this channel (weak enable)
 953  *      LTTNG_KERNEL_DISABLE
 954  *              Disable recording for events in this channel (strong disable)
 955  *
 956  * Channel and event file descriptors also hold a reference on the session.
 957  */
 958 static
 959 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 960 {
 961         struct lttng_channel *channel = file->private_data;
 962
 963         switch (cmd) {
 964         case LTTNG_KERNEL_OLD_STREAM:
 965         case LTTNG_KERNEL_STREAM:
 966                 return lttng_abi_open_stream(file);
 967         case LTTNG_KERNEL_OLD_EVENT:
 968         {
 969                 struct lttng_kernel_event *uevent_param;
 970                 struct lttng_kernel_old_event *old_uevent_param;
 971                 int ret;
 972
 973                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
 974                                 GFP_KERNEL);
 975                 if (!uevent_param) {
 976                         ret = -ENOMEM;
 977                         goto old_event_end;
 978                 }
 979                 old_uevent_param = kmalloc(
 980                                 sizeof(struct lttng_kernel_old_event),
 981                                 GFP_KERNEL);
 982                 if (!old_uevent_param) {
 983                         ret = -ENOMEM;
 984                         goto old_event_error_free_param;
 985                 }
 986                 if (copy_from_user(old_uevent_param,
 987                                 (struct lttng_kernel_old_event __user *) arg,
 988                                 sizeof(struct lttng_kernel_old_event))) {
 989                         ret = -EFAULT;
 990                         goto old_event_error_free_old_param;
 991                 }
 992
 993                 memcpy(uevent_param->name, old_uevent_param->name,
 994                                 sizeof(uevent_param->name));
 995                 uevent_param->instrumentation =
 996                         old_uevent_param->instrumentation;
 997
 998                 switch (old_uevent_param->instrumentation) {
 999                 case LTTNG_KERNEL_KPROBE:
1000                         uevent_param->u.kprobe.addr =
1001                                 old_uevent_param->u.kprobe.addr;
1002                         uevent_param->u.kprobe.offset =
1003                                 old_uevent_param->u.kprobe.offset;
1004                         memcpy(uevent_param->u.kprobe.symbol_name,
1005                                 old_uevent_param->u.kprobe.symbol_name,
1006                                 sizeof(uevent_param->u.kprobe.symbol_name));
1007                         break;
1008                 case LTTNG_KERNEL_KRETPROBE:
1009                         uevent_param->u.kretprobe.addr =
1010                                 old_uevent_param->u.kretprobe.addr;
1011                         uevent_param->u.kretprobe.offset =
1012                                 old_uevent_param->u.kretprobe.offset;
1013                         memcpy(uevent_param->u.kretprobe.symbol_name,
1014                                 old_uevent_param->u.kretprobe.symbol_name,
1015                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1016                         break;
1017                 case LTTNG_KERNEL_FUNCTION:
1018                         memcpy(uevent_param->u.ftrace.symbol_name,
1019                                         old_uevent_param->u.ftrace.symbol_name,
1020                                         sizeof(uevent_param->u.ftrace.symbol_name));
1021                         break;
1022                 default:
1023                         break;
1024                 }
1025                 ret = lttng_abi_create_event(file, uevent_param);
1026
1027 old_event_error_free_old_param:
1028                 kfree(old_uevent_param);
1029 old_event_error_free_param:
1030                 kfree(uevent_param);
1031 old_event_end:
1032                 return ret;
1033         }
1034         case LTTNG_KERNEL_EVENT:
1035         {
1036                 struct lttng_kernel_event uevent_param;
1037
1038                 if (copy_from_user(&uevent_param,
1039                                 (struct lttng_kernel_event __user *) arg,
1040                                 sizeof(uevent_param)))
1041                         return -EFAULT;
1042                 return lttng_abi_create_event(file, &uevent_param);
1043         }
1044         case LTTNG_KERNEL_OLD_CONTEXT:
1045         {
1046                 struct lttng_kernel_context *ucontext_param;
1047                 struct lttng_kernel_old_context *old_ucontext_param;
1048                 int ret;
1049
1050                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1051                                 GFP_KERNEL);
1052                 if (!ucontext_param) {
1053                         ret = -ENOMEM;
1054                         goto old_ctx_end;
1055                 }
1056                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1057                                 GFP_KERNEL);
1058                 if (!old_ucontext_param) {
1059                         ret = -ENOMEM;
1060                         goto old_ctx_error_free_param;
1061                 }
1062
1063                 if (copy_from_user(old_ucontext_param,
1064                                 (struct lttng_kernel_old_context __user *) arg,
1065                                 sizeof(struct lttng_kernel_old_context))) {
1066                         ret = -EFAULT;
1067                         goto old_ctx_error_free_old_param;
1068                 }
1069                 ucontext_param->ctx = old_ucontext_param->ctx;
1070                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1071                                 sizeof(ucontext_param->padding));
1072                 /* only type that uses the union */
1073                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1074                         ucontext_param->u.perf_counter.type =
1075                                 old_ucontext_param->u.perf_counter.type;
1076                         ucontext_param->u.perf_counter.config =
1077                                 old_ucontext_param->u.perf_counter.config;
1078                         memcpy(ucontext_param->u.perf_counter.name,
1079                                 old_ucontext_param->u.perf_counter.name,
1080                                 sizeof(ucontext_param->u.perf_counter.name));
1081                 }
1082
1083                 ret = lttng_abi_add_context(file,
1084                                 ucontext_param,
1085                                 &channel->ctx, channel->session);
1086
1087 old_ctx_error_free_old_param:
1088                 kfree(old_ucontext_param);
1089 old_ctx_error_free_param:
1090                 kfree(ucontext_param);
1091 old_ctx_end:
1092                 return ret;
1093         }
1094         case LTTNG_KERNEL_CONTEXT:
1095         {
1096                 struct lttng_kernel_context ucontext_param;
1097
1098                 if (copy_from_user(&ucontext_param,
1099                                 (struct lttng_kernel_context __user *) arg,
1100                                 sizeof(ucontext_param)))
1101                         return -EFAULT;
1102                 return lttng_abi_add_context(file,
1103                                 &ucontext_param,
1104                                 &channel->ctx, channel->session);
1105         }
1106         case LTTNG_KERNEL_OLD_ENABLE:
1107         case LTTNG_KERNEL_ENABLE:
1108                 return lttng_channel_enable(channel);
1109         case LTTNG_KERNEL_OLD_DISABLE:
1110         case LTTNG_KERNEL_DISABLE:
1111                 return lttng_channel_disable(channel);
1112         default:
1113                 return -ENOIOCTLCMD;
1114         }
1115
1116 }
1117
1118 /**
1119  *      lttng_metadata_ioctl - lttng syscall through ioctl
1120  *
1121  *      @file: the file
1122  *      @cmd: the command
1123  *      @arg: command arg
1124  *
1125  *      This ioctl implements lttng commands:
1126  *      LTTNG_KERNEL_STREAM
1127  *              Returns an event stream file descriptor or failure.
1128  *
1129  * Channel and event file descriptors also hold a reference on the session.
1130  */
1131 static
1132 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1133 {
1134         switch (cmd) {
1135         case LTTNG_KERNEL_OLD_STREAM:
1136         case LTTNG_KERNEL_STREAM:
1137                 return lttng_abi_open_metadata_stream(file);
1138         default:
1139                 return -ENOIOCTLCMD;
1140         }
1141 }
1142
1143 /**
1144  *      lttng_channel_poll - lttng stream addition/removal monitoring
1145  *
1146  *      @file: the file
1147  *      @wait: poll table
1148  */
1149 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1150 {
1151         struct lttng_channel *channel = file->private_data;
1152         unsigned int mask = 0;
1153
1154         if (file->f_mode & FMODE_READ) {
1155                 poll_wait_set_exclusive(wait);
1156                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1157                           wait);
1158
1159                 if (channel->ops->is_disabled(channel->chan))
1160                         return POLLERR;
1161                 if (channel->ops->is_finalized(channel->chan))
1162                         return POLLHUP;
1163                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1164                         return POLLIN | POLLRDNORM;
1165                 return 0;
1166         }
1167         return mask;
1168
1169 }
1170
1171 static
1172 int lttng_channel_release(struct inode *inode, struct file *file)
1173 {
1174         struct lttng_channel *channel = file->private_data;
1175
1176         if (channel)
1177                 fput(channel->session->file);
1178         return 0;
1179 }
1180
1181 static
1182 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1183 {
1184         struct lttng_channel *channel = file->private_data;
1185
1186         if (channel) {
1187                 lttng_metadata_channel_destroy(channel);
1188                 fput(channel->session->file);
1189         }
1190
1191         return 0;
1192 }
1193
1194 static const struct file_operations lttng_channel_fops = {
1195         .owner = THIS_MODULE,
1196         .release = lttng_channel_release,
1197         .poll = lttng_channel_poll,
1198         .unlocked_ioctl = lttng_channel_ioctl,
1199 #ifdef CONFIG_COMPAT
1200         .compat_ioctl = lttng_channel_ioctl,
1201 #endif
1202 };
1203
1204 static const struct file_operations lttng_metadata_fops = {
1205         .owner = THIS_MODULE,
1206         .release = lttng_metadata_channel_release,
1207         .unlocked_ioctl = lttng_metadata_ioctl,
1208 #ifdef CONFIG_COMPAT
1209         .compat_ioctl = lttng_metadata_ioctl,
1210 #endif
1211 };
1212
1213 /**
1214  *      lttng_event_ioctl - lttng syscall through ioctl
1215  *
1216  *      @file: the file
1217  *      @cmd: the command
1218  *      @arg: command arg
1219  *
1220  *      This ioctl implements lttng commands:
1221  *      LTTNG_KERNEL_CONTEXT
1222  *              Prepend a context field to each record of this event
1223  *      LTTNG_KERNEL_ENABLE
1224  *              Enable recording for this event (weak enable)
1225  *      LTTNG_KERNEL_DISABLE
1226  *              Disable recording for this event (strong disable)
1227  */
1228 static
1229 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1230 {
1231         struct lttng_event *event = file->private_data;
1232
1233         switch (cmd) {
1234         case LTTNG_KERNEL_OLD_CONTEXT:
1235         {
1236                 struct lttng_kernel_context *ucontext_param;
1237                 struct lttng_kernel_old_context *old_ucontext_param;
1238                 int ret;
1239
1240                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1241                                 GFP_KERNEL);
1242                 if (!ucontext_param) {
1243                         ret = -ENOMEM;
1244                         goto old_ctx_end;
1245                 }
1246                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1247                                 GFP_KERNEL);
1248                 if (!old_ucontext_param) {
1249                         ret = -ENOMEM;
1250                         goto old_ctx_error_free_param;
1251                 }
1252
1253                 if (copy_from_user(old_ucontext_param,
1254                                         (struct lttng_kernel_old_context __user *) arg,
1255                                         sizeof(struct lttng_kernel_old_context))) {
1256                         ret = -EFAULT;
1257                         goto old_ctx_error_free_old_param;
1258                 }
1259                 ucontext_param->ctx = old_ucontext_param->ctx;
1260                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1261                                 sizeof(ucontext_param->padding));
1262                 /* only type that uses the union */
1263                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1264                         ucontext_param->u.perf_counter.type =
1265                                 old_ucontext_param->u.perf_counter.type;
1266                         ucontext_param->u.perf_counter.config =
1267                                 old_ucontext_param->u.perf_counter.config;
1268                         memcpy(ucontext_param->u.perf_counter.name,
1269                                         old_ucontext_param->u.perf_counter.name,
1270                                         sizeof(ucontext_param->u.perf_counter.name));
1271                 }
1272
1273                 ret = lttng_abi_add_context(file,
1274                                 ucontext_param,
1275                                 &event->ctx, event->chan->session);
1276
1277 old_ctx_error_free_old_param:
1278                 kfree(old_ucontext_param);
1279 old_ctx_error_free_param:
1280                 kfree(ucontext_param);
1281 old_ctx_end:
1282                 return ret;
1283         }
1284         case LTTNG_KERNEL_CONTEXT:
1285         {
1286                 struct lttng_kernel_context ucontext_param;
1287
1288                 if (copy_from_user(&ucontext_param,
1289                                         (struct lttng_kernel_context __user *) arg,
1290                                         sizeof(ucontext_param)))
1291                         return -EFAULT;
1292                 return lttng_abi_add_context(file,
1293                                 &ucontext_param,
1294                                 &event->ctx, event->chan->session);
1295         }
1296         case LTTNG_KERNEL_OLD_ENABLE:
1297         case LTTNG_KERNEL_ENABLE:
1298                 return lttng_event_enable(event);
1299         case LTTNG_KERNEL_OLD_DISABLE:
1300         case LTTNG_KERNEL_DISABLE:
1301                 return lttng_event_disable(event);
1302         default:
1303                 return -ENOIOCTLCMD;
1304         }
1305 }
1306
1307 static
1308 int lttng_event_release(struct inode *inode, struct file *file)
1309 {
1310         struct lttng_event *event = file->private_data;
1311
1312         if (event)
1313                 fput(event->chan->file);
1314         return 0;
1315 }
1316
1317 /* TODO: filter control ioctl */
1318 static const struct file_operations lttng_event_fops = {
1319         .owner = THIS_MODULE,
1320         .release = lttng_event_release,
1321         .unlocked_ioctl = lttng_event_ioctl,
1322 #ifdef CONFIG_COMPAT
1323         .compat_ioctl = lttng_event_ioctl,
1324 #endif
1325 };
1326
1327 static int put_u64(uint64_t val, unsigned long arg)
1328 {
1329         return put_user(val, (uint64_t __user *) arg);
1330 }
1331
1332 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1333                 unsigned int cmd, unsigned long arg)
1334 {
1335         struct lib_ring_buffer *buf = filp->private_data;
1336         struct channel *chan = buf->backend.chan;
1337         const struct lib_ring_buffer_config *config = &chan->backend.config;
1338         struct lttng_channel *lttng_chan = channel_get_private(chan);
1339         int ret;
1340
1341         if (atomic_read(&chan->record_disabled))
1342                 return -EIO;
1343
1344         switch (cmd) {
1345         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1346         {
1347                 uint64_t ts;
1348
1349                 if (!lttng_chan->ops)
1350                         goto error;
1351                 ret = lttng_chan->ops->timestamp_begin(config, buf, &ts);
1352                 if (ret < 0)
1353                         goto error;
1354                 return put_u64(ts, arg);
1355         }
1356         case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1357         {
1358                 uint64_t ts;
1359
1360                 if (!lttng_chan->ops)
1361                         goto error;
1362                 ret = lttng_chan->ops->timestamp_end(config, buf, &ts);
1363                 if (ret < 0)
1364                         goto error;
1365                 return put_u64(ts, arg);
1366         }
1367         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1368         {
1369                 uint64_t ed;
1370
1371                 if (!lttng_chan->ops)
1372                         goto error;
1373                 ret = lttng_chan->ops->events_discarded(config, buf, &ed);
1374                 if (ret < 0)
1375                         goto error;
1376                 return put_u64(ed, arg);
1377         }
1378         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1379         {
1380                 uint64_t cs;
1381
1382                 if (!lttng_chan->ops)
1383                         goto error;
1384                 ret = lttng_chan->ops->content_size(config, buf, &cs);
1385                 if (ret < 0)
1386                         goto error;
1387                 return put_u64(cs, arg);
1388         }
1389         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1390         {
1391                 uint64_t ps;
1392
1393                 if (!lttng_chan->ops)
1394                         goto error;
1395                 ret = lttng_chan->ops->packet_size(config, buf, &ps);
1396                 if (ret < 0)
1397                         goto error;
1398                 return put_u64(ps, arg);
1399         }
1400         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1401         {
1402                 uint64_t si;
1403
1404                 if (!lttng_chan->ops)
1405                         goto error;
1406                 ret = lttng_chan->ops->stream_id(config, buf, &si);
1407                 if (ret < 0)
1408                         goto error;
1409                 return put_u64(si, arg);
1410         }
1411         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1412         {
1413                 uint64_t ts;
1414
1415                 if (!lttng_chan->ops)
1416                         goto error;
1417                 ret = lttng_chan->ops->current_timestamp(config, buf, &ts);
1418                 if (ret < 0)
1419                         goto error;
1420                 return put_u64(ts, arg);
1421         }
1422         default:
1423                 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1424                                 cmd, arg);
1425         }
1426
1427 error:
1428         return -ENOSYS;
1429 }
1430
1431 #ifdef CONFIG_COMPAT
1432 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1433                 unsigned int cmd, unsigned long arg)
1434 {
1435         struct lib_ring_buffer *buf = filp->private_data;
1436         struct channel *chan = buf->backend.chan;
1437         const struct lib_ring_buffer_config *config = &chan->backend.config;
1438         struct lttng_channel *lttng_chan = channel_get_private(chan);
1439         int ret;
1440
1441         if (atomic_read(&chan->record_disabled))
1442                 return -EIO;
1443
1444         switch (cmd) {
1445         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1446         {
1447                 uint64_t ts;
1448
1449                 if (!lttng_chan->ops)
1450                         goto error;
1451                 ret = lttng_chan->ops->timestamp_begin(config, buf, &ts);
1452                 if (ret < 0)
1453                         goto error;
1454                 return put_u64(ts, arg);
1455         }
1456         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1457         {
1458                 uint64_t ts;
1459
1460                 if (!lttng_chan->ops)
1461                         goto error;
1462                 ret = lttng_chan->ops->timestamp_end(config, buf, &ts);
1463                 if (ret < 0)
1464                         goto error;
1465                 return put_u64(ts, arg);
1466         }
1467         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1468         {
1469                 uint64_t ed;
1470
1471                 if (!lttng_chan->ops)
1472                         goto error;
1473                 ret = lttng_chan->ops->events_discarded(config, buf, &ed);
1474                 if (ret < 0)
1475                         goto error;
1476                 return put_u64(ed, arg);
1477         }
1478         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1479         {
1480                 uint64_t cs;
1481
1482                 if (!lttng_chan->ops)
1483                         goto error;
1484                 ret = lttng_chan->ops->content_size(config, buf, &cs);
1485                 if (ret < 0)
1486                         goto error;
1487                 return put_u64(cs, arg);
1488         }
1489         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1490         {
1491                 uint64_t ps;
1492
1493                 if (!lttng_chan->ops)
1494                         goto error;
1495                 ret = lttng_chan->ops->packet_size(config, buf, &ps);
1496                 if (ret < 0)
1497                         goto error;
1498                 return put_u64(ps, arg);
1499         }
1500         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1501         {
1502                 uint64_t si;
1503
1504                 if (!lttng_chan->ops)
1505                         goto error;
1506                 ret = lttng_chan->ops->stream_id(config, buf, &si);
1507                 if (ret < 0)
1508                         goto error;
1509                 return put_u64(si, arg);
1510         }
1511         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1512         {
1513                 uint64_t ts;
1514
1515                 if (!lttng_chan->ops)
1516                         goto error;
1517                 ret = lttng_chan->ops->current_timestamp(config, buf, &ts);
1518                 if (ret < 0)
1519                         goto error;
1520                 return put_u64(ts, arg);
1521         }
1522         default:
1523                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1524                                 cmd, arg);
1525         }
1526
1527 error:
1528         return -ENOSYS;
1529 }
1530 #endif /* CONFIG_COMPAT */
1531
1532 static void lttng_stream_override_ring_buffer_fops(void)
1533 {
1534         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1535         lttng_stream_ring_buffer_file_operations.open =
1536                 lib_ring_buffer_file_operations.open;
1537         lttng_stream_ring_buffer_file_operations.release =
1538                 lib_ring_buffer_file_operations.release;
1539         lttng_stream_ring_buffer_file_operations.poll =
1540                 lib_ring_buffer_file_operations.poll;
1541         lttng_stream_ring_buffer_file_operations.splice_read =
1542                 lib_ring_buffer_file_operations.splice_read;
1543         lttng_stream_ring_buffer_file_operations.mmap =
1544                 lib_ring_buffer_file_operations.mmap;
1545         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1546                 lttng_stream_ring_buffer_ioctl;
1547         lttng_stream_ring_buffer_file_operations.llseek =
1548                 lib_ring_buffer_file_operations.llseek;
1549 #ifdef CONFIG_COMPAT
1550         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1551                 lttng_stream_ring_buffer_compat_ioctl;
1552 #endif
1553 }
1554
1555 int __init lttng_abi_init(void)
1556 {
1557         int ret = 0;
1558
1559         wrapper_vmalloc_sync_all();
1560         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1561                                         &lttng_fops, NULL);
1562
1563         if (!lttng_proc_dentry) {
1564                 printk(KERN_ERR "Error creating LTTng control file\n");
1565                 ret = -ENOMEM;
1566                 goto error;
1567         }
1568         lttng_stream_override_ring_buffer_fops();
1569
1570 error:
1571         return ret;
1572 }
1573
1574 void __exit lttng_abi_exit(void)
1575 {
1576         if (lttng_proc_dentry)
1577                 remove_proc_entry("lttng", NULL);
1578 }