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 <linux/err.h>
  47 #include "wrapper/vmalloc.h"    /* for wrapper_vmalloc_sync_all() */
  48 #include "wrapper/ringbuffer/vfs.h"
  49 #include "wrapper/ringbuffer/backend.h"
  50 #include "wrapper/ringbuffer/frontend.h"
  51 #include "wrapper/poll.h"
  52 #include "lttng-abi.h"
  53 #include "lttng-abi-old.h"
  54 #include "lttng-events.h"
  55 #include "lttng-tracer.h"
  56 #include "lib/ringbuffer/frontend_types.h"
  57
  58 /*
  59  * This is LTTng's own personal way to create a system call as an external
  60  * module. We use ioctl() on /proc/lttng.
  61  */
  62
  63 static struct proc_dir_entry *lttng_proc_dentry;
  64 static const struct file_operations lttng_fops;
  65 static const struct file_operations lttng_session_fops;
  66 static const struct file_operations lttng_channel_fops;
  67 static const struct file_operations lttng_metadata_fops;
  68 static const struct file_operations lttng_event_fops;
  69 static struct file_operations lttng_stream_ring_buffer_file_operations;
  70
  71 /*
  72  * Teardown management: opened file descriptors keep a refcount on the module,
  73  * so it can only exit when all file descriptors are closed.
  74  */
  75
  76 static
  77 int lttng_abi_create_session(void)
  78 {
  79         struct lttng_session *session;
  80         struct file *session_file;
  81         int session_fd, ret;
  82
  83         session = lttng_session_create();
  84         if (!session)
  85                 return -ENOMEM;
  86         session_fd = get_unused_fd();
  87         if (session_fd < 0) {
  88                 ret = session_fd;
  89                 goto fd_error;
  90         }
  91         session_file = anon_inode_getfile("[lttng_session]",
  92                                           &lttng_session_fops,
  93                                           session, O_RDWR);
  94         if (IS_ERR(session_file)) {
  95                 ret = PTR_ERR(session_file);
  96                 goto file_error;
  97         }
  98         session->file = session_file;
  99         fd_install(session_fd, session_file);
 100         return session_fd;
 101
 102 file_error:
 103         put_unused_fd(session_fd);
 104 fd_error:
 105         lttng_session_destroy(session);
 106         return ret;
 107 }
 108
 109 static
 110 int lttng_abi_tracepoint_list(void)
 111 {
 112         struct file *tracepoint_list_file;
 113         int file_fd, ret;
 114
 115         file_fd = get_unused_fd();
 116         if (file_fd < 0) {
 117                 ret = file_fd;
 118                 goto fd_error;
 119         }
 120
 121         tracepoint_list_file = anon_inode_getfile("[lttng_session]",
 122                                           &lttng_tracepoint_list_fops,
 123                                           NULL, O_RDWR);
 124         if (IS_ERR(tracepoint_list_file)) {
 125                 ret = PTR_ERR(tracepoint_list_file);
 126                 goto file_error;
 127         }
 128         ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
 129         if (ret < 0)
 130                 goto open_error;
 131         fd_install(file_fd, tracepoint_list_file);
 132         if (file_fd < 0) {
 133                 ret = file_fd;
 134                 goto fd_error;
 135         }
 136         return file_fd;
 137
 138 open_error:
 139         fput(tracepoint_list_file);
 140 file_error:
 141         put_unused_fd(file_fd);
 142 fd_error:
 143         return ret;
 144 }
 145
 146 static
 147 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
 148 {
 149         v->major = LTTNG_MODULES_MAJOR_VERSION;
 150         v->minor = LTTNG_MODULES_MINOR_VERSION;
 151         v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
 152 }
 153
 154 static
 155 long lttng_abi_add_context(struct file *file,
 156         struct lttng_kernel_context *context_param,
 157         struct lttng_ctx **ctx, struct lttng_session *session)
 158 {
 159
 160         if (session->been_active)
 161                 return -EPERM;
 162
 163         switch (context_param->ctx) {
 164         case LTTNG_KERNEL_CONTEXT_PID:
 165                 return lttng_add_pid_to_ctx(ctx);
 166         case LTTNG_KERNEL_CONTEXT_PRIO:
 167                 return lttng_add_prio_to_ctx(ctx);
 168         case LTTNG_KERNEL_CONTEXT_NICE:
 169                 return lttng_add_nice_to_ctx(ctx);
 170         case LTTNG_KERNEL_CONTEXT_VPID:
 171                 return lttng_add_vpid_to_ctx(ctx);
 172         case LTTNG_KERNEL_CONTEXT_TID:
 173                 return lttng_add_tid_to_ctx(ctx);
 174         case LTTNG_KERNEL_CONTEXT_VTID:
 175                 return lttng_add_vtid_to_ctx(ctx);
 176         case LTTNG_KERNEL_CONTEXT_PPID:
 177                 return lttng_add_ppid_to_ctx(ctx);
 178         case LTTNG_KERNEL_CONTEXT_VPPID:
 179                 return lttng_add_vppid_to_ctx(ctx);
 180         case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
 181                 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 182                 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
 183                                 context_param->u.perf_counter.config,
 184                                 context_param->u.perf_counter.name,
 185                                 ctx);
 186         case LTTNG_KERNEL_CONTEXT_PROCNAME:
 187                 return lttng_add_procname_to_ctx(ctx);
 188         case LTTNG_KERNEL_CONTEXT_HOSTNAME:
 189                 return lttng_add_hostname_to_ctx(ctx);
 190         default:
 191                 return -EINVAL;
 192         }
 193 }
 194
 195 /**
 196  *      lttng_ioctl - lttng syscall through ioctl
 197  *
 198  *      @file: the file
 199  *      @cmd: the command
 200  *      @arg: command arg
 201  *
 202  *      This ioctl implements lttng commands:
 203  *      LTTNG_KERNEL_SESSION
 204  *              Returns a LTTng trace session file descriptor
 205  *      LTTNG_KERNEL_TRACER_VERSION
 206  *              Returns the LTTng kernel tracer version
 207  *      LTTNG_KERNEL_TRACEPOINT_LIST
 208  *              Returns a file descriptor listing available tracepoints
 209  *      LTTNG_KERNEL_WAIT_QUIESCENT
 210  *              Returns after all previously running probes have completed
 211  *
 212  * The returned session will be deleted when its file descriptor is closed.
 213  */
 214 static
 215 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 216 {
 217         switch (cmd) {
 218         case LTTNG_KERNEL_OLD_SESSION:
 219         case LTTNG_KERNEL_SESSION:
 220                 return lttng_abi_create_session();
 221         case LTTNG_KERNEL_OLD_TRACER_VERSION:
 222         {
 223                 struct lttng_kernel_tracer_version v;
 224                 struct lttng_kernel_old_tracer_version oldv;
 225                 struct lttng_kernel_old_tracer_version *uversion =
 226                         (struct lttng_kernel_old_tracer_version __user *) arg;
 227
 228                 lttng_abi_tracer_version(&v);
 229                 oldv.major = v.major;
 230                 oldv.minor = v.minor;
 231                 oldv.patchlevel = v.patchlevel;
 232
 233                 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
 234                         return -EFAULT;
 235                 return 0;
 236         }
 237         case LTTNG_KERNEL_TRACER_VERSION:
 238         {
 239                 struct lttng_kernel_tracer_version version;
 240                 struct lttng_kernel_tracer_version *uversion =
 241                         (struct lttng_kernel_tracer_version __user *) arg;
 242
 243                 lttng_abi_tracer_version(&version);
 244
 245                 if (copy_to_user(uversion, &version, sizeof(version)))
 246                         return -EFAULT;
 247                 return 0;
 248         }
 249         case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
 250         case LTTNG_KERNEL_TRACEPOINT_LIST:
 251                 return lttng_abi_tracepoint_list();
 252         case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
 253         case LTTNG_KERNEL_WAIT_QUIESCENT:
 254                 synchronize_trace();
 255                 return 0;
 256         case LTTNG_KERNEL_OLD_CALIBRATE:
 257         {
 258                 struct lttng_kernel_old_calibrate __user *ucalibrate =
 259                         (struct lttng_kernel_old_calibrate __user *) arg;
 260                 struct lttng_kernel_old_calibrate old_calibrate;
 261                 struct lttng_kernel_calibrate calibrate;
 262                 int ret;
 263
 264                 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
 265                         return -EFAULT;
 266                 calibrate.type = old_calibrate.type;
 267                 ret = lttng_calibrate(&calibrate);
 268                 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
 269                         return -EFAULT;
 270                 return ret;
 271         }
 272         case LTTNG_KERNEL_CALIBRATE:
 273         {
 274                 struct lttng_kernel_calibrate __user *ucalibrate =
 275                         (struct lttng_kernel_calibrate __user *) arg;
 276                 struct lttng_kernel_calibrate calibrate;
 277                 int ret;
 278
 279                 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
 280                         return -EFAULT;
 281                 ret = lttng_calibrate(&calibrate);
 282                 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
 283                         return -EFAULT;
 284                 return ret;
 285         }
 286         default:
 287                 return -ENOIOCTLCMD;
 288         }
 289 }
 290
 291 static const struct file_operations lttng_fops = {
 292         .owner = THIS_MODULE,
 293         .unlocked_ioctl = lttng_ioctl,
 294 #ifdef CONFIG_COMPAT
 295         .compat_ioctl = lttng_ioctl,
 296 #endif
 297 };
 298
 299 static
 300 int lttng_abi_create_channel(struct file *session_file,
 301                              struct lttng_kernel_channel *chan_param,
 302                              enum channel_type channel_type)
 303 {
 304         struct lttng_session *session = session_file->private_data;
 305         const struct file_operations *fops = NULL;
 306         const char *transport_name;
 307         struct lttng_channel *chan;
 308         struct file *chan_file;
 309         int chan_fd;
 310         int ret = 0;
 311
 312         chan_fd = get_unused_fd();
 313         if (chan_fd < 0) {
 314                 ret = chan_fd;
 315                 goto fd_error;
 316         }
 317         switch (channel_type) {
 318         case PER_CPU_CHANNEL:
 319                 fops = &lttng_channel_fops;
 320                 break;
 321         case METADATA_CHANNEL:
 322                 fops = &lttng_metadata_fops;
 323                 break;
 324         }
 325
 326         chan_file = anon_inode_getfile("[lttng_channel]",
 327                                        fops,
 328                                        NULL, O_RDWR);
 329         if (IS_ERR(chan_file)) {
 330                 ret = PTR_ERR(chan_file);
 331                 goto file_error;
 332         }
 333         switch (channel_type) {
 334         case PER_CPU_CHANNEL:
 335                 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
 336                         transport_name = chan_param->overwrite ?
 337                                 "relay-overwrite" : "relay-discard";
 338                 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
 339                         transport_name = chan_param->overwrite ?
 340                                 "relay-overwrite-mmap" : "relay-discard-mmap";
 341                 } else {
 342                         return -EINVAL;
 343                 }
 344                 break;
 345         case METADATA_CHANNEL:
 346                 if (chan_param->output == LTTNG_KERNEL_SPLICE)
 347                         transport_name = "relay-metadata";
 348                 else if (chan_param->output == LTTNG_KERNEL_MMAP)
 349                         transport_name = "relay-metadata-mmap";
 350                 else
 351                         return -EINVAL;
 352                 break;
 353         default:
 354                 transport_name = "<unknown>";
 355                 break;
 356         }
 357         /*
 358          * We tolerate no failure path after channel creation. It will stay
 359          * invariant for the rest of the session.
 360          */
 361         chan = lttng_channel_create(session, transport_name, NULL,
 362                                   chan_param->subbuf_size,
 363                                   chan_param->num_subbuf,
 364                                   chan_param->switch_timer_interval,
 365                                   chan_param->read_timer_interval,
 366                                   channel_type);
 367         if (!chan) {
 368                 ret = -EINVAL;
 369                 goto chan_error;
 370         }
 371         chan->file = chan_file;
 372         chan_file->private_data = chan;
 373         fd_install(chan_fd, chan_file);
 374         atomic_long_inc(&session_file->f_count);
 375
 376         return chan_fd;
 377
 378 chan_error:
 379         fput(chan_file);
 380 file_error:
 381         put_unused_fd(chan_fd);
 382 fd_error:
 383         return ret;
 384 }
 385
 386 /**
 387  *      lttng_session_ioctl - lttng session fd ioctl
 388  *
 389  *      @file: the file
 390  *      @cmd: the command
 391  *      @arg: command arg
 392  *
 393  *      This ioctl implements lttng commands:
 394  *      LTTNG_KERNEL_CHANNEL
 395  *              Returns a LTTng channel file descriptor
 396  *      LTTNG_KERNEL_ENABLE
 397  *              Enables tracing for a session (weak enable)
 398  *      LTTNG_KERNEL_DISABLE
 399  *              Disables tracing for a session (strong disable)
 400  *      LTTNG_KERNEL_METADATA
 401  *              Returns a LTTng metadata file descriptor
 402  *
 403  * The returned channel will be deleted when its file descriptor is closed.
 404  */
 405 static
 406 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 407 {
 408         struct lttng_session *session = file->private_data;
 409
 410         switch (cmd) {
 411         case LTTNG_KERNEL_OLD_CHANNEL:
 412         {
 413                 struct lttng_kernel_channel chan_param;
 414                 struct lttng_kernel_old_channel old_chan_param;
 415
 416                 if (copy_from_user(&old_chan_param,
 417                                 (struct lttng_kernel_old_channel __user *) arg,
 418                                 sizeof(struct lttng_kernel_old_channel)))
 419                         return -EFAULT;
 420                 chan_param.overwrite = old_chan_param.overwrite;
 421                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 422                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 423                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 424                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 425                 chan_param.output = old_chan_param.output;
 426
 427                 return lttng_abi_create_channel(file, &chan_param,
 428                                 PER_CPU_CHANNEL);
 429         }
 430         case LTTNG_KERNEL_CHANNEL:
 431         {
 432                 struct lttng_kernel_channel chan_param;
 433
 434                 if (copy_from_user(&chan_param,
 435                                 (struct lttng_kernel_channel __user *) arg,
 436                                 sizeof(struct lttng_kernel_channel)))
 437                         return -EFAULT;
 438                 return lttng_abi_create_channel(file, &chan_param,
 439                                 PER_CPU_CHANNEL);
 440         }
 441         case LTTNG_KERNEL_OLD_SESSION_START:
 442         case LTTNG_KERNEL_OLD_ENABLE:
 443         case LTTNG_KERNEL_SESSION_START:
 444         case LTTNG_KERNEL_ENABLE:
 445                 return lttng_session_enable(session);
 446         case LTTNG_KERNEL_OLD_SESSION_STOP:
 447         case LTTNG_KERNEL_OLD_DISABLE:
 448         case LTTNG_KERNEL_SESSION_STOP:
 449         case LTTNG_KERNEL_DISABLE:
 450                 return lttng_session_disable(session);
 451         case LTTNG_KERNEL_OLD_METADATA:
 452         {
 453                 struct lttng_kernel_channel chan_param;
 454                 struct lttng_kernel_old_channel old_chan_param;
 455
 456                 if (copy_from_user(&old_chan_param,
 457                                 (struct lttng_kernel_old_channel __user *) arg,
 458                                 sizeof(struct lttng_kernel_old_channel)))
 459                         return -EFAULT;
 460                 chan_param.overwrite = old_chan_param.overwrite;
 461                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 462                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 463                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 464                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 465                 chan_param.output = old_chan_param.output;
 466
 467                 return lttng_abi_create_channel(file, &chan_param,
 468                                 METADATA_CHANNEL);
 469         }
 470         case LTTNG_KERNEL_METADATA:
 471         {
 472                 struct lttng_kernel_channel chan_param;
 473
 474                 if (copy_from_user(&chan_param,
 475                                         (struct lttng_kernel_channel __user *) arg,
 476                                         sizeof(struct lttng_kernel_channel)))
 477                         return -EFAULT;
 478                 return lttng_abi_create_channel(file, &chan_param,
 479                                 METADATA_CHANNEL);
 480         }
 481         default:
 482                 return -ENOIOCTLCMD;
 483         }
 484 }
 485
 486 /*
 487  * Called when the last file reference is dropped.
 488  *
 489  * Big fat note: channels and events are invariant for the whole session after
 490  * their creation. So this session destruction also destroys all channel and
 491  * event structures specific to this session (they are not destroyed when their
 492  * individual file is released).
 493  */
 494 static
 495 int lttng_session_release(struct inode *inode, struct file *file)
 496 {
 497         struct lttng_session *session = file->private_data;
 498
 499         if (session)
 500                 lttng_session_destroy(session);
 501         return 0;
 502 }
 503
 504 static const struct file_operations lttng_session_fops = {
 505         .owner = THIS_MODULE,
 506         .release = lttng_session_release,
 507         .unlocked_ioctl = lttng_session_ioctl,
 508 #ifdef CONFIG_COMPAT
 509         .compat_ioctl = lttng_session_ioctl,
 510 #endif
 511 };
 512
 513 /**
 514  *      lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
 515  *      @filp: the file
 516  *      @wait: poll table
 517  *
 518  *      Handles the poll operations for the metadata channels.
 519  */
 520 static
 521 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 522                 poll_table *wait)
 523 {
 524         struct lttng_metadata_stream *stream = filp->private_data;
 525         struct lib_ring_buffer *buf = stream->priv;
 526         int finalized;
 527         unsigned int mask = 0;
 528
 529         if (filp->f_mode & FMODE_READ) {
 530                 poll_wait_set_exclusive(wait);
 531                 poll_wait(filp, &stream->read_wait, wait);
 532
 533                 finalized = stream->finalized;
 534
 535                 /*
 536                  * lib_ring_buffer_is_finalized() contains a smp_rmb()
 537                  * ordering finalized load before offsets loads.
 538                  */
 539                 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
 540
 541                 if (finalized)
 542                         mask |= POLLHUP;
 543
 544                 if (stream->metadata_cache->metadata_written >
 545                                 stream->metadata_out)
 546                         mask |= POLLIN;
 547         }
 548
 549         return mask;
 550 }
 551
 552 static
 553 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 554                 unsigned int cmd, unsigned long arg)
 555 {
 556         struct lttng_metadata_stream *stream = filp->private_data;
 557
 558         stream->metadata_out = stream->metadata_in;
 559 }
 560
 561 static
 562 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 563                 unsigned int cmd, unsigned long arg)
 564 {
 565         int ret;
 566         struct lttng_metadata_stream *stream = filp->private_data;
 567         struct lib_ring_buffer *buf = stream->priv;
 568
 569         switch (cmd) {
 570         case RING_BUFFER_GET_NEXT_SUBBUF:
 571         {
 572                 struct lttng_metadata_stream *stream = filp->private_data;
 573                 struct lib_ring_buffer *buf = stream->priv;
 574                 struct channel *chan = buf->backend.chan;
 575
 576                 ret = lttng_metadata_output_channel(stream, chan);
 577                 if (ret > 0) {
 578                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 579                         ret = 0;
 580                 } else if (ret < 0)
 581                         goto err;
 582                 break;
 583         }
 584         case RING_BUFFER_GET_SUBBUF:
 585         {
 586                 /*
 587                  * Random access is not allowed for metadata channel.
 588                  */
 589                 return -ENOSYS;
 590         }
 591         case RING_BUFFER_FLUSH:
 592         {
 593                 struct lttng_metadata_stream *stream = filp->private_data;
 594                 struct lib_ring_buffer *buf = stream->priv;
 595                 struct channel *chan = buf->backend.chan;
 596
 597                 /*
 598                  * Before doing the actual ring buffer flush, write up to one
 599                  * packet of metadata in the ring buffer.
 600                  */
 601                 ret = lttng_metadata_output_channel(stream, chan);
 602                 if (ret < 0)
 603                         goto err;
 604                 break;
 605         }
 606         default:
 607                 break;
 608         }
 609         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 610
 611         /* Performing lib ring buffer ioctl after our own. */
 612         ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
 613         if (ret < 0)
 614                 goto err;
 615
 616         switch (cmd) {
 617         case RING_BUFFER_PUT_NEXT_SUBBUF:
 618         {
 619                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 620                                 cmd, arg);
 621                 break;
 622         }
 623         default:
 624                 break;
 625         }
 626 err:
 627         return ret;
 628 }
 629
 630 #ifdef CONFIG_COMPAT
 631 static
 632 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 633                 unsigned int cmd, unsigned long arg)
 634 {
 635         int ret;
 636         struct lttng_metadata_stream *stream = filp->private_data;
 637         struct lib_ring_buffer *buf = stream->priv;
 638
 639         switch (cmd) {
 640         case RING_BUFFER_GET_NEXT_SUBBUF:
 641         {
 642                 struct lttng_metadata_stream *stream = filp->private_data;
 643                 struct lib_ring_buffer *buf = stream->priv;
 644                 struct channel *chan = buf->backend.chan;
 645
 646                 ret = lttng_metadata_output_channel(stream, chan);
 647                 if (ret > 0) {
 648                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 649                         ret = 0;
 650                 } else if (ret < 0)
 651                         goto err;
 652                 break;
 653         }
 654         case RING_BUFFER_GET_SUBBUF:
 655         {
 656                 /*
 657                  * Random access is not allowed for metadata channel.
 658                  */
 659                 return -ENOSYS;
 660         }
 661         default:
 662                 break;
 663         }
 664         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 665
 666         /* Performing lib ring buffer ioctl after our own. */
 667         ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
 668         if (ret < 0)
 669                 goto err;
 670
 671         switch (cmd) {
 672         case RING_BUFFER_PUT_NEXT_SUBBUF:
 673         {
 674                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 675                                 cmd, arg);
 676                 break;
 677         }
 678         default:
 679                 break;
 680         }
 681 err:
 682         return ret;
 683 }
 684 #endif
 685
 686 /*
 687  * This is not used by anonymous file descriptors. This code is left
 688  * there if we ever want to implement an inode with open() operation.
 689  */
 690 static
 691 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 692 {
 693         struct lttng_metadata_stream *stream = inode->i_private;
 694         struct lib_ring_buffer *buf = stream->priv;
 695
 696         file->private_data = buf;
 697         /*
 698          * Since life-time of metadata cache differs from that of
 699          * session, we need to keep our own reference on the transport.
 700          */
 701         if (!try_module_get(stream->transport->owner)) {
 702                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 703                 return -EBUSY;
 704         }
 705         return lib_ring_buffer_open(inode, file, buf);
 706 }
 707
 708 static
 709 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
 710 {
 711         struct lttng_metadata_stream *stream = file->private_data;
 712         struct lib_ring_buffer *buf = stream->priv;
 713
 714         kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
 715         module_put(stream->transport->owner);
 716         return lib_ring_buffer_release(inode, file, buf);
 717 }
 718
 719 static
 720 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 721                 struct pipe_inode_info *pipe, size_t len,
 722                 unsigned int flags)
 723 {
 724         struct lttng_metadata_stream *stream = in->private_data;
 725         struct lib_ring_buffer *buf = stream->priv;
 726
 727         return lib_ring_buffer_splice_read(in, ppos, pipe, len,
 728                         flags, buf);
 729 }
 730
 731 static
 732 int lttng_metadata_ring_buffer_mmap(struct file *filp,
 733                 struct vm_area_struct *vma)
 734 {
 735         struct lttng_metadata_stream *stream = filp->private_data;
 736         struct lib_ring_buffer *buf = stream->priv;
 737
 738         return lib_ring_buffer_mmap(filp, vma, buf);
 739 }
 740
 741 static
 742 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
 743         .owner = THIS_MODULE,
 744         .open = lttng_metadata_ring_buffer_open,
 745         .release = lttng_metadata_ring_buffer_release,
 746         .poll = lttng_metadata_ring_buffer_poll,
 747         .splice_read = lttng_metadata_ring_buffer_splice_read,
 748         .mmap = lttng_metadata_ring_buffer_mmap,
 749         .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
 750         .llseek = vfs_lib_ring_buffer_no_llseek,
 751 #ifdef CONFIG_COMPAT
 752         .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
 753 #endif
 754 };
 755
 756 static
 757 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
 758                 const struct file_operations *fops)
 759 {
 760         int stream_fd, ret;
 761         struct file *stream_file;
 762
 763         stream_fd = get_unused_fd();
 764         if (stream_fd < 0) {
 765                 ret = stream_fd;
 766                 goto fd_error;
 767         }
 768         stream_file = anon_inode_getfile("[lttng_stream]", fops,
 769                         stream_priv, O_RDWR);
 770         if (IS_ERR(stream_file)) {
 771                 ret = PTR_ERR(stream_file);
 772                 goto file_error;
 773         }
 774         /*
 775          * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
 776          * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
 777          * file descriptor, so we set FMODE_PREAD here.
 778          */
 779         stream_file->f_mode |= FMODE_PREAD;
 780         fd_install(stream_fd, stream_file);
 781         /*
 782          * The stream holds a reference to the channel within the generic ring
 783          * buffer library, so no need to hold a refcount on the channel and
 784          * session files here.
 785          */
 786         return stream_fd;
 787
 788 file_error:
 789         put_unused_fd(stream_fd);
 790 fd_error:
 791         return ret;
 792 }
 793
 794 static
 795 int lttng_abi_open_stream(struct file *channel_file)
 796 {
 797         struct lttng_channel *channel = channel_file->private_data;
 798         struct lib_ring_buffer *buf;
 799         int ret;
 800         void *stream_priv;
 801
 802         buf = channel->ops->buffer_read_open(channel->chan);
 803         if (!buf)
 804                 return -ENOENT;
 805
 806         stream_priv = buf;
 807         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 808                         &lttng_stream_ring_buffer_file_operations);
 809         if (ret < 0)
 810                 goto fd_error;
 811
 812         return ret;
 813
 814 fd_error:
 815         channel->ops->buffer_read_close(buf);
 816         return ret;
 817 }
 818
 819 static
 820 int lttng_abi_open_metadata_stream(struct file *channel_file)
 821 {
 822         struct lttng_channel *channel = channel_file->private_data;
 823         struct lttng_session *session = channel->session;
 824         struct lib_ring_buffer *buf;
 825         int ret;
 826         struct lttng_metadata_stream *metadata_stream;
 827         void *stream_priv;
 828
 829         buf = channel->ops->buffer_read_open(channel->chan);
 830         if (!buf)
 831                 return -ENOENT;
 832
 833         metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
 834                         GFP_KERNEL);
 835         if (!metadata_stream) {
 836                 ret = -ENOMEM;
 837                 goto nomem;
 838         }
 839         metadata_stream->metadata_cache = session->metadata_cache;
 840         init_waitqueue_head(&metadata_stream->read_wait);
 841         metadata_stream->priv = buf;
 842         stream_priv = metadata_stream;
 843         metadata_stream->transport = channel->transport;
 844
 845         /*
 846          * Since life-time of metadata cache differs from that of
 847          * session, we need to keep our own reference on the transport.
 848          */
 849         if (!try_module_get(metadata_stream->transport->owner)) {
 850                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 851                 ret = -EINVAL;
 852                 goto notransport;
 853         }
 854
 855         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 856                         &lttng_metadata_ring_buffer_file_operations);
 857         if (ret < 0)
 858                 goto fd_error;
 859
 860         kref_get(&session->metadata_cache->refcount);
 861         list_add(&metadata_stream->list,
 862                 &session->metadata_cache->metadata_stream);
 863         return ret;
 864
 865 fd_error:
 866         module_put(metadata_stream->transport->owner);
 867 notransport:
 868         kfree(metadata_stream);
 869 nomem:
 870         channel->ops->buffer_read_close(buf);
 871         return ret;
 872 }
 873
 874 static
 875 int lttng_abi_create_event(struct file *channel_file,
 876                            struct lttng_kernel_event *event_param)
 877 {
 878         struct lttng_channel *channel = channel_file->private_data;
 879         struct lttng_event *event;
 880         int event_fd, ret;
 881         struct file *event_file;
 882
 883         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 884         switch (event_param->instrumentation) {
 885         case LTTNG_KERNEL_KRETPROBE:
 886                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 887                 break;
 888         case LTTNG_KERNEL_KPROBE:
 889                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 890                 break;
 891         case LTTNG_KERNEL_FUNCTION:
 892                 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 893                 break;
 894         default:
 895                 break;
 896         }
 897         switch (event_param->instrumentation) {
 898         default:
 899                 event_fd = get_unused_fd();
 900                 if (event_fd < 0) {
 901                         ret = event_fd;
 902                         goto fd_error;
 903                 }
 904                 event_file = anon_inode_getfile("[lttng_event]",
 905                                                 &lttng_event_fops,
 906                                                 NULL, O_RDWR);
 907                 if (IS_ERR(event_file)) {
 908                         ret = PTR_ERR(event_file);
 909                         goto file_error;
 910                 }
 911                 /*
 912                  * We tolerate no failure path after event creation. It
 913                  * will stay invariant for the rest of the session.
 914                  */
 915                 event = lttng_event_create(channel, event_param, NULL, NULL);
 916                 WARN_ON_ONCE(!event);
 917                 if (IS_ERR(event)) {
 918                         ret = PTR_ERR(event);
 919                         goto event_error;
 920                 }
 921                 event_file->private_data = event;
 922                 fd_install(event_fd, event_file);
 923                 /* The event holds a reference on the channel */
 924                 atomic_long_inc(&channel_file->f_count);
 925                 break;
 926         case LTTNG_KERNEL_SYSCALL:
 927                 /*
 928                  * Only all-syscall tracing supported for now.
 929                  */
 930                 if (event_param->name[0] != '\0')
 931                         return -EINVAL;
 932                 ret = lttng_syscalls_register(channel, NULL);
 933                 if (ret)
 934                         goto fd_error;
 935                 event_fd = 0;
 936                 break;
 937         }
 938         return event_fd;
 939
 940 event_error:
 941         fput(event_file);
 942 file_error:
 943         put_unused_fd(event_fd);
 944 fd_error:
 945         return ret;
 946 }
 947
 948 /**
 949  *      lttng_channel_ioctl - lttng syscall through ioctl
 950  *
 951  *      @file: the file
 952  *      @cmd: the command
 953  *      @arg: command arg
 954  *
 955  *      This ioctl implements lttng commands:
 956  *      LTTNG_KERNEL_STREAM
 957  *              Returns an event stream file descriptor or failure.
 958  *              (typically, one event stream records events from one CPU)
 959  *      LTTNG_KERNEL_EVENT
 960  *              Returns an event file descriptor or failure.
 961  *      LTTNG_KERNEL_CONTEXT
 962  *              Prepend a context field to each event in the channel
 963  *      LTTNG_KERNEL_ENABLE
 964  *              Enable recording for events in this channel (weak enable)
 965  *      LTTNG_KERNEL_DISABLE
 966  *              Disable recording for events in this channel (strong disable)
 967  *
 968  * Channel and event file descriptors also hold a reference on the session.
 969  */
 970 static
 971 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 972 {
 973         struct lttng_channel *channel = file->private_data;
 974
 975         switch (cmd) {
 976         case LTTNG_KERNEL_OLD_STREAM:
 977         case LTTNG_KERNEL_STREAM:
 978                 return lttng_abi_open_stream(file);
 979         case LTTNG_KERNEL_OLD_EVENT:
 980         {
 981                 struct lttng_kernel_event *uevent_param;
 982                 struct lttng_kernel_old_event *old_uevent_param;
 983                 int ret;
 984
 985                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
 986                                 GFP_KERNEL);
 987                 if (!uevent_param) {
 988                         ret = -ENOMEM;
 989                         goto old_event_end;
 990                 }
 991                 old_uevent_param = kmalloc(
 992                                 sizeof(struct lttng_kernel_old_event),
 993                                 GFP_KERNEL);
 994                 if (!old_uevent_param) {
 995                         ret = -ENOMEM;
 996                         goto old_event_error_free_param;
 997                 }
 998                 if (copy_from_user(old_uevent_param,
 999                                 (struct lttng_kernel_old_event __user *) arg,
1000                                 sizeof(struct lttng_kernel_old_event))) {
1001                         ret = -EFAULT;
1002                         goto old_event_error_free_old_param;
1003                 }
1004
1005                 memcpy(uevent_param->name, old_uevent_param->name,
1006                                 sizeof(uevent_param->name));
1007                 uevent_param->instrumentation =
1008                         old_uevent_param->instrumentation;
1009
1010                 switch (old_uevent_param->instrumentation) {
1011                 case LTTNG_KERNEL_KPROBE:
1012                         uevent_param->u.kprobe.addr =
1013                                 old_uevent_param->u.kprobe.addr;
1014                         uevent_param->u.kprobe.offset =
1015                                 old_uevent_param->u.kprobe.offset;
1016                         memcpy(uevent_param->u.kprobe.symbol_name,
1017                                 old_uevent_param->u.kprobe.symbol_name,
1018                                 sizeof(uevent_param->u.kprobe.symbol_name));
1019                         break;
1020                 case LTTNG_KERNEL_KRETPROBE:
1021                         uevent_param->u.kretprobe.addr =
1022                                 old_uevent_param->u.kretprobe.addr;
1023                         uevent_param->u.kretprobe.offset =
1024                                 old_uevent_param->u.kretprobe.offset;
1025                         memcpy(uevent_param->u.kretprobe.symbol_name,
1026                                 old_uevent_param->u.kretprobe.symbol_name,
1027                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1028                         break;
1029                 case LTTNG_KERNEL_FUNCTION:
1030                         memcpy(uevent_param->u.ftrace.symbol_name,
1031                                         old_uevent_param->u.ftrace.symbol_name,
1032                                         sizeof(uevent_param->u.ftrace.symbol_name));
1033                         break;
1034                 default:
1035                         break;
1036                 }
1037                 ret = lttng_abi_create_event(file, uevent_param);
1038
1039 old_event_error_free_old_param:
1040                 kfree(old_uevent_param);
1041 old_event_error_free_param:
1042                 kfree(uevent_param);
1043 old_event_end:
1044                 return ret;
1045         }
1046         case LTTNG_KERNEL_EVENT:
1047         {
1048                 struct lttng_kernel_event uevent_param;
1049
1050                 if (copy_from_user(&uevent_param,
1051                                 (struct lttng_kernel_event __user *) arg,
1052                                 sizeof(uevent_param)))
1053                         return -EFAULT;
1054                 return lttng_abi_create_event(file, &uevent_param);
1055         }
1056         case LTTNG_KERNEL_OLD_CONTEXT:
1057         {
1058                 struct lttng_kernel_context *ucontext_param;
1059                 struct lttng_kernel_old_context *old_ucontext_param;
1060                 int ret;
1061
1062                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1063                                 GFP_KERNEL);
1064                 if (!ucontext_param) {
1065                         ret = -ENOMEM;
1066                         goto old_ctx_end;
1067                 }
1068                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1069                                 GFP_KERNEL);
1070                 if (!old_ucontext_param) {
1071                         ret = -ENOMEM;
1072                         goto old_ctx_error_free_param;
1073                 }
1074
1075                 if (copy_from_user(old_ucontext_param,
1076                                 (struct lttng_kernel_old_context __user *) arg,
1077                                 sizeof(struct lttng_kernel_old_context))) {
1078                         ret = -EFAULT;
1079                         goto old_ctx_error_free_old_param;
1080                 }
1081                 ucontext_param->ctx = old_ucontext_param->ctx;
1082                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1083                                 sizeof(ucontext_param->padding));
1084                 /* only type that uses the union */
1085                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1086                         ucontext_param->u.perf_counter.type =
1087                                 old_ucontext_param->u.perf_counter.type;
1088                         ucontext_param->u.perf_counter.config =
1089                                 old_ucontext_param->u.perf_counter.config;
1090                         memcpy(ucontext_param->u.perf_counter.name,
1091                                 old_ucontext_param->u.perf_counter.name,
1092                                 sizeof(ucontext_param->u.perf_counter.name));
1093                 }
1094
1095                 ret = lttng_abi_add_context(file,
1096                                 ucontext_param,
1097                                 &channel->ctx, channel->session);
1098
1099 old_ctx_error_free_old_param:
1100                 kfree(old_ucontext_param);
1101 old_ctx_error_free_param:
1102                 kfree(ucontext_param);
1103 old_ctx_end:
1104                 return ret;
1105         }
1106         case LTTNG_KERNEL_CONTEXT:
1107         {
1108                 struct lttng_kernel_context ucontext_param;
1109
1110                 if (copy_from_user(&ucontext_param,
1111                                 (struct lttng_kernel_context __user *) arg,
1112                                 sizeof(ucontext_param)))
1113                         return -EFAULT;
1114                 return lttng_abi_add_context(file,
1115                                 &ucontext_param,
1116                                 &channel->ctx, channel->session);
1117         }
1118         case LTTNG_KERNEL_OLD_ENABLE:
1119         case LTTNG_KERNEL_ENABLE:
1120                 return lttng_channel_enable(channel);
1121         case LTTNG_KERNEL_OLD_DISABLE:
1122         case LTTNG_KERNEL_DISABLE:
1123                 return lttng_channel_disable(channel);
1124         default:
1125                 return -ENOIOCTLCMD;
1126         }
1127
1128 }
1129
1130 /**
1131  *      lttng_metadata_ioctl - lttng syscall through ioctl
1132  *
1133  *      @file: the file
1134  *      @cmd: the command
1135  *      @arg: command arg
1136  *
1137  *      This ioctl implements lttng commands:
1138  *      LTTNG_KERNEL_STREAM
1139  *              Returns an event stream file descriptor or failure.
1140  *
1141  * Channel and event file descriptors also hold a reference on the session.
1142  */
1143 static
1144 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1145 {
1146         switch (cmd) {
1147         case LTTNG_KERNEL_OLD_STREAM:
1148         case LTTNG_KERNEL_STREAM:
1149                 return lttng_abi_open_metadata_stream(file);
1150         default:
1151                 return -ENOIOCTLCMD;
1152         }
1153 }
1154
1155 /**
1156  *      lttng_channel_poll - lttng stream addition/removal monitoring
1157  *
1158  *      @file: the file
1159  *      @wait: poll table
1160  */
1161 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1162 {
1163         struct lttng_channel *channel = file->private_data;
1164         unsigned int mask = 0;
1165
1166         if (file->f_mode & FMODE_READ) {
1167                 poll_wait_set_exclusive(wait);
1168                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1169                           wait);
1170
1171                 if (channel->ops->is_disabled(channel->chan))
1172                         return POLLERR;
1173                 if (channel->ops->is_finalized(channel->chan))
1174                         return POLLHUP;
1175                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1176                         return POLLIN | POLLRDNORM;
1177                 return 0;
1178         }
1179         return mask;
1180
1181 }
1182
1183 static
1184 int lttng_channel_release(struct inode *inode, struct file *file)
1185 {
1186         struct lttng_channel *channel = file->private_data;
1187
1188         if (channel)
1189                 fput(channel->session->file);
1190         return 0;
1191 }
1192
1193 static
1194 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1195 {
1196         struct lttng_channel *channel = file->private_data;
1197
1198         if (channel) {
1199                 lttng_metadata_channel_destroy(channel);
1200                 fput(channel->session->file);
1201         }
1202
1203         return 0;
1204 }
1205
1206 static const struct file_operations lttng_channel_fops = {
1207         .owner = THIS_MODULE,
1208         .release = lttng_channel_release,
1209         .poll = lttng_channel_poll,
1210         .unlocked_ioctl = lttng_channel_ioctl,
1211 #ifdef CONFIG_COMPAT
1212         .compat_ioctl = lttng_channel_ioctl,
1213 #endif
1214 };
1215
1216 static const struct file_operations lttng_metadata_fops = {
1217         .owner = THIS_MODULE,
1218         .release = lttng_metadata_channel_release,
1219         .unlocked_ioctl = lttng_metadata_ioctl,
1220 #ifdef CONFIG_COMPAT
1221         .compat_ioctl = lttng_metadata_ioctl,
1222 #endif
1223 };
1224
1225 /**
1226  *      lttng_event_ioctl - lttng syscall through ioctl
1227  *
1228  *      @file: the file
1229  *      @cmd: the command
1230  *      @arg: command arg
1231  *
1232  *      This ioctl implements lttng commands:
1233  *      LTTNG_KERNEL_CONTEXT
1234  *              Prepend a context field to each record of this event
1235  *      LTTNG_KERNEL_ENABLE
1236  *              Enable recording for this event (weak enable)
1237  *      LTTNG_KERNEL_DISABLE
1238  *              Disable recording for this event (strong disable)
1239  */
1240 static
1241 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1242 {
1243         struct lttng_event *event = file->private_data;
1244
1245         switch (cmd) {
1246         case LTTNG_KERNEL_OLD_CONTEXT:
1247         {
1248                 struct lttng_kernel_context *ucontext_param;
1249                 struct lttng_kernel_old_context *old_ucontext_param;
1250                 int ret;
1251
1252                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1253                                 GFP_KERNEL);
1254                 if (!ucontext_param) {
1255                         ret = -ENOMEM;
1256                         goto old_ctx_end;
1257                 }
1258                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1259                                 GFP_KERNEL);
1260                 if (!old_ucontext_param) {
1261                         ret = -ENOMEM;
1262                         goto old_ctx_error_free_param;
1263                 }
1264
1265                 if (copy_from_user(old_ucontext_param,
1266                                         (struct lttng_kernel_old_context __user *) arg,
1267                                         sizeof(struct lttng_kernel_old_context))) {
1268                         ret = -EFAULT;
1269                         goto old_ctx_error_free_old_param;
1270                 }
1271                 ucontext_param->ctx = old_ucontext_param->ctx;
1272                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1273                                 sizeof(ucontext_param->padding));
1274                 /* only type that uses the union */
1275                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1276                         ucontext_param->u.perf_counter.type =
1277                                 old_ucontext_param->u.perf_counter.type;
1278                         ucontext_param->u.perf_counter.config =
1279                                 old_ucontext_param->u.perf_counter.config;
1280                         memcpy(ucontext_param->u.perf_counter.name,
1281                                         old_ucontext_param->u.perf_counter.name,
1282                                         sizeof(ucontext_param->u.perf_counter.name));
1283                 }
1284
1285                 ret = lttng_abi_add_context(file,
1286                                 ucontext_param,
1287                                 &event->ctx, event->chan->session);
1288
1289 old_ctx_error_free_old_param:
1290                 kfree(old_ucontext_param);
1291 old_ctx_error_free_param:
1292                 kfree(ucontext_param);
1293 old_ctx_end:
1294                 return ret;
1295         }
1296         case LTTNG_KERNEL_CONTEXT:
1297         {
1298                 struct lttng_kernel_context ucontext_param;
1299
1300                 if (copy_from_user(&ucontext_param,
1301                                         (struct lttng_kernel_context __user *) arg,
1302                                         sizeof(ucontext_param)))
1303                         return -EFAULT;
1304                 return lttng_abi_add_context(file,
1305                                 &ucontext_param,
1306                                 &event->ctx, event->chan->session);
1307         }
1308         case LTTNG_KERNEL_OLD_ENABLE:
1309         case LTTNG_KERNEL_ENABLE:
1310                 return lttng_event_enable(event);
1311         case LTTNG_KERNEL_OLD_DISABLE:
1312         case LTTNG_KERNEL_DISABLE:
1313                 return lttng_event_disable(event);
1314         default:
1315                 return -ENOIOCTLCMD;
1316         }
1317 }
1318
1319 static
1320 int lttng_event_release(struct inode *inode, struct file *file)
1321 {
1322         struct lttng_event *event = file->private_data;
1323
1324         if (event)
1325                 fput(event->chan->file);
1326         return 0;
1327 }
1328
1329 /* TODO: filter control ioctl */
1330 static const struct file_operations lttng_event_fops = {
1331         .owner = THIS_MODULE,
1332         .release = lttng_event_release,
1333         .unlocked_ioctl = lttng_event_ioctl,
1334 #ifdef CONFIG_COMPAT
1335         .compat_ioctl = lttng_event_ioctl,
1336 #endif
1337 };
1338
1339 static int put_u64(uint64_t val, unsigned long arg)
1340 {
1341         return put_user(val, (uint64_t __user *) arg);
1342 }
1343
1344 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1345                 unsigned int cmd, unsigned long arg)
1346 {
1347         struct lib_ring_buffer *buf = filp->private_data;
1348         struct channel *chan = buf->backend.chan;
1349         const struct lib_ring_buffer_config *config = &chan->backend.config;
1350         struct lttng_channel *lttng_chan = channel_get_private(chan);
1351         int ret;
1352
1353         if (atomic_read(&chan->record_disabled))
1354                 return -EIO;
1355
1356         switch (cmd) {
1357         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1358         {
1359                 uint64_t ts;
1360
1361                 if (!lttng_chan->ops)
1362                         goto error;
1363                 ret = lttng_chan->ops->timestamp_begin(config, buf, &ts);
1364                 if (ret < 0)
1365                         goto error;
1366                 return put_u64(ts, arg);
1367         }
1368         case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1369         {
1370                 uint64_t ts;
1371
1372                 if (!lttng_chan->ops)
1373                         goto error;
1374                 ret = lttng_chan->ops->timestamp_end(config, buf, &ts);
1375                 if (ret < 0)
1376                         goto error;
1377                 return put_u64(ts, arg);
1378         }
1379         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1380         {
1381                 uint64_t ed;
1382
1383                 if (!lttng_chan->ops)
1384                         goto error;
1385                 ret = lttng_chan->ops->events_discarded(config, buf, &ed);
1386                 if (ret < 0)
1387                         goto error;
1388                 return put_u64(ed, arg);
1389         }
1390         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1391         {
1392                 uint64_t cs;
1393
1394                 if (!lttng_chan->ops)
1395                         goto error;
1396                 ret = lttng_chan->ops->content_size(config, buf, &cs);
1397                 if (ret < 0)
1398                         goto error;
1399                 return put_u64(cs, arg);
1400         }
1401         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1402         {
1403                 uint64_t ps;
1404
1405                 if (!lttng_chan->ops)
1406                         goto error;
1407                 ret = lttng_chan->ops->packet_size(config, buf, &ps);
1408                 if (ret < 0)
1409                         goto error;
1410                 return put_u64(ps, arg);
1411         }
1412         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1413         {
1414                 uint64_t si;
1415
1416                 if (!lttng_chan->ops)
1417                         goto error;
1418                 ret = lttng_chan->ops->stream_id(config, buf, &si);
1419                 if (ret < 0)
1420                         goto error;
1421                 return put_u64(si, arg);
1422         }
1423         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1424         {
1425                 uint64_t ts;
1426
1427                 if (!lttng_chan->ops)
1428                         goto error;
1429                 ret = lttng_chan->ops->current_timestamp(config, buf, &ts);
1430                 if (ret < 0)
1431                         goto error;
1432                 return put_u64(ts, arg);
1433         }
1434         default:
1435                 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1436                                 cmd, arg);
1437         }
1438
1439 error:
1440         return -ENOSYS;
1441 }
1442
1443 #ifdef CONFIG_COMPAT
1444 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1445                 unsigned int cmd, unsigned long arg)
1446 {
1447         struct lib_ring_buffer *buf = filp->private_data;
1448         struct channel *chan = buf->backend.chan;
1449         const struct lib_ring_buffer_config *config = &chan->backend.config;
1450         struct lttng_channel *lttng_chan = channel_get_private(chan);
1451         int ret;
1452
1453         if (atomic_read(&chan->record_disabled))
1454                 return -EIO;
1455
1456         switch (cmd) {
1457         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1458         {
1459                 uint64_t ts;
1460
1461                 if (!lttng_chan->ops)
1462                         goto error;
1463                 ret = lttng_chan->ops->timestamp_begin(config, buf, &ts);
1464                 if (ret < 0)
1465                         goto error;
1466                 return put_u64(ts, arg);
1467         }
1468         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1469         {
1470                 uint64_t ts;
1471
1472                 if (!lttng_chan->ops)
1473                         goto error;
1474                 ret = lttng_chan->ops->timestamp_end(config, buf, &ts);
1475                 if (ret < 0)
1476                         goto error;
1477                 return put_u64(ts, arg);
1478         }
1479         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1480         {
1481                 uint64_t ed;
1482
1483                 if (!lttng_chan->ops)
1484                         goto error;
1485                 ret = lttng_chan->ops->events_discarded(config, buf, &ed);
1486                 if (ret < 0)
1487                         goto error;
1488                 return put_u64(ed, arg);
1489         }
1490         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1491         {
1492                 uint64_t cs;
1493
1494                 if (!lttng_chan->ops)
1495                         goto error;
1496                 ret = lttng_chan->ops->content_size(config, buf, &cs);
1497                 if (ret < 0)
1498                         goto error;
1499                 return put_u64(cs, arg);
1500         }
1501         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1502         {
1503                 uint64_t ps;
1504
1505                 if (!lttng_chan->ops)
1506                         goto error;
1507                 ret = lttng_chan->ops->packet_size(config, buf, &ps);
1508                 if (ret < 0)
1509                         goto error;
1510                 return put_u64(ps, arg);
1511         }
1512         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1513         {
1514                 uint64_t si;
1515
1516                 if (!lttng_chan->ops)
1517                         goto error;
1518                 ret = lttng_chan->ops->stream_id(config, buf, &si);
1519                 if (ret < 0)
1520                         goto error;
1521                 return put_u64(si, arg);
1522         }
1523         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1524         {
1525                 uint64_t ts;
1526
1527                 if (!lttng_chan->ops)
1528                         goto error;
1529                 ret = lttng_chan->ops->current_timestamp(config, buf, &ts);
1530                 if (ret < 0)
1531                         goto error;
1532                 return put_u64(ts, arg);
1533         }
1534         default:
1535                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1536                                 cmd, arg);
1537         }
1538
1539 error:
1540         return -ENOSYS;
1541 }
1542 #endif /* CONFIG_COMPAT */
1543
1544 static void lttng_stream_override_ring_buffer_fops(void)
1545 {
1546         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1547         lttng_stream_ring_buffer_file_operations.open =
1548                 lib_ring_buffer_file_operations.open;
1549         lttng_stream_ring_buffer_file_operations.release =
1550                 lib_ring_buffer_file_operations.release;
1551         lttng_stream_ring_buffer_file_operations.poll =
1552                 lib_ring_buffer_file_operations.poll;
1553         lttng_stream_ring_buffer_file_operations.splice_read =
1554                 lib_ring_buffer_file_operations.splice_read;
1555         lttng_stream_ring_buffer_file_operations.mmap =
1556                 lib_ring_buffer_file_operations.mmap;
1557         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1558                 lttng_stream_ring_buffer_ioctl;
1559         lttng_stream_ring_buffer_file_operations.llseek =
1560                 lib_ring_buffer_file_operations.llseek;
1561 #ifdef CONFIG_COMPAT
1562         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1563                 lttng_stream_ring_buffer_compat_ioctl;
1564 #endif
1565 }
1566
1567 int __init lttng_abi_init(void)
1568 {
1569         int ret = 0;
1570
1571         wrapper_vmalloc_sync_all();
1572         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1573                                         &lttng_fops, NULL);
1574
1575         if (!lttng_proc_dentry) {
1576                 printk(KERN_ERR "Error creating LTTng control file\n");
1577                 ret = -ENOMEM;
1578                 goto error;
1579         }
1580         lttng_stream_override_ring_buffer_fops();
1581
1582 error:
1583         return ret;
1584 }
1585
1586 void __exit lttng_abi_exit(void)
1587 {
1588         if (lttng_proc_dentry)
1589                 remove_proc_entry("lttng", NULL);
1590 }