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                 mutex_lock(&stream->metadata_cache->lock);
 545                 if (stream->metadata_cache->metadata_written >
 546                                 stream->metadata_out)
 547                         mask |= POLLIN;
 548                 mutex_unlock(&stream->metadata_cache->lock);
 549         }
 550
 551         return mask;
 552 }
 553
 554 static
 555 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 556                 unsigned int cmd, unsigned long arg)
 557 {
 558         struct lttng_metadata_stream *stream = filp->private_data;
 559
 560         stream->metadata_out = stream->metadata_in;
 561 }
 562
 563 static
 564 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 565                 unsigned int cmd, unsigned long arg)
 566 {
 567         int ret;
 568         struct lttng_metadata_stream *stream = filp->private_data;
 569         struct lib_ring_buffer *buf = stream->priv;
 570
 571         switch (cmd) {
 572         case RING_BUFFER_GET_NEXT_SUBBUF:
 573         {
 574                 struct lttng_metadata_stream *stream = filp->private_data;
 575                 struct lib_ring_buffer *buf = stream->priv;
 576                 struct channel *chan = buf->backend.chan;
 577
 578                 ret = lttng_metadata_output_channel(stream, chan);
 579                 if (ret > 0) {
 580                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 581                         ret = 0;
 582                 } else if (ret < 0)
 583                         goto err;
 584                 break;
 585         }
 586         case RING_BUFFER_GET_SUBBUF:
 587         {
 588                 /*
 589                  * Random access is not allowed for metadata channel.
 590                  */
 591                 return -ENOSYS;
 592         }
 593         case RING_BUFFER_FLUSH:
 594         {
 595                 struct lttng_metadata_stream *stream = filp->private_data;
 596                 struct lib_ring_buffer *buf = stream->priv;
 597                 struct channel *chan = buf->backend.chan;
 598
 599                 /*
 600                  * Before doing the actual ring buffer flush, write up to one
 601                  * packet of metadata in the ring buffer.
 602                  */
 603                 ret = lttng_metadata_output_channel(stream, chan);
 604                 if (ret < 0)
 605                         goto err;
 606                 break;
 607         }
 608         default:
 609                 break;
 610         }
 611         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 612
 613         /* Performing lib ring buffer ioctl after our own. */
 614         ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
 615         if (ret < 0)
 616                 goto err;
 617
 618         switch (cmd) {
 619         case RING_BUFFER_PUT_NEXT_SUBBUF:
 620         {
 621                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 622                                 cmd, arg);
 623                 break;
 624         }
 625         default:
 626                 break;
 627         }
 628 err:
 629         return ret;
 630 }
 631
 632 #ifdef CONFIG_COMPAT
 633 static
 634 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 635                 unsigned int cmd, unsigned long arg)
 636 {
 637         int ret;
 638         struct lttng_metadata_stream *stream = filp->private_data;
 639         struct lib_ring_buffer *buf = stream->priv;
 640
 641         switch (cmd) {
 642         case RING_BUFFER_GET_NEXT_SUBBUF:
 643         {
 644                 struct lttng_metadata_stream *stream = filp->private_data;
 645                 struct lib_ring_buffer *buf = stream->priv;
 646                 struct channel *chan = buf->backend.chan;
 647
 648                 ret = lttng_metadata_output_channel(stream, chan);
 649                 if (ret > 0) {
 650                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 651                         ret = 0;
 652                 } else if (ret < 0)
 653                         goto err;
 654                 break;
 655         }
 656         case RING_BUFFER_GET_SUBBUF:
 657         {
 658                 /*
 659                  * Random access is not allowed for metadata channel.
 660                  */
 661                 return -ENOSYS;
 662         }
 663         default:
 664                 break;
 665         }
 666         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 667
 668         /* Performing lib ring buffer ioctl after our own. */
 669         ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
 670         if (ret < 0)
 671                 goto err;
 672
 673         switch (cmd) {
 674         case RING_BUFFER_PUT_NEXT_SUBBUF:
 675         {
 676                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 677                                 cmd, arg);
 678                 break;
 679         }
 680         default:
 681                 break;
 682         }
 683 err:
 684         return ret;
 685 }
 686 #endif
 687
 688 /*
 689  * This is not used by anonymous file descriptors. This code is left
 690  * there if we ever want to implement an inode with open() operation.
 691  */
 692 static
 693 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 694 {
 695         struct lttng_metadata_stream *stream = inode->i_private;
 696         struct lib_ring_buffer *buf = stream->priv;
 697
 698         file->private_data = buf;
 699         /*
 700          * Since life-time of metadata cache differs from that of
 701          * session, we need to keep our own reference on the transport.
 702          */
 703         if (!try_module_get(stream->transport->owner)) {
 704                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 705                 return -EBUSY;
 706         }
 707         return lib_ring_buffer_open(inode, file, buf);
 708 }
 709
 710 static
 711 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
 712 {
 713         struct lttng_metadata_stream *stream = file->private_data;
 714         struct lib_ring_buffer *buf = stream->priv;
 715
 716         kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
 717         module_put(stream->transport->owner);
 718         return lib_ring_buffer_release(inode, file, buf);
 719 }
 720
 721 static
 722 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 723                 struct pipe_inode_info *pipe, size_t len,
 724                 unsigned int flags)
 725 {
 726         struct lttng_metadata_stream *stream = in->private_data;
 727         struct lib_ring_buffer *buf = stream->priv;
 728
 729         return lib_ring_buffer_splice_read(in, ppos, pipe, len,
 730                         flags, buf);
 731 }
 732
 733 static
 734 int lttng_metadata_ring_buffer_mmap(struct file *filp,
 735                 struct vm_area_struct *vma)
 736 {
 737         struct lttng_metadata_stream *stream = filp->private_data;
 738         struct lib_ring_buffer *buf = stream->priv;
 739
 740         return lib_ring_buffer_mmap(filp, vma, buf);
 741 }
 742
 743 static
 744 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
 745         .owner = THIS_MODULE,
 746         .open = lttng_metadata_ring_buffer_open,
 747         .release = lttng_metadata_ring_buffer_release,
 748         .poll = lttng_metadata_ring_buffer_poll,
 749         .splice_read = lttng_metadata_ring_buffer_splice_read,
 750         .mmap = lttng_metadata_ring_buffer_mmap,
 751         .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
 752         .llseek = vfs_lib_ring_buffer_no_llseek,
 753 #ifdef CONFIG_COMPAT
 754         .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
 755 #endif
 756 };
 757
 758 static
 759 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
 760                 const struct file_operations *fops)
 761 {
 762         int stream_fd, ret;
 763         struct file *stream_file;
 764
 765         stream_fd = get_unused_fd();
 766         if (stream_fd < 0) {
 767                 ret = stream_fd;
 768                 goto fd_error;
 769         }
 770         stream_file = anon_inode_getfile("[lttng_stream]", fops,
 771                         stream_priv, O_RDWR);
 772         if (IS_ERR(stream_file)) {
 773                 ret = PTR_ERR(stream_file);
 774                 goto file_error;
 775         }
 776         /*
 777          * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
 778          * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
 779          * file descriptor, so we set FMODE_PREAD here.
 780          */
 781         stream_file->f_mode |= FMODE_PREAD;
 782         fd_install(stream_fd, stream_file);
 783         /*
 784          * The stream holds a reference to the channel within the generic ring
 785          * buffer library, so no need to hold a refcount on the channel and
 786          * session files here.
 787          */
 788         return stream_fd;
 789
 790 file_error:
 791         put_unused_fd(stream_fd);
 792 fd_error:
 793         return ret;
 794 }
 795
 796 static
 797 int lttng_abi_open_stream(struct file *channel_file)
 798 {
 799         struct lttng_channel *channel = channel_file->private_data;
 800         struct lib_ring_buffer *buf;
 801         int ret;
 802         void *stream_priv;
 803
 804         buf = channel->ops->buffer_read_open(channel->chan);
 805         if (!buf)
 806                 return -ENOENT;
 807
 808         stream_priv = buf;
 809         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 810                         &lttng_stream_ring_buffer_file_operations);
 811         if (ret < 0)
 812                 goto fd_error;
 813
 814         return ret;
 815
 816 fd_error:
 817         channel->ops->buffer_read_close(buf);
 818         return ret;
 819 }
 820
 821 static
 822 int lttng_abi_open_metadata_stream(struct file *channel_file)
 823 {
 824         struct lttng_channel *channel = channel_file->private_data;
 825         struct lttng_session *session = channel->session;
 826         struct lib_ring_buffer *buf;
 827         int ret;
 828         struct lttng_metadata_stream *metadata_stream;
 829         void *stream_priv;
 830
 831         buf = channel->ops->buffer_read_open(channel->chan);
 832         if (!buf)
 833                 return -ENOENT;
 834
 835         metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
 836                         GFP_KERNEL);
 837         if (!metadata_stream) {
 838                 ret = -ENOMEM;
 839                 goto nomem;
 840         }
 841         metadata_stream->metadata_cache = session->metadata_cache;
 842         init_waitqueue_head(&metadata_stream->read_wait);
 843         metadata_stream->priv = buf;
 844         stream_priv = metadata_stream;
 845         metadata_stream->transport = channel->transport;
 846
 847         /*
 848          * Since life-time of metadata cache differs from that of
 849          * session, we need to keep our own reference on the transport.
 850          */
 851         if (!try_module_get(metadata_stream->transport->owner)) {
 852                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 853                 ret = -EINVAL;
 854                 goto notransport;
 855         }
 856
 857         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 858                         &lttng_metadata_ring_buffer_file_operations);
 859         if (ret < 0)
 860                 goto fd_error;
 861
 862         kref_get(&session->metadata_cache->refcount);
 863         list_add(&metadata_stream->list,
 864                 &session->metadata_cache->metadata_stream);
 865         return ret;
 866
 867 fd_error:
 868         module_put(metadata_stream->transport->owner);
 869 notransport:
 870         kfree(metadata_stream);
 871 nomem:
 872         channel->ops->buffer_read_close(buf);
 873         return ret;
 874 }
 875
 876 static
 877 int lttng_abi_create_event(struct file *channel_file,
 878                            struct lttng_kernel_event *event_param)
 879 {
 880         struct lttng_channel *channel = channel_file->private_data;
 881         struct lttng_event *event;
 882         int event_fd, ret;
 883         struct file *event_file;
 884
 885         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 886         switch (event_param->instrumentation) {
 887         case LTTNG_KERNEL_KRETPROBE:
 888                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 889                 break;
 890         case LTTNG_KERNEL_KPROBE:
 891                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 892                 break;
 893         case LTTNG_KERNEL_FUNCTION:
 894                 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 895                 break;
 896         default:
 897                 break;
 898         }
 899         switch (event_param->instrumentation) {
 900         default:
 901                 event_fd = get_unused_fd();
 902                 if (event_fd < 0) {
 903                         ret = event_fd;
 904                         goto fd_error;
 905                 }
 906                 event_file = anon_inode_getfile("[lttng_event]",
 907                                                 &lttng_event_fops,
 908                                                 NULL, O_RDWR);
 909                 if (IS_ERR(event_file)) {
 910                         ret = PTR_ERR(event_file);
 911                         goto file_error;
 912                 }
 913                 /*
 914                  * We tolerate no failure path after event creation. It
 915                  * will stay invariant for the rest of the session.
 916                  */
 917                 event = lttng_event_create(channel, event_param, NULL, NULL);
 918                 WARN_ON_ONCE(!event);
 919                 if (IS_ERR(event)) {
 920                         ret = PTR_ERR(event);
 921                         goto event_error;
 922                 }
 923                 event_file->private_data = event;
 924                 fd_install(event_fd, event_file);
 925                 /* The event holds a reference on the channel */
 926                 atomic_long_inc(&channel_file->f_count);
 927                 break;
 928         case LTTNG_KERNEL_SYSCALL:
 929                 /*
 930                  * Only all-syscall tracing supported for now.
 931                  */
 932                 if (event_param->name[0] != '\0')
 933                         return -EINVAL;
 934                 ret = lttng_syscalls_register(channel, NULL);
 935                 if (ret)
 936                         goto fd_error;
 937                 event_fd = 0;
 938                 break;
 939         }
 940         return event_fd;
 941
 942 event_error:
 943         fput(event_file);
 944 file_error:
 945         put_unused_fd(event_fd);
 946 fd_error:
 947         return ret;
 948 }
 949
 950 /**
 951  *      lttng_channel_ioctl - lttng syscall through ioctl
 952  *
 953  *      @file: the file
 954  *      @cmd: the command
 955  *      @arg: command arg
 956  *
 957  *      This ioctl implements lttng commands:
 958  *      LTTNG_KERNEL_STREAM
 959  *              Returns an event stream file descriptor or failure.
 960  *              (typically, one event stream records events from one CPU)
 961  *      LTTNG_KERNEL_EVENT
 962  *              Returns an event file descriptor or failure.
 963  *      LTTNG_KERNEL_CONTEXT
 964  *              Prepend a context field to each event in the channel
 965  *      LTTNG_KERNEL_ENABLE
 966  *              Enable recording for events in this channel (weak enable)
 967  *      LTTNG_KERNEL_DISABLE
 968  *              Disable recording for events in this channel (strong disable)
 969  *
 970  * Channel and event file descriptors also hold a reference on the session.
 971  */
 972 static
 973 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 974 {
 975         struct lttng_channel *channel = file->private_data;
 976
 977         switch (cmd) {
 978         case LTTNG_KERNEL_OLD_STREAM:
 979         case LTTNG_KERNEL_STREAM:
 980                 return lttng_abi_open_stream(file);
 981         case LTTNG_KERNEL_OLD_EVENT:
 982         {
 983                 struct lttng_kernel_event *uevent_param;
 984                 struct lttng_kernel_old_event *old_uevent_param;
 985                 int ret;
 986
 987                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
 988                                 GFP_KERNEL);
 989                 if (!uevent_param) {
 990                         ret = -ENOMEM;
 991                         goto old_event_end;
 992                 }
 993                 old_uevent_param = kmalloc(
 994                                 sizeof(struct lttng_kernel_old_event),
 995                                 GFP_KERNEL);
 996                 if (!old_uevent_param) {
 997                         ret = -ENOMEM;
 998                         goto old_event_error_free_param;
 999                 }
1000                 if (copy_from_user(old_uevent_param,
1001                                 (struct lttng_kernel_old_event __user *) arg,
1002                                 sizeof(struct lttng_kernel_old_event))) {
1003                         ret = -EFAULT;
1004                         goto old_event_error_free_old_param;
1005                 }
1006
1007                 memcpy(uevent_param->name, old_uevent_param->name,
1008                                 sizeof(uevent_param->name));
1009                 uevent_param->instrumentation =
1010                         old_uevent_param->instrumentation;
1011
1012                 switch (old_uevent_param->instrumentation) {
1013                 case LTTNG_KERNEL_KPROBE:
1014                         uevent_param->u.kprobe.addr =
1015                                 old_uevent_param->u.kprobe.addr;
1016                         uevent_param->u.kprobe.offset =
1017                                 old_uevent_param->u.kprobe.offset;
1018                         memcpy(uevent_param->u.kprobe.symbol_name,
1019                                 old_uevent_param->u.kprobe.symbol_name,
1020                                 sizeof(uevent_param->u.kprobe.symbol_name));
1021                         break;
1022                 case LTTNG_KERNEL_KRETPROBE:
1023                         uevent_param->u.kretprobe.addr =
1024                                 old_uevent_param->u.kretprobe.addr;
1025                         uevent_param->u.kretprobe.offset =
1026                                 old_uevent_param->u.kretprobe.offset;
1027                         memcpy(uevent_param->u.kretprobe.symbol_name,
1028                                 old_uevent_param->u.kretprobe.symbol_name,
1029                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1030                         break;
1031                 case LTTNG_KERNEL_FUNCTION:
1032                         memcpy(uevent_param->u.ftrace.symbol_name,
1033                                         old_uevent_param->u.ftrace.symbol_name,
1034                                         sizeof(uevent_param->u.ftrace.symbol_name));
1035                         break;
1036                 default:
1037                         break;
1038                 }
1039                 ret = lttng_abi_create_event(file, uevent_param);
1040
1041 old_event_error_free_old_param:
1042                 kfree(old_uevent_param);
1043 old_event_error_free_param:
1044                 kfree(uevent_param);
1045 old_event_end:
1046                 return ret;
1047         }
1048         case LTTNG_KERNEL_EVENT:
1049         {
1050                 struct lttng_kernel_event uevent_param;
1051
1052                 if (copy_from_user(&uevent_param,
1053                                 (struct lttng_kernel_event __user *) arg,
1054                                 sizeof(uevent_param)))
1055                         return -EFAULT;
1056                 return lttng_abi_create_event(file, &uevent_param);
1057         }
1058         case LTTNG_KERNEL_OLD_CONTEXT:
1059         {
1060                 struct lttng_kernel_context *ucontext_param;
1061                 struct lttng_kernel_old_context *old_ucontext_param;
1062                 int ret;
1063
1064                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1065                                 GFP_KERNEL);
1066                 if (!ucontext_param) {
1067                         ret = -ENOMEM;
1068                         goto old_ctx_end;
1069                 }
1070                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1071                                 GFP_KERNEL);
1072                 if (!old_ucontext_param) {
1073                         ret = -ENOMEM;
1074                         goto old_ctx_error_free_param;
1075                 }
1076
1077                 if (copy_from_user(old_ucontext_param,
1078                                 (struct lttng_kernel_old_context __user *) arg,
1079                                 sizeof(struct lttng_kernel_old_context))) {
1080                         ret = -EFAULT;
1081                         goto old_ctx_error_free_old_param;
1082                 }
1083                 ucontext_param->ctx = old_ucontext_param->ctx;
1084                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1085                                 sizeof(ucontext_param->padding));
1086                 /* only type that uses the union */
1087                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1088                         ucontext_param->u.perf_counter.type =
1089                                 old_ucontext_param->u.perf_counter.type;
1090                         ucontext_param->u.perf_counter.config =
1091                                 old_ucontext_param->u.perf_counter.config;
1092                         memcpy(ucontext_param->u.perf_counter.name,
1093                                 old_ucontext_param->u.perf_counter.name,
1094                                 sizeof(ucontext_param->u.perf_counter.name));
1095                 }
1096
1097                 ret = lttng_abi_add_context(file,
1098                                 ucontext_param,
1099                                 &channel->ctx, channel->session);
1100
1101 old_ctx_error_free_old_param:
1102                 kfree(old_ucontext_param);
1103 old_ctx_error_free_param:
1104                 kfree(ucontext_param);
1105 old_ctx_end:
1106                 return ret;
1107         }
1108         case LTTNG_KERNEL_CONTEXT:
1109         {
1110                 struct lttng_kernel_context ucontext_param;
1111
1112                 if (copy_from_user(&ucontext_param,
1113                                 (struct lttng_kernel_context __user *) arg,
1114                                 sizeof(ucontext_param)))
1115                         return -EFAULT;
1116                 return lttng_abi_add_context(file,
1117                                 &ucontext_param,
1118                                 &channel->ctx, channel->session);
1119         }
1120         case LTTNG_KERNEL_OLD_ENABLE:
1121         case LTTNG_KERNEL_ENABLE:
1122                 return lttng_channel_enable(channel);
1123         case LTTNG_KERNEL_OLD_DISABLE:
1124         case LTTNG_KERNEL_DISABLE:
1125                 return lttng_channel_disable(channel);
1126         default:
1127                 return -ENOIOCTLCMD;
1128         }
1129
1130 }
1131
1132 /**
1133  *      lttng_metadata_ioctl - lttng syscall through ioctl
1134  *
1135  *      @file: the file
1136  *      @cmd: the command
1137  *      @arg: command arg
1138  *
1139  *      This ioctl implements lttng commands:
1140  *      LTTNG_KERNEL_STREAM
1141  *              Returns an event stream file descriptor or failure.
1142  *
1143  * Channel and event file descriptors also hold a reference on the session.
1144  */
1145 static
1146 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1147 {
1148         switch (cmd) {
1149         case LTTNG_KERNEL_OLD_STREAM:
1150         case LTTNG_KERNEL_STREAM:
1151                 return lttng_abi_open_metadata_stream(file);
1152         default:
1153                 return -ENOIOCTLCMD;
1154         }
1155 }
1156
1157 /**
1158  *      lttng_channel_poll - lttng stream addition/removal monitoring
1159  *
1160  *      @file: the file
1161  *      @wait: poll table
1162  */
1163 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1164 {
1165         struct lttng_channel *channel = file->private_data;
1166         unsigned int mask = 0;
1167
1168         if (file->f_mode & FMODE_READ) {
1169                 poll_wait_set_exclusive(wait);
1170                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1171                           wait);
1172
1173                 if (channel->ops->is_disabled(channel->chan))
1174                         return POLLERR;
1175                 if (channel->ops->is_finalized(channel->chan))
1176                         return POLLHUP;
1177                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1178                         return POLLIN | POLLRDNORM;
1179                 return 0;
1180         }
1181         return mask;
1182
1183 }
1184
1185 static
1186 int lttng_channel_release(struct inode *inode, struct file *file)
1187 {
1188         struct lttng_channel *channel = file->private_data;
1189
1190         if (channel)
1191                 fput(channel->session->file);
1192         return 0;
1193 }
1194
1195 static
1196 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1197 {
1198         struct lttng_channel *channel = file->private_data;
1199
1200         if (channel) {
1201                 fput(channel->session->file);
1202                 lttng_metadata_channel_destroy(channel);
1203         }
1204
1205         return 0;
1206 }
1207
1208 static const struct file_operations lttng_channel_fops = {
1209         .owner = THIS_MODULE,
1210         .release = lttng_channel_release,
1211         .poll = lttng_channel_poll,
1212         .unlocked_ioctl = lttng_channel_ioctl,
1213 #ifdef CONFIG_COMPAT
1214         .compat_ioctl = lttng_channel_ioctl,
1215 #endif
1216 };
1217
1218 static const struct file_operations lttng_metadata_fops = {
1219         .owner = THIS_MODULE,
1220         .release = lttng_metadata_channel_release,
1221         .unlocked_ioctl = lttng_metadata_ioctl,
1222 #ifdef CONFIG_COMPAT
1223         .compat_ioctl = lttng_metadata_ioctl,
1224 #endif
1225 };
1226
1227 /**
1228  *      lttng_event_ioctl - lttng syscall through ioctl
1229  *
1230  *      @file: the file
1231  *      @cmd: the command
1232  *      @arg: command arg
1233  *
1234  *      This ioctl implements lttng commands:
1235  *      LTTNG_KERNEL_CONTEXT
1236  *              Prepend a context field to each record of this event
1237  *      LTTNG_KERNEL_ENABLE
1238  *              Enable recording for this event (weak enable)
1239  *      LTTNG_KERNEL_DISABLE
1240  *              Disable recording for this event (strong disable)
1241  */
1242 static
1243 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1244 {
1245         struct lttng_event *event = file->private_data;
1246
1247         switch (cmd) {
1248         case LTTNG_KERNEL_OLD_CONTEXT:
1249         {
1250                 struct lttng_kernel_context *ucontext_param;
1251                 struct lttng_kernel_old_context *old_ucontext_param;
1252                 int ret;
1253
1254                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1255                                 GFP_KERNEL);
1256                 if (!ucontext_param) {
1257                         ret = -ENOMEM;
1258                         goto old_ctx_end;
1259                 }
1260                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1261                                 GFP_KERNEL);
1262                 if (!old_ucontext_param) {
1263                         ret = -ENOMEM;
1264                         goto old_ctx_error_free_param;
1265                 }
1266
1267                 if (copy_from_user(old_ucontext_param,
1268                                         (struct lttng_kernel_old_context __user *) arg,
1269                                         sizeof(struct lttng_kernel_old_context))) {
1270                         ret = -EFAULT;
1271                         goto old_ctx_error_free_old_param;
1272                 }
1273                 ucontext_param->ctx = old_ucontext_param->ctx;
1274                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1275                                 sizeof(ucontext_param->padding));
1276                 /* only type that uses the union */
1277                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1278                         ucontext_param->u.perf_counter.type =
1279                                 old_ucontext_param->u.perf_counter.type;
1280                         ucontext_param->u.perf_counter.config =
1281                                 old_ucontext_param->u.perf_counter.config;
1282                         memcpy(ucontext_param->u.perf_counter.name,
1283                                         old_ucontext_param->u.perf_counter.name,
1284                                         sizeof(ucontext_param->u.perf_counter.name));
1285                 }
1286
1287                 ret = lttng_abi_add_context(file,
1288                                 ucontext_param,
1289                                 &event->ctx, event->chan->session);
1290
1291 old_ctx_error_free_old_param:
1292                 kfree(old_ucontext_param);
1293 old_ctx_error_free_param:
1294                 kfree(ucontext_param);
1295 old_ctx_end:
1296                 return ret;
1297         }
1298         case LTTNG_KERNEL_CONTEXT:
1299         {
1300                 struct lttng_kernel_context ucontext_param;
1301
1302                 if (copy_from_user(&ucontext_param,
1303                                         (struct lttng_kernel_context __user *) arg,
1304                                         sizeof(ucontext_param)))
1305                         return -EFAULT;
1306                 return lttng_abi_add_context(file,
1307                                 &ucontext_param,
1308                                 &event->ctx, event->chan->session);
1309         }
1310         case LTTNG_KERNEL_OLD_ENABLE:
1311         case LTTNG_KERNEL_ENABLE:
1312                 return lttng_event_enable(event);
1313         case LTTNG_KERNEL_OLD_DISABLE:
1314         case LTTNG_KERNEL_DISABLE:
1315                 return lttng_event_disable(event);
1316         default:
1317                 return -ENOIOCTLCMD;
1318         }
1319 }
1320
1321 static
1322 int lttng_event_release(struct inode *inode, struct file *file)
1323 {
1324         struct lttng_event *event = file->private_data;
1325
1326         if (event)
1327                 fput(event->chan->file);
1328         return 0;
1329 }
1330
1331 /* TODO: filter control ioctl */
1332 static const struct file_operations lttng_event_fops = {
1333         .owner = THIS_MODULE,
1334         .release = lttng_event_release,
1335         .unlocked_ioctl = lttng_event_ioctl,
1336 #ifdef CONFIG_COMPAT
1337         .compat_ioctl = lttng_event_ioctl,
1338 #endif
1339 };
1340
1341 static int put_u64(uint64_t val, unsigned long arg)
1342 {
1343         return put_user(val, (uint64_t __user *) arg);
1344 }
1345
1346 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1347                 unsigned int cmd, unsigned long arg)
1348 {
1349         struct lib_ring_buffer *buf = filp->private_data;
1350         struct channel *chan = buf->backend.chan;
1351         const struct lib_ring_buffer_config *config = &chan->backend.config;
1352         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1353         int ret;
1354
1355         if (atomic_read(&chan->record_disabled))
1356                 return -EIO;
1357
1358         switch (cmd) {
1359         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1360         {
1361                 uint64_t ts;
1362
1363                 ret = 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                 ret = ops->timestamp_end(config, buf, &ts);
1373                 if (ret < 0)
1374                         goto error;
1375                 return put_u64(ts, arg);
1376         }
1377         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1378         {
1379                 uint64_t ed;
1380
1381                 ret = ops->events_discarded(config, buf, &ed);
1382                 if (ret < 0)
1383                         goto error;
1384                 return put_u64(ed, arg);
1385         }
1386         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1387         {
1388                 uint64_t cs;
1389
1390                 ret = ops->content_size(config, buf, &cs);
1391                 if (ret < 0)
1392                         goto error;
1393                 return put_u64(cs, arg);
1394         }
1395         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1396         {
1397                 uint64_t ps;
1398
1399                 ret = ops->packet_size(config, buf, &ps);
1400                 if (ret < 0)
1401                         goto error;
1402                 return put_u64(ps, arg);
1403         }
1404         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1405         {
1406                 uint64_t si;
1407
1408                 ret = ops->stream_id(config, buf, &si);
1409                 if (ret < 0)
1410                         goto error;
1411                 return put_u64(si, arg);
1412         }
1413         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1414         {
1415                 uint64_t ts;
1416
1417                 ret = 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         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
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                 ret = ops->timestamp_begin(config, buf, &ts);
1450                 if (ret < 0)
1451                         goto error;
1452                 return put_u64(ts, arg);
1453         }
1454         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1455         {
1456                 uint64_t ts;
1457
1458                 ret = ops->timestamp_end(config, buf, &ts);
1459                 if (ret < 0)
1460                         goto error;
1461                 return put_u64(ts, arg);
1462         }
1463         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1464         {
1465                 uint64_t ed;
1466
1467                 ret = ops->events_discarded(config, buf, &ed);
1468                 if (ret < 0)
1469                         goto error;
1470                 return put_u64(ed, arg);
1471         }
1472         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1473         {
1474                 uint64_t cs;
1475
1476                 ret = ops->content_size(config, buf, &cs);
1477                 if (ret < 0)
1478                         goto error;
1479                 return put_u64(cs, arg);
1480         }
1481         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1482         {
1483                 uint64_t ps;
1484
1485                 ret = ops->packet_size(config, buf, &ps);
1486                 if (ret < 0)
1487                         goto error;
1488                 return put_u64(ps, arg);
1489         }
1490         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1491         {
1492                 uint64_t si;
1493
1494                 ret = ops->stream_id(config, buf, &si);
1495                 if (ret < 0)
1496                         goto error;
1497                 return put_u64(si, arg);
1498         }
1499         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1500         {
1501                 uint64_t ts;
1502
1503                 ret = ops->current_timestamp(config, buf, &ts);
1504                 if (ret < 0)
1505                         goto error;
1506                 return put_u64(ts, arg);
1507         }
1508         default:
1509                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1510                                 cmd, arg);
1511         }
1512
1513 error:
1514         return -ENOSYS;
1515 }
1516 #endif /* CONFIG_COMPAT */
1517
1518 static void lttng_stream_override_ring_buffer_fops(void)
1519 {
1520         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1521         lttng_stream_ring_buffer_file_operations.open =
1522                 lib_ring_buffer_file_operations.open;
1523         lttng_stream_ring_buffer_file_operations.release =
1524                 lib_ring_buffer_file_operations.release;
1525         lttng_stream_ring_buffer_file_operations.poll =
1526                 lib_ring_buffer_file_operations.poll;
1527         lttng_stream_ring_buffer_file_operations.splice_read =
1528                 lib_ring_buffer_file_operations.splice_read;
1529         lttng_stream_ring_buffer_file_operations.mmap =
1530                 lib_ring_buffer_file_operations.mmap;
1531         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1532                 lttng_stream_ring_buffer_ioctl;
1533         lttng_stream_ring_buffer_file_operations.llseek =
1534                 lib_ring_buffer_file_operations.llseek;
1535 #ifdef CONFIG_COMPAT
1536         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1537                 lttng_stream_ring_buffer_compat_ioctl;
1538 #endif
1539 }
1540
1541 int __init lttng_abi_init(void)
1542 {
1543         int ret = 0;
1544
1545         wrapper_vmalloc_sync_all();
1546         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1547                                         &lttng_fops, NULL);
1548
1549         if (!lttng_proc_dentry) {
1550                 printk(KERN_ERR "Error creating LTTng control file\n");
1551                 ret = -ENOMEM;
1552                 goto error;
1553         }
1554         lttng_stream_override_ring_buffer_fops();
1555
1556 error:
1557         return ret;
1558 }
1559
1560 /* No __exit annotation because used by init error path too. */
1561 void lttng_abi_exit(void)
1562 {
1563         if (lttng_proc_dentry)
1564                 remove_proc_entry("lttng", NULL);
1565 }