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         mutex_init(&metadata_stream->lock);
 845
 846         /*
 847          * Since life-time of metadata cache differs from that of
 848          * session, we need to keep our own reference on the transport.
 849          */
 850         if (!try_module_get(metadata_stream->transport->owner)) {
 851                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 852                 ret = -EINVAL;
 853                 goto notransport;
 854         }
 855
 856         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 857                         &lttng_metadata_ring_buffer_file_operations);
 858         if (ret < 0)
 859                 goto fd_error;
 860
 861         kref_get(&session->metadata_cache->refcount);
 862         list_add(&metadata_stream->list,
 863                 &session->metadata_cache->metadata_stream);
 864         return ret;
 865
 866 fd_error:
 867         module_put(metadata_stream->transport->owner);
 868 notransport:
 869         kfree(metadata_stream);
 870 nomem:
 871         channel->ops->buffer_read_close(buf);
 872         return ret;
 873 }
 874
 875 static
 876 int lttng_abi_create_event(struct file *channel_file,
 877                            struct lttng_kernel_event *event_param)
 878 {
 879         struct lttng_channel *channel = channel_file->private_data;
 880         struct lttng_event *event;
 881         int event_fd, ret;
 882         struct file *event_file;
 883
 884         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 885         switch (event_param->instrumentation) {
 886         case LTTNG_KERNEL_KRETPROBE:
 887                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 888                 break;
 889         case LTTNG_KERNEL_KPROBE:
 890                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 891                 break;
 892         case LTTNG_KERNEL_FUNCTION:
 893                 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 894                 break;
 895         default:
 896                 break;
 897         }
 898         switch (event_param->instrumentation) {
 899         default:
 900                 event_fd = get_unused_fd();
 901                 if (event_fd < 0) {
 902                         ret = event_fd;
 903                         goto fd_error;
 904                 }
 905                 event_file = anon_inode_getfile("[lttng_event]",
 906                                                 &lttng_event_fops,
 907                                                 NULL, O_RDWR);
 908                 if (IS_ERR(event_file)) {
 909                         ret = PTR_ERR(event_file);
 910                         goto file_error;
 911                 }
 912                 /*
 913                  * We tolerate no failure path after event creation. It
 914                  * will stay invariant for the rest of the session.
 915                  */
 916                 event = lttng_event_create(channel, event_param, NULL, NULL);
 917                 WARN_ON_ONCE(!event);
 918                 if (IS_ERR(event)) {
 919                         ret = PTR_ERR(event);
 920                         goto event_error;
 921                 }
 922                 event_file->private_data = event;
 923                 fd_install(event_fd, event_file);
 924                 /* The event holds a reference on the channel */
 925                 atomic_long_inc(&channel_file->f_count);
 926                 break;
 927         case LTTNG_KERNEL_SYSCALL:
 928                 /*
 929                  * Only all-syscall tracing supported for now.
 930                  */
 931                 if (event_param->name[0] != '\0')
 932                         return -EINVAL;
 933                 ret = lttng_syscalls_register(channel, NULL);
 934                 if (ret)
 935                         goto fd_error;
 936                 event_fd = 0;
 937                 break;
 938         }
 939         return event_fd;
 940
 941 event_error:
 942         fput(event_file);
 943 file_error:
 944         put_unused_fd(event_fd);
 945 fd_error:
 946         return ret;
 947 }
 948
 949 /**
 950  *      lttng_channel_ioctl - lttng syscall through ioctl
 951  *
 952  *      @file: the file
 953  *      @cmd: the command
 954  *      @arg: command arg
 955  *
 956  *      This ioctl implements lttng commands:
 957  *      LTTNG_KERNEL_STREAM
 958  *              Returns an event stream file descriptor or failure.
 959  *              (typically, one event stream records events from one CPU)
 960  *      LTTNG_KERNEL_EVENT
 961  *              Returns an event file descriptor or failure.
 962  *      LTTNG_KERNEL_CONTEXT
 963  *              Prepend a context field to each event in the channel
 964  *      LTTNG_KERNEL_ENABLE
 965  *              Enable recording for events in this channel (weak enable)
 966  *      LTTNG_KERNEL_DISABLE
 967  *              Disable recording for events in this channel (strong disable)
 968  *
 969  * Channel and event file descriptors also hold a reference on the session.
 970  */
 971 static
 972 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 973 {
 974         struct lttng_channel *channel = file->private_data;
 975
 976         switch (cmd) {
 977         case LTTNG_KERNEL_OLD_STREAM:
 978         case LTTNG_KERNEL_STREAM:
 979                 return lttng_abi_open_stream(file);
 980         case LTTNG_KERNEL_OLD_EVENT:
 981         {
 982                 struct lttng_kernel_event *uevent_param;
 983                 struct lttng_kernel_old_event *old_uevent_param;
 984                 int ret;
 985
 986                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
 987                                 GFP_KERNEL);
 988                 if (!uevent_param) {
 989                         ret = -ENOMEM;
 990                         goto old_event_end;
 991                 }
 992                 old_uevent_param = kmalloc(
 993                                 sizeof(struct lttng_kernel_old_event),
 994                                 GFP_KERNEL);
 995                 if (!old_uevent_param) {
 996                         ret = -ENOMEM;
 997                         goto old_event_error_free_param;
 998                 }
 999                 if (copy_from_user(old_uevent_param,
1000                                 (struct lttng_kernel_old_event __user *) arg,
1001                                 sizeof(struct lttng_kernel_old_event))) {
1002                         ret = -EFAULT;
1003                         goto old_event_error_free_old_param;
1004                 }
1005
1006                 memcpy(uevent_param->name, old_uevent_param->name,
1007                                 sizeof(uevent_param->name));
1008                 uevent_param->instrumentation =
1009                         old_uevent_param->instrumentation;
1010
1011                 switch (old_uevent_param->instrumentation) {
1012                 case LTTNG_KERNEL_KPROBE:
1013                         uevent_param->u.kprobe.addr =
1014                                 old_uevent_param->u.kprobe.addr;
1015                         uevent_param->u.kprobe.offset =
1016                                 old_uevent_param->u.kprobe.offset;
1017                         memcpy(uevent_param->u.kprobe.symbol_name,
1018                                 old_uevent_param->u.kprobe.symbol_name,
1019                                 sizeof(uevent_param->u.kprobe.symbol_name));
1020                         break;
1021                 case LTTNG_KERNEL_KRETPROBE:
1022                         uevent_param->u.kretprobe.addr =
1023                                 old_uevent_param->u.kretprobe.addr;
1024                         uevent_param->u.kretprobe.offset =
1025                                 old_uevent_param->u.kretprobe.offset;
1026                         memcpy(uevent_param->u.kretprobe.symbol_name,
1027                                 old_uevent_param->u.kretprobe.symbol_name,
1028                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1029                         break;
1030                 case LTTNG_KERNEL_FUNCTION:
1031                         memcpy(uevent_param->u.ftrace.symbol_name,
1032                                         old_uevent_param->u.ftrace.symbol_name,
1033                                         sizeof(uevent_param->u.ftrace.symbol_name));
1034                         break;
1035                 default:
1036                         break;
1037                 }
1038                 ret = lttng_abi_create_event(file, uevent_param);
1039
1040 old_event_error_free_old_param:
1041                 kfree(old_uevent_param);
1042 old_event_error_free_param:
1043                 kfree(uevent_param);
1044 old_event_end:
1045                 return ret;
1046         }
1047         case LTTNG_KERNEL_EVENT:
1048         {
1049                 struct lttng_kernel_event uevent_param;
1050
1051                 if (copy_from_user(&uevent_param,
1052                                 (struct lttng_kernel_event __user *) arg,
1053                                 sizeof(uevent_param)))
1054                         return -EFAULT;
1055                 return lttng_abi_create_event(file, &uevent_param);
1056         }
1057         case LTTNG_KERNEL_OLD_CONTEXT:
1058         {
1059                 struct lttng_kernel_context *ucontext_param;
1060                 struct lttng_kernel_old_context *old_ucontext_param;
1061                 int ret;
1062
1063                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1064                                 GFP_KERNEL);
1065                 if (!ucontext_param) {
1066                         ret = -ENOMEM;
1067                         goto old_ctx_end;
1068                 }
1069                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1070                                 GFP_KERNEL);
1071                 if (!old_ucontext_param) {
1072                         ret = -ENOMEM;
1073                         goto old_ctx_error_free_param;
1074                 }
1075
1076                 if (copy_from_user(old_ucontext_param,
1077                                 (struct lttng_kernel_old_context __user *) arg,
1078                                 sizeof(struct lttng_kernel_old_context))) {
1079                         ret = -EFAULT;
1080                         goto old_ctx_error_free_old_param;
1081                 }
1082                 ucontext_param->ctx = old_ucontext_param->ctx;
1083                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1084                                 sizeof(ucontext_param->padding));
1085                 /* only type that uses the union */
1086                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1087                         ucontext_param->u.perf_counter.type =
1088                                 old_ucontext_param->u.perf_counter.type;
1089                         ucontext_param->u.perf_counter.config =
1090                                 old_ucontext_param->u.perf_counter.config;
1091                         memcpy(ucontext_param->u.perf_counter.name,
1092                                 old_ucontext_param->u.perf_counter.name,
1093                                 sizeof(ucontext_param->u.perf_counter.name));
1094                 }
1095
1096                 ret = lttng_abi_add_context(file,
1097                                 ucontext_param,
1098                                 &channel->ctx, channel->session);
1099
1100 old_ctx_error_free_old_param:
1101                 kfree(old_ucontext_param);
1102 old_ctx_error_free_param:
1103                 kfree(ucontext_param);
1104 old_ctx_end:
1105                 return ret;
1106         }
1107         case LTTNG_KERNEL_CONTEXT:
1108         {
1109                 struct lttng_kernel_context ucontext_param;
1110
1111                 if (copy_from_user(&ucontext_param,
1112                                 (struct lttng_kernel_context __user *) arg,
1113                                 sizeof(ucontext_param)))
1114                         return -EFAULT;
1115                 return lttng_abi_add_context(file,
1116                                 &ucontext_param,
1117                                 &channel->ctx, channel->session);
1118         }
1119         case LTTNG_KERNEL_OLD_ENABLE:
1120         case LTTNG_KERNEL_ENABLE:
1121                 return lttng_channel_enable(channel);
1122         case LTTNG_KERNEL_OLD_DISABLE:
1123         case LTTNG_KERNEL_DISABLE:
1124                 return lttng_channel_disable(channel);
1125         default:
1126                 return -ENOIOCTLCMD;
1127         }
1128
1129 }
1130
1131 /**
1132  *      lttng_metadata_ioctl - lttng syscall through ioctl
1133  *
1134  *      @file: the file
1135  *      @cmd: the command
1136  *      @arg: command arg
1137  *
1138  *      This ioctl implements lttng commands:
1139  *      LTTNG_KERNEL_STREAM
1140  *              Returns an event stream file descriptor or failure.
1141  *
1142  * Channel and event file descriptors also hold a reference on the session.
1143  */
1144 static
1145 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1146 {
1147         switch (cmd) {
1148         case LTTNG_KERNEL_OLD_STREAM:
1149         case LTTNG_KERNEL_STREAM:
1150                 return lttng_abi_open_metadata_stream(file);
1151         default:
1152                 return -ENOIOCTLCMD;
1153         }
1154 }
1155
1156 /**
1157  *      lttng_channel_poll - lttng stream addition/removal monitoring
1158  *
1159  *      @file: the file
1160  *      @wait: poll table
1161  */
1162 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1163 {
1164         struct lttng_channel *channel = file->private_data;
1165         unsigned int mask = 0;
1166
1167         if (file->f_mode & FMODE_READ) {
1168                 poll_wait_set_exclusive(wait);
1169                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1170                           wait);
1171
1172                 if (channel->ops->is_disabled(channel->chan))
1173                         return POLLERR;
1174                 if (channel->ops->is_finalized(channel->chan))
1175                         return POLLHUP;
1176                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1177                         return POLLIN | POLLRDNORM;
1178                 return 0;
1179         }
1180         return mask;
1181
1182 }
1183
1184 static
1185 int lttng_channel_release(struct inode *inode, struct file *file)
1186 {
1187         struct lttng_channel *channel = file->private_data;
1188
1189         if (channel)
1190                 fput(channel->session->file);
1191         return 0;
1192 }
1193
1194 static
1195 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1196 {
1197         struct lttng_channel *channel = file->private_data;
1198
1199         if (channel) {
1200                 lttng_metadata_channel_destroy(channel);
1201                 fput(channel->session->file);
1202         }
1203
1204         return 0;
1205 }
1206
1207 static const struct file_operations lttng_channel_fops = {
1208         .owner = THIS_MODULE,
1209         .release = lttng_channel_release,
1210         .poll = lttng_channel_poll,
1211         .unlocked_ioctl = lttng_channel_ioctl,
1212 #ifdef CONFIG_COMPAT
1213         .compat_ioctl = lttng_channel_ioctl,
1214 #endif
1215 };
1216
1217 static const struct file_operations lttng_metadata_fops = {
1218         .owner = THIS_MODULE,
1219         .release = lttng_metadata_channel_release,
1220         .unlocked_ioctl = lttng_metadata_ioctl,
1221 #ifdef CONFIG_COMPAT
1222         .compat_ioctl = lttng_metadata_ioctl,
1223 #endif
1224 };
1225
1226 /**
1227  *      lttng_event_ioctl - lttng syscall through ioctl
1228  *
1229  *      @file: the file
1230  *      @cmd: the command
1231  *      @arg: command arg
1232  *
1233  *      This ioctl implements lttng commands:
1234  *      LTTNG_KERNEL_CONTEXT
1235  *              Prepend a context field to each record of this event
1236  *      LTTNG_KERNEL_ENABLE
1237  *              Enable recording for this event (weak enable)
1238  *      LTTNG_KERNEL_DISABLE
1239  *              Disable recording for this event (strong disable)
1240  */
1241 static
1242 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1243 {
1244         struct lttng_event *event = file->private_data;
1245
1246         switch (cmd) {
1247         case LTTNG_KERNEL_OLD_CONTEXT:
1248         {
1249                 struct lttng_kernel_context *ucontext_param;
1250                 struct lttng_kernel_old_context *old_ucontext_param;
1251                 int ret;
1252
1253                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1254                                 GFP_KERNEL);
1255                 if (!ucontext_param) {
1256                         ret = -ENOMEM;
1257                         goto old_ctx_end;
1258                 }
1259                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1260                                 GFP_KERNEL);
1261                 if (!old_ucontext_param) {
1262                         ret = -ENOMEM;
1263                         goto old_ctx_error_free_param;
1264                 }
1265
1266                 if (copy_from_user(old_ucontext_param,
1267                                         (struct lttng_kernel_old_context __user *) arg,
1268                                         sizeof(struct lttng_kernel_old_context))) {
1269                         ret = -EFAULT;
1270                         goto old_ctx_error_free_old_param;
1271                 }
1272                 ucontext_param->ctx = old_ucontext_param->ctx;
1273                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1274                                 sizeof(ucontext_param->padding));
1275                 /* only type that uses the union */
1276                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1277                         ucontext_param->u.perf_counter.type =
1278                                 old_ucontext_param->u.perf_counter.type;
1279                         ucontext_param->u.perf_counter.config =
1280                                 old_ucontext_param->u.perf_counter.config;
1281                         memcpy(ucontext_param->u.perf_counter.name,
1282                                         old_ucontext_param->u.perf_counter.name,
1283                                         sizeof(ucontext_param->u.perf_counter.name));
1284                 }
1285
1286                 ret = lttng_abi_add_context(file,
1287                                 ucontext_param,
1288                                 &event->ctx, event->chan->session);
1289
1290 old_ctx_error_free_old_param:
1291                 kfree(old_ucontext_param);
1292 old_ctx_error_free_param:
1293                 kfree(ucontext_param);
1294 old_ctx_end:
1295                 return ret;
1296         }
1297         case LTTNG_KERNEL_CONTEXT:
1298         {
1299                 struct lttng_kernel_context ucontext_param;
1300
1301                 if (copy_from_user(&ucontext_param,
1302                                         (struct lttng_kernel_context __user *) arg,
1303                                         sizeof(ucontext_param)))
1304                         return -EFAULT;
1305                 return lttng_abi_add_context(file,
1306                                 &ucontext_param,
1307                                 &event->ctx, event->chan->session);
1308         }
1309         case LTTNG_KERNEL_OLD_ENABLE:
1310         case LTTNG_KERNEL_ENABLE:
1311                 return lttng_event_enable(event);
1312         case LTTNG_KERNEL_OLD_DISABLE:
1313         case LTTNG_KERNEL_DISABLE:
1314                 return lttng_event_disable(event);
1315         default:
1316                 return -ENOIOCTLCMD;
1317         }
1318 }
1319
1320 static
1321 int lttng_event_release(struct inode *inode, struct file *file)
1322 {
1323         struct lttng_event *event = file->private_data;
1324
1325         if (event)
1326                 fput(event->chan->file);
1327         return 0;
1328 }
1329
1330 /* TODO: filter control ioctl */
1331 static const struct file_operations lttng_event_fops = {
1332         .owner = THIS_MODULE,
1333         .release = lttng_event_release,
1334         .unlocked_ioctl = lttng_event_ioctl,
1335 #ifdef CONFIG_COMPAT
1336         .compat_ioctl = lttng_event_ioctl,
1337 #endif
1338 };
1339
1340 static int put_u64(uint64_t val, unsigned long arg)
1341 {
1342         return put_user(val, (uint64_t __user *) arg);
1343 }
1344
1345 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1346                 unsigned int cmd, unsigned long arg)
1347 {
1348         struct lib_ring_buffer *buf = filp->private_data;
1349         struct channel *chan = buf->backend.chan;
1350         const struct lib_ring_buffer_config *config = &chan->backend.config;
1351         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1352         int ret;
1353
1354         if (atomic_read(&chan->record_disabled))
1355                 return -EIO;
1356
1357         switch (cmd) {
1358         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1359         {
1360                 uint64_t ts;
1361
1362                 ret = ops->timestamp_begin(config, buf, &ts);
1363                 if (ret < 0)
1364                         goto error;
1365                 return put_u64(ts, arg);
1366         }
1367         case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1368         {
1369                 uint64_t ts;
1370
1371                 ret = ops->timestamp_end(config, buf, &ts);
1372                 if (ret < 0)
1373                         goto error;
1374                 return put_u64(ts, arg);
1375         }
1376         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1377         {
1378                 uint64_t ed;
1379
1380                 ret = ops->events_discarded(config, buf, &ed);
1381                 if (ret < 0)
1382                         goto error;
1383                 return put_u64(ed, arg);
1384         }
1385         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1386         {
1387                 uint64_t cs;
1388
1389                 ret = ops->content_size(config, buf, &cs);
1390                 if (ret < 0)
1391                         goto error;
1392                 return put_u64(cs, arg);
1393         }
1394         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1395         {
1396                 uint64_t ps;
1397
1398                 ret = ops->packet_size(config, buf, &ps);
1399                 if (ret < 0)
1400                         goto error;
1401                 return put_u64(ps, arg);
1402         }
1403         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1404         {
1405                 uint64_t si;
1406
1407                 ret = ops->stream_id(config, buf, &si);
1408                 if (ret < 0)
1409                         goto error;
1410                 return put_u64(si, arg);
1411         }
1412         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1413         {
1414                 uint64_t ts;
1415
1416                 ret = ops->current_timestamp(config, buf, &ts);
1417                 if (ret < 0)
1418                         goto error;
1419                 return put_u64(ts, arg);
1420         }
1421         default:
1422                 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1423                                 cmd, arg);
1424         }
1425
1426 error:
1427         return -ENOSYS;
1428 }
1429
1430 #ifdef CONFIG_COMPAT
1431 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1432                 unsigned int cmd, unsigned long arg)
1433 {
1434         struct lib_ring_buffer *buf = filp->private_data;
1435         struct channel *chan = buf->backend.chan;
1436         const struct lib_ring_buffer_config *config = &chan->backend.config;
1437         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1438         int ret;
1439
1440         if (atomic_read(&chan->record_disabled))
1441                 return -EIO;
1442
1443         switch (cmd) {
1444         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1445         {
1446                 uint64_t ts;
1447
1448                 ret = ops->timestamp_begin(config, buf, &ts);
1449                 if (ret < 0)
1450                         goto error;
1451                 return put_u64(ts, arg);
1452         }
1453         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1454         {
1455                 uint64_t ts;
1456
1457                 ret = ops->timestamp_end(config, buf, &ts);
1458                 if (ret < 0)
1459                         goto error;
1460                 return put_u64(ts, arg);
1461         }
1462         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1463         {
1464                 uint64_t ed;
1465
1466                 ret = ops->events_discarded(config, buf, &ed);
1467                 if (ret < 0)
1468                         goto error;
1469                 return put_u64(ed, arg);
1470         }
1471         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1472         {
1473                 uint64_t cs;
1474
1475                 ret = ops->content_size(config, buf, &cs);
1476                 if (ret < 0)
1477                         goto error;
1478                 return put_u64(cs, arg);
1479         }
1480         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1481         {
1482                 uint64_t ps;
1483
1484                 ret = ops->packet_size(config, buf, &ps);
1485                 if (ret < 0)
1486                         goto error;
1487                 return put_u64(ps, arg);
1488         }
1489         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1490         {
1491                 uint64_t si;
1492
1493                 ret = ops->stream_id(config, buf, &si);
1494                 if (ret < 0)
1495                         goto error;
1496                 return put_u64(si, arg);
1497         }
1498         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1499         {
1500                 uint64_t ts;
1501
1502                 ret = ops->current_timestamp(config, buf, &ts);
1503                 if (ret < 0)
1504                         goto error;
1505                 return put_u64(ts, arg);
1506         }
1507         default:
1508                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1509                                 cmd, arg);
1510         }
1511
1512 error:
1513         return -ENOSYS;
1514 }
1515 #endif /* CONFIG_COMPAT */
1516
1517 static void lttng_stream_override_ring_buffer_fops(void)
1518 {
1519         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1520         lttng_stream_ring_buffer_file_operations.open =
1521                 lib_ring_buffer_file_operations.open;
1522         lttng_stream_ring_buffer_file_operations.release =
1523                 lib_ring_buffer_file_operations.release;
1524         lttng_stream_ring_buffer_file_operations.poll =
1525                 lib_ring_buffer_file_operations.poll;
1526         lttng_stream_ring_buffer_file_operations.splice_read =
1527                 lib_ring_buffer_file_operations.splice_read;
1528         lttng_stream_ring_buffer_file_operations.mmap =
1529                 lib_ring_buffer_file_operations.mmap;
1530         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1531                 lttng_stream_ring_buffer_ioctl;
1532         lttng_stream_ring_buffer_file_operations.llseek =
1533                 lib_ring_buffer_file_operations.llseek;
1534 #ifdef CONFIG_COMPAT
1535         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1536                 lttng_stream_ring_buffer_compat_ioctl;
1537 #endif
1538 }
1539
1540 int __init lttng_abi_init(void)
1541 {
1542         int ret = 0;
1543
1544         wrapper_vmalloc_sync_all();
1545         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1546                                         &lttng_fops, NULL);
1547
1548         if (!lttng_proc_dentry) {
1549                 printk(KERN_ERR "Error creating LTTng control file\n");
1550                 ret = -ENOMEM;
1551                 goto error;
1552         }
1553         lttng_stream_override_ring_buffer_fops();
1554
1555 error:
1556         return ret;
1557 }
1558
1559 /* No __exit annotation because used by init error path too. */
1560 void lttng_abi_exit(void)
1561 {
1562         if (lttng_proc_dentry)
1563                 remove_proc_entry("lttng", NULL);
1564 }