lttng-abi.c

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * lttng-abi.c
   4  *
   5  * LTTng ABI
   6  *
   7  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Mimic system calls for:
  10  * - session creation, returns a file descriptor or failure.
  11  *   - channel creation, returns a file descriptor or failure.
  12  *     - Operates on a session file descriptor
  13  *     - Takes all channel options as parameters.
  14  *   - stream get, returns a file descriptor or failure.
  15  *     - Operates on a channel file descriptor.
  16  *   - stream notifier get, returns a file descriptor or failure.
  17  *     - Operates on a channel file descriptor.
  18  *   - event creation, returns a file descriptor or failure.
  19  *     - Operates on a channel file descriptor
  20  *     - Takes an event name as parameter
  21  *     - Takes an instrumentation source as parameter
  22  *       - e.g. tracepoints, dynamic_probes...
  23  *     - Takes instrumentation source specific arguments.
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/anon_inodes.h>
  29 #include <linux/file.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/slab.h>
  32 #include <linux/err.h>
  33 #include <wrapper/vmalloc.h>    /* for wrapper_vmalloc_sync_mappings() */
  34 #include <wrapper/ringbuffer/vfs.h>
  35 #include <wrapper/ringbuffer/backend.h>
  36 #include <wrapper/ringbuffer/frontend.h>
  37 #include <wrapper/poll.h>
  38 #include <wrapper/file.h>
  39 #include <wrapper/kref.h>
  40 #include <lttng-string-utils.h>
  41 #include <lttng-abi.h>
  42 #include <lttng-abi-old.h>
  43 #include <lttng-events.h>
  44 #include <lttng-tracer.h>
  45 #include <lttng-tp-mempool.h>
  46 #include <lib/ringbuffer/frontend_types.h>
  47
  48 /*
  49  * This is LTTng's own personal way to create a system call as an external
  50  * module. We use ioctl() on /proc/lttng.
  51  */
  52
  53 static struct proc_dir_entry *lttng_proc_dentry;
  54
  55 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
  56 static const struct proc_ops lttng_proc_ops;
  57 #else
  58 static const struct file_operations lttng_proc_ops;
  59 #endif
  60
  61 static const struct file_operations lttng_session_fops;
  62 static const struct file_operations lttng_channel_fops;
  63 static const struct file_operations lttng_metadata_fops;
  64 static const struct file_operations lttng_event_fops;
  65 static struct file_operations lttng_stream_ring_buffer_file_operations;
  66
  67 static int put_u64(uint64_t val, unsigned long arg);
  68 static int put_u32(uint32_t val, unsigned long arg);
  69
  70 /*
  71  * Teardown management: opened file descriptors keep a refcount on the module,
  72  * so it can only exit when all file descriptors are closed.
  73  */
  74
  75 static
  76 int lttng_abi_create_session(void)
  77 {
  78         struct lttng_session *session;
  79         struct file *session_file;
  80         int session_fd, ret;
  81
  82         session = lttng_session_create();
  83         if (!session)
  84                 return -ENOMEM;
  85         session_fd = lttng_get_unused_fd();
  86         if (session_fd < 0) {
  87                 ret = session_fd;
  88                 goto fd_error;
  89         }
  90         session_file = anon_inode_getfile("[lttng_session]",
  91                                           &lttng_session_fops,
  92                                           session, O_RDWR);
  93         if (IS_ERR(session_file)) {
  94                 ret = PTR_ERR(session_file);
  95                 goto file_error;
  96         }
  97         session->file = session_file;
  98         fd_install(session_fd, session_file);
  99         return session_fd;
 100
 101 file_error:
 102         put_unused_fd(session_fd);
 103 fd_error:
 104         lttng_session_destroy(session);
 105         return ret;
 106 }
 107
 108 static
 109 int lttng_abi_tracepoint_list(void)
 110 {
 111         struct file *tracepoint_list_file;
 112         int file_fd, ret;
 113
 114         file_fd = lttng_get_unused_fd();
 115         if (file_fd < 0) {
 116                 ret = file_fd;
 117                 goto fd_error;
 118         }
 119
 120         tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
 121                                           &lttng_tracepoint_list_fops,
 122                                           NULL, O_RDWR);
 123         if (IS_ERR(tracepoint_list_file)) {
 124                 ret = PTR_ERR(tracepoint_list_file);
 125                 goto file_error;
 126         }
 127         ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
 128         if (ret < 0)
 129                 goto open_error;
 130         fd_install(file_fd, tracepoint_list_file);
 131         return file_fd;
 132
 133 open_error:
 134         fput(tracepoint_list_file);
 135 file_error:
 136         put_unused_fd(file_fd);
 137 fd_error:
 138         return ret;
 139 }
 140
 141 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 142 static inline
 143 int lttng_abi_syscall_list(void)
 144 {
 145         return -ENOSYS;
 146 }
 147 #else
 148 static
 149 int lttng_abi_syscall_list(void)
 150 {
 151         struct file *syscall_list_file;
 152         int file_fd, ret;
 153
 154         file_fd = lttng_get_unused_fd();
 155         if (file_fd < 0) {
 156                 ret = file_fd;
 157                 goto fd_error;
 158         }
 159
 160         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
 161                                           &lttng_syscall_list_fops,
 162                                           NULL, O_RDWR);
 163         if (IS_ERR(syscall_list_file)) {
 164                 ret = PTR_ERR(syscall_list_file);
 165                 goto file_error;
 166         }
 167         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
 168         if (ret < 0)
 169                 goto open_error;
 170         fd_install(file_fd, syscall_list_file);
 171         return file_fd;
 172
 173 open_error:
 174         fput(syscall_list_file);
 175 file_error:
 176         put_unused_fd(file_fd);
 177 fd_error:
 178         return ret;
 179 }
 180 #endif
 181
 182 static
 183 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
 184 {
 185         v->major = LTTNG_MODULES_MAJOR_VERSION;
 186         v->minor = LTTNG_MODULES_MINOR_VERSION;
 187         v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
 188 }
 189
 190 static
 191 void lttng_abi_tracer_abi_version(struct lttng_kernel_tracer_abi_version *v)
 192 {
 193         v->major = LTTNG_MODULES_ABI_MAJOR_VERSION;
 194         v->minor = LTTNG_MODULES_ABI_MINOR_VERSION;
 195 }
 196
 197 static
 198 long lttng_abi_add_context(struct file *file,
 199         struct lttng_kernel_context *context_param,
 200         struct lttng_ctx **ctx, struct lttng_session *session)
 201 {
 202
 203         if (session->been_active)
 204                 return -EPERM;
 205
 206         switch (context_param->ctx) {
 207         case LTTNG_KERNEL_CONTEXT_PID:
 208                 return lttng_add_pid_to_ctx(ctx);
 209         case LTTNG_KERNEL_CONTEXT_PRIO:
 210                 return lttng_add_prio_to_ctx(ctx);
 211         case LTTNG_KERNEL_CONTEXT_NICE:
 212                 return lttng_add_nice_to_ctx(ctx);
 213         case LTTNG_KERNEL_CONTEXT_VPID:
 214                 return lttng_add_vpid_to_ctx(ctx);
 215         case LTTNG_KERNEL_CONTEXT_TID:
 216                 return lttng_add_tid_to_ctx(ctx);
 217         case LTTNG_KERNEL_CONTEXT_VTID:
 218                 return lttng_add_vtid_to_ctx(ctx);
 219         case LTTNG_KERNEL_CONTEXT_PPID:
 220                 return lttng_add_ppid_to_ctx(ctx);
 221         case LTTNG_KERNEL_CONTEXT_VPPID:
 222                 return lttng_add_vppid_to_ctx(ctx);
 223         case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
 224                 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 225                 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
 226                                 context_param->u.perf_counter.config,
 227                                 context_param->u.perf_counter.name,
 228                                 ctx);
 229         case LTTNG_KERNEL_CONTEXT_PROCNAME:
 230                 return lttng_add_procname_to_ctx(ctx);
 231         case LTTNG_KERNEL_CONTEXT_HOSTNAME:
 232                 return lttng_add_hostname_to_ctx(ctx);
 233         case LTTNG_KERNEL_CONTEXT_CPU_ID:
 234                 return lttng_add_cpu_id_to_ctx(ctx);
 235         case LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE:
 236                 return lttng_add_interruptible_to_ctx(ctx);
 237         case LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE:
 238                 return lttng_add_need_reschedule_to_ctx(ctx);
 239         case LTTNG_KERNEL_CONTEXT_PREEMPTIBLE:
 240                 return lttng_add_preemptible_to_ctx(ctx);
 241         case LTTNG_KERNEL_CONTEXT_MIGRATABLE:
 242                 return lttng_add_migratable_to_ctx(ctx);
 243         case LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL:
 244         case LTTNG_KERNEL_CONTEXT_CALLSTACK_USER:
 245                 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
 246         default:
 247                 return -EINVAL;
 248         }
 249 }
 250
 251 /**
 252  *      lttng_ioctl - lttng syscall through ioctl
 253  *
 254  *      @file: the file
 255  *      @cmd: the command
 256  *      @arg: command arg
 257  *
 258  *      This ioctl implements lttng commands:
 259  *      LTTNG_KERNEL_SESSION
 260  *              Returns a LTTng trace session file descriptor
 261  *      LTTNG_KERNEL_TRACER_VERSION
 262  *              Returns the LTTng kernel tracer version
 263  *      LTTNG_KERNEL_TRACEPOINT_LIST
 264  *              Returns a file descriptor listing available tracepoints
 265  *      LTTNG_KERNEL_WAIT_QUIESCENT
 266  *              Returns after all previously running probes have completed
 267  *      LTTNG_KERNEL_TRACER_ABI_VERSION
 268  *              Returns the LTTng kernel tracer ABI version
 269  *
 270  * The returned session will be deleted when its file descriptor is closed.
 271  */
 272 static
 273 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 274 {
 275         switch (cmd) {
 276         case LTTNG_KERNEL_OLD_SESSION:
 277         case LTTNG_KERNEL_SESSION:
 278                 return lttng_abi_create_session();
 279         case LTTNG_KERNEL_OLD_TRACER_VERSION:
 280         {
 281                 struct lttng_kernel_tracer_version v;
 282                 struct lttng_kernel_old_tracer_version oldv;
 283                 struct lttng_kernel_old_tracer_version *uversion =
 284                         (struct lttng_kernel_old_tracer_version __user *) arg;
 285
 286                 lttng_abi_tracer_version(&v);
 287                 oldv.major = v.major;
 288                 oldv.minor = v.minor;
 289                 oldv.patchlevel = v.patchlevel;
 290
 291                 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
 292                         return -EFAULT;
 293                 return 0;
 294         }
 295         case LTTNG_KERNEL_TRACER_VERSION:
 296         {
 297                 struct lttng_kernel_tracer_version version;
 298                 struct lttng_kernel_tracer_version *uversion =
 299                         (struct lttng_kernel_tracer_version __user *) arg;
 300
 301                 lttng_abi_tracer_version(&version);
 302
 303                 if (copy_to_user(uversion, &version, sizeof(version)))
 304                         return -EFAULT;
 305                 return 0;
 306         }
 307         case LTTNG_KERNEL_TRACER_ABI_VERSION:
 308         {
 309                 struct lttng_kernel_tracer_abi_version version;
 310                 struct lttng_kernel_tracer_abi_version *uversion =
 311                         (struct lttng_kernel_tracer_abi_version __user *) arg;
 312
 313                 lttng_abi_tracer_abi_version(&version);
 314
 315                 if (copy_to_user(uversion, &version, sizeof(version)))
 316                         return -EFAULT;
 317                 return 0;
 318         }
 319         case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
 320         case LTTNG_KERNEL_TRACEPOINT_LIST:
 321                 return lttng_abi_tracepoint_list();
 322         case LTTNG_KERNEL_SYSCALL_LIST:
 323                 return lttng_abi_syscall_list();
 324         case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
 325         case LTTNG_KERNEL_WAIT_QUIESCENT:
 326                 synchronize_trace();
 327                 return 0;
 328         case LTTNG_KERNEL_OLD_CALIBRATE:
 329         {
 330                 struct lttng_kernel_old_calibrate __user *ucalibrate =
 331                         (struct lttng_kernel_old_calibrate __user *) arg;
 332                 struct lttng_kernel_old_calibrate old_calibrate;
 333                 struct lttng_kernel_calibrate calibrate;
 334                 int ret;
 335
 336                 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
 337                         return -EFAULT;
 338                 calibrate.type = old_calibrate.type;
 339                 ret = lttng_calibrate(&calibrate);
 340                 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
 341                         return -EFAULT;
 342                 return ret;
 343         }
 344         case LTTNG_KERNEL_CALIBRATE:
 345         {
 346                 struct lttng_kernel_calibrate __user *ucalibrate =
 347                         (struct lttng_kernel_calibrate __user *) arg;
 348                 struct lttng_kernel_calibrate calibrate;
 349                 int ret;
 350
 351                 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
 352                         return -EFAULT;
 353                 ret = lttng_calibrate(&calibrate);
 354                 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
 355                         return -EFAULT;
 356                 return ret;
 357         }
 358         default:
 359                 return -ENOIOCTLCMD;
 360         }
 361 }
 362
 363 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
 364 static const struct proc_ops lttng_proc_ops = {
 365         .proc_ioctl = lttng_ioctl,
 366 #ifdef CONFIG_COMPAT
 367         .proc_compat_ioctl = lttng_ioctl,
 368 #endif /* CONFIG_COMPAT */
 369 };
 370 #else
 371 static const struct file_operations lttng_proc_ops = {
 372         .owner = THIS_MODULE,
 373         .unlocked_ioctl = lttng_ioctl,
 374 #ifdef CONFIG_COMPAT
 375         .compat_ioctl = lttng_ioctl,
 376 #endif /* CONFIG_COMPAT */
 377 };
 378 #endif
 379
 380 static
 381 int lttng_abi_create_channel(struct file *session_file,
 382                              struct lttng_kernel_channel *chan_param,
 383                              enum channel_type channel_type)
 384 {
 385         struct lttng_session *session = session_file->private_data;
 386         const struct file_operations *fops = NULL;
 387         const char *transport_name;
 388         struct lttng_channel *chan;
 389         struct file *chan_file;
 390         int chan_fd;
 391         int ret = 0;
 392
 393         chan_fd = lttng_get_unused_fd();
 394         if (chan_fd < 0) {
 395                 ret = chan_fd;
 396                 goto fd_error;
 397         }
 398         switch (channel_type) {
 399         case PER_CPU_CHANNEL:
 400                 fops = &lttng_channel_fops;
 401                 break;
 402         case METADATA_CHANNEL:
 403                 fops = &lttng_metadata_fops;
 404                 break;
 405         }
 406
 407         chan_file = anon_inode_getfile("[lttng_channel]",
 408                                        fops,
 409                                        NULL, O_RDWR);
 410         if (IS_ERR(chan_file)) {
 411                 ret = PTR_ERR(chan_file);
 412                 goto file_error;
 413         }
 414         switch (channel_type) {
 415         case PER_CPU_CHANNEL:
 416                 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
 417                         transport_name = chan_param->overwrite ?
 418                                 "relay-overwrite" : "relay-discard";
 419                 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
 420                         transport_name = chan_param->overwrite ?
 421                                 "relay-overwrite-mmap" : "relay-discard-mmap";
 422                 } else {
 423                         return -EINVAL;
 424                 }
 425                 break;
 426         case METADATA_CHANNEL:
 427                 if (chan_param->output == LTTNG_KERNEL_SPLICE)
 428                         transport_name = "relay-metadata";
 429                 else if (chan_param->output == LTTNG_KERNEL_MMAP)
 430                         transport_name = "relay-metadata-mmap";
 431                 else
 432                         return -EINVAL;
 433                 break;
 434         default:
 435                 transport_name = "<unknown>";
 436                 break;
 437         }
 438         if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
 439                 ret = -EOVERFLOW;
 440                 goto refcount_error;
 441         }
 442         /*
 443          * We tolerate no failure path after channel creation. It will stay
 444          * invariant for the rest of the session.
 445          */
 446         chan = lttng_channel_create(session, transport_name, NULL,
 447                                   chan_param->subbuf_size,
 448                                   chan_param->num_subbuf,
 449                                   chan_param->switch_timer_interval,
 450                                   chan_param->read_timer_interval,
 451                                   channel_type);
 452         if (!chan) {
 453                 ret = -EINVAL;
 454                 goto chan_error;
 455         }
 456         chan->file = chan_file;
 457         chan_file->private_data = chan;
 458         fd_install(chan_fd, chan_file);
 459
 460         return chan_fd;
 461
 462 chan_error:
 463         atomic_long_dec(&session_file->f_count);
 464 refcount_error:
 465         fput(chan_file);
 466 file_error:
 467         put_unused_fd(chan_fd);
 468 fd_error:
 469         return ret;
 470 }
 471
 472 static
 473 int lttng_abi_session_set_name(struct lttng_session *session,
 474                 struct lttng_kernel_session_name *name)
 475 {
 476         size_t len;
 477
 478         len = strnlen(name->name, LTTNG_KERNEL_SESSION_NAME_LEN);
 479
 480         if (len == LTTNG_KERNEL_SESSION_NAME_LEN) {
 481                 /* Name is too long/malformed */
 482                 return -EINVAL;
 483         }
 484
 485         strcpy(session->name, name->name);
 486         return 0;
 487 }
 488
 489 static
 490 int lttng_abi_session_set_creation_time(struct lttng_session *session,
 491                 struct lttng_kernel_session_creation_time *time)
 492 {
 493         size_t len;
 494
 495         len = strnlen(time->iso8601, LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN);
 496
 497         if (len == LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN) {
 498                 /* Time is too long/malformed */
 499                 return -EINVAL;
 500         }
 501
 502         strcpy(session->creation_time, time->iso8601);
 503         return 0;
 504 }
 505
 506 /**
 507  *      lttng_session_ioctl - lttng session fd ioctl
 508  *
 509  *      @file: the file
 510  *      @cmd: the command
 511  *      @arg: command arg
 512  *
 513  *      This ioctl implements lttng commands:
 514  *      LTTNG_KERNEL_CHANNEL
 515  *              Returns a LTTng channel file descriptor
 516  *      LTTNG_KERNEL_ENABLE
 517  *              Enables tracing for a session (weak enable)
 518  *      LTTNG_KERNEL_DISABLE
 519  *              Disables tracing for a session (strong disable)
 520  *      LTTNG_KERNEL_METADATA
 521  *              Returns a LTTng metadata file descriptor
 522  *      LTTNG_KERNEL_SESSION_TRACK_PID
 523  *              Add PID to session tracker
 524  *      LTTNG_KERNEL_SESSION_UNTRACK_PID
 525  *              Remove PID from session tracker
 526  *
 527  * The returned channel will be deleted when its file descriptor is closed.
 528  */
 529 static
 530 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 531 {
 532         struct lttng_session *session = file->private_data;
 533         struct lttng_kernel_channel chan_param;
 534         struct lttng_kernel_old_channel old_chan_param;
 535
 536         switch (cmd) {
 537         case LTTNG_KERNEL_OLD_CHANNEL:
 538         {
 539                 if (copy_from_user(&old_chan_param,
 540                                 (struct lttng_kernel_old_channel __user *) arg,
 541                                 sizeof(struct lttng_kernel_old_channel)))
 542                         return -EFAULT;
 543                 chan_param.overwrite = old_chan_param.overwrite;
 544                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 545                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 546                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 547                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 548                 chan_param.output = old_chan_param.output;
 549
 550                 return lttng_abi_create_channel(file, &chan_param,
 551                                 PER_CPU_CHANNEL);
 552         }
 553         case LTTNG_KERNEL_CHANNEL:
 554         {
 555                 if (copy_from_user(&chan_param,
 556                                 (struct lttng_kernel_channel __user *) arg,
 557                                 sizeof(struct lttng_kernel_channel)))
 558                         return -EFAULT;
 559                 return lttng_abi_create_channel(file, &chan_param,
 560                                 PER_CPU_CHANNEL);
 561         }
 562         case LTTNG_KERNEL_OLD_SESSION_START:
 563         case LTTNG_KERNEL_OLD_ENABLE:
 564         case LTTNG_KERNEL_SESSION_START:
 565         case LTTNG_KERNEL_ENABLE:
 566                 return lttng_session_enable(session);
 567         case LTTNG_KERNEL_OLD_SESSION_STOP:
 568         case LTTNG_KERNEL_OLD_DISABLE:
 569         case LTTNG_KERNEL_SESSION_STOP:
 570         case LTTNG_KERNEL_DISABLE:
 571                 return lttng_session_disable(session);
 572         case LTTNG_KERNEL_OLD_METADATA:
 573         {
 574                 if (copy_from_user(&old_chan_param,
 575                                 (struct lttng_kernel_old_channel __user *) arg,
 576                                 sizeof(struct lttng_kernel_old_channel)))
 577                         return -EFAULT;
 578                 chan_param.overwrite = old_chan_param.overwrite;
 579                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 580                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 581                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 582                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 583                 chan_param.output = old_chan_param.output;
 584
 585                 return lttng_abi_create_channel(file, &chan_param,
 586                                 METADATA_CHANNEL);
 587         }
 588         case LTTNG_KERNEL_METADATA:
 589         {
 590                 if (copy_from_user(&chan_param,
 591                                         (struct lttng_kernel_channel __user *) arg,
 592                                         sizeof(struct lttng_kernel_channel)))
 593                         return -EFAULT;
 594                 return lttng_abi_create_channel(file, &chan_param,
 595                                 METADATA_CHANNEL);
 596         }
 597         case LTTNG_KERNEL_SESSION_TRACK_PID:
 598                 return lttng_session_track_pid(session, (int) arg);
 599         case LTTNG_KERNEL_SESSION_UNTRACK_PID:
 600                 return lttng_session_untrack_pid(session, (int) arg);
 601         case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
 602                 return lttng_session_list_tracker_pids(session);
 603         case LTTNG_KERNEL_SESSION_METADATA_REGEN:
 604                 return lttng_session_metadata_regenerate(session);
 605         case LTTNG_KERNEL_SESSION_STATEDUMP:
 606                 return lttng_session_statedump(session);
 607         case LTTNG_KERNEL_SESSION_SET_NAME:
 608         {
 609                 struct lttng_kernel_session_name name;
 610
 611                 if (copy_from_user(&name,
 612                                 (struct lttng_kernel_session_name __user *) arg,
 613                                 sizeof(struct lttng_kernel_session_name)))
 614                         return -EFAULT;
 615                 return lttng_abi_session_set_name(session, &name);
 616         }
 617         case LTTNG_KERNEL_SESSION_SET_CREATION_TIME:
 618         {
 619                 struct lttng_kernel_session_creation_time time;
 620
 621                 if (copy_from_user(&time,
 622                                 (struct lttng_kernel_session_creation_time __user *) arg,
 623                                 sizeof(struct lttng_kernel_session_creation_time)))
 624                         return -EFAULT;
 625                 return lttng_abi_session_set_creation_time(session, &time);
 626         }
 627         default:
 628                 return -ENOIOCTLCMD;
 629         }
 630 }
 631
 632 /*
 633  * Called when the last file reference is dropped.
 634  *
 635  * Big fat note: channels and events are invariant for the whole session after
 636  * their creation. So this session destruction also destroys all channel and
 637  * event structures specific to this session (they are not destroyed when their
 638  * individual file is released).
 639  */
 640 static
 641 int lttng_session_release(struct inode *inode, struct file *file)
 642 {
 643         struct lttng_session *session = file->private_data;
 644
 645         if (session)
 646                 lttng_session_destroy(session);
 647         return 0;
 648 }
 649
 650 static const struct file_operations lttng_session_fops = {
 651         .owner = THIS_MODULE,
 652         .release = lttng_session_release,
 653         .unlocked_ioctl = lttng_session_ioctl,
 654 #ifdef CONFIG_COMPAT
 655         .compat_ioctl = lttng_session_ioctl,
 656 #endif
 657 };
 658
 659 /**
 660  *      lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
 661  *      @filp: the file
 662  *      @wait: poll table
 663  *
 664  *      Handles the poll operations for the metadata channels.
 665  */
 666 static
 667 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 668                 poll_table *wait)
 669 {
 670         struct lttng_metadata_stream *stream = filp->private_data;
 671         struct lib_ring_buffer *buf = stream->priv;
 672         int finalized;
 673         unsigned int mask = 0;
 674
 675         if (filp->f_mode & FMODE_READ) {
 676                 poll_wait_set_exclusive(wait);
 677                 poll_wait(filp, &stream->read_wait, wait);
 678
 679                 finalized = stream->finalized;
 680
 681                 /*
 682                  * lib_ring_buffer_is_finalized() contains a smp_rmb()
 683                  * ordering finalized load before offsets loads.
 684                  */
 685                 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
 686
 687                 if (finalized)
 688                         mask |= POLLHUP;
 689
 690                 mutex_lock(&stream->metadata_cache->lock);
 691                 if (stream->metadata_cache->metadata_written >
 692                                 stream->metadata_out)
 693                         mask |= POLLIN;
 694                 mutex_unlock(&stream->metadata_cache->lock);
 695         }
 696
 697         return mask;
 698 }
 699
 700 static
 701 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 702                 unsigned int cmd, unsigned long arg)
 703 {
 704         struct lttng_metadata_stream *stream = filp->private_data;
 705
 706         stream->metadata_out = stream->metadata_in;
 707 }
 708
 709 /*
 710  * Reset the counter of how much metadata has been consumed to 0. That way,
 711  * the consumer receives the content of the metadata cache unchanged. This is
 712  * different from the metadata_regenerate where the offset from epoch is
 713  * resampled, here we want the exact same content as the last time the metadata
 714  * was generated. This command is only possible if all the metadata written
 715  * in the cache has been output to the metadata stream to avoid corrupting the
 716  * metadata file.
 717  *
 718  * Return 0 on success, a negative value on error.
 719  */
 720 static
 721 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
 722 {
 723         int ret;
 724         struct lttng_metadata_cache *cache = stream->metadata_cache;
 725
 726         mutex_lock(&cache->lock);
 727         if (stream->metadata_out != cache->metadata_written) {
 728                 ret = -EBUSY;
 729                 goto end;
 730         }
 731         stream->metadata_out = 0;
 732         stream->metadata_in = 0;
 733         wake_up_interruptible(&stream->read_wait);
 734         ret = 0;
 735
 736 end:
 737         mutex_unlock(&cache->lock);
 738         return ret;
 739 }
 740
 741 static
 742 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 743                 unsigned int cmd, unsigned long arg)
 744 {
 745         int ret;
 746         struct lttng_metadata_stream *stream = filp->private_data;
 747         struct lib_ring_buffer *buf = stream->priv;
 748         unsigned int rb_cmd;
 749         bool coherent;
 750
 751         if (cmd == RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
 752                 rb_cmd = RING_BUFFER_GET_NEXT_SUBBUF;
 753         else
 754                 rb_cmd = cmd;
 755
 756         switch (cmd) {
 757         case RING_BUFFER_GET_NEXT_SUBBUF:
 758         {
 759                 struct lttng_metadata_stream *stream = filp->private_data;
 760                 struct lib_ring_buffer *buf = stream->priv;
 761                 struct channel *chan = buf->backend.chan;
 762
 763                 ret = lttng_metadata_output_channel(stream, chan, NULL);
 764                 if (ret > 0) {
 765                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 766                         ret = 0;
 767                 } else if (ret < 0)
 768                         goto err;
 769                 break;
 770         }
 771         case RING_BUFFER_GET_SUBBUF:
 772         {
 773                 /*
 774                  * Random access is not allowed for metadata channel.
 775                  */
 776                 return -ENOSYS;
 777         }
 778         case RING_BUFFER_FLUSH_EMPTY:   /* Fall-through. */
 779         case RING_BUFFER_FLUSH:
 780         {
 781                 struct lttng_metadata_stream *stream = filp->private_data;
 782                 struct lib_ring_buffer *buf = stream->priv;
 783                 struct channel *chan = buf->backend.chan;
 784
 785                 /*
 786                  * Before doing the actual ring buffer flush, write up to one
 787                  * packet of metadata in the ring buffer.
 788                  */
 789                 ret = lttng_metadata_output_channel(stream, chan, NULL);
 790                 if (ret < 0)
 791                         goto err;
 792                 break;
 793         }
 794         case RING_BUFFER_GET_METADATA_VERSION:
 795         {
 796                 struct lttng_metadata_stream *stream = filp->private_data;
 797
 798                 return put_u64(stream->version, arg);
 799         }
 800         case RING_BUFFER_METADATA_CACHE_DUMP:
 801         {
 802                 struct lttng_metadata_stream *stream = filp->private_data;
 803
 804                 return lttng_metadata_cache_dump(stream);
 805         }
 806         case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
 807         {
 808                 struct lttng_metadata_stream *stream = filp->private_data;
 809                 struct lib_ring_buffer *buf = stream->priv;
 810                 struct channel *chan = buf->backend.chan;
 811
 812                 ret = lttng_metadata_output_channel(stream, chan, &coherent);
 813                 if (ret > 0) {
 814                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 815                         ret = 0;
 816                 } else if (ret < 0) {
 817                         goto err;
 818                 }
 819                 break;
 820         }
 821         default:
 822                 break;
 823         }
 824         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 825
 826         /* Performing lib ring buffer ioctl after our own. */
 827         ret = lib_ring_buffer_ioctl(filp, rb_cmd, arg, buf);
 828         if (ret < 0)
 829                 goto err;
 830
 831         switch (cmd) {
 832         case RING_BUFFER_PUT_NEXT_SUBBUF:
 833         {
 834                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 835                                 cmd, arg);
 836                 break;
 837         }
 838         case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
 839         {
 840                 return put_u32(coherent, arg);
 841         }
 842         default:
 843                 break;
 844         }
 845 err:
 846         return ret;
 847 }
 848
 849 #ifdef CONFIG_COMPAT
 850 static
 851 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 852                 unsigned int cmd, unsigned long arg)
 853 {
 854         int ret;
 855         struct lttng_metadata_stream *stream = filp->private_data;
 856         struct lib_ring_buffer *buf = stream->priv;
 857         unsigned int rb_cmd;
 858         bool coherent;
 859
 860         if (cmd == RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
 861                 rb_cmd = RING_BUFFER_GET_NEXT_SUBBUF;
 862         else
 863                 rb_cmd = cmd;
 864
 865         switch (cmd) {
 866         case RING_BUFFER_GET_NEXT_SUBBUF:
 867         {
 868                 struct lttng_metadata_stream *stream = filp->private_data;
 869                 struct lib_ring_buffer *buf = stream->priv;
 870                 struct channel *chan = buf->backend.chan;
 871
 872                 ret = lttng_metadata_output_channel(stream, chan, NULL);
 873                 if (ret > 0) {
 874                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 875                         ret = 0;
 876                 } else if (ret < 0)
 877                         goto err;
 878                 break;
 879         }
 880         case RING_BUFFER_GET_SUBBUF:
 881         {
 882                 /*
 883                  * Random access is not allowed for metadata channel.
 884                  */
 885                 return -ENOSYS;
 886         }
 887         case RING_BUFFER_FLUSH_EMPTY:   /* Fall-through. */
 888         case RING_BUFFER_FLUSH:
 889         {
 890                 struct lttng_metadata_stream *stream = filp->private_data;
 891                 struct lib_ring_buffer *buf = stream->priv;
 892                 struct channel *chan = buf->backend.chan;
 893
 894                 /*
 895                  * Before doing the actual ring buffer flush, write up to one
 896                  * packet of metadata in the ring buffer.
 897                  */
 898                 ret = lttng_metadata_output_channel(stream, chan, NULL);
 899                 if (ret < 0)
 900                         goto err;
 901                 break;
 902         }
 903         case RING_BUFFER_GET_METADATA_VERSION:
 904         {
 905                 struct lttng_metadata_stream *stream = filp->private_data;
 906
 907                 return put_u64(stream->version, arg);
 908         }
 909         case RING_BUFFER_METADATA_CACHE_DUMP:
 910         {
 911                 struct lttng_metadata_stream *stream = filp->private_data;
 912
 913                 return lttng_metadata_cache_dump(stream);
 914         }
 915         case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
 916         {
 917                 struct lttng_metadata_stream *stream = filp->private_data;
 918                 struct lib_ring_buffer *buf = stream->priv;
 919                 struct channel *chan = buf->backend.chan;
 920
 921                 ret = lttng_metadata_output_channel(stream, chan, &coherent);
 922                 if (ret > 0) {
 923                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 924                         ret = 0;
 925                 } else if (ret < 0) {
 926                         goto err;
 927                 }
 928                 break;
 929         }
 930         default:
 931                 break;
 932         }
 933         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 934
 935         /* Performing lib ring buffer ioctl after our own. */
 936         ret = lib_ring_buffer_compat_ioctl(filp, rb_cmd, arg, buf);
 937         if (ret < 0)
 938                 goto err;
 939
 940         switch (cmd) {
 941         case RING_BUFFER_PUT_NEXT_SUBBUF:
 942         {
 943                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 944                                 cmd, arg);
 945                 break;
 946         }
 947         case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
 948         {
 949                 return put_u32(coherent, arg);
 950         }
 951         default:
 952                 break;
 953         }
 954 err:
 955         return ret;
 956 }
 957 #endif
 958
 959 /*
 960  * This is not used by anonymous file descriptors. This code is left
 961  * there if we ever want to implement an inode with open() operation.
 962  */
 963 static
 964 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 965 {
 966         struct lttng_metadata_stream *stream = inode->i_private;
 967         struct lib_ring_buffer *buf = stream->priv;
 968
 969         file->private_data = buf;
 970         /*
 971          * Since life-time of metadata cache differs from that of
 972          * session, we need to keep our own reference on the transport.
 973          */
 974         if (!try_module_get(stream->transport->owner)) {
 975                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 976                 return -EBUSY;
 977         }
 978         return lib_ring_buffer_open(inode, file, buf);
 979 }
 980
 981 static
 982 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
 983 {
 984         struct lttng_metadata_stream *stream = file->private_data;
 985         struct lib_ring_buffer *buf = stream->priv;
 986
 987         mutex_lock(&stream->metadata_cache->lock);
 988         list_del(&stream->list);
 989         mutex_unlock(&stream->metadata_cache->lock);
 990         kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
 991         module_put(stream->transport->owner);
 992         kfree(stream);
 993         return lib_ring_buffer_release(inode, file, buf);
 994 }
 995
 996 static
 997 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 998                 struct pipe_inode_info *pipe, size_t len,
 999                 unsigned int flags)
1000 {
1001         struct lttng_metadata_stream *stream = in->private_data;
1002         struct lib_ring_buffer *buf = stream->priv;
1003
1004         return lib_ring_buffer_splice_read(in, ppos, pipe, len,
1005                         flags, buf);
1006 }
1007
1008 static
1009 int lttng_metadata_ring_buffer_mmap(struct file *filp,
1010                 struct vm_area_struct *vma)
1011 {
1012         struct lttng_metadata_stream *stream = filp->private_data;
1013         struct lib_ring_buffer *buf = stream->priv;
1014
1015         return lib_ring_buffer_mmap(filp, vma, buf);
1016 }
1017
1018 static
1019 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
1020         .owner = THIS_MODULE,
1021         .open = lttng_metadata_ring_buffer_open,
1022         .release = lttng_metadata_ring_buffer_release,
1023         .poll = lttng_metadata_ring_buffer_poll,
1024         .splice_read = lttng_metadata_ring_buffer_splice_read,
1025         .mmap = lttng_metadata_ring_buffer_mmap,
1026         .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
1027         .llseek = vfs_lib_ring_buffer_no_llseek,
1028 #ifdef CONFIG_COMPAT
1029         .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
1030 #endif
1031 };
1032
1033 static
1034 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1035                 const struct file_operations *fops)
1036 {
1037         int stream_fd, ret;
1038         struct file *stream_file;
1039
1040         stream_fd = lttng_get_unused_fd();
1041         if (stream_fd < 0) {
1042                 ret = stream_fd;
1043                 goto fd_error;
1044         }
1045         stream_file = anon_inode_getfile("[lttng_stream]", fops,
1046                         stream_priv, O_RDWR);
1047         if (IS_ERR(stream_file)) {
1048                 ret = PTR_ERR(stream_file);
1049                 goto file_error;
1050         }
1051         /*
1052          * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1053          * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1054          * file descriptor, so we set FMODE_PREAD here.
1055          */
1056         stream_file->f_mode |= FMODE_PREAD;
1057         fd_install(stream_fd, stream_file);
1058         /*
1059          * The stream holds a reference to the channel within the generic ring
1060          * buffer library, so no need to hold a refcount on the channel and
1061          * session files here.
1062          */
1063         return stream_fd;
1064
1065 file_error:
1066         put_unused_fd(stream_fd);
1067 fd_error:
1068         return ret;
1069 }
1070
1071 static
1072 int lttng_abi_open_stream(struct file *channel_file)
1073 {
1074         struct lttng_channel *channel = channel_file->private_data;
1075         struct lib_ring_buffer *buf;
1076         int ret;
1077         void *stream_priv;
1078
1079         buf = channel->ops->buffer_read_open(channel->chan);
1080         if (!buf)
1081                 return -ENOENT;
1082
1083         stream_priv = buf;
1084         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1085                         &lttng_stream_ring_buffer_file_operations);
1086         if (ret < 0)
1087                 goto fd_error;
1088
1089         return ret;
1090
1091 fd_error:
1092         channel->ops->buffer_read_close(buf);
1093         return ret;
1094 }
1095
1096 static
1097 int lttng_abi_open_metadata_stream(struct file *channel_file)
1098 {
1099         struct lttng_channel *channel = channel_file->private_data;
1100         struct lttng_session *session = channel->session;
1101         struct lib_ring_buffer *buf;
1102         int ret;
1103         struct lttng_metadata_stream *metadata_stream;
1104         void *stream_priv;
1105
1106         buf = channel->ops->buffer_read_open(channel->chan);
1107         if (!buf)
1108                 return -ENOENT;
1109
1110         metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1111                         GFP_KERNEL);
1112         if (!metadata_stream) {
1113                 ret = -ENOMEM;
1114                 goto nomem;
1115         }
1116         metadata_stream->metadata_cache = session->metadata_cache;
1117         init_waitqueue_head(&metadata_stream->read_wait);
1118         metadata_stream->priv = buf;
1119         stream_priv = metadata_stream;
1120         metadata_stream->transport = channel->transport;
1121         /* Initial state is an empty metadata, considered as incoherent. */
1122         metadata_stream->coherent = false;
1123
1124         /*
1125          * Since life-time of metadata cache differs from that of
1126          * session, we need to keep our own reference on the transport.
1127          */
1128         if (!try_module_get(metadata_stream->transport->owner)) {
1129                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1130                 ret = -EINVAL;
1131                 goto notransport;
1132         }
1133
1134         if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1135                 ret = -EOVERFLOW;
1136                 goto kref_error;
1137         }
1138
1139         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1140                         &lttng_metadata_ring_buffer_file_operations);
1141         if (ret < 0)
1142                 goto fd_error;
1143
1144         mutex_lock(&session->metadata_cache->lock);
1145         list_add(&metadata_stream->list,
1146                 &session->metadata_cache->metadata_stream);
1147         mutex_unlock(&session->metadata_cache->lock);
1148         return ret;
1149
1150 fd_error:
1151         kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1152 kref_error:
1153         module_put(metadata_stream->transport->owner);
1154 notransport:
1155         kfree(metadata_stream);
1156 nomem:
1157         channel->ops->buffer_read_close(buf);
1158         return ret;
1159 }
1160
1161 static
1162 int lttng_abi_create_event(struct file *channel_file,
1163                            struct lttng_kernel_event *event_param)
1164 {
1165         struct lttng_channel *channel = channel_file->private_data;
1166         int event_fd, ret;
1167         struct file *event_file;
1168         void *priv;
1169
1170         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1171         switch (event_param->instrumentation) {
1172         case LTTNG_KERNEL_KRETPROBE:
1173                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1174                 break;
1175         case LTTNG_KERNEL_KPROBE:
1176                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1177                 break;
1178         case LTTNG_KERNEL_FUNCTION:
1179                 WARN_ON_ONCE(1);
1180                 /* Not implemented. */
1181                 break;
1182         default:
1183                 break;
1184         }
1185         event_fd = lttng_get_unused_fd();
1186         if (event_fd < 0) {
1187                 ret = event_fd;
1188                 goto fd_error;
1189         }
1190         event_file = anon_inode_getfile("[lttng_event]",
1191                                         &lttng_event_fops,
1192                                         NULL, O_RDWR);
1193         if (IS_ERR(event_file)) {
1194                 ret = PTR_ERR(event_file);
1195                 goto file_error;
1196         }
1197         /* The event holds a reference on the channel */
1198         if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1199                 ret = -EOVERFLOW;
1200                 goto refcount_error;
1201         }
1202         if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1203                         || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1204                 struct lttng_enabler *enabler;
1205
1206                 if (strutils_is_star_glob_pattern(event_param->name)) {
1207                         /*
1208                          * If the event name is a star globbing pattern,
1209                          * we create the special star globbing enabler.
1210                          */
1211                         enabler = lttng_enabler_create(LTTNG_ENABLER_STAR_GLOB,
1212                                 event_param, channel);
1213                 } else {
1214                         enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
1215                                 event_param, channel);
1216                 }
1217                 priv = enabler;
1218         } else {
1219                 struct lttng_event *event;
1220
1221                 /*
1222                  * We tolerate no failure path after event creation. It
1223                  * will stay invariant for the rest of the session.
1224                  */
1225                 event = lttng_event_create(channel, event_param,
1226                                 NULL, NULL,
1227                                 event_param->instrumentation);
1228                 WARN_ON_ONCE(!event);
1229                 if (IS_ERR(event)) {
1230                         ret = PTR_ERR(event);
1231                         goto event_error;
1232                 }
1233                 priv = event;
1234         }
1235         event_file->private_data = priv;
1236         fd_install(event_fd, event_file);
1237         return event_fd;
1238
1239 event_error:
1240         atomic_long_dec(&channel_file->f_count);
1241 refcount_error:
1242         fput(event_file);
1243 file_error:
1244         put_unused_fd(event_fd);
1245 fd_error:
1246         return ret;
1247 }
1248
1249 /**
1250  *      lttng_channel_ioctl - lttng syscall through ioctl
1251  *
1252  *      @file: the file
1253  *      @cmd: the command
1254  *      @arg: command arg
1255  *
1256  *      This ioctl implements lttng commands:
1257  *      LTTNG_KERNEL_STREAM
1258  *              Returns an event stream file descriptor or failure.
1259  *              (typically, one event stream records events from one CPU)
1260  *      LTTNG_KERNEL_EVENT
1261  *              Returns an event file descriptor or failure.
1262  *      LTTNG_KERNEL_CONTEXT
1263  *              Prepend a context field to each event in the channel
1264  *      LTTNG_KERNEL_ENABLE
1265  *              Enable recording for events in this channel (weak enable)
1266  *      LTTNG_KERNEL_DISABLE
1267  *              Disable recording for events in this channel (strong disable)
1268  *
1269  * Channel and event file descriptors also hold a reference on the session.
1270  */
1271 static
1272 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1273 {
1274         struct lttng_channel *channel = file->private_data;
1275
1276         switch (cmd) {
1277         case LTTNG_KERNEL_OLD_STREAM:
1278         case LTTNG_KERNEL_STREAM:
1279                 return lttng_abi_open_stream(file);
1280         case LTTNG_KERNEL_OLD_EVENT:
1281         {
1282                 struct lttng_kernel_event *uevent_param;
1283                 struct lttng_kernel_old_event *old_uevent_param;
1284                 int ret;
1285
1286                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1287                                 GFP_KERNEL);
1288                 if (!uevent_param) {
1289                         ret = -ENOMEM;
1290                         goto old_event_end;
1291                 }
1292                 old_uevent_param = kmalloc(
1293                                 sizeof(struct lttng_kernel_old_event),
1294                                 GFP_KERNEL);
1295                 if (!old_uevent_param) {
1296                         ret = -ENOMEM;
1297                         goto old_event_error_free_param;
1298                 }
1299                 if (copy_from_user(old_uevent_param,
1300                                 (struct lttng_kernel_old_event __user *) arg,
1301                                 sizeof(struct lttng_kernel_old_event))) {
1302                         ret = -EFAULT;
1303                         goto old_event_error_free_old_param;
1304                 }
1305
1306                 memcpy(uevent_param->name, old_uevent_param->name,
1307                                 sizeof(uevent_param->name));
1308                 uevent_param->instrumentation =
1309                         old_uevent_param->instrumentation;
1310
1311                 switch (old_uevent_param->instrumentation) {
1312                 case LTTNG_KERNEL_KPROBE:
1313                         uevent_param->u.kprobe.addr =
1314                                 old_uevent_param->u.kprobe.addr;
1315                         uevent_param->u.kprobe.offset =
1316                                 old_uevent_param->u.kprobe.offset;
1317                         memcpy(uevent_param->u.kprobe.symbol_name,
1318                                 old_uevent_param->u.kprobe.symbol_name,
1319                                 sizeof(uevent_param->u.kprobe.symbol_name));
1320                         break;
1321                 case LTTNG_KERNEL_KRETPROBE:
1322                         uevent_param->u.kretprobe.addr =
1323                                 old_uevent_param->u.kretprobe.addr;
1324                         uevent_param->u.kretprobe.offset =
1325                                 old_uevent_param->u.kretprobe.offset;
1326                         memcpy(uevent_param->u.kretprobe.symbol_name,
1327                                 old_uevent_param->u.kretprobe.symbol_name,
1328                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1329                         break;
1330                 case LTTNG_KERNEL_FUNCTION:
1331                         WARN_ON_ONCE(1);
1332                         /* Not implemented. */
1333                         break;
1334                 default:
1335                         break;
1336                 }
1337                 ret = lttng_abi_create_event(file, uevent_param);
1338
1339 old_event_error_free_old_param:
1340                 kfree(old_uevent_param);
1341 old_event_error_free_param:
1342                 kfree(uevent_param);
1343 old_event_end:
1344                 return ret;
1345         }
1346         case LTTNG_KERNEL_EVENT:
1347         {
1348                 struct lttng_kernel_event uevent_param;
1349
1350                 if (copy_from_user(&uevent_param,
1351                                 (struct lttng_kernel_event __user *) arg,
1352                                 sizeof(uevent_param)))
1353                         return -EFAULT;
1354                 return lttng_abi_create_event(file, &uevent_param);
1355         }
1356         case LTTNG_KERNEL_OLD_CONTEXT:
1357         {
1358                 struct lttng_kernel_context *ucontext_param;
1359                 struct lttng_kernel_old_context *old_ucontext_param;
1360                 int ret;
1361
1362                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1363                                 GFP_KERNEL);
1364                 if (!ucontext_param) {
1365                         ret = -ENOMEM;
1366                         goto old_ctx_end;
1367                 }
1368                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1369                                 GFP_KERNEL);
1370                 if (!old_ucontext_param) {
1371                         ret = -ENOMEM;
1372                         goto old_ctx_error_free_param;
1373                 }
1374
1375                 if (copy_from_user(old_ucontext_param,
1376                                 (struct lttng_kernel_old_context __user *) arg,
1377                                 sizeof(struct lttng_kernel_old_context))) {
1378                         ret = -EFAULT;
1379                         goto old_ctx_error_free_old_param;
1380                 }
1381                 ucontext_param->ctx = old_ucontext_param->ctx;
1382                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1383                                 sizeof(ucontext_param->padding));
1384                 /* only type that uses the union */
1385                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1386                         ucontext_param->u.perf_counter.type =
1387                                 old_ucontext_param->u.perf_counter.type;
1388                         ucontext_param->u.perf_counter.config =
1389                                 old_ucontext_param->u.perf_counter.config;
1390                         memcpy(ucontext_param->u.perf_counter.name,
1391                                 old_ucontext_param->u.perf_counter.name,
1392                                 sizeof(ucontext_param->u.perf_counter.name));
1393                 }
1394
1395                 ret = lttng_abi_add_context(file,
1396                                 ucontext_param,
1397                                 &channel->ctx, channel->session);
1398
1399 old_ctx_error_free_old_param:
1400                 kfree(old_ucontext_param);
1401 old_ctx_error_free_param:
1402                 kfree(ucontext_param);
1403 old_ctx_end:
1404                 return ret;
1405         }
1406         case LTTNG_KERNEL_CONTEXT:
1407         {
1408                 struct lttng_kernel_context ucontext_param;
1409
1410                 if (copy_from_user(&ucontext_param,
1411                                 (struct lttng_kernel_context __user *) arg,
1412                                 sizeof(ucontext_param)))
1413                         return -EFAULT;
1414                 return lttng_abi_add_context(file,
1415                                 &ucontext_param,
1416                                 &channel->ctx, channel->session);
1417         }
1418         case LTTNG_KERNEL_OLD_ENABLE:
1419         case LTTNG_KERNEL_ENABLE:
1420                 return lttng_channel_enable(channel);
1421         case LTTNG_KERNEL_OLD_DISABLE:
1422         case LTTNG_KERNEL_DISABLE:
1423                 return lttng_channel_disable(channel);
1424         case LTTNG_KERNEL_SYSCALL_MASK:
1425                 return lttng_channel_syscall_mask(channel,
1426                         (struct lttng_kernel_syscall_mask __user *) arg);
1427         default:
1428                 return -ENOIOCTLCMD;
1429         }
1430 }
1431
1432 /**
1433  *      lttng_metadata_ioctl - lttng syscall through ioctl
1434  *
1435  *      @file: the file
1436  *      @cmd: the command
1437  *      @arg: command arg
1438  *
1439  *      This ioctl implements lttng commands:
1440  *      LTTNG_KERNEL_STREAM
1441  *              Returns an event stream file descriptor or failure.
1442  *
1443  * Channel and event file descriptors also hold a reference on the session.
1444  */
1445 static
1446 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1447 {
1448         switch (cmd) {
1449         case LTTNG_KERNEL_OLD_STREAM:
1450         case LTTNG_KERNEL_STREAM:
1451                 return lttng_abi_open_metadata_stream(file);
1452         default:
1453                 return -ENOIOCTLCMD;
1454         }
1455 }
1456
1457 /**
1458  *      lttng_channel_poll - lttng stream addition/removal monitoring
1459  *
1460  *      @file: the file
1461  *      @wait: poll table
1462  */
1463 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1464 {
1465         struct lttng_channel *channel = file->private_data;
1466         unsigned int mask = 0;
1467
1468         if (file->f_mode & FMODE_READ) {
1469                 poll_wait_set_exclusive(wait);
1470                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1471                           wait);
1472
1473                 if (channel->ops->is_disabled(channel->chan))
1474                         return POLLERR;
1475                 if (channel->ops->is_finalized(channel->chan))
1476                         return POLLHUP;
1477                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1478                         return POLLIN | POLLRDNORM;
1479                 return 0;
1480         }
1481         return mask;
1482
1483 }
1484
1485 static
1486 int lttng_channel_release(struct inode *inode, struct file *file)
1487 {
1488         struct lttng_channel *channel = file->private_data;
1489
1490         if (channel)
1491                 fput(channel->session->file);
1492         return 0;
1493 }
1494
1495 static
1496 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1497 {
1498         struct lttng_channel *channel = file->private_data;
1499
1500         if (channel) {
1501                 fput(channel->session->file);
1502                 lttng_metadata_channel_destroy(channel);
1503         }
1504
1505         return 0;
1506 }
1507
1508 static const struct file_operations lttng_channel_fops = {
1509         .owner = THIS_MODULE,
1510         .release = lttng_channel_release,
1511         .poll = lttng_channel_poll,
1512         .unlocked_ioctl = lttng_channel_ioctl,
1513 #ifdef CONFIG_COMPAT
1514         .compat_ioctl = lttng_channel_ioctl,
1515 #endif
1516 };
1517
1518 static const struct file_operations lttng_metadata_fops = {
1519         .owner = THIS_MODULE,
1520         .release = lttng_metadata_channel_release,
1521         .unlocked_ioctl = lttng_metadata_ioctl,
1522 #ifdef CONFIG_COMPAT
1523         .compat_ioctl = lttng_metadata_ioctl,
1524 #endif
1525 };
1526
1527 /**
1528  *      lttng_event_ioctl - lttng syscall through ioctl
1529  *
1530  *      @file: the file
1531  *      @cmd: the command
1532  *      @arg: command arg
1533  *
1534  *      This ioctl implements lttng commands:
1535  *      LTTNG_KERNEL_CONTEXT
1536  *              Prepend a context field to each record of this event
1537  *      LTTNG_KERNEL_ENABLE
1538  *              Enable recording for this event (weak enable)
1539  *      LTTNG_KERNEL_DISABLE
1540  *              Disable recording for this event (strong disable)
1541  */
1542 static
1543 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1544 {
1545         struct lttng_event *event;
1546         struct lttng_enabler *enabler;
1547         enum lttng_event_type *evtype = file->private_data;
1548
1549         switch (cmd) {
1550         case LTTNG_KERNEL_OLD_CONTEXT:
1551         {
1552                 /* Not implemented */
1553                 return -ENOSYS;
1554         }
1555         case LTTNG_KERNEL_CONTEXT:
1556         {
1557                 /* Not implemented */
1558                 return -ENOSYS;
1559         }
1560         case LTTNG_KERNEL_OLD_ENABLE:
1561         case LTTNG_KERNEL_ENABLE:
1562                 switch (*evtype) {
1563                 case LTTNG_TYPE_EVENT:
1564                         event = file->private_data;
1565                         return lttng_event_enable(event);
1566                 case LTTNG_TYPE_ENABLER:
1567                         enabler = file->private_data;
1568                         return lttng_enabler_enable(enabler);
1569                 default:
1570                         WARN_ON_ONCE(1);
1571                         return -ENOSYS;
1572                 }
1573         case LTTNG_KERNEL_OLD_DISABLE:
1574         case LTTNG_KERNEL_DISABLE:
1575                 switch (*evtype) {
1576                 case LTTNG_TYPE_EVENT:
1577                         event = file->private_data;
1578                         return lttng_event_disable(event);
1579                 case LTTNG_TYPE_ENABLER:
1580                         enabler = file->private_data;
1581                         return lttng_enabler_disable(enabler);
1582                 default:
1583                         WARN_ON_ONCE(1);
1584                         return -ENOSYS;
1585                 }
1586         case LTTNG_KERNEL_FILTER:
1587                 switch (*evtype) {
1588                 case LTTNG_TYPE_EVENT:
1589                         return -EINVAL;
1590                 case LTTNG_TYPE_ENABLER:
1591                 {
1592                         enabler = file->private_data;
1593                         return lttng_enabler_attach_bytecode(enabler,
1594                                 (struct lttng_kernel_filter_bytecode __user *) arg);
1595                 }
1596                 default:
1597                         WARN_ON_ONCE(1);
1598                         return -ENOSYS;
1599                 }
1600         case LTTNG_KERNEL_ADD_CALLSITE:
1601                 switch (*evtype) {
1602                 case LTTNG_TYPE_EVENT:
1603                         event = file->private_data;
1604                         return lttng_event_add_callsite(event,
1605                                 (struct lttng_kernel_event_callsite __user *) arg);
1606                 case LTTNG_TYPE_ENABLER:
1607                         return -EINVAL;
1608                 default:
1609                         WARN_ON_ONCE(1);
1610                         return -ENOSYS;
1611                 }
1612         default:
1613                 return -ENOIOCTLCMD;
1614         }
1615 }
1616
1617 static
1618 int lttng_event_release(struct inode *inode, struct file *file)
1619 {
1620         struct lttng_event *event;
1621         struct lttng_enabler *enabler;
1622         enum lttng_event_type *evtype = file->private_data;
1623
1624         if (!evtype)
1625                 return 0;
1626
1627         switch (*evtype) {
1628         case LTTNG_TYPE_EVENT:
1629                 event = file->private_data;
1630                 if (event)
1631                         fput(event->chan->file);
1632                 break;
1633         case LTTNG_TYPE_ENABLER:
1634                 enabler = file->private_data;
1635                 if (enabler)
1636                         fput(enabler->chan->file);
1637                 break;
1638         default:
1639                 WARN_ON_ONCE(1);
1640                 break;
1641         }
1642
1643         return 0;
1644 }
1645
1646 /* TODO: filter control ioctl */
1647 static const struct file_operations lttng_event_fops = {
1648         .owner = THIS_MODULE,
1649         .release = lttng_event_release,
1650         .unlocked_ioctl = lttng_event_ioctl,
1651 #ifdef CONFIG_COMPAT
1652         .compat_ioctl = lttng_event_ioctl,
1653 #endif
1654 };
1655
1656 static int put_u64(uint64_t val, unsigned long arg)
1657 {
1658         return put_user(val, (uint64_t __user *) arg);
1659 }
1660
1661 static int put_u32(uint32_t val, unsigned long arg)
1662 {
1663         return put_user(val, (uint32_t __user *) arg);
1664 }
1665
1666 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1667                 unsigned int cmd, unsigned long arg)
1668 {
1669         struct lib_ring_buffer *buf = filp->private_data;
1670         struct channel *chan = buf->backend.chan;
1671         const struct lib_ring_buffer_config *config = &chan->backend.config;
1672         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1673         int ret;
1674
1675         if (atomic_read(&chan->record_disabled))
1676                 return -EIO;
1677
1678         switch (cmd) {
1679         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1680         {
1681                 uint64_t ts;
1682
1683                 ret = ops->timestamp_begin(config, buf, &ts);
1684                 if (ret < 0)
1685                         goto error;
1686                 return put_u64(ts, arg);
1687         }
1688         case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1689         {
1690                 uint64_t ts;
1691
1692                 ret = ops->timestamp_end(config, buf, &ts);
1693                 if (ret < 0)
1694                         goto error;
1695                 return put_u64(ts, arg);
1696         }
1697         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1698         {
1699                 uint64_t ed;
1700
1701                 ret = ops->events_discarded(config, buf, &ed);
1702                 if (ret < 0)
1703                         goto error;
1704                 return put_u64(ed, arg);
1705         }
1706         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1707         {
1708                 uint64_t cs;
1709
1710                 ret = ops->content_size(config, buf, &cs);
1711                 if (ret < 0)
1712                         goto error;
1713                 return put_u64(cs, arg);
1714         }
1715         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1716         {
1717                 uint64_t ps;
1718
1719                 ret = ops->packet_size(config, buf, &ps);
1720                 if (ret < 0)
1721                         goto error;
1722                 return put_u64(ps, arg);
1723         }
1724         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1725         {
1726                 uint64_t si;
1727
1728                 ret = ops->stream_id(config, buf, &si);
1729                 if (ret < 0)
1730                         goto error;
1731                 return put_u64(si, arg);
1732         }
1733         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1734         {
1735                 uint64_t ts;
1736
1737                 ret = ops->current_timestamp(config, buf, &ts);
1738                 if (ret < 0)
1739                         goto error;
1740                 return put_u64(ts, arg);
1741         }
1742         case LTTNG_RING_BUFFER_GET_SEQ_NUM:
1743         {
1744                 uint64_t seq;
1745
1746                 ret = ops->sequence_number(config, buf, &seq);
1747                 if (ret < 0)
1748                         goto error;
1749                 return put_u64(seq, arg);
1750         }
1751         case LTTNG_RING_BUFFER_INSTANCE_ID:
1752         {
1753                 uint64_t id;
1754
1755                 ret = ops->instance_id(config, buf, &id);
1756                 if (ret < 0)
1757                         goto error;
1758                 return put_u64(id, arg);
1759         }
1760         default:
1761                 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1762                                 cmd, arg);
1763         }
1764
1765 error:
1766         return -ENOSYS;
1767 }
1768
1769 #ifdef CONFIG_COMPAT
1770 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1771                 unsigned int cmd, unsigned long arg)
1772 {
1773         struct lib_ring_buffer *buf = filp->private_data;
1774         struct channel *chan = buf->backend.chan;
1775         const struct lib_ring_buffer_config *config = &chan->backend.config;
1776         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1777         int ret;
1778
1779         if (atomic_read(&chan->record_disabled))
1780                 return -EIO;
1781
1782         switch (cmd) {
1783         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1784         {
1785                 uint64_t ts;
1786
1787                 ret = ops->timestamp_begin(config, buf, &ts);
1788                 if (ret < 0)
1789                         goto error;
1790                 return put_u64(ts, arg);
1791         }
1792         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1793         {
1794                 uint64_t ts;
1795
1796                 ret = ops->timestamp_end(config, buf, &ts);
1797                 if (ret < 0)
1798                         goto error;
1799                 return put_u64(ts, arg);
1800         }
1801         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1802         {
1803                 uint64_t ed;
1804
1805                 ret = ops->events_discarded(config, buf, &ed);
1806                 if (ret < 0)
1807                         goto error;
1808                 return put_u64(ed, arg);
1809         }
1810         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1811         {
1812                 uint64_t cs;
1813
1814                 ret = ops->content_size(config, buf, &cs);
1815                 if (ret < 0)
1816                         goto error;
1817                 return put_u64(cs, arg);
1818         }
1819         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1820         {
1821                 uint64_t ps;
1822
1823                 ret = ops->packet_size(config, buf, &ps);
1824                 if (ret < 0)
1825                         goto error;
1826                 return put_u64(ps, arg);
1827         }
1828         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1829         {
1830                 uint64_t si;
1831
1832                 ret = ops->stream_id(config, buf, &si);
1833                 if (ret < 0)
1834                         goto error;
1835                 return put_u64(si, arg);
1836         }
1837         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1838         {
1839                 uint64_t ts;
1840
1841                 ret = ops->current_timestamp(config, buf, &ts);
1842                 if (ret < 0)
1843                         goto error;
1844                 return put_u64(ts, arg);
1845         }
1846         case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
1847         {
1848                 uint64_t seq;
1849
1850                 ret = ops->sequence_number(config, buf, &seq);
1851                 if (ret < 0)
1852                         goto error;
1853                 return put_u64(seq, arg);
1854         }
1855         case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
1856         {
1857                 uint64_t id;
1858
1859                 ret = ops->instance_id(config, buf, &id);
1860                 if (ret < 0)
1861                         goto error;
1862                 return put_u64(id, arg);
1863         }
1864         default:
1865                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1866                                 cmd, arg);
1867         }
1868
1869 error:
1870         return -ENOSYS;
1871 }
1872 #endif /* CONFIG_COMPAT */
1873
1874 static void lttng_stream_override_ring_buffer_fops(void)
1875 {
1876         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1877         lttng_stream_ring_buffer_file_operations.open =
1878                 lib_ring_buffer_file_operations.open;
1879         lttng_stream_ring_buffer_file_operations.release =
1880                 lib_ring_buffer_file_operations.release;
1881         lttng_stream_ring_buffer_file_operations.poll =
1882                 lib_ring_buffer_file_operations.poll;
1883         lttng_stream_ring_buffer_file_operations.splice_read =
1884                 lib_ring_buffer_file_operations.splice_read;
1885         lttng_stream_ring_buffer_file_operations.mmap =
1886                 lib_ring_buffer_file_operations.mmap;
1887         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1888                 lttng_stream_ring_buffer_ioctl;
1889         lttng_stream_ring_buffer_file_operations.llseek =
1890                 lib_ring_buffer_file_operations.llseek;
1891 #ifdef CONFIG_COMPAT
1892         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1893                 lttng_stream_ring_buffer_compat_ioctl;
1894 #endif
1895 }
1896
1897 int __init lttng_abi_init(void)
1898 {
1899         int ret = 0;
1900
1901         wrapper_vmalloc_sync_mappings();
1902         lttng_clock_ref();
1903
1904         ret = lttng_tp_mempool_init();
1905         if (ret) {
1906                 goto error;
1907         }
1908
1909         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1910                                         &lttng_proc_ops, NULL);
1911
1912         if (!lttng_proc_dentry) {
1913                 printk(KERN_ERR "Error creating LTTng control file\n");
1914                 ret = -ENOMEM;
1915                 goto error;
1916         }
1917         lttng_stream_override_ring_buffer_fops();
1918         return 0;
1919
1920 error:
1921         lttng_tp_mempool_destroy();
1922         lttng_clock_unref();
1923         return ret;
1924 }
1925
1926 /* No __exit annotation because used by init error path too. */
1927 void lttng_abi_exit(void)
1928 {
1929         lttng_tp_mempool_destroy();
1930         lttng_clock_unref();
1931         if (lttng_proc_dentry)
1932                 remove_proc_entry("lttng", NULL);
1933 }