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