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