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