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