lttng-abi.c

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