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         struct lttng_kernel_channel chan_param;
 518         struct lttng_kernel_old_channel old_chan_param;
 519
 520         switch (cmd) {
 521         case LTTNG_KERNEL_OLD_CHANNEL:
 522         {
 523                 if (copy_from_user(&old_chan_param,
 524                                 (struct lttng_kernel_old_channel __user *) arg,
 525                                 sizeof(struct lttng_kernel_old_channel)))
 526                         return -EFAULT;
 527                 chan_param.overwrite = old_chan_param.overwrite;
 528                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 529                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 530                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 531                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 532                 chan_param.output = old_chan_param.output;
 533
 534                 return lttng_abi_create_channel(file, &chan_param,
 535                                 PER_CPU_CHANNEL);
 536         }
 537         case LTTNG_KERNEL_CHANNEL:
 538         {
 539                 if (copy_from_user(&chan_param,
 540                                 (struct lttng_kernel_channel __user *) arg,
 541                                 sizeof(struct lttng_kernel_channel)))
 542                         return -EFAULT;
 543                 return lttng_abi_create_channel(file, &chan_param,
 544                                 PER_CPU_CHANNEL);
 545         }
 546         case LTTNG_KERNEL_OLD_SESSION_START:
 547         case LTTNG_KERNEL_OLD_ENABLE:
 548         case LTTNG_KERNEL_SESSION_START:
 549         case LTTNG_KERNEL_ENABLE:
 550                 return lttng_session_enable(session);
 551         case LTTNG_KERNEL_OLD_SESSION_STOP:
 552         case LTTNG_KERNEL_OLD_DISABLE:
 553         case LTTNG_KERNEL_SESSION_STOP:
 554         case LTTNG_KERNEL_DISABLE:
 555                 return lttng_session_disable(session);
 556         case LTTNG_KERNEL_OLD_METADATA:
 557         {
 558                 if (copy_from_user(&old_chan_param,
 559                                 (struct lttng_kernel_old_channel __user *) arg,
 560                                 sizeof(struct lttng_kernel_old_channel)))
 561                         return -EFAULT;
 562                 chan_param.overwrite = old_chan_param.overwrite;
 563                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 564                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 565                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 566                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 567                 chan_param.output = old_chan_param.output;
 568
 569                 return lttng_abi_create_channel(file, &chan_param,
 570                                 METADATA_CHANNEL);
 571         }
 572         case LTTNG_KERNEL_METADATA:
 573         {
 574                 if (copy_from_user(&chan_param,
 575                                         (struct lttng_kernel_channel __user *) arg,
 576                                         sizeof(struct lttng_kernel_channel)))
 577                         return -EFAULT;
 578                 return lttng_abi_create_channel(file, &chan_param,
 579                                 METADATA_CHANNEL);
 580         }
 581         case LTTNG_KERNEL_SESSION_TRACK_PID:
 582                 return lttng_session_track_pid(session, (int) arg);
 583         case LTTNG_KERNEL_SESSION_UNTRACK_PID:
 584                 return lttng_session_untrack_pid(session, (int) arg);
 585         case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
 586                 return lttng_session_list_tracker_pids(session);
 587         case LTTNG_KERNEL_SESSION_METADATA_REGEN:
 588                 return lttng_session_metadata_regenerate(session);
 589         case LTTNG_KERNEL_SESSION_STATEDUMP:
 590                 return lttng_session_statedump(session);
 591         case LTTNG_KERNEL_SESSION_SET_NAME:
 592         {
 593                 struct lttng_kernel_session_name name;
 594
 595                 if (copy_from_user(&name,
 596                                 (struct lttng_kernel_session_name __user *) arg,
 597                                 sizeof(struct lttng_kernel_session_name)))
 598                         return -EFAULT;
 599                 return lttng_abi_session_set_name(session, &name);
 600         }
 601         case LTTNG_KERNEL_SESSION_SET_CREATION_TIME:
 602         {
 603                 struct lttng_kernel_session_creation_time time;
 604
 605                 if (copy_from_user(&time,
 606                                 (struct lttng_kernel_session_creation_time __user *) arg,
 607                                 sizeof(struct lttng_kernel_session_creation_time)))
 608                         return -EFAULT;
 609                 return lttng_abi_session_set_creation_time(session, &time);
 610         }
 611         default:
 612                 return -ENOIOCTLCMD;
 613         }
 614 }
 615
 616 /*
 617  * Called when the last file reference is dropped.
 618  *
 619  * Big fat note: channels and events are invariant for the whole session after
 620  * their creation. So this session destruction also destroys all channel and
 621  * event structures specific to this session (they are not destroyed when their
 622  * individual file is released).
 623  */
 624 static
 625 int lttng_session_release(struct inode *inode, struct file *file)
 626 {
 627         struct lttng_session *session = file->private_data;
 628
 629         if (session)
 630                 lttng_session_destroy(session);
 631         return 0;
 632 }
 633
 634 static const struct file_operations lttng_session_fops = {
 635         .owner = THIS_MODULE,
 636         .release = lttng_session_release,
 637         .unlocked_ioctl = lttng_session_ioctl,
 638 #ifdef CONFIG_COMPAT
 639         .compat_ioctl = lttng_session_ioctl,
 640 #endif
 641 };
 642
 643 /**
 644  *      lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
 645  *      @filp: the file
 646  *      @wait: poll table
 647  *
 648  *      Handles the poll operations for the metadata channels.
 649  */
 650 static
 651 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 652                 poll_table *wait)
 653 {
 654         struct lttng_metadata_stream *stream = filp->private_data;
 655         struct lib_ring_buffer *buf = stream->priv;
 656         int finalized;
 657         unsigned int mask = 0;
 658
 659         if (filp->f_mode & FMODE_READ) {
 660                 poll_wait_set_exclusive(wait);
 661                 poll_wait(filp, &stream->read_wait, wait);
 662
 663                 finalized = stream->finalized;
 664
 665                 /*
 666                  * lib_ring_buffer_is_finalized() contains a smp_rmb()
 667                  * ordering finalized load before offsets loads.
 668                  */
 669                 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
 670
 671                 if (finalized)
 672                         mask |= POLLHUP;
 673
 674                 mutex_lock(&stream->metadata_cache->lock);
 675                 if (stream->metadata_cache->metadata_written >
 676                                 stream->metadata_out)
 677                         mask |= POLLIN;
 678                 mutex_unlock(&stream->metadata_cache->lock);
 679         }
 680
 681         return mask;
 682 }
 683
 684 static
 685 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 686                 unsigned int cmd, unsigned long arg)
 687 {
 688         struct lttng_metadata_stream *stream = filp->private_data;
 689
 690         stream->metadata_out = stream->metadata_in;
 691 }
 692
 693 /*
 694  * Reset the counter of how much metadata has been consumed to 0. That way,
 695  * the consumer receives the content of the metadata cache unchanged. This is
 696  * different from the metadata_regenerate where the offset from epoch is
 697  * resampled, here we want the exact same content as the last time the metadata
 698  * was generated. This command is only possible if all the metadata written
 699  * in the cache has been output to the metadata stream to avoid corrupting the
 700  * metadata file.
 701  *
 702  * Return 0 on success, a negative value on error.
 703  */
 704 static
 705 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
 706 {
 707         int ret;
 708         struct lttng_metadata_cache *cache = stream->metadata_cache;
 709
 710         mutex_lock(&cache->lock);
 711         if (stream->metadata_out != cache->metadata_written) {
 712                 ret = -EBUSY;
 713                 goto end;
 714         }
 715         stream->metadata_out = 0;
 716         stream->metadata_in = 0;
 717         wake_up_interruptible(&stream->read_wait);
 718         ret = 0;
 719
 720 end:
 721         mutex_unlock(&cache->lock);
 722         return ret;
 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         case RING_BUFFER_METADATA_CACHE_DUMP:
 778         {
 779                 struct lttng_metadata_stream *stream = filp->private_data;
 780
 781                 return lttng_metadata_cache_dump(stream);
 782         }
 783         default:
 784                 break;
 785         }
 786         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 787
 788         /* Performing lib ring buffer ioctl after our own. */
 789         ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
 790         if (ret < 0)
 791                 goto err;
 792
 793         switch (cmd) {
 794         case RING_BUFFER_PUT_NEXT_SUBBUF:
 795         {
 796                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 797                                 cmd, arg);
 798                 break;
 799         }
 800         default:
 801                 break;
 802         }
 803 err:
 804         return ret;
 805 }
 806
 807 #ifdef CONFIG_COMPAT
 808 static
 809 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 810                 unsigned int cmd, unsigned long arg)
 811 {
 812         int ret;
 813         struct lttng_metadata_stream *stream = filp->private_data;
 814         struct lib_ring_buffer *buf = stream->priv;
 815
 816         switch (cmd) {
 817         case RING_BUFFER_GET_NEXT_SUBBUF:
 818         {
 819                 struct lttng_metadata_stream *stream = filp->private_data;
 820                 struct lib_ring_buffer *buf = stream->priv;
 821                 struct channel *chan = buf->backend.chan;
 822
 823                 ret = lttng_metadata_output_channel(stream, chan);
 824                 if (ret > 0) {
 825                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 826                         ret = 0;
 827                 } else if (ret < 0)
 828                         goto err;
 829                 break;
 830         }
 831         case RING_BUFFER_GET_SUBBUF:
 832         {
 833                 /*
 834                  * Random access is not allowed for metadata channel.
 835                  */
 836                 return -ENOSYS;
 837         }
 838         case RING_BUFFER_FLUSH_EMPTY:   /* Fall-through. */
 839         case RING_BUFFER_FLUSH:
 840         {
 841                 struct lttng_metadata_stream *stream = filp->private_data;
 842                 struct lib_ring_buffer *buf = stream->priv;
 843                 struct channel *chan = buf->backend.chan;
 844
 845                 /*
 846                  * Before doing the actual ring buffer flush, write up to one
 847                  * packet of metadata in the ring buffer.
 848                  */
 849                 ret = lttng_metadata_output_channel(stream, chan);
 850                 if (ret < 0)
 851                         goto err;
 852                 break;
 853         }
 854         case RING_BUFFER_GET_METADATA_VERSION:
 855         {
 856                 struct lttng_metadata_stream *stream = filp->private_data;
 857
 858                 return put_u64(stream->version, arg);
 859         }
 860         case RING_BUFFER_METADATA_CACHE_DUMP:
 861         {
 862                 struct lttng_metadata_stream *stream = filp->private_data;
 863
 864                 return lttng_metadata_cache_dump(stream);
 865         }
 866         default:
 867                 break;
 868         }
 869         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 870
 871         /* Performing lib ring buffer ioctl after our own. */
 872         ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
 873         if (ret < 0)
 874                 goto err;
 875
 876         switch (cmd) {
 877         case RING_BUFFER_PUT_NEXT_SUBBUF:
 878         {
 879                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 880                                 cmd, arg);
 881                 break;
 882         }
 883         default:
 884                 break;
 885         }
 886 err:
 887         return ret;
 888 }
 889 #endif
 890
 891 /*
 892  * This is not used by anonymous file descriptors. This code is left
 893  * there if we ever want to implement an inode with open() operation.
 894  */
 895 static
 896 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 897 {
 898         struct lttng_metadata_stream *stream = inode->i_private;
 899         struct lib_ring_buffer *buf = stream->priv;
 900
 901         file->private_data = buf;
 902         /*
 903          * Since life-time of metadata cache differs from that of
 904          * session, we need to keep our own reference on the transport.
 905          */
 906         if (!try_module_get(stream->transport->owner)) {
 907                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 908                 return -EBUSY;
 909         }
 910         return lib_ring_buffer_open(inode, file, buf);
 911 }
 912
 913 static
 914 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
 915 {
 916         struct lttng_metadata_stream *stream = file->private_data;
 917         struct lib_ring_buffer *buf = stream->priv;
 918
 919         kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
 920         module_put(stream->transport->owner);
 921         return lib_ring_buffer_release(inode, file, buf);
 922 }
 923
 924 static
 925 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 926                 struct pipe_inode_info *pipe, size_t len,
 927                 unsigned int flags)
 928 {
 929         struct lttng_metadata_stream *stream = in->private_data;
 930         struct lib_ring_buffer *buf = stream->priv;
 931
 932         return lib_ring_buffer_splice_read(in, ppos, pipe, len,
 933                         flags, buf);
 934 }
 935
 936 static
 937 int lttng_metadata_ring_buffer_mmap(struct file *filp,
 938                 struct vm_area_struct *vma)
 939 {
 940         struct lttng_metadata_stream *stream = filp->private_data;
 941         struct lib_ring_buffer *buf = stream->priv;
 942
 943         return lib_ring_buffer_mmap(filp, vma, buf);
 944 }
 945
 946 static
 947 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
 948         .owner = THIS_MODULE,
 949         .open = lttng_metadata_ring_buffer_open,
 950         .release = lttng_metadata_ring_buffer_release,
 951         .poll = lttng_metadata_ring_buffer_poll,
 952         .splice_read = lttng_metadata_ring_buffer_splice_read,
 953         .mmap = lttng_metadata_ring_buffer_mmap,
 954         .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
 955         .llseek = vfs_lib_ring_buffer_no_llseek,
 956 #ifdef CONFIG_COMPAT
 957         .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
 958 #endif
 959 };
 960
 961 static
 962 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
 963                 const struct file_operations *fops)
 964 {
 965         int stream_fd, ret;
 966         struct file *stream_file;
 967
 968         stream_fd = lttng_get_unused_fd();
 969         if (stream_fd < 0) {
 970                 ret = stream_fd;
 971                 goto fd_error;
 972         }
 973         stream_file = anon_inode_getfile("[lttng_stream]", fops,
 974                         stream_priv, O_RDWR);
 975         if (IS_ERR(stream_file)) {
 976                 ret = PTR_ERR(stream_file);
 977                 goto file_error;
 978         }
 979         /*
 980          * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
 981          * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
 982          * file descriptor, so we set FMODE_PREAD here.
 983          */
 984         stream_file->f_mode |= FMODE_PREAD;
 985         fd_install(stream_fd, stream_file);
 986         /*
 987          * The stream holds a reference to the channel within the generic ring
 988          * buffer library, so no need to hold a refcount on the channel and
 989          * session files here.
 990          */
 991         return stream_fd;
 992
 993 file_error:
 994         put_unused_fd(stream_fd);
 995 fd_error:
 996         return ret;
 997 }
 998
 999 static
1000 int lttng_abi_open_stream(struct file *channel_file)
1001 {
1002         struct lttng_channel *channel = channel_file->private_data;
1003         struct lib_ring_buffer *buf;
1004         int ret;
1005         void *stream_priv;
1006
1007         buf = channel->ops->buffer_read_open(channel->chan);
1008         if (!buf)
1009                 return -ENOENT;
1010
1011         stream_priv = buf;
1012         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1013                         &lttng_stream_ring_buffer_file_operations);
1014         if (ret < 0)
1015                 goto fd_error;
1016
1017         return ret;
1018
1019 fd_error:
1020         channel->ops->buffer_read_close(buf);
1021         return ret;
1022 }
1023
1024 static
1025 int lttng_abi_open_metadata_stream(struct file *channel_file)
1026 {
1027         struct lttng_channel *channel = channel_file->private_data;
1028         struct lttng_session *session = channel->session;
1029         struct lib_ring_buffer *buf;
1030         int ret;
1031         struct lttng_metadata_stream *metadata_stream;
1032         void *stream_priv;
1033
1034         buf = channel->ops->buffer_read_open(channel->chan);
1035         if (!buf)
1036                 return -ENOENT;
1037
1038         metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1039                         GFP_KERNEL);
1040         if (!metadata_stream) {
1041                 ret = -ENOMEM;
1042                 goto nomem;
1043         }
1044         metadata_stream->metadata_cache = session->metadata_cache;
1045         init_waitqueue_head(&metadata_stream->read_wait);
1046         metadata_stream->priv = buf;
1047         stream_priv = metadata_stream;
1048         metadata_stream->transport = channel->transport;
1049
1050         /*
1051          * Since life-time of metadata cache differs from that of
1052          * session, we need to keep our own reference on the transport.
1053          */
1054         if (!try_module_get(metadata_stream->transport->owner)) {
1055                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1056                 ret = -EINVAL;
1057                 goto notransport;
1058         }
1059
1060         if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1061                 ret = -EOVERFLOW;
1062                 goto kref_error;
1063         }
1064
1065         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1066                         &lttng_metadata_ring_buffer_file_operations);
1067         if (ret < 0)
1068                 goto fd_error;
1069
1070         list_add(&metadata_stream->list,
1071                 &session->metadata_cache->metadata_stream);
1072         return ret;
1073
1074 fd_error:
1075         kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1076 kref_error:
1077         module_put(metadata_stream->transport->owner);
1078 notransport:
1079         kfree(metadata_stream);
1080 nomem:
1081         channel->ops->buffer_read_close(buf);
1082         return ret;
1083 }
1084
1085 static
1086 int lttng_abi_create_event(struct file *channel_file,
1087                            struct lttng_kernel_event *event_param)
1088 {
1089         struct lttng_channel *channel = channel_file->private_data;
1090         int event_fd, ret;
1091         struct file *event_file;
1092         void *priv;
1093
1094         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1095         switch (event_param->instrumentation) {
1096         case LTTNG_KERNEL_KRETPROBE:
1097                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1098                 break;
1099         case LTTNG_KERNEL_KPROBE:
1100                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1101                 break;
1102         case LTTNG_KERNEL_FUNCTION:
1103                 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1104                 break;
1105         default:
1106                 break;
1107         }
1108         event_fd = lttng_get_unused_fd();
1109         if (event_fd < 0) {
1110                 ret = event_fd;
1111                 goto fd_error;
1112         }
1113         event_file = anon_inode_getfile("[lttng_event]",
1114                                         &lttng_event_fops,
1115                                         NULL, O_RDWR);
1116         if (IS_ERR(event_file)) {
1117                 ret = PTR_ERR(event_file);
1118                 goto file_error;
1119         }
1120         /* The event holds a reference on the channel */
1121         if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1122                 ret = -EOVERFLOW;
1123                 goto refcount_error;
1124         }
1125         if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1126                         || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1127                 struct lttng_enabler *enabler;
1128
1129                 if (strutils_is_star_glob_pattern(event_param->name)) {
1130                         /*
1131                          * If the event name is a star globbing pattern,
1132                          * we create the special star globbing enabler.
1133                          */
1134                         enabler = lttng_enabler_create(LTTNG_ENABLER_STAR_GLOB,
1135                                 event_param, channel);
1136                 } else {
1137                         enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
1138                                 event_param, channel);
1139                 }
1140                 priv = enabler;
1141         } else {
1142                 struct lttng_event *event;
1143
1144                 /*
1145                  * We tolerate no failure path after event creation. It
1146                  * will stay invariant for the rest of the session.
1147                  */
1148                 event = lttng_event_create(channel, event_param,
1149                                 NULL, NULL,
1150                                 event_param->instrumentation);
1151                 WARN_ON_ONCE(!event);
1152                 if (IS_ERR(event)) {
1153                         ret = PTR_ERR(event);
1154                         goto event_error;
1155                 }
1156                 priv = event;
1157         }
1158         event_file->private_data = priv;
1159         fd_install(event_fd, event_file);
1160         return event_fd;
1161
1162 event_error:
1163         atomic_long_dec(&channel_file->f_count);
1164 refcount_error:
1165         fput(event_file);
1166 file_error:
1167         put_unused_fd(event_fd);
1168 fd_error:
1169         return ret;
1170 }
1171
1172 /**
1173  *      lttng_channel_ioctl - lttng syscall through ioctl
1174  *
1175  *      @file: the file
1176  *      @cmd: the command
1177  *      @arg: command arg
1178  *
1179  *      This ioctl implements lttng commands:
1180  *      LTTNG_KERNEL_STREAM
1181  *              Returns an event stream file descriptor or failure.
1182  *              (typically, one event stream records events from one CPU)
1183  *      LTTNG_KERNEL_EVENT
1184  *              Returns an event file descriptor or failure.
1185  *      LTTNG_KERNEL_CONTEXT
1186  *              Prepend a context field to each event in the channel
1187  *      LTTNG_KERNEL_ENABLE
1188  *              Enable recording for events in this channel (weak enable)
1189  *      LTTNG_KERNEL_DISABLE
1190  *              Disable recording for events in this channel (strong disable)
1191  *
1192  * Channel and event file descriptors also hold a reference on the session.
1193  */
1194 static
1195 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1196 {
1197         struct lttng_channel *channel = file->private_data;
1198
1199         switch (cmd) {
1200         case LTTNG_KERNEL_OLD_STREAM:
1201         case LTTNG_KERNEL_STREAM:
1202                 return lttng_abi_open_stream(file);
1203         case LTTNG_KERNEL_OLD_EVENT:
1204         {
1205                 struct lttng_kernel_event *uevent_param;
1206                 struct lttng_kernel_old_event *old_uevent_param;
1207                 int ret;
1208
1209                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1210                                 GFP_KERNEL);
1211                 if (!uevent_param) {
1212                         ret = -ENOMEM;
1213                         goto old_event_end;
1214                 }
1215                 old_uevent_param = kmalloc(
1216                                 sizeof(struct lttng_kernel_old_event),
1217                                 GFP_KERNEL);
1218                 if (!old_uevent_param) {
1219                         ret = -ENOMEM;
1220                         goto old_event_error_free_param;
1221                 }
1222                 if (copy_from_user(old_uevent_param,
1223                                 (struct lttng_kernel_old_event __user *) arg,
1224                                 sizeof(struct lttng_kernel_old_event))) {
1225                         ret = -EFAULT;
1226                         goto old_event_error_free_old_param;
1227                 }
1228
1229                 memcpy(uevent_param->name, old_uevent_param->name,
1230                                 sizeof(uevent_param->name));
1231                 uevent_param->instrumentation =
1232                         old_uevent_param->instrumentation;
1233
1234                 switch (old_uevent_param->instrumentation) {
1235                 case LTTNG_KERNEL_KPROBE:
1236                         uevent_param->u.kprobe.addr =
1237                                 old_uevent_param->u.kprobe.addr;
1238                         uevent_param->u.kprobe.offset =
1239                                 old_uevent_param->u.kprobe.offset;
1240                         memcpy(uevent_param->u.kprobe.symbol_name,
1241                                 old_uevent_param->u.kprobe.symbol_name,
1242                                 sizeof(uevent_param->u.kprobe.symbol_name));
1243                         break;
1244                 case LTTNG_KERNEL_KRETPROBE:
1245                         uevent_param->u.kretprobe.addr =
1246                                 old_uevent_param->u.kretprobe.addr;
1247                         uevent_param->u.kretprobe.offset =
1248                                 old_uevent_param->u.kretprobe.offset;
1249                         memcpy(uevent_param->u.kretprobe.symbol_name,
1250                                 old_uevent_param->u.kretprobe.symbol_name,
1251                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1252                         break;
1253                 case LTTNG_KERNEL_FUNCTION:
1254                         memcpy(uevent_param->u.ftrace.symbol_name,
1255                                         old_uevent_param->u.ftrace.symbol_name,
1256                                         sizeof(uevent_param->u.ftrace.symbol_name));
1257                         break;
1258                 default:
1259                         break;
1260                 }
1261                 ret = lttng_abi_create_event(file, uevent_param);
1262
1263 old_event_error_free_old_param:
1264                 kfree(old_uevent_param);
1265 old_event_error_free_param:
1266                 kfree(uevent_param);
1267 old_event_end:
1268                 return ret;
1269         }
1270         case LTTNG_KERNEL_EVENT:
1271         {
1272                 struct lttng_kernel_event uevent_param;
1273
1274                 if (copy_from_user(&uevent_param,
1275                                 (struct lttng_kernel_event __user *) arg,
1276                                 sizeof(uevent_param)))
1277                         return -EFAULT;
1278                 return lttng_abi_create_event(file, &uevent_param);
1279         }
1280         case LTTNG_KERNEL_OLD_CONTEXT:
1281         {
1282                 struct lttng_kernel_context *ucontext_param;
1283                 struct lttng_kernel_old_context *old_ucontext_param;
1284                 int ret;
1285
1286                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1287                                 GFP_KERNEL);
1288                 if (!ucontext_param) {
1289                         ret = -ENOMEM;
1290                         goto old_ctx_end;
1291                 }
1292                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1293                                 GFP_KERNEL);
1294                 if (!old_ucontext_param) {
1295                         ret = -ENOMEM;
1296                         goto old_ctx_error_free_param;
1297                 }
1298
1299                 if (copy_from_user(old_ucontext_param,
1300                                 (struct lttng_kernel_old_context __user *) arg,
1301                                 sizeof(struct lttng_kernel_old_context))) {
1302                         ret = -EFAULT;
1303                         goto old_ctx_error_free_old_param;
1304                 }
1305                 ucontext_param->ctx = old_ucontext_param->ctx;
1306                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1307                                 sizeof(ucontext_param->padding));
1308                 /* only type that uses the union */
1309                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1310                         ucontext_param->u.perf_counter.type =
1311                                 old_ucontext_param->u.perf_counter.type;
1312                         ucontext_param->u.perf_counter.config =
1313                                 old_ucontext_param->u.perf_counter.config;
1314                         memcpy(ucontext_param->u.perf_counter.name,
1315                                 old_ucontext_param->u.perf_counter.name,
1316                                 sizeof(ucontext_param->u.perf_counter.name));
1317                 }
1318
1319                 ret = lttng_abi_add_context(file,
1320                                 ucontext_param,
1321                                 &channel->ctx, channel->session);
1322
1323 old_ctx_error_free_old_param:
1324                 kfree(old_ucontext_param);
1325 old_ctx_error_free_param:
1326                 kfree(ucontext_param);
1327 old_ctx_end:
1328                 return ret;
1329         }
1330         case LTTNG_KERNEL_CONTEXT:
1331         {
1332                 struct lttng_kernel_context ucontext_param;
1333
1334                 if (copy_from_user(&ucontext_param,
1335                                 (struct lttng_kernel_context __user *) arg,
1336                                 sizeof(ucontext_param)))
1337                         return -EFAULT;
1338                 return lttng_abi_add_context(file,
1339                                 &ucontext_param,
1340                                 &channel->ctx, channel->session);
1341         }
1342         case LTTNG_KERNEL_OLD_ENABLE:
1343         case LTTNG_KERNEL_ENABLE:
1344                 return lttng_channel_enable(channel);
1345         case LTTNG_KERNEL_OLD_DISABLE:
1346         case LTTNG_KERNEL_DISABLE:
1347                 return lttng_channel_disable(channel);
1348         case LTTNG_KERNEL_SYSCALL_MASK:
1349                 return lttng_channel_syscall_mask(channel,
1350                         (struct lttng_kernel_syscall_mask __user *) arg);
1351         default:
1352                 return -ENOIOCTLCMD;
1353         }
1354 }
1355
1356 /**
1357  *      lttng_metadata_ioctl - lttng syscall through ioctl
1358  *
1359  *      @file: the file
1360  *      @cmd: the command
1361  *      @arg: command arg
1362  *
1363  *      This ioctl implements lttng commands:
1364  *      LTTNG_KERNEL_STREAM
1365  *              Returns an event stream file descriptor or failure.
1366  *
1367  * Channel and event file descriptors also hold a reference on the session.
1368  */
1369 static
1370 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1371 {
1372         switch (cmd) {
1373         case LTTNG_KERNEL_OLD_STREAM:
1374         case LTTNG_KERNEL_STREAM:
1375                 return lttng_abi_open_metadata_stream(file);
1376         default:
1377                 return -ENOIOCTLCMD;
1378         }
1379 }
1380
1381 /**
1382  *      lttng_channel_poll - lttng stream addition/removal monitoring
1383  *
1384  *      @file: the file
1385  *      @wait: poll table
1386  */
1387 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1388 {
1389         struct lttng_channel *channel = file->private_data;
1390         unsigned int mask = 0;
1391
1392         if (file->f_mode & FMODE_READ) {
1393                 poll_wait_set_exclusive(wait);
1394                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1395                           wait);
1396
1397                 if (channel->ops->is_disabled(channel->chan))
1398                         return POLLERR;
1399                 if (channel->ops->is_finalized(channel->chan))
1400                         return POLLHUP;
1401                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1402                         return POLLIN | POLLRDNORM;
1403                 return 0;
1404         }
1405         return mask;
1406
1407 }
1408
1409 static
1410 int lttng_channel_release(struct inode *inode, struct file *file)
1411 {
1412         struct lttng_channel *channel = file->private_data;
1413
1414         if (channel)
1415                 fput(channel->session->file);
1416         return 0;
1417 }
1418
1419 static
1420 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1421 {
1422         struct lttng_channel *channel = file->private_data;
1423
1424         if (channel) {
1425                 fput(channel->session->file);
1426                 lttng_metadata_channel_destroy(channel);
1427         }
1428
1429         return 0;
1430 }
1431
1432 static const struct file_operations lttng_channel_fops = {
1433         .owner = THIS_MODULE,
1434         .release = lttng_channel_release,
1435         .poll = lttng_channel_poll,
1436         .unlocked_ioctl = lttng_channel_ioctl,
1437 #ifdef CONFIG_COMPAT
1438         .compat_ioctl = lttng_channel_ioctl,
1439 #endif
1440 };
1441
1442 static const struct file_operations lttng_metadata_fops = {
1443         .owner = THIS_MODULE,
1444         .release = lttng_metadata_channel_release,
1445         .unlocked_ioctl = lttng_metadata_ioctl,
1446 #ifdef CONFIG_COMPAT
1447         .compat_ioctl = lttng_metadata_ioctl,
1448 #endif
1449 };
1450
1451 /**
1452  *      lttng_event_ioctl - lttng syscall through ioctl
1453  *
1454  *      @file: the file
1455  *      @cmd: the command
1456  *      @arg: command arg
1457  *
1458  *      This ioctl implements lttng commands:
1459  *      LTTNG_KERNEL_CONTEXT
1460  *              Prepend a context field to each record of this event
1461  *      LTTNG_KERNEL_ENABLE
1462  *              Enable recording for this event (weak enable)
1463  *      LTTNG_KERNEL_DISABLE
1464  *              Disable recording for this event (strong disable)
1465  */
1466 static
1467 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1468 {
1469         struct lttng_event *event;
1470         struct lttng_enabler *enabler;
1471         enum lttng_event_type *evtype = file->private_data;
1472
1473         switch (cmd) {
1474         case LTTNG_KERNEL_OLD_CONTEXT:
1475         {
1476                 /* Not implemented */
1477                 return -ENOSYS;
1478         }
1479         case LTTNG_KERNEL_CONTEXT:
1480         {
1481                 /* Not implemented */
1482                 return -ENOSYS;
1483         }
1484         case LTTNG_KERNEL_OLD_ENABLE:
1485         case LTTNG_KERNEL_ENABLE:
1486                 switch (*evtype) {
1487                 case LTTNG_TYPE_EVENT:
1488                         event = file->private_data;
1489                         return lttng_event_enable(event);
1490                 case LTTNG_TYPE_ENABLER:
1491                         enabler = file->private_data;
1492                         return lttng_enabler_enable(enabler);
1493                 default:
1494                         WARN_ON_ONCE(1);
1495                         return -ENOSYS;
1496                 }
1497         case LTTNG_KERNEL_OLD_DISABLE:
1498         case LTTNG_KERNEL_DISABLE:
1499                 switch (*evtype) {
1500                 case LTTNG_TYPE_EVENT:
1501                         event = file->private_data;
1502                         return lttng_event_disable(event);
1503                 case LTTNG_TYPE_ENABLER:
1504                         enabler = file->private_data;
1505                         return lttng_enabler_disable(enabler);
1506                 default:
1507                         WARN_ON_ONCE(1);
1508                         return -ENOSYS;
1509                 }
1510         case LTTNG_KERNEL_FILTER:
1511                 switch (*evtype) {
1512                 case LTTNG_TYPE_EVENT:
1513                         return -EINVAL;
1514                 case LTTNG_TYPE_ENABLER:
1515                 {
1516                         enabler = file->private_data;
1517                         return lttng_enabler_attach_bytecode(enabler,
1518                                 (struct lttng_kernel_filter_bytecode __user *) arg);
1519                 }
1520                 default:
1521                         WARN_ON_ONCE(1);
1522                         return -ENOSYS;
1523                 }
1524         case LTTNG_KERNEL_ADD_CALLSITE:
1525                 switch (*evtype) {
1526                 case LTTNG_TYPE_EVENT:
1527                         event = file->private_data;
1528                         return lttng_event_add_callsite(event,
1529                                 (struct lttng_kernel_event_callsite __user *) arg);
1530                 case LTTNG_TYPE_ENABLER:
1531                         return -EINVAL;
1532                 }
1533         default:
1534                 return -ENOIOCTLCMD;
1535         }
1536 }
1537
1538 static
1539 int lttng_event_release(struct inode *inode, struct file *file)
1540 {
1541         struct lttng_event *event;
1542         struct lttng_enabler *enabler;
1543         enum lttng_event_type *evtype = file->private_data;
1544
1545         if (!evtype)
1546                 return 0;
1547
1548         switch (*evtype) {
1549         case LTTNG_TYPE_EVENT:
1550                 event = file->private_data;
1551                 if (event)
1552                         fput(event->chan->file);
1553                 break;
1554         case LTTNG_TYPE_ENABLER:
1555                 enabler = file->private_data;
1556                 if (enabler)
1557                         fput(enabler->chan->file);
1558                 break;
1559         default:
1560                 WARN_ON_ONCE(1);
1561                 break;
1562         }
1563
1564         return 0;
1565 }
1566
1567 /* TODO: filter control ioctl */
1568 static const struct file_operations lttng_event_fops = {
1569         .owner = THIS_MODULE,
1570         .release = lttng_event_release,
1571         .unlocked_ioctl = lttng_event_ioctl,
1572 #ifdef CONFIG_COMPAT
1573         .compat_ioctl = lttng_event_ioctl,
1574 #endif
1575 };
1576
1577 static int put_u64(uint64_t val, unsigned long arg)
1578 {
1579         return put_user(val, (uint64_t __user *) arg);
1580 }
1581
1582 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1583                 unsigned int cmd, unsigned long arg)
1584 {
1585         struct lib_ring_buffer *buf = filp->private_data;
1586         struct channel *chan = buf->backend.chan;
1587         const struct lib_ring_buffer_config *config = &chan->backend.config;
1588         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1589         int ret;
1590
1591         if (atomic_read(&chan->record_disabled))
1592                 return -EIO;
1593
1594         switch (cmd) {
1595         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1596         {
1597                 uint64_t ts;
1598
1599                 ret = ops->timestamp_begin(config, buf, &ts);
1600                 if (ret < 0)
1601                         goto error;
1602                 return put_u64(ts, arg);
1603         }
1604         case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1605         {
1606                 uint64_t ts;
1607
1608                 ret = ops->timestamp_end(config, buf, &ts);
1609                 if (ret < 0)
1610                         goto error;
1611                 return put_u64(ts, arg);
1612         }
1613         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1614         {
1615                 uint64_t ed;
1616
1617                 ret = ops->events_discarded(config, buf, &ed);
1618                 if (ret < 0)
1619                         goto error;
1620                 return put_u64(ed, arg);
1621         }
1622         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1623         {
1624                 uint64_t cs;
1625
1626                 ret = ops->content_size(config, buf, &cs);
1627                 if (ret < 0)
1628                         goto error;
1629                 return put_u64(cs, arg);
1630         }
1631         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1632         {
1633                 uint64_t ps;
1634
1635                 ret = ops->packet_size(config, buf, &ps);
1636                 if (ret < 0)
1637                         goto error;
1638                 return put_u64(ps, arg);
1639         }
1640         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1641         {
1642                 uint64_t si;
1643
1644                 ret = ops->stream_id(config, buf, &si);
1645                 if (ret < 0)
1646                         goto error;
1647                 return put_u64(si, arg);
1648         }
1649         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1650         {
1651                 uint64_t ts;
1652
1653                 ret = ops->current_timestamp(config, buf, &ts);
1654                 if (ret < 0)
1655                         goto error;
1656                 return put_u64(ts, arg);
1657         }
1658         case LTTNG_RING_BUFFER_GET_SEQ_NUM:
1659         {
1660                 uint64_t seq;
1661
1662                 ret = ops->sequence_number(config, buf, &seq);
1663                 if (ret < 0)
1664                         goto error;
1665                 return put_u64(seq, arg);
1666         }
1667         case LTTNG_RING_BUFFER_INSTANCE_ID:
1668         {
1669                 uint64_t id;
1670
1671                 ret = ops->instance_id(config, buf, &id);
1672                 if (ret < 0)
1673                         goto error;
1674                 return put_u64(id, arg);
1675         }
1676         default:
1677                 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1678                                 cmd, arg);
1679         }
1680
1681 error:
1682         return -ENOSYS;
1683 }
1684
1685 #ifdef CONFIG_COMPAT
1686 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1687                 unsigned int cmd, unsigned long arg)
1688 {
1689         struct lib_ring_buffer *buf = filp->private_data;
1690         struct channel *chan = buf->backend.chan;
1691         const struct lib_ring_buffer_config *config = &chan->backend.config;
1692         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1693         int ret;
1694
1695         if (atomic_read(&chan->record_disabled))
1696                 return -EIO;
1697
1698         switch (cmd) {
1699         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1700         {
1701                 uint64_t ts;
1702
1703                 ret = ops->timestamp_begin(config, buf, &ts);
1704                 if (ret < 0)
1705                         goto error;
1706                 return put_u64(ts, arg);
1707         }
1708         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1709         {
1710                 uint64_t ts;
1711
1712                 ret = ops->timestamp_end(config, buf, &ts);
1713                 if (ret < 0)
1714                         goto error;
1715                 return put_u64(ts, arg);
1716         }
1717         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1718         {
1719                 uint64_t ed;
1720
1721                 ret = ops->events_discarded(config, buf, &ed);
1722                 if (ret < 0)
1723                         goto error;
1724                 return put_u64(ed, arg);
1725         }
1726         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1727         {
1728                 uint64_t cs;
1729
1730                 ret = ops->content_size(config, buf, &cs);
1731                 if (ret < 0)
1732                         goto error;
1733                 return put_u64(cs, arg);
1734         }
1735         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1736         {
1737                 uint64_t ps;
1738
1739                 ret = ops->packet_size(config, buf, &ps);
1740                 if (ret < 0)
1741                         goto error;
1742                 return put_u64(ps, arg);
1743         }
1744         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1745         {
1746                 uint64_t si;
1747
1748                 ret = ops->stream_id(config, buf, &si);
1749                 if (ret < 0)
1750                         goto error;
1751                 return put_u64(si, arg);
1752         }
1753         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1754         {
1755                 uint64_t ts;
1756
1757                 ret = ops->current_timestamp(config, buf, &ts);
1758                 if (ret < 0)
1759                         goto error;
1760                 return put_u64(ts, arg);
1761         }
1762         case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
1763         {
1764                 uint64_t seq;
1765
1766                 ret = ops->sequence_number(config, buf, &seq);
1767                 if (ret < 0)
1768                         goto error;
1769                 return put_u64(seq, arg);
1770         }
1771         case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
1772         {
1773                 uint64_t id;
1774
1775                 ret = ops->instance_id(config, buf, &id);
1776                 if (ret < 0)
1777                         goto error;
1778                 return put_u64(id, arg);
1779         }
1780         default:
1781                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1782                                 cmd, arg);
1783         }
1784
1785 error:
1786         return -ENOSYS;
1787 }
1788 #endif /* CONFIG_COMPAT */
1789
1790 static void lttng_stream_override_ring_buffer_fops(void)
1791 {
1792         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1793         lttng_stream_ring_buffer_file_operations.open =
1794                 lib_ring_buffer_file_operations.open;
1795         lttng_stream_ring_buffer_file_operations.release =
1796                 lib_ring_buffer_file_operations.release;
1797         lttng_stream_ring_buffer_file_operations.poll =
1798                 lib_ring_buffer_file_operations.poll;
1799         lttng_stream_ring_buffer_file_operations.splice_read =
1800                 lib_ring_buffer_file_operations.splice_read;
1801         lttng_stream_ring_buffer_file_operations.mmap =
1802                 lib_ring_buffer_file_operations.mmap;
1803         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1804                 lttng_stream_ring_buffer_ioctl;
1805         lttng_stream_ring_buffer_file_operations.llseek =
1806                 lib_ring_buffer_file_operations.llseek;
1807 #ifdef CONFIG_COMPAT
1808         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1809                 lttng_stream_ring_buffer_compat_ioctl;
1810 #endif
1811 }
1812
1813 int __init lttng_abi_init(void)
1814 {
1815         int ret = 0;
1816
1817         wrapper_vmalloc_sync_all();
1818         lttng_clock_ref();
1819
1820         ret = lttng_tp_mempool_init();
1821         if (ret) {
1822                 goto error;
1823         }
1824
1825         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1826                                         &lttng_fops, NULL);
1827
1828         if (!lttng_proc_dentry) {
1829                 printk(KERN_ERR "Error creating LTTng control file\n");
1830                 ret = -ENOMEM;
1831                 goto error;
1832         }
1833         lttng_stream_override_ring_buffer_fops();
1834         return 0;
1835
1836 error:
1837         lttng_tp_mempool_destroy();
1838         lttng_clock_unref();
1839         return ret;
1840 }
1841
1842 /* No __exit annotation because used by init error path too. */
1843 void lttng_abi_exit(void)
1844 {
1845         lttng_tp_mempool_destroy();
1846         lttng_clock_unref();
1847         if (lttng_proc_dentry)
1848                 remove_proc_entry("lttng", NULL);
1849 }