lttng-abi.c

   1 /*
   2  * lttng-abi.c
   3  *
   4  * LTTng ABI
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  *
  22  *
  23  * Mimic system calls for:
  24  * - session creation, returns a file descriptor or failure.
  25  *   - channel creation, returns a file descriptor or failure.
  26  *     - Operates on a session file descriptor
  27  *     - Takes all channel options as parameters.
  28  *   - stream get, returns a file descriptor or failure.
  29  *     - Operates on a channel file descriptor.
  30  *   - stream notifier get, returns a file descriptor or failure.
  31  *     - Operates on a channel file descriptor.
  32  *   - event creation, returns a file descriptor or failure.
  33  *     - Operates on a channel file descriptor
  34  *     - Takes an event name as parameter
  35  *     - Takes an instrumentation source as parameter
  36  *       - e.g. tracepoints, dynamic_probes...
  37  *     - Takes instrumentation source specific arguments.
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/proc_fs.h>
  42 #include <linux/anon_inodes.h>
  43 #include <linux/file.h>
  44 #include <linux/uaccess.h>
  45 #include <linux/slab.h>
  46 #include <linux/err.h>
  47 #include "wrapper/vmalloc.h"    /* for wrapper_vmalloc_sync_all() */
  48 #include "wrapper/ringbuffer/vfs.h"
  49 #include "wrapper/ringbuffer/backend.h"
  50 #include "wrapper/ringbuffer/frontend.h"
  51 #include "wrapper/poll.h"
  52 #include "lttng-abi.h"
  53 #include "lttng-abi-old.h"
  54 #include "lttng-events.h"
  55 #include "lttng-tracer.h"
  56 #include "lib/ringbuffer/frontend_types.h"
  57
  58 /*
  59  * This is LTTng's own personal way to create a system call as an external
  60  * module. We use ioctl() on /proc/lttng.
  61  */
  62
  63 static struct proc_dir_entry *lttng_proc_dentry;
  64 static const struct file_operations lttng_fops;
  65 static const struct file_operations lttng_session_fops;
  66 static const struct file_operations lttng_channel_fops;
  67 static const struct file_operations lttng_metadata_fops;
  68 static const struct file_operations lttng_event_fops;
  69 static struct file_operations lttng_stream_ring_buffer_file_operations;
  70
  71 /*
  72  * Teardown management: opened file descriptors keep a refcount on the module,
  73  * so it can only exit when all file descriptors are closed.
  74  */
  75
  76 static
  77 int lttng_abi_create_session(void)
  78 {
  79         struct lttng_session *session;
  80         struct file *session_file;
  81         int session_fd, ret;
  82
  83         session = lttng_session_create();
  84         if (!session)
  85                 return -ENOMEM;
  86         session_fd = get_unused_fd();
  87         if (session_fd < 0) {
  88                 ret = session_fd;
  89                 goto fd_error;
  90         }
  91         session_file = anon_inode_getfile("[lttng_session]",
  92                                           &lttng_session_fops,
  93                                           session, O_RDWR);
  94         if (IS_ERR(session_file)) {
  95                 ret = PTR_ERR(session_file);
  96                 goto file_error;
  97         }
  98         session->file = session_file;
  99         fd_install(session_fd, session_file);
 100         return session_fd;
 101
 102 file_error:
 103         put_unused_fd(session_fd);
 104 fd_error:
 105         lttng_session_destroy(session);
 106         return ret;
 107 }
 108
 109 static
 110 int lttng_abi_tracepoint_list(void)
 111 {
 112         struct file *tracepoint_list_file;
 113         int file_fd, ret;
 114
 115         file_fd = get_unused_fd();
 116         if (file_fd < 0) {
 117                 ret = file_fd;
 118                 goto fd_error;
 119         }
 120
 121         tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
 122                                           &lttng_tracepoint_list_fops,
 123                                           NULL, O_RDWR);
 124         if (IS_ERR(tracepoint_list_file)) {
 125                 ret = PTR_ERR(tracepoint_list_file);
 126                 goto file_error;
 127         }
 128         ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
 129         if (ret < 0)
 130                 goto open_error;
 131         fd_install(file_fd, tracepoint_list_file);
 132         if (file_fd < 0) {
 133                 ret = file_fd;
 134                 goto fd_error;
 135         }
 136         return file_fd;
 137
 138 open_error:
 139         fput(tracepoint_list_file);
 140 file_error:
 141         put_unused_fd(file_fd);
 142 fd_error:
 143         return ret;
 144 }
 145
 146 static
 147 int lttng_abi_syscall_list(void)
 148 {
 149         struct file *syscall_list_file;
 150         int file_fd, ret;
 151
 152         file_fd = get_unused_fd();
 153         if (file_fd < 0) {
 154                 ret = file_fd;
 155                 goto fd_error;
 156         }
 157
 158         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
 159                                           &lttng_syscall_list_fops,
 160                                           NULL, O_RDWR);
 161         if (IS_ERR(syscall_list_file)) {
 162                 ret = PTR_ERR(syscall_list_file);
 163                 goto file_error;
 164         }
 165         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
 166         if (ret < 0)
 167                 goto open_error;
 168         fd_install(file_fd, syscall_list_file);
 169         if (file_fd < 0) {
 170                 ret = file_fd;
 171                 goto fd_error;
 172         }
 173         return file_fd;
 174
 175 open_error:
 176         fput(syscall_list_file);
 177 file_error:
 178         put_unused_fd(file_fd);
 179 fd_error:
 180         return ret;
 181 }
 182
 183 static
 184 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
 185 {
 186         v->major = LTTNG_MODULES_MAJOR_VERSION;
 187         v->minor = LTTNG_MODULES_MINOR_VERSION;
 188         v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
 189 }
 190
 191 static
 192 void lttng_abi_tracer_abi_version(struct lttng_kernel_tracer_abi_version *v)
 193 {
 194         v->major = LTTNG_MODULES_ABI_MAJOR_VERSION;
 195         v->minor = LTTNG_MODULES_ABI_MINOR_VERSION;
 196 }
 197
 198 static
 199 long lttng_abi_add_context(struct file *file,
 200         struct lttng_kernel_context *context_param,
 201         struct lttng_ctx **ctx, struct lttng_session *session)
 202 {
 203
 204         if (session->been_active)
 205                 return -EPERM;
 206
 207         switch (context_param->ctx) {
 208         case LTTNG_KERNEL_CONTEXT_PID:
 209                 return lttng_add_pid_to_ctx(ctx);
 210         case LTTNG_KERNEL_CONTEXT_PRIO:
 211                 return lttng_add_prio_to_ctx(ctx);
 212         case LTTNG_KERNEL_CONTEXT_NICE:
 213                 return lttng_add_nice_to_ctx(ctx);
 214         case LTTNG_KERNEL_CONTEXT_VPID:
 215                 return lttng_add_vpid_to_ctx(ctx);
 216         case LTTNG_KERNEL_CONTEXT_TID:
 217                 return lttng_add_tid_to_ctx(ctx);
 218         case LTTNG_KERNEL_CONTEXT_VTID:
 219                 return lttng_add_vtid_to_ctx(ctx);
 220         case LTTNG_KERNEL_CONTEXT_PPID:
 221                 return lttng_add_ppid_to_ctx(ctx);
 222         case LTTNG_KERNEL_CONTEXT_VPPID:
 223                 return lttng_add_vppid_to_ctx(ctx);
 224         case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
 225                 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 226                 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
 227                                 context_param->u.perf_counter.config,
 228                                 context_param->u.perf_counter.name,
 229                                 ctx);
 230         case LTTNG_KERNEL_CONTEXT_PROCNAME:
 231                 return lttng_add_procname_to_ctx(ctx);
 232         case LTTNG_KERNEL_CONTEXT_HOSTNAME:
 233                 return lttng_add_hostname_to_ctx(ctx);
 234         default:
 235                 return -EINVAL;
 236         }
 237 }
 238
 239 /**
 240  *      lttng_ioctl - lttng syscall through ioctl
 241  *
 242  *      @file: the file
 243  *      @cmd: the command
 244  *      @arg: command arg
 245  *
 246  *      This ioctl implements lttng commands:
 247  *      LTTNG_KERNEL_SESSION
 248  *              Returns a LTTng trace session file descriptor
 249  *      LTTNG_KERNEL_TRACER_VERSION
 250  *              Returns the LTTng kernel tracer version
 251  *      LTTNG_KERNEL_TRACEPOINT_LIST
 252  *              Returns a file descriptor listing available tracepoints
 253  *      LTTNG_KERNEL_WAIT_QUIESCENT
 254  *              Returns after all previously running probes have completed
 255  *      LTTNG_KERNEL_TRACER_ABI_VERSION
 256  *              Returns the LTTng kernel tracer ABI version
 257  *
 258  * The returned session will be deleted when its file descriptor is closed.
 259  */
 260 static
 261 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 262 {
 263         switch (cmd) {
 264         case LTTNG_KERNEL_OLD_SESSION:
 265         case LTTNG_KERNEL_SESSION:
 266                 return lttng_abi_create_session();
 267         case LTTNG_KERNEL_OLD_TRACER_VERSION:
 268         {
 269                 struct lttng_kernel_tracer_version v;
 270                 struct lttng_kernel_old_tracer_version oldv;
 271                 struct lttng_kernel_old_tracer_version *uversion =
 272                         (struct lttng_kernel_old_tracer_version __user *) arg;
 273
 274                 lttng_abi_tracer_version(&v);
 275                 oldv.major = v.major;
 276                 oldv.minor = v.minor;
 277                 oldv.patchlevel = v.patchlevel;
 278
 279                 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
 280                         return -EFAULT;
 281                 return 0;
 282         }
 283         case LTTNG_KERNEL_TRACER_VERSION:
 284         {
 285                 struct lttng_kernel_tracer_version version;
 286                 struct lttng_kernel_tracer_version *uversion =
 287                         (struct lttng_kernel_tracer_version __user *) arg;
 288
 289                 lttng_abi_tracer_version(&version);
 290
 291                 if (copy_to_user(uversion, &version, sizeof(version)))
 292                         return -EFAULT;
 293                 return 0;
 294         }
 295         case LTTNG_KERNEL_TRACER_ABI_VERSION:
 296         {
 297                 struct lttng_kernel_tracer_abi_version version;
 298                 struct lttng_kernel_tracer_abi_version *uversion =
 299                         (struct lttng_kernel_tracer_abi_version __user *) arg;
 300
 301                 lttng_abi_tracer_abi_version(&version);
 302
 303                 if (copy_to_user(uversion, &version, sizeof(version)))
 304                         return -EFAULT;
 305                 return 0;
 306         }
 307         case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
 308         case LTTNG_KERNEL_TRACEPOINT_LIST:
 309                 return lttng_abi_tracepoint_list();
 310         case LTTNG_KERNEL_SYSCALL_LIST:
 311                 return lttng_abi_syscall_list();
 312         case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
 313         case LTTNG_KERNEL_WAIT_QUIESCENT:
 314                 synchronize_trace();
 315                 return 0;
 316         case LTTNG_KERNEL_OLD_CALIBRATE:
 317         {
 318                 struct lttng_kernel_old_calibrate __user *ucalibrate =
 319                         (struct lttng_kernel_old_calibrate __user *) arg;
 320                 struct lttng_kernel_old_calibrate old_calibrate;
 321                 struct lttng_kernel_calibrate calibrate;
 322                 int ret;
 323
 324                 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
 325                         return -EFAULT;
 326                 calibrate.type = old_calibrate.type;
 327                 ret = lttng_calibrate(&calibrate);
 328                 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
 329                         return -EFAULT;
 330                 return ret;
 331         }
 332         case LTTNG_KERNEL_CALIBRATE:
 333         {
 334                 struct lttng_kernel_calibrate __user *ucalibrate =
 335                         (struct lttng_kernel_calibrate __user *) arg;
 336                 struct lttng_kernel_calibrate calibrate;
 337                 int ret;
 338
 339                 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
 340                         return -EFAULT;
 341                 ret = lttng_calibrate(&calibrate);
 342                 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
 343                         return -EFAULT;
 344                 return ret;
 345         }
 346         default:
 347                 return -ENOIOCTLCMD;
 348         }
 349 }
 350
 351 static const struct file_operations lttng_fops = {
 352         .owner = THIS_MODULE,
 353         .unlocked_ioctl = lttng_ioctl,
 354 #ifdef CONFIG_COMPAT
 355         .compat_ioctl = lttng_ioctl,
 356 #endif
 357 };
 358
 359 static
 360 int lttng_abi_create_channel(struct file *session_file,
 361                              struct lttng_kernel_channel *chan_param,
 362                              enum channel_type channel_type)
 363 {
 364         struct lttng_session *session = session_file->private_data;
 365         const struct file_operations *fops = NULL;
 366         const char *transport_name;
 367         struct lttng_channel *chan;
 368         struct file *chan_file;
 369         int chan_fd;
 370         int ret = 0;
 371
 372         chan_fd = get_unused_fd();
 373         if (chan_fd < 0) {
 374                 ret = chan_fd;
 375                 goto fd_error;
 376         }
 377         switch (channel_type) {
 378         case PER_CPU_CHANNEL:
 379                 fops = &lttng_channel_fops;
 380                 break;
 381         case METADATA_CHANNEL:
 382                 fops = &lttng_metadata_fops;
 383                 break;
 384         }
 385
 386         chan_file = anon_inode_getfile("[lttng_channel]",
 387                                        fops,
 388                                        NULL, O_RDWR);
 389         if (IS_ERR(chan_file)) {
 390                 ret = PTR_ERR(chan_file);
 391                 goto file_error;
 392         }
 393         switch (channel_type) {
 394         case PER_CPU_CHANNEL:
 395                 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
 396                         transport_name = chan_param->overwrite ?
 397                                 "relay-overwrite" : "relay-discard";
 398                 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
 399                         transport_name = chan_param->overwrite ?
 400                                 "relay-overwrite-mmap" : "relay-discard-mmap";
 401                 } else {
 402                         return -EINVAL;
 403                 }
 404                 break;
 405         case METADATA_CHANNEL:
 406                 if (chan_param->output == LTTNG_KERNEL_SPLICE)
 407                         transport_name = "relay-metadata";
 408                 else if (chan_param->output == LTTNG_KERNEL_MMAP)
 409                         transport_name = "relay-metadata-mmap";
 410                 else
 411                         return -EINVAL;
 412                 break;
 413         default:
 414                 transport_name = "<unknown>";
 415                 break;
 416         }
 417         /*
 418          * We tolerate no failure path after channel creation. It will stay
 419          * invariant for the rest of the session.
 420          */
 421         chan = lttng_channel_create(session, transport_name, NULL,
 422                                   chan_param->subbuf_size,
 423                                   chan_param->num_subbuf,
 424                                   chan_param->switch_timer_interval,
 425                                   chan_param->read_timer_interval,
 426                                   channel_type);
 427         if (!chan) {
 428                 ret = -EINVAL;
 429                 goto chan_error;
 430         }
 431         chan->file = chan_file;
 432         chan_file->private_data = chan;
 433         fd_install(chan_fd, chan_file);
 434         atomic_long_inc(&session_file->f_count);
 435
 436         return chan_fd;
 437
 438 chan_error:
 439         fput(chan_file);
 440 file_error:
 441         put_unused_fd(chan_fd);
 442 fd_error:
 443         return ret;
 444 }
 445
 446 /**
 447  *      lttng_session_ioctl - lttng session fd ioctl
 448  *
 449  *      @file: the file
 450  *      @cmd: the command
 451  *      @arg: command arg
 452  *
 453  *      This ioctl implements lttng commands:
 454  *      LTTNG_KERNEL_CHANNEL
 455  *              Returns a LTTng channel file descriptor
 456  *      LTTNG_KERNEL_ENABLE
 457  *              Enables tracing for a session (weak enable)
 458  *      LTTNG_KERNEL_DISABLE
 459  *              Disables tracing for a session (strong disable)
 460  *      LTTNG_KERNEL_METADATA
 461  *              Returns a LTTng metadata file descriptor
 462  *
 463  * The returned channel will be deleted when its file descriptor is closed.
 464  */
 465 static
 466 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 467 {
 468         struct lttng_session *session = file->private_data;
 469
 470         switch (cmd) {
 471         case LTTNG_KERNEL_OLD_CHANNEL:
 472         {
 473                 struct lttng_kernel_channel chan_param;
 474                 struct lttng_kernel_old_channel old_chan_param;
 475
 476                 if (copy_from_user(&old_chan_param,
 477                                 (struct lttng_kernel_old_channel __user *) arg,
 478                                 sizeof(struct lttng_kernel_old_channel)))
 479                         return -EFAULT;
 480                 chan_param.overwrite = old_chan_param.overwrite;
 481                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 482                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 483                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 484                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 485                 chan_param.output = old_chan_param.output;
 486
 487                 return lttng_abi_create_channel(file, &chan_param,
 488                                 PER_CPU_CHANNEL);
 489         }
 490         case LTTNG_KERNEL_CHANNEL:
 491         {
 492                 struct lttng_kernel_channel chan_param;
 493
 494                 if (copy_from_user(&chan_param,
 495                                 (struct lttng_kernel_channel __user *) arg,
 496                                 sizeof(struct lttng_kernel_channel)))
 497                         return -EFAULT;
 498                 return lttng_abi_create_channel(file, &chan_param,
 499                                 PER_CPU_CHANNEL);
 500         }
 501         case LTTNG_KERNEL_OLD_SESSION_START:
 502         case LTTNG_KERNEL_OLD_ENABLE:
 503         case LTTNG_KERNEL_SESSION_START:
 504         case LTTNG_KERNEL_ENABLE:
 505                 return lttng_session_enable(session);
 506         case LTTNG_KERNEL_OLD_SESSION_STOP:
 507         case LTTNG_KERNEL_OLD_DISABLE:
 508         case LTTNG_KERNEL_SESSION_STOP:
 509         case LTTNG_KERNEL_DISABLE:
 510                 return lttng_session_disable(session);
 511         case LTTNG_KERNEL_OLD_METADATA:
 512         {
 513                 struct lttng_kernel_channel chan_param;
 514                 struct lttng_kernel_old_channel old_chan_param;
 515
 516                 if (copy_from_user(&old_chan_param,
 517                                 (struct lttng_kernel_old_channel __user *) arg,
 518                                 sizeof(struct lttng_kernel_old_channel)))
 519                         return -EFAULT;
 520                 chan_param.overwrite = old_chan_param.overwrite;
 521                 chan_param.subbuf_size = old_chan_param.subbuf_size;
 522                 chan_param.num_subbuf = old_chan_param.num_subbuf;
 523                 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
 524                 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
 525                 chan_param.output = old_chan_param.output;
 526
 527                 return lttng_abi_create_channel(file, &chan_param,
 528                                 METADATA_CHANNEL);
 529         }
 530         case LTTNG_KERNEL_METADATA:
 531         {
 532                 struct lttng_kernel_channel chan_param;
 533
 534                 if (copy_from_user(&chan_param,
 535                                         (struct lttng_kernel_channel __user *) arg,
 536                                         sizeof(struct lttng_kernel_channel)))
 537                         return -EFAULT;
 538                 return lttng_abi_create_channel(file, &chan_param,
 539                                 METADATA_CHANNEL);
 540         }
 541         default:
 542                 return -ENOIOCTLCMD;
 543         }
 544 }
 545
 546 /*
 547  * Called when the last file reference is dropped.
 548  *
 549  * Big fat note: channels and events are invariant for the whole session after
 550  * their creation. So this session destruction also destroys all channel and
 551  * event structures specific to this session (they are not destroyed when their
 552  * individual file is released).
 553  */
 554 static
 555 int lttng_session_release(struct inode *inode, struct file *file)
 556 {
 557         struct lttng_session *session = file->private_data;
 558
 559         if (session)
 560                 lttng_session_destroy(session);
 561         return 0;
 562 }
 563
 564 static const struct file_operations lttng_session_fops = {
 565         .owner = THIS_MODULE,
 566         .release = lttng_session_release,
 567         .unlocked_ioctl = lttng_session_ioctl,
 568 #ifdef CONFIG_COMPAT
 569         .compat_ioctl = lttng_session_ioctl,
 570 #endif
 571 };
 572
 573 /**
 574  *      lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
 575  *      @filp: the file
 576  *      @wait: poll table
 577  *
 578  *      Handles the poll operations for the metadata channels.
 579  */
 580 static
 581 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
 582                 poll_table *wait)
 583 {
 584         struct lttng_metadata_stream *stream = filp->private_data;
 585         struct lib_ring_buffer *buf = stream->priv;
 586         int finalized;
 587         unsigned int mask = 0;
 588
 589         if (filp->f_mode & FMODE_READ) {
 590                 poll_wait_set_exclusive(wait);
 591                 poll_wait(filp, &stream->read_wait, wait);
 592
 593                 finalized = stream->finalized;
 594
 595                 /*
 596                  * lib_ring_buffer_is_finalized() contains a smp_rmb()
 597                  * ordering finalized load before offsets loads.
 598                  */
 599                 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
 600
 601                 if (finalized)
 602                         mask |= POLLHUP;
 603
 604                 if (stream->metadata_cache->metadata_written >
 605                                 stream->metadata_out)
 606                         mask |= POLLIN;
 607         }
 608
 609         return mask;
 610 }
 611
 612 static
 613 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
 614                 unsigned int cmd, unsigned long arg)
 615 {
 616         struct lttng_metadata_stream *stream = filp->private_data;
 617
 618         stream->metadata_out = stream->metadata_in;
 619 }
 620
 621 static
 622 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 623                 unsigned int cmd, unsigned long arg)
 624 {
 625         int ret;
 626         struct lttng_metadata_stream *stream = filp->private_data;
 627         struct lib_ring_buffer *buf = stream->priv;
 628
 629         switch (cmd) {
 630         case RING_BUFFER_GET_NEXT_SUBBUF:
 631         {
 632                 struct lttng_metadata_stream *stream = filp->private_data;
 633                 struct lib_ring_buffer *buf = stream->priv;
 634                 struct channel *chan = buf->backend.chan;
 635
 636                 ret = lttng_metadata_output_channel(stream, chan);
 637                 if (ret > 0) {
 638                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 639                         ret = 0;
 640                 } else if (ret < 0)
 641                         goto err;
 642                 break;
 643         }
 644         case RING_BUFFER_GET_SUBBUF:
 645         {
 646                 /*
 647                  * Random access is not allowed for metadata channel.
 648                  */
 649                 return -ENOSYS;
 650         }
 651         case RING_BUFFER_FLUSH:
 652         {
 653                 struct lttng_metadata_stream *stream = filp->private_data;
 654                 struct lib_ring_buffer *buf = stream->priv;
 655                 struct channel *chan = buf->backend.chan;
 656
 657                 /*
 658                  * Before doing the actual ring buffer flush, write up to one
 659                  * packet of metadata in the ring buffer.
 660                  */
 661                 ret = lttng_metadata_output_channel(stream, chan);
 662                 if (ret < 0)
 663                         goto err;
 664                 break;
 665         }
 666         default:
 667                 break;
 668         }
 669         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 670
 671         /* Performing lib ring buffer ioctl after our own. */
 672         ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
 673         if (ret < 0)
 674                 goto err;
 675
 676         switch (cmd) {
 677         case RING_BUFFER_PUT_NEXT_SUBBUF:
 678         {
 679                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 680                                 cmd, arg);
 681                 break;
 682         }
 683         default:
 684                 break;
 685         }
 686 err:
 687         return ret;
 688 }
 689
 690 #ifdef CONFIG_COMPAT
 691 static
 692 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 693                 unsigned int cmd, unsigned long arg)
 694 {
 695         int ret;
 696         struct lttng_metadata_stream *stream = filp->private_data;
 697         struct lib_ring_buffer *buf = stream->priv;
 698
 699         switch (cmd) {
 700         case RING_BUFFER_GET_NEXT_SUBBUF:
 701         {
 702                 struct lttng_metadata_stream *stream = filp->private_data;
 703                 struct lib_ring_buffer *buf = stream->priv;
 704                 struct channel *chan = buf->backend.chan;
 705
 706                 ret = lttng_metadata_output_channel(stream, chan);
 707                 if (ret > 0) {
 708                         lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
 709                         ret = 0;
 710                 } else if (ret < 0)
 711                         goto err;
 712                 break;
 713         }
 714         case RING_BUFFER_GET_SUBBUF:
 715         {
 716                 /*
 717                  * Random access is not allowed for metadata channel.
 718                  */
 719                 return -ENOSYS;
 720         }
 721         default:
 722                 break;
 723         }
 724         /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
 725
 726         /* Performing lib ring buffer ioctl after our own. */
 727         ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
 728         if (ret < 0)
 729                 goto err;
 730
 731         switch (cmd) {
 732         case RING_BUFFER_PUT_NEXT_SUBBUF:
 733         {
 734                 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
 735                                 cmd, arg);
 736                 break;
 737         }
 738         default:
 739                 break;
 740         }
 741 err:
 742         return ret;
 743 }
 744 #endif
 745
 746 /*
 747  * This is not used by anonymous file descriptors. This code is left
 748  * there if we ever want to implement an inode with open() operation.
 749  */
 750 static
 751 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
 752 {
 753         struct lttng_metadata_stream *stream = inode->i_private;
 754         struct lib_ring_buffer *buf = stream->priv;
 755
 756         file->private_data = buf;
 757         /*
 758          * Since life-time of metadata cache differs from that of
 759          * session, we need to keep our own reference on the transport.
 760          */
 761         if (!try_module_get(stream->transport->owner)) {
 762                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 763                 return -EBUSY;
 764         }
 765         return lib_ring_buffer_open(inode, file, buf);
 766 }
 767
 768 static
 769 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
 770 {
 771         struct lttng_metadata_stream *stream = file->private_data;
 772         struct lib_ring_buffer *buf = stream->priv;
 773
 774         kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
 775         module_put(stream->transport->owner);
 776         return lib_ring_buffer_release(inode, file, buf);
 777 }
 778
 779 static
 780 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
 781                 struct pipe_inode_info *pipe, size_t len,
 782                 unsigned int flags)
 783 {
 784         struct lttng_metadata_stream *stream = in->private_data;
 785         struct lib_ring_buffer *buf = stream->priv;
 786
 787         return lib_ring_buffer_splice_read(in, ppos, pipe, len,
 788                         flags, buf);
 789 }
 790
 791 static
 792 int lttng_metadata_ring_buffer_mmap(struct file *filp,
 793                 struct vm_area_struct *vma)
 794 {
 795         struct lttng_metadata_stream *stream = filp->private_data;
 796         struct lib_ring_buffer *buf = stream->priv;
 797
 798         return lib_ring_buffer_mmap(filp, vma, buf);
 799 }
 800
 801 static
 802 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
 803         .owner = THIS_MODULE,
 804         .open = lttng_metadata_ring_buffer_open,
 805         .release = lttng_metadata_ring_buffer_release,
 806         .poll = lttng_metadata_ring_buffer_poll,
 807         .splice_read = lttng_metadata_ring_buffer_splice_read,
 808         .mmap = lttng_metadata_ring_buffer_mmap,
 809         .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
 810         .llseek = vfs_lib_ring_buffer_no_llseek,
 811 #ifdef CONFIG_COMPAT
 812         .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
 813 #endif
 814 };
 815
 816 static
 817 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
 818                 const struct file_operations *fops)
 819 {
 820         int stream_fd, ret;
 821         struct file *stream_file;
 822
 823         stream_fd = get_unused_fd();
 824         if (stream_fd < 0) {
 825                 ret = stream_fd;
 826                 goto fd_error;
 827         }
 828         stream_file = anon_inode_getfile("[lttng_stream]", fops,
 829                         stream_priv, O_RDWR);
 830         if (IS_ERR(stream_file)) {
 831                 ret = PTR_ERR(stream_file);
 832                 goto file_error;
 833         }
 834         /*
 835          * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
 836          * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
 837          * file descriptor, so we set FMODE_PREAD here.
 838          */
 839         stream_file->f_mode |= FMODE_PREAD;
 840         fd_install(stream_fd, stream_file);
 841         /*
 842          * The stream holds a reference to the channel within the generic ring
 843          * buffer library, so no need to hold a refcount on the channel and
 844          * session files here.
 845          */
 846         return stream_fd;
 847
 848 file_error:
 849         put_unused_fd(stream_fd);
 850 fd_error:
 851         return ret;
 852 }
 853
 854 static
 855 int lttng_abi_open_stream(struct file *channel_file)
 856 {
 857         struct lttng_channel *channel = channel_file->private_data;
 858         struct lib_ring_buffer *buf;
 859         int ret;
 860         void *stream_priv;
 861
 862         buf = channel->ops->buffer_read_open(channel->chan);
 863         if (!buf)
 864                 return -ENOENT;
 865
 866         stream_priv = buf;
 867         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 868                         &lttng_stream_ring_buffer_file_operations);
 869         if (ret < 0)
 870                 goto fd_error;
 871
 872         return ret;
 873
 874 fd_error:
 875         channel->ops->buffer_read_close(buf);
 876         return ret;
 877 }
 878
 879 static
 880 int lttng_abi_open_metadata_stream(struct file *channel_file)
 881 {
 882         struct lttng_channel *channel = channel_file->private_data;
 883         struct lttng_session *session = channel->session;
 884         struct lib_ring_buffer *buf;
 885         int ret;
 886         struct lttng_metadata_stream *metadata_stream;
 887         void *stream_priv;
 888
 889         buf = channel->ops->buffer_read_open(channel->chan);
 890         if (!buf)
 891                 return -ENOENT;
 892
 893         metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
 894                         GFP_KERNEL);
 895         if (!metadata_stream) {
 896                 ret = -ENOMEM;
 897                 goto nomem;
 898         }
 899         metadata_stream->metadata_cache = session->metadata_cache;
 900         init_waitqueue_head(&metadata_stream->read_wait);
 901         metadata_stream->priv = buf;
 902         stream_priv = metadata_stream;
 903         metadata_stream->transport = channel->transport;
 904         mutex_init(&metadata_stream->lock);
 905
 906         /*
 907          * Since life-time of metadata cache differs from that of
 908          * session, we need to keep our own reference on the transport.
 909          */
 910         if (!try_module_get(metadata_stream->transport->owner)) {
 911                 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
 912                 ret = -EINVAL;
 913                 goto notransport;
 914         }
 915
 916         ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
 917                         &lttng_metadata_ring_buffer_file_operations);
 918         if (ret < 0)
 919                 goto fd_error;
 920
 921         kref_get(&session->metadata_cache->refcount);
 922         list_add(&metadata_stream->list,
 923                 &session->metadata_cache->metadata_stream);
 924         return ret;
 925
 926 fd_error:
 927         module_put(metadata_stream->transport->owner);
 928 notransport:
 929         kfree(metadata_stream);
 930 nomem:
 931         channel->ops->buffer_read_close(buf);
 932         return ret;
 933 }
 934
 935 static
 936 int lttng_abi_create_event(struct file *channel_file,
 937                            struct lttng_kernel_event *event_param)
 938 {
 939         struct lttng_channel *channel = channel_file->private_data;
 940         struct lttng_event *event;
 941         int event_fd, ret;
 942         struct file *event_file;
 943
 944         event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 945         switch (event_param->instrumentation) {
 946         case LTTNG_KERNEL_KRETPROBE:
 947                 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 948                 break;
 949         case LTTNG_KERNEL_KPROBE:
 950                 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 951                 break;
 952         case LTTNG_KERNEL_FUNCTION:
 953                 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 954                 break;
 955         default:
 956                 break;
 957         }
 958         switch (event_param->instrumentation) {
 959         default:
 960                 event_fd = get_unused_fd();
 961                 if (event_fd < 0) {
 962                         ret = event_fd;
 963                         goto fd_error;
 964                 }
 965                 event_file = anon_inode_getfile("[lttng_event]",
 966                                                 &lttng_event_fops,
 967                                                 NULL, O_RDWR);
 968                 if (IS_ERR(event_file)) {
 969                         ret = PTR_ERR(event_file);
 970                         goto file_error;
 971                 }
 972                 /*
 973                  * We tolerate no failure path after event creation. It
 974                  * will stay invariant for the rest of the session.
 975                  */
 976                 event = lttng_event_create(channel, event_param, NULL, NULL);
 977                 WARN_ON_ONCE(!event);
 978                 if (IS_ERR(event)) {
 979                         ret = PTR_ERR(event);
 980                         goto event_error;
 981                 }
 982                 event_file->private_data = event;
 983                 fd_install(event_fd, event_file);
 984                 /* The event holds a reference on the channel */
 985                 atomic_long_inc(&channel_file->f_count);
 986                 break;
 987         case LTTNG_KERNEL_SYSCALL:
 988                 ret = lttng_syscalls_register(channel, NULL);
 989                 if (ret)
 990                         goto fd_error;
 991                 event_fd = 0;
 992                 if (event_param->u.syscall.enable) {
 993                         ret = lttng_syscall_filter_enable(channel,
 994                                 event_param->name[0] == '\0' ?
 995                                         NULL : event_param->name);
 996                         if (ret)
 997                                 goto fd_error;
 998
 999                 } else {
1000                         ret = lttng_syscall_filter_disable(channel,
1001                                 event_param->name[0] == '\0' ?
1002                                         NULL : event_param->name);
1003                         if (ret)
1004                                 goto fd_error;
1005                 }
1006                 break;
1007         }
1008         return event_fd;
1009
1010 event_error:
1011         fput(event_file);
1012 file_error:
1013         put_unused_fd(event_fd);
1014 fd_error:
1015         return ret;
1016 }
1017
1018 /**
1019  *      lttng_channel_ioctl - lttng syscall through ioctl
1020  *
1021  *      @file: the file
1022  *      @cmd: the command
1023  *      @arg: command arg
1024  *
1025  *      This ioctl implements lttng commands:
1026  *      LTTNG_KERNEL_STREAM
1027  *              Returns an event stream file descriptor or failure.
1028  *              (typically, one event stream records events from one CPU)
1029  *      LTTNG_KERNEL_EVENT
1030  *              Returns an event file descriptor or failure.
1031  *      LTTNG_KERNEL_CONTEXT
1032  *              Prepend a context field to each event in the channel
1033  *      LTTNG_KERNEL_ENABLE
1034  *              Enable recording for events in this channel (weak enable)
1035  *      LTTNG_KERNEL_DISABLE
1036  *              Disable recording for events in this channel (strong disable)
1037  *
1038  * Channel and event file descriptors also hold a reference on the session.
1039  */
1040 static
1041 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1042 {
1043         struct lttng_channel *channel = file->private_data;
1044
1045         switch (cmd) {
1046         case LTTNG_KERNEL_OLD_STREAM:
1047         case LTTNG_KERNEL_STREAM:
1048                 return lttng_abi_open_stream(file);
1049         case LTTNG_KERNEL_OLD_EVENT:
1050         {
1051                 struct lttng_kernel_event *uevent_param;
1052                 struct lttng_kernel_old_event *old_uevent_param;
1053                 int ret;
1054
1055                 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1056                                 GFP_KERNEL);
1057                 if (!uevent_param) {
1058                         ret = -ENOMEM;
1059                         goto old_event_end;
1060                 }
1061                 old_uevent_param = kmalloc(
1062                                 sizeof(struct lttng_kernel_old_event),
1063                                 GFP_KERNEL);
1064                 if (!old_uevent_param) {
1065                         ret = -ENOMEM;
1066                         goto old_event_error_free_param;
1067                 }
1068                 if (copy_from_user(old_uevent_param,
1069                                 (struct lttng_kernel_old_event __user *) arg,
1070                                 sizeof(struct lttng_kernel_old_event))) {
1071                         ret = -EFAULT;
1072                         goto old_event_error_free_old_param;
1073                 }
1074
1075                 memcpy(uevent_param->name, old_uevent_param->name,
1076                                 sizeof(uevent_param->name));
1077                 uevent_param->instrumentation =
1078                         old_uevent_param->instrumentation;
1079
1080                 switch (old_uevent_param->instrumentation) {
1081                 case LTTNG_KERNEL_KPROBE:
1082                         uevent_param->u.kprobe.addr =
1083                                 old_uevent_param->u.kprobe.addr;
1084                         uevent_param->u.kprobe.offset =
1085                                 old_uevent_param->u.kprobe.offset;
1086                         memcpy(uevent_param->u.kprobe.symbol_name,
1087                                 old_uevent_param->u.kprobe.symbol_name,
1088                                 sizeof(uevent_param->u.kprobe.symbol_name));
1089                         break;
1090                 case LTTNG_KERNEL_KRETPROBE:
1091                         uevent_param->u.kretprobe.addr =
1092                                 old_uevent_param->u.kretprobe.addr;
1093                         uevent_param->u.kretprobe.offset =
1094                                 old_uevent_param->u.kretprobe.offset;
1095                         memcpy(uevent_param->u.kretprobe.symbol_name,
1096                                 old_uevent_param->u.kretprobe.symbol_name,
1097                                 sizeof(uevent_param->u.kretprobe.symbol_name));
1098                         break;
1099                 case LTTNG_KERNEL_FUNCTION:
1100                         memcpy(uevent_param->u.ftrace.symbol_name,
1101                                         old_uevent_param->u.ftrace.symbol_name,
1102                                         sizeof(uevent_param->u.ftrace.symbol_name));
1103                         break;
1104                 default:
1105                         break;
1106                 }
1107                 ret = lttng_abi_create_event(file, uevent_param);
1108
1109 old_event_error_free_old_param:
1110                 kfree(old_uevent_param);
1111 old_event_error_free_param:
1112                 kfree(uevent_param);
1113 old_event_end:
1114                 return ret;
1115         }
1116         case LTTNG_KERNEL_EVENT:
1117         {
1118                 struct lttng_kernel_event uevent_param;
1119
1120                 if (copy_from_user(&uevent_param,
1121                                 (struct lttng_kernel_event __user *) arg,
1122                                 sizeof(uevent_param)))
1123                         return -EFAULT;
1124                 return lttng_abi_create_event(file, &uevent_param);
1125         }
1126         case LTTNG_KERNEL_OLD_CONTEXT:
1127         {
1128                 struct lttng_kernel_context *ucontext_param;
1129                 struct lttng_kernel_old_context *old_ucontext_param;
1130                 int ret;
1131
1132                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1133                                 GFP_KERNEL);
1134                 if (!ucontext_param) {
1135                         ret = -ENOMEM;
1136                         goto old_ctx_end;
1137                 }
1138                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1139                                 GFP_KERNEL);
1140                 if (!old_ucontext_param) {
1141                         ret = -ENOMEM;
1142                         goto old_ctx_error_free_param;
1143                 }
1144
1145                 if (copy_from_user(old_ucontext_param,
1146                                 (struct lttng_kernel_old_context __user *) arg,
1147                                 sizeof(struct lttng_kernel_old_context))) {
1148                         ret = -EFAULT;
1149                         goto old_ctx_error_free_old_param;
1150                 }
1151                 ucontext_param->ctx = old_ucontext_param->ctx;
1152                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1153                                 sizeof(ucontext_param->padding));
1154                 /* only type that uses the union */
1155                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1156                         ucontext_param->u.perf_counter.type =
1157                                 old_ucontext_param->u.perf_counter.type;
1158                         ucontext_param->u.perf_counter.config =
1159                                 old_ucontext_param->u.perf_counter.config;
1160                         memcpy(ucontext_param->u.perf_counter.name,
1161                                 old_ucontext_param->u.perf_counter.name,
1162                                 sizeof(ucontext_param->u.perf_counter.name));
1163                 }
1164
1165                 ret = lttng_abi_add_context(file,
1166                                 ucontext_param,
1167                                 &channel->ctx, channel->session);
1168
1169 old_ctx_error_free_old_param:
1170                 kfree(old_ucontext_param);
1171 old_ctx_error_free_param:
1172                 kfree(ucontext_param);
1173 old_ctx_end:
1174                 return ret;
1175         }
1176         case LTTNG_KERNEL_CONTEXT:
1177         {
1178                 struct lttng_kernel_context ucontext_param;
1179
1180                 if (copy_from_user(&ucontext_param,
1181                                 (struct lttng_kernel_context __user *) arg,
1182                                 sizeof(ucontext_param)))
1183                         return -EFAULT;
1184                 return lttng_abi_add_context(file,
1185                                 &ucontext_param,
1186                                 &channel->ctx, channel->session);
1187         }
1188         case LTTNG_KERNEL_OLD_ENABLE:
1189         case LTTNG_KERNEL_ENABLE:
1190                 return lttng_channel_enable(channel);
1191         case LTTNG_KERNEL_OLD_DISABLE:
1192         case LTTNG_KERNEL_DISABLE:
1193                 return lttng_channel_disable(channel);
1194         case LTTNG_KERNEL_SYSCALL_MASK:
1195                 return lttng_channel_syscall_mask(channel,
1196                         (struct lttng_kernel_syscall_mask __user *) arg);
1197         default:
1198                 return -ENOIOCTLCMD;
1199         }
1200
1201 }
1202
1203 /**
1204  *      lttng_metadata_ioctl - lttng syscall through ioctl
1205  *
1206  *      @file: the file
1207  *      @cmd: the command
1208  *      @arg: command arg
1209  *
1210  *      This ioctl implements lttng commands:
1211  *      LTTNG_KERNEL_STREAM
1212  *              Returns an event stream file descriptor or failure.
1213  *
1214  * Channel and event file descriptors also hold a reference on the session.
1215  */
1216 static
1217 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1218 {
1219         switch (cmd) {
1220         case LTTNG_KERNEL_OLD_STREAM:
1221         case LTTNG_KERNEL_STREAM:
1222                 return lttng_abi_open_metadata_stream(file);
1223         default:
1224                 return -ENOIOCTLCMD;
1225         }
1226 }
1227
1228 /**
1229  *      lttng_channel_poll - lttng stream addition/removal monitoring
1230  *
1231  *      @file: the file
1232  *      @wait: poll table
1233  */
1234 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1235 {
1236         struct lttng_channel *channel = file->private_data;
1237         unsigned int mask = 0;
1238
1239         if (file->f_mode & FMODE_READ) {
1240                 poll_wait_set_exclusive(wait);
1241                 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1242                           wait);
1243
1244                 if (channel->ops->is_disabled(channel->chan))
1245                         return POLLERR;
1246                 if (channel->ops->is_finalized(channel->chan))
1247                         return POLLHUP;
1248                 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1249                         return POLLIN | POLLRDNORM;
1250                 return 0;
1251         }
1252         return mask;
1253
1254 }
1255
1256 static
1257 int lttng_channel_release(struct inode *inode, struct file *file)
1258 {
1259         struct lttng_channel *channel = file->private_data;
1260
1261         if (channel)
1262                 fput(channel->session->file);
1263         return 0;
1264 }
1265
1266 static
1267 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1268 {
1269         struct lttng_channel *channel = file->private_data;
1270
1271         if (channel) {
1272                 lttng_metadata_channel_destroy(channel);
1273                 fput(channel->session->file);
1274         }
1275
1276         return 0;
1277 }
1278
1279 static const struct file_operations lttng_channel_fops = {
1280         .owner = THIS_MODULE,
1281         .release = lttng_channel_release,
1282         .poll = lttng_channel_poll,
1283         .unlocked_ioctl = lttng_channel_ioctl,
1284 #ifdef CONFIG_COMPAT
1285         .compat_ioctl = lttng_channel_ioctl,
1286 #endif
1287 };
1288
1289 static const struct file_operations lttng_metadata_fops = {
1290         .owner = THIS_MODULE,
1291         .release = lttng_metadata_channel_release,
1292         .unlocked_ioctl = lttng_metadata_ioctl,
1293 #ifdef CONFIG_COMPAT
1294         .compat_ioctl = lttng_metadata_ioctl,
1295 #endif
1296 };
1297
1298 /**
1299  *      lttng_event_ioctl - lttng syscall through ioctl
1300  *
1301  *      @file: the file
1302  *      @cmd: the command
1303  *      @arg: command arg
1304  *
1305  *      This ioctl implements lttng commands:
1306  *      LTTNG_KERNEL_CONTEXT
1307  *              Prepend a context field to each record of this event
1308  *      LTTNG_KERNEL_ENABLE
1309  *              Enable recording for this event (weak enable)
1310  *      LTTNG_KERNEL_DISABLE
1311  *              Disable recording for this event (strong disable)
1312  */
1313 static
1314 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1315 {
1316         struct lttng_event *event = file->private_data;
1317
1318         switch (cmd) {
1319         case LTTNG_KERNEL_OLD_CONTEXT:
1320         {
1321                 struct lttng_kernel_context *ucontext_param;
1322                 struct lttng_kernel_old_context *old_ucontext_param;
1323                 int ret;
1324
1325                 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1326                                 GFP_KERNEL);
1327                 if (!ucontext_param) {
1328                         ret = -ENOMEM;
1329                         goto old_ctx_end;
1330                 }
1331                 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1332                                 GFP_KERNEL);
1333                 if (!old_ucontext_param) {
1334                         ret = -ENOMEM;
1335                         goto old_ctx_error_free_param;
1336                 }
1337
1338                 if (copy_from_user(old_ucontext_param,
1339                                         (struct lttng_kernel_old_context __user *) arg,
1340                                         sizeof(struct lttng_kernel_old_context))) {
1341                         ret = -EFAULT;
1342                         goto old_ctx_error_free_old_param;
1343                 }
1344                 ucontext_param->ctx = old_ucontext_param->ctx;
1345                 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1346                                 sizeof(ucontext_param->padding));
1347                 /* only type that uses the union */
1348                 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1349                         ucontext_param->u.perf_counter.type =
1350                                 old_ucontext_param->u.perf_counter.type;
1351                         ucontext_param->u.perf_counter.config =
1352                                 old_ucontext_param->u.perf_counter.config;
1353                         memcpy(ucontext_param->u.perf_counter.name,
1354                                         old_ucontext_param->u.perf_counter.name,
1355                                         sizeof(ucontext_param->u.perf_counter.name));
1356                 }
1357
1358                 ret = lttng_abi_add_context(file,
1359                                 ucontext_param,
1360                                 &event->ctx, event->chan->session);
1361
1362 old_ctx_error_free_old_param:
1363                 kfree(old_ucontext_param);
1364 old_ctx_error_free_param:
1365                 kfree(ucontext_param);
1366 old_ctx_end:
1367                 return ret;
1368         }
1369         case LTTNG_KERNEL_CONTEXT:
1370         {
1371                 struct lttng_kernel_context ucontext_param;
1372
1373                 if (copy_from_user(&ucontext_param,
1374                                         (struct lttng_kernel_context __user *) arg,
1375                                         sizeof(ucontext_param)))
1376                         return -EFAULT;
1377                 return lttng_abi_add_context(file,
1378                                 &ucontext_param,
1379                                 &event->ctx, event->chan->session);
1380         }
1381         case LTTNG_KERNEL_OLD_ENABLE:
1382         case LTTNG_KERNEL_ENABLE:
1383                 return lttng_event_enable(event);
1384         case LTTNG_KERNEL_OLD_DISABLE:
1385         case LTTNG_KERNEL_DISABLE:
1386                 return lttng_event_disable(event);
1387         default:
1388                 return -ENOIOCTLCMD;
1389         }
1390 }
1391
1392 static
1393 int lttng_event_release(struct inode *inode, struct file *file)
1394 {
1395         struct lttng_event *event = file->private_data;
1396
1397         if (event)
1398                 fput(event->chan->file);
1399         return 0;
1400 }
1401
1402 /* TODO: filter control ioctl */
1403 static const struct file_operations lttng_event_fops = {
1404         .owner = THIS_MODULE,
1405         .release = lttng_event_release,
1406         .unlocked_ioctl = lttng_event_ioctl,
1407 #ifdef CONFIG_COMPAT
1408         .compat_ioctl = lttng_event_ioctl,
1409 #endif
1410 };
1411
1412 static int put_u64(uint64_t val, unsigned long arg)
1413 {
1414         return put_user(val, (uint64_t __user *) arg);
1415 }
1416
1417 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1418                 unsigned int cmd, unsigned long arg)
1419 {
1420         struct lib_ring_buffer *buf = filp->private_data;
1421         struct channel *chan = buf->backend.chan;
1422         const struct lib_ring_buffer_config *config = &chan->backend.config;
1423         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1424         int ret;
1425
1426         if (atomic_read(&chan->record_disabled))
1427                 return -EIO;
1428
1429         switch (cmd) {
1430         case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1431         {
1432                 uint64_t ts;
1433
1434                 ret = ops->timestamp_begin(config, buf, &ts);
1435                 if (ret < 0)
1436                         goto error;
1437                 return put_u64(ts, arg);
1438         }
1439         case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1440         {
1441                 uint64_t ts;
1442
1443                 ret = ops->timestamp_end(config, buf, &ts);
1444                 if (ret < 0)
1445                         goto error;
1446                 return put_u64(ts, arg);
1447         }
1448         case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1449         {
1450                 uint64_t ed;
1451
1452                 ret = ops->events_discarded(config, buf, &ed);
1453                 if (ret < 0)
1454                         goto error;
1455                 return put_u64(ed, arg);
1456         }
1457         case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1458         {
1459                 uint64_t cs;
1460
1461                 ret = ops->content_size(config, buf, &cs);
1462                 if (ret < 0)
1463                         goto error;
1464                 return put_u64(cs, arg);
1465         }
1466         case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1467         {
1468                 uint64_t ps;
1469
1470                 ret = ops->packet_size(config, buf, &ps);
1471                 if (ret < 0)
1472                         goto error;
1473                 return put_u64(ps, arg);
1474         }
1475         case LTTNG_RING_BUFFER_GET_STREAM_ID:
1476         {
1477                 uint64_t si;
1478
1479                 ret = ops->stream_id(config, buf, &si);
1480                 if (ret < 0)
1481                         goto error;
1482                 return put_u64(si, arg);
1483         }
1484         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1485         {
1486                 uint64_t ts;
1487
1488                 ret = ops->current_timestamp(config, buf, &ts);
1489                 if (ret < 0)
1490                         goto error;
1491                 return put_u64(ts, arg);
1492         }
1493         default:
1494                 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1495                                 cmd, arg);
1496         }
1497
1498 error:
1499         return -ENOSYS;
1500 }
1501
1502 #ifdef CONFIG_COMPAT
1503 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1504                 unsigned int cmd, unsigned long arg)
1505 {
1506         struct lib_ring_buffer *buf = filp->private_data;
1507         struct channel *chan = buf->backend.chan;
1508         const struct lib_ring_buffer_config *config = &chan->backend.config;
1509         const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1510         int ret;
1511
1512         if (atomic_read(&chan->record_disabled))
1513                 return -EIO;
1514
1515         switch (cmd) {
1516         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1517         {
1518                 uint64_t ts;
1519
1520                 ret = ops->timestamp_begin(config, buf, &ts);
1521                 if (ret < 0)
1522                         goto error;
1523                 return put_u64(ts, arg);
1524         }
1525         case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1526         {
1527                 uint64_t ts;
1528
1529                 ret = ops->timestamp_end(config, buf, &ts);
1530                 if (ret < 0)
1531                         goto error;
1532                 return put_u64(ts, arg);
1533         }
1534         case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1535         {
1536                 uint64_t ed;
1537
1538                 ret = ops->events_discarded(config, buf, &ed);
1539                 if (ret < 0)
1540                         goto error;
1541                 return put_u64(ed, arg);
1542         }
1543         case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1544         {
1545                 uint64_t cs;
1546
1547                 ret = ops->content_size(config, buf, &cs);
1548                 if (ret < 0)
1549                         goto error;
1550                 return put_u64(cs, arg);
1551         }
1552         case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1553         {
1554                 uint64_t ps;
1555
1556                 ret = ops->packet_size(config, buf, &ps);
1557                 if (ret < 0)
1558                         goto error;
1559                 return put_u64(ps, arg);
1560         }
1561         case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1562         {
1563                 uint64_t si;
1564
1565                 ret = ops->stream_id(config, buf, &si);
1566                 if (ret < 0)
1567                         goto error;
1568                 return put_u64(si, arg);
1569         }
1570         case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1571         {
1572                 uint64_t ts;
1573
1574                 ret = ops->current_timestamp(config, buf, &ts);
1575                 if (ret < 0)
1576                         goto error;
1577                 return put_u64(ts, arg);
1578         }
1579         default:
1580                 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1581                                 cmd, arg);
1582         }
1583
1584 error:
1585         return -ENOSYS;
1586 }
1587 #endif /* CONFIG_COMPAT */
1588
1589 static void lttng_stream_override_ring_buffer_fops(void)
1590 {
1591         lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1592         lttng_stream_ring_buffer_file_operations.open =
1593                 lib_ring_buffer_file_operations.open;
1594         lttng_stream_ring_buffer_file_operations.release =
1595                 lib_ring_buffer_file_operations.release;
1596         lttng_stream_ring_buffer_file_operations.poll =
1597                 lib_ring_buffer_file_operations.poll;
1598         lttng_stream_ring_buffer_file_operations.splice_read =
1599                 lib_ring_buffer_file_operations.splice_read;
1600         lttng_stream_ring_buffer_file_operations.mmap =
1601                 lib_ring_buffer_file_operations.mmap;
1602         lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1603                 lttng_stream_ring_buffer_ioctl;
1604         lttng_stream_ring_buffer_file_operations.llseek =
1605                 lib_ring_buffer_file_operations.llseek;
1606 #ifdef CONFIG_COMPAT
1607         lttng_stream_ring_buffer_file_operations.compat_ioctl =
1608                 lttng_stream_ring_buffer_compat_ioctl;
1609 #endif
1610 }
1611
1612 int __init lttng_abi_init(void)
1613 {
1614         int ret = 0;
1615
1616         wrapper_vmalloc_sync_all();
1617         lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1618                                         &lttng_fops, NULL);
1619
1620         if (!lttng_proc_dentry) {
1621                 printk(KERN_ERR "Error creating LTTng control file\n");
1622                 ret = -ENOMEM;
1623                 goto error;
1624         }
1625         lttng_stream_override_ring_buffer_fops();
1626
1627 error:
1628         return ret;
1629 }
1630
1631 /* No __exit annotation because used by init error path too. */
1632 void lttng_abi_exit(void)
1633 {
1634         if (lttng_proc_dentry)
1635                 remove_proc_entry("lttng", NULL);
1636 }