drivers/input/evdev.c

   1 /*
   2  * Event char devices, giving access to raw input device events.
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  */
  10
  11 #define EVDEV_MINOR_BASE        64
  12 #define EVDEV_MINORS            32
  13 #define EVDEV_BUFFER_SIZE       64
  14
  15 #include <linux/poll.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/module.h>
  19 #include <linux/init.h>
  20 #include <linux/input.h>
  21 #include <linux/major.h>
  22 #include <linux/device.h>
  23 #include "input-compat.h"
  24
  25 struct evdev {
  26         int exist;
  27         int open;
  28         int minor;
  29         struct input_handle handle;
  30         wait_queue_head_t wait;
  31         struct evdev_client *grab;
  32         struct list_head client_list;
  33         spinlock_t client_lock; /* protects client_list */
  34         struct mutex mutex;
  35         struct device dev;
  36 };
  37
  38 struct evdev_client {
  39         struct input_event buffer[EVDEV_BUFFER_SIZE];
  40         int head;
  41         int tail;
  42         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  43         struct fasync_struct *fasync;
  44         struct evdev *evdev;
  45         struct list_head node;
  46 };
  47
  48 static struct evdev *evdev_table[EVDEV_MINORS];
  49 static DEFINE_MUTEX(evdev_table_mutex);
  50
  51 static void evdev_pass_event(struct evdev_client *client,
  52                              struct input_event *event)
  53 {
  54         /*
  55          * Interrupts are disabled, just acquire the lock
  56          */
  57         spin_lock(&client->buffer_lock);
  58         client->buffer[client->head++] = *event;
  59         client->head &= EVDEV_BUFFER_SIZE - 1;
  60         spin_unlock(&client->buffer_lock);
  61
  62         if (event->type == EV_SYN)
  63                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
  64 }
  65
  66 /*
  67  * Pass incoming event to all connected clients.
  68  */
  69 static void evdev_event(struct input_handle *handle,
  70                         unsigned int type, unsigned int code, int value)
  71 {
  72         struct evdev *evdev = handle->private;
  73         struct evdev_client *client;
  74         struct input_event event;
  75
  76         do_gettimeofday(&event.time);
  77         event.type = type;
  78         event.code = code;
  79         event.value = value;
  80
  81         rcu_read_lock();
  82
  83         client = rcu_dereference(evdev->grab);
  84         if (client)
  85                 evdev_pass_event(client, &event);
  86         else
  87                 list_for_each_entry_rcu(client, &evdev->client_list, node)
  88                         evdev_pass_event(client, &event);
  89
  90         rcu_read_unlock();
  91
  92         wake_up_interruptible(&evdev->wait);
  93 }
  94
  95 static int evdev_fasync(int fd, struct file *file, int on)
  96 {
  97         struct evdev_client *client = file->private_data;
  98
  99         return fasync_helper(fd, file, on, &client->fasync);
 100 }
 101
 102 static int evdev_flush(struct file *file, fl_owner_t id)
 103 {
 104         struct evdev_client *client = file->private_data;
 105         struct evdev *evdev = client->evdev;
 106         int retval;
 107
 108         retval = mutex_lock_interruptible(&evdev->mutex);
 109         if (retval)
 110                 return retval;
 111
 112         if (!evdev->exist)
 113                 retval = -ENODEV;
 114         else
 115                 retval = input_flush_device(&evdev->handle, file);
 116
 117         mutex_unlock(&evdev->mutex);
 118         return retval;
 119 }
 120
 121 static void evdev_free(struct device *dev)
 122 {
 123         struct evdev *evdev = container_of(dev, struct evdev, dev);
 124
 125         input_put_device(evdev->handle.dev);
 126         kfree(evdev);
 127 }
 128
 129 /*
 130  * Grabs an event device (along with underlying input device).
 131  * This function is called with evdev->mutex taken.
 132  */
 133 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 134 {
 135         int error;
 136
 137         if (evdev->grab)
 138                 return -EBUSY;
 139
 140         error = input_grab_device(&evdev->handle);
 141         if (error)
 142                 return error;
 143
 144         rcu_assign_pointer(evdev->grab, client);
 145         synchronize_rcu();
 146
 147         return 0;
 148 }
 149
 150 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 151 {
 152         if (evdev->grab != client)
 153                 return  -EINVAL;
 154
 155         rcu_assign_pointer(evdev->grab, NULL);
 156         synchronize_rcu();
 157         input_release_device(&evdev->handle);
 158
 159         return 0;
 160 }
 161
 162 static void evdev_attach_client(struct evdev *evdev,
 163                                 struct evdev_client *client)
 164 {
 165         spin_lock(&evdev->client_lock);
 166         list_add_tail_rcu(&client->node, &evdev->client_list);
 167         spin_unlock(&evdev->client_lock);
 168         synchronize_rcu();
 169 }
 170
 171 static void evdev_detach_client(struct evdev *evdev,
 172                                 struct evdev_client *client)
 173 {
 174         spin_lock(&evdev->client_lock);
 175         list_del_rcu(&client->node);
 176         spin_unlock(&evdev->client_lock);
 177         synchronize_rcu();
 178 }
 179
 180 static int evdev_open_device(struct evdev *evdev)
 181 {
 182         int retval;
 183
 184         retval = mutex_lock_interruptible(&evdev->mutex);
 185         if (retval)
 186                 return retval;
 187
 188         if (!evdev->exist)
 189                 retval = -ENODEV;
 190         else if (!evdev->open++) {
 191                 retval = input_open_device(&evdev->handle);
 192                 if (retval)
 193                         evdev->open--;
 194         }
 195
 196         mutex_unlock(&evdev->mutex);
 197         return retval;
 198 }
 199
 200 static void evdev_close_device(struct evdev *evdev)
 201 {
 202         mutex_lock(&evdev->mutex);
 203
 204         if (evdev->exist && !--evdev->open)
 205                 input_close_device(&evdev->handle);
 206
 207         mutex_unlock(&evdev->mutex);
 208 }
 209
 210 /*
 211  * Wake up users waiting for IO so they can disconnect from
 212  * dead device.
 213  */
 214 static void evdev_hangup(struct evdev *evdev)
 215 {
 216         struct evdev_client *client;
 217
 218         spin_lock(&evdev->client_lock);
 219         list_for_each_entry(client, &evdev->client_list, node)
 220                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 221         spin_unlock(&evdev->client_lock);
 222
 223         wake_up_interruptible(&evdev->wait);
 224 }
 225
 226 static int evdev_release(struct inode *inode, struct file *file)
 227 {
 228         struct evdev_client *client = file->private_data;
 229         struct evdev *evdev = client->evdev;
 230
 231         mutex_lock(&evdev->mutex);
 232         if (evdev->grab == client)
 233                 evdev_ungrab(evdev, client);
 234         mutex_unlock(&evdev->mutex);
 235
 236         evdev_detach_client(evdev, client);
 237         kfree(client);
 238
 239         evdev_close_device(evdev);
 240         put_device(&evdev->dev);
 241
 242         return 0;
 243 }
 244
 245 static int evdev_open(struct inode *inode, struct file *file)
 246 {
 247         struct evdev *evdev;
 248         struct evdev_client *client;
 249         int i = iminor(inode) - EVDEV_MINOR_BASE;
 250         int error;
 251
 252         if (i >= EVDEV_MINORS)
 253                 return -ENODEV;
 254
 255         error = mutex_lock_interruptible(&evdev_table_mutex);
 256         if (error)
 257                 return error;
 258         evdev = evdev_table[i];
 259         if (evdev)
 260                 get_device(&evdev->dev);
 261         mutex_unlock(&evdev_table_mutex);
 262
 263         if (!evdev)
 264                 return -ENODEV;
 265
 266         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
 267         if (!client) {
 268                 error = -ENOMEM;
 269                 goto err_put_evdev;
 270         }
 271
 272         spin_lock_init(&client->buffer_lock);
 273         client->evdev = evdev;
 274         evdev_attach_client(evdev, client);
 275
 276         error = evdev_open_device(evdev);
 277         if (error)
 278                 goto err_free_client;
 279
 280         file->private_data = client;
 281         return 0;
 282
 283  err_free_client:
 284         evdev_detach_client(evdev, client);
 285         kfree(client);
 286  err_put_evdev:
 287         put_device(&evdev->dev);
 288         return error;
 289 }
 290
 291 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 292                            size_t count, loff_t *ppos)
 293 {
 294         struct evdev_client *client = file->private_data;
 295         struct evdev *evdev = client->evdev;
 296         struct input_event event;
 297         int retval;
 298
 299         retval = mutex_lock_interruptible(&evdev->mutex);
 300         if (retval)
 301                 return retval;
 302
 303         if (!evdev->exist) {
 304                 retval = -ENODEV;
 305                 goto out;
 306         }
 307
 308         while (retval < count) {
 309
 310                 if (input_event_from_user(buffer + retval, &event)) {
 311                         retval = -EFAULT;
 312                         goto out;
 313                 }
 314
 315                 input_inject_event(&evdev->handle,
 316                                    event.type, event.code, event.value);
 317                 retval += input_event_size();
 318         }
 319
 320  out:
 321         mutex_unlock(&evdev->mutex);
 322         return retval;
 323 }
 324
 325 static int evdev_fetch_next_event(struct evdev_client *client,
 326                                   struct input_event *event)
 327 {
 328         int have_event;
 329
 330         spin_lock_irq(&client->buffer_lock);
 331
 332         have_event = client->head != client->tail;
 333         if (have_event) {
 334                 *event = client->buffer[client->tail++];
 335                 client->tail &= EVDEV_BUFFER_SIZE - 1;
 336         }
 337
 338         spin_unlock_irq(&client->buffer_lock);
 339
 340         return have_event;
 341 }
 342
 343 static ssize_t evdev_read(struct file *file, char __user *buffer,
 344                           size_t count, loff_t *ppos)
 345 {
 346         struct evdev_client *client = file->private_data;
 347         struct evdev *evdev = client->evdev;
 348         struct input_event event;
 349         int retval;
 350
 351         if (count < input_event_size())
 352                 return -EINVAL;
 353
 354         if (client->head == client->tail && evdev->exist &&
 355             (file->f_flags & O_NONBLOCK))
 356                 return -EAGAIN;
 357
 358         retval = wait_event_interruptible(evdev->wait,
 359                 client->head != client->tail || !evdev->exist);
 360         if (retval)
 361                 return retval;
 362
 363         if (!evdev->exist)
 364                 return -ENODEV;
 365
 366         while (retval + input_event_size() <= count &&
 367                evdev_fetch_next_event(client, &event)) {
 368
 369                 if (input_event_to_user(buffer + retval, &event))
 370                         return -EFAULT;
 371
 372                 retval += input_event_size();
 373         }
 374
 375         return retval;
 376 }
 377
 378 /* No kernel lock - fine */
 379 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 380 {
 381         struct evdev_client *client = file->private_data;
 382         struct evdev *evdev = client->evdev;
 383
 384         poll_wait(file, &evdev->wait, wait);
 385         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 386                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
 387 }
 388
 389 #ifdef CONFIG_COMPAT
 390
 391 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 392 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 393
 394 #ifdef __BIG_ENDIAN
 395 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 396                         unsigned int maxlen, void __user *p, int compat)
 397 {
 398         int len, i;
 399
 400         if (compat) {
 401                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 402                 if (len > maxlen)
 403                         len = maxlen;
 404
 405                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 406                         if (copy_to_user((compat_long_t __user *) p + i,
 407                                          (compat_long_t *) bits +
 408                                                 i + 1 - ((i % 2) << 1),
 409                                          sizeof(compat_long_t)))
 410                                 return -EFAULT;
 411         } else {
 412                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 413                 if (len > maxlen)
 414                         len = maxlen;
 415
 416                 if (copy_to_user(p, bits, len))
 417                         return -EFAULT;
 418         }
 419
 420         return len;
 421 }
 422 #else
 423 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 424                         unsigned int maxlen, void __user *p, int compat)
 425 {
 426         int len = compat ?
 427                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 428                         BITS_TO_LONGS(maxbit) * sizeof(long);
 429
 430         if (len > maxlen)
 431                 len = maxlen;
 432
 433         return copy_to_user(p, bits, len) ? -EFAULT : len;
 434 }
 435 #endif /* __BIG_ENDIAN */
 436
 437 #else
 438
 439 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 440                         unsigned int maxlen, void __user *p, int compat)
 441 {
 442         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 443
 444         if (len > maxlen)
 445                 len = maxlen;
 446
 447         return copy_to_user(p, bits, len) ? -EFAULT : len;
 448 }
 449
 450 #endif /* CONFIG_COMPAT */
 451
 452 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 453 {
 454         int len;
 455
 456         if (!str)
 457                 return -ENOENT;
 458
 459         len = strlen(str) + 1;
 460         if (len > maxlen)
 461                 len = maxlen;
 462
 463         return copy_to_user(p, str, len) ? -EFAULT : len;
 464 }
 465
 466 #define OLD_KEY_MAX     0x1ff
 467 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
 468 {
 469         static unsigned long keymax_warn_time;
 470         unsigned long *bits;
 471         int len;
 472
 473         switch (_IOC_NR(cmd) & EV_MAX) {
 474
 475         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 476         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 477         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 478         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 479         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 480         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 481         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 482         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 483         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 484         default: return -EINVAL;
 485         }
 486
 487         /*
 488          * Work around bugs in userspace programs that like to do
 489          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 490          * should be in bytes, not in bits.
 491          */
 492         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
 493                 len = OLD_KEY_MAX;
 494                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 495                         printk(KERN_WARNING
 496                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
 497                                 "limiting output to %zu bytes. See "
 498                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 499                                 OLD_KEY_MAX,
 500                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 501         }
 502
 503         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 504 }
 505 #undef OLD_KEY_MAX
 506
 507 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 508                            void __user *p, int compat_mode)
 509 {
 510         struct evdev_client *client = file->private_data;
 511         struct evdev *evdev = client->evdev;
 512         struct input_dev *dev = evdev->handle.dev;
 513         struct input_absinfo abs;
 514         struct ff_effect effect;
 515         int __user *ip = (int __user *)p;
 516         int i, t, u, v;
 517         int error;
 518
 519         switch (cmd) {
 520
 521         case EVIOCGVERSION:
 522                 return put_user(EV_VERSION, ip);
 523
 524         case EVIOCGID:
 525                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 526                         return -EFAULT;
 527                 return 0;
 528
 529         case EVIOCGREP:
 530                 if (!test_bit(EV_REP, dev->evbit))
 531                         return -ENOSYS;
 532                 if (put_user(dev->rep[REP_DELAY], ip))
 533                         return -EFAULT;
 534                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 535                         return -EFAULT;
 536                 return 0;
 537
 538         case EVIOCSREP:
 539                 if (!test_bit(EV_REP, dev->evbit))
 540                         return -ENOSYS;
 541                 if (get_user(u, ip))
 542                         return -EFAULT;
 543                 if (get_user(v, ip + 1))
 544                         return -EFAULT;
 545
 546                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 547                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 548
 549                 return 0;
 550
 551         case EVIOCGKEYCODE:
 552                 if (get_user(t, ip))
 553                         return -EFAULT;
 554
 555                 error = input_get_keycode(dev, t, &v);
 556                 if (error)
 557                         return error;
 558
 559                 if (put_user(v, ip + 1))
 560                         return -EFAULT;
 561
 562                 return 0;
 563
 564         case EVIOCSKEYCODE:
 565                 if (get_user(t, ip) || get_user(v, ip + 1))
 566                         return -EFAULT;
 567
 568                 return input_set_keycode(dev, t, v);
 569
 570         case EVIOCRMFF:
 571                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 572
 573         case EVIOCGEFFECTS:
 574                 i = test_bit(EV_FF, dev->evbit) ?
 575                                 dev->ff->max_effects : 0;
 576                 if (put_user(i, ip))
 577                         return -EFAULT;
 578                 return 0;
 579
 580         case EVIOCGRAB:
 581                 if (p)
 582                         return evdev_grab(evdev, client);
 583                 else
 584                         return evdev_ungrab(evdev, client);
 585
 586         default:
 587
 588                 if (_IOC_TYPE(cmd) != 'E')
 589                         return -EINVAL;
 590
 591                 if (_IOC_DIR(cmd) == _IOC_READ) {
 592
 593                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 594                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
 595
 596                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 597                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 598                                                     p, compat_mode);
 599
 600                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 601                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 602                                                     p, compat_mode);
 603
 604                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 605                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 606                                                     p, compat_mode);
 607
 608                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 609                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 610                                                     p, compat_mode);
 611
 612                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 613                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
 614
 615                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 616                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
 617
 618                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 619                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
 620
 621                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 622
 623                                 t = _IOC_NR(cmd) & ABS_MAX;
 624
 625                                 abs.value = dev->abs[t];
 626                                 abs.minimum = dev->absmin[t];
 627                                 abs.maximum = dev->absmax[t];
 628                                 abs.fuzz = dev->absfuzz[t];
 629                                 abs.flat = dev->absflat[t];
 630                                 abs.resolution = dev->absres[t];
 631
 632                                 if (copy_to_user(p, &abs, min_t(size_t,
 633                                                                 _IOC_SIZE(cmd),
 634                                                                 sizeof(struct input_absinfo))))
 635                                         return -EFAULT;
 636
 637                                 return 0;
 638                         }
 639
 640                 }
 641
 642                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
 643
 644                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
 645
 646                                 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
 647                                         return -EFAULT;
 648
 649                                 error = input_ff_upload(dev, &effect, file);
 650
 651                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 652                                         return -EFAULT;
 653
 654                                 return error;
 655                         }
 656
 657                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 658
 659                                 t = _IOC_NR(cmd) & ABS_MAX;
 660
 661                                 if (copy_from_user(&abs, p, min_t(size_t,
 662                                                                   _IOC_SIZE(cmd),
 663                                                                   sizeof(struct input_absinfo))))
 664                                         return -EFAULT;
 665
 666                                 /*
 667                                  * Take event lock to ensure that we are not
 668                                  * changing device parameters in the middle
 669                                  * of event.
 670                                  */
 671                                 spin_lock_irq(&dev->event_lock);
 672
 673                                 dev->abs[t] = abs.value;
 674                                 dev->absmin[t] = abs.minimum;
 675                                 dev->absmax[t] = abs.maximum;
 676                                 dev->absfuzz[t] = abs.fuzz;
 677                                 dev->absflat[t] = abs.flat;
 678                                 dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
 679                                                         0 : abs.resolution;
 680
 681                                 spin_unlock_irq(&dev->event_lock);
 682
 683                                 return 0;
 684                         }
 685                 }
 686         }
 687         return -EINVAL;
 688 }
 689
 690 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 691                                 void __user *p, int compat_mode)
 692 {
 693         struct evdev_client *client = file->private_data;
 694         struct evdev *evdev = client->evdev;
 695         int retval;
 696
 697         retval = mutex_lock_interruptible(&evdev->mutex);
 698         if (retval)
 699                 return retval;
 700
 701         if (!evdev->exist) {
 702                 retval = -ENODEV;
 703                 goto out;
 704         }
 705
 706         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 707
 708  out:
 709         mutex_unlock(&evdev->mutex);
 710         return retval;
 711 }
 712
 713 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 714 {
 715         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 716 }
 717
 718 #ifdef CONFIG_COMPAT
 719 static long evdev_ioctl_compat(struct file *file,
 720                                 unsigned int cmd, unsigned long arg)
 721 {
 722         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 723 }
 724 #endif
 725
 726 static const struct file_operations evdev_fops = {
 727         .owner          = THIS_MODULE,
 728         .read           = evdev_read,
 729         .write          = evdev_write,
 730         .poll           = evdev_poll,
 731         .open           = evdev_open,
 732         .release        = evdev_release,
 733         .unlocked_ioctl = evdev_ioctl,
 734 #ifdef CONFIG_COMPAT
 735         .compat_ioctl   = evdev_ioctl_compat,
 736 #endif
 737         .fasync         = evdev_fasync,
 738         .flush          = evdev_flush
 739 };
 740
 741 static int evdev_install_chrdev(struct evdev *evdev)
 742 {
 743         /*
 744          * No need to do any locking here as calls to connect and
 745          * disconnect are serialized by the input core
 746          */
 747         evdev_table[evdev->minor] = evdev;
 748         return 0;
 749 }
 750
 751 static void evdev_remove_chrdev(struct evdev *evdev)
 752 {
 753         /*
 754          * Lock evdev table to prevent race with evdev_open()
 755          */
 756         mutex_lock(&evdev_table_mutex);
 757         evdev_table[evdev->minor] = NULL;
 758         mutex_unlock(&evdev_table_mutex);
 759 }
 760
 761 /*
 762  * Mark device non-existent. This disables writes, ioctls and
 763  * prevents new users from opening the device. Already posted
 764  * blocking reads will stay, however new ones will fail.
 765  */
 766 static void evdev_mark_dead(struct evdev *evdev)
 767 {
 768         mutex_lock(&evdev->mutex);
 769         evdev->exist = 0;
 770         mutex_unlock(&evdev->mutex);
 771 }
 772
 773 static void evdev_cleanup(struct evdev *evdev)
 774 {
 775         struct input_handle *handle = &evdev->handle;
 776
 777         evdev_mark_dead(evdev);
 778         evdev_hangup(evdev);
 779         evdev_remove_chrdev(evdev);
 780
 781         /* evdev is marked dead so no one else accesses evdev->open */
 782         if (evdev->open) {
 783                 input_flush_device(handle, NULL);
 784                 input_close_device(handle);
 785         }
 786 }
 787
 788 /*
 789  * Create new evdev device. Note that input core serializes calls
 790  * to connect and disconnect so we don't need to lock evdev_table here.
 791  */
 792 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 793                          const struct input_device_id *id)
 794 {
 795         struct evdev *evdev;
 796         int minor;
 797         int error;
 798
 799         for (minor = 0; minor < EVDEV_MINORS; minor++)
 800                 if (!evdev_table[minor])
 801                         break;
 802
 803         if (minor == EVDEV_MINORS) {
 804                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 805                 return -ENFILE;
 806         }
 807
 808         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 809         if (!evdev)
 810                 return -ENOMEM;
 811
 812         INIT_LIST_HEAD(&evdev->client_list);
 813         spin_lock_init(&evdev->client_lock);
 814         mutex_init(&evdev->mutex);
 815         init_waitqueue_head(&evdev->wait);
 816
 817         dev_set_name(&evdev->dev, "event%d", minor);
 818         evdev->exist = 1;
 819         evdev->minor = minor;
 820
 821         evdev->handle.dev = input_get_device(dev);
 822         evdev->handle.name = dev_name(&evdev->dev);
 823         evdev->handle.handler = handler;
 824         evdev->handle.private = evdev;
 825
 826         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 827         evdev->dev.class = &input_class;
 828         evdev->dev.parent = &dev->dev;
 829         evdev->dev.release = evdev_free;
 830         device_initialize(&evdev->dev);
 831
 832         error = input_register_handle(&evdev->handle);
 833         if (error)
 834                 goto err_free_evdev;
 835
 836         error = evdev_install_chrdev(evdev);
 837         if (error)
 838                 goto err_unregister_handle;
 839
 840         error = device_add(&evdev->dev);
 841         if (error)
 842                 goto err_cleanup_evdev;
 843
 844         return 0;
 845
 846  err_cleanup_evdev:
 847         evdev_cleanup(evdev);
 848  err_unregister_handle:
 849         input_unregister_handle(&evdev->handle);
 850  err_free_evdev:
 851         put_device(&evdev->dev);
 852         return error;
 853 }
 854
 855 static void evdev_disconnect(struct input_handle *handle)
 856 {
 857         struct evdev *evdev = handle->private;
 858
 859         device_del(&evdev->dev);
 860         evdev_cleanup(evdev);
 861         input_unregister_handle(handle);
 862         put_device(&evdev->dev);
 863 }
 864
 865 static const struct input_device_id evdev_ids[] = {
 866         { .driver_info = 1 },   /* Matches all devices */
 867         { },                    /* Terminating zero entry */
 868 };
 869
 870 MODULE_DEVICE_TABLE(input, evdev_ids);
 871
 872 static struct input_handler evdev_handler = {
 873         .event          = evdev_event,
 874         .connect        = evdev_connect,
 875         .disconnect     = evdev_disconnect,
 876         .fops           = &evdev_fops,
 877         .minor          = EVDEV_MINOR_BASE,
 878         .name           = "evdev",
 879         .id_table       = evdev_ids,
 880 };
 881
 882 static int __init evdev_init(void)
 883 {
 884         return input_register_handler(&evdev_handler);
 885 }
 886
 887 static void __exit evdev_exit(void)
 888 {
 889         input_unregister_handler(&evdev_handler);
 890 }
 891
 892 module_init(evdev_init);
 893 module_exit(evdev_exit);
 894
 895 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 896 MODULE_DESCRIPTION("Input driver event char devices");
 897 MODULE_LICENSE("GPL");