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 <linux/wakelock.h>
  24 #include "input-compat.h"
  25
  26 struct evdev {
  27         int exist;
  28         int open;
  29         int minor;
  30         struct input_handle handle;
  31         wait_queue_head_t wait;
  32         struct evdev_client *grab;
  33         struct list_head client_list;
  34         spinlock_t client_lock; /* protects client_list */
  35         struct mutex mutex;
  36         struct device dev;
  37 };
  38
  39 struct evdev_client {
  40         struct input_event buffer[EVDEV_BUFFER_SIZE];
  41         int head;
  42         int tail;
  43         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  44         struct fasync_struct *fasync;
  45         struct evdev *evdev;
  46         struct list_head node;
  47         struct wake_lock wake_lock;
  48         char name[28];
  49 };
  50
  51 static struct evdev *evdev_table[EVDEV_MINORS];
  52 static DEFINE_MUTEX(evdev_table_mutex);
  53
  54 static void evdev_pass_event(struct evdev_client *client,
  55                              struct input_event *event)
  56 {
  57         /*
  58          * Interrupts are disabled, just acquire the lock
  59          */
  60         spin_lock(&client->buffer_lock);
  61         wake_lock_timeout(&client->wake_lock, 5 * HZ);
  62         client->buffer[client->head++] = *event;
  63         client->head &= EVDEV_BUFFER_SIZE - 1;
  64         spin_unlock(&client->buffer_lock);
  65
  66         kill_fasync(&client->fasync, SIGIO, POLL_IN);
  67 }
  68
  69 /*
  70  * Pass incoming event to all connected clients.
  71  */
  72 static void evdev_event(struct input_handle *handle,
  73                         unsigned int type, unsigned int code, int value)
  74 {
  75         struct evdev *evdev = handle->private;
  76         struct evdev_client *client;
  77         struct input_event event;
  78         struct timespec ts;
  79
  80         ktime_get_ts(&ts);
  81         event.time.tv_sec = ts.tv_sec;
  82         event.time.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
  83         event.type = type;
  84         event.code = code;
  85         event.value = value;
  86
  87         rcu_read_lock();
  88
  89         client = rcu_dereference(evdev->grab);
  90         if (client)
  91                 evdev_pass_event(client, &event);
  92         else
  93                 list_for_each_entry_rcu(client, &evdev->client_list, node)
  94                         evdev_pass_event(client, &event);
  95
  96         rcu_read_unlock();
  97
  98         wake_up_interruptible(&evdev->wait);
  99 }
 100
 101 static int evdev_fasync(int fd, struct file *file, int on)
 102 {
 103         struct evdev_client *client = file->private_data;
 104
 105         return fasync_helper(fd, file, on, &client->fasync);
 106 }
 107
 108 static int evdev_flush(struct file *file, fl_owner_t id)
 109 {
 110         struct evdev_client *client = file->private_data;
 111         struct evdev *evdev = client->evdev;
 112         int retval;
 113
 114         retval = mutex_lock_interruptible(&evdev->mutex);
 115         if (retval)
 116                 return retval;
 117
 118         if (!evdev->exist)
 119                 retval = -ENODEV;
 120         else
 121                 retval = input_flush_device(&evdev->handle, file);
 122
 123         mutex_unlock(&evdev->mutex);
 124         return retval;
 125 }
 126
 127 static void evdev_free(struct device *dev)
 128 {
 129         struct evdev *evdev = container_of(dev, struct evdev, dev);
 130
 131         input_put_device(evdev->handle.dev);
 132         kfree(evdev);
 133 }
 134
 135 /*
 136  * Grabs an event device (along with underlying input device).
 137  * This function is called with evdev->mutex taken.
 138  */
 139 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 140 {
 141         int error;
 142
 143         if (evdev->grab)
 144                 return -EBUSY;
 145
 146         error = input_grab_device(&evdev->handle);
 147         if (error)
 148                 return error;
 149
 150         rcu_assign_pointer(evdev->grab, client);
 151         synchronize_rcu();
 152
 153         return 0;
 154 }
 155
 156 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 157 {
 158         if (evdev->grab != client)
 159                 return  -EINVAL;
 160
 161         rcu_assign_pointer(evdev->grab, NULL);
 162         synchronize_rcu();
 163         input_release_device(&evdev->handle);
 164
 165         return 0;
 166 }
 167
 168 static void evdev_attach_client(struct evdev *evdev,
 169                                 struct evdev_client *client)
 170 {
 171         spin_lock(&evdev->client_lock);
 172         list_add_tail_rcu(&client->node, &evdev->client_list);
 173         spin_unlock(&evdev->client_lock);
 174         synchronize_rcu();
 175 }
 176
 177 static void evdev_detach_client(struct evdev *evdev,
 178                                 struct evdev_client *client)
 179 {
 180         spin_lock(&evdev->client_lock);
 181         list_del_rcu(&client->node);
 182         spin_unlock(&evdev->client_lock);
 183         synchronize_rcu();
 184 }
 185
 186 static int evdev_open_device(struct evdev *evdev)
 187 {
 188         int retval;
 189
 190         retval = mutex_lock_interruptible(&evdev->mutex);
 191         if (retval)
 192                 return retval;
 193
 194         if (!evdev->exist)
 195                 retval = -ENODEV;
 196         else if (!evdev->open++) {
 197                 retval = input_open_device(&evdev->handle);
 198                 if (retval)
 199                         evdev->open--;
 200         }
 201
 202         mutex_unlock(&evdev->mutex);
 203         return retval;
 204 }
 205
 206 static void evdev_close_device(struct evdev *evdev)
 207 {
 208         mutex_lock(&evdev->mutex);
 209
 210         if (evdev->exist && !--evdev->open)
 211                 input_close_device(&evdev->handle);
 212
 213         mutex_unlock(&evdev->mutex);
 214 }
 215
 216 /*
 217  * Wake up users waiting for IO so they can disconnect from
 218  * dead device.
 219  */
 220 static void evdev_hangup(struct evdev *evdev)
 221 {
 222         struct evdev_client *client;
 223
 224         spin_lock(&evdev->client_lock);
 225         list_for_each_entry(client, &evdev->client_list, node)
 226                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 227         spin_unlock(&evdev->client_lock);
 228
 229         wake_up_interruptible(&evdev->wait);
 230 }
 231
 232 static int evdev_release(struct inode *inode, struct file *file)
 233 {
 234         struct evdev_client *client = file->private_data;
 235         struct evdev *evdev = client->evdev;
 236
 237         mutex_lock(&evdev->mutex);
 238         if (evdev->grab == client)
 239                 evdev_ungrab(evdev, client);
 240         mutex_unlock(&evdev->mutex);
 241
 242         evdev_detach_client(evdev, client);
 243         wake_lock_destroy(&client->wake_lock);
 244         kfree(client);
 245
 246         evdev_close_device(evdev);
 247         put_device(&evdev->dev);
 248
 249         return 0;
 250 }
 251
 252 static int evdev_open(struct inode *inode, struct file *file)
 253 {
 254         struct evdev *evdev;
 255         struct evdev_client *client;
 256         int i = iminor(inode) - EVDEV_MINOR_BASE;
 257         int error;
 258
 259         if (i >= EVDEV_MINORS)
 260                 return -ENODEV;
 261
 262         error = mutex_lock_interruptible(&evdev_table_mutex);
 263         if (error)
 264                 return error;
 265         evdev = evdev_table[i];
 266         if (evdev)
 267                 get_device(&evdev->dev);
 268         mutex_unlock(&evdev_table_mutex);
 269
 270         if (!evdev)
 271                 return -ENODEV;
 272
 273         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
 274         if (!client) {
 275                 error = -ENOMEM;
 276                 goto err_put_evdev;
 277         }
 278
 279         spin_lock_init(&client->buffer_lock);
 280         snprintf(client->name, sizeof(client->name), "%s-%d",
 281                         dev_name(&evdev->dev), task_tgid_vnr(current));
 282         wake_lock_init(&client->wake_lock, WAKE_LOCK_SUSPEND, client->name);
 283         client->evdev = evdev;
 284         evdev_attach_client(evdev, client);
 285
 286         error = evdev_open_device(evdev);
 287         if (error)
 288                 goto err_free_client;
 289
 290         file->private_data = client;
 291         return 0;
 292
 293  err_free_client:
 294         evdev_detach_client(evdev, client);
 295         kfree(client);
 296  err_put_evdev:
 297         put_device(&evdev->dev);
 298         return error;
 299 }
 300
 301 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 302                            size_t count, loff_t *ppos)
 303 {
 304         struct evdev_client *client = file->private_data;
 305         struct evdev *evdev = client->evdev;
 306         struct input_event event;
 307         int retval;
 308
 309         retval = mutex_lock_interruptible(&evdev->mutex);
 310         if (retval)
 311                 return retval;
 312
 313         if (!evdev->exist) {
 314                 retval = -ENODEV;
 315                 goto out;
 316         }
 317
 318         while (retval < count) {
 319
 320                 if (input_event_from_user(buffer + retval, &event)) {
 321                         retval = -EFAULT;
 322                         goto out;
 323                 }
 324
 325                 input_inject_event(&evdev->handle,
 326                                    event.type, event.code, event.value);
 327                 retval += input_event_size();
 328         }
 329
 330  out:
 331         mutex_unlock(&evdev->mutex);
 332         return retval;
 333 }
 334
 335 static int evdev_fetch_next_event(struct evdev_client *client,
 336                                   struct input_event *event)
 337 {
 338         int have_event;
 339
 340         spin_lock_irq(&client->buffer_lock);
 341
 342         have_event = client->head != client->tail;
 343         if (have_event) {
 344                 *event = client->buffer[client->tail++];
 345                 client->tail &= EVDEV_BUFFER_SIZE - 1;
 346                 if (client->head == client->tail)
 347                         wake_unlock(&client->wake_lock);
 348         }
 349
 350         spin_unlock_irq(&client->buffer_lock);
 351
 352         return have_event;
 353 }
 354
 355 static ssize_t evdev_read(struct file *file, char __user *buffer,
 356                           size_t count, loff_t *ppos)
 357 {
 358         struct evdev_client *client = file->private_data;
 359         struct evdev *evdev = client->evdev;
 360         struct input_event event;
 361         int retval;
 362
 363         if (count < input_event_size())
 364                 return -EINVAL;
 365
 366         if (client->head == client->tail && evdev->exist &&
 367             (file->f_flags & O_NONBLOCK))
 368                 return -EAGAIN;
 369
 370         retval = wait_event_interruptible(evdev->wait,
 371                 client->head != client->tail || !evdev->exist);
 372         if (retval)
 373                 return retval;
 374
 375         if (!evdev->exist)
 376                 return -ENODEV;
 377
 378         while (retval + input_event_size() <= count &&
 379                evdev_fetch_next_event(client, &event)) {
 380
 381                 if (input_event_to_user(buffer + retval, &event))
 382                         return -EFAULT;
 383
 384                 retval += input_event_size();
 385         }
 386
 387         return retval;
 388 }
 389
 390 /* No kernel lock - fine */
 391 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 392 {
 393         struct evdev_client *client = file->private_data;
 394         struct evdev *evdev = client->evdev;
 395
 396         poll_wait(file, &evdev->wait, wait);
 397         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 398                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
 399 }
 400
 401 #ifdef CONFIG_COMPAT
 402
 403 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 404 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 405
 406 #ifdef __BIG_ENDIAN
 407 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 408                         unsigned int maxlen, void __user *p, int compat)
 409 {
 410         int len, i;
 411
 412         if (compat) {
 413                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 414                 if (len > maxlen)
 415                         len = maxlen;
 416
 417                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 418                         if (copy_to_user((compat_long_t __user *) p + i,
 419                                          (compat_long_t *) bits +
 420                                                 i + 1 - ((i % 2) << 1),
 421                                          sizeof(compat_long_t)))
 422                                 return -EFAULT;
 423         } else {
 424                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 425                 if (len > maxlen)
 426                         len = maxlen;
 427
 428                 if (copy_to_user(p, bits, len))
 429                         return -EFAULT;
 430         }
 431
 432         return len;
 433 }
 434 #else
 435 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 436                         unsigned int maxlen, void __user *p, int compat)
 437 {
 438         int len = compat ?
 439                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 440                         BITS_TO_LONGS(maxbit) * sizeof(long);
 441
 442         if (len > maxlen)
 443                 len = maxlen;
 444
 445         return copy_to_user(p, bits, len) ? -EFAULT : len;
 446 }
 447 #endif /* __BIG_ENDIAN */
 448
 449 #else
 450
 451 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 452                         unsigned int maxlen, void __user *p, int compat)
 453 {
 454         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 455
 456         if (len > maxlen)
 457                 len = maxlen;
 458
 459         return copy_to_user(p, bits, len) ? -EFAULT : len;
 460 }
 461
 462 #endif /* CONFIG_COMPAT */
 463
 464 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 465 {
 466         int len;
 467
 468         if (!str)
 469                 return -ENOENT;
 470
 471         len = strlen(str) + 1;
 472         if (len > maxlen)
 473                 len = maxlen;
 474
 475         return copy_to_user(p, str, len) ? -EFAULT : len;
 476 }
 477
 478 #define OLD_KEY_MAX     0x1ff
 479 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
 480 {
 481         static unsigned long keymax_warn_time;
 482         unsigned long *bits;
 483         int len;
 484
 485         switch (_IOC_NR(cmd) & EV_MAX) {
 486
 487         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 488         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 489         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 490         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 491         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 492         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 493         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 494         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 495         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 496         default: return -EINVAL;
 497         }
 498
 499         /*
 500          * Work around bugs in userspace programs that like to do
 501          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 502          * should be in bytes, not in bits.
 503          */
 504         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
 505                 len = OLD_KEY_MAX;
 506                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 507                         printk(KERN_WARNING
 508                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
 509                                 "limiting output to %zu bytes. See "
 510                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 511                                 OLD_KEY_MAX,
 512                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 513         }
 514
 515         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 516 }
 517 #undef OLD_KEY_MAX
 518
 519 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 520                            void __user *p, int compat_mode)
 521 {
 522         struct evdev_client *client = file->private_data;
 523         struct evdev *evdev = client->evdev;
 524         struct input_dev *dev = evdev->handle.dev;
 525         struct input_absinfo abs;
 526         struct ff_effect effect;
 527         int __user *ip = (int __user *)p;
 528         int i, t, u, v;
 529         int error;
 530
 531         switch (cmd) {
 532
 533         case EVIOCGVERSION:
 534                 return put_user(EV_VERSION, ip);
 535
 536         case EVIOCGID:
 537                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 538                         return -EFAULT;
 539                 return 0;
 540
 541         case EVIOCGREP:
 542                 if (!test_bit(EV_REP, dev->evbit))
 543                         return -ENOSYS;
 544                 if (put_user(dev->rep[REP_DELAY], ip))
 545                         return -EFAULT;
 546                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 547                         return -EFAULT;
 548                 return 0;
 549
 550         case EVIOCSREP:
 551                 if (!test_bit(EV_REP, dev->evbit))
 552                         return -ENOSYS;
 553                 if (get_user(u, ip))
 554                         return -EFAULT;
 555                 if (get_user(v, ip + 1))
 556                         return -EFAULT;
 557
 558                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 559                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 560
 561                 return 0;
 562
 563         case EVIOCGKEYCODE:
 564                 if (get_user(t, ip))
 565                         return -EFAULT;
 566
 567                 error = input_get_keycode(dev, t, &v);
 568                 if (error)
 569                         return error;
 570
 571                 if (put_user(v, ip + 1))
 572                         return -EFAULT;
 573
 574                 return 0;
 575
 576         case EVIOCSKEYCODE:
 577                 if (get_user(t, ip) || get_user(v, ip + 1))
 578                         return -EFAULT;
 579
 580                 return input_set_keycode(dev, t, v);
 581
 582         case EVIOCRMFF:
 583                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 584
 585         case EVIOCGEFFECTS:
 586                 i = test_bit(EV_FF, dev->evbit) ?
 587                                 dev->ff->max_effects : 0;
 588                 if (put_user(i, ip))
 589                         return -EFAULT;
 590                 return 0;
 591
 592         case EVIOCGRAB:
 593                 if (p)
 594                         return evdev_grab(evdev, client);
 595                 else
 596                         return evdev_ungrab(evdev, client);
 597
 598         default:
 599
 600                 if (_IOC_TYPE(cmd) != 'E')
 601                         return -EINVAL;
 602
 603                 if (_IOC_DIR(cmd) == _IOC_READ) {
 604
 605                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 606                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
 607
 608                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 609                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 610                                                     p, compat_mode);
 611
 612                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 613                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 614                                                     p, compat_mode);
 615
 616                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 617                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 618                                                     p, compat_mode);
 619
 620                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 621                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 622                                                     p, compat_mode);
 623
 624                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 625                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
 626
 627                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 628                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
 629
 630                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 631                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
 632
 633                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 634
 635                                 t = _IOC_NR(cmd) & ABS_MAX;
 636
 637                                 abs.value = dev->abs[t];
 638                                 abs.minimum = dev->absmin[t];
 639                                 abs.maximum = dev->absmax[t];
 640                                 abs.fuzz = dev->absfuzz[t];
 641                                 abs.flat = dev->absflat[t];
 642                                 abs.resolution = dev->absres[t];
 643
 644                                 if (copy_to_user(p, &abs, min_t(size_t,
 645                                                                 _IOC_SIZE(cmd),
 646                                                                 sizeof(struct input_absinfo))))
 647                                         return -EFAULT;
 648
 649                                 return 0;
 650                         }
 651
 652                 }
 653
 654                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
 655
 656                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
 657
 658                                 if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
 659                                         return -EFAULT;
 660
 661                                 error = input_ff_upload(dev, &effect, file);
 662
 663                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 664                                         return -EFAULT;
 665
 666                                 return error;
 667                         }
 668
 669                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 670
 671                                 t = _IOC_NR(cmd) & ABS_MAX;
 672
 673                                 if (copy_from_user(&abs, p, min_t(size_t,
 674                                                                   _IOC_SIZE(cmd),
 675                                                                   sizeof(struct input_absinfo))))
 676                                         return -EFAULT;
 677
 678                                 /*
 679                                  * Take event lock to ensure that we are not
 680                                  * changing device parameters in the middle
 681                                  * of event.
 682                                  */
 683                                 spin_lock_irq(&dev->event_lock);
 684
 685                                 dev->abs[t] = abs.value;
 686                                 dev->absmin[t] = abs.minimum;
 687                                 dev->absmax[t] = abs.maximum;
 688                                 dev->absfuzz[t] = abs.fuzz;
 689                                 dev->absflat[t] = abs.flat;
 690                                 dev->absres[t] = _IOC_SIZE(cmd) < sizeof(struct input_absinfo) ?
 691                                                         0 : abs.resolution;
 692
 693                                 spin_unlock_irq(&dev->event_lock);
 694
 695                                 return 0;
 696                         }
 697                 }
 698         }
 699         return -EINVAL;
 700 }
 701
 702 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 703                                 void __user *p, int compat_mode)
 704 {
 705         struct evdev_client *client = file->private_data;
 706         struct evdev *evdev = client->evdev;
 707         int retval;
 708
 709         retval = mutex_lock_interruptible(&evdev->mutex);
 710         if (retval)
 711                 return retval;
 712
 713         if (!evdev->exist) {
 714                 retval = -ENODEV;
 715                 goto out;
 716         }
 717
 718         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 719
 720  out:
 721         mutex_unlock(&evdev->mutex);
 722         return retval;
 723 }
 724
 725 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 726 {
 727         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 728 }
 729
 730 #ifdef CONFIG_COMPAT
 731 static long evdev_ioctl_compat(struct file *file,
 732                                 unsigned int cmd, unsigned long arg)
 733 {
 734         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 735 }
 736 #endif
 737
 738 static const struct file_operations evdev_fops = {
 739         .owner          = THIS_MODULE,
 740         .read           = evdev_read,
 741         .write          = evdev_write,
 742         .poll           = evdev_poll,
 743         .open           = evdev_open,
 744         .release        = evdev_release,
 745         .unlocked_ioctl = evdev_ioctl,
 746 #ifdef CONFIG_COMPAT
 747         .compat_ioctl   = evdev_ioctl_compat,
 748 #endif
 749         .fasync         = evdev_fasync,
 750         .flush          = evdev_flush
 751 };
 752
 753 static int evdev_install_chrdev(struct evdev *evdev)
 754 {
 755         /*
 756          * No need to do any locking here as calls to connect and
 757          * disconnect are serialized by the input core
 758          */
 759         evdev_table[evdev->minor] = evdev;
 760         return 0;
 761 }
 762
 763 static void evdev_remove_chrdev(struct evdev *evdev)
 764 {
 765         /*
 766          * Lock evdev table to prevent race with evdev_open()
 767          */
 768         mutex_lock(&evdev_table_mutex);
 769         evdev_table[evdev->minor] = NULL;
 770         mutex_unlock(&evdev_table_mutex);
 771 }
 772
 773 /*
 774  * Mark device non-existent. This disables writes, ioctls and
 775  * prevents new users from opening the device. Already posted
 776  * blocking reads will stay, however new ones will fail.
 777  */
 778 static void evdev_mark_dead(struct evdev *evdev)
 779 {
 780         mutex_lock(&evdev->mutex);
 781         evdev->exist = 0;
 782         mutex_unlock(&evdev->mutex);
 783 }
 784
 785 static void evdev_cleanup(struct evdev *evdev)
 786 {
 787         struct input_handle *handle = &evdev->handle;
 788
 789         evdev_mark_dead(evdev);
 790         evdev_hangup(evdev);
 791         evdev_remove_chrdev(evdev);
 792
 793         /* evdev is marked dead so no one else accesses evdev->open */
 794         if (evdev->open) {
 795                 input_flush_device(handle, NULL);
 796                 input_close_device(handle);
 797         }
 798 }
 799
 800 /*
 801  * Create new evdev device. Note that input core serializes calls
 802  * to connect and disconnect so we don't need to lock evdev_table here.
 803  */
 804 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 805                          const struct input_device_id *id)
 806 {
 807         struct evdev *evdev;
 808         int minor;
 809         int error;
 810
 811         for (minor = 0; minor < EVDEV_MINORS; minor++)
 812                 if (!evdev_table[minor])
 813                         break;
 814
 815         if (minor == EVDEV_MINORS) {
 816                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 817                 return -ENFILE;
 818         }
 819
 820         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 821         if (!evdev)
 822                 return -ENOMEM;
 823
 824         INIT_LIST_HEAD(&evdev->client_list);
 825         spin_lock_init(&evdev->client_lock);
 826         mutex_init(&evdev->mutex);
 827         init_waitqueue_head(&evdev->wait);
 828
 829         dev_set_name(&evdev->dev, "event%d", minor);
 830         evdev->exist = 1;
 831         evdev->minor = minor;
 832
 833         evdev->handle.dev = input_get_device(dev);
 834         evdev->handle.name = dev_name(&evdev->dev);
 835         evdev->handle.handler = handler;
 836         evdev->handle.private = evdev;
 837
 838         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
 839         evdev->dev.class = &input_class;
 840         evdev->dev.parent = &dev->dev;
 841         evdev->dev.release = evdev_free;
 842         device_initialize(&evdev->dev);
 843
 844         error = input_register_handle(&evdev->handle);
 845         if (error)
 846                 goto err_free_evdev;
 847
 848         error = evdev_install_chrdev(evdev);
 849         if (error)
 850                 goto err_unregister_handle;
 851
 852         error = device_add(&evdev->dev);
 853         if (error)
 854                 goto err_cleanup_evdev;
 855
 856         return 0;
 857
 858  err_cleanup_evdev:
 859         evdev_cleanup(evdev);
 860  err_unregister_handle:
 861         input_unregister_handle(&evdev->handle);
 862  err_free_evdev:
 863         put_device(&evdev->dev);
 864         return error;
 865 }
 866
 867 static void evdev_disconnect(struct input_handle *handle)
 868 {
 869         struct evdev *evdev = handle->private;
 870
 871         device_del(&evdev->dev);
 872         evdev_cleanup(evdev);
 873         input_unregister_handle(handle);
 874         put_device(&evdev->dev);
 875 }
 876
 877 static const struct input_device_id evdev_ids[] = {
 878         { .driver_info = 1 },   /* Matches all devices */
 879         { },                    /* Terminating zero entry */
 880 };
 881
 882 MODULE_DEVICE_TABLE(input, evdev_ids);
 883
 884 static struct input_handler evdev_handler = {
 885         .event          = evdev_event,
 886         .connect        = evdev_connect,
 887         .disconnect     = evdev_disconnect,
 888         .fops           = &evdev_fops,
 889         .minor          = EVDEV_MINOR_BASE,
 890         .name           = "evdev",
 891         .id_table       = evdev_ids,
 892 };
 893
 894 static int __init evdev_init(void)
 895 {
 896         return input_register_handler(&evdev_handler);
 897 }
 898
 899 static void __exit evdev_exit(void)
 900 {
 901         input_unregister_handler(&evdev_handler);
 902 }
 903
 904 module_init(evdev_init);
 905 module_exit(evdev_exit);
 906
 907 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 908 MODULE_DESCRIPTION("Input driver event char devices");
 909 MODULE_LICENSE("GPL");