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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #define EVDEV_MINOR_BASE        64
  14 #define EVDEV_MINORS            32
  15 #define EVDEV_MIN_BUFFER_SIZE   64U
  16 #define EVDEV_BUF_PACKETS       8
  17
  18 #include <linux/poll.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/mm.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/input/mt.h>
  26 #include <linux/major.h>
  27 #include <linux/device.h>
  28 #include <linux/cdev.h>
  29 #include "input-compat.h"
  30
  31 enum evdev_clock_type {
  32         EV_CLK_REAL = 0,
  33         EV_CLK_MONO,
  34         EV_CLK_BOOT,
  35         EV_CLK_MAX
  36 };
  37
  38 struct evdev {
  39         int open;
  40         struct input_handle handle;
  41         wait_queue_head_t wait;
  42         struct evdev_client __rcu *grab;
  43         struct list_head client_list;
  44         spinlock_t client_lock; /* protects client_list */
  45         struct mutex mutex;
  46         struct device dev;
  47         struct cdev cdev;
  48         bool exist;
  49 };
  50
  51 struct evdev_client {
  52         unsigned int head;
  53         unsigned int tail;
  54         unsigned int packet_head; /* [future] position of the first element of next packet */
  55         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  56         struct fasync_struct *fasync;
  57         struct evdev *evdev;
  58         struct list_head node;
  59         int clk_type;
  60         bool revoked;
  61         unsigned long *evmasks[EV_CNT];
  62         unsigned int bufsize;
  63         struct input_event buffer[];
  64 };
  65
  66 static size_t evdev_get_mask_cnt(unsigned int type)
  67 {
  68         static const size_t counts[EV_CNT] = {
  69                 /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
  70                 [EV_SYN]        = EV_CNT,
  71                 [EV_KEY]        = KEY_CNT,
  72                 [EV_REL]        = REL_CNT,
  73                 [EV_ABS]        = ABS_CNT,
  74                 [EV_MSC]        = MSC_CNT,
  75                 [EV_SW]         = SW_CNT,
  76                 [EV_LED]        = LED_CNT,
  77                 [EV_SND]        = SND_CNT,
  78                 [EV_FF]         = FF_CNT,
  79         };
  80
  81         return (type < EV_CNT) ? counts[type] : 0;
  82 }
  83
  84 /* requires the buffer lock to be held */
  85 static bool __evdev_is_filtered(struct evdev_client *client,
  86                                 unsigned int type,
  87                                 unsigned int code)
  88 {
  89         unsigned long *mask;
  90         size_t cnt;
  91
  92         /* EV_SYN and unknown codes are never filtered */
  93         if (type == EV_SYN || type >= EV_CNT)
  94                 return false;
  95
  96         /* first test whether the type is filtered */
  97         mask = client->evmasks[0];
  98         if (mask && !test_bit(type, mask))
  99                 return true;
 100
 101         /* unknown values are never filtered */
 102         cnt = evdev_get_mask_cnt(type);
 103         if (!cnt || code >= cnt)
 104                 return false;
 105
 106         mask = client->evmasks[type];
 107         return mask && !test_bit(code, mask);
 108 }
 109
 110 /* flush queued events of type @type, caller must hold client->buffer_lock */
 111 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
 112 {
 113         unsigned int i, head, num;
 114         unsigned int mask = client->bufsize - 1;
 115         bool is_report;
 116         struct input_event *ev;
 117
 118         BUG_ON(type == EV_SYN);
 119
 120         head = client->tail;
 121         client->packet_head = client->tail;
 122
 123         /* init to 1 so a leading SYN_REPORT will not be dropped */
 124         num = 1;
 125
 126         for (i = client->tail; i != client->head; i = (i + 1) & mask) {
 127                 ev = &client->buffer[i];
 128                 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
 129
 130                 if (ev->type == type) {
 131                         /* drop matched entry */
 132                         continue;
 133                 } else if (is_report && !num) {
 134                         /* drop empty SYN_REPORT groups */
 135                         continue;
 136                 } else if (head != i) {
 137                         /* move entry to fill the gap */
 138                         client->buffer[head].time = ev->time;
 139                         client->buffer[head].type = ev->type;
 140                         client->buffer[head].code = ev->code;
 141                         client->buffer[head].value = ev->value;
 142                 }
 143
 144                 num++;
 145                 head = (head + 1) & mask;
 146
 147                 if (is_report) {
 148                         num = 0;
 149                         client->packet_head = head;
 150                 }
 151         }
 152
 153         client->head = head;
 154 }
 155
 156 static void __evdev_queue_syn_dropped(struct evdev_client *client)
 157 {
 158         struct input_event ev;
 159         ktime_t time;
 160
 161         time = client->clk_type == EV_CLK_REAL ?
 162                         ktime_get_real() :
 163                         client->clk_type == EV_CLK_MONO ?
 164                                 ktime_get() :
 165                                 ktime_get_boottime();
 166
 167         ev.time = ktime_to_timeval(time);
 168         ev.type = EV_SYN;
 169         ev.code = SYN_DROPPED;
 170         ev.value = 0;
 171
 172         client->buffer[client->head++] = ev;
 173         client->head &= client->bufsize - 1;
 174
 175         if (unlikely(client->head == client->tail)) {
 176                 /* drop queue but keep our SYN_DROPPED event */
 177                 client->tail = (client->head - 1) & (client->bufsize - 1);
 178                 client->packet_head = client->tail;
 179         }
 180 }
 181
 182 static void evdev_queue_syn_dropped(struct evdev_client *client)
 183 {
 184         unsigned long flags;
 185
 186         spin_lock_irqsave(&client->buffer_lock, flags);
 187         __evdev_queue_syn_dropped(client);
 188         spin_unlock_irqrestore(&client->buffer_lock, flags);
 189 }
 190
 191 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
 192 {
 193         unsigned long flags;
 194
 195         if (client->clk_type == clkid)
 196                 return 0;
 197
 198         switch (clkid) {
 199
 200         case CLOCK_REALTIME:
 201                 client->clk_type = EV_CLK_REAL;
 202                 break;
 203         case CLOCK_MONOTONIC:
 204                 client->clk_type = EV_CLK_MONO;
 205                 break;
 206         case CLOCK_BOOTTIME:
 207                 client->clk_type = EV_CLK_BOOT;
 208                 break;
 209         default:
 210                 return -EINVAL;
 211         }
 212
 213         /*
 214          * Flush pending events and queue SYN_DROPPED event,
 215          * but only if the queue is not empty.
 216          */
 217         spin_lock_irqsave(&client->buffer_lock, flags);
 218
 219         if (client->head != client->tail) {
 220                 client->packet_head = client->head = client->tail;
 221                 __evdev_queue_syn_dropped(client);
 222         }
 223
 224         spin_unlock_irqrestore(&client->buffer_lock, flags);
 225
 226         return 0;
 227 }
 228
 229 static void __pass_event(struct evdev_client *client,
 230                          const struct input_event *event)
 231 {
 232         client->buffer[client->head++] = *event;
 233         client->head &= client->bufsize - 1;
 234
 235         if (unlikely(client->head == client->tail)) {
 236                 /*
 237                  * This effectively "drops" all unconsumed events, leaving
 238                  * EV_SYN/SYN_DROPPED plus the newest event in the queue.
 239                  */
 240                 client->tail = (client->head - 2) & (client->bufsize - 1);
 241
 242                 client->buffer[client->tail].time = event->time;
 243                 client->buffer[client->tail].type = EV_SYN;
 244                 client->buffer[client->tail].code = SYN_DROPPED;
 245                 client->buffer[client->tail].value = 0;
 246
 247                 client->packet_head = client->tail;
 248         }
 249
 250         if (event->type == EV_SYN && event->code == SYN_REPORT) {
 251                 client->packet_head = client->head;
 252                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
 253         }
 254 }
 255
 256 static void evdev_pass_values(struct evdev_client *client,
 257                         const struct input_value *vals, unsigned int count,
 258                         ktime_t *ev_time)
 259 {
 260         struct evdev *evdev = client->evdev;
 261         const struct input_value *v;
 262         struct input_event event;
 263         bool wakeup = false;
 264
 265         if (client->revoked)
 266                 return;
 267
 268         event.time = ktime_to_timeval(ev_time[client->clk_type]);
 269
 270         /* Interrupts are disabled, just acquire the lock. */
 271         spin_lock(&client->buffer_lock);
 272
 273         for (v = vals; v != vals + count; v++) {
 274                 if (__evdev_is_filtered(client, v->type, v->code))
 275                         continue;
 276
 277                 if (v->type == EV_SYN && v->code == SYN_REPORT) {
 278                         /* drop empty SYN_REPORT */
 279                         if (client->packet_head == client->head)
 280                                 continue;
 281
 282                         wakeup = true;
 283                 }
 284
 285                 event.type = v->type;
 286                 event.code = v->code;
 287                 event.value = v->value;
 288                 __pass_event(client, &event);
 289         }
 290
 291         spin_unlock(&client->buffer_lock);
 292
 293         if (wakeup)
 294                 wake_up_interruptible(&evdev->wait);
 295 }
 296
 297 /*
 298  * Pass incoming events to all connected clients.
 299  */
 300 static void evdev_events(struct input_handle *handle,
 301                          const struct input_value *vals, unsigned int count)
 302 {
 303         struct evdev *evdev = handle->private;
 304         struct evdev_client *client;
 305         ktime_t ev_time[EV_CLK_MAX];
 306
 307         ev_time[EV_CLK_MONO] = ktime_get();
 308         ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
 309         ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
 310                                                  TK_OFFS_BOOT);
 311
 312         rcu_read_lock();
 313
 314         client = rcu_dereference(evdev->grab);
 315
 316         if (client)
 317                 evdev_pass_values(client, vals, count, ev_time);
 318         else
 319                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 320                         evdev_pass_values(client, vals, count, ev_time);
 321
 322         rcu_read_unlock();
 323 }
 324
 325 /*
 326  * Pass incoming event to all connected clients.
 327  */
 328 static void evdev_event(struct input_handle *handle,
 329                         unsigned int type, unsigned int code, int value)
 330 {
 331         struct input_value vals[] = { { type, code, value } };
 332
 333         evdev_events(handle, vals, 1);
 334 }
 335
 336 static int evdev_fasync(int fd, struct file *file, int on)
 337 {
 338         struct evdev_client *client = file->private_data;
 339
 340         return fasync_helper(fd, file, on, &client->fasync);
 341 }
 342
 343 static int evdev_flush(struct file *file, fl_owner_t id)
 344 {
 345         struct evdev_client *client = file->private_data;
 346         struct evdev *evdev = client->evdev;
 347
 348         mutex_lock(&evdev->mutex);
 349
 350         if (evdev->exist && !client->revoked)
 351                 input_flush_device(&evdev->handle, file);
 352
 353         mutex_unlock(&evdev->mutex);
 354         return 0;
 355 }
 356
 357 static void evdev_free(struct device *dev)
 358 {
 359         struct evdev *evdev = container_of(dev, struct evdev, dev);
 360
 361         input_put_device(evdev->handle.dev);
 362         kfree(evdev);
 363 }
 364
 365 /*
 366  * Grabs an event device (along with underlying input device).
 367  * This function is called with evdev->mutex taken.
 368  */
 369 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 370 {
 371         int error;
 372
 373         if (evdev->grab)
 374                 return -EBUSY;
 375
 376         error = input_grab_device(&evdev->handle);
 377         if (error)
 378                 return error;
 379
 380         rcu_assign_pointer(evdev->grab, client);
 381
 382         return 0;
 383 }
 384
 385 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 386 {
 387         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 388                                         lockdep_is_held(&evdev->mutex));
 389
 390         if (grab != client)
 391                 return  -EINVAL;
 392
 393         rcu_assign_pointer(evdev->grab, NULL);
 394         synchronize_rcu();
 395         input_release_device(&evdev->handle);
 396
 397         return 0;
 398 }
 399
 400 static void evdev_attach_client(struct evdev *evdev,
 401                                 struct evdev_client *client)
 402 {
 403         spin_lock(&evdev->client_lock);
 404         list_add_tail_rcu(&client->node, &evdev->client_list);
 405         spin_unlock(&evdev->client_lock);
 406 }
 407
 408 static void evdev_detach_client(struct evdev *evdev,
 409                                 struct evdev_client *client)
 410 {
 411         spin_lock(&evdev->client_lock);
 412         list_del_rcu(&client->node);
 413         spin_unlock(&evdev->client_lock);
 414         synchronize_rcu();
 415 }
 416
 417 static int evdev_open_device(struct evdev *evdev)
 418 {
 419         int retval;
 420
 421         retval = mutex_lock_interruptible(&evdev->mutex);
 422         if (retval)
 423                 return retval;
 424
 425         if (!evdev->exist)
 426                 retval = -ENODEV;
 427         else if (!evdev->open++) {
 428                 retval = input_open_device(&evdev->handle);
 429                 if (retval)
 430                         evdev->open--;
 431         }
 432
 433         mutex_unlock(&evdev->mutex);
 434         return retval;
 435 }
 436
 437 static void evdev_close_device(struct evdev *evdev)
 438 {
 439         mutex_lock(&evdev->mutex);
 440
 441         if (evdev->exist && !--evdev->open)
 442                 input_close_device(&evdev->handle);
 443
 444         mutex_unlock(&evdev->mutex);
 445 }
 446
 447 /*
 448  * Wake up users waiting for IO so they can disconnect from
 449  * dead device.
 450  */
 451 static void evdev_hangup(struct evdev *evdev)
 452 {
 453         struct evdev_client *client;
 454
 455         spin_lock(&evdev->client_lock);
 456         list_for_each_entry(client, &evdev->client_list, node)
 457                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 458         spin_unlock(&evdev->client_lock);
 459
 460         wake_up_interruptible(&evdev->wait);
 461 }
 462
 463 static int evdev_release(struct inode *inode, struct file *file)
 464 {
 465         struct evdev_client *client = file->private_data;
 466         struct evdev *evdev = client->evdev;
 467         unsigned int i;
 468
 469         mutex_lock(&evdev->mutex);
 470         evdev_ungrab(evdev, client);
 471         mutex_unlock(&evdev->mutex);
 472
 473         evdev_detach_client(evdev, client);
 474
 475         for (i = 0; i < EV_CNT; ++i)
 476                 kfree(client->evmasks[i]);
 477
 478         kvfree(client);
 479
 480         evdev_close_device(evdev);
 481
 482         return 0;
 483 }
 484
 485 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 486 {
 487         unsigned int n_events =
 488                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 489                     EVDEV_MIN_BUFFER_SIZE);
 490
 491         return roundup_pow_of_two(n_events);
 492 }
 493
 494 static int evdev_open(struct inode *inode, struct file *file)
 495 {
 496         struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
 497         unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 498         unsigned int size = sizeof(struct evdev_client) +
 499                                         bufsize * sizeof(struct input_event);
 500         struct evdev_client *client;
 501         int error;
 502
 503         client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
 504         if (!client)
 505                 client = vzalloc(size);
 506         if (!client)
 507                 return -ENOMEM;
 508
 509         client->bufsize = bufsize;
 510         spin_lock_init(&client->buffer_lock);
 511         client->evdev = evdev;
 512         evdev_attach_client(evdev, client);
 513
 514         error = evdev_open_device(evdev);
 515         if (error)
 516                 goto err_free_client;
 517
 518         file->private_data = client;
 519         nonseekable_open(inode, file);
 520
 521         return 0;
 522
 523  err_free_client:
 524         evdev_detach_client(evdev, client);
 525         kvfree(client);
 526         return error;
 527 }
 528
 529 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 530                            size_t count, loff_t *ppos)
 531 {
 532         struct evdev_client *client = file->private_data;
 533         struct evdev *evdev = client->evdev;
 534         struct input_event event;
 535         int retval = 0;
 536
 537         if (count != 0 && count < input_event_size())
 538                 return -EINVAL;
 539
 540         retval = mutex_lock_interruptible(&evdev->mutex);
 541         if (retval)
 542                 return retval;
 543
 544         if (!evdev->exist || client->revoked) {
 545                 retval = -ENODEV;
 546                 goto out;
 547         }
 548
 549         while (retval + input_event_size() <= count) {
 550
 551                 if (input_event_from_user(buffer + retval, &event)) {
 552                         retval = -EFAULT;
 553                         goto out;
 554                 }
 555                 retval += input_event_size();
 556
 557                 input_inject_event(&evdev->handle,
 558                                    event.type, event.code, event.value);
 559         }
 560
 561  out:
 562         mutex_unlock(&evdev->mutex);
 563         return retval;
 564 }
 565
 566 static int evdev_fetch_next_event(struct evdev_client *client,
 567                                   struct input_event *event)
 568 {
 569         int have_event;
 570
 571         spin_lock_irq(&client->buffer_lock);
 572
 573         have_event = client->packet_head != client->tail;
 574         if (have_event) {
 575                 *event = client->buffer[client->tail++];
 576                 client->tail &= client->bufsize - 1;
 577         }
 578
 579         spin_unlock_irq(&client->buffer_lock);
 580
 581         return have_event;
 582 }
 583
 584 static ssize_t evdev_read(struct file *file, char __user *buffer,
 585                           size_t count, loff_t *ppos)
 586 {
 587         struct evdev_client *client = file->private_data;
 588         struct evdev *evdev = client->evdev;
 589         struct input_event event;
 590         size_t read = 0;
 591         int error;
 592
 593         if (count != 0 && count < input_event_size())
 594                 return -EINVAL;
 595
 596         for (;;) {
 597                 if (!evdev->exist || client->revoked)
 598                         return -ENODEV;
 599
 600                 if (client->packet_head == client->tail &&
 601                     (file->f_flags & O_NONBLOCK))
 602                         return -EAGAIN;
 603
 604                 /*
 605                  * count == 0 is special - no IO is done but we check
 606                  * for error conditions (see above).
 607                  */
 608                 if (count == 0)
 609                         break;
 610
 611                 while (read + input_event_size() <= count &&
 612                        evdev_fetch_next_event(client, &event)) {
 613
 614                         if (input_event_to_user(buffer + read, &event))
 615                                 return -EFAULT;
 616
 617                         read += input_event_size();
 618                 }
 619
 620                 if (read)
 621                         break;
 622
 623                 if (!(file->f_flags & O_NONBLOCK)) {
 624                         error = wait_event_interruptible(evdev->wait,
 625                                         client->packet_head != client->tail ||
 626                                         !evdev->exist || client->revoked);
 627                         if (error)
 628                                 return error;
 629                 }
 630         }
 631
 632         return read;
 633 }
 634
 635 /* No kernel lock - fine */
 636 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 637 {
 638         struct evdev_client *client = file->private_data;
 639         struct evdev *evdev = client->evdev;
 640         unsigned int mask;
 641
 642         poll_wait(file, &evdev->wait, wait);
 643
 644         if (evdev->exist && !client->revoked)
 645                 mask = POLLOUT | POLLWRNORM;
 646         else
 647                 mask = POLLHUP | POLLERR;
 648
 649         if (client->packet_head != client->tail)
 650                 mask |= POLLIN | POLLRDNORM;
 651
 652         return mask;
 653 }
 654
 655 #ifdef CONFIG_COMPAT
 656
 657 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 658 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 659
 660 #ifdef __BIG_ENDIAN
 661 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 662                         unsigned int maxlen, void __user *p, int compat)
 663 {
 664         int len, i;
 665
 666         if (compat) {
 667                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 668                 if (len > maxlen)
 669                         len = maxlen;
 670
 671                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 672                         if (copy_to_user((compat_long_t __user *) p + i,
 673                                          (compat_long_t *) bits +
 674                                                 i + 1 - ((i % 2) << 1),
 675                                          sizeof(compat_long_t)))
 676                                 return -EFAULT;
 677         } else {
 678                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 679                 if (len > maxlen)
 680                         len = maxlen;
 681
 682                 if (copy_to_user(p, bits, len))
 683                         return -EFAULT;
 684         }
 685
 686         return len;
 687 }
 688
 689 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 690                           unsigned int maxlen, const void __user *p, int compat)
 691 {
 692         int len, i;
 693
 694         if (compat) {
 695                 if (maxlen % sizeof(compat_long_t))
 696                         return -EINVAL;
 697
 698                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 699                 if (len > maxlen)
 700                         len = maxlen;
 701
 702                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 703                         if (copy_from_user((compat_long_t *) bits +
 704                                                 i + 1 - ((i % 2) << 1),
 705                                            (compat_long_t __user *) p + i,
 706                                            sizeof(compat_long_t)))
 707                                 return -EFAULT;
 708                 if (i % 2)
 709                         *((compat_long_t *) bits + i - 1) = 0;
 710
 711         } else {
 712                 if (maxlen % sizeof(long))
 713                         return -EINVAL;
 714
 715                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 716                 if (len > maxlen)
 717                         len = maxlen;
 718
 719                 if (copy_from_user(bits, p, len))
 720                         return -EFAULT;
 721         }
 722
 723         return len;
 724 }
 725
 726 #else
 727
 728 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 729                         unsigned int maxlen, void __user *p, int compat)
 730 {
 731         int len = compat ?
 732                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 733                         BITS_TO_LONGS(maxbit) * sizeof(long);
 734
 735         if (len > maxlen)
 736                 len = maxlen;
 737
 738         return copy_to_user(p, bits, len) ? -EFAULT : len;
 739 }
 740
 741 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 742                           unsigned int maxlen, const void __user *p, int compat)
 743 {
 744         size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
 745         int len;
 746
 747         if (maxlen % chunk_size)
 748                 return -EINVAL;
 749
 750         len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
 751         len *= chunk_size;
 752         if (len > maxlen)
 753                 len = maxlen;
 754
 755         return copy_from_user(bits, p, len) ? -EFAULT : len;
 756 }
 757
 758 #endif /* __BIG_ENDIAN */
 759
 760 #else
 761
 762 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 763                         unsigned int maxlen, void __user *p, int compat)
 764 {
 765         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 766
 767         if (len > maxlen)
 768                 len = maxlen;
 769
 770         return copy_to_user(p, bits, len) ? -EFAULT : len;
 771 }
 772
 773 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 774                           unsigned int maxlen, const void __user *p, int compat)
 775 {
 776         int len;
 777
 778         if (maxlen % sizeof(long))
 779                 return -EINVAL;
 780
 781         len = BITS_TO_LONGS(maxbit) * sizeof(long);
 782         if (len > maxlen)
 783                 len = maxlen;
 784
 785         return copy_from_user(bits, p, len) ? -EFAULT : len;
 786 }
 787
 788 #endif /* CONFIG_COMPAT */
 789
 790 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 791 {
 792         int len;
 793
 794         if (!str)
 795                 return -ENOENT;
 796
 797         len = strlen(str) + 1;
 798         if (len > maxlen)
 799                 len = maxlen;
 800
 801         return copy_to_user(p, str, len) ? -EFAULT : len;
 802 }
 803
 804 static int handle_eviocgbit(struct input_dev *dev,
 805                             unsigned int type, unsigned int size,
 806                             void __user *p, int compat_mode)
 807 {
 808         unsigned long *bits;
 809         int len;
 810
 811         switch (type) {
 812
 813         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 814         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 815         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 816         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 817         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 818         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 819         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 820         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 821         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 822         default: return -EINVAL;
 823         }
 824
 825         return bits_to_user(bits, len, size, p, compat_mode);
 826 }
 827
 828 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 829 {
 830         struct input_keymap_entry ke = {
 831                 .len    = sizeof(unsigned int),
 832                 .flags  = 0,
 833         };
 834         int __user *ip = (int __user *)p;
 835         int error;
 836
 837         /* legacy case */
 838         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 839                 return -EFAULT;
 840
 841         error = input_get_keycode(dev, &ke);
 842         if (error)
 843                 return error;
 844
 845         if (put_user(ke.keycode, ip + 1))
 846                 return -EFAULT;
 847
 848         return 0;
 849 }
 850
 851 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 852 {
 853         struct input_keymap_entry ke;
 854         int error;
 855
 856         if (copy_from_user(&ke, p, sizeof(ke)))
 857                 return -EFAULT;
 858
 859         error = input_get_keycode(dev, &ke);
 860         if (error)
 861                 return error;
 862
 863         if (copy_to_user(p, &ke, sizeof(ke)))
 864                 return -EFAULT;
 865
 866         return 0;
 867 }
 868
 869 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 870 {
 871         struct input_keymap_entry ke = {
 872                 .len    = sizeof(unsigned int),
 873                 .flags  = 0,
 874         };
 875         int __user *ip = (int __user *)p;
 876
 877         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 878                 return -EFAULT;
 879
 880         if (get_user(ke.keycode, ip + 1))
 881                 return -EFAULT;
 882
 883         return input_set_keycode(dev, &ke);
 884 }
 885
 886 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 887 {
 888         struct input_keymap_entry ke;
 889
 890         if (copy_from_user(&ke, p, sizeof(ke)))
 891                 return -EFAULT;
 892
 893         if (ke.len > sizeof(ke.scancode))
 894                 return -EINVAL;
 895
 896         return input_set_keycode(dev, &ke);
 897 }
 898
 899 /*
 900  * If we transfer state to the user, we should flush all pending events
 901  * of the same type from the client's queue. Otherwise, they might end up
 902  * with duplicate events, which can screw up client's state tracking.
 903  * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
 904  * event so user-space will notice missing events.
 905  *
 906  * LOCKING:
 907  * We need to take event_lock before buffer_lock to avoid dead-locks. But we
 908  * need the even_lock only to guarantee consistent state. We can safely release
 909  * it while flushing the queue. This allows input-core to handle filters while
 910  * we flush the queue.
 911  */
 912 static int evdev_handle_get_val(struct evdev_client *client,
 913                                 struct input_dev *dev, unsigned int type,
 914                                 unsigned long *bits, unsigned int maxbit,
 915                                 unsigned int maxlen, void __user *p,
 916                                 int compat)
 917 {
 918         int ret;
 919         unsigned long *mem;
 920         size_t len;
 921
 922         len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
 923         mem = kmalloc(len, GFP_KERNEL);
 924         if (!mem)
 925                 return -ENOMEM;
 926
 927         spin_lock_irq(&dev->event_lock);
 928         spin_lock(&client->buffer_lock);
 929
 930         memcpy(mem, bits, len);
 931
 932         spin_unlock(&dev->event_lock);
 933
 934         __evdev_flush_queue(client, type);
 935
 936         spin_unlock_irq(&client->buffer_lock);
 937
 938         ret = bits_to_user(mem, maxbit, maxlen, p, compat);
 939         if (ret < 0)
 940                 evdev_queue_syn_dropped(client);
 941
 942         kfree(mem);
 943
 944         return ret;
 945 }
 946
 947 static int evdev_handle_mt_request(struct input_dev *dev,
 948                                    unsigned int size,
 949                                    int __user *ip)
 950 {
 951         const struct input_mt *mt = dev->mt;
 952         unsigned int code;
 953         int max_slots;
 954         int i;
 955
 956         if (get_user(code, &ip[0]))
 957                 return -EFAULT;
 958         if (!mt || !input_is_mt_value(code))
 959                 return -EINVAL;
 960
 961         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 962         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 963                 int value = input_mt_get_value(&mt->slots[i], code);
 964                 if (put_user(value, &ip[1 + i]))
 965                         return -EFAULT;
 966         }
 967
 968         return 0;
 969 }
 970
 971 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
 972                         struct file *file)
 973 {
 974         client->revoked = true;
 975         evdev_ungrab(evdev, client);
 976         input_flush_device(&evdev->handle, file);
 977         wake_up_interruptible(&evdev->wait);
 978
 979         return 0;
 980 }
 981
 982 /* must be called with evdev-mutex held */
 983 static int evdev_set_mask(struct evdev_client *client,
 984                           unsigned int type,
 985                           const void __user *codes,
 986                           u32 codes_size,
 987                           int compat)
 988 {
 989         unsigned long flags, *mask, *oldmask;
 990         size_t cnt;
 991         int error;
 992
 993         /* we allow unknown types and 'codes_size > size' for forward-compat */
 994         cnt = evdev_get_mask_cnt(type);
 995         if (!cnt)
 996                 return 0;
 997
 998         mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL);
 999         if (!mask)
1000                 return -ENOMEM;
1001
1002         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1003         if (error < 0) {
1004                 kfree(mask);
1005                 return error;
1006         }
1007
1008         spin_lock_irqsave(&client->buffer_lock, flags);
1009         oldmask = client->evmasks[type];
1010         client->evmasks[type] = mask;
1011         spin_unlock_irqrestore(&client->buffer_lock, flags);
1012
1013         kfree(oldmask);
1014
1015         return 0;
1016 }
1017
1018 /* must be called with evdev-mutex held */
1019 static int evdev_get_mask(struct evdev_client *client,
1020                           unsigned int type,
1021                           void __user *codes,
1022                           u32 codes_size,
1023                           int compat)
1024 {
1025         unsigned long *mask;
1026         size_t cnt, size, xfer_size;
1027         int i;
1028         int error;
1029
1030         /* we allow unknown types and 'codes_size > size' for forward-compat */
1031         cnt = evdev_get_mask_cnt(type);
1032         size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1033         xfer_size = min_t(size_t, codes_size, size);
1034
1035         if (cnt > 0) {
1036                 mask = client->evmasks[type];
1037                 if (mask) {
1038                         error = bits_to_user(mask, cnt - 1,
1039                                              xfer_size, codes, compat);
1040                         if (error < 0)
1041                                 return error;
1042                 } else {
1043                         /* fake mask with all bits set */
1044                         for (i = 0; i < xfer_size; i++)
1045                                 if (put_user(0xffU, (u8 __user *)codes + i))
1046                                         return -EFAULT;
1047                 }
1048         }
1049
1050         if (xfer_size < codes_size)
1051                 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1052                         return -EFAULT;
1053
1054         return 0;
1055 }
1056
1057 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1058                            void __user *p, int compat_mode)
1059 {
1060         struct evdev_client *client = file->private_data;
1061         struct evdev *evdev = client->evdev;
1062         struct input_dev *dev = evdev->handle.dev;
1063         struct input_absinfo abs;
1064         struct input_mask mask;
1065         struct ff_effect effect;
1066         int __user *ip = (int __user *)p;
1067         unsigned int i, t, u, v;
1068         unsigned int size;
1069         int error;
1070
1071         /* First we check for fixed-length commands */
1072         switch (cmd) {
1073
1074         case EVIOCGVERSION:
1075                 return put_user(EV_VERSION, ip);
1076
1077         case EVIOCGID:
1078                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1079                         return -EFAULT;
1080                 return 0;
1081
1082         case EVIOCGREP:
1083                 if (!test_bit(EV_REP, dev->evbit))
1084                         return -ENOSYS;
1085                 if (put_user(dev->rep[REP_DELAY], ip))
1086                         return -EFAULT;
1087                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1088                         return -EFAULT;
1089                 return 0;
1090
1091         case EVIOCSREP:
1092                 if (!test_bit(EV_REP, dev->evbit))
1093                         return -ENOSYS;
1094                 if (get_user(u, ip))
1095                         return -EFAULT;
1096                 if (get_user(v, ip + 1))
1097                         return -EFAULT;
1098
1099                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1100                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1101
1102                 return 0;
1103
1104         case EVIOCRMFF:
1105                 return input_ff_erase(dev, (int)(unsigned long) p, file);
1106
1107         case EVIOCGEFFECTS:
1108                 i = test_bit(EV_FF, dev->evbit) ?
1109                                 dev->ff->max_effects : 0;
1110                 if (put_user(i, ip))
1111                         return -EFAULT;
1112                 return 0;
1113
1114         case EVIOCGRAB:
1115                 if (p)
1116                         return evdev_grab(evdev, client);
1117                 else
1118                         return evdev_ungrab(evdev, client);
1119
1120         case EVIOCREVOKE:
1121                 if (p)
1122                         return -EINVAL;
1123                 else
1124                         return evdev_revoke(evdev, client, file);
1125
1126         case EVIOCGMASK: {
1127                 void __user *codes_ptr;
1128
1129                 if (copy_from_user(&mask, p, sizeof(mask)))
1130                         return -EFAULT;
1131
1132                 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1133                 return evdev_get_mask(client,
1134                                       mask.type, codes_ptr, mask.codes_size,
1135                                       compat_mode);
1136         }
1137
1138         case EVIOCSMASK: {
1139                 const void __user *codes_ptr;
1140
1141                 if (copy_from_user(&mask, p, sizeof(mask)))
1142                         return -EFAULT;
1143
1144                 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1145                 return evdev_set_mask(client,
1146                                       mask.type, codes_ptr, mask.codes_size,
1147                                       compat_mode);
1148         }
1149
1150         case EVIOCSCLOCKID:
1151                 if (copy_from_user(&i, p, sizeof(unsigned int)))
1152                         return -EFAULT;
1153
1154                 return evdev_set_clk_type(client, i);
1155
1156         case EVIOCGKEYCODE:
1157                 return evdev_handle_get_keycode(dev, p);
1158
1159         case EVIOCSKEYCODE:
1160                 return evdev_handle_set_keycode(dev, p);
1161
1162         case EVIOCGKEYCODE_V2:
1163                 return evdev_handle_get_keycode_v2(dev, p);
1164
1165         case EVIOCSKEYCODE_V2:
1166                 return evdev_handle_set_keycode_v2(dev, p);
1167         }
1168
1169         size = _IOC_SIZE(cmd);
1170
1171         /* Now check variable-length commands */
1172 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1173         switch (EVIOC_MASK_SIZE(cmd)) {
1174
1175         case EVIOCGPROP(0):
1176                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1177                                     size, p, compat_mode);
1178
1179         case EVIOCGMTSLOTS(0):
1180                 return evdev_handle_mt_request(dev, size, ip);
1181
1182         case EVIOCGKEY(0):
1183                 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1184                                             KEY_MAX, size, p, compat_mode);
1185
1186         case EVIOCGLED(0):
1187                 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1188                                             LED_MAX, size, p, compat_mode);
1189
1190         case EVIOCGSND(0):
1191                 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1192                                             SND_MAX, size, p, compat_mode);
1193
1194         case EVIOCGSW(0):
1195                 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1196                                             SW_MAX, size, p, compat_mode);
1197
1198         case EVIOCGNAME(0):
1199                 return str_to_user(dev->name, size, p);
1200
1201         case EVIOCGPHYS(0):
1202                 return str_to_user(dev->phys, size, p);
1203
1204         case EVIOCGUNIQ(0):
1205                 return str_to_user(dev->uniq, size, p);
1206
1207         case EVIOC_MASK_SIZE(EVIOCSFF):
1208                 if (input_ff_effect_from_user(p, size, &effect))
1209                         return -EFAULT;
1210
1211                 error = input_ff_upload(dev, &effect, file);
1212                 if (error)
1213                         return error;
1214
1215                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1216                         return -EFAULT;
1217
1218                 return 0;
1219         }
1220
1221         /* Multi-number variable-length handlers */
1222         if (_IOC_TYPE(cmd) != 'E')
1223                 return -EINVAL;
1224
1225         if (_IOC_DIR(cmd) == _IOC_READ) {
1226
1227                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1228                         return handle_eviocgbit(dev,
1229                                                 _IOC_NR(cmd) & EV_MAX, size,
1230                                                 p, compat_mode);
1231
1232                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1233
1234                         if (!dev->absinfo)
1235                                 return -EINVAL;
1236
1237                         t = _IOC_NR(cmd) & ABS_MAX;
1238                         abs = dev->absinfo[t];
1239
1240                         if (copy_to_user(p, &abs, min_t(size_t,
1241                                         size, sizeof(struct input_absinfo))))
1242                                 return -EFAULT;
1243
1244                         return 0;
1245                 }
1246         }
1247
1248         if (_IOC_DIR(cmd) == _IOC_WRITE) {
1249
1250                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1251
1252                         if (!dev->absinfo)
1253                                 return -EINVAL;
1254
1255                         t = _IOC_NR(cmd) & ABS_MAX;
1256
1257                         if (copy_from_user(&abs, p, min_t(size_t,
1258                                         size, sizeof(struct input_absinfo))))
1259                                 return -EFAULT;
1260
1261                         if (size < sizeof(struct input_absinfo))
1262                                 abs.resolution = 0;
1263
1264                         /* We can't change number of reserved MT slots */
1265                         if (t == ABS_MT_SLOT)
1266                                 return -EINVAL;
1267
1268                         /*
1269                          * Take event lock to ensure that we are not
1270                          * changing device parameters in the middle
1271                          * of event.
1272                          */
1273                         spin_lock_irq(&dev->event_lock);
1274                         dev->absinfo[t] = abs;
1275                         spin_unlock_irq(&dev->event_lock);
1276
1277                         return 0;
1278                 }
1279         }
1280
1281         return -EINVAL;
1282 }
1283
1284 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1285                                 void __user *p, int compat_mode)
1286 {
1287         struct evdev_client *client = file->private_data;
1288         struct evdev *evdev = client->evdev;
1289         int retval;
1290
1291         retval = mutex_lock_interruptible(&evdev->mutex);
1292         if (retval)
1293                 return retval;
1294
1295         if (!evdev->exist || client->revoked) {
1296                 retval = -ENODEV;
1297                 goto out;
1298         }
1299
1300         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1301
1302  out:
1303         mutex_unlock(&evdev->mutex);
1304         return retval;
1305 }
1306
1307 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1308 {
1309         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1310 }
1311
1312 #ifdef CONFIG_COMPAT
1313 static long evdev_ioctl_compat(struct file *file,
1314                                 unsigned int cmd, unsigned long arg)
1315 {
1316         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1317 }
1318 #endif
1319
1320 static const struct file_operations evdev_fops = {
1321         .owner          = THIS_MODULE,
1322         .read           = evdev_read,
1323         .write          = evdev_write,
1324         .poll           = evdev_poll,
1325         .open           = evdev_open,
1326         .release        = evdev_release,
1327         .unlocked_ioctl = evdev_ioctl,
1328 #ifdef CONFIG_COMPAT
1329         .compat_ioctl   = evdev_ioctl_compat,
1330 #endif
1331         .fasync         = evdev_fasync,
1332         .flush          = evdev_flush,
1333         .llseek         = no_llseek,
1334 };
1335
1336 /*
1337  * Mark device non-existent. This disables writes, ioctls and
1338  * prevents new users from opening the device. Already posted
1339  * blocking reads will stay, however new ones will fail.
1340  */
1341 static void evdev_mark_dead(struct evdev *evdev)
1342 {
1343         mutex_lock(&evdev->mutex);
1344         evdev->exist = false;
1345         mutex_unlock(&evdev->mutex);
1346 }
1347
1348 static void evdev_cleanup(struct evdev *evdev)
1349 {
1350         struct input_handle *handle = &evdev->handle;
1351
1352         evdev_mark_dead(evdev);
1353         evdev_hangup(evdev);
1354
1355         cdev_del(&evdev->cdev);
1356
1357         /* evdev is marked dead so no one else accesses evdev->open */
1358         if (evdev->open) {
1359                 input_flush_device(handle, NULL);
1360                 input_close_device(handle);
1361         }
1362 }
1363
1364 /*
1365  * Create new evdev device. Note that input core serializes calls
1366  * to connect and disconnect.
1367  */
1368 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1369                          const struct input_device_id *id)
1370 {
1371         struct evdev *evdev;
1372         int minor;
1373         int dev_no;
1374         int error;
1375
1376         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1377         if (minor < 0) {
1378                 error = minor;
1379                 pr_err("failed to reserve new minor: %d\n", error);
1380                 return error;
1381         }
1382
1383         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1384         if (!evdev) {
1385                 error = -ENOMEM;
1386                 goto err_free_minor;
1387         }
1388
1389         INIT_LIST_HEAD(&evdev->client_list);
1390         spin_lock_init(&evdev->client_lock);
1391         mutex_init(&evdev->mutex);
1392         init_waitqueue_head(&evdev->wait);
1393         evdev->exist = true;
1394
1395         dev_no = minor;
1396         /* Normalize device number if it falls into legacy range */
1397         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1398                 dev_no -= EVDEV_MINOR_BASE;
1399         dev_set_name(&evdev->dev, "event%d", dev_no);
1400
1401         evdev->handle.dev = input_get_device(dev);
1402         evdev->handle.name = dev_name(&evdev->dev);
1403         evdev->handle.handler = handler;
1404         evdev->handle.private = evdev;
1405
1406         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1407         evdev->dev.class = &input_class;
1408         evdev->dev.parent = &dev->dev;
1409         evdev->dev.release = evdev_free;
1410         device_initialize(&evdev->dev);
1411
1412         error = input_register_handle(&evdev->handle);
1413         if (error)
1414                 goto err_free_evdev;
1415
1416         cdev_init(&evdev->cdev, &evdev_fops);
1417         evdev->cdev.kobj.parent = &evdev->dev.kobj;
1418         error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1419         if (error)
1420                 goto err_unregister_handle;
1421
1422         error = device_add(&evdev->dev);
1423         if (error)
1424                 goto err_cleanup_evdev;
1425
1426         return 0;
1427
1428  err_cleanup_evdev:
1429         evdev_cleanup(evdev);
1430  err_unregister_handle:
1431         input_unregister_handle(&evdev->handle);
1432  err_free_evdev:
1433         put_device(&evdev->dev);
1434  err_free_minor:
1435         input_free_minor(minor);
1436         return error;
1437 }
1438
1439 static void evdev_disconnect(struct input_handle *handle)
1440 {
1441         struct evdev *evdev = handle->private;
1442
1443         device_del(&evdev->dev);
1444         evdev_cleanup(evdev);
1445         input_free_minor(MINOR(evdev->dev.devt));
1446         input_unregister_handle(handle);
1447         put_device(&evdev->dev);
1448 }
1449
1450 static const struct input_device_id evdev_ids[] = {
1451         { .driver_info = 1 },   /* Matches all devices */
1452         { },                    /* Terminating zero entry */
1453 };
1454
1455 MODULE_DEVICE_TABLE(input, evdev_ids);
1456
1457 static struct input_handler evdev_handler = {
1458         .event          = evdev_event,
1459         .events         = evdev_events,
1460         .connect        = evdev_connect,
1461         .disconnect     = evdev_disconnect,
1462         .legacy_minors  = true,
1463         .minor          = EVDEV_MINOR_BASE,
1464         .name           = "evdev",
1465         .id_table       = evdev_ids,
1466 };
1467
1468 static int __init evdev_init(void)
1469 {
1470         return input_register_handler(&evdev_handler);
1471 }
1472
1473 static void __exit evdev_exit(void)
1474 {
1475         input_unregister_handler(&evdev_handler);
1476 }
1477
1478 module_init(evdev_init);
1479 module_exit(evdev_exit);
1480
1481 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1482 MODULE_DESCRIPTION("Input driver event char devices");
1483 MODULE_LICENSE("GPL");