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