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] = *ev;
 139                 }
 140
 141                 num++;
 142                 head = (head + 1) & mask;
 143
 144                 if (is_report) {
 145                         num = 0;
 146                         client->packet_head = head;
 147                 }
 148         }
 149
 150         client->head = head;
 151 }
 152
 153 static void __evdev_queue_syn_dropped(struct evdev_client *client)
 154 {
 155         struct input_event ev;
 156         ktime_t time;
 157         struct timespec64 ts;
 158
 159         time = client->clk_type == EV_CLK_REAL ?
 160                         ktime_get_real() :
 161                         client->clk_type == EV_CLK_MONO ?
 162                                 ktime_get() :
 163                                 ktime_get_boottime();
 164
 165         ts = ktime_to_timespec64(time);
 166         ev.input_event_sec = ts.tv_sec;
 167         ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 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] = (struct input_event) {
 245                         .input_event_sec = event->input_event_sec,
 246                         .input_event_usec = event->input_event_usec,
 247                         .type = EV_SYN,
 248                         .code = SYN_DROPPED,
 249                         .value = 0,
 250                 };
 251
 252                 client->packet_head = client->tail;
 253         }
 254
 255         if (event->type == EV_SYN && event->code == SYN_REPORT) {
 256                 client->packet_head = client->head;
 257                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
 258         }
 259 }
 260
 261 static void evdev_pass_values(struct evdev_client *client,
 262                         const struct input_value *vals, unsigned int count,
 263                         ktime_t *ev_time)
 264 {
 265         struct evdev *evdev = client->evdev;
 266         const struct input_value *v;
 267         struct input_event event;
 268         struct timespec64 ts;
 269         bool wakeup = false;
 270
 271         if (client->revoked)
 272                 return;
 273
 274         ts = ktime_to_timespec64(ev_time[client->clk_type]);
 275         event.input_event_sec = ts.tv_sec;
 276         event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 277
 278         /* Interrupts are disabled, just acquire the lock. */
 279         spin_lock(&client->buffer_lock);
 280
 281         for (v = vals; v != vals + count; v++) {
 282                 if (__evdev_is_filtered(client, v->type, v->code))
 283                         continue;
 284
 285                 if (v->type == EV_SYN && v->code == SYN_REPORT) {
 286                         /* drop empty SYN_REPORT */
 287                         if (client->packet_head == client->head)
 288                                 continue;
 289
 290                         wakeup = true;
 291                 }
 292
 293                 event.type = v->type;
 294                 event.code = v->code;
 295                 event.value = v->value;
 296                 __pass_event(client, &event);
 297         }
 298
 299         spin_unlock(&client->buffer_lock);
 300
 301         if (wakeup)
 302                 wake_up_interruptible(&evdev->wait);
 303 }
 304
 305 /*
 306  * Pass incoming events to all connected clients.
 307  */
 308 static void evdev_events(struct input_handle *handle,
 309                          const struct input_value *vals, unsigned int count)
 310 {
 311         struct evdev *evdev = handle->private;
 312         struct evdev_client *client;
 313         ktime_t ev_time[EV_CLK_MAX];
 314
 315         ev_time[EV_CLK_MONO] = ktime_get();
 316         ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
 317         ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
 318                                                  TK_OFFS_BOOT);
 319
 320         rcu_read_lock();
 321
 322         client = rcu_dereference(evdev->grab);
 323
 324         if (client)
 325                 evdev_pass_values(client, vals, count, ev_time);
 326         else
 327                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 328                         evdev_pass_values(client, vals, count, ev_time);
 329
 330         rcu_read_unlock();
 331 }
 332
 333 /*
 334  * Pass incoming event to all connected clients.
 335  */
 336 static void evdev_event(struct input_handle *handle,
 337                         unsigned int type, unsigned int code, int value)
 338 {
 339         struct input_value vals[] = { { type, code, value } };
 340
 341         evdev_events(handle, vals, 1);
 342 }
 343
 344 static int evdev_fasync(int fd, struct file *file, int on)
 345 {
 346         struct evdev_client *client = file->private_data;
 347
 348         return fasync_helper(fd, file, on, &client->fasync);
 349 }
 350
 351 static void evdev_free(struct device *dev)
 352 {
 353         struct evdev *evdev = container_of(dev, struct evdev, dev);
 354
 355         input_put_device(evdev->handle.dev);
 356         kfree(evdev);
 357 }
 358
 359 /*
 360  * Grabs an event device (along with underlying input device).
 361  * This function is called with evdev->mutex taken.
 362  */
 363 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 364 {
 365         int error;
 366
 367         if (evdev->grab)
 368                 return -EBUSY;
 369
 370         error = input_grab_device(&evdev->handle);
 371         if (error)
 372                 return error;
 373
 374         rcu_assign_pointer(evdev->grab, client);
 375
 376         return 0;
 377 }
 378
 379 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 380 {
 381         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 382                                         lockdep_is_held(&evdev->mutex));
 383
 384         if (grab != client)
 385                 return  -EINVAL;
 386
 387         rcu_assign_pointer(evdev->grab, NULL);
 388         synchronize_rcu();
 389         input_release_device(&evdev->handle);
 390
 391         return 0;
 392 }
 393
 394 static void evdev_attach_client(struct evdev *evdev,
 395                                 struct evdev_client *client)
 396 {
 397         spin_lock(&evdev->client_lock);
 398         list_add_tail_rcu(&client->node, &evdev->client_list);
 399         spin_unlock(&evdev->client_lock);
 400 }
 401
 402 static void evdev_detach_client(struct evdev *evdev,
 403                                 struct evdev_client *client)
 404 {
 405         spin_lock(&evdev->client_lock);
 406         list_del_rcu(&client->node);
 407         spin_unlock(&evdev->client_lock);
 408         synchronize_rcu();
 409 }
 410
 411 static int evdev_open_device(struct evdev *evdev)
 412 {
 413         int retval;
 414
 415         retval = mutex_lock_interruptible(&evdev->mutex);
 416         if (retval)
 417                 return retval;
 418
 419         if (!evdev->exist)
 420                 retval = -ENODEV;
 421         else if (!evdev->open++) {
 422                 retval = input_open_device(&evdev->handle);
 423                 if (retval)
 424                         evdev->open--;
 425         }
 426
 427         mutex_unlock(&evdev->mutex);
 428         return retval;
 429 }
 430
 431 static void evdev_close_device(struct evdev *evdev)
 432 {
 433         mutex_lock(&evdev->mutex);
 434
 435         if (evdev->exist && !--evdev->open)
 436                 input_close_device(&evdev->handle);
 437
 438         mutex_unlock(&evdev->mutex);
 439 }
 440
 441 /*
 442  * Wake up users waiting for IO so they can disconnect from
 443  * dead device.
 444  */
 445 static void evdev_hangup(struct evdev *evdev)
 446 {
 447         struct evdev_client *client;
 448
 449         spin_lock(&evdev->client_lock);
 450         list_for_each_entry(client, &evdev->client_list, node)
 451                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 452         spin_unlock(&evdev->client_lock);
 453
 454         wake_up_interruptible(&evdev->wait);
 455 }
 456
 457 static int evdev_release(struct inode *inode, struct file *file)
 458 {
 459         struct evdev_client *client = file->private_data;
 460         struct evdev *evdev = client->evdev;
 461         unsigned int i;
 462
 463         mutex_lock(&evdev->mutex);
 464
 465         if (evdev->exist && !client->revoked)
 466                 input_flush_device(&evdev->handle, file);
 467
 468         evdev_ungrab(evdev, client);
 469         mutex_unlock(&evdev->mutex);
 470
 471         evdev_detach_client(evdev, client);
 472
 473         for (i = 0; i < EV_CNT; ++i)
 474                 bitmap_free(client->evmasks[i]);
 475
 476         kvfree(client);
 477
 478         evdev_close_device(evdev);
 479
 480         return 0;
 481 }
 482
 483 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 484 {
 485         unsigned int n_events =
 486                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 487                     EVDEV_MIN_BUFFER_SIZE);
 488
 489         return roundup_pow_of_two(n_events);
 490 }
 491
 492 static int evdev_open(struct inode *inode, struct file *file)
 493 {
 494         struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
 495         unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 496         unsigned int size = sizeof(struct evdev_client) +
 497                                         bufsize * sizeof(struct input_event);
 498         struct evdev_client *client;
 499         int error;
 500
 501         client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
 502         if (!client)
 503                 client = vzalloc(size);
 504         if (!client)
 505                 return -ENOMEM;
 506
 507         client->bufsize = bufsize;
 508         spin_lock_init(&client->buffer_lock);
 509         client->evdev = evdev;
 510         evdev_attach_client(evdev, client);
 511
 512         error = evdev_open_device(evdev);
 513         if (error)
 514                 goto err_free_client;
 515
 516         file->private_data = client;
 517         nonseekable_open(inode, file);
 518
 519         return 0;
 520
 521  err_free_client:
 522         evdev_detach_client(evdev, client);
 523         kvfree(client);
 524         return error;
 525 }
 526
 527 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 528                            size_t count, loff_t *ppos)
 529 {
 530         struct evdev_client *client = file->private_data;
 531         struct evdev *evdev = client->evdev;
 532         struct input_event event;
 533         int retval = 0;
 534
 535         if (count != 0 && count < input_event_size())
 536                 return -EINVAL;
 537
 538         retval = mutex_lock_interruptible(&evdev->mutex);
 539         if (retval)
 540                 return retval;
 541
 542         if (!evdev->exist || client->revoked) {
 543                 retval = -ENODEV;
 544                 goto out;
 545         }
 546
 547         while (retval + input_event_size() <= count) {
 548
 549                 if (input_event_from_user(buffer + retval, &event)) {
 550                         retval = -EFAULT;
 551                         goto out;
 552                 }
 553                 retval += input_event_size();
 554
 555                 input_inject_event(&evdev->handle,
 556                                    event.type, event.code, event.value);
 557                 cond_resched();
 558         }
 559
 560  out:
 561         mutex_unlock(&evdev->mutex);
 562         return retval;
 563 }
 564
 565 static int evdev_fetch_next_event(struct evdev_client *client,
 566                                   struct input_event *event)
 567 {
 568         int have_event;
 569
 570         spin_lock_irq(&client->buffer_lock);
 571
 572         have_event = client->packet_head != client->tail;
 573         if (have_event) {
 574                 *event = client->buffer[client->tail++];
 575                 client->tail &= client->bufsize - 1;
 576         }
 577
 578         spin_unlock_irq(&client->buffer_lock);
 579
 580         return have_event;
 581 }
 582
 583 static ssize_t evdev_read(struct file *file, char __user *buffer,
 584                           size_t count, loff_t *ppos)
 585 {
 586         struct evdev_client *client = file->private_data;
 587         struct evdev *evdev = client->evdev;
 588         struct input_event event;
 589         size_t read = 0;
 590         int error;
 591
 592         if (count != 0 && count < input_event_size())
 593                 return -EINVAL;
 594
 595         for (;;) {
 596                 if (!evdev->exist || client->revoked)
 597                         return -ENODEV;
 598
 599                 if (client->packet_head == client->tail &&
 600                     (file->f_flags & O_NONBLOCK))
 601                         return -EAGAIN;
 602
 603                 /*
 604                  * count == 0 is special - no IO is done but we check
 605                  * for error conditions (see above).
 606                  */
 607                 if (count == 0)
 608                         break;
 609
 610                 while (read + input_event_size() <= count &&
 611                        evdev_fetch_next_event(client, &event)) {
 612
 613                         if (input_event_to_user(buffer + read, &event))
 614                                 return -EFAULT;
 615
 616                         read += input_event_size();
 617                 }
 618
 619                 if (read)
 620                         break;
 621
 622                 if (!(file->f_flags & O_NONBLOCK)) {
 623                         error = wait_event_interruptible(evdev->wait,
 624                                         client->packet_head != client->tail ||
 625                                         !evdev->exist || client->revoked);
 626                         if (error)
 627                                 return error;
 628                 }
 629         }
 630
 631         return read;
 632 }
 633
 634 /* No kernel lock - fine */
 635 static __poll_t evdev_poll(struct file *file, poll_table *wait)
 636 {
 637         struct evdev_client *client = file->private_data;
 638         struct evdev *evdev = client->evdev;
 639         __poll_t mask;
 640
 641         poll_wait(file, &evdev->wait, wait);
 642
 643         if (evdev->exist && !client->revoked)
 644                 mask = EPOLLOUT | EPOLLWRNORM;
 645         else
 646                 mask = EPOLLHUP | EPOLLERR;
 647
 648         if (client->packet_head != client->tail)
 649                 mask |= EPOLLIN | EPOLLRDNORM;
 650
 651         return mask;
 652 }
 653
 654 #ifdef CONFIG_COMPAT
 655
 656 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 657 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 658
 659 #ifdef __BIG_ENDIAN
 660 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 661                         unsigned int maxlen, void __user *p, int compat)
 662 {
 663         int len, i;
 664
 665         if (compat) {
 666                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 667                 if (len > maxlen)
 668                         len = maxlen;
 669
 670                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 671                         if (copy_to_user((compat_long_t __user *) p + i,
 672                                          (compat_long_t *) bits +
 673                                                 i + 1 - ((i % 2) << 1),
 674                                          sizeof(compat_long_t)))
 675                                 return -EFAULT;
 676         } else {
 677                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 678                 if (len > maxlen)
 679                         len = maxlen;
 680
 681                 if (copy_to_user(p, bits, len))
 682                         return -EFAULT;
 683         }
 684
 685         return len;
 686 }
 687
 688 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 689                           unsigned int maxlen, const void __user *p, int compat)
 690 {
 691         int len, i;
 692
 693         if (compat) {
 694                 if (maxlen % sizeof(compat_long_t))
 695                         return -EINVAL;
 696
 697                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 698                 if (len > maxlen)
 699                         len = maxlen;
 700
 701                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 702                         if (copy_from_user((compat_long_t *) bits +
 703                                                 i + 1 - ((i % 2) << 1),
 704                                            (compat_long_t __user *) p + i,
 705                                            sizeof(compat_long_t)))
 706                                 return -EFAULT;
 707                 if (i % 2)
 708                         *((compat_long_t *) bits + i - 1) = 0;
 709
 710         } else {
 711                 if (maxlen % sizeof(long))
 712                         return -EINVAL;
 713
 714                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 715                 if (len > maxlen)
 716                         len = maxlen;
 717
 718                 if (copy_from_user(bits, p, len))
 719                         return -EFAULT;
 720         }
 721
 722         return len;
 723 }
 724
 725 #else
 726
 727 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 728                         unsigned int maxlen, void __user *p, int compat)
 729 {
 730         int len = compat ?
 731                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 732                         BITS_TO_LONGS(maxbit) * sizeof(long);
 733
 734         if (len > maxlen)
 735                 len = maxlen;
 736
 737         return copy_to_user(p, bits, len) ? -EFAULT : len;
 738 }
 739
 740 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 741                           unsigned int maxlen, const void __user *p, int compat)
 742 {
 743         size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
 744         int len;
 745
 746         if (maxlen % chunk_size)
 747                 return -EINVAL;
 748
 749         len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
 750         len *= chunk_size;
 751         if (len > maxlen)
 752                 len = maxlen;
 753
 754         return copy_from_user(bits, p, len) ? -EFAULT : len;
 755 }
 756
 757 #endif /* __BIG_ENDIAN */
 758
 759 #else
 760
 761 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 762                         unsigned int maxlen, void __user *p, int compat)
 763 {
 764         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 765
 766         if (len > maxlen)
 767                 len = maxlen;
 768
 769         return copy_to_user(p, bits, len) ? -EFAULT : len;
 770 }
 771
 772 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 773                           unsigned int maxlen, const void __user *p, int compat)
 774 {
 775         int len;
 776
 777         if (maxlen % sizeof(long))
 778                 return -EINVAL;
 779
 780         len = BITS_TO_LONGS(maxbit) * sizeof(long);
 781         if (len > maxlen)
 782                 len = maxlen;
 783
 784         return copy_from_user(bits, p, len) ? -EFAULT : len;
 785 }
 786
 787 #endif /* CONFIG_COMPAT */
 788
 789 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 790 {
 791         int len;
 792
 793         if (!str)
 794                 return -ENOENT;
 795
 796         len = strlen(str) + 1;
 797         if (len > maxlen)
 798                 len = maxlen;
 799
 800         return copy_to_user(p, str, len) ? -EFAULT : len;
 801 }
 802
 803 static int handle_eviocgbit(struct input_dev *dev,
 804                             unsigned int type, unsigned int size,
 805                             void __user *p, int compat_mode)
 806 {
 807         unsigned long *bits;
 808         int len;
 809
 810         switch (type) {
 811
 812         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 813         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 814         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 815         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 816         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 817         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 818         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 819         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 820         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 821         default: return -EINVAL;
 822         }
 823
 824         return bits_to_user(bits, len, size, p, compat_mode);
 825 }
 826
 827 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 828 {
 829         struct input_keymap_entry ke = {
 830                 .len    = sizeof(unsigned int),
 831                 .flags  = 0,
 832         };
 833         int __user *ip = (int __user *)p;
 834         int error;
 835
 836         /* legacy case */
 837         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 838                 return -EFAULT;
 839
 840         error = input_get_keycode(dev, &ke);
 841         if (error)
 842                 return error;
 843
 844         if (put_user(ke.keycode, ip + 1))
 845                 return -EFAULT;
 846
 847         return 0;
 848 }
 849
 850 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 851 {
 852         struct input_keymap_entry ke;
 853         int error;
 854
 855         if (copy_from_user(&ke, p, sizeof(ke)))
 856                 return -EFAULT;
 857
 858         error = input_get_keycode(dev, &ke);
 859         if (error)
 860                 return error;
 861
 862         if (copy_to_user(p, &ke, sizeof(ke)))
 863                 return -EFAULT;
 864
 865         return 0;
 866 }
 867
 868 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 869 {
 870         struct input_keymap_entry ke = {
 871                 .len    = sizeof(unsigned int),
 872                 .flags  = 0,
 873         };
 874         int __user *ip = (int __user *)p;
 875
 876         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 877                 return -EFAULT;
 878
 879         if (get_user(ke.keycode, ip + 1))
 880                 return -EFAULT;
 881
 882         return input_set_keycode(dev, &ke);
 883 }
 884
 885 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 886 {
 887         struct input_keymap_entry ke;
 888
 889         if (copy_from_user(&ke, p, sizeof(ke)))
 890                 return -EFAULT;
 891
 892         if (ke.len > sizeof(ke.scancode))
 893                 return -EINVAL;
 894
 895         return input_set_keycode(dev, &ke);
 896 }
 897
 898 /*
 899  * If we transfer state to the user, we should flush all pending events
 900  * of the same type from the client's queue. Otherwise, they might end up
 901  * with duplicate events, which can screw up client's state tracking.
 902  * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
 903  * event so user-space will notice missing events.
 904  *
 905  * LOCKING:
 906  * We need to take event_lock before buffer_lock to avoid dead-locks. But we
 907  * need the even_lock only to guarantee consistent state. We can safely release
 908  * it while flushing the queue. This allows input-core to handle filters while
 909  * we flush the queue.
 910  */
 911 static int evdev_handle_get_val(struct evdev_client *client,
 912                                 struct input_dev *dev, unsigned int type,
 913                                 unsigned long *bits, unsigned int maxbit,
 914                                 unsigned int maxlen, void __user *p,
 915                                 int compat)
 916 {
 917         int ret;
 918         unsigned long *mem;
 919
 920         mem = bitmap_alloc(maxbit, GFP_KERNEL);
 921         if (!mem)
 922                 return -ENOMEM;
 923
 924         spin_lock_irq(&dev->event_lock);
 925         spin_lock(&client->buffer_lock);
 926
 927         bitmap_copy(mem, bits, maxbit);
 928
 929         spin_unlock(&dev->event_lock);
 930
 931         __evdev_flush_queue(client, type);
 932
 933         spin_unlock_irq(&client->buffer_lock);
 934
 935         ret = bits_to_user(mem, maxbit, maxlen, p, compat);
 936         if (ret < 0)
 937                 evdev_queue_syn_dropped(client);
 938
 939         bitmap_free(mem);
 940
 941         return ret;
 942 }
 943
 944 static int evdev_handle_mt_request(struct input_dev *dev,
 945                                    unsigned int size,
 946                                    int __user *ip)
 947 {
 948         const struct input_mt *mt = dev->mt;
 949         unsigned int code;
 950         int max_slots;
 951         int i;
 952
 953         if (get_user(code, &ip[0]))
 954                 return -EFAULT;
 955         if (!mt || !input_is_mt_value(code))
 956                 return -EINVAL;
 957
 958         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 959         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 960                 int value = input_mt_get_value(&mt->slots[i], code);
 961                 if (put_user(value, &ip[1 + i]))
 962                         return -EFAULT;
 963         }
 964
 965         return 0;
 966 }
 967
 968 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
 969                         struct file *file)
 970 {
 971         client->revoked = true;
 972         evdev_ungrab(evdev, client);
 973         input_flush_device(&evdev->handle, file);
 974         wake_up_interruptible(&evdev->wait);
 975
 976         return 0;
 977 }
 978
 979 /* must be called with evdev-mutex held */
 980 static int evdev_set_mask(struct evdev_client *client,
 981                           unsigned int type,
 982                           const void __user *codes,
 983                           u32 codes_size,
 984                           int compat)
 985 {
 986         unsigned long flags, *mask, *oldmask;
 987         size_t cnt;
 988         int error;
 989
 990         /* we allow unknown types and 'codes_size > size' for forward-compat */
 991         cnt = evdev_get_mask_cnt(type);
 992         if (!cnt)
 993                 return 0;
 994
 995         mask = bitmap_zalloc(cnt, GFP_KERNEL);
 996         if (!mask)
 997                 return -ENOMEM;
 998
 999         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1000         if (error < 0) {
1001                 bitmap_free(mask);
1002                 return error;
1003         }
1004
1005         spin_lock_irqsave(&client->buffer_lock, flags);
1006         oldmask = client->evmasks[type];
1007         client->evmasks[type] = mask;
1008         spin_unlock_irqrestore(&client->buffer_lock, flags);
1009
1010         bitmap_free(oldmask);
1011
1012         return 0;
1013 }
1014
1015 /* must be called with evdev-mutex held */
1016 static int evdev_get_mask(struct evdev_client *client,
1017                           unsigned int type,
1018                           void __user *codes,
1019                           u32 codes_size,
1020                           int compat)
1021 {
1022         unsigned long *mask;
1023         size_t cnt, size, xfer_size;
1024         int i;
1025         int error;
1026
1027         /* we allow unknown types and 'codes_size > size' for forward-compat */
1028         cnt = evdev_get_mask_cnt(type);
1029         size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1030         xfer_size = min_t(size_t, codes_size, size);
1031
1032         if (cnt > 0) {
1033                 mask = client->evmasks[type];
1034                 if (mask) {
1035                         error = bits_to_user(mask, cnt - 1,
1036                                              xfer_size, codes, compat);
1037                         if (error < 0)
1038                                 return error;
1039                 } else {
1040                         /* fake mask with all bits set */
1041                         for (i = 0; i < xfer_size; i++)
1042                                 if (put_user(0xffU, (u8 __user *)codes + i))
1043                                         return -EFAULT;
1044                 }
1045         }
1046
1047         if (xfer_size < codes_size)
1048                 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1049                         return -EFAULT;
1050
1051         return 0;
1052 }
1053
1054 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1055                            void __user *p, int compat_mode)
1056 {
1057         struct evdev_client *client = file->private_data;
1058         struct evdev *evdev = client->evdev;
1059         struct input_dev *dev = evdev->handle.dev;
1060         struct input_absinfo abs;
1061         struct input_mask mask;
1062         struct ff_effect effect;
1063         int __user *ip = (int __user *)p;
1064         unsigned int i, t, u, v;
1065         unsigned int size;
1066         int error;
1067
1068         /* First we check for fixed-length commands */
1069         switch (cmd) {
1070
1071         case EVIOCGVERSION:
1072                 return put_user(EV_VERSION, ip);
1073
1074         case EVIOCGID:
1075                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1076                         return -EFAULT;
1077                 return 0;
1078
1079         case EVIOCGREP:
1080                 if (!test_bit(EV_REP, dev->evbit))
1081                         return -ENOSYS;
1082                 if (put_user(dev->rep[REP_DELAY], ip))
1083                         return -EFAULT;
1084                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1085                         return -EFAULT;
1086                 return 0;
1087
1088         case EVIOCSREP:
1089                 if (!test_bit(EV_REP, dev->evbit))
1090                         return -ENOSYS;
1091                 if (get_user(u, ip))
1092                         return -EFAULT;
1093                 if (get_user(v, ip + 1))
1094                         return -EFAULT;
1095
1096                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1097                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1098
1099                 return 0;
1100
1101         case EVIOCRMFF:
1102                 return input_ff_erase(dev, (int)(unsigned long) p, file);
1103
1104         case EVIOCGEFFECTS:
1105                 i = test_bit(EV_FF, dev->evbit) ?
1106                                 dev->ff->max_effects : 0;
1107                 if (put_user(i, ip))
1108                         return -EFAULT;
1109                 return 0;
1110
1111         case EVIOCGRAB:
1112                 if (p)
1113                         return evdev_grab(evdev, client);
1114                 else
1115                         return evdev_ungrab(evdev, client);
1116
1117         case EVIOCREVOKE:
1118                 if (p)
1119                         return -EINVAL;
1120                 else
1121                         return evdev_revoke(evdev, client, file);
1122
1123         case EVIOCGMASK: {
1124                 void __user *codes_ptr;
1125
1126                 if (copy_from_user(&mask, p, sizeof(mask)))
1127                         return -EFAULT;
1128
1129                 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1130                 return evdev_get_mask(client,
1131                                       mask.type, codes_ptr, mask.codes_size,
1132                                       compat_mode);
1133         }
1134
1135         case EVIOCSMASK: {
1136                 const void __user *codes_ptr;
1137
1138                 if (copy_from_user(&mask, p, sizeof(mask)))
1139                         return -EFAULT;
1140
1141                 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1142                 return evdev_set_mask(client,
1143                                       mask.type, codes_ptr, mask.codes_size,
1144                                       compat_mode);
1145         }
1146
1147         case EVIOCSCLOCKID:
1148                 if (copy_from_user(&i, p, sizeof(unsigned int)))
1149                         return -EFAULT;
1150
1151                 return evdev_set_clk_type(client, i);
1152
1153         case EVIOCGKEYCODE:
1154                 return evdev_handle_get_keycode(dev, p);
1155
1156         case EVIOCSKEYCODE:
1157                 return evdev_handle_set_keycode(dev, p);
1158
1159         case EVIOCGKEYCODE_V2:
1160                 return evdev_handle_get_keycode_v2(dev, p);
1161
1162         case EVIOCSKEYCODE_V2:
1163                 return evdev_handle_set_keycode_v2(dev, p);
1164         }
1165
1166         size = _IOC_SIZE(cmd);
1167
1168         /* Now check variable-length commands */
1169 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1170         switch (EVIOC_MASK_SIZE(cmd)) {
1171
1172         case EVIOCGPROP(0):
1173                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1174                                     size, p, compat_mode);
1175
1176         case EVIOCGMTSLOTS(0):
1177                 return evdev_handle_mt_request(dev, size, ip);
1178
1179         case EVIOCGKEY(0):
1180                 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1181                                             KEY_MAX, size, p, compat_mode);
1182
1183         case EVIOCGLED(0):
1184                 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1185                                             LED_MAX, size, p, compat_mode);
1186
1187         case EVIOCGSND(0):
1188                 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1189                                             SND_MAX, size, p, compat_mode);
1190
1191         case EVIOCGSW(0):
1192                 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1193                                             SW_MAX, size, p, compat_mode);
1194
1195         case EVIOCGNAME(0):
1196                 return str_to_user(dev->name, size, p);
1197
1198         case EVIOCGPHYS(0):
1199                 return str_to_user(dev->phys, size, p);
1200
1201         case EVIOCGUNIQ(0):
1202                 return str_to_user(dev->uniq, size, p);
1203
1204         case EVIOC_MASK_SIZE(EVIOCSFF):
1205                 if (input_ff_effect_from_user(p, size, &effect))
1206                         return -EFAULT;
1207
1208                 error = input_ff_upload(dev, &effect, file);
1209                 if (error)
1210                         return error;
1211
1212                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1213                         return -EFAULT;
1214
1215                 return 0;
1216         }
1217
1218         /* Multi-number variable-length handlers */
1219         if (_IOC_TYPE(cmd) != 'E')
1220                 return -EINVAL;
1221
1222         if (_IOC_DIR(cmd) == _IOC_READ) {
1223
1224                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1225                         return handle_eviocgbit(dev,
1226                                                 _IOC_NR(cmd) & EV_MAX, size,
1227                                                 p, compat_mode);
1228
1229                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1230
1231                         if (!dev->absinfo)
1232                                 return -EINVAL;
1233
1234                         t = _IOC_NR(cmd) & ABS_MAX;
1235                         abs = dev->absinfo[t];
1236
1237                         if (copy_to_user(p, &abs, min_t(size_t,
1238                                         size, sizeof(struct input_absinfo))))
1239                                 return -EFAULT;
1240
1241                         return 0;
1242                 }
1243         }
1244
1245         if (_IOC_DIR(cmd) == _IOC_WRITE) {
1246
1247                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1248
1249                         if (!dev->absinfo)
1250                                 return -EINVAL;
1251
1252                         t = _IOC_NR(cmd) & ABS_MAX;
1253
1254                         if (copy_from_user(&abs, p, min_t(size_t,
1255                                         size, sizeof(struct input_absinfo))))
1256                                 return -EFAULT;
1257
1258                         if (size < sizeof(struct input_absinfo))
1259                                 abs.resolution = 0;
1260
1261                         /* We can't change number of reserved MT slots */
1262                         if (t == ABS_MT_SLOT)
1263                                 return -EINVAL;
1264
1265                         /*
1266                          * Take event lock to ensure that we are not
1267                          * changing device parameters in the middle
1268                          * of event.
1269                          */
1270                         spin_lock_irq(&dev->event_lock);
1271                         dev->absinfo[t] = abs;
1272                         spin_unlock_irq(&dev->event_lock);
1273
1274                         return 0;
1275                 }
1276         }
1277
1278         return -EINVAL;
1279 }
1280
1281 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1282                                 void __user *p, int compat_mode)
1283 {
1284         struct evdev_client *client = file->private_data;
1285         struct evdev *evdev = client->evdev;
1286         int retval;
1287
1288         retval = mutex_lock_interruptible(&evdev->mutex);
1289         if (retval)
1290                 return retval;
1291
1292         if (!evdev->exist || client->revoked) {
1293                 retval = -ENODEV;
1294                 goto out;
1295         }
1296
1297         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1298
1299  out:
1300         mutex_unlock(&evdev->mutex);
1301         return retval;
1302 }
1303
1304 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1305 {
1306         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1307 }
1308
1309 #ifdef CONFIG_COMPAT
1310 static long evdev_ioctl_compat(struct file *file,
1311                                 unsigned int cmd, unsigned long arg)
1312 {
1313         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1314 }
1315 #endif
1316
1317 static const struct file_operations evdev_fops = {
1318         .owner          = THIS_MODULE,
1319         .read           = evdev_read,
1320         .write          = evdev_write,
1321         .poll           = evdev_poll,
1322         .open           = evdev_open,
1323         .release        = evdev_release,
1324         .unlocked_ioctl = evdev_ioctl,
1325 #ifdef CONFIG_COMPAT
1326         .compat_ioctl   = evdev_ioctl_compat,
1327 #endif
1328         .fasync         = evdev_fasync,
1329         .llseek         = no_llseek,
1330 };
1331
1332 /*
1333  * Mark device non-existent. This disables writes, ioctls and
1334  * prevents new users from opening the device. Already posted
1335  * blocking reads will stay, however new ones will fail.
1336  */
1337 static void evdev_mark_dead(struct evdev *evdev)
1338 {
1339         mutex_lock(&evdev->mutex);
1340         evdev->exist = false;
1341         mutex_unlock(&evdev->mutex);
1342 }
1343
1344 static void evdev_cleanup(struct evdev *evdev)
1345 {
1346         struct input_handle *handle = &evdev->handle;
1347
1348         evdev_mark_dead(evdev);
1349         evdev_hangup(evdev);
1350
1351         /* evdev is marked dead so no one else accesses evdev->open */
1352         if (evdev->open) {
1353                 input_flush_device(handle, NULL);
1354                 input_close_device(handle);
1355         }
1356 }
1357
1358 /*
1359  * Create new evdev device. Note that input core serializes calls
1360  * to connect and disconnect.
1361  */
1362 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1363                          const struct input_device_id *id)
1364 {
1365         struct evdev *evdev;
1366         int minor;
1367         int dev_no;
1368         int error;
1369
1370         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1371         if (minor < 0) {
1372                 error = minor;
1373                 pr_err("failed to reserve new minor: %d\n", error);
1374                 return error;
1375         }
1376
1377         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1378         if (!evdev) {
1379                 error = -ENOMEM;
1380                 goto err_free_minor;
1381         }
1382
1383         INIT_LIST_HEAD(&evdev->client_list);
1384         spin_lock_init(&evdev->client_lock);
1385         mutex_init(&evdev->mutex);
1386         init_waitqueue_head(&evdev->wait);
1387         evdev->exist = true;
1388
1389         dev_no = minor;
1390         /* Normalize device number if it falls into legacy range */
1391         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1392                 dev_no -= EVDEV_MINOR_BASE;
1393         dev_set_name(&evdev->dev, "event%d", dev_no);
1394
1395         evdev->handle.dev = input_get_device(dev);
1396         evdev->handle.name = dev_name(&evdev->dev);
1397         evdev->handle.handler = handler;
1398         evdev->handle.private = evdev;
1399
1400         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1401         evdev->dev.class = &input_class;
1402         evdev->dev.parent = &dev->dev;
1403         evdev->dev.release = evdev_free;
1404         device_initialize(&evdev->dev);
1405
1406         error = input_register_handle(&evdev->handle);
1407         if (error)
1408                 goto err_free_evdev;
1409
1410         cdev_init(&evdev->cdev, &evdev_fops);
1411
1412         error = cdev_device_add(&evdev->cdev, &evdev->dev);
1413         if (error)
1414                 goto err_cleanup_evdev;
1415
1416         return 0;
1417
1418  err_cleanup_evdev:
1419         evdev_cleanup(evdev);
1420         input_unregister_handle(&evdev->handle);
1421  err_free_evdev:
1422         put_device(&evdev->dev);
1423  err_free_minor:
1424         input_free_minor(minor);
1425         return error;
1426 }
1427
1428 static void evdev_disconnect(struct input_handle *handle)
1429 {
1430         struct evdev *evdev = handle->private;
1431
1432         cdev_device_del(&evdev->cdev, &evdev->dev);
1433         evdev_cleanup(evdev);
1434         input_free_minor(MINOR(evdev->dev.devt));
1435         input_unregister_handle(handle);
1436         put_device(&evdev->dev);
1437 }
1438
1439 static const struct input_device_id evdev_ids[] = {
1440         { .driver_info = 1 },   /* Matches all devices */
1441         { },                    /* Terminating zero entry */
1442 };
1443
1444 MODULE_DEVICE_TABLE(input, evdev_ids);
1445
1446 static struct input_handler evdev_handler = {
1447         .event          = evdev_event,
1448         .events         = evdev_events,
1449         .connect        = evdev_connect,
1450         .disconnect     = evdev_disconnect,
1451         .legacy_minors  = true,
1452         .minor          = EVDEV_MINOR_BASE,
1453         .name           = "evdev",
1454         .id_table       = evdev_ids,
1455 };
1456
1457 static int __init evdev_init(void)
1458 {
1459         return input_register_handler(&evdev_handler);
1460 }
1461
1462 static void __exit evdev_exit(void)
1463 {
1464         input_unregister_handler(&evdev_handler);
1465 }
1466
1467 module_init(evdev_init);
1468 module_exit(evdev_exit);
1469
1470 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1471 MODULE_DESCRIPTION("Input driver event char devices");
1472 MODULE_LICENSE("GPL");