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_MAX
  35 };
  36
  37 struct evdev {
  38         int open;
  39         struct input_handle handle;
  40         wait_queue_head_t wait;
  41         struct evdev_client __rcu *grab;
  42         struct list_head client_list;
  43         spinlock_t client_lock; /* protects client_list */
  44         struct mutex mutex;
  45         struct device dev;
  46         struct cdev cdev;
  47         bool exist;
  48 };
  49
  50 struct evdev_client {
  51         unsigned int head;
  52         unsigned int tail;
  53         unsigned int packet_head; /* [future] position of the first element of next packet */
  54         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  55         struct fasync_struct *fasync;
  56         struct evdev *evdev;
  57         struct list_head node;
  58         unsigned int clk_type;
  59         bool revoked;
  60         unsigned long *evmasks[EV_CNT];
  61         unsigned int bufsize;
  62         struct input_event buffer[];
  63 };
  64
  65 static size_t evdev_get_mask_cnt(unsigned int type)
  66 {
  67         static const size_t counts[EV_CNT] = {
  68                 /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
  69                 [EV_SYN]        = EV_CNT,
  70                 [EV_KEY]        = KEY_CNT,
  71                 [EV_REL]        = REL_CNT,
  72                 [EV_ABS]        = ABS_CNT,
  73                 [EV_MSC]        = MSC_CNT,
  74                 [EV_SW]         = SW_CNT,
  75                 [EV_LED]        = LED_CNT,
  76                 [EV_SND]        = SND_CNT,
  77                 [EV_FF]         = FF_CNT,
  78         };
  79
  80         return (type < EV_CNT) ? counts[type] : 0;
  81 }
  82
  83 /* requires the buffer lock to be held */
  84 static bool __evdev_is_filtered(struct evdev_client *client,
  85                                 unsigned int type,
  86                                 unsigned int code)
  87 {
  88         unsigned long *mask;
  89         size_t cnt;
  90
  91         /* EV_SYN and unknown codes are never filtered */
  92         if (type == EV_SYN || type >= EV_CNT)
  93                 return false;
  94
  95         /* first test whether the type is filtered */
  96         mask = client->evmasks[0];
  97         if (mask && !test_bit(type, mask))
  98                 return true;
  99
 100         /* unknown values are never filtered */
 101         cnt = evdev_get_mask_cnt(type);
 102         if (!cnt || code >= cnt)
 103                 return false;
 104
 105         mask = client->evmasks[type];
 106         return mask && !test_bit(code, mask);
 107 }
 108
 109 /* flush queued events of type @type, caller must hold client->buffer_lock */
 110 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
 111 {
 112         unsigned int i, head, num;
 113         unsigned int mask = client->bufsize - 1;
 114         bool is_report;
 115         struct input_event *ev;
 116
 117         BUG_ON(type == EV_SYN);
 118
 119         head = client->tail;
 120         client->packet_head = client->tail;
 121
 122         /* init to 1 so a leading SYN_REPORT will not be dropped */
 123         num = 1;
 124
 125         for (i = client->tail; i != client->head; i = (i + 1) & mask) {
 126                 ev = &client->buffer[i];
 127                 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
 128
 129                 if (ev->type == type) {
 130                         /* drop matched entry */
 131                         continue;
 132                 } else if (is_report && !num) {
 133                         /* drop empty SYN_REPORT groups */
 134                         continue;
 135                 } else if (head != i) {
 136                         /* move entry to fill the gap */
 137                         client->buffer[head] = *ev;
 138                 }
 139
 140                 num++;
 141                 head = (head + 1) & mask;
 142
 143                 if (is_report) {
 144                         num = 0;
 145                         client->packet_head = head;
 146                 }
 147         }
 148
 149         client->head = head;
 150 }
 151
 152 static void __evdev_queue_syn_dropped(struct evdev_client *client)
 153 {
 154         struct input_event ev;
 155         ktime_t time;
 156         struct timespec64 ts;
 157
 158         time = client->clk_type == EV_CLK_REAL ?
 159                         ktime_get_real() :
 160                         client->clk_type == EV_CLK_MONO ?
 161                                 ktime_get() :
 162                                 ktime_get_boottime();
 163
 164         ts = ktime_to_timespec64(time);
 165         ev.input_event_sec = ts.tv_sec;
 166         ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 167         ev.type = EV_SYN;
 168         ev.code = SYN_DROPPED;
 169         ev.value = 0;
 170
 171         client->buffer[client->head++] = ev;
 172         client->head &= client->bufsize - 1;
 173
 174         if (unlikely(client->head == client->tail)) {
 175                 /* drop queue but keep our SYN_DROPPED event */
 176                 client->tail = (client->head - 1) & (client->bufsize - 1);
 177                 client->packet_head = client->tail;
 178         }
 179 }
 180
 181 static void evdev_queue_syn_dropped(struct evdev_client *client)
 182 {
 183         unsigned long flags;
 184
 185         spin_lock_irqsave(&client->buffer_lock, flags);
 186         __evdev_queue_syn_dropped(client);
 187         spin_unlock_irqrestore(&client->buffer_lock, flags);
 188 }
 189
 190 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
 191 {
 192         unsigned long flags;
 193         unsigned int clk_type;
 194
 195         switch (clkid) {
 196
 197         case CLOCK_REALTIME:
 198                 clk_type = EV_CLK_REAL;
 199                 break;
 200         case CLOCK_BOOTTIME:
 201         case CLOCK_MONOTONIC:
 202                 clk_type = EV_CLK_MONO;
 203                 break;
 204         default:
 205                 return -EINVAL;
 206         }
 207
 208         if (client->clk_type != clk_type) {
 209                 client->clk_type = clk_type;
 210
 211                 /*
 212                  * Flush pending events and queue SYN_DROPPED event,
 213                  * but only if the queue is not empty.
 214                  */
 215                 spin_lock_irqsave(&client->buffer_lock, flags);
 216
 217                 if (client->head != client->tail) {
 218                         client->packet_head = client->head = client->tail;
 219                         __evdev_queue_syn_dropped(client);
 220                 }
 221
 222                 spin_unlock_irqrestore(&client->buffer_lock, flags);
 223         }
 224
 225         return 0;
 226 }
 227
 228 static void __pass_event(struct evdev_client *client,
 229                          const struct input_event *event)
 230 {
 231         client->buffer[client->head++] = *event;
 232         client->head &= client->bufsize - 1;
 233
 234         if (unlikely(client->head == client->tail)) {
 235                 /*
 236                  * This effectively "drops" all unconsumed events, leaving
 237                  * EV_SYN/SYN_DROPPED plus the newest event in the queue.
 238                  */
 239                 client->tail = (client->head - 2) & (client->bufsize - 1);
 240
 241                 client->buffer[client->tail].input_event_sec =
 242                                                 event->input_event_sec;
 243                 client->buffer[client->tail].input_event_usec =
 244                                                 event->input_event_usec;
 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         struct timespec64 ts;
 266         bool wakeup = false;
 267
 268         if (client->revoked)
 269                 return;
 270
 271         ts = ktime_to_timespec64(ev_time[client->clk_type]);
 272         event.input_event_sec = ts.tv_sec;
 273         event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 274
 275         /* Interrupts are disabled, just acquire the lock. */
 276         spin_lock(&client->buffer_lock);
 277
 278         for (v = vals; v != vals + count; v++) {
 279                 if (__evdev_is_filtered(client, v->type, v->code))
 280                         continue;
 281
 282                 if (v->type == EV_SYN && v->code == SYN_REPORT) {
 283                         /* drop empty SYN_REPORT */
 284                         if (client->packet_head == client->head)
 285                                 continue;
 286
 287                         wakeup = true;
 288                 }
 289
 290                 event.type = v->type;
 291                 event.code = v->code;
 292                 event.value = v->value;
 293                 __pass_event(client, &event);
 294         }
 295
 296         spin_unlock(&client->buffer_lock);
 297
 298         if (wakeup)
 299                 wake_up_interruptible(&evdev->wait);
 300 }
 301
 302 /*
 303  * Pass incoming events to all connected clients.
 304  */
 305 static void evdev_events(struct input_handle *handle,
 306                          const struct input_value *vals, unsigned int count)
 307 {
 308         struct evdev *evdev = handle->private;
 309         struct evdev_client *client;
 310         ktime_t ev_time[EV_CLK_MAX];
 311
 312         ev_time[EV_CLK_MONO] = ktime_get();
 313         ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
 314
 315         rcu_read_lock();
 316
 317         client = rcu_dereference(evdev->grab);
 318
 319         if (client)
 320                 evdev_pass_values(client, vals, count, ev_time);
 321         else
 322                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 323                         evdev_pass_values(client, vals, count, ev_time);
 324
 325         rcu_read_unlock();
 326 }
 327
 328 /*
 329  * Pass incoming event to all connected clients.
 330  */
 331 static void evdev_event(struct input_handle *handle,
 332                         unsigned int type, unsigned int code, int value)
 333 {
 334         struct input_value vals[] = { { type, code, value } };
 335
 336         evdev_events(handle, vals, 1);
 337 }
 338
 339 static int evdev_fasync(int fd, struct file *file, int on)
 340 {
 341         struct evdev_client *client = file->private_data;
 342
 343         return fasync_helper(fd, file, on, &client->fasync);
 344 }
 345
 346 static int evdev_flush(struct file *file, fl_owner_t id)
 347 {
 348         struct evdev_client *client = file->private_data;
 349         struct evdev *evdev = client->evdev;
 350
 351         mutex_lock(&evdev->mutex);
 352
 353         if (evdev->exist && !client->revoked)
 354                 input_flush_device(&evdev->handle, file);
 355
 356         mutex_unlock(&evdev->mutex);
 357         return 0;
 358 }
 359
 360 static void evdev_free(struct device *dev)
 361 {
 362         struct evdev *evdev = container_of(dev, struct evdev, dev);
 363
 364         input_put_device(evdev->handle.dev);
 365         kfree(evdev);
 366 }
 367
 368 /*
 369  * Grabs an event device (along with underlying input device).
 370  * This function is called with evdev->mutex taken.
 371  */
 372 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 373 {
 374         int error;
 375
 376         if (evdev->grab)
 377                 return -EBUSY;
 378
 379         error = input_grab_device(&evdev->handle);
 380         if (error)
 381                 return error;
 382
 383         rcu_assign_pointer(evdev->grab, client);
 384
 385         return 0;
 386 }
 387
 388 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 389 {
 390         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 391                                         lockdep_is_held(&evdev->mutex));
 392
 393         if (grab != client)
 394                 return  -EINVAL;
 395
 396         rcu_assign_pointer(evdev->grab, NULL);
 397         synchronize_rcu();
 398         input_release_device(&evdev->handle);
 399
 400         return 0;
 401 }
 402
 403 static void evdev_attach_client(struct evdev *evdev,
 404                                 struct evdev_client *client)
 405 {
 406         spin_lock(&evdev->client_lock);
 407         list_add_tail_rcu(&client->node, &evdev->client_list);
 408         spin_unlock(&evdev->client_lock);
 409 }
 410
 411 static void evdev_detach_client(struct evdev *evdev,
 412                                 struct evdev_client *client)
 413 {
 414         spin_lock(&evdev->client_lock);
 415         list_del_rcu(&client->node);
 416         spin_unlock(&evdev->client_lock);
 417         synchronize_rcu();
 418 }
 419
 420 static int evdev_open_device(struct evdev *evdev)
 421 {
 422         int retval;
 423
 424         retval = mutex_lock_interruptible(&evdev->mutex);
 425         if (retval)
 426                 return retval;
 427
 428         if (!evdev->exist)
 429                 retval = -ENODEV;
 430         else if (!evdev->open++) {
 431                 retval = input_open_device(&evdev->handle);
 432                 if (retval)
 433                         evdev->open--;
 434         }
 435
 436         mutex_unlock(&evdev->mutex);
 437         return retval;
 438 }
 439
 440 static void evdev_close_device(struct evdev *evdev)
 441 {
 442         mutex_lock(&evdev->mutex);
 443
 444         if (evdev->exist && !--evdev->open)
 445                 input_close_device(&evdev->handle);
 446
 447         mutex_unlock(&evdev->mutex);
 448 }
 449
 450 /*
 451  * Wake up users waiting for IO so they can disconnect from
 452  * dead device.
 453  */
 454 static void evdev_hangup(struct evdev *evdev)
 455 {
 456         struct evdev_client *client;
 457
 458         spin_lock(&evdev->client_lock);
 459         list_for_each_entry(client, &evdev->client_list, node)
 460                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 461         spin_unlock(&evdev->client_lock);
 462
 463         wake_up_interruptible(&evdev->wait);
 464 }
 465
 466 static int evdev_release(struct inode *inode, struct file *file)
 467 {
 468         struct evdev_client *client = file->private_data;
 469         struct evdev *evdev = client->evdev;
 470         unsigned int i;
 471
 472         mutex_lock(&evdev->mutex);
 473         evdev_ungrab(evdev, client);
 474         mutex_unlock(&evdev->mutex);
 475
 476         evdev_detach_client(evdev, client);
 477
 478         for (i = 0; i < EV_CNT; ++i)
 479                 kfree(client->evmasks[i]);
 480
 481         kvfree(client);
 482
 483         evdev_close_device(evdev);
 484
 485         return 0;
 486 }
 487
 488 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 489 {
 490         unsigned int n_events =
 491                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 492                     EVDEV_MIN_BUFFER_SIZE);
 493
 494         return roundup_pow_of_two(n_events);
 495 }
 496
 497 static int evdev_open(struct inode *inode, struct file *file)
 498 {
 499         struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
 500         unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 501         unsigned int size = sizeof(struct evdev_client) +
 502                                         bufsize * sizeof(struct input_event);
 503         struct evdev_client *client;
 504         int error;
 505
 506         client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
 507         if (!client)
 508                 client = vzalloc(size);
 509         if (!client)
 510                 return -ENOMEM;
 511
 512         client->bufsize = bufsize;
 513         spin_lock_init(&client->buffer_lock);
 514         client->evdev = evdev;
 515         evdev_attach_client(evdev, client);
 516
 517         error = evdev_open_device(evdev);
 518         if (error)
 519                 goto err_free_client;
 520
 521         file->private_data = client;
 522         nonseekable_open(inode, file);
 523
 524         return 0;
 525
 526  err_free_client:
 527         evdev_detach_client(evdev, client);
 528         kvfree(client);
 529         return error;
 530 }
 531
 532 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 533                            size_t count, loff_t *ppos)
 534 {
 535         struct evdev_client *client = file->private_data;
 536         struct evdev *evdev = client->evdev;
 537         struct input_event event;
 538         int retval = 0;
 539
 540         if (count != 0 && count < input_event_size())
 541                 return -EINVAL;
 542
 543         retval = mutex_lock_interruptible(&evdev->mutex);
 544         if (retval)
 545                 return retval;
 546
 547         if (!evdev->exist || client->revoked) {
 548                 retval = -ENODEV;
 549                 goto out;
 550         }
 551
 552         while (retval + input_event_size() <= count) {
 553
 554                 if (input_event_from_user(buffer + retval, &event)) {
 555                         retval = -EFAULT;
 556                         goto out;
 557                 }
 558                 retval += input_event_size();
 559
 560                 input_inject_event(&evdev->handle,
 561                                    event.type, event.code, event.value);
 562         }
 563
 564  out:
 565         mutex_unlock(&evdev->mutex);
 566         return retval;
 567 }
 568
 569 static int evdev_fetch_next_event(struct evdev_client *client,
 570                                   struct input_event *event)
 571 {
 572         int have_event;
 573
 574         spin_lock_irq(&client->buffer_lock);
 575
 576         have_event = client->packet_head != client->tail;
 577         if (have_event) {
 578                 *event = client->buffer[client->tail++];
 579                 client->tail &= client->bufsize - 1;
 580         }
 581
 582         spin_unlock_irq(&client->buffer_lock);
 583
 584         return have_event;
 585 }
 586
 587 static ssize_t evdev_read(struct file *file, char __user *buffer,
 588                           size_t count, loff_t *ppos)
 589 {
 590         struct evdev_client *client = file->private_data;
 591         struct evdev *evdev = client->evdev;
 592         struct input_event event;
 593         size_t read = 0;
 594         int error;
 595
 596         if (count != 0 && count < input_event_size())
 597                 return -EINVAL;
 598
 599         for (;;) {
 600                 if (!evdev->exist || client->revoked)
 601                         return -ENODEV;
 602
 603                 if (client->packet_head == client->tail &&
 604                     (file->f_flags & O_NONBLOCK))
 605                         return -EAGAIN;
 606
 607                 /*
 608                  * count == 0 is special - no IO is done but we check
 609                  * for error conditions (see above).
 610                  */
 611                 if (count == 0)
 612                         break;
 613
 614                 while (read + input_event_size() <= count &&
 615                        evdev_fetch_next_event(client, &event)) {
 616
 617                         if (input_event_to_user(buffer + read, &event))
 618                                 return -EFAULT;
 619
 620                         read += input_event_size();
 621                 }
 622
 623                 if (read)
 624                         break;
 625
 626                 if (!(file->f_flags & O_NONBLOCK)) {
 627                         error = wait_event_interruptible(evdev->wait,
 628                                         client->packet_head != client->tail ||
 629                                         !evdev->exist || client->revoked);
 630                         if (error)
 631                                 return error;
 632                 }
 633         }
 634
 635         return read;
 636 }
 637
 638 /* No kernel lock - fine */
 639 static __poll_t evdev_poll(struct file *file, poll_table *wait)
 640 {
 641         struct evdev_client *client = file->private_data;
 642         struct evdev *evdev = client->evdev;
 643         __poll_t mask;
 644
 645         poll_wait(file, &evdev->wait, wait);
 646
 647         if (evdev->exist && !client->revoked)
 648                 mask = EPOLLOUT | EPOLLWRNORM;
 649         else
 650                 mask = EPOLLHUP | EPOLLERR;
 651
 652         if (client->packet_head != client->tail)
 653                 mask |= EPOLLIN | EPOLLRDNORM;
 654
 655         return mask;
 656 }
 657
 658 #ifdef CONFIG_COMPAT
 659
 660 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 661 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 662
 663 #ifdef __BIG_ENDIAN
 664 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 665                         unsigned int maxlen, void __user *p, int compat)
 666 {
 667         int len, i;
 668
 669         if (compat) {
 670                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 671                 if (len > maxlen)
 672                         len = maxlen;
 673
 674                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 675                         if (copy_to_user((compat_long_t __user *) p + i,
 676                                          (compat_long_t *) bits +
 677                                                 i + 1 - ((i % 2) << 1),
 678                                          sizeof(compat_long_t)))
 679                                 return -EFAULT;
 680         } else {
 681                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 682                 if (len > maxlen)
 683                         len = maxlen;
 684
 685                 if (copy_to_user(p, bits, len))
 686                         return -EFAULT;
 687         }
 688
 689         return len;
 690 }
 691
 692 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 693                           unsigned int maxlen, const void __user *p, int compat)
 694 {
 695         int len, i;
 696
 697         if (compat) {
 698                 if (maxlen % sizeof(compat_long_t))
 699                         return -EINVAL;
 700
 701                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 702                 if (len > maxlen)
 703                         len = maxlen;
 704
 705                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 706                         if (copy_from_user((compat_long_t *) bits +
 707                                                 i + 1 - ((i % 2) << 1),
 708                                            (compat_long_t __user *) p + i,
 709                                            sizeof(compat_long_t)))
 710                                 return -EFAULT;
 711                 if (i % 2)
 712                         *((compat_long_t *) bits + i - 1) = 0;
 713
 714         } else {
 715                 if (maxlen % sizeof(long))
 716                         return -EINVAL;
 717
 718                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 719                 if (len > maxlen)
 720                         len = maxlen;
 721
 722                 if (copy_from_user(bits, p, len))
 723                         return -EFAULT;
 724         }
 725
 726         return len;
 727 }
 728
 729 #else
 730
 731 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 732                         unsigned int maxlen, void __user *p, int compat)
 733 {
 734         int len = compat ?
 735                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 736                         BITS_TO_LONGS(maxbit) * sizeof(long);
 737
 738         if (len > maxlen)
 739                 len = maxlen;
 740
 741         return copy_to_user(p, bits, len) ? -EFAULT : len;
 742 }
 743
 744 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 745                           unsigned int maxlen, const void __user *p, int compat)
 746 {
 747         size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
 748         int len;
 749
 750         if (maxlen % chunk_size)
 751                 return -EINVAL;
 752
 753         len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
 754         len *= chunk_size;
 755         if (len > maxlen)
 756                 len = maxlen;
 757
 758         return copy_from_user(bits, p, len) ? -EFAULT : len;
 759 }
 760
 761 #endif /* __BIG_ENDIAN */
 762
 763 #else
 764
 765 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 766                         unsigned int maxlen, void __user *p, int compat)
 767 {
 768         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 769
 770         if (len > maxlen)
 771                 len = maxlen;
 772
 773         return copy_to_user(p, bits, len) ? -EFAULT : len;
 774 }
 775
 776 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 777                           unsigned int maxlen, const void __user *p, int compat)
 778 {
 779         int len;
 780
 781         if (maxlen % sizeof(long))
 782                 return -EINVAL;
 783
 784         len = BITS_TO_LONGS(maxbit) * sizeof(long);
 785         if (len > maxlen)
 786                 len = maxlen;
 787
 788         return copy_from_user(bits, p, len) ? -EFAULT : len;
 789 }
 790
 791 #endif /* CONFIG_COMPAT */
 792
 793 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 794 {
 795         int len;
 796
 797         if (!str)
 798                 return -ENOENT;
 799
 800         len = strlen(str) + 1;
 801         if (len > maxlen)
 802                 len = maxlen;
 803
 804         return copy_to_user(p, str, len) ? -EFAULT : len;
 805 }
 806
 807 static int handle_eviocgbit(struct input_dev *dev,
 808                             unsigned int type, unsigned int size,
 809                             void __user *p, int compat_mode)
 810 {
 811         unsigned long *bits;
 812         int len;
 813
 814         switch (type) {
 815
 816         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 817         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 818         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 819         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 820         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 821         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 822         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 823         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 824         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 825         default: return -EINVAL;
 826         }
 827
 828         return bits_to_user(bits, len, size, p, compat_mode);
 829 }
 830
 831 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 832 {
 833         struct input_keymap_entry ke = {
 834                 .len    = sizeof(unsigned int),
 835                 .flags  = 0,
 836         };
 837         int __user *ip = (int __user *)p;
 838         int error;
 839
 840         /* legacy case */
 841         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 842                 return -EFAULT;
 843
 844         error = input_get_keycode(dev, &ke);
 845         if (error)
 846                 return error;
 847
 848         if (put_user(ke.keycode, ip + 1))
 849                 return -EFAULT;
 850
 851         return 0;
 852 }
 853
 854 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 855 {
 856         struct input_keymap_entry ke;
 857         int error;
 858
 859         if (copy_from_user(&ke, p, sizeof(ke)))
 860                 return -EFAULT;
 861
 862         error = input_get_keycode(dev, &ke);
 863         if (error)
 864                 return error;
 865
 866         if (copy_to_user(p, &ke, sizeof(ke)))
 867                 return -EFAULT;
 868
 869         return 0;
 870 }
 871
 872 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 873 {
 874         struct input_keymap_entry ke = {
 875                 .len    = sizeof(unsigned int),
 876                 .flags  = 0,
 877         };
 878         int __user *ip = (int __user *)p;
 879
 880         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 881                 return -EFAULT;
 882
 883         if (get_user(ke.keycode, ip + 1))
 884                 return -EFAULT;
 885
 886         return input_set_keycode(dev, &ke);
 887 }
 888
 889 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 890 {
 891         struct input_keymap_entry ke;
 892
 893         if (copy_from_user(&ke, p, sizeof(ke)))
 894                 return -EFAULT;
 895
 896         if (ke.len > sizeof(ke.scancode))
 897                 return -EINVAL;
 898
 899         return input_set_keycode(dev, &ke);
 900 }
 901
 902 /*
 903  * If we transfer state to the user, we should flush all pending events
 904  * of the same type from the client's queue. Otherwise, they might end up
 905  * with duplicate events, which can screw up client's state tracking.
 906  * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
 907  * event so user-space will notice missing events.
 908  *
 909  * LOCKING:
 910  * We need to take event_lock before buffer_lock to avoid dead-locks. But we
 911  * need the even_lock only to guarantee consistent state. We can safely release
 912  * it while flushing the queue. This allows input-core to handle filters while
 913  * we flush the queue.
 914  */
 915 static int evdev_handle_get_val(struct evdev_client *client,
 916                                 struct input_dev *dev, unsigned int type,
 917                                 unsigned long *bits, unsigned int maxbit,
 918                                 unsigned int maxlen, void __user *p,
 919                                 int compat)
 920 {
 921         int ret;
 922         unsigned long *mem;
 923         size_t len;
 924
 925         len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
 926         mem = kmalloc(len, GFP_KERNEL);
 927         if (!mem)
 928                 return -ENOMEM;
 929
 930         spin_lock_irq(&dev->event_lock);
 931         spin_lock(&client->buffer_lock);
 932
 933         memcpy(mem, bits, len);
 934
 935         spin_unlock(&dev->event_lock);
 936
 937         __evdev_flush_queue(client, type);
 938
 939         spin_unlock_irq(&client->buffer_lock);
 940
 941         ret = bits_to_user(mem, maxbit, maxlen, p, compat);
 942         if (ret < 0)
 943                 evdev_queue_syn_dropped(client);
 944
 945         kfree(mem);
 946
 947         return ret;
 948 }
 949
 950 static int evdev_handle_mt_request(struct input_dev *dev,
 951                                    unsigned int size,
 952                                    int __user *ip)
 953 {
 954         const struct input_mt *mt = dev->mt;
 955         unsigned int code;
 956         int max_slots;
 957         int i;
 958
 959         if (get_user(code, &ip[0]))
 960                 return -EFAULT;
 961         if (!mt || !input_is_mt_value(code))
 962                 return -EINVAL;
 963
 964         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 965         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 966                 int value = input_mt_get_value(&mt->slots[i], code);
 967                 if (put_user(value, &ip[1 + i]))
 968                         return -EFAULT;
 969         }
 970
 971         return 0;
 972 }
 973
 974 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
 975                         struct file *file)
 976 {
 977         client->revoked = true;
 978         evdev_ungrab(evdev, client);
 979         input_flush_device(&evdev->handle, file);
 980         wake_up_interruptible(&evdev->wait);
 981
 982         return 0;
 983 }
 984
 985 /* must be called with evdev-mutex held */
 986 static int evdev_set_mask(struct evdev_client *client,
 987                           unsigned int type,
 988                           const void __user *codes,
 989                           u32 codes_size,
 990                           int compat)
 991 {
 992         unsigned long flags, *mask, *oldmask;
 993         size_t cnt;
 994         int error;
 995
 996         /* we allow unknown types and 'codes_size > size' for forward-compat */
 997         cnt = evdev_get_mask_cnt(type);
 998         if (!cnt)
 999                 return 0;
1000
1001         mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL);
1002         if (!mask)
1003                 return -ENOMEM;
1004
1005         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1006         if (error < 0) {
1007                 kfree(mask);
1008                 return error;
1009         }
1010
1011         spin_lock_irqsave(&client->buffer_lock, flags);
1012         oldmask = client->evmasks[type];
1013         client->evmasks[type] = mask;
1014         spin_unlock_irqrestore(&client->buffer_lock, flags);
1015
1016         kfree(oldmask);
1017
1018         return 0;
1019 }
1020
1021 /* must be called with evdev-mutex held */
1022 static int evdev_get_mask(struct evdev_client *client,
1023                           unsigned int type,
1024                           void __user *codes,
1025                           u32 codes_size,
1026                           int compat)
1027 {
1028         unsigned long *mask;
1029         size_t cnt, size, xfer_size;
1030         int i;
1031         int error;
1032
1033         /* we allow unknown types and 'codes_size > size' for forward-compat */
1034         cnt = evdev_get_mask_cnt(type);
1035         size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1036         xfer_size = min_t(size_t, codes_size, size);
1037
1038         if (cnt > 0) {
1039                 mask = client->evmasks[type];
1040                 if (mask) {
1041                         error = bits_to_user(mask, cnt - 1,
1042                                              xfer_size, codes, compat);
1043                         if (error < 0)
1044                                 return error;
1045                 } else {
1046                         /* fake mask with all bits set */
1047                         for (i = 0; i < xfer_size; i++)
1048                                 if (put_user(0xffU, (u8 __user *)codes + i))
1049                                         return -EFAULT;
1050                 }
1051         }
1052
1053         if (xfer_size < codes_size)
1054                 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1055                         return -EFAULT;
1056
1057         return 0;
1058 }
1059
1060 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1061                            void __user *p, int compat_mode)
1062 {
1063         struct evdev_client *client = file->private_data;
1064         struct evdev *evdev = client->evdev;
1065         struct input_dev *dev = evdev->handle.dev;
1066         struct input_absinfo abs;
1067         struct input_mask mask;
1068         struct ff_effect effect;
1069         int __user *ip = (int __user *)p;
1070         unsigned int i, t, u, v;
1071         unsigned int size;
1072         int error;
1073
1074         /* First we check for fixed-length commands */
1075         switch (cmd) {
1076
1077         case EVIOCGVERSION:
1078                 return put_user(EV_VERSION, ip);
1079
1080         case EVIOCGID:
1081                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1082                         return -EFAULT;
1083                 return 0;
1084
1085         case EVIOCGREP:
1086                 if (!test_bit(EV_REP, dev->evbit))
1087                         return -ENOSYS;
1088                 if (put_user(dev->rep[REP_DELAY], ip))
1089                         return -EFAULT;
1090                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1091                         return -EFAULT;
1092                 return 0;
1093
1094         case EVIOCSREP:
1095                 if (!test_bit(EV_REP, dev->evbit))
1096                         return -ENOSYS;
1097                 if (get_user(u, ip))
1098                         return -EFAULT;
1099                 if (get_user(v, ip + 1))
1100                         return -EFAULT;
1101
1102                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1103                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1104
1105                 return 0;
1106
1107         case EVIOCRMFF:
1108                 return input_ff_erase(dev, (int)(unsigned long) p, file);
1109
1110         case EVIOCGEFFECTS:
1111                 i = test_bit(EV_FF, dev->evbit) ?
1112                                 dev->ff->max_effects : 0;
1113                 if (put_user(i, ip))
1114                         return -EFAULT;
1115                 return 0;
1116
1117         case EVIOCGRAB:
1118                 if (p)
1119                         return evdev_grab(evdev, client);
1120                 else
1121                         return evdev_ungrab(evdev, client);
1122
1123         case EVIOCREVOKE:
1124                 if (p)
1125                         return -EINVAL;
1126                 else
1127                         return evdev_revoke(evdev, client, file);
1128
1129         case EVIOCGMASK: {
1130                 void __user *codes_ptr;
1131
1132                 if (copy_from_user(&mask, p, sizeof(mask)))
1133                         return -EFAULT;
1134
1135                 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1136                 return evdev_get_mask(client,
1137                                       mask.type, codes_ptr, mask.codes_size,
1138                                       compat_mode);
1139         }
1140
1141         case EVIOCSMASK: {
1142                 const void __user *codes_ptr;
1143
1144                 if (copy_from_user(&mask, p, sizeof(mask)))
1145                         return -EFAULT;
1146
1147                 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1148                 return evdev_set_mask(client,
1149                                       mask.type, codes_ptr, mask.codes_size,
1150                                       compat_mode);
1151         }
1152
1153         case EVIOCSCLOCKID:
1154                 if (copy_from_user(&i, p, sizeof(unsigned int)))
1155                         return -EFAULT;
1156
1157                 return evdev_set_clk_type(client, i);
1158
1159         case EVIOCGKEYCODE:
1160                 return evdev_handle_get_keycode(dev, p);
1161
1162         case EVIOCSKEYCODE:
1163                 return evdev_handle_set_keycode(dev, p);
1164
1165         case EVIOCGKEYCODE_V2:
1166                 return evdev_handle_get_keycode_v2(dev, p);
1167
1168         case EVIOCSKEYCODE_V2:
1169                 return evdev_handle_set_keycode_v2(dev, p);
1170         }
1171
1172         size = _IOC_SIZE(cmd);
1173
1174         /* Now check variable-length commands */
1175 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1176         switch (EVIOC_MASK_SIZE(cmd)) {
1177
1178         case EVIOCGPROP(0):
1179                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1180                                     size, p, compat_mode);
1181
1182         case EVIOCGMTSLOTS(0):
1183                 return evdev_handle_mt_request(dev, size, ip);
1184
1185         case EVIOCGKEY(0):
1186                 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1187                                             KEY_MAX, size, p, compat_mode);
1188
1189         case EVIOCGLED(0):
1190                 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1191                                             LED_MAX, size, p, compat_mode);
1192
1193         case EVIOCGSND(0):
1194                 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1195                                             SND_MAX, size, p, compat_mode);
1196
1197         case EVIOCGSW(0):
1198                 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1199                                             SW_MAX, size, p, compat_mode);
1200
1201         case EVIOCGNAME(0):
1202                 return str_to_user(dev->name, size, p);
1203
1204         case EVIOCGPHYS(0):
1205                 return str_to_user(dev->phys, size, p);
1206
1207         case EVIOCGUNIQ(0):
1208                 return str_to_user(dev->uniq, size, p);
1209
1210         case EVIOC_MASK_SIZE(EVIOCSFF):
1211                 if (input_ff_effect_from_user(p, size, &effect))
1212                         return -EFAULT;
1213
1214                 error = input_ff_upload(dev, &effect, file);
1215                 if (error)
1216                         return error;
1217
1218                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1219                         return -EFAULT;
1220
1221                 return 0;
1222         }
1223
1224         /* Multi-number variable-length handlers */
1225         if (_IOC_TYPE(cmd) != 'E')
1226                 return -EINVAL;
1227
1228         if (_IOC_DIR(cmd) == _IOC_READ) {
1229
1230                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1231                         return handle_eviocgbit(dev,
1232                                                 _IOC_NR(cmd) & EV_MAX, size,
1233                                                 p, compat_mode);
1234
1235                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1236
1237                         if (!dev->absinfo)
1238                                 return -EINVAL;
1239
1240                         t = _IOC_NR(cmd) & ABS_MAX;
1241                         abs = dev->absinfo[t];
1242
1243                         if (copy_to_user(p, &abs, min_t(size_t,
1244                                         size, sizeof(struct input_absinfo))))
1245                                 return -EFAULT;
1246
1247                         return 0;
1248                 }
1249         }
1250
1251         if (_IOC_DIR(cmd) == _IOC_WRITE) {
1252
1253                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1254
1255                         if (!dev->absinfo)
1256                                 return -EINVAL;
1257
1258                         t = _IOC_NR(cmd) & ABS_MAX;
1259
1260                         if (copy_from_user(&abs, p, min_t(size_t,
1261                                         size, sizeof(struct input_absinfo))))
1262                                 return -EFAULT;
1263
1264                         if (size < sizeof(struct input_absinfo))
1265                                 abs.resolution = 0;
1266
1267                         /* We can't change number of reserved MT slots */
1268                         if (t == ABS_MT_SLOT)
1269                                 return -EINVAL;
1270
1271                         /*
1272                          * Take event lock to ensure that we are not
1273                          * changing device parameters in the middle
1274                          * of event.
1275                          */
1276                         spin_lock_irq(&dev->event_lock);
1277                         dev->absinfo[t] = abs;
1278                         spin_unlock_irq(&dev->event_lock);
1279
1280                         return 0;
1281                 }
1282         }
1283
1284         return -EINVAL;
1285 }
1286
1287 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1288                                 void __user *p, int compat_mode)
1289 {
1290         struct evdev_client *client = file->private_data;
1291         struct evdev *evdev = client->evdev;
1292         int retval;
1293
1294         retval = mutex_lock_interruptible(&evdev->mutex);
1295         if (retval)
1296                 return retval;
1297
1298         if (!evdev->exist || client->revoked) {
1299                 retval = -ENODEV;
1300                 goto out;
1301         }
1302
1303         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1304
1305  out:
1306         mutex_unlock(&evdev->mutex);
1307         return retval;
1308 }
1309
1310 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1311 {
1312         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1313 }
1314
1315 #ifdef CONFIG_COMPAT
1316 static long evdev_ioctl_compat(struct file *file,
1317                                 unsigned int cmd, unsigned long arg)
1318 {
1319         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1320 }
1321 #endif
1322
1323 static const struct file_operations evdev_fops = {
1324         .owner          = THIS_MODULE,
1325         .read           = evdev_read,
1326         .write          = evdev_write,
1327         .poll           = evdev_poll,
1328         .open           = evdev_open,
1329         .release        = evdev_release,
1330         .unlocked_ioctl = evdev_ioctl,
1331 #ifdef CONFIG_COMPAT
1332         .compat_ioctl   = evdev_ioctl_compat,
1333 #endif
1334         .fasync         = evdev_fasync,
1335         .flush          = evdev_flush,
1336         .llseek         = no_llseek,
1337 };
1338
1339 /*
1340  * Mark device non-existent. This disables writes, ioctls and
1341  * prevents new users from opening the device. Already posted
1342  * blocking reads will stay, however new ones will fail.
1343  */
1344 static void evdev_mark_dead(struct evdev *evdev)
1345 {
1346         mutex_lock(&evdev->mutex);
1347         evdev->exist = false;
1348         mutex_unlock(&evdev->mutex);
1349 }
1350
1351 static void evdev_cleanup(struct evdev *evdev)
1352 {
1353         struct input_handle *handle = &evdev->handle;
1354
1355         evdev_mark_dead(evdev);
1356         evdev_hangup(evdev);
1357
1358         /* evdev is marked dead so no one else accesses evdev->open */
1359         if (evdev->open) {
1360                 input_flush_device(handle, NULL);
1361                 input_close_device(handle);
1362         }
1363 }
1364
1365 /*
1366  * Create new evdev device. Note that input core serializes calls
1367  * to connect and disconnect.
1368  */
1369 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1370                          const struct input_device_id *id)
1371 {
1372         struct evdev *evdev;
1373         int minor;
1374         int dev_no;
1375         int error;
1376
1377         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1378         if (minor < 0) {
1379                 error = minor;
1380                 pr_err("failed to reserve new minor: %d\n", error);
1381                 return error;
1382         }
1383
1384         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1385         if (!evdev) {
1386                 error = -ENOMEM;
1387                 goto err_free_minor;
1388         }
1389
1390         INIT_LIST_HEAD(&evdev->client_list);
1391         spin_lock_init(&evdev->client_lock);
1392         mutex_init(&evdev->mutex);
1393         init_waitqueue_head(&evdev->wait);
1394         evdev->exist = true;
1395
1396         dev_no = minor;
1397         /* Normalize device number if it falls into legacy range */
1398         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1399                 dev_no -= EVDEV_MINOR_BASE;
1400         dev_set_name(&evdev->dev, "event%d", dev_no);
1401
1402         evdev->handle.dev = input_get_device(dev);
1403         evdev->handle.name = dev_name(&evdev->dev);
1404         evdev->handle.handler = handler;
1405         evdev->handle.private = evdev;
1406
1407         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1408         evdev->dev.class = &input_class;
1409         evdev->dev.parent = &dev->dev;
1410         evdev->dev.release = evdev_free;
1411         device_initialize(&evdev->dev);
1412
1413         error = input_register_handle(&evdev->handle);
1414         if (error)
1415                 goto err_free_evdev;
1416
1417         cdev_init(&evdev->cdev, &evdev_fops);
1418
1419         error = cdev_device_add(&evdev->cdev, &evdev->dev);
1420         if (error)
1421                 goto err_cleanup_evdev;
1422
1423         return 0;
1424
1425  err_cleanup_evdev:
1426         evdev_cleanup(evdev);
1427         input_unregister_handle(&evdev->handle);
1428  err_free_evdev:
1429         put_device(&evdev->dev);
1430  err_free_minor:
1431         input_free_minor(minor);
1432         return error;
1433 }
1434
1435 static void evdev_disconnect(struct input_handle *handle)
1436 {
1437         struct evdev *evdev = handle->private;
1438
1439         cdev_device_del(&evdev->cdev, &evdev->dev);
1440         evdev_cleanup(evdev);
1441         input_free_minor(MINOR(evdev->dev.devt));
1442         input_unregister_handle(handle);
1443         put_device(&evdev->dev);
1444 }
1445
1446 static const struct input_device_id evdev_ids[] = {
1447         { .driver_info = 1 },   /* Matches all devices */
1448         { },                    /* Terminating zero entry */
1449 };
1450
1451 MODULE_DEVICE_TABLE(input, evdev_ids);
1452
1453 static struct input_handler evdev_handler = {
1454         .event          = evdev_event,
1455         .events         = evdev_events,
1456         .connect        = evdev_connect,
1457         .disconnect     = evdev_disconnect,
1458         .legacy_minors  = true,
1459         .minor          = EVDEV_MINOR_BASE,
1460         .name           = "evdev",
1461         .id_table       = evdev_ids,
1462 };
1463
1464 static int __init evdev_init(void)
1465 {
1466         return input_register_handler(&evdev_handler);
1467 }
1468
1469 static void __exit evdev_exit(void)
1470 {
1471         input_unregister_handler(&evdev_handler);
1472 }
1473
1474 module_init(evdev_init);
1475 module_exit(evdev_exit);
1476
1477 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1478 MODULE_DESCRIPTION("Input driver event char devices");
1479 MODULE_LICENSE("GPL");