drivers/input/evdev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Event char devices, giving access to raw input device events.
   4  *
   5  * Copyright (c) 1999-2002 Vojtech Pavlik
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #define EVDEV_MINOR_BASE        64
  11 #define EVDEV_MINORS            32
  12 #define EVDEV_MIN_BUFFER_SIZE   64U
  13 #define EVDEV_BUF_PACKETS       8
  14
  15 #include <linux/poll.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/vmalloc.h>
  19 #include <linux/mm.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/input/mt.h>
  23 #include <linux/major.h>
  24 #include <linux/device.h>
  25 #include <linux/cdev.h>
  26 #include "input-compat.h"
  27
  28 enum evdev_clock_type {
  29         EV_CLK_REAL = 0,
  30         EV_CLK_MONO,
  31         EV_CLK_BOOT,
  32         EV_CLK_MAX
  33 };
  34
  35 struct evdev {
  36         int open;
  37         struct input_handle handle;
  38         wait_queue_head_t wait;
  39         struct evdev_client __rcu *grab;
  40         struct list_head client_list;
  41         spinlock_t client_lock; /* protects client_list */
  42         struct mutex mutex;
  43         struct device dev;
  44         struct cdev cdev;
  45         bool exist;
  46 };
  47
  48 struct evdev_client {
  49         unsigned int head;
  50         unsigned int tail;
  51         unsigned int packet_head; /* [future] position of the first element of next packet */
  52         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  53         struct fasync_struct *fasync;
  54         struct evdev *evdev;
  55         struct list_head node;
  56         unsigned int clk_type;
  57         bool revoked;
  58         unsigned long *evmasks[EV_CNT];
  59         unsigned int bufsize;
  60         struct input_event buffer[];
  61 };
  62
  63 static size_t evdev_get_mask_cnt(unsigned int type)
  64 {
  65         static const size_t counts[EV_CNT] = {
  66                 /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
  67                 [EV_SYN]        = EV_CNT,
  68                 [EV_KEY]        = KEY_CNT,
  69                 [EV_REL]        = REL_CNT,
  70                 [EV_ABS]        = ABS_CNT,
  71                 [EV_MSC]        = MSC_CNT,
  72                 [EV_SW]         = SW_CNT,
  73                 [EV_LED]        = LED_CNT,
  74                 [EV_SND]        = SND_CNT,
  75                 [EV_FF]         = FF_CNT,
  76         };
  77
  78         return (type < EV_CNT) ? counts[type] : 0;
  79 }
  80
  81 /* requires the buffer lock to be held */
  82 static bool __evdev_is_filtered(struct evdev_client *client,
  83                                 unsigned int type,
  84                                 unsigned int code)
  85 {
  86         unsigned long *mask;
  87         size_t cnt;
  88
  89         /* EV_SYN and unknown codes are never filtered */
  90         if (type == EV_SYN || type >= EV_CNT)
  91                 return false;
  92
  93         /* first test whether the type is filtered */
  94         mask = client->evmasks[0];
  95         if (mask && !test_bit(type, mask))
  96                 return true;
  97
  98         /* unknown values are never filtered */
  99         cnt = evdev_get_mask_cnt(type);
 100         if (!cnt || code >= cnt)
 101                 return false;
 102
 103         mask = client->evmasks[type];
 104         return mask && !test_bit(code, mask);
 105 }
 106
 107 /* flush queued events of type @type, caller must hold client->buffer_lock */
 108 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
 109 {
 110         unsigned int i, head, num;
 111         unsigned int mask = client->bufsize - 1;
 112         bool is_report;
 113         struct input_event *ev;
 114
 115         BUG_ON(type == EV_SYN);
 116
 117         head = client->tail;
 118         client->packet_head = client->tail;
 119
 120         /* init to 1 so a leading SYN_REPORT will not be dropped */
 121         num = 1;
 122
 123         for (i = client->tail; i != client->head; i = (i + 1) & mask) {
 124                 ev = &client->buffer[i];
 125                 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
 126
 127                 if (ev->type == type) {
 128                         /* drop matched entry */
 129                         continue;
 130                 } else if (is_report && !num) {
 131                         /* drop empty SYN_REPORT groups */
 132                         continue;
 133                 } else if (head != i) {
 134                         /* move entry to fill the gap */
 135                         client->buffer[head] = *ev;
 136                 }
 137
 138                 num++;
 139                 head = (head + 1) & mask;
 140
 141                 if (is_report) {
 142                         num = 0;
 143                         client->packet_head = head;
 144                 }
 145         }
 146
 147         client->head = head;
 148 }
 149
 150 static void __evdev_queue_syn_dropped(struct evdev_client *client)
 151 {
 152         struct input_event ev;
 153         ktime_t time;
 154         struct timespec64 ts;
 155
 156         time = client->clk_type == EV_CLK_REAL ?
 157                         ktime_get_real() :
 158                         client->clk_type == EV_CLK_MONO ?
 159                                 ktime_get() :
 160                                 ktime_get_boottime();
 161
 162         ts = ktime_to_timespec64(time);
 163         ev.input_event_sec = ts.tv_sec;
 164         ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 165         ev.type = EV_SYN;
 166         ev.code = SYN_DROPPED;
 167         ev.value = 0;
 168
 169         client->buffer[client->head++] = ev;
 170         client->head &= client->bufsize - 1;
 171
 172         if (unlikely(client->head == client->tail)) {
 173                 /* drop queue but keep our SYN_DROPPED event */
 174                 client->tail = (client->head - 1) & (client->bufsize - 1);
 175                 client->packet_head = client->tail;
 176         }
 177 }
 178
 179 static void evdev_queue_syn_dropped(struct evdev_client *client)
 180 {
 181         unsigned long flags;
 182
 183         spin_lock_irqsave(&client->buffer_lock, flags);
 184         __evdev_queue_syn_dropped(client);
 185         spin_unlock_irqrestore(&client->buffer_lock, flags);
 186 }
 187
 188 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
 189 {
 190         unsigned long flags;
 191         unsigned int clk_type;
 192
 193         switch (clkid) {
 194
 195         case CLOCK_REALTIME:
 196                 clk_type = EV_CLK_REAL;
 197                 break;
 198         case CLOCK_MONOTONIC:
 199                 clk_type = EV_CLK_MONO;
 200                 break;
 201         case CLOCK_BOOTTIME:
 202                 clk_type = EV_CLK_BOOT;
 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         ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
 315                                                  TK_OFFS_BOOT);
 316
 317         rcu_read_lock();
 318
 319         client = rcu_dereference(evdev->grab);
 320
 321         if (client)
 322                 evdev_pass_values(client, vals, count, ev_time);
 323         else
 324                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 325                         evdev_pass_values(client, vals, count, ev_time);
 326
 327         rcu_read_unlock();
 328 }
 329
 330 /*
 331  * Pass incoming event to all connected clients.
 332  */
 333 static void evdev_event(struct input_handle *handle,
 334                         unsigned int type, unsigned int code, int value)
 335 {
 336         struct input_value vals[] = { { type, code, value } };
 337
 338         evdev_events(handle, vals, 1);
 339 }
 340
 341 static int evdev_fasync(int fd, struct file *file, int on)
 342 {
 343         struct evdev_client *client = file->private_data;
 344
 345         return fasync_helper(fd, file, on, &client->fasync);
 346 }
 347
 348 static int evdev_flush(struct file *file, fl_owner_t id)
 349 {
 350         struct evdev_client *client = file->private_data;
 351         struct evdev *evdev = client->evdev;
 352
 353         mutex_lock(&evdev->mutex);
 354
 355         if (evdev->exist && !client->revoked)
 356                 input_flush_device(&evdev->handle, file);
 357
 358         mutex_unlock(&evdev->mutex);
 359         return 0;
 360 }
 361
 362 static void evdev_free(struct device *dev)
 363 {
 364         struct evdev *evdev = container_of(dev, struct evdev, dev);
 365
 366         input_put_device(evdev->handle.dev);
 367         kfree(evdev);
 368 }
 369
 370 /*
 371  * Grabs an event device (along with underlying input device).
 372  * This function is called with evdev->mutex taken.
 373  */
 374 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 375 {
 376         int error;
 377
 378         if (evdev->grab)
 379                 return -EBUSY;
 380
 381         error = input_grab_device(&evdev->handle);
 382         if (error)
 383                 return error;
 384
 385         rcu_assign_pointer(evdev->grab, client);
 386
 387         return 0;
 388 }
 389
 390 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 391 {
 392         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 393                                         lockdep_is_held(&evdev->mutex));
 394
 395         if (grab != client)
 396                 return  -EINVAL;
 397
 398         rcu_assign_pointer(evdev->grab, NULL);
 399         synchronize_rcu();
 400         input_release_device(&evdev->handle);
 401
 402         return 0;
 403 }
 404
 405 static void evdev_attach_client(struct evdev *evdev,
 406                                 struct evdev_client *client)
 407 {
 408         spin_lock(&evdev->client_lock);
 409         list_add_tail_rcu(&client->node, &evdev->client_list);
 410         spin_unlock(&evdev->client_lock);
 411 }
 412
 413 static void evdev_detach_client(struct evdev *evdev,
 414                                 struct evdev_client *client)
 415 {
 416         spin_lock(&evdev->client_lock);
 417         list_del_rcu(&client->node);
 418         spin_unlock(&evdev->client_lock);
 419         synchronize_rcu();
 420 }
 421
 422 static int evdev_open_device(struct evdev *evdev)
 423 {
 424         int retval;
 425
 426         retval = mutex_lock_interruptible(&evdev->mutex);
 427         if (retval)
 428                 return retval;
 429
 430         if (!evdev->exist)
 431                 retval = -ENODEV;
 432         else if (!evdev->open++) {
 433                 retval = input_open_device(&evdev->handle);
 434                 if (retval)
 435                         evdev->open--;
 436         }
 437
 438         mutex_unlock(&evdev->mutex);
 439         return retval;
 440 }
 441
 442 static void evdev_close_device(struct evdev *evdev)
 443 {
 444         mutex_lock(&evdev->mutex);
 445
 446         if (evdev->exist && !--evdev->open)
 447                 input_close_device(&evdev->handle);
 448
 449         mutex_unlock(&evdev->mutex);
 450 }
 451
 452 /*
 453  * Wake up users waiting for IO so they can disconnect from
 454  * dead device.
 455  */
 456 static void evdev_hangup(struct evdev *evdev)
 457 {
 458         struct evdev_client *client;
 459
 460         spin_lock(&evdev->client_lock);
 461         list_for_each_entry(client, &evdev->client_list, node)
 462                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 463         spin_unlock(&evdev->client_lock);
 464
 465         wake_up_interruptible(&evdev->wait);
 466 }
 467
 468 static int evdev_release(struct inode *inode, struct file *file)
 469 {
 470         struct evdev_client *client = file->private_data;
 471         struct evdev *evdev = client->evdev;
 472         unsigned int i;
 473
 474         mutex_lock(&evdev->mutex);
 475         evdev_ungrab(evdev, client);
 476         mutex_unlock(&evdev->mutex);
 477
 478         evdev_detach_client(evdev, client);
 479
 480         for (i = 0; i < EV_CNT; ++i)
 481                 bitmap_free(client->evmasks[i]);
 482
 483         kvfree(client);
 484
 485         evdev_close_device(evdev);
 486
 487         return 0;
 488 }
 489
 490 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 491 {
 492         unsigned int n_events =
 493                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 494                     EVDEV_MIN_BUFFER_SIZE);
 495
 496         return roundup_pow_of_two(n_events);
 497 }
 498
 499 static int evdev_open(struct inode *inode, struct file *file)
 500 {
 501         struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
 502         unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 503         struct evdev_client *client;
 504         int error;
 505
 506         client = kzalloc(struct_size(client, buffer, bufsize),
 507                          GFP_KERNEL | __GFP_NOWARN);
 508         if (!client)
 509                 client = vzalloc(struct_size(client, buffer, bufsize));
 510         if (!client)
 511                 return -ENOMEM;
 512
 513         client->bufsize = bufsize;
 514         spin_lock_init(&client->buffer_lock);
 515         client->evdev = evdev;
 516         evdev_attach_client(evdev, client);
 517
 518         error = evdev_open_device(evdev);
 519         if (error)
 520                 goto err_free_client;
 521
 522         file->private_data = client;
 523         stream_open(inode, file);
 524
 525         return 0;
 526
 527  err_free_client:
 528         evdev_detach_client(evdev, client);
 529         kvfree(client);
 530         return error;
 531 }
 532
 533 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 534                            size_t count, loff_t *ppos)
 535 {
 536         struct evdev_client *client = file->private_data;
 537         struct evdev *evdev = client->evdev;
 538         struct input_event event;
 539         int retval = 0;
 540
 541         if (count != 0 && count < input_event_size())
 542                 return -EINVAL;
 543
 544         retval = mutex_lock_interruptible(&evdev->mutex);
 545         if (retval)
 546                 return retval;
 547
 548         if (!evdev->exist || client->revoked) {
 549                 retval = -ENODEV;
 550                 goto out;
 551         }
 552
 553         while (retval + input_event_size() <= count) {
 554
 555                 if (input_event_from_user(buffer + retval, &event)) {
 556                         retval = -EFAULT;
 557                         goto out;
 558                 }
 559                 retval += input_event_size();
 560
 561                 input_inject_event(&evdev->handle,
 562                                    event.type, event.code, event.value);
 563                 cond_resched();
 564         }
 565
 566  out:
 567         mutex_unlock(&evdev->mutex);
 568         return retval;
 569 }
 570
 571 static int evdev_fetch_next_event(struct evdev_client *client,
 572                                   struct input_event *event)
 573 {
 574         int have_event;
 575
 576         spin_lock_irq(&client->buffer_lock);
 577
 578         have_event = client->packet_head != client->tail;
 579         if (have_event) {
 580                 *event = client->buffer[client->tail++];
 581                 client->tail &= client->bufsize - 1;
 582         }
 583
 584         spin_unlock_irq(&client->buffer_lock);
 585
 586         return have_event;
 587 }
 588
 589 static ssize_t evdev_read(struct file *file, char __user *buffer,
 590                           size_t count, loff_t *ppos)
 591 {
 592         struct evdev_client *client = file->private_data;
 593         struct evdev *evdev = client->evdev;
 594         struct input_event event;
 595         size_t read = 0;
 596         int error;
 597
 598         if (count != 0 && count < input_event_size())
 599                 return -EINVAL;
 600
 601         for (;;) {
 602                 if (!evdev->exist || client->revoked)
 603                         return -ENODEV;
 604
 605                 if (client->packet_head == client->tail &&
 606                     (file->f_flags & O_NONBLOCK))
 607                         return -EAGAIN;
 608
 609                 /*
 610                  * count == 0 is special - no IO is done but we check
 611                  * for error conditions (see above).
 612                  */
 613                 if (count == 0)
 614                         break;
 615
 616                 while (read + input_event_size() <= count &&
 617                        evdev_fetch_next_event(client, &event)) {
 618
 619                         if (input_event_to_user(buffer + read, &event))
 620                                 return -EFAULT;
 621
 622                         read += input_event_size();
 623                 }
 624
 625                 if (read)
 626                         break;
 627
 628                 if (!(file->f_flags & O_NONBLOCK)) {
 629                         error = wait_event_interruptible(evdev->wait,
 630                                         client->packet_head != client->tail ||
 631                                         !evdev->exist || client->revoked);
 632                         if (error)
 633                                 return error;
 634                 }
 635         }
 636
 637         return read;
 638 }
 639
 640 /* No kernel lock - fine */
 641 static __poll_t evdev_poll(struct file *file, poll_table *wait)
 642 {
 643         struct evdev_client *client = file->private_data;
 644         struct evdev *evdev = client->evdev;
 645         __poll_t mask;
 646
 647         poll_wait(file, &evdev->wait, wait);
 648
 649         if (evdev->exist && !client->revoked)
 650                 mask = EPOLLOUT | EPOLLWRNORM;
 651         else
 652                 mask = EPOLLHUP | EPOLLERR;
 653
 654         if (client->packet_head != client->tail)
 655                 mask |= EPOLLIN | EPOLLRDNORM;
 656
 657         return mask;
 658 }
 659
 660 #ifdef CONFIG_COMPAT
 661
 662 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 663 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 664
 665 #ifdef __BIG_ENDIAN
 666 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 667                         unsigned int maxlen, void __user *p, int compat)
 668 {
 669         int len, i;
 670
 671         if (compat) {
 672                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 673                 if (len > maxlen)
 674                         len = maxlen;
 675
 676                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 677                         if (copy_to_user((compat_long_t __user *) p + i,
 678                                          (compat_long_t *) bits +
 679                                                 i + 1 - ((i % 2) << 1),
 680                                          sizeof(compat_long_t)))
 681                                 return -EFAULT;
 682         } else {
 683                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 684                 if (len > maxlen)
 685                         len = maxlen;
 686
 687                 if (copy_to_user(p, bits, len))
 688                         return -EFAULT;
 689         }
 690
 691         return len;
 692 }
 693
 694 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 695                           unsigned int maxlen, const void __user *p, int compat)
 696 {
 697         int len, i;
 698
 699         if (compat) {
 700                 if (maxlen % sizeof(compat_long_t))
 701                         return -EINVAL;
 702
 703                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 704                 if (len > maxlen)
 705                         len = maxlen;
 706
 707                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 708                         if (copy_from_user((compat_long_t *) bits +
 709                                                 i + 1 - ((i % 2) << 1),
 710                                            (compat_long_t __user *) p + i,
 711                                            sizeof(compat_long_t)))
 712                                 return -EFAULT;
 713                 if (i % 2)
 714                         *((compat_long_t *) bits + i - 1) = 0;
 715
 716         } else {
 717                 if (maxlen % sizeof(long))
 718                         return -EINVAL;
 719
 720                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 721                 if (len > maxlen)
 722                         len = maxlen;
 723
 724                 if (copy_from_user(bits, p, len))
 725                         return -EFAULT;
 726         }
 727
 728         return len;
 729 }
 730
 731 #else
 732
 733 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 734                         unsigned int maxlen, void __user *p, int compat)
 735 {
 736         int len = compat ?
 737                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 738                         BITS_TO_LONGS(maxbit) * sizeof(long);
 739
 740         if (len > maxlen)
 741                 len = maxlen;
 742
 743         return copy_to_user(p, bits, len) ? -EFAULT : len;
 744 }
 745
 746 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 747                           unsigned int maxlen, const void __user *p, int compat)
 748 {
 749         size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
 750         int len;
 751
 752         if (maxlen % chunk_size)
 753                 return -EINVAL;
 754
 755         len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
 756         len *= chunk_size;
 757         if (len > maxlen)
 758                 len = maxlen;
 759
 760         return copy_from_user(bits, p, len) ? -EFAULT : len;
 761 }
 762
 763 #endif /* __BIG_ENDIAN */
 764
 765 #else
 766
 767 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 768                         unsigned int maxlen, void __user *p, int compat)
 769 {
 770         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 771
 772         if (len > maxlen)
 773                 len = maxlen;
 774
 775         return copy_to_user(p, bits, len) ? -EFAULT : len;
 776 }
 777
 778 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 779                           unsigned int maxlen, const void __user *p, int compat)
 780 {
 781         int len;
 782
 783         if (maxlen % sizeof(long))
 784                 return -EINVAL;
 785
 786         len = BITS_TO_LONGS(maxbit) * sizeof(long);
 787         if (len > maxlen)
 788                 len = maxlen;
 789
 790         return copy_from_user(bits, p, len) ? -EFAULT : len;
 791 }
 792
 793 #endif /* CONFIG_COMPAT */
 794
 795 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 796 {
 797         int len;
 798
 799         if (!str)
 800                 return -ENOENT;
 801
 802         len = strlen(str) + 1;
 803         if (len > maxlen)
 804                 len = maxlen;
 805
 806         return copy_to_user(p, str, len) ? -EFAULT : len;
 807 }
 808
 809 static int handle_eviocgbit(struct input_dev *dev,
 810                             unsigned int type, unsigned int size,
 811                             void __user *p, int compat_mode)
 812 {
 813         unsigned long *bits;
 814         int len;
 815
 816         switch (type) {
 817
 818         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 819         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 820         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 821         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 822         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 823         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 824         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 825         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 826         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 827         default: return -EINVAL;
 828         }
 829
 830         return bits_to_user(bits, len, size, p, compat_mode);
 831 }
 832
 833 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 834 {
 835         struct input_keymap_entry ke = {
 836                 .len    = sizeof(unsigned int),
 837                 .flags  = 0,
 838         };
 839         int __user *ip = (int __user *)p;
 840         int error;
 841
 842         /* legacy case */
 843         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 844                 return -EFAULT;
 845
 846         error = input_get_keycode(dev, &ke);
 847         if (error)
 848                 return error;
 849
 850         if (put_user(ke.keycode, ip + 1))
 851                 return -EFAULT;
 852
 853         return 0;
 854 }
 855
 856 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 857 {
 858         struct input_keymap_entry ke;
 859         int error;
 860
 861         if (copy_from_user(&ke, p, sizeof(ke)))
 862                 return -EFAULT;
 863
 864         error = input_get_keycode(dev, &ke);
 865         if (error)
 866                 return error;
 867
 868         if (copy_to_user(p, &ke, sizeof(ke)))
 869                 return -EFAULT;
 870
 871         return 0;
 872 }
 873
 874 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 875 {
 876         struct input_keymap_entry ke = {
 877                 .len    = sizeof(unsigned int),
 878                 .flags  = 0,
 879         };
 880         int __user *ip = (int __user *)p;
 881
 882         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 883                 return -EFAULT;
 884
 885         if (get_user(ke.keycode, ip + 1))
 886                 return -EFAULT;
 887
 888         return input_set_keycode(dev, &ke);
 889 }
 890
 891 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 892 {
 893         struct input_keymap_entry ke;
 894
 895         if (copy_from_user(&ke, p, sizeof(ke)))
 896                 return -EFAULT;
 897
 898         if (ke.len > sizeof(ke.scancode))
 899                 return -EINVAL;
 900
 901         return input_set_keycode(dev, &ke);
 902 }
 903
 904 /*
 905  * If we transfer state to the user, we should flush all pending events
 906  * of the same type from the client's queue. Otherwise, they might end up
 907  * with duplicate events, which can screw up client's state tracking.
 908  * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
 909  * event so user-space will notice missing events.
 910  *
 911  * LOCKING:
 912  * We need to take event_lock before buffer_lock to avoid dead-locks. But we
 913  * need the even_lock only to guarantee consistent state. We can safely release
 914  * it while flushing the queue. This allows input-core to handle filters while
 915  * we flush the queue.
 916  */
 917 static int evdev_handle_get_val(struct evdev_client *client,
 918                                 struct input_dev *dev, unsigned int type,
 919                                 unsigned long *bits, unsigned int maxbit,
 920                                 unsigned int maxlen, void __user *p,
 921                                 int compat)
 922 {
 923         int ret;
 924         unsigned long *mem;
 925
 926         mem = bitmap_alloc(maxbit, GFP_KERNEL);
 927         if (!mem)
 928                 return -ENOMEM;
 929
 930         spin_lock_irq(&dev->event_lock);
 931         spin_lock(&client->buffer_lock);
 932
 933         bitmap_copy(mem, bits, maxbit);
 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         bitmap_free(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 = bitmap_zalloc(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                 bitmap_free(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         bitmap_free(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");