drivers/input/evdev.c

   1 /*
   2  * Event char devices, giving access to raw input device events.
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #define EVDEV_MINOR_BASE        64
  14 #define EVDEV_MINORS            32
  15 #define EVDEV_MIN_BUFFER_SIZE   64U
  16 #define EVDEV_BUF_PACKETS       8
  17
  18 #include <linux/poll.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/mm.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/input/mt.h>
  26 #include <linux/major.h>
  27 #include <linux/device.h>
  28 #include <linux/cdev.h>
  29 #include "input-compat.h"
  30
  31 enum evdev_clock_type {
  32         EV_CLK_REAL = 0,
  33         EV_CLK_MONO,
  34         EV_CLK_BOOT,
  35         EV_CLK_MAX
  36 };
  37
  38 struct evdev {
  39         int open;
  40         struct input_handle handle;
  41         wait_queue_head_t wait;
  42         struct evdev_client __rcu *grab;
  43         struct list_head client_list;
  44         spinlock_t client_lock; /* protects client_list */
  45         struct mutex mutex;
  46         struct device dev;
  47         struct cdev cdev;
  48         bool exist;
  49 };
  50
  51 struct evdev_client {
  52         unsigned int head;
  53         unsigned int tail;
  54         unsigned int packet_head; /* [future] position of the first element of next packet */
  55         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  56         struct fasync_struct *fasync;
  57         struct evdev *evdev;
  58         struct list_head node;
  59         unsigned int clk_type;
  60         bool revoked;
  61         unsigned long *evmasks[EV_CNT];
  62         unsigned int bufsize;
  63         struct input_event buffer[];
  64 };
  65
  66 static size_t evdev_get_mask_cnt(unsigned int type)
  67 {
  68         static const size_t counts[EV_CNT] = {
  69                 /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
  70                 [EV_SYN]        = EV_CNT,
  71                 [EV_KEY]        = KEY_CNT,
  72                 [EV_REL]        = REL_CNT,
  73                 [EV_ABS]        = ABS_CNT,
  74                 [EV_MSC]        = MSC_CNT,
  75                 [EV_SW]         = SW_CNT,
  76                 [EV_LED]        = LED_CNT,
  77                 [EV_SND]        = SND_CNT,
  78                 [EV_FF]         = FF_CNT,
  79         };
  80
  81         return (type < EV_CNT) ? counts[type] : 0;
  82 }
  83
  84 /* requires the buffer lock to be held */
  85 static bool __evdev_is_filtered(struct evdev_client *client,
  86                                 unsigned int type,
  87                                 unsigned int code)
  88 {
  89         unsigned long *mask;
  90         size_t cnt;
  91
  92         /* EV_SYN and unknown codes are never filtered */
  93         if (type == EV_SYN || type >= EV_CNT)
  94                 return false;
  95
  96         /* first test whether the type is filtered */
  97         mask = client->evmasks[0];
  98         if (mask && !test_bit(type, mask))
  99                 return true;
 100
 101         /* unknown values are never filtered */
 102         cnt = evdev_get_mask_cnt(type);
 103         if (!cnt || code >= cnt)
 104                 return false;
 105
 106         mask = client->evmasks[type];
 107         return mask && !test_bit(code, mask);
 108 }
 109
 110 /* flush queued events of type @type, caller must hold client->buffer_lock */
 111 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
 112 {
 113         unsigned int i, head, num;
 114         unsigned int mask = client->bufsize - 1;
 115         bool is_report;
 116         struct input_event *ev;
 117
 118         BUG_ON(type == EV_SYN);
 119
 120         head = client->tail;
 121         client->packet_head = client->tail;
 122
 123         /* init to 1 so a leading SYN_REPORT will not be dropped */
 124         num = 1;
 125
 126         for (i = client->tail; i != client->head; i = (i + 1) & mask) {
 127                 ev = &client->buffer[i];
 128                 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
 129
 130                 if (ev->type == type) {
 131                         /* drop matched entry */
 132                         continue;
 133                 } else if (is_report && !num) {
 134                         /* drop empty SYN_REPORT groups */
 135                         continue;
 136                 } else if (head != i) {
 137                         /* move entry to fill the gap */
 138                         client->buffer[head] = *ev;
 139                 }
 140
 141                 num++;
 142                 head = (head + 1) & mask;
 143
 144                 if (is_report) {
 145                         num = 0;
 146                         client->packet_head = head;
 147                 }
 148         }
 149
 150         client->head = head;
 151 }
 152
 153 static void __evdev_queue_syn_dropped(struct evdev_client *client)
 154 {
 155         struct input_event ev;
 156         ktime_t time;
 157         struct timespec64 ts;
 158
 159         time = client->clk_type == EV_CLK_REAL ?
 160                         ktime_get_real() :
 161                         client->clk_type == EV_CLK_MONO ?
 162                                 ktime_get() :
 163                                 ktime_get_boottime();
 164
 165         ts = ktime_to_timespec64(time);
 166         ev.input_event_sec = ts.tv_sec;
 167         ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 168         ev.type = EV_SYN;
 169         ev.code = SYN_DROPPED;
 170         ev.value = 0;
 171
 172         client->buffer[client->head++] = ev;
 173         client->head &= client->bufsize - 1;
 174
 175         if (unlikely(client->head == client->tail)) {
 176                 /* drop queue but keep our SYN_DROPPED event */
 177                 client->tail = (client->head - 1) & (client->bufsize - 1);
 178                 client->packet_head = client->tail;
 179         }
 180 }
 181
 182 static void evdev_queue_syn_dropped(struct evdev_client *client)
 183 {
 184         unsigned long flags;
 185
 186         spin_lock_irqsave(&client->buffer_lock, flags);
 187         __evdev_queue_syn_dropped(client);
 188         spin_unlock_irqrestore(&client->buffer_lock, flags);
 189 }
 190
 191 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
 192 {
 193         unsigned long flags;
 194         unsigned int clk_type;
 195
 196         switch (clkid) {
 197
 198         case CLOCK_REALTIME:
 199                 clk_type = EV_CLK_REAL;
 200                 break;
 201         case CLOCK_MONOTONIC:
 202                 clk_type = EV_CLK_MONO;
 203                 break;
 204         case CLOCK_BOOTTIME:
 205                 clk_type = EV_CLK_BOOT;
 206                 break;
 207         default:
 208                 return -EINVAL;
 209         }
 210
 211         if (client->clk_type != clk_type) {
 212                 client->clk_type = clk_type;
 213
 214                 /*
 215                  * Flush pending events and queue SYN_DROPPED event,
 216                  * but only if the queue is not empty.
 217                  */
 218                 spin_lock_irqsave(&client->buffer_lock, flags);
 219
 220                 if (client->head != client->tail) {
 221                         client->packet_head = client->head = client->tail;
 222                         __evdev_queue_syn_dropped(client);
 223                 }
 224
 225                 spin_unlock_irqrestore(&client->buffer_lock, flags);
 226         }
 227
 228         return 0;
 229 }
 230
 231 static void __pass_event(struct evdev_client *client,
 232                          const struct input_event *event)
 233 {
 234         client->buffer[client->head++] = *event;
 235         client->head &= client->bufsize - 1;
 236
 237         if (unlikely(client->head == client->tail)) {
 238                 /*
 239                  * This effectively "drops" all unconsumed events, leaving
 240                  * EV_SYN/SYN_DROPPED plus the newest event in the queue.
 241                  */
 242                 client->tail = (client->head - 2) & (client->bufsize - 1);
 243
 244                 client->buffer[client->tail].input_event_sec =
 245                                                 event->input_event_sec;
 246                 client->buffer[client->tail].input_event_usec =
 247                                                 event->input_event_usec;
 248                 client->buffer[client->tail].type = EV_SYN;
 249                 client->buffer[client->tail].code = SYN_DROPPED;
 250                 client->buffer[client->tail].value = 0;
 251
 252                 client->packet_head = client->tail;
 253         }
 254
 255         if (event->type == EV_SYN && event->code == SYN_REPORT) {
 256                 client->packet_head = client->head;
 257                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
 258         }
 259 }
 260
 261 static void evdev_pass_values(struct evdev_client *client,
 262                         const struct input_value *vals, unsigned int count,
 263                         ktime_t *ev_time)
 264 {
 265         struct evdev *evdev = client->evdev;
 266         const struct input_value *v;
 267         struct input_event event;
 268         struct timespec64 ts;
 269         bool wakeup = false;
 270
 271         if (client->revoked)
 272                 return;
 273
 274         ts = ktime_to_timespec64(ev_time[client->clk_type]);
 275         event.input_event_sec = ts.tv_sec;
 276         event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
 277
 278         /* Interrupts are disabled, just acquire the lock. */
 279         spin_lock(&client->buffer_lock);
 280
 281         for (v = vals; v != vals + count; v++) {
 282                 if (__evdev_is_filtered(client, v->type, v->code))
 283                         continue;
 284
 285                 if (v->type == EV_SYN && v->code == SYN_REPORT) {
 286                         /* drop empty SYN_REPORT */
 287                         if (client->packet_head == client->head)
 288                                 continue;
 289
 290                         wakeup = true;
 291                 }
 292
 293                 event.type = v->type;
 294                 event.code = v->code;
 295                 event.value = v->value;
 296                 __pass_event(client, &event);
 297         }
 298
 299         spin_unlock(&client->buffer_lock);
 300
 301         if (wakeup)
 302                 wake_up_interruptible(&evdev->wait);
 303 }
 304
 305 /*
 306  * Pass incoming events to all connected clients.
 307  */
 308 static void evdev_events(struct input_handle *handle,
 309                          const struct input_value *vals, unsigned int count)
 310 {
 311         struct evdev *evdev = handle->private;
 312         struct evdev_client *client;
 313         ktime_t ev_time[EV_CLK_MAX];
 314
 315         ev_time[EV_CLK_MONO] = ktime_get();
 316         ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
 317         ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
 318                                                  TK_OFFS_BOOT);
 319
 320         rcu_read_lock();
 321
 322         client = rcu_dereference(evdev->grab);
 323
 324         if (client)
 325                 evdev_pass_values(client, vals, count, ev_time);
 326         else
 327                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 328                         evdev_pass_values(client, vals, count, ev_time);
 329
 330         rcu_read_unlock();
 331 }
 332
 333 /*
 334  * Pass incoming event to all connected clients.
 335  */
 336 static void evdev_event(struct input_handle *handle,
 337                         unsigned int type, unsigned int code, int value)
 338 {
 339         struct input_value vals[] = { { type, code, value } };
 340
 341         evdev_events(handle, vals, 1);
 342 }
 343
 344 static int evdev_fasync(int fd, struct file *file, int on)
 345 {
 346         struct evdev_client *client = file->private_data;
 347
 348         return fasync_helper(fd, file, on, &client->fasync);
 349 }
 350
 351 static int evdev_flush(struct file *file, fl_owner_t id)
 352 {
 353         struct evdev_client *client = file->private_data;
 354         struct evdev *evdev = client->evdev;
 355
 356         mutex_lock(&evdev->mutex);
 357
 358         if (evdev->exist && !client->revoked)
 359                 input_flush_device(&evdev->handle, file);
 360
 361         mutex_unlock(&evdev->mutex);
 362         return 0;
 363 }
 364
 365 static void evdev_free(struct device *dev)
 366 {
 367         struct evdev *evdev = container_of(dev, struct evdev, dev);
 368
 369         input_put_device(evdev->handle.dev);
 370         kfree(evdev);
 371 }
 372
 373 /*
 374  * Grabs an event device (along with underlying input device).
 375  * This function is called with evdev->mutex taken.
 376  */
 377 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 378 {
 379         int error;
 380
 381         if (evdev->grab)
 382                 return -EBUSY;
 383
 384         error = input_grab_device(&evdev->handle);
 385         if (error)
 386                 return error;
 387
 388         rcu_assign_pointer(evdev->grab, client);
 389
 390         return 0;
 391 }
 392
 393 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 394 {
 395         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 396                                         lockdep_is_held(&evdev->mutex));
 397
 398         if (grab != client)
 399                 return  -EINVAL;
 400
 401         rcu_assign_pointer(evdev->grab, NULL);
 402         synchronize_rcu();
 403         input_release_device(&evdev->handle);
 404
 405         return 0;
 406 }
 407
 408 static void evdev_attach_client(struct evdev *evdev,
 409                                 struct evdev_client *client)
 410 {
 411         spin_lock(&evdev->client_lock);
 412         list_add_tail_rcu(&client->node, &evdev->client_list);
 413         spin_unlock(&evdev->client_lock);
 414 }
 415
 416 static void evdev_detach_client(struct evdev *evdev,
 417                                 struct evdev_client *client)
 418 {
 419         spin_lock(&evdev->client_lock);
 420         list_del_rcu(&client->node);
 421         spin_unlock(&evdev->client_lock);
 422         synchronize_rcu();
 423 }
 424
 425 static int evdev_open_device(struct evdev *evdev)
 426 {
 427         int retval;
 428
 429         retval = mutex_lock_interruptible(&evdev->mutex);
 430         if (retval)
 431                 return retval;
 432
 433         if (!evdev->exist)
 434                 retval = -ENODEV;
 435         else if (!evdev->open++) {
 436                 retval = input_open_device(&evdev->handle);
 437                 if (retval)
 438                         evdev->open--;
 439         }
 440
 441         mutex_unlock(&evdev->mutex);
 442         return retval;
 443 }
 444
 445 static void evdev_close_device(struct evdev *evdev)
 446 {
 447         mutex_lock(&evdev->mutex);
 448
 449         if (evdev->exist && !--evdev->open)
 450                 input_close_device(&evdev->handle);
 451
 452         mutex_unlock(&evdev->mutex);
 453 }
 454
 455 /*
 456  * Wake up users waiting for IO so they can disconnect from
 457  * dead device.
 458  */
 459 static void evdev_hangup(struct evdev *evdev)
 460 {
 461         struct evdev_client *client;
 462
 463         spin_lock(&evdev->client_lock);
 464         list_for_each_entry(client, &evdev->client_list, node)
 465                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 466         spin_unlock(&evdev->client_lock);
 467
 468         wake_up_interruptible(&evdev->wait);
 469 }
 470
 471 static int evdev_release(struct inode *inode, struct file *file)
 472 {
 473         struct evdev_client *client = file->private_data;
 474         struct evdev *evdev = client->evdev;
 475         unsigned int i;
 476
 477         mutex_lock(&evdev->mutex);
 478         evdev_ungrab(evdev, client);
 479         mutex_unlock(&evdev->mutex);
 480
 481         evdev_detach_client(evdev, client);
 482
 483         for (i = 0; i < EV_CNT; ++i)
 484                 bitmap_free(client->evmasks[i]);
 485
 486         kvfree(client);
 487
 488         evdev_close_device(evdev);
 489
 490         return 0;
 491 }
 492
 493 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 494 {
 495         unsigned int n_events =
 496                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 497                     EVDEV_MIN_BUFFER_SIZE);
 498
 499         return roundup_pow_of_two(n_events);
 500 }
 501
 502 static int evdev_open(struct inode *inode, struct file *file)
 503 {
 504         struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
 505         unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 506         struct evdev_client *client;
 507         int error;
 508
 509         client = kzalloc(struct_size(client, buffer, bufsize),
 510                          GFP_KERNEL | __GFP_NOWARN);
 511         if (!client)
 512                 client = vzalloc(struct_size(client, buffer, bufsize));
 513         if (!client)
 514                 return -ENOMEM;
 515
 516         client->bufsize = bufsize;
 517         spin_lock_init(&client->buffer_lock);
 518         client->evdev = evdev;
 519         evdev_attach_client(evdev, client);
 520
 521         error = evdev_open_device(evdev);
 522         if (error)
 523                 goto err_free_client;
 524
 525         file->private_data = client;
 526         nonseekable_open(inode, file);
 527
 528         return 0;
 529
 530  err_free_client:
 531         evdev_detach_client(evdev, client);
 532         kvfree(client);
 533         return error;
 534 }
 535
 536 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 537                            size_t count, loff_t *ppos)
 538 {
 539         struct evdev_client *client = file->private_data;
 540         struct evdev *evdev = client->evdev;
 541         struct input_event event;
 542         int retval = 0;
 543
 544         if (count != 0 && count < input_event_size())
 545                 return -EINVAL;
 546
 547         retval = mutex_lock_interruptible(&evdev->mutex);
 548         if (retval)
 549                 return retval;
 550
 551         if (!evdev->exist || client->revoked) {
 552                 retval = -ENODEV;
 553                 goto out;
 554         }
 555
 556         while (retval + input_event_size() <= count) {
 557
 558                 if (input_event_from_user(buffer + retval, &event)) {
 559                         retval = -EFAULT;
 560                         goto out;
 561                 }
 562                 retval += input_event_size();
 563
 564                 input_inject_event(&evdev->handle,
 565                                    event.type, event.code, event.value);
 566                 cond_resched();
 567         }
 568
 569  out:
 570         mutex_unlock(&evdev->mutex);
 571         return retval;
 572 }
 573
 574 static int evdev_fetch_next_event(struct evdev_client *client,
 575                                   struct input_event *event)
 576 {
 577         int have_event;
 578
 579         spin_lock_irq(&client->buffer_lock);
 580
 581         have_event = client->packet_head != client->tail;
 582         if (have_event) {
 583                 *event = client->buffer[client->tail++];
 584                 client->tail &= client->bufsize - 1;
 585         }
 586
 587         spin_unlock_irq(&client->buffer_lock);
 588
 589         return have_event;
 590 }
 591
 592 static ssize_t evdev_read(struct file *file, char __user *buffer,
 593                           size_t count, loff_t *ppos)
 594 {
 595         struct evdev_client *client = file->private_data;
 596         struct evdev *evdev = client->evdev;
 597         struct input_event event;
 598         size_t read = 0;
 599         int error;
 600
 601         if (count != 0 && count < input_event_size())
 602                 return -EINVAL;
 603
 604         for (;;) {
 605                 if (!evdev->exist || client->revoked)
 606                         return -ENODEV;
 607
 608                 if (client->packet_head == client->tail &&
 609                     (file->f_flags & O_NONBLOCK))
 610                         return -EAGAIN;
 611
 612                 /*
 613                  * count == 0 is special - no IO is done but we check
 614                  * for error conditions (see above).
 615                  */
 616                 if (count == 0)
 617                         break;
 618
 619                 while (read + input_event_size() <= count &&
 620                        evdev_fetch_next_event(client, &event)) {
 621
 622                         if (input_event_to_user(buffer + read, &event))
 623                                 return -EFAULT;
 624
 625                         read += input_event_size();
 626                 }
 627
 628                 if (read)
 629                         break;
 630
 631                 if (!(file->f_flags & O_NONBLOCK)) {
 632                         error = wait_event_interruptible(evdev->wait,
 633                                         client->packet_head != client->tail ||
 634                                         !evdev->exist || client->revoked);
 635                         if (error)
 636                                 return error;
 637                 }
 638         }
 639
 640         return read;
 641 }
 642
 643 /* No kernel lock - fine */
 644 static __poll_t evdev_poll(struct file *file, poll_table *wait)
 645 {
 646         struct evdev_client *client = file->private_data;
 647         struct evdev *evdev = client->evdev;
 648         __poll_t mask;
 649
 650         poll_wait(file, &evdev->wait, wait);
 651
 652         if (evdev->exist && !client->revoked)
 653                 mask = EPOLLOUT | EPOLLWRNORM;
 654         else
 655                 mask = EPOLLHUP | EPOLLERR;
 656
 657         if (client->packet_head != client->tail)
 658                 mask |= EPOLLIN | EPOLLRDNORM;
 659
 660         return mask;
 661 }
 662
 663 #ifdef CONFIG_COMPAT
 664
 665 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 666 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 667
 668 #ifdef __BIG_ENDIAN
 669 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 670                         unsigned int maxlen, void __user *p, int compat)
 671 {
 672         int len, i;
 673
 674         if (compat) {
 675                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 676                 if (len > maxlen)
 677                         len = maxlen;
 678
 679                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 680                         if (copy_to_user((compat_long_t __user *) p + i,
 681                                          (compat_long_t *) bits +
 682                                                 i + 1 - ((i % 2) << 1),
 683                                          sizeof(compat_long_t)))
 684                                 return -EFAULT;
 685         } else {
 686                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 687                 if (len > maxlen)
 688                         len = maxlen;
 689
 690                 if (copy_to_user(p, bits, len))
 691                         return -EFAULT;
 692         }
 693
 694         return len;
 695 }
 696
 697 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 698                           unsigned int maxlen, const void __user *p, int compat)
 699 {
 700         int len, i;
 701
 702         if (compat) {
 703                 if (maxlen % sizeof(compat_long_t))
 704                         return -EINVAL;
 705
 706                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 707                 if (len > maxlen)
 708                         len = maxlen;
 709
 710                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 711                         if (copy_from_user((compat_long_t *) bits +
 712                                                 i + 1 - ((i % 2) << 1),
 713                                            (compat_long_t __user *) p + i,
 714                                            sizeof(compat_long_t)))
 715                                 return -EFAULT;
 716                 if (i % 2)
 717                         *((compat_long_t *) bits + i - 1) = 0;
 718
 719         } else {
 720                 if (maxlen % sizeof(long))
 721                         return -EINVAL;
 722
 723                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 724                 if (len > maxlen)
 725                         len = maxlen;
 726
 727                 if (copy_from_user(bits, p, len))
 728                         return -EFAULT;
 729         }
 730
 731         return len;
 732 }
 733
 734 #else
 735
 736 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 737                         unsigned int maxlen, void __user *p, int compat)
 738 {
 739         int len = compat ?
 740                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 741                         BITS_TO_LONGS(maxbit) * sizeof(long);
 742
 743         if (len > maxlen)
 744                 len = maxlen;
 745
 746         return copy_to_user(p, bits, len) ? -EFAULT : len;
 747 }
 748
 749 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 750                           unsigned int maxlen, const void __user *p, int compat)
 751 {
 752         size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
 753         int len;
 754
 755         if (maxlen % chunk_size)
 756                 return -EINVAL;
 757
 758         len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
 759         len *= chunk_size;
 760         if (len > maxlen)
 761                 len = maxlen;
 762
 763         return copy_from_user(bits, p, len) ? -EFAULT : len;
 764 }
 765
 766 #endif /* __BIG_ENDIAN */
 767
 768 #else
 769
 770 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 771                         unsigned int maxlen, void __user *p, int compat)
 772 {
 773         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 774
 775         if (len > maxlen)
 776                 len = maxlen;
 777
 778         return copy_to_user(p, bits, len) ? -EFAULT : len;
 779 }
 780
 781 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 782                           unsigned int maxlen, const void __user *p, int compat)
 783 {
 784         int len;
 785
 786         if (maxlen % sizeof(long))
 787                 return -EINVAL;
 788
 789         len = BITS_TO_LONGS(maxbit) * sizeof(long);
 790         if (len > maxlen)
 791                 len = maxlen;
 792
 793         return copy_from_user(bits, p, len) ? -EFAULT : len;
 794 }
 795
 796 #endif /* CONFIG_COMPAT */
 797
 798 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 799 {
 800         int len;
 801
 802         if (!str)
 803                 return -ENOENT;
 804
 805         len = strlen(str) + 1;
 806         if (len > maxlen)
 807                 len = maxlen;
 808
 809         return copy_to_user(p, str, len) ? -EFAULT : len;
 810 }
 811
 812 static int handle_eviocgbit(struct input_dev *dev,
 813                             unsigned int type, unsigned int size,
 814                             void __user *p, int compat_mode)
 815 {
 816         unsigned long *bits;
 817         int len;
 818
 819         switch (type) {
 820
 821         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 822         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 823         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 824         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 825         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 826         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 827         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 828         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 829         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 830         default: return -EINVAL;
 831         }
 832
 833         return bits_to_user(bits, len, size, p, compat_mode);
 834 }
 835
 836 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 837 {
 838         struct input_keymap_entry ke = {
 839                 .len    = sizeof(unsigned int),
 840                 .flags  = 0,
 841         };
 842         int __user *ip = (int __user *)p;
 843         int error;
 844
 845         /* legacy case */
 846         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 847                 return -EFAULT;
 848
 849         error = input_get_keycode(dev, &ke);
 850         if (error)
 851                 return error;
 852
 853         if (put_user(ke.keycode, ip + 1))
 854                 return -EFAULT;
 855
 856         return 0;
 857 }
 858
 859 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 860 {
 861         struct input_keymap_entry ke;
 862         int error;
 863
 864         if (copy_from_user(&ke, p, sizeof(ke)))
 865                 return -EFAULT;
 866
 867         error = input_get_keycode(dev, &ke);
 868         if (error)
 869                 return error;
 870
 871         if (copy_to_user(p, &ke, sizeof(ke)))
 872                 return -EFAULT;
 873
 874         return 0;
 875 }
 876
 877 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 878 {
 879         struct input_keymap_entry ke = {
 880                 .len    = sizeof(unsigned int),
 881                 .flags  = 0,
 882         };
 883         int __user *ip = (int __user *)p;
 884
 885         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 886                 return -EFAULT;
 887
 888         if (get_user(ke.keycode, ip + 1))
 889                 return -EFAULT;
 890
 891         return input_set_keycode(dev, &ke);
 892 }
 893
 894 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 895 {
 896         struct input_keymap_entry ke;
 897
 898         if (copy_from_user(&ke, p, sizeof(ke)))
 899                 return -EFAULT;
 900
 901         if (ke.len > sizeof(ke.scancode))
 902                 return -EINVAL;
 903
 904         return input_set_keycode(dev, &ke);
 905 }
 906
 907 /*
 908  * If we transfer state to the user, we should flush all pending events
 909  * of the same type from the client's queue. Otherwise, they might end up
 910  * with duplicate events, which can screw up client's state tracking.
 911  * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
 912  * event so user-space will notice missing events.
 913  *
 914  * LOCKING:
 915  * We need to take event_lock before buffer_lock to avoid dead-locks. But we
 916  * need the even_lock only to guarantee consistent state. We can safely release
 917  * it while flushing the queue. This allows input-core to handle filters while
 918  * we flush the queue.
 919  */
 920 static int evdev_handle_get_val(struct evdev_client *client,
 921                                 struct input_dev *dev, unsigned int type,
 922                                 unsigned long *bits, unsigned int maxbit,
 923                                 unsigned int maxlen, void __user *p,
 924                                 int compat)
 925 {
 926         int ret;
 927         unsigned long *mem;
 928
 929         mem = bitmap_alloc(maxbit, GFP_KERNEL);
 930         if (!mem)
 931                 return -ENOMEM;
 932
 933         spin_lock_irq(&dev->event_lock);
 934         spin_lock(&client->buffer_lock);
 935
 936         bitmap_copy(mem, bits, maxbit);
 937
 938         spin_unlock(&dev->event_lock);
 939
 940         __evdev_flush_queue(client, type);
 941
 942         spin_unlock_irq(&client->buffer_lock);
 943
 944         ret = bits_to_user(mem, maxbit, maxlen, p, compat);
 945         if (ret < 0)
 946                 evdev_queue_syn_dropped(client);
 947
 948         bitmap_free(mem);
 949
 950         return ret;
 951 }
 952
 953 static int evdev_handle_mt_request(struct input_dev *dev,
 954                                    unsigned int size,
 955                                    int __user *ip)
 956 {
 957         const struct input_mt *mt = dev->mt;
 958         unsigned int code;
 959         int max_slots;
 960         int i;
 961
 962         if (get_user(code, &ip[0]))
 963                 return -EFAULT;
 964         if (!mt || !input_is_mt_value(code))
 965                 return -EINVAL;
 966
 967         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 968         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 969                 int value = input_mt_get_value(&mt->slots[i], code);
 970                 if (put_user(value, &ip[1 + i]))
 971                         return -EFAULT;
 972         }
 973
 974         return 0;
 975 }
 976
 977 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
 978                         struct file *file)
 979 {
 980         client->revoked = true;
 981         evdev_ungrab(evdev, client);
 982         input_flush_device(&evdev->handle, file);
 983         wake_up_interruptible(&evdev->wait);
 984
 985         return 0;
 986 }
 987
 988 /* must be called with evdev-mutex held */
 989 static int evdev_set_mask(struct evdev_client *client,
 990                           unsigned int type,
 991                           const void __user *codes,
 992                           u32 codes_size,
 993                           int compat)
 994 {
 995         unsigned long flags, *mask, *oldmask;
 996         size_t cnt;
 997         int error;
 998
 999         /* we allow unknown types and 'codes_size > size' for forward-compat */
1000         cnt = evdev_get_mask_cnt(type);
1001         if (!cnt)
1002                 return 0;
1003
1004         mask = bitmap_zalloc(cnt, GFP_KERNEL);
1005         if (!mask)
1006                 return -ENOMEM;
1007
1008         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1009         if (error < 0) {
1010                 bitmap_free(mask);
1011                 return error;
1012         }
1013
1014         spin_lock_irqsave(&client->buffer_lock, flags);
1015         oldmask = client->evmasks[type];
1016         client->evmasks[type] = mask;
1017         spin_unlock_irqrestore(&client->buffer_lock, flags);
1018
1019         bitmap_free(oldmask);
1020
1021         return 0;
1022 }
1023
1024 /* must be called with evdev-mutex held */
1025 static int evdev_get_mask(struct evdev_client *client,
1026                           unsigned int type,
1027                           void __user *codes,
1028                           u32 codes_size,
1029                           int compat)
1030 {
1031         unsigned long *mask;
1032         size_t cnt, size, xfer_size;
1033         int i;
1034         int error;
1035
1036         /* we allow unknown types and 'codes_size > size' for forward-compat */
1037         cnt = evdev_get_mask_cnt(type);
1038         size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1039         xfer_size = min_t(size_t, codes_size, size);
1040
1041         if (cnt > 0) {
1042                 mask = client->evmasks[type];
1043                 if (mask) {
1044                         error = bits_to_user(mask, cnt - 1,
1045                                              xfer_size, codes, compat);
1046                         if (error < 0)
1047                                 return error;
1048                 } else {
1049                         /* fake mask with all bits set */
1050                         for (i = 0; i < xfer_size; i++)
1051                                 if (put_user(0xffU, (u8 __user *)codes + i))
1052                                         return -EFAULT;
1053                 }
1054         }
1055
1056         if (xfer_size < codes_size)
1057                 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1058                         return -EFAULT;
1059
1060         return 0;
1061 }
1062
1063 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1064                            void __user *p, int compat_mode)
1065 {
1066         struct evdev_client *client = file->private_data;
1067         struct evdev *evdev = client->evdev;
1068         struct input_dev *dev = evdev->handle.dev;
1069         struct input_absinfo abs;
1070         struct input_mask mask;
1071         struct ff_effect effect;
1072         int __user *ip = (int __user *)p;
1073         unsigned int i, t, u, v;
1074         unsigned int size;
1075         int error;
1076
1077         /* First we check for fixed-length commands */
1078         switch (cmd) {
1079
1080         case EVIOCGVERSION:
1081                 return put_user(EV_VERSION, ip);
1082
1083         case EVIOCGID:
1084                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1085                         return -EFAULT;
1086                 return 0;
1087
1088         case EVIOCGREP:
1089                 if (!test_bit(EV_REP, dev->evbit))
1090                         return -ENOSYS;
1091                 if (put_user(dev->rep[REP_DELAY], ip))
1092                         return -EFAULT;
1093                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1094                         return -EFAULT;
1095                 return 0;
1096
1097         case EVIOCSREP:
1098                 if (!test_bit(EV_REP, dev->evbit))
1099                         return -ENOSYS;
1100                 if (get_user(u, ip))
1101                         return -EFAULT;
1102                 if (get_user(v, ip + 1))
1103                         return -EFAULT;
1104
1105                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1106                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1107
1108                 return 0;
1109
1110         case EVIOCRMFF:
1111                 return input_ff_erase(dev, (int)(unsigned long) p, file);
1112
1113         case EVIOCGEFFECTS:
1114                 i = test_bit(EV_FF, dev->evbit) ?
1115                                 dev->ff->max_effects : 0;
1116                 if (put_user(i, ip))
1117                         return -EFAULT;
1118                 return 0;
1119
1120         case EVIOCGRAB:
1121                 if (p)
1122                         return evdev_grab(evdev, client);
1123                 else
1124                         return evdev_ungrab(evdev, client);
1125
1126         case EVIOCREVOKE:
1127                 if (p)
1128                         return -EINVAL;
1129                 else
1130                         return evdev_revoke(evdev, client, file);
1131
1132         case EVIOCGMASK: {
1133                 void __user *codes_ptr;
1134
1135                 if (copy_from_user(&mask, p, sizeof(mask)))
1136                         return -EFAULT;
1137
1138                 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1139                 return evdev_get_mask(client,
1140                                       mask.type, codes_ptr, mask.codes_size,
1141                                       compat_mode);
1142         }
1143
1144         case EVIOCSMASK: {
1145                 const void __user *codes_ptr;
1146
1147                 if (copy_from_user(&mask, p, sizeof(mask)))
1148                         return -EFAULT;
1149
1150                 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1151                 return evdev_set_mask(client,
1152                                       mask.type, codes_ptr, mask.codes_size,
1153                                       compat_mode);
1154         }
1155
1156         case EVIOCSCLOCKID:
1157                 if (copy_from_user(&i, p, sizeof(unsigned int)))
1158                         return -EFAULT;
1159
1160                 return evdev_set_clk_type(client, i);
1161
1162         case EVIOCGKEYCODE:
1163                 return evdev_handle_get_keycode(dev, p);
1164
1165         case EVIOCSKEYCODE:
1166                 return evdev_handle_set_keycode(dev, p);
1167
1168         case EVIOCGKEYCODE_V2:
1169                 return evdev_handle_get_keycode_v2(dev, p);
1170
1171         case EVIOCSKEYCODE_V2:
1172                 return evdev_handle_set_keycode_v2(dev, p);
1173         }
1174
1175         size = _IOC_SIZE(cmd);
1176
1177         /* Now check variable-length commands */
1178 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1179         switch (EVIOC_MASK_SIZE(cmd)) {
1180
1181         case EVIOCGPROP(0):
1182                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1183                                     size, p, compat_mode);
1184
1185         case EVIOCGMTSLOTS(0):
1186                 return evdev_handle_mt_request(dev, size, ip);
1187
1188         case EVIOCGKEY(0):
1189                 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1190                                             KEY_MAX, size, p, compat_mode);
1191
1192         case EVIOCGLED(0):
1193                 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1194                                             LED_MAX, size, p, compat_mode);
1195
1196         case EVIOCGSND(0):
1197                 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1198                                             SND_MAX, size, p, compat_mode);
1199
1200         case EVIOCGSW(0):
1201                 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1202                                             SW_MAX, size, p, compat_mode);
1203
1204         case EVIOCGNAME(0):
1205                 return str_to_user(dev->name, size, p);
1206
1207         case EVIOCGPHYS(0):
1208                 return str_to_user(dev->phys, size, p);
1209
1210         case EVIOCGUNIQ(0):
1211                 return str_to_user(dev->uniq, size, p);
1212
1213         case EVIOC_MASK_SIZE(EVIOCSFF):
1214                 if (input_ff_effect_from_user(p, size, &effect))
1215                         return -EFAULT;
1216
1217                 error = input_ff_upload(dev, &effect, file);
1218                 if (error)
1219                         return error;
1220
1221                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1222                         return -EFAULT;
1223
1224                 return 0;
1225         }
1226
1227         /* Multi-number variable-length handlers */
1228         if (_IOC_TYPE(cmd) != 'E')
1229                 return -EINVAL;
1230
1231         if (_IOC_DIR(cmd) == _IOC_READ) {
1232
1233                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1234                         return handle_eviocgbit(dev,
1235                                                 _IOC_NR(cmd) & EV_MAX, size,
1236                                                 p, compat_mode);
1237
1238                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1239
1240                         if (!dev->absinfo)
1241                                 return -EINVAL;
1242
1243                         t = _IOC_NR(cmd) & ABS_MAX;
1244                         abs = dev->absinfo[t];
1245
1246                         if (copy_to_user(p, &abs, min_t(size_t,
1247                                         size, sizeof(struct input_absinfo))))
1248                                 return -EFAULT;
1249
1250                         return 0;
1251                 }
1252         }
1253
1254         if (_IOC_DIR(cmd) == _IOC_WRITE) {
1255
1256                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1257
1258                         if (!dev->absinfo)
1259                                 return -EINVAL;
1260
1261                         t = _IOC_NR(cmd) & ABS_MAX;
1262
1263                         if (copy_from_user(&abs, p, min_t(size_t,
1264                                         size, sizeof(struct input_absinfo))))
1265                                 return -EFAULT;
1266
1267                         if (size < sizeof(struct input_absinfo))
1268                                 abs.resolution = 0;
1269
1270                         /* We can't change number of reserved MT slots */
1271                         if (t == ABS_MT_SLOT)
1272                                 return -EINVAL;
1273
1274                         /*
1275                          * Take event lock to ensure that we are not
1276                          * changing device parameters in the middle
1277                          * of event.
1278                          */
1279                         spin_lock_irq(&dev->event_lock);
1280                         dev->absinfo[t] = abs;
1281                         spin_unlock_irq(&dev->event_lock);
1282
1283                         return 0;
1284                 }
1285         }
1286
1287         return -EINVAL;
1288 }
1289
1290 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1291                                 void __user *p, int compat_mode)
1292 {
1293         struct evdev_client *client = file->private_data;
1294         struct evdev *evdev = client->evdev;
1295         int retval;
1296
1297         retval = mutex_lock_interruptible(&evdev->mutex);
1298         if (retval)
1299                 return retval;
1300
1301         if (!evdev->exist || client->revoked) {
1302                 retval = -ENODEV;
1303                 goto out;
1304         }
1305
1306         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1307
1308  out:
1309         mutex_unlock(&evdev->mutex);
1310         return retval;
1311 }
1312
1313 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1314 {
1315         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1316 }
1317
1318 #ifdef CONFIG_COMPAT
1319 static long evdev_ioctl_compat(struct file *file,
1320                                 unsigned int cmd, unsigned long arg)
1321 {
1322         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1323 }
1324 #endif
1325
1326 static const struct file_operations evdev_fops = {
1327         .owner          = THIS_MODULE,
1328         .read           = evdev_read,
1329         .write          = evdev_write,
1330         .poll           = evdev_poll,
1331         .open           = evdev_open,
1332         .release        = evdev_release,
1333         .unlocked_ioctl = evdev_ioctl,
1334 #ifdef CONFIG_COMPAT
1335         .compat_ioctl   = evdev_ioctl_compat,
1336 #endif
1337         .fasync         = evdev_fasync,
1338         .flush          = evdev_flush,
1339         .llseek         = no_llseek,
1340 };
1341
1342 /*
1343  * Mark device non-existent. This disables writes, ioctls and
1344  * prevents new users from opening the device. Already posted
1345  * blocking reads will stay, however new ones will fail.
1346  */
1347 static void evdev_mark_dead(struct evdev *evdev)
1348 {
1349         mutex_lock(&evdev->mutex);
1350         evdev->exist = false;
1351         mutex_unlock(&evdev->mutex);
1352 }
1353
1354 static void evdev_cleanup(struct evdev *evdev)
1355 {
1356         struct input_handle *handle = &evdev->handle;
1357
1358         evdev_mark_dead(evdev);
1359         evdev_hangup(evdev);
1360
1361         /* evdev is marked dead so no one else accesses evdev->open */
1362         if (evdev->open) {
1363                 input_flush_device(handle, NULL);
1364                 input_close_device(handle);
1365         }
1366 }
1367
1368 /*
1369  * Create new evdev device. Note that input core serializes calls
1370  * to connect and disconnect.
1371  */
1372 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1373                          const struct input_device_id *id)
1374 {
1375         struct evdev *evdev;
1376         int minor;
1377         int dev_no;
1378         int error;
1379
1380         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1381         if (minor < 0) {
1382                 error = minor;
1383                 pr_err("failed to reserve new minor: %d\n", error);
1384                 return error;
1385         }
1386
1387         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1388         if (!evdev) {
1389                 error = -ENOMEM;
1390                 goto err_free_minor;
1391         }
1392
1393         INIT_LIST_HEAD(&evdev->client_list);
1394         spin_lock_init(&evdev->client_lock);
1395         mutex_init(&evdev->mutex);
1396         init_waitqueue_head(&evdev->wait);
1397         evdev->exist = true;
1398
1399         dev_no = minor;
1400         /* Normalize device number if it falls into legacy range */
1401         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1402                 dev_no -= EVDEV_MINOR_BASE;
1403         dev_set_name(&evdev->dev, "event%d", dev_no);
1404
1405         evdev->handle.dev = input_get_device(dev);
1406         evdev->handle.name = dev_name(&evdev->dev);
1407         evdev->handle.handler = handler;
1408         evdev->handle.private = evdev;
1409
1410         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1411         evdev->dev.class = &input_class;
1412         evdev->dev.parent = &dev->dev;
1413         evdev->dev.release = evdev_free;
1414         device_initialize(&evdev->dev);
1415
1416         error = input_register_handle(&evdev->handle);
1417         if (error)
1418                 goto err_free_evdev;
1419
1420         cdev_init(&evdev->cdev, &evdev_fops);
1421
1422         error = cdev_device_add(&evdev->cdev, &evdev->dev);
1423         if (error)
1424                 goto err_cleanup_evdev;
1425
1426         return 0;
1427
1428  err_cleanup_evdev:
1429         evdev_cleanup(evdev);
1430         input_unregister_handle(&evdev->handle);
1431  err_free_evdev:
1432         put_device(&evdev->dev);
1433  err_free_minor:
1434         input_free_minor(minor);
1435         return error;
1436 }
1437
1438 static void evdev_disconnect(struct input_handle *handle)
1439 {
1440         struct evdev *evdev = handle->private;
1441
1442         cdev_device_del(&evdev->cdev, &evdev->dev);
1443         evdev_cleanup(evdev);
1444         input_free_minor(MINOR(evdev->dev.devt));
1445         input_unregister_handle(handle);
1446         put_device(&evdev->dev);
1447 }
1448
1449 static const struct input_device_id evdev_ids[] = {
1450         { .driver_info = 1 },   /* Matches all devices */
1451         { },                    /* Terminating zero entry */
1452 };
1453
1454 MODULE_DEVICE_TABLE(input, evdev_ids);
1455
1456 static struct input_handler evdev_handler = {
1457         .event          = evdev_event,
1458         .events         = evdev_events,
1459         .connect        = evdev_connect,
1460         .disconnect     = evdev_disconnect,
1461         .legacy_minors  = true,
1462         .minor          = EVDEV_MINOR_BASE,
1463         .name           = "evdev",
1464         .id_table       = evdev_ids,
1465 };
1466
1467 static int __init evdev_init(void)
1468 {
1469         return input_register_handler(&evdev_handler);
1470 }
1471
1472 static void __exit evdev_exit(void)
1473 {
1474         input_unregister_handler(&evdev_handler);
1475 }
1476
1477 module_init(evdev_init);
1478 module_exit(evdev_exit);
1479
1480 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1481 MODULE_DESCRIPTION("Input driver event char devices");
1482 MODULE_LICENSE("GPL");