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         unsigned int size = sizeof(struct evdev_client) +
 507                                         bufsize * sizeof(struct input_event);
 508         struct evdev_client *client;
 509         int error;
 510
 511         client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
 512         if (!client)
 513                 client = vzalloc(size);
 514         if (!client)
 515                 return -ENOMEM;
 516
 517         client->bufsize = bufsize;
 518         spin_lock_init(&client->buffer_lock);
 519         client->evdev = evdev;
 520         evdev_attach_client(evdev, client);
 521
 522         error = evdev_open_device(evdev);
 523         if (error)
 524                 goto err_free_client;
 525
 526         file->private_data = client;
 527         stream_open(inode, file);
 528
 529         return 0;
 530
 531  err_free_client:
 532         evdev_detach_client(evdev, client);
 533         kvfree(client);
 534         return error;
 535 }
 536
 537 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 538                            size_t count, loff_t *ppos)
 539 {
 540         struct evdev_client *client = file->private_data;
 541         struct evdev *evdev = client->evdev;
 542         struct input_event event;
 543         int retval = 0;
 544
 545         if (count != 0 && count < input_event_size())
 546                 return -EINVAL;
 547
 548         retval = mutex_lock_interruptible(&evdev->mutex);
 549         if (retval)
 550                 return retval;
 551
 552         if (!evdev->exist || client->revoked) {
 553                 retval = -ENODEV;
 554                 goto out;
 555         }
 556
 557         while (retval + input_event_size() <= count) {
 558
 559                 if (input_event_from_user(buffer + retval, &event)) {
 560                         retval = -EFAULT;
 561                         goto out;
 562                 }
 563                 retval += input_event_size();
 564
 565                 input_inject_event(&evdev->handle,
 566                                    event.type, event.code, event.value);
 567                 cond_resched();
 568         }
 569
 570  out:
 571         mutex_unlock(&evdev->mutex);
 572         return retval;
 573 }
 574
 575 static int evdev_fetch_next_event(struct evdev_client *client,
 576                                   struct input_event *event)
 577 {
 578         int have_event;
 579
 580         spin_lock_irq(&client->buffer_lock);
 581
 582         have_event = client->packet_head != client->tail;
 583         if (have_event) {
 584                 *event = client->buffer[client->tail++];
 585                 client->tail &= client->bufsize - 1;
 586         }
 587
 588         spin_unlock_irq(&client->buffer_lock);
 589
 590         return have_event;
 591 }
 592
 593 static ssize_t evdev_read(struct file *file, char __user *buffer,
 594                           size_t count, loff_t *ppos)
 595 {
 596         struct evdev_client *client = file->private_data;
 597         struct evdev *evdev = client->evdev;
 598         struct input_event event;
 599         size_t read = 0;
 600         int error;
 601
 602         if (count != 0 && count < input_event_size())
 603                 return -EINVAL;
 604
 605         for (;;) {
 606                 if (!evdev->exist || client->revoked)
 607                         return -ENODEV;
 608
 609                 if (client->packet_head == client->tail &&
 610                     (file->f_flags & O_NONBLOCK))
 611                         return -EAGAIN;
 612
 613                 /*
 614                  * count == 0 is special - no IO is done but we check
 615                  * for error conditions (see above).
 616                  */
 617                 if (count == 0)
 618                         break;
 619
 620                 while (read + input_event_size() <= count &&
 621                        evdev_fetch_next_event(client, &event)) {
 622
 623                         if (input_event_to_user(buffer + read, &event))
 624                                 return -EFAULT;
 625
 626                         read += input_event_size();
 627                 }
 628
 629                 if (read)
 630                         break;
 631
 632                 if (!(file->f_flags & O_NONBLOCK)) {
 633                         error = wait_event_interruptible(evdev->wait,
 634                                         client->packet_head != client->tail ||
 635                                         !evdev->exist || client->revoked);
 636                         if (error)
 637                                 return error;
 638                 }
 639         }
 640
 641         return read;
 642 }
 643
 644 /* No kernel lock - fine */
 645 static __poll_t evdev_poll(struct file *file, poll_table *wait)
 646 {
 647         struct evdev_client *client = file->private_data;
 648         struct evdev *evdev = client->evdev;
 649         __poll_t mask;
 650
 651         poll_wait(file, &evdev->wait, wait);
 652
 653         if (evdev->exist && !client->revoked)
 654                 mask = EPOLLOUT | EPOLLWRNORM;
 655         else
 656                 mask = EPOLLHUP | EPOLLERR;
 657
 658         if (client->packet_head != client->tail)
 659                 mask |= EPOLLIN | EPOLLRDNORM;
 660
 661         return mask;
 662 }
 663
 664 #ifdef CONFIG_COMPAT
 665
 666 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 667 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 668
 669 #ifdef __BIG_ENDIAN
 670 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 671                         unsigned int maxlen, void __user *p, int compat)
 672 {
 673         int len, i;
 674
 675         if (compat) {
 676                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 677                 if (len > maxlen)
 678                         len = maxlen;
 679
 680                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 681                         if (copy_to_user((compat_long_t __user *) p + i,
 682                                          (compat_long_t *) bits +
 683                                                 i + 1 - ((i % 2) << 1),
 684                                          sizeof(compat_long_t)))
 685                                 return -EFAULT;
 686         } else {
 687                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 688                 if (len > maxlen)
 689                         len = maxlen;
 690
 691                 if (copy_to_user(p, bits, len))
 692                         return -EFAULT;
 693         }
 694
 695         return len;
 696 }
 697
 698 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 699                           unsigned int maxlen, const void __user *p, int compat)
 700 {
 701         int len, i;
 702
 703         if (compat) {
 704                 if (maxlen % sizeof(compat_long_t))
 705                         return -EINVAL;
 706
 707                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 708                 if (len > maxlen)
 709                         len = maxlen;
 710
 711                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 712                         if (copy_from_user((compat_long_t *) bits +
 713                                                 i + 1 - ((i % 2) << 1),
 714                                            (compat_long_t __user *) p + i,
 715                                            sizeof(compat_long_t)))
 716                                 return -EFAULT;
 717                 if (i % 2)
 718                         *((compat_long_t *) bits + i - 1) = 0;
 719
 720         } else {
 721                 if (maxlen % sizeof(long))
 722                         return -EINVAL;
 723
 724                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 725                 if (len > maxlen)
 726                         len = maxlen;
 727
 728                 if (copy_from_user(bits, p, len))
 729                         return -EFAULT;
 730         }
 731
 732         return len;
 733 }
 734
 735 #else
 736
 737 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 738                         unsigned int maxlen, void __user *p, int compat)
 739 {
 740         int len = compat ?
 741                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 742                         BITS_TO_LONGS(maxbit) * sizeof(long);
 743
 744         if (len > maxlen)
 745                 len = maxlen;
 746
 747         return copy_to_user(p, bits, len) ? -EFAULT : len;
 748 }
 749
 750 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 751                           unsigned int maxlen, const void __user *p, int compat)
 752 {
 753         size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
 754         int len;
 755
 756         if (maxlen % chunk_size)
 757                 return -EINVAL;
 758
 759         len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
 760         len *= chunk_size;
 761         if (len > maxlen)
 762                 len = maxlen;
 763
 764         return copy_from_user(bits, p, len) ? -EFAULT : len;
 765 }
 766
 767 #endif /* __BIG_ENDIAN */
 768
 769 #else
 770
 771 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 772                         unsigned int maxlen, void __user *p, int compat)
 773 {
 774         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 775
 776         if (len > maxlen)
 777                 len = maxlen;
 778
 779         return copy_to_user(p, bits, len) ? -EFAULT : len;
 780 }
 781
 782 static int bits_from_user(unsigned long *bits, unsigned int maxbit,
 783                           unsigned int maxlen, const void __user *p, int compat)
 784 {
 785         int len;
 786
 787         if (maxlen % sizeof(long))
 788                 return -EINVAL;
 789
 790         len = BITS_TO_LONGS(maxbit) * sizeof(long);
 791         if (len > maxlen)
 792                 len = maxlen;
 793
 794         return copy_from_user(bits, p, len) ? -EFAULT : len;
 795 }
 796
 797 #endif /* CONFIG_COMPAT */
 798
 799 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 800 {
 801         int len;
 802
 803         if (!str)
 804                 return -ENOENT;
 805
 806         len = strlen(str) + 1;
 807         if (len > maxlen)
 808                 len = maxlen;
 809
 810         return copy_to_user(p, str, len) ? -EFAULT : len;
 811 }
 812
 813 static int handle_eviocgbit(struct input_dev *dev,
 814                             unsigned int type, unsigned int size,
 815                             void __user *p, int compat_mode)
 816 {
 817         unsigned long *bits;
 818         int len;
 819
 820         switch (type) {
 821
 822         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 823         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 824         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 825         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 826         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 827         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 828         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 829         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 830         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 831         default: return -EINVAL;
 832         }
 833
 834         return bits_to_user(bits, len, size, p, compat_mode);
 835 }
 836
 837 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 838 {
 839         struct input_keymap_entry ke = {
 840                 .len    = sizeof(unsigned int),
 841                 .flags  = 0,
 842         };
 843         int __user *ip = (int __user *)p;
 844         int error;
 845
 846         /* legacy case */
 847         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 848                 return -EFAULT;
 849
 850         error = input_get_keycode(dev, &ke);
 851         if (error)
 852                 return error;
 853
 854         if (put_user(ke.keycode, ip + 1))
 855                 return -EFAULT;
 856
 857         return 0;
 858 }
 859
 860 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 861 {
 862         struct input_keymap_entry ke;
 863         int error;
 864
 865         if (copy_from_user(&ke, p, sizeof(ke)))
 866                 return -EFAULT;
 867
 868         error = input_get_keycode(dev, &ke);
 869         if (error)
 870                 return error;
 871
 872         if (copy_to_user(p, &ke, sizeof(ke)))
 873                 return -EFAULT;
 874
 875         return 0;
 876 }
 877
 878 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 879 {
 880         struct input_keymap_entry ke = {
 881                 .len    = sizeof(unsigned int),
 882                 .flags  = 0,
 883         };
 884         int __user *ip = (int __user *)p;
 885
 886         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 887                 return -EFAULT;
 888
 889         if (get_user(ke.keycode, ip + 1))
 890                 return -EFAULT;
 891
 892         return input_set_keycode(dev, &ke);
 893 }
 894
 895 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 896 {
 897         struct input_keymap_entry ke;
 898
 899         if (copy_from_user(&ke, p, sizeof(ke)))
 900                 return -EFAULT;
 901
 902         if (ke.len > sizeof(ke.scancode))
 903                 return -EINVAL;
 904
 905         return input_set_keycode(dev, &ke);
 906 }
 907
 908 /*
 909  * If we transfer state to the user, we should flush all pending events
 910  * of the same type from the client's queue. Otherwise, they might end up
 911  * with duplicate events, which can screw up client's state tracking.
 912  * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
 913  * event so user-space will notice missing events.
 914  *
 915  * LOCKING:
 916  * We need to take event_lock before buffer_lock to avoid dead-locks. But we
 917  * need the even_lock only to guarantee consistent state. We can safely release
 918  * it while flushing the queue. This allows input-core to handle filters while
 919  * we flush the queue.
 920  */
 921 static int evdev_handle_get_val(struct evdev_client *client,
 922                                 struct input_dev *dev, unsigned int type,
 923                                 unsigned long *bits, unsigned int maxbit,
 924                                 unsigned int maxlen, void __user *p,
 925                                 int compat)
 926 {
 927         int ret;
 928         unsigned long *mem;
 929
 930         mem = bitmap_alloc(maxbit, GFP_KERNEL);
 931         if (!mem)
 932                 return -ENOMEM;
 933
 934         spin_lock_irq(&dev->event_lock);
 935         spin_lock(&client->buffer_lock);
 936
 937         bitmap_copy(mem, bits, maxbit);
 938
 939         spin_unlock(&dev->event_lock);
 940
 941         __evdev_flush_queue(client, type);
 942
 943         spin_unlock_irq(&client->buffer_lock);
 944
 945         ret = bits_to_user(mem, maxbit, maxlen, p, compat);
 946         if (ret < 0)
 947                 evdev_queue_syn_dropped(client);
 948
 949         bitmap_free(mem);
 950
 951         return ret;
 952 }
 953
 954 static int evdev_handle_mt_request(struct input_dev *dev,
 955                                    unsigned int size,
 956                                    int __user *ip)
 957 {
 958         const struct input_mt *mt = dev->mt;
 959         unsigned int code;
 960         int max_slots;
 961         int i;
 962
 963         if (get_user(code, &ip[0]))
 964                 return -EFAULT;
 965         if (!mt || !input_is_mt_value(code))
 966                 return -EINVAL;
 967
 968         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 969         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 970                 int value = input_mt_get_value(&mt->slots[i], code);
 971                 if (put_user(value, &ip[1 + i]))
 972                         return -EFAULT;
 973         }
 974
 975         return 0;
 976 }
 977
 978 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
 979                         struct file *file)
 980 {
 981         client->revoked = true;
 982         evdev_ungrab(evdev, client);
 983         input_flush_device(&evdev->handle, file);
 984         wake_up_interruptible(&evdev->wait);
 985
 986         return 0;
 987 }
 988
 989 /* must be called with evdev-mutex held */
 990 static int evdev_set_mask(struct evdev_client *client,
 991                           unsigned int type,
 992                           const void __user *codes,
 993                           u32 codes_size,
 994                           int compat)
 995 {
 996         unsigned long flags, *mask, *oldmask;
 997         size_t cnt;
 998         int error;
 999
1000         /* we allow unknown types and 'codes_size > size' for forward-compat */
1001         cnt = evdev_get_mask_cnt(type);
1002         if (!cnt)
1003                 return 0;
1004
1005         mask = bitmap_zalloc(cnt, GFP_KERNEL);
1006         if (!mask)
1007                 return -ENOMEM;
1008
1009         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1010         if (error < 0) {
1011                 bitmap_free(mask);
1012                 return error;
1013         }
1014
1015         spin_lock_irqsave(&client->buffer_lock, flags);
1016         oldmask = client->evmasks[type];
1017         client->evmasks[type] = mask;
1018         spin_unlock_irqrestore(&client->buffer_lock, flags);
1019
1020         bitmap_free(oldmask);
1021
1022         return 0;
1023 }
1024
1025 /* must be called with evdev-mutex held */
1026 static int evdev_get_mask(struct evdev_client *client,
1027                           unsigned int type,
1028                           void __user *codes,
1029                           u32 codes_size,
1030                           int compat)
1031 {
1032         unsigned long *mask;
1033         size_t cnt, size, xfer_size;
1034         int i;
1035         int error;
1036
1037         /* we allow unknown types and 'codes_size > size' for forward-compat */
1038         cnt = evdev_get_mask_cnt(type);
1039         size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1040         xfer_size = min_t(size_t, codes_size, size);
1041
1042         if (cnt > 0) {
1043                 mask = client->evmasks[type];
1044                 if (mask) {
1045                         error = bits_to_user(mask, cnt - 1,
1046                                              xfer_size, codes, compat);
1047                         if (error < 0)
1048                                 return error;
1049                 } else {
1050                         /* fake mask with all bits set */
1051                         for (i = 0; i < xfer_size; i++)
1052                                 if (put_user(0xffU, (u8 __user *)codes + i))
1053                                         return -EFAULT;
1054                 }
1055         }
1056
1057         if (xfer_size < codes_size)
1058                 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1059                         return -EFAULT;
1060
1061         return 0;
1062 }
1063
1064 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1065                            void __user *p, int compat_mode)
1066 {
1067         struct evdev_client *client = file->private_data;
1068         struct evdev *evdev = client->evdev;
1069         struct input_dev *dev = evdev->handle.dev;
1070         struct input_absinfo abs;
1071         struct input_mask mask;
1072         struct ff_effect effect;
1073         int __user *ip = (int __user *)p;
1074         unsigned int i, t, u, v;
1075         unsigned int size;
1076         int error;
1077
1078         /* First we check for fixed-length commands */
1079         switch (cmd) {
1080
1081         case EVIOCGVERSION:
1082                 return put_user(EV_VERSION, ip);
1083
1084         case EVIOCGID:
1085                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1086                         return -EFAULT;
1087                 return 0;
1088
1089         case EVIOCGREP:
1090                 if (!test_bit(EV_REP, dev->evbit))
1091                         return -ENOSYS;
1092                 if (put_user(dev->rep[REP_DELAY], ip))
1093                         return -EFAULT;
1094                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1095                         return -EFAULT;
1096                 return 0;
1097
1098         case EVIOCSREP:
1099                 if (!test_bit(EV_REP, dev->evbit))
1100                         return -ENOSYS;
1101                 if (get_user(u, ip))
1102                         return -EFAULT;
1103                 if (get_user(v, ip + 1))
1104                         return -EFAULT;
1105
1106                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1107                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1108
1109                 return 0;
1110
1111         case EVIOCRMFF:
1112                 return input_ff_erase(dev, (int)(unsigned long) p, file);
1113
1114         case EVIOCGEFFECTS:
1115                 i = test_bit(EV_FF, dev->evbit) ?
1116                                 dev->ff->max_effects : 0;
1117                 if (put_user(i, ip))
1118                         return -EFAULT;
1119                 return 0;
1120
1121         case EVIOCGRAB:
1122                 if (p)
1123                         return evdev_grab(evdev, client);
1124                 else
1125                         return evdev_ungrab(evdev, client);
1126
1127         case EVIOCREVOKE:
1128                 if (p)
1129                         return -EINVAL;
1130                 else
1131                         return evdev_revoke(evdev, client, file);
1132
1133         case EVIOCGMASK: {
1134                 void __user *codes_ptr;
1135
1136                 if (copy_from_user(&mask, p, sizeof(mask)))
1137                         return -EFAULT;
1138
1139                 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1140                 return evdev_get_mask(client,
1141                                       mask.type, codes_ptr, mask.codes_size,
1142                                       compat_mode);
1143         }
1144
1145         case EVIOCSMASK: {
1146                 const void __user *codes_ptr;
1147
1148                 if (copy_from_user(&mask, p, sizeof(mask)))
1149                         return -EFAULT;
1150
1151                 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1152                 return evdev_set_mask(client,
1153                                       mask.type, codes_ptr, mask.codes_size,
1154                                       compat_mode);
1155         }
1156
1157         case EVIOCSCLOCKID:
1158                 if (copy_from_user(&i, p, sizeof(unsigned int)))
1159                         return -EFAULT;
1160
1161                 return evdev_set_clk_type(client, i);
1162
1163         case EVIOCGKEYCODE:
1164                 return evdev_handle_get_keycode(dev, p);
1165
1166         case EVIOCSKEYCODE:
1167                 return evdev_handle_set_keycode(dev, p);
1168
1169         case EVIOCGKEYCODE_V2:
1170                 return evdev_handle_get_keycode_v2(dev, p);
1171
1172         case EVIOCSKEYCODE_V2:
1173                 return evdev_handle_set_keycode_v2(dev, p);
1174         }
1175
1176         size = _IOC_SIZE(cmd);
1177
1178         /* Now check variable-length commands */
1179 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1180         switch (EVIOC_MASK_SIZE(cmd)) {
1181
1182         case EVIOCGPROP(0):
1183                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1184                                     size, p, compat_mode);
1185
1186         case EVIOCGMTSLOTS(0):
1187                 return evdev_handle_mt_request(dev, size, ip);
1188
1189         case EVIOCGKEY(0):
1190                 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1191                                             KEY_MAX, size, p, compat_mode);
1192
1193         case EVIOCGLED(0):
1194                 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1195                                             LED_MAX, size, p, compat_mode);
1196
1197         case EVIOCGSND(0):
1198                 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1199                                             SND_MAX, size, p, compat_mode);
1200
1201         case EVIOCGSW(0):
1202                 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1203                                             SW_MAX, size, p, compat_mode);
1204
1205         case EVIOCGNAME(0):
1206                 return str_to_user(dev->name, size, p);
1207
1208         case EVIOCGPHYS(0):
1209                 return str_to_user(dev->phys, size, p);
1210
1211         case EVIOCGUNIQ(0):
1212                 return str_to_user(dev->uniq, size, p);
1213
1214         case EVIOC_MASK_SIZE(EVIOCSFF):
1215                 if (input_ff_effect_from_user(p, size, &effect))
1216                         return -EFAULT;
1217
1218                 error = input_ff_upload(dev, &effect, file);
1219                 if (error)
1220                         return error;
1221
1222                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1223                         return -EFAULT;
1224
1225                 return 0;
1226         }
1227
1228         /* Multi-number variable-length handlers */
1229         if (_IOC_TYPE(cmd) != 'E')
1230                 return -EINVAL;
1231
1232         if (_IOC_DIR(cmd) == _IOC_READ) {
1233
1234                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1235                         return handle_eviocgbit(dev,
1236                                                 _IOC_NR(cmd) & EV_MAX, size,
1237                                                 p, compat_mode);
1238
1239                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1240
1241                         if (!dev->absinfo)
1242                                 return -EINVAL;
1243
1244                         t = _IOC_NR(cmd) & ABS_MAX;
1245                         abs = dev->absinfo[t];
1246
1247                         if (copy_to_user(p, &abs, min_t(size_t,
1248                                         size, sizeof(struct input_absinfo))))
1249                                 return -EFAULT;
1250
1251                         return 0;
1252                 }
1253         }
1254
1255         if (_IOC_DIR(cmd) == _IOC_WRITE) {
1256
1257                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1258
1259                         if (!dev->absinfo)
1260                                 return -EINVAL;
1261
1262                         t = _IOC_NR(cmd) & ABS_MAX;
1263
1264                         if (copy_from_user(&abs, p, min_t(size_t,
1265                                         size, sizeof(struct input_absinfo))))
1266                                 return -EFAULT;
1267
1268                         if (size < sizeof(struct input_absinfo))
1269                                 abs.resolution = 0;
1270
1271                         /* We can't change number of reserved MT slots */
1272                         if (t == ABS_MT_SLOT)
1273                                 return -EINVAL;
1274
1275                         /*
1276                          * Take event lock to ensure that we are not
1277                          * changing device parameters in the middle
1278                          * of event.
1279                          */
1280                         spin_lock_irq(&dev->event_lock);
1281                         dev->absinfo[t] = abs;
1282                         spin_unlock_irq(&dev->event_lock);
1283
1284                         return 0;
1285                 }
1286         }
1287
1288         return -EINVAL;
1289 }
1290
1291 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1292                                 void __user *p, int compat_mode)
1293 {
1294         struct evdev_client *client = file->private_data;
1295         struct evdev *evdev = client->evdev;
1296         int retval;
1297
1298         retval = mutex_lock_interruptible(&evdev->mutex);
1299         if (retval)
1300                 return retval;
1301
1302         if (!evdev->exist || client->revoked) {
1303                 retval = -ENODEV;
1304                 goto out;
1305         }
1306
1307         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1308
1309  out:
1310         mutex_unlock(&evdev->mutex);
1311         return retval;
1312 }
1313
1314 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1315 {
1316         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1317 }
1318
1319 #ifdef CONFIG_COMPAT
1320 static long evdev_ioctl_compat(struct file *file,
1321                                 unsigned int cmd, unsigned long arg)
1322 {
1323         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1324 }
1325 #endif
1326
1327 static const struct file_operations evdev_fops = {
1328         .owner          = THIS_MODULE,
1329         .read           = evdev_read,
1330         .write          = evdev_write,
1331         .poll           = evdev_poll,
1332         .open           = evdev_open,
1333         .release        = evdev_release,
1334         .unlocked_ioctl = evdev_ioctl,
1335 #ifdef CONFIG_COMPAT
1336         .compat_ioctl   = evdev_ioctl_compat,
1337 #endif
1338         .fasync         = evdev_fasync,
1339         .flush          = evdev_flush,
1340         .llseek         = no_llseek,
1341 };
1342
1343 /*
1344  * Mark device non-existent. This disables writes, ioctls and
1345  * prevents new users from opening the device. Already posted
1346  * blocking reads will stay, however new ones will fail.
1347  */
1348 static void evdev_mark_dead(struct evdev *evdev)
1349 {
1350         mutex_lock(&evdev->mutex);
1351         evdev->exist = false;
1352         mutex_unlock(&evdev->mutex);
1353 }
1354
1355 static void evdev_cleanup(struct evdev *evdev)
1356 {
1357         struct input_handle *handle = &evdev->handle;
1358
1359         evdev_mark_dead(evdev);
1360         evdev_hangup(evdev);
1361
1362         /* evdev is marked dead so no one else accesses evdev->open */
1363         if (evdev->open) {
1364                 input_flush_device(handle, NULL);
1365                 input_close_device(handle);
1366         }
1367 }
1368
1369 /*
1370  * Create new evdev device. Note that input core serializes calls
1371  * to connect and disconnect.
1372  */
1373 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1374                          const struct input_device_id *id)
1375 {
1376         struct evdev *evdev;
1377         int minor;
1378         int dev_no;
1379         int error;
1380
1381         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1382         if (minor < 0) {
1383                 error = minor;
1384                 pr_err("failed to reserve new minor: %d\n", error);
1385                 return error;
1386         }
1387
1388         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1389         if (!evdev) {
1390                 error = -ENOMEM;
1391                 goto err_free_minor;
1392         }
1393
1394         INIT_LIST_HEAD(&evdev->client_list);
1395         spin_lock_init(&evdev->client_lock);
1396         mutex_init(&evdev->mutex);
1397         init_waitqueue_head(&evdev->wait);
1398         evdev->exist = true;
1399
1400         dev_no = minor;
1401         /* Normalize device number if it falls into legacy range */
1402         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1403                 dev_no -= EVDEV_MINOR_BASE;
1404         dev_set_name(&evdev->dev, "event%d", dev_no);
1405
1406         evdev->handle.dev = input_get_device(dev);
1407         evdev->handle.name = dev_name(&evdev->dev);
1408         evdev->handle.handler = handler;
1409         evdev->handle.private = evdev;
1410
1411         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1412         evdev->dev.class = &input_class;
1413         evdev->dev.parent = &dev->dev;
1414         evdev->dev.release = evdev_free;
1415         device_initialize(&evdev->dev);
1416
1417         error = input_register_handle(&evdev->handle);
1418         if (error)
1419                 goto err_free_evdev;
1420
1421         cdev_init(&evdev->cdev, &evdev_fops);
1422
1423         error = cdev_device_add(&evdev->cdev, &evdev->dev);
1424         if (error)
1425                 goto err_cleanup_evdev;
1426
1427         return 0;
1428
1429  err_cleanup_evdev:
1430         evdev_cleanup(evdev);
1431         input_unregister_handle(&evdev->handle);
1432  err_free_evdev:
1433         put_device(&evdev->dev);
1434  err_free_minor:
1435         input_free_minor(minor);
1436         return error;
1437 }
1438
1439 static void evdev_disconnect(struct input_handle *handle)
1440 {
1441         struct evdev *evdev = handle->private;
1442
1443         cdev_device_del(&evdev->cdev, &evdev->dev);
1444         evdev_cleanup(evdev);
1445         input_free_minor(MINOR(evdev->dev.devt));
1446         input_unregister_handle(handle);
1447         put_device(&evdev->dev);
1448 }
1449
1450 static const struct input_device_id evdev_ids[] = {
1451         { .driver_info = 1 },   /* Matches all devices */
1452         { },                    /* Terminating zero entry */
1453 };
1454
1455 MODULE_DEVICE_TABLE(input, evdev_ids);
1456
1457 static struct input_handler evdev_handler = {
1458         .event          = evdev_event,
1459         .events         = evdev_events,
1460         .connect        = evdev_connect,
1461         .disconnect     = evdev_disconnect,
1462         .legacy_minors  = true,
1463         .minor          = EVDEV_MINOR_BASE,
1464         .name           = "evdev",
1465         .id_table       = evdev_ids,
1466 };
1467
1468 static int __init evdev_init(void)
1469 {
1470         return input_register_handler(&evdev_handler);
1471 }
1472
1473 static void __exit evdev_exit(void)
1474 {
1475         input_unregister_handler(&evdev_handler);
1476 }
1477
1478 module_init(evdev_init);
1479 module_exit(evdev_exit);
1480
1481 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1482 MODULE_DESCRIPTION("Input driver event char devices");
1483 MODULE_LICENSE("GPL");