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                 kfree(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         nonseekable_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         }
 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         size_t len;
 929
 930         len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
 931         mem = kmalloc(len, GFP_KERNEL);
 932         if (!mem)
 933                 return -ENOMEM;
 934
 935         spin_lock_irq(&dev->event_lock);
 936         spin_lock(&client->buffer_lock);
 937
 938         memcpy(mem, bits, len);
 939
 940         spin_unlock(&dev->event_lock);
 941
 942         __evdev_flush_queue(client, type);
 943
 944         spin_unlock_irq(&client->buffer_lock);
 945
 946         ret = bits_to_user(mem, maxbit, maxlen, p, compat);
 947         if (ret < 0)
 948                 evdev_queue_syn_dropped(client);
 949
 950         kfree(mem);
 951
 952         return ret;
 953 }
 954
 955 static int evdev_handle_mt_request(struct input_dev *dev,
 956                                    unsigned int size,
 957                                    int __user *ip)
 958 {
 959         const struct input_mt *mt = dev->mt;
 960         unsigned int code;
 961         int max_slots;
 962         int i;
 963
 964         if (get_user(code, &ip[0]))
 965                 return -EFAULT;
 966         if (!mt || !input_is_mt_value(code))
 967                 return -EINVAL;
 968
 969         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 970         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 971                 int value = input_mt_get_value(&mt->slots[i], code);
 972                 if (put_user(value, &ip[1 + i]))
 973                         return -EFAULT;
 974         }
 975
 976         return 0;
 977 }
 978
 979 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
 980                         struct file *file)
 981 {
 982         client->revoked = true;
 983         evdev_ungrab(evdev, client);
 984         input_flush_device(&evdev->handle, file);
 985         wake_up_interruptible(&evdev->wait);
 986
 987         return 0;
 988 }
 989
 990 /* must be called with evdev-mutex held */
 991 static int evdev_set_mask(struct evdev_client *client,
 992                           unsigned int type,
 993                           const void __user *codes,
 994                           u32 codes_size,
 995                           int compat)
 996 {
 997         unsigned long flags, *mask, *oldmask;
 998         size_t cnt;
 999         int error;
1000
1001         /* we allow unknown types and 'codes_size > size' for forward-compat */
1002         cnt = evdev_get_mask_cnt(type);
1003         if (!cnt)
1004                 return 0;
1005
1006         mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL);
1007         if (!mask)
1008                 return -ENOMEM;
1009
1010         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1011         if (error < 0) {
1012                 kfree(mask);
1013                 return error;
1014         }
1015
1016         spin_lock_irqsave(&client->buffer_lock, flags);
1017         oldmask = client->evmasks[type];
1018         client->evmasks[type] = mask;
1019         spin_unlock_irqrestore(&client->buffer_lock, flags);
1020
1021         kfree(oldmask);
1022
1023         return 0;
1024 }
1025
1026 /* must be called with evdev-mutex held */
1027 static int evdev_get_mask(struct evdev_client *client,
1028                           unsigned int type,
1029                           void __user *codes,
1030                           u32 codes_size,
1031                           int compat)
1032 {
1033         unsigned long *mask;
1034         size_t cnt, size, xfer_size;
1035         int i;
1036         int error;
1037
1038         /* we allow unknown types and 'codes_size > size' for forward-compat */
1039         cnt = evdev_get_mask_cnt(type);
1040         size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1041         xfer_size = min_t(size_t, codes_size, size);
1042
1043         if (cnt > 0) {
1044                 mask = client->evmasks[type];
1045                 if (mask) {
1046                         error = bits_to_user(mask, cnt - 1,
1047                                              xfer_size, codes, compat);
1048                         if (error < 0)
1049                                 return error;
1050                 } else {
1051                         /* fake mask with all bits set */
1052                         for (i = 0; i < xfer_size; i++)
1053                                 if (put_user(0xffU, (u8 __user *)codes + i))
1054                                         return -EFAULT;
1055                 }
1056         }
1057
1058         if (xfer_size < codes_size)
1059                 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1060                         return -EFAULT;
1061
1062         return 0;
1063 }
1064
1065 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1066                            void __user *p, int compat_mode)
1067 {
1068         struct evdev_client *client = file->private_data;
1069         struct evdev *evdev = client->evdev;
1070         struct input_dev *dev = evdev->handle.dev;
1071         struct input_absinfo abs;
1072         struct input_mask mask;
1073         struct ff_effect effect;
1074         int __user *ip = (int __user *)p;
1075         unsigned int i, t, u, v;
1076         unsigned int size;
1077         int error;
1078
1079         /* First we check for fixed-length commands */
1080         switch (cmd) {
1081
1082         case EVIOCGVERSION:
1083                 return put_user(EV_VERSION, ip);
1084
1085         case EVIOCGID:
1086                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1087                         return -EFAULT;
1088                 return 0;
1089
1090         case EVIOCGREP:
1091                 if (!test_bit(EV_REP, dev->evbit))
1092                         return -ENOSYS;
1093                 if (put_user(dev->rep[REP_DELAY], ip))
1094                         return -EFAULT;
1095                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1096                         return -EFAULT;
1097                 return 0;
1098
1099         case EVIOCSREP:
1100                 if (!test_bit(EV_REP, dev->evbit))
1101                         return -ENOSYS;
1102                 if (get_user(u, ip))
1103                         return -EFAULT;
1104                 if (get_user(v, ip + 1))
1105                         return -EFAULT;
1106
1107                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1108                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1109
1110                 return 0;
1111
1112         case EVIOCRMFF:
1113                 return input_ff_erase(dev, (int)(unsigned long) p, file);
1114
1115         case EVIOCGEFFECTS:
1116                 i = test_bit(EV_FF, dev->evbit) ?
1117                                 dev->ff->max_effects : 0;
1118                 if (put_user(i, ip))
1119                         return -EFAULT;
1120                 return 0;
1121
1122         case EVIOCGRAB:
1123                 if (p)
1124                         return evdev_grab(evdev, client);
1125                 else
1126                         return evdev_ungrab(evdev, client);
1127
1128         case EVIOCREVOKE:
1129                 if (p)
1130                         return -EINVAL;
1131                 else
1132                         return evdev_revoke(evdev, client, file);
1133
1134         case EVIOCGMASK: {
1135                 void __user *codes_ptr;
1136
1137                 if (copy_from_user(&mask, p, sizeof(mask)))
1138                         return -EFAULT;
1139
1140                 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1141                 return evdev_get_mask(client,
1142                                       mask.type, codes_ptr, mask.codes_size,
1143                                       compat_mode);
1144         }
1145
1146         case EVIOCSMASK: {
1147                 const void __user *codes_ptr;
1148
1149                 if (copy_from_user(&mask, p, sizeof(mask)))
1150                         return -EFAULT;
1151
1152                 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1153                 return evdev_set_mask(client,
1154                                       mask.type, codes_ptr, mask.codes_size,
1155                                       compat_mode);
1156         }
1157
1158         case EVIOCSCLOCKID:
1159                 if (copy_from_user(&i, p, sizeof(unsigned int)))
1160                         return -EFAULT;
1161
1162                 return evdev_set_clk_type(client, i);
1163
1164         case EVIOCGKEYCODE:
1165                 return evdev_handle_get_keycode(dev, p);
1166
1167         case EVIOCSKEYCODE:
1168                 return evdev_handle_set_keycode(dev, p);
1169
1170         case EVIOCGKEYCODE_V2:
1171                 return evdev_handle_get_keycode_v2(dev, p);
1172
1173         case EVIOCSKEYCODE_V2:
1174                 return evdev_handle_set_keycode_v2(dev, p);
1175         }
1176
1177         size = _IOC_SIZE(cmd);
1178
1179         /* Now check variable-length commands */
1180 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1181         switch (EVIOC_MASK_SIZE(cmd)) {
1182
1183         case EVIOCGPROP(0):
1184                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1185                                     size, p, compat_mode);
1186
1187         case EVIOCGMTSLOTS(0):
1188                 return evdev_handle_mt_request(dev, size, ip);
1189
1190         case EVIOCGKEY(0):
1191                 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1192                                             KEY_MAX, size, p, compat_mode);
1193
1194         case EVIOCGLED(0):
1195                 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1196                                             LED_MAX, size, p, compat_mode);
1197
1198         case EVIOCGSND(0):
1199                 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1200                                             SND_MAX, size, p, compat_mode);
1201
1202         case EVIOCGSW(0):
1203                 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1204                                             SW_MAX, size, p, compat_mode);
1205
1206         case EVIOCGNAME(0):
1207                 return str_to_user(dev->name, size, p);
1208
1209         case EVIOCGPHYS(0):
1210                 return str_to_user(dev->phys, size, p);
1211
1212         case EVIOCGUNIQ(0):
1213                 return str_to_user(dev->uniq, size, p);
1214
1215         case EVIOC_MASK_SIZE(EVIOCSFF):
1216                 if (input_ff_effect_from_user(p, size, &effect))
1217                         return -EFAULT;
1218
1219                 error = input_ff_upload(dev, &effect, file);
1220                 if (error)
1221                         return error;
1222
1223                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1224                         return -EFAULT;
1225
1226                 return 0;
1227         }
1228
1229         /* Multi-number variable-length handlers */
1230         if (_IOC_TYPE(cmd) != 'E')
1231                 return -EINVAL;
1232
1233         if (_IOC_DIR(cmd) == _IOC_READ) {
1234
1235                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1236                         return handle_eviocgbit(dev,
1237                                                 _IOC_NR(cmd) & EV_MAX, size,
1238                                                 p, compat_mode);
1239
1240                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1241
1242                         if (!dev->absinfo)
1243                                 return -EINVAL;
1244
1245                         t = _IOC_NR(cmd) & ABS_MAX;
1246                         abs = dev->absinfo[t];
1247
1248                         if (copy_to_user(p, &abs, min_t(size_t,
1249                                         size, sizeof(struct input_absinfo))))
1250                                 return -EFAULT;
1251
1252                         return 0;
1253                 }
1254         }
1255
1256         if (_IOC_DIR(cmd) == _IOC_WRITE) {
1257
1258                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1259
1260                         if (!dev->absinfo)
1261                                 return -EINVAL;
1262
1263                         t = _IOC_NR(cmd) & ABS_MAX;
1264
1265                         if (copy_from_user(&abs, p, min_t(size_t,
1266                                         size, sizeof(struct input_absinfo))))
1267                                 return -EFAULT;
1268
1269                         if (size < sizeof(struct input_absinfo))
1270                                 abs.resolution = 0;
1271
1272                         /* We can't change number of reserved MT slots */
1273                         if (t == ABS_MT_SLOT)
1274                                 return -EINVAL;
1275
1276                         /*
1277                          * Take event lock to ensure that we are not
1278                          * changing device parameters in the middle
1279                          * of event.
1280                          */
1281                         spin_lock_irq(&dev->event_lock);
1282                         dev->absinfo[t] = abs;
1283                         spin_unlock_irq(&dev->event_lock);
1284
1285                         return 0;
1286                 }
1287         }
1288
1289         return -EINVAL;
1290 }
1291
1292 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1293                                 void __user *p, int compat_mode)
1294 {
1295         struct evdev_client *client = file->private_data;
1296         struct evdev *evdev = client->evdev;
1297         int retval;
1298
1299         retval = mutex_lock_interruptible(&evdev->mutex);
1300         if (retval)
1301                 return retval;
1302
1303         if (!evdev->exist || client->revoked) {
1304                 retval = -ENODEV;
1305                 goto out;
1306         }
1307
1308         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1309
1310  out:
1311         mutex_unlock(&evdev->mutex);
1312         return retval;
1313 }
1314
1315 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1316 {
1317         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1318 }
1319
1320 #ifdef CONFIG_COMPAT
1321 static long evdev_ioctl_compat(struct file *file,
1322                                 unsigned int cmd, unsigned long arg)
1323 {
1324         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1325 }
1326 #endif
1327
1328 static const struct file_operations evdev_fops = {
1329         .owner          = THIS_MODULE,
1330         .read           = evdev_read,
1331         .write          = evdev_write,
1332         .poll           = evdev_poll,
1333         .open           = evdev_open,
1334         .release        = evdev_release,
1335         .unlocked_ioctl = evdev_ioctl,
1336 #ifdef CONFIG_COMPAT
1337         .compat_ioctl   = evdev_ioctl_compat,
1338 #endif
1339         .fasync         = evdev_fasync,
1340         .flush          = evdev_flush,
1341         .llseek         = no_llseek,
1342 };
1343
1344 /*
1345  * Mark device non-existent. This disables writes, ioctls and
1346  * prevents new users from opening the device. Already posted
1347  * blocking reads will stay, however new ones will fail.
1348  */
1349 static void evdev_mark_dead(struct evdev *evdev)
1350 {
1351         mutex_lock(&evdev->mutex);
1352         evdev->exist = false;
1353         mutex_unlock(&evdev->mutex);
1354 }
1355
1356 static void evdev_cleanup(struct evdev *evdev)
1357 {
1358         struct input_handle *handle = &evdev->handle;
1359
1360         evdev_mark_dead(evdev);
1361         evdev_hangup(evdev);
1362
1363         /* evdev is marked dead so no one else accesses evdev->open */
1364         if (evdev->open) {
1365                 input_flush_device(handle, NULL);
1366                 input_close_device(handle);
1367         }
1368 }
1369
1370 /*
1371  * Create new evdev device. Note that input core serializes calls
1372  * to connect and disconnect.
1373  */
1374 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1375                          const struct input_device_id *id)
1376 {
1377         struct evdev *evdev;
1378         int minor;
1379         int dev_no;
1380         int error;
1381
1382         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1383         if (minor < 0) {
1384                 error = minor;
1385                 pr_err("failed to reserve new minor: %d\n", error);
1386                 return error;
1387         }
1388
1389         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1390         if (!evdev) {
1391                 error = -ENOMEM;
1392                 goto err_free_minor;
1393         }
1394
1395         INIT_LIST_HEAD(&evdev->client_list);
1396         spin_lock_init(&evdev->client_lock);
1397         mutex_init(&evdev->mutex);
1398         init_waitqueue_head(&evdev->wait);
1399         evdev->exist = true;
1400
1401         dev_no = minor;
1402         /* Normalize device number if it falls into legacy range */
1403         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1404                 dev_no -= EVDEV_MINOR_BASE;
1405         dev_set_name(&evdev->dev, "event%d", dev_no);
1406
1407         evdev->handle.dev = input_get_device(dev);
1408         evdev->handle.name = dev_name(&evdev->dev);
1409         evdev->handle.handler = handler;
1410         evdev->handle.private = evdev;
1411
1412         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1413         evdev->dev.class = &input_class;
1414         evdev->dev.parent = &dev->dev;
1415         evdev->dev.release = evdev_free;
1416         device_initialize(&evdev->dev);
1417
1418         error = input_register_handle(&evdev->handle);
1419         if (error)
1420                 goto err_free_evdev;
1421
1422         cdev_init(&evdev->cdev, &evdev_fops);
1423
1424         error = cdev_device_add(&evdev->cdev, &evdev->dev);
1425         if (error)
1426                 goto err_cleanup_evdev;
1427
1428         return 0;
1429
1430  err_cleanup_evdev:
1431         evdev_cleanup(evdev);
1432         input_unregister_handle(&evdev->handle);
1433  err_free_evdev:
1434         put_device(&evdev->dev);
1435  err_free_minor:
1436         input_free_minor(minor);
1437         return error;
1438 }
1439
1440 static void evdev_disconnect(struct input_handle *handle)
1441 {
1442         struct evdev *evdev = handle->private;
1443
1444         cdev_device_del(&evdev->cdev, &evdev->dev);
1445         evdev_cleanup(evdev);
1446         input_free_minor(MINOR(evdev->dev.devt));
1447         input_unregister_handle(handle);
1448         put_device(&evdev->dev);
1449 }
1450
1451 static const struct input_device_id evdev_ids[] = {
1452         { .driver_info = 1 },   /* Matches all devices */
1453         { },                    /* Terminating zero entry */
1454 };
1455
1456 MODULE_DEVICE_TABLE(input, evdev_ids);
1457
1458 static struct input_handler evdev_handler = {
1459         .event          = evdev_event,
1460         .events         = evdev_events,
1461         .connect        = evdev_connect,
1462         .disconnect     = evdev_disconnect,
1463         .legacy_minors  = true,
1464         .minor          = EVDEV_MINOR_BASE,
1465         .name           = "evdev",
1466         .id_table       = evdev_ids,
1467 };
1468
1469 static int __init evdev_init(void)
1470 {
1471         return input_register_handler(&evdev_handler);
1472 }
1473
1474 static void __exit evdev_exit(void)
1475 {
1476         input_unregister_handler(&evdev_handler);
1477 }
1478
1479 module_init(evdev_init);
1480 module_exit(evdev_exit);
1481
1482 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1483 MODULE_DESCRIPTION("Input driver event char devices");
1484 MODULE_LICENSE("GPL");