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/module.h>
  22 #include <linux/init.h>
  23 #include <linux/input/mt.h>
  24 #include <linux/major.h>
  25 #include <linux/device.h>
  26 #include "input-compat.h"
  27
  28 struct evdev {
  29         int open;
  30         int minor;
  31         struct input_handle handle;
  32         wait_queue_head_t wait;
  33         struct evdev_client __rcu *grab;
  34         struct list_head client_list;
  35         spinlock_t client_lock; /* protects client_list */
  36         struct mutex mutex;
  37         struct device dev;
  38         bool exist;
  39 };
  40
  41 struct evdev_client {
  42         unsigned int head;
  43         unsigned int tail;
  44         unsigned int packet_head; /* [future] position of the first element of next packet */
  45         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  46         struct fasync_struct *fasync;
  47         struct evdev *evdev;
  48         struct list_head node;
  49         int clkid;
  50         unsigned int bufsize;
  51         struct input_event buffer[];
  52 };
  53
  54 static struct evdev *evdev_table[EVDEV_MINORS];
  55 static DEFINE_MUTEX(evdev_table_mutex);
  56
  57 static void evdev_pass_event(struct evdev_client *client,
  58                              struct input_event *event,
  59                              ktime_t mono, ktime_t real)
  60 {
  61         event->time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
  62                                         mono : real);
  63
  64         /* Interrupts are disabled, just acquire the lock. */
  65         spin_lock(&client->buffer_lock);
  66
  67         client->buffer[client->head++] = *event;
  68         client->head &= client->bufsize - 1;
  69
  70         if (unlikely(client->head == client->tail)) {
  71                 /*
  72                  * This effectively "drops" all unconsumed events, leaving
  73                  * EV_SYN/SYN_DROPPED plus the newest event in the queue.
  74                  */
  75                 client->tail = (client->head - 2) & (client->bufsize - 1);
  76
  77                 client->buffer[client->tail].time = event->time;
  78                 client->buffer[client->tail].type = EV_SYN;
  79                 client->buffer[client->tail].code = SYN_DROPPED;
  80                 client->buffer[client->tail].value = 0;
  81
  82                 client->packet_head = client->tail;
  83         }
  84
  85         if (event->type == EV_SYN && event->code == SYN_REPORT) {
  86                 client->packet_head = client->head;
  87                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
  88         }
  89
  90         spin_unlock(&client->buffer_lock);
  91 }
  92
  93 /*
  94  * Pass incoming event to all connected clients.
  95  */
  96 static void evdev_event(struct input_handle *handle,
  97                         unsigned int type, unsigned int code, int value)
  98 {
  99         struct evdev *evdev = handle->private;
 100         struct evdev_client *client;
 101         struct input_event event;
 102         ktime_t time_mono, time_real;
 103
 104         time_mono = ktime_get();
 105         time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
 106
 107         event.type = type;
 108         event.code = code;
 109         event.value = value;
 110
 111         rcu_read_lock();
 112
 113         client = rcu_dereference(evdev->grab);
 114
 115         if (client)
 116                 evdev_pass_event(client, &event, time_mono, time_real);
 117         else
 118                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 119                         evdev_pass_event(client, &event, time_mono, time_real);
 120
 121         rcu_read_unlock();
 122
 123         if (type == EV_SYN && code == SYN_REPORT)
 124                 wake_up_interruptible(&evdev->wait);
 125 }
 126
 127 static int evdev_fasync(int fd, struct file *file, int on)
 128 {
 129         struct evdev_client *client = file->private_data;
 130
 131         return fasync_helper(fd, file, on, &client->fasync);
 132 }
 133
 134 static int evdev_flush(struct file *file, fl_owner_t id)
 135 {
 136         struct evdev_client *client = file->private_data;
 137         struct evdev *evdev = client->evdev;
 138         int retval;
 139
 140         retval = mutex_lock_interruptible(&evdev->mutex);
 141         if (retval)
 142                 return retval;
 143
 144         if (!evdev->exist)
 145                 retval = -ENODEV;
 146         else
 147                 retval = input_flush_device(&evdev->handle, file);
 148
 149         mutex_unlock(&evdev->mutex);
 150         return retval;
 151 }
 152
 153 static void evdev_free(struct device *dev)
 154 {
 155         struct evdev *evdev = container_of(dev, struct evdev, dev);
 156
 157         input_put_device(evdev->handle.dev);
 158         kfree(evdev);
 159 }
 160
 161 /*
 162  * Grabs an event device (along with underlying input device).
 163  * This function is called with evdev->mutex taken.
 164  */
 165 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 166 {
 167         int error;
 168
 169         if (evdev->grab)
 170                 return -EBUSY;
 171
 172         error = input_grab_device(&evdev->handle);
 173         if (error)
 174                 return error;
 175
 176         rcu_assign_pointer(evdev->grab, client);
 177
 178         return 0;
 179 }
 180
 181 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 182 {
 183         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 184                                         lockdep_is_held(&evdev->mutex));
 185
 186         if (grab != client)
 187                 return  -EINVAL;
 188
 189         rcu_assign_pointer(evdev->grab, NULL);
 190         synchronize_rcu();
 191         input_release_device(&evdev->handle);
 192
 193         return 0;
 194 }
 195
 196 static void evdev_attach_client(struct evdev *evdev,
 197                                 struct evdev_client *client)
 198 {
 199         spin_lock(&evdev->client_lock);
 200         list_add_tail_rcu(&client->node, &evdev->client_list);
 201         spin_unlock(&evdev->client_lock);
 202 }
 203
 204 static void evdev_detach_client(struct evdev *evdev,
 205                                 struct evdev_client *client)
 206 {
 207         spin_lock(&evdev->client_lock);
 208         list_del_rcu(&client->node);
 209         spin_unlock(&evdev->client_lock);
 210         synchronize_rcu();
 211 }
 212
 213 static int evdev_open_device(struct evdev *evdev)
 214 {
 215         int retval;
 216
 217         retval = mutex_lock_interruptible(&evdev->mutex);
 218         if (retval)
 219                 return retval;
 220
 221         if (!evdev->exist)
 222                 retval = -ENODEV;
 223         else if (!evdev->open++) {
 224                 retval = input_open_device(&evdev->handle);
 225                 if (retval)
 226                         evdev->open--;
 227         }
 228
 229         mutex_unlock(&evdev->mutex);
 230         return retval;
 231 }
 232
 233 static void evdev_close_device(struct evdev *evdev)
 234 {
 235         mutex_lock(&evdev->mutex);
 236
 237         if (evdev->exist && !--evdev->open)
 238                 input_close_device(&evdev->handle);
 239
 240         mutex_unlock(&evdev->mutex);
 241 }
 242
 243 /*
 244  * Wake up users waiting for IO so they can disconnect from
 245  * dead device.
 246  */
 247 static void evdev_hangup(struct evdev *evdev)
 248 {
 249         struct evdev_client *client;
 250
 251         spin_lock(&evdev->client_lock);
 252         list_for_each_entry(client, &evdev->client_list, node)
 253                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 254         spin_unlock(&evdev->client_lock);
 255
 256         wake_up_interruptible(&evdev->wait);
 257 }
 258
 259 static int evdev_release(struct inode *inode, struct file *file)
 260 {
 261         struct evdev_client *client = file->private_data;
 262         struct evdev *evdev = client->evdev;
 263
 264         mutex_lock(&evdev->mutex);
 265         evdev_ungrab(evdev, client);
 266         mutex_unlock(&evdev->mutex);
 267
 268         evdev_detach_client(evdev, client);
 269         kfree(client);
 270
 271         evdev_close_device(evdev);
 272         put_device(&evdev->dev);
 273
 274         return 0;
 275 }
 276
 277 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 278 {
 279         unsigned int n_events =
 280                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 281                     EVDEV_MIN_BUFFER_SIZE);
 282
 283         return roundup_pow_of_two(n_events);
 284 }
 285
 286 static int evdev_open(struct inode *inode, struct file *file)
 287 {
 288         struct evdev *evdev;
 289         struct evdev_client *client;
 290         int i = iminor(inode) - EVDEV_MINOR_BASE;
 291         unsigned int bufsize;
 292         int error;
 293
 294         if (i >= EVDEV_MINORS)
 295                 return -ENODEV;
 296
 297         error = mutex_lock_interruptible(&evdev_table_mutex);
 298         if (error)
 299                 return error;
 300         evdev = evdev_table[i];
 301         if (evdev)
 302                 get_device(&evdev->dev);
 303         mutex_unlock(&evdev_table_mutex);
 304
 305         if (!evdev)
 306                 return -ENODEV;
 307
 308         bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 309
 310         client = kzalloc(sizeof(struct evdev_client) +
 311                                 bufsize * sizeof(struct input_event),
 312                          GFP_KERNEL);
 313         if (!client) {
 314                 error = -ENOMEM;
 315                 goto err_put_evdev;
 316         }
 317
 318         client->bufsize = bufsize;
 319         spin_lock_init(&client->buffer_lock);
 320         client->evdev = evdev;
 321         evdev_attach_client(evdev, client);
 322
 323         error = evdev_open_device(evdev);
 324         if (error)
 325                 goto err_free_client;
 326
 327         file->private_data = client;
 328         nonseekable_open(inode, file);
 329
 330         return 0;
 331
 332  err_free_client:
 333         evdev_detach_client(evdev, client);
 334         kfree(client);
 335  err_put_evdev:
 336         put_device(&evdev->dev);
 337         return error;
 338 }
 339
 340 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 341                            size_t count, loff_t *ppos)
 342 {
 343         struct evdev_client *client = file->private_data;
 344         struct evdev *evdev = client->evdev;
 345         struct input_event event;
 346         int retval = 0;
 347
 348         if (count != 0 && count < input_event_size())
 349                 return -EINVAL;
 350
 351         retval = mutex_lock_interruptible(&evdev->mutex);
 352         if (retval)
 353                 return retval;
 354
 355         if (!evdev->exist) {
 356                 retval = -ENODEV;
 357                 goto out;
 358         }
 359
 360         while (retval + input_event_size() <= count) {
 361
 362                 if (input_event_from_user(buffer + retval, &event)) {
 363                         retval = -EFAULT;
 364                         goto out;
 365                 }
 366                 retval += input_event_size();
 367
 368                 input_inject_event(&evdev->handle,
 369                                    event.type, event.code, event.value);
 370         }
 371
 372  out:
 373         mutex_unlock(&evdev->mutex);
 374         return retval;
 375 }
 376
 377 static int evdev_fetch_next_event(struct evdev_client *client,
 378                                   struct input_event *event)
 379 {
 380         int have_event;
 381
 382         spin_lock_irq(&client->buffer_lock);
 383
 384         have_event = client->packet_head != client->tail;
 385         if (have_event) {
 386                 *event = client->buffer[client->tail++];
 387                 client->tail &= client->bufsize - 1;
 388         }
 389
 390         spin_unlock_irq(&client->buffer_lock);
 391
 392         return have_event;
 393 }
 394
 395 static ssize_t evdev_read(struct file *file, char __user *buffer,
 396                           size_t count, loff_t *ppos)
 397 {
 398         struct evdev_client *client = file->private_data;
 399         struct evdev *evdev = client->evdev;
 400         struct input_event event;
 401         size_t read = 0;
 402         int error;
 403
 404         if (count != 0 && count < input_event_size())
 405                 return -EINVAL;
 406
 407         for (;;) {
 408                 if (!evdev->exist)
 409                         return -ENODEV;
 410
 411                 if (client->packet_head == client->tail &&
 412                     (file->f_flags & O_NONBLOCK))
 413                         return -EAGAIN;
 414
 415                 /*
 416                  * count == 0 is special - no IO is done but we check
 417                  * for error conditions (see above).
 418                  */
 419                 if (count == 0)
 420                         break;
 421
 422                 while (read + input_event_size() <= count &&
 423                        evdev_fetch_next_event(client, &event)) {
 424
 425                         if (input_event_to_user(buffer + read, &event))
 426                                 return -EFAULT;
 427
 428                         read += input_event_size();
 429                 }
 430
 431                 if (read)
 432                         break;
 433
 434                 if (!(file->f_flags & O_NONBLOCK)) {
 435                         error = wait_event_interruptible(evdev->wait,
 436                                         client->packet_head != client->tail ||
 437                                         !evdev->exist);
 438                         if (error)
 439                                 return error;
 440                 }
 441         }
 442
 443         return read;
 444 }
 445
 446 /* No kernel lock - fine */
 447 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 448 {
 449         struct evdev_client *client = file->private_data;
 450         struct evdev *evdev = client->evdev;
 451         unsigned int mask;
 452
 453         poll_wait(file, &evdev->wait, wait);
 454
 455         mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
 456         if (client->packet_head != client->tail)
 457                 mask |= POLLIN | POLLRDNORM;
 458
 459         return mask;
 460 }
 461
 462 #ifdef CONFIG_COMPAT
 463
 464 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 465 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 466
 467 #ifdef __BIG_ENDIAN
 468 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 469                         unsigned int maxlen, void __user *p, int compat)
 470 {
 471         int len, i;
 472
 473         if (compat) {
 474                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 475                 if (len > maxlen)
 476                         len = maxlen;
 477
 478                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 479                         if (copy_to_user((compat_long_t __user *) p + i,
 480                                          (compat_long_t *) bits +
 481                                                 i + 1 - ((i % 2) << 1),
 482                                          sizeof(compat_long_t)))
 483                                 return -EFAULT;
 484         } else {
 485                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 486                 if (len > maxlen)
 487                         len = maxlen;
 488
 489                 if (copy_to_user(p, bits, len))
 490                         return -EFAULT;
 491         }
 492
 493         return len;
 494 }
 495 #else
 496 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 497                         unsigned int maxlen, void __user *p, int compat)
 498 {
 499         int len = compat ?
 500                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 501                         BITS_TO_LONGS(maxbit) * sizeof(long);
 502
 503         if (len > maxlen)
 504                 len = maxlen;
 505
 506         return copy_to_user(p, bits, len) ? -EFAULT : len;
 507 }
 508 #endif /* __BIG_ENDIAN */
 509
 510 #else
 511
 512 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 513                         unsigned int maxlen, void __user *p, int compat)
 514 {
 515         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 516
 517         if (len > maxlen)
 518                 len = maxlen;
 519
 520         return copy_to_user(p, bits, len) ? -EFAULT : len;
 521 }
 522
 523 #endif /* CONFIG_COMPAT */
 524
 525 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 526 {
 527         int len;
 528
 529         if (!str)
 530                 return -ENOENT;
 531
 532         len = strlen(str) + 1;
 533         if (len > maxlen)
 534                 len = maxlen;
 535
 536         return copy_to_user(p, str, len) ? -EFAULT : len;
 537 }
 538
 539 #define OLD_KEY_MAX     0x1ff
 540 static int handle_eviocgbit(struct input_dev *dev,
 541                             unsigned int type, unsigned int size,
 542                             void __user *p, int compat_mode)
 543 {
 544         static unsigned long keymax_warn_time;
 545         unsigned long *bits;
 546         int len;
 547
 548         switch (type) {
 549
 550         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 551         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 552         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 553         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 554         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 555         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 556         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 557         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 558         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 559         default: return -EINVAL;
 560         }
 561
 562         /*
 563          * Work around bugs in userspace programs that like to do
 564          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 565          * should be in bytes, not in bits.
 566          */
 567         if (type == EV_KEY && size == OLD_KEY_MAX) {
 568                 len = OLD_KEY_MAX;
 569                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 570                         pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
 571                                    "limiting output to %zu bytes. See "
 572                                    "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 573                                    OLD_KEY_MAX,
 574                                    BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 575         }
 576
 577         return bits_to_user(bits, len, size, p, compat_mode);
 578 }
 579 #undef OLD_KEY_MAX
 580
 581 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 582 {
 583         struct input_keymap_entry ke = {
 584                 .len    = sizeof(unsigned int),
 585                 .flags  = 0,
 586         };
 587         int __user *ip = (int __user *)p;
 588         int error;
 589
 590         /* legacy case */
 591         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 592                 return -EFAULT;
 593
 594         error = input_get_keycode(dev, &ke);
 595         if (error)
 596                 return error;
 597
 598         if (put_user(ke.keycode, ip + 1))
 599                 return -EFAULT;
 600
 601         return 0;
 602 }
 603
 604 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 605 {
 606         struct input_keymap_entry ke;
 607         int error;
 608
 609         if (copy_from_user(&ke, p, sizeof(ke)))
 610                 return -EFAULT;
 611
 612         error = input_get_keycode(dev, &ke);
 613         if (error)
 614                 return error;
 615
 616         if (copy_to_user(p, &ke, sizeof(ke)))
 617                 return -EFAULT;
 618
 619         return 0;
 620 }
 621
 622 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 623 {
 624         struct input_keymap_entry ke = {
 625                 .len    = sizeof(unsigned int),
 626                 .flags  = 0,
 627         };
 628         int __user *ip = (int __user *)p;
 629
 630         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 631                 return -EFAULT;
 632
 633         if (get_user(ke.keycode, ip + 1))
 634                 return -EFAULT;
 635
 636         return input_set_keycode(dev, &ke);
 637 }
 638
 639 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 640 {
 641         struct input_keymap_entry ke;
 642
 643         if (copy_from_user(&ke, p, sizeof(ke)))
 644                 return -EFAULT;
 645
 646         if (ke.len > sizeof(ke.scancode))
 647                 return -EINVAL;
 648
 649         return input_set_keycode(dev, &ke);
 650 }
 651
 652 static int evdev_handle_mt_request(struct input_dev *dev,
 653                                    unsigned int size,
 654                                    int __user *ip)
 655 {
 656         const struct input_mt *mt = dev->mt;
 657         unsigned int code;
 658         int max_slots;
 659         int i;
 660
 661         if (get_user(code, &ip[0]))
 662                 return -EFAULT;
 663         if (!mt || !input_is_mt_value(code))
 664                 return -EINVAL;
 665
 666         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 667         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 668                 int value = input_mt_get_value(&mt->slots[i], code);
 669                 if (put_user(value, &ip[1 + i]))
 670                         return -EFAULT;
 671         }
 672
 673         return 0;
 674 }
 675
 676 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 677                            void __user *p, int compat_mode)
 678 {
 679         struct evdev_client *client = file->private_data;
 680         struct evdev *evdev = client->evdev;
 681         struct input_dev *dev = evdev->handle.dev;
 682         struct input_absinfo abs;
 683         struct ff_effect effect;
 684         int __user *ip = (int __user *)p;
 685         unsigned int i, t, u, v;
 686         unsigned int size;
 687         int error;
 688
 689         /* First we check for fixed-length commands */
 690         switch (cmd) {
 691
 692         case EVIOCGVERSION:
 693                 return put_user(EV_VERSION, ip);
 694
 695         case EVIOCGID:
 696                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 697                         return -EFAULT;
 698                 return 0;
 699
 700         case EVIOCGREP:
 701                 if (!test_bit(EV_REP, dev->evbit))
 702                         return -ENOSYS;
 703                 if (put_user(dev->rep[REP_DELAY], ip))
 704                         return -EFAULT;
 705                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 706                         return -EFAULT;
 707                 return 0;
 708
 709         case EVIOCSREP:
 710                 if (!test_bit(EV_REP, dev->evbit))
 711                         return -ENOSYS;
 712                 if (get_user(u, ip))
 713                         return -EFAULT;
 714                 if (get_user(v, ip + 1))
 715                         return -EFAULT;
 716
 717                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 718                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 719
 720                 return 0;
 721
 722         case EVIOCRMFF:
 723                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 724
 725         case EVIOCGEFFECTS:
 726                 i = test_bit(EV_FF, dev->evbit) ?
 727                                 dev->ff->max_effects : 0;
 728                 if (put_user(i, ip))
 729                         return -EFAULT;
 730                 return 0;
 731
 732         case EVIOCGRAB:
 733                 if (p)
 734                         return evdev_grab(evdev, client);
 735                 else
 736                         return evdev_ungrab(evdev, client);
 737
 738         case EVIOCSCLOCKID:
 739                 if (copy_from_user(&i, p, sizeof(unsigned int)))
 740                         return -EFAULT;
 741                 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
 742                         return -EINVAL;
 743                 client->clkid = i;
 744                 return 0;
 745
 746         case EVIOCGKEYCODE:
 747                 return evdev_handle_get_keycode(dev, p);
 748
 749         case EVIOCSKEYCODE:
 750                 return evdev_handle_set_keycode(dev, p);
 751
 752         case EVIOCGKEYCODE_V2:
 753                 return evdev_handle_get_keycode_v2(dev, p);
 754
 755         case EVIOCSKEYCODE_V2:
 756                 return evdev_handle_set_keycode_v2(dev, p);
 757         }
 758
 759         size = _IOC_SIZE(cmd);
 760
 761         /* Now check variable-length commands */
 762 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
 763         switch (EVIOC_MASK_SIZE(cmd)) {
 764
 765         case EVIOCGPROP(0):
 766                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
 767                                     size, p, compat_mode);
 768
 769         case EVIOCGMTSLOTS(0):
 770                 return evdev_handle_mt_request(dev, size, ip);
 771
 772         case EVIOCGKEY(0):
 773                 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
 774
 775         case EVIOCGLED(0):
 776                 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
 777
 778         case EVIOCGSND(0):
 779                 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
 780
 781         case EVIOCGSW(0):
 782                 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
 783
 784         case EVIOCGNAME(0):
 785                 return str_to_user(dev->name, size, p);
 786
 787         case EVIOCGPHYS(0):
 788                 return str_to_user(dev->phys, size, p);
 789
 790         case EVIOCGUNIQ(0):
 791                 return str_to_user(dev->uniq, size, p);
 792
 793         case EVIOC_MASK_SIZE(EVIOCSFF):
 794                 if (input_ff_effect_from_user(p, size, &effect))
 795                         return -EFAULT;
 796
 797                 error = input_ff_upload(dev, &effect, file);
 798
 799                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 800                         return -EFAULT;
 801
 802                 return error;
 803         }
 804
 805         /* Multi-number variable-length handlers */
 806         if (_IOC_TYPE(cmd) != 'E')
 807                 return -EINVAL;
 808
 809         if (_IOC_DIR(cmd) == _IOC_READ) {
 810
 811                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 812                         return handle_eviocgbit(dev,
 813                                                 _IOC_NR(cmd) & EV_MAX, size,
 814                                                 p, compat_mode);
 815
 816                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 817
 818                         if (!dev->absinfo)
 819                                 return -EINVAL;
 820
 821                         t = _IOC_NR(cmd) & ABS_MAX;
 822                         abs = dev->absinfo[t];
 823
 824                         if (copy_to_user(p, &abs, min_t(size_t,
 825                                         size, sizeof(struct input_absinfo))))
 826                                 return -EFAULT;
 827
 828                         return 0;
 829                 }
 830         }
 831
 832         if (_IOC_DIR(cmd) == _IOC_WRITE) {
 833
 834                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 835
 836                         if (!dev->absinfo)
 837                                 return -EINVAL;
 838
 839                         t = _IOC_NR(cmd) & ABS_MAX;
 840
 841                         if (copy_from_user(&abs, p, min_t(size_t,
 842                                         size, sizeof(struct input_absinfo))))
 843                                 return -EFAULT;
 844
 845                         if (size < sizeof(struct input_absinfo))
 846                                 abs.resolution = 0;
 847
 848                         /* We can't change number of reserved MT slots */
 849                         if (t == ABS_MT_SLOT)
 850                                 return -EINVAL;
 851
 852                         /*
 853                          * Take event lock to ensure that we are not
 854                          * changing device parameters in the middle
 855                          * of event.
 856                          */
 857                         spin_lock_irq(&dev->event_lock);
 858                         dev->absinfo[t] = abs;
 859                         spin_unlock_irq(&dev->event_lock);
 860
 861                         return 0;
 862                 }
 863         }
 864
 865         return -EINVAL;
 866 }
 867
 868 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 869                                 void __user *p, int compat_mode)
 870 {
 871         struct evdev_client *client = file->private_data;
 872         struct evdev *evdev = client->evdev;
 873         int retval;
 874
 875         retval = mutex_lock_interruptible(&evdev->mutex);
 876         if (retval)
 877                 return retval;
 878
 879         if (!evdev->exist) {
 880                 retval = -ENODEV;
 881                 goto out;
 882         }
 883
 884         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 885
 886  out:
 887         mutex_unlock(&evdev->mutex);
 888         return retval;
 889 }
 890
 891 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 892 {
 893         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 894 }
 895
 896 #ifdef CONFIG_COMPAT
 897 static long evdev_ioctl_compat(struct file *file,
 898                                 unsigned int cmd, unsigned long arg)
 899 {
 900         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 901 }
 902 #endif
 903
 904 static const struct file_operations evdev_fops = {
 905         .owner          = THIS_MODULE,
 906         .read           = evdev_read,
 907         .write          = evdev_write,
 908         .poll           = evdev_poll,
 909         .open           = evdev_open,
 910         .release        = evdev_release,
 911         .unlocked_ioctl = evdev_ioctl,
 912 #ifdef CONFIG_COMPAT
 913         .compat_ioctl   = evdev_ioctl_compat,
 914 #endif
 915         .fasync         = evdev_fasync,
 916         .flush          = evdev_flush,
 917         .llseek         = no_llseek,
 918 };
 919
 920 static int evdev_install_chrdev(struct evdev *evdev)
 921 {
 922         /*
 923          * No need to do any locking here as calls to connect and
 924          * disconnect are serialized by the input core
 925          */
 926         evdev_table[evdev->minor] = evdev;
 927         return 0;
 928 }
 929
 930 static void evdev_remove_chrdev(struct evdev *evdev)
 931 {
 932         /*
 933          * Lock evdev table to prevent race with evdev_open()
 934          */
 935         mutex_lock(&evdev_table_mutex);
 936         evdev_table[evdev->minor] = NULL;
 937         mutex_unlock(&evdev_table_mutex);
 938 }
 939
 940 /*
 941  * Mark device non-existent. This disables writes, ioctls and
 942  * prevents new users from opening the device. Already posted
 943  * blocking reads will stay, however new ones will fail.
 944  */
 945 static void evdev_mark_dead(struct evdev *evdev)
 946 {
 947         mutex_lock(&evdev->mutex);
 948         evdev->exist = false;
 949         mutex_unlock(&evdev->mutex);
 950 }
 951
 952 static void evdev_cleanup(struct evdev *evdev)
 953 {
 954         struct input_handle *handle = &evdev->handle;
 955
 956         evdev_mark_dead(evdev);
 957         evdev_hangup(evdev);
 958         evdev_remove_chrdev(evdev);
 959
 960         /* evdev is marked dead so no one else accesses evdev->open */
 961         if (evdev->open) {
 962                 input_flush_device(handle, NULL);
 963                 input_close_device(handle);
 964         }
 965 }
 966
 967 /*
 968  * Create new evdev device. Note that input core serializes calls
 969  * to connect and disconnect so we don't need to lock evdev_table here.
 970  */
 971 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 972                          const struct input_device_id *id)
 973 {
 974         struct evdev *evdev;
 975         int minor;
 976         int error;
 977
 978         for (minor = 0; minor < EVDEV_MINORS; minor++)
 979                 if (!evdev_table[minor])
 980                         break;
 981
 982         if (minor == EVDEV_MINORS) {
 983                 pr_err("no more free evdev devices\n");
 984                 return -ENFILE;
 985         }
 986
 987         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 988         if (!evdev)
 989                 return -ENOMEM;
 990
 991         INIT_LIST_HEAD(&evdev->client_list);
 992         spin_lock_init(&evdev->client_lock);
 993         mutex_init(&evdev->mutex);
 994         init_waitqueue_head(&evdev->wait);
 995
 996         dev_set_name(&evdev->dev, "event%d", minor);
 997         evdev->exist = true;
 998         evdev->minor = minor;
 999
1000         evdev->handle.dev = input_get_device(dev);
1001         evdev->handle.name = dev_name(&evdev->dev);
1002         evdev->handle.handler = handler;
1003         evdev->handle.private = evdev;
1004
1005         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
1006         evdev->dev.class = &input_class;
1007         evdev->dev.parent = &dev->dev;
1008         evdev->dev.release = evdev_free;
1009         device_initialize(&evdev->dev);
1010
1011         error = input_register_handle(&evdev->handle);
1012         if (error)
1013                 goto err_free_evdev;
1014
1015         error = evdev_install_chrdev(evdev);
1016         if (error)
1017                 goto err_unregister_handle;
1018
1019         error = device_add(&evdev->dev);
1020         if (error)
1021                 goto err_cleanup_evdev;
1022
1023         return 0;
1024
1025  err_cleanup_evdev:
1026         evdev_cleanup(evdev);
1027  err_unregister_handle:
1028         input_unregister_handle(&evdev->handle);
1029  err_free_evdev:
1030         put_device(&evdev->dev);
1031         return error;
1032 }
1033
1034 static void evdev_disconnect(struct input_handle *handle)
1035 {
1036         struct evdev *evdev = handle->private;
1037
1038         device_del(&evdev->dev);
1039         evdev_cleanup(evdev);
1040         input_unregister_handle(handle);
1041         put_device(&evdev->dev);
1042 }
1043
1044 static const struct input_device_id evdev_ids[] = {
1045         { .driver_info = 1 },   /* Matches all devices */
1046         { },                    /* Terminating zero entry */
1047 };
1048
1049 MODULE_DEVICE_TABLE(input, evdev_ids);
1050
1051 static struct input_handler evdev_handler = {
1052         .event          = evdev_event,
1053         .connect        = evdev_connect,
1054         .disconnect     = evdev_disconnect,
1055         .fops           = &evdev_fops,
1056         .minor          = EVDEV_MINOR_BASE,
1057         .name           = "evdev",
1058         .id_table       = evdev_ids,
1059 };
1060
1061 static int __init evdev_init(void)
1062 {
1063         return input_register_handler(&evdev_handler);
1064 }
1065
1066 static void __exit evdev_exit(void)
1067 {
1068         input_unregister_handler(&evdev_handler);
1069 }
1070
1071 module_init(evdev_init);
1072 module_exit(evdev_exit);
1073
1074 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1075 MODULE_DESCRIPTION("Input driver event char devices");
1076 MODULE_LICENSE("GPL");