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