Pileus Git - ~andy/linux/blob - 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         put_device(&evdev->dev);
 296
 297         return 0;
 298 }
 299
 300 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 301 {
 302         unsigned int n_events =
 303                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 304                     EVDEV_MIN_BUFFER_SIZE);
 305
 306         return roundup_pow_of_two(n_events);
 307 }
 308
 309 static int evdev_open(struct inode *inode, struct file *file)
 310 {
 311         struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
 312         unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 313         struct evdev_client *client;
 314         int error;
 315
 316         client = kzalloc(sizeof(struct evdev_client) +
 317                                 bufsize * sizeof(struct input_event),
 318                          GFP_KERNEL);
 319         if (!client)
 320                 return -ENOMEM;
 321
 322         client->bufsize = bufsize;
 323         spin_lock_init(&client->buffer_lock);
 324         client->evdev = evdev;
 325         evdev_attach_client(evdev, client);
 326
 327         error = evdev_open_device(evdev);
 328         if (error)
 329                 goto err_free_client;
 330
 331         file->private_data = client;
 332         nonseekable_open(inode, file);
 333
 334         get_device(&evdev->dev);
 335         return 0;
 336
 337  err_free_client:
 338         evdev_detach_client(evdev, client);
 339         kfree(client);
 340         return error;
 341 }
 342
 343 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 344                            size_t count, loff_t *ppos)
 345 {
 346         struct evdev_client *client = file->private_data;
 347         struct evdev *evdev = client->evdev;
 348         struct input_event event;
 349         int retval = 0;
 350
 351         if (count != 0 && count < input_event_size())
 352                 return -EINVAL;
 353
 354         retval = mutex_lock_interruptible(&evdev->mutex);
 355         if (retval)
 356                 return retval;
 357
 358         if (!evdev->exist) {
 359                 retval = -ENODEV;
 360                 goto out;
 361         }
 362
 363         while (retval + input_event_size() <= count) {
 364
 365                 if (input_event_from_user(buffer + retval, &event)) {
 366                         retval = -EFAULT;
 367                         goto out;
 368                 }
 369                 retval += input_event_size();
 370
 371                 input_inject_event(&evdev->handle,
 372                                    event.type, event.code, event.value);
 373         }
 374
 375  out:
 376         mutex_unlock(&evdev->mutex);
 377         return retval;
 378 }
 379
 380 static int evdev_fetch_next_event(struct evdev_client *client,
 381                                   struct input_event *event)
 382 {
 383         int have_event;
 384
 385         spin_lock_irq(&client->buffer_lock);
 386
 387         have_event = client->packet_head != client->tail;
 388         if (have_event) {
 389                 *event = client->buffer[client->tail++];
 390                 client->tail &= client->bufsize - 1;
 391         }
 392
 393         spin_unlock_irq(&client->buffer_lock);
 394
 395         return have_event;
 396 }
 397
 398 static ssize_t evdev_read(struct file *file, char __user *buffer,
 399                           size_t count, loff_t *ppos)
 400 {
 401         struct evdev_client *client = file->private_data;
 402         struct evdev *evdev = client->evdev;
 403         struct input_event event;
 404         size_t read = 0;
 405         int error;
 406
 407         if (count != 0 && count < input_event_size())
 408                 return -EINVAL;
 409
 410         for (;;) {
 411                 if (!evdev->exist)
 412                         return -ENODEV;
 413
 414                 if (client->packet_head == client->tail &&
 415                     (file->f_flags & O_NONBLOCK))
 416                         return -EAGAIN;
 417
 418                 /*
 419                  * count == 0 is special - no IO is done but we check
 420                  * for error conditions (see above).
 421                  */
 422                 if (count == 0)
 423                         break;
 424
 425                 while (read + input_event_size() <= count &&
 426                        evdev_fetch_next_event(client, &event)) {
 427
 428                         if (input_event_to_user(buffer + read, &event))
 429                                 return -EFAULT;
 430
 431                         read += input_event_size();
 432                 }
 433
 434                 if (read)
 435                         break;
 436
 437                 if (!(file->f_flags & O_NONBLOCK)) {
 438                         error = wait_event_interruptible(evdev->wait,
 439                                         client->packet_head != client->tail ||
 440                                         !evdev->exist);
 441                         if (error)
 442                                 return error;
 443                 }
 444         }
 445
 446         return read;
 447 }
 448
 449 /* No kernel lock - fine */
 450 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 451 {
 452         struct evdev_client *client = file->private_data;
 453         struct evdev *evdev = client->evdev;
 454         unsigned int mask;
 455
 456         poll_wait(file, &evdev->wait, wait);
 457
 458         mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
 459         if (client->packet_head != client->tail)
 460                 mask |= POLLIN | POLLRDNORM;
 461
 462         return mask;
 463 }
 464
 465 #ifdef CONFIG_COMPAT
 466
 467 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 468 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 469
 470 #ifdef __BIG_ENDIAN
 471 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 472                         unsigned int maxlen, void __user *p, int compat)
 473 {
 474         int len, i;
 475
 476         if (compat) {
 477                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 478                 if (len > maxlen)
 479                         len = maxlen;
 480
 481                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 482                         if (copy_to_user((compat_long_t __user *) p + i,
 483                                          (compat_long_t *) bits +
 484                                                 i + 1 - ((i % 2) << 1),
 485                                          sizeof(compat_long_t)))
 486                                 return -EFAULT;
 487         } else {
 488                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 489                 if (len > maxlen)
 490                         len = maxlen;
 491
 492                 if (copy_to_user(p, bits, len))
 493                         return -EFAULT;
 494         }
 495
 496         return len;
 497 }
 498 #else
 499 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 500                         unsigned int maxlen, void __user *p, int compat)
 501 {
 502         int len = compat ?
 503                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 504                         BITS_TO_LONGS(maxbit) * sizeof(long);
 505
 506         if (len > maxlen)
 507                 len = maxlen;
 508
 509         return copy_to_user(p, bits, len) ? -EFAULT : len;
 510 }
 511 #endif /* __BIG_ENDIAN */
 512
 513 #else
 514
 515 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 516                         unsigned int maxlen, void __user *p, int compat)
 517 {
 518         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 519
 520         if (len > maxlen)
 521                 len = maxlen;
 522
 523         return copy_to_user(p, bits, len) ? -EFAULT : len;
 524 }
 525
 526 #endif /* CONFIG_COMPAT */
 527
 528 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 529 {
 530         int len;
 531
 532         if (!str)
 533                 return -ENOENT;
 534
 535         len = strlen(str) + 1;
 536         if (len > maxlen)
 537                 len = maxlen;
 538
 539         return copy_to_user(p, str, len) ? -EFAULT : len;
 540 }
 541
 542 #define OLD_KEY_MAX     0x1ff
 543 static int handle_eviocgbit(struct input_dev *dev,
 544                             unsigned int type, unsigned int size,
 545                             void __user *p, int compat_mode)
 546 {
 547         static unsigned long keymax_warn_time;
 548         unsigned long *bits;
 549         int len;
 550
 551         switch (type) {
 552
 553         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 554         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 555         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 556         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 557         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 558         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 559         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 560         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 561         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 562         default: return -EINVAL;
 563         }
 564
 565         /*
 566          * Work around bugs in userspace programs that like to do
 567          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 568          * should be in bytes, not in bits.
 569          */
 570         if (type == EV_KEY && size == OLD_KEY_MAX) {
 571                 len = OLD_KEY_MAX;
 572                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 573                         pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
 574                                    "limiting output to %zu bytes. See "
 575                                    "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 576                                    OLD_KEY_MAX,
 577                                    BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 578         }
 579
 580         return bits_to_user(bits, len, size, p, compat_mode);
 581 }
 582 #undef OLD_KEY_MAX
 583
 584 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 585 {
 586         struct input_keymap_entry ke = {
 587                 .len    = sizeof(unsigned int),
 588                 .flags  = 0,
 589         };
 590         int __user *ip = (int __user *)p;
 591         int error;
 592
 593         /* legacy case */
 594         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 595                 return -EFAULT;
 596
 597         error = input_get_keycode(dev, &ke);
 598         if (error)
 599                 return error;
 600
 601         if (put_user(ke.keycode, ip + 1))
 602                 return -EFAULT;
 603
 604         return 0;
 605 }
 606
 607 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 608 {
 609         struct input_keymap_entry ke;
 610         int error;
 611
 612         if (copy_from_user(&ke, p, sizeof(ke)))
 613                 return -EFAULT;
 614
 615         error = input_get_keycode(dev, &ke);
 616         if (error)
 617                 return error;
 618
 619         if (copy_to_user(p, &ke, sizeof(ke)))
 620                 return -EFAULT;
 621
 622         return 0;
 623 }
 624
 625 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 626 {
 627         struct input_keymap_entry ke = {
 628                 .len    = sizeof(unsigned int),
 629                 .flags  = 0,
 630         };
 631         int __user *ip = (int __user *)p;
 632
 633         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 634                 return -EFAULT;
 635
 636         if (get_user(ke.keycode, ip + 1))
 637                 return -EFAULT;
 638
 639         return input_set_keycode(dev, &ke);
 640 }
 641
 642 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 643 {
 644         struct input_keymap_entry ke;
 645
 646         if (copy_from_user(&ke, p, sizeof(ke)))
 647                 return -EFAULT;
 648
 649         if (ke.len > sizeof(ke.scancode))
 650                 return -EINVAL;
 651
 652         return input_set_keycode(dev, &ke);
 653 }
 654
 655 static int evdev_handle_mt_request(struct input_dev *dev,
 656                                    unsigned int size,
 657                                    int __user *ip)
 658 {
 659         const struct input_mt *mt = dev->mt;
 660         unsigned int code;
 661         int max_slots;
 662         int i;
 663
 664         if (get_user(code, &ip[0]))
 665                 return -EFAULT;
 666         if (!mt || !input_is_mt_value(code))
 667                 return -EINVAL;
 668
 669         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 670         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 671                 int value = input_mt_get_value(&mt->slots[i], code);
 672                 if (put_user(value, &ip[1 + i]))
 673                         return -EFAULT;
 674         }
 675
 676         return 0;
 677 }
 678
 679 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 680                            void __user *p, int compat_mode)
 681 {
 682         struct evdev_client *client = file->private_data;
 683         struct evdev *evdev = client->evdev;
 684         struct input_dev *dev = evdev->handle.dev;
 685         struct input_absinfo abs;
 686         struct ff_effect effect;
 687         int __user *ip = (int __user *)p;
 688         unsigned int i, t, u, v;
 689         unsigned int size;
 690         int error;
 691
 692         /* First we check for fixed-length commands */
 693         switch (cmd) {
 694
 695         case EVIOCGVERSION:
 696                 return put_user(EV_VERSION, ip);
 697
 698         case EVIOCGID:
 699                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 700                         return -EFAULT;
 701                 return 0;
 702
 703         case EVIOCGREP:
 704                 if (!test_bit(EV_REP, dev->evbit))
 705                         return -ENOSYS;
 706                 if (put_user(dev->rep[REP_DELAY], ip))
 707                         return -EFAULT;
 708                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 709                         return -EFAULT;
 710                 return 0;
 711
 712         case EVIOCSREP:
 713                 if (!test_bit(EV_REP, dev->evbit))
 714                         return -ENOSYS;
 715                 if (get_user(u, ip))
 716                         return -EFAULT;
 717                 if (get_user(v, ip + 1))
 718                         return -EFAULT;
 719
 720                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 721                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 722
 723                 return 0;
 724
 725         case EVIOCRMFF:
 726                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 727
 728         case EVIOCGEFFECTS:
 729                 i = test_bit(EV_FF, dev->evbit) ?
 730                                 dev->ff->max_effects : 0;
 731                 if (put_user(i, ip))
 732                         return -EFAULT;
 733                 return 0;
 734
 735         case EVIOCGRAB:
 736                 if (p)
 737                         return evdev_grab(evdev, client);
 738                 else
 739                         return evdev_ungrab(evdev, client);
 740
 741         case EVIOCSCLOCKID:
 742                 if (copy_from_user(&i, p, sizeof(unsigned int)))
 743                         return -EFAULT;
 744                 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
 745                         return -EINVAL;
 746                 client->clkid = i;
 747                 return 0;
 748
 749         case EVIOCGKEYCODE:
 750                 return evdev_handle_get_keycode(dev, p);
 751
 752         case EVIOCSKEYCODE:
 753                 return evdev_handle_set_keycode(dev, p);
 754
 755         case EVIOCGKEYCODE_V2:
 756                 return evdev_handle_get_keycode_v2(dev, p);
 757
 758         case EVIOCSKEYCODE_V2:
 759                 return evdev_handle_set_keycode_v2(dev, p);
 760         }
 761
 762         size = _IOC_SIZE(cmd);
 763
 764         /* Now check variable-length commands */
 765 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
 766         switch (EVIOC_MASK_SIZE(cmd)) {
 767
 768         case EVIOCGPROP(0):
 769                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
 770                                     size, p, compat_mode);
 771
 772         case EVIOCGMTSLOTS(0):
 773                 return evdev_handle_mt_request(dev, size, ip);
 774
 775         case EVIOCGKEY(0):
 776                 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
 777
 778         case EVIOCGLED(0):
 779                 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
 780
 781         case EVIOCGSND(0):
 782                 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
 783
 784         case EVIOCGSW(0):
 785                 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
 786
 787         case EVIOCGNAME(0):
 788                 return str_to_user(dev->name, size, p);
 789
 790         case EVIOCGPHYS(0):
 791                 return str_to_user(dev->phys, size, p);
 792
 793         case EVIOCGUNIQ(0):
 794                 return str_to_user(dev->uniq, size, p);
 795
 796         case EVIOC_MASK_SIZE(EVIOCSFF):
 797                 if (input_ff_effect_from_user(p, size, &effect))
 798                         return -EFAULT;
 799
 800                 error = input_ff_upload(dev, &effect, file);
 801
 802                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 803                         return -EFAULT;
 804
 805                 return error;
 806         }
 807
 808         /* Multi-number variable-length handlers */
 809         if (_IOC_TYPE(cmd) != 'E')
 810                 return -EINVAL;
 811
 812         if (_IOC_DIR(cmd) == _IOC_READ) {
 813
 814                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 815                         return handle_eviocgbit(dev,
 816                                                 _IOC_NR(cmd) & EV_MAX, size,
 817                                                 p, compat_mode);
 818
 819                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 820
 821                         if (!dev->absinfo)
 822                                 return -EINVAL;
 823
 824                         t = _IOC_NR(cmd) & ABS_MAX;
 825                         abs = dev->absinfo[t];
 826
 827                         if (copy_to_user(p, &abs, min_t(size_t,
 828                                         size, sizeof(struct input_absinfo))))
 829                                 return -EFAULT;
 830
 831                         return 0;
 832                 }
 833         }
 834
 835         if (_IOC_DIR(cmd) == _IOC_WRITE) {
 836
 837                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 838
 839                         if (!dev->absinfo)
 840                                 return -EINVAL;
 841
 842                         t = _IOC_NR(cmd) & ABS_MAX;
 843
 844                         if (copy_from_user(&abs, p, min_t(size_t,
 845                                         size, sizeof(struct input_absinfo))))
 846                                 return -EFAULT;
 847
 848                         if (size < sizeof(struct input_absinfo))
 849                                 abs.resolution = 0;
 850
 851                         /* We can't change number of reserved MT slots */
 852                         if (t == ABS_MT_SLOT)
 853                                 return -EINVAL;
 854
 855                         /*
 856                          * Take event lock to ensure that we are not
 857                          * changing device parameters in the middle
 858                          * of event.
 859                          */
 860                         spin_lock_irq(&dev->event_lock);
 861                         dev->absinfo[t] = abs;
 862                         spin_unlock_irq(&dev->event_lock);
 863
 864                         return 0;
 865                 }
 866         }
 867
 868         return -EINVAL;
 869 }
 870
 871 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 872                                 void __user *p, int compat_mode)
 873 {
 874         struct evdev_client *client = file->private_data;
 875         struct evdev *evdev = client->evdev;
 876         int retval;
 877
 878         retval = mutex_lock_interruptible(&evdev->mutex);
 879         if (retval)
 880                 return retval;
 881
 882         if (!evdev->exist) {
 883                 retval = -ENODEV;
 884                 goto out;
 885         }
 886
 887         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 888
 889  out:
 890         mutex_unlock(&evdev->mutex);
 891         return retval;
 892 }
 893
 894 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 895 {
 896         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 897 }
 898
 899 #ifdef CONFIG_COMPAT
 900 static long evdev_ioctl_compat(struct file *file,
 901                                 unsigned int cmd, unsigned long arg)
 902 {
 903         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 904 }
 905 #endif
 906
 907 static const struct file_operations evdev_fops = {
 908         .owner          = THIS_MODULE,
 909         .read           = evdev_read,
 910         .write          = evdev_write,
 911         .poll           = evdev_poll,
 912         .open           = evdev_open,
 913         .release        = evdev_release,
 914         .unlocked_ioctl = evdev_ioctl,
 915 #ifdef CONFIG_COMPAT
 916         .compat_ioctl   = evdev_ioctl_compat,
 917 #endif
 918         .fasync         = evdev_fasync,
 919         .flush          = evdev_flush,
 920         .llseek         = no_llseek,
 921 };
 922
 923 /*
 924  * Mark device non-existent. This disables writes, ioctls and
 925  * prevents new users from opening the device. Already posted
 926  * blocking reads will stay, however new ones will fail.
 927  */
 928 static void evdev_mark_dead(struct evdev *evdev)
 929 {
 930         mutex_lock(&evdev->mutex);
 931         evdev->exist = false;
 932         mutex_unlock(&evdev->mutex);
 933 }
 934
 935 static void evdev_cleanup(struct evdev *evdev)
 936 {
 937         struct input_handle *handle = &evdev->handle;
 938
 939         evdev_mark_dead(evdev);
 940         evdev_hangup(evdev);
 941
 942         cdev_del(&evdev->cdev);
 943
 944         /* evdev is marked dead so no one else accesses evdev->open */
 945         if (evdev->open) {
 946                 input_flush_device(handle, NULL);
 947                 input_close_device(handle);
 948         }
 949 }
 950
 951 /*
 952  * Create new evdev device. Note that input core serializes calls
 953  * to connect and disconnect.
 954  */
 955 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 956                          const struct input_device_id *id)
 957 {
 958         struct evdev *evdev;
 959         int minor;
 960         int dev_no;
 961         int error;
 962
 963         minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
 964         if (minor < 0) {
 965                 error = minor;
 966                 pr_err("failed to reserve new minor: %d\n", error);
 967                 return error;
 968         }
 969
 970         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 971         if (!evdev) {
 972                 error = -ENOMEM;
 973                 goto err_free_minor;
 974         }
 975
 976         INIT_LIST_HEAD(&evdev->client_list);
 977         spin_lock_init(&evdev->client_lock);
 978         mutex_init(&evdev->mutex);
 979         init_waitqueue_head(&evdev->wait);
 980         evdev->exist = true;
 981
 982         dev_no = minor;
 983         /* Normalize device number if it falls into legacy range */
 984         if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
 985                 dev_no -= EVDEV_MINOR_BASE;
 986         dev_set_name(&evdev->dev, "event%d", dev_no);
 987
 988         evdev->handle.dev = input_get_device(dev);
 989         evdev->handle.name = dev_name(&evdev->dev);
 990         evdev->handle.handler = handler;
 991         evdev->handle.private = evdev;
 992
 993         evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
 994         evdev->dev.class = &input_class;
 995         evdev->dev.parent = &dev->dev;
 996         evdev->dev.release = evdev_free;
 997         device_initialize(&evdev->dev);
 998
 999         error = input_register_handle(&evdev->handle);
1000         if (error)
1001                 goto err_free_evdev;
1002
1003         cdev_init(&evdev->cdev, &evdev_fops);
1004         error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1005         if (error)
1006                 goto err_unregister_handle;
1007
1008         error = device_add(&evdev->dev);
1009         if (error)
1010                 goto err_cleanup_evdev;
1011
1012         return 0;
1013
1014  err_cleanup_evdev:
1015         evdev_cleanup(evdev);
1016  err_unregister_handle:
1017         input_unregister_handle(&evdev->handle);
1018  err_free_evdev:
1019         put_device(&evdev->dev);
1020  err_free_minor:
1021         input_free_minor(minor);
1022         return error;
1023 }
1024
1025 static void evdev_disconnect(struct input_handle *handle)
1026 {
1027         struct evdev *evdev = handle->private;
1028
1029         device_del(&evdev->dev);
1030         evdev_cleanup(evdev);
1031         input_free_minor(MINOR(evdev->dev.devt));
1032         input_unregister_handle(handle);
1033         put_device(&evdev->dev);
1034 }
1035
1036 static const struct input_device_id evdev_ids[] = {
1037         { .driver_info = 1 },   /* Matches all devices */
1038         { },                    /* Terminating zero entry */
1039 };
1040
1041 MODULE_DEVICE_TABLE(input, evdev_ids);
1042
1043 static struct input_handler evdev_handler = {
1044         .event          = evdev_event,
1045         .events         = evdev_events,
1046         .connect        = evdev_connect,
1047         .disconnect     = evdev_disconnect,
1048         .legacy_minors  = true,
1049         .minor          = EVDEV_MINOR_BASE,
1050         .name           = "evdev",
1051         .id_table       = evdev_ids,
1052 };
1053
1054 static int __init evdev_init(void)
1055 {
1056         return input_register_handler(&evdev_handler);
1057 }
1058
1059 static void __exit evdev_exit(void)
1060 {
1061         input_unregister_handler(&evdev_handler);
1062 }
1063
1064 module_init(evdev_init);
1065 module_exit(evdev_exit);
1066
1067 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1068 MODULE_DESCRIPTION("Input driver event char devices");
1069 MODULE_LICENSE("GPL");