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 "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 __pass_event(struct evdev_client *client,
  58                          const struct input_event *event)
  59 {
  60         client->buffer[client->head++] = *event;
  61         client->head &= client->bufsize - 1;
  62
  63         if (unlikely(client->head == client->tail)) {
  64                 /*
  65                  * This effectively "drops" all unconsumed events, leaving
  66                  * EV_SYN/SYN_DROPPED plus the newest event in the queue.
  67                  */
  68                 client->tail = (client->head - 2) & (client->bufsize - 1);
  69
  70                 client->buffer[client->tail].time = event->time;
  71                 client->buffer[client->tail].type = EV_SYN;
  72                 client->buffer[client->tail].code = SYN_DROPPED;
  73                 client->buffer[client->tail].value = 0;
  74
  75                 client->packet_head = client->tail;
  76         }
  77
  78         if (event->type == EV_SYN && event->code == SYN_REPORT) {
  79                 client->packet_head = client->head;
  80                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
  81         }
  82 }
  83
  84 static void evdev_pass_values(struct evdev_client *client,
  85                         const struct input_value *vals, unsigned int count,
  86                         ktime_t mono, ktime_t real)
  87 {
  88         struct evdev *evdev = client->evdev;
  89         const struct input_value *v;
  90         struct input_event event;
  91         bool wakeup = false;
  92
  93         event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
  94                                       mono : real);
  95
  96         /* Interrupts are disabled, just acquire the lock. */
  97         spin_lock(&client->buffer_lock);
  98
  99         for (v = vals; v != vals + count; v++) {
 100                 event.type = v->type;
 101                 event.code = v->code;
 102                 event.value = v->value;
 103                 __pass_event(client, &event);
 104                 if (v->type == EV_SYN && v->code == SYN_REPORT)
 105                         wakeup = true;
 106         }
 107
 108         spin_unlock(&client->buffer_lock);
 109
 110         if (wakeup)
 111                 wake_up_interruptible(&evdev->wait);
 112 }
 113
 114 /*
 115  * Pass incoming events to all connected clients.
 116  */
 117 static void evdev_events(struct input_handle *handle,
 118                          const struct input_value *vals, unsigned int count)
 119 {
 120         struct evdev *evdev = handle->private;
 121         struct evdev_client *client;
 122         ktime_t time_mono, time_real;
 123
 124         time_mono = ktime_get();
 125         time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
 126
 127         rcu_read_lock();
 128
 129         client = rcu_dereference(evdev->grab);
 130
 131         if (client)
 132                 evdev_pass_values(client, vals, count, time_mono, time_real);
 133         else
 134                 list_for_each_entry_rcu(client, &evdev->client_list, node)
 135                         evdev_pass_values(client, vals, count,
 136                                           time_mono, time_real);
 137
 138         rcu_read_unlock();
 139 }
 140
 141 /*
 142  * Pass incoming event to all connected clients.
 143  */
 144 static void evdev_event(struct input_handle *handle,
 145                         unsigned int type, unsigned int code, int value)
 146 {
 147         struct input_value vals[] = { { type, code, value } };
 148
 149         evdev_events(handle, vals, 1);
 150 }
 151
 152 static int evdev_fasync(int fd, struct file *file, int on)
 153 {
 154         struct evdev_client *client = file->private_data;
 155
 156         return fasync_helper(fd, file, on, &client->fasync);
 157 }
 158
 159 static int evdev_flush(struct file *file, fl_owner_t id)
 160 {
 161         struct evdev_client *client = file->private_data;
 162         struct evdev *evdev = client->evdev;
 163         int retval;
 164
 165         retval = mutex_lock_interruptible(&evdev->mutex);
 166         if (retval)
 167                 return retval;
 168
 169         if (!evdev->exist)
 170                 retval = -ENODEV;
 171         else
 172                 retval = input_flush_device(&evdev->handle, file);
 173
 174         mutex_unlock(&evdev->mutex);
 175         return retval;
 176 }
 177
 178 static void evdev_free(struct device *dev)
 179 {
 180         struct evdev *evdev = container_of(dev, struct evdev, dev);
 181
 182         input_put_device(evdev->handle.dev);
 183         kfree(evdev);
 184 }
 185
 186 /*
 187  * Grabs an event device (along with underlying input device).
 188  * This function is called with evdev->mutex taken.
 189  */
 190 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 191 {
 192         int error;
 193
 194         if (evdev->grab)
 195                 return -EBUSY;
 196
 197         error = input_grab_device(&evdev->handle);
 198         if (error)
 199                 return error;
 200
 201         rcu_assign_pointer(evdev->grab, client);
 202
 203         return 0;
 204 }
 205
 206 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 207 {
 208         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
 209                                         lockdep_is_held(&evdev->mutex));
 210
 211         if (grab != client)
 212                 return  -EINVAL;
 213
 214         rcu_assign_pointer(evdev->grab, NULL);
 215         synchronize_rcu();
 216         input_release_device(&evdev->handle);
 217
 218         return 0;
 219 }
 220
 221 static void evdev_attach_client(struct evdev *evdev,
 222                                 struct evdev_client *client)
 223 {
 224         spin_lock(&evdev->client_lock);
 225         list_add_tail_rcu(&client->node, &evdev->client_list);
 226         spin_unlock(&evdev->client_lock);
 227 }
 228
 229 static void evdev_detach_client(struct evdev *evdev,
 230                                 struct evdev_client *client)
 231 {
 232         spin_lock(&evdev->client_lock);
 233         list_del_rcu(&client->node);
 234         spin_unlock(&evdev->client_lock);
 235         synchronize_rcu();
 236 }
 237
 238 static int evdev_open_device(struct evdev *evdev)
 239 {
 240         int retval;
 241
 242         retval = mutex_lock_interruptible(&evdev->mutex);
 243         if (retval)
 244                 return retval;
 245
 246         if (!evdev->exist)
 247                 retval = -ENODEV;
 248         else if (!evdev->open++) {
 249                 retval = input_open_device(&evdev->handle);
 250                 if (retval)
 251                         evdev->open--;
 252         }
 253
 254         mutex_unlock(&evdev->mutex);
 255         return retval;
 256 }
 257
 258 static void evdev_close_device(struct evdev *evdev)
 259 {
 260         mutex_lock(&evdev->mutex);
 261
 262         if (evdev->exist && !--evdev->open)
 263                 input_close_device(&evdev->handle);
 264
 265         mutex_unlock(&evdev->mutex);
 266 }
 267
 268 /*
 269  * Wake up users waiting for IO so they can disconnect from
 270  * dead device.
 271  */
 272 static void evdev_hangup(struct evdev *evdev)
 273 {
 274         struct evdev_client *client;
 275
 276         spin_lock(&evdev->client_lock);
 277         list_for_each_entry(client, &evdev->client_list, node)
 278                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 279         spin_unlock(&evdev->client_lock);
 280
 281         wake_up_interruptible(&evdev->wait);
 282 }
 283
 284 static int evdev_release(struct inode *inode, struct file *file)
 285 {
 286         struct evdev_client *client = file->private_data;
 287         struct evdev *evdev = client->evdev;
 288
 289         mutex_lock(&evdev->mutex);
 290         evdev_ungrab(evdev, client);
 291         mutex_unlock(&evdev->mutex);
 292
 293         evdev_detach_client(evdev, client);
 294         kfree(client);
 295
 296         evdev_close_device(evdev);
 297         put_device(&evdev->dev);
 298
 299         return 0;
 300 }
 301
 302 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
 303 {
 304         unsigned int n_events =
 305                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
 306                     EVDEV_MIN_BUFFER_SIZE);
 307
 308         return roundup_pow_of_two(n_events);
 309 }
 310
 311 static int evdev_open(struct inode *inode, struct file *file)
 312 {
 313         struct evdev *evdev;
 314         struct evdev_client *client;
 315         int i = iminor(inode) - EVDEV_MINOR_BASE;
 316         unsigned int bufsize;
 317         int error;
 318
 319         if (i >= EVDEV_MINORS)
 320                 return -ENODEV;
 321
 322         error = mutex_lock_interruptible(&evdev_table_mutex);
 323         if (error)
 324                 return error;
 325         evdev = evdev_table[i];
 326         if (evdev)
 327                 get_device(&evdev->dev);
 328         mutex_unlock(&evdev_table_mutex);
 329
 330         if (!evdev)
 331                 return -ENODEV;
 332
 333         bufsize = evdev_compute_buffer_size(evdev->handle.dev);
 334
 335         client = kzalloc(sizeof(struct evdev_client) +
 336                                 bufsize * sizeof(struct input_event),
 337                          GFP_KERNEL);
 338         if (!client) {
 339                 error = -ENOMEM;
 340                 goto err_put_evdev;
 341         }
 342
 343         client->bufsize = bufsize;
 344         spin_lock_init(&client->buffer_lock);
 345         client->evdev = evdev;
 346         evdev_attach_client(evdev, client);
 347
 348         error = evdev_open_device(evdev);
 349         if (error)
 350                 goto err_free_client;
 351
 352         file->private_data = client;
 353         nonseekable_open(inode, file);
 354
 355         return 0;
 356
 357  err_free_client:
 358         evdev_detach_client(evdev, client);
 359         kfree(client);
 360  err_put_evdev:
 361         put_device(&evdev->dev);
 362         return error;
 363 }
 364
 365 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 366                            size_t count, loff_t *ppos)
 367 {
 368         struct evdev_client *client = file->private_data;
 369         struct evdev *evdev = client->evdev;
 370         struct input_event event;
 371         int retval = 0;
 372
 373         if (count != 0 && count < input_event_size())
 374                 return -EINVAL;
 375
 376         retval = mutex_lock_interruptible(&evdev->mutex);
 377         if (retval)
 378                 return retval;
 379
 380         if (!evdev->exist) {
 381                 retval = -ENODEV;
 382                 goto out;
 383         }
 384
 385         while (retval + input_event_size() <= count) {
 386
 387                 if (input_event_from_user(buffer + retval, &event)) {
 388                         retval = -EFAULT;
 389                         goto out;
 390                 }
 391                 retval += input_event_size();
 392
 393                 input_inject_event(&evdev->handle,
 394                                    event.type, event.code, event.value);
 395         }
 396
 397  out:
 398         mutex_unlock(&evdev->mutex);
 399         return retval;
 400 }
 401
 402 static int evdev_fetch_next_event(struct evdev_client *client,
 403                                   struct input_event *event)
 404 {
 405         int have_event;
 406
 407         spin_lock_irq(&client->buffer_lock);
 408
 409         have_event = client->packet_head != client->tail;
 410         if (have_event) {
 411                 *event = client->buffer[client->tail++];
 412                 client->tail &= client->bufsize - 1;
 413         }
 414
 415         spin_unlock_irq(&client->buffer_lock);
 416
 417         return have_event;
 418 }
 419
 420 static ssize_t evdev_read(struct file *file, char __user *buffer,
 421                           size_t count, loff_t *ppos)
 422 {
 423         struct evdev_client *client = file->private_data;
 424         struct evdev *evdev = client->evdev;
 425         struct input_event event;
 426         size_t read = 0;
 427         int error;
 428
 429         if (count != 0 && count < input_event_size())
 430                 return -EINVAL;
 431
 432         for (;;) {
 433                 if (!evdev->exist)
 434                         return -ENODEV;
 435
 436                 if (client->packet_head == client->tail &&
 437                     (file->f_flags & O_NONBLOCK))
 438                         return -EAGAIN;
 439
 440                 /*
 441                  * count == 0 is special - no IO is done but we check
 442                  * for error conditions (see above).
 443                  */
 444                 if (count == 0)
 445                         break;
 446
 447                 while (read + input_event_size() <= count &&
 448                        evdev_fetch_next_event(client, &event)) {
 449
 450                         if (input_event_to_user(buffer + read, &event))
 451                                 return -EFAULT;
 452
 453                         read += input_event_size();
 454                 }
 455
 456                 if (read)
 457                         break;
 458
 459                 if (!(file->f_flags & O_NONBLOCK)) {
 460                         error = wait_event_interruptible(evdev->wait,
 461                                         client->packet_head != client->tail ||
 462                                         !evdev->exist);
 463                         if (error)
 464                                 return error;
 465                 }
 466         }
 467
 468         return read;
 469 }
 470
 471 /* No kernel lock - fine */
 472 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 473 {
 474         struct evdev_client *client = file->private_data;
 475         struct evdev *evdev = client->evdev;
 476         unsigned int mask;
 477
 478         poll_wait(file, &evdev->wait, wait);
 479
 480         mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
 481         if (client->packet_head != client->tail)
 482                 mask |= POLLIN | POLLRDNORM;
 483
 484         return mask;
 485 }
 486
 487 #ifdef CONFIG_COMPAT
 488
 489 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 490 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 491
 492 #ifdef __BIG_ENDIAN
 493 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 494                         unsigned int maxlen, void __user *p, int compat)
 495 {
 496         int len, i;
 497
 498         if (compat) {
 499                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 500                 if (len > maxlen)
 501                         len = maxlen;
 502
 503                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 504                         if (copy_to_user((compat_long_t __user *) p + i,
 505                                          (compat_long_t *) bits +
 506                                                 i + 1 - ((i % 2) << 1),
 507                                          sizeof(compat_long_t)))
 508                                 return -EFAULT;
 509         } else {
 510                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 511                 if (len > maxlen)
 512                         len = maxlen;
 513
 514                 if (copy_to_user(p, bits, len))
 515                         return -EFAULT;
 516         }
 517
 518         return len;
 519 }
 520 #else
 521 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 522                         unsigned int maxlen, void __user *p, int compat)
 523 {
 524         int len = compat ?
 525                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 526                         BITS_TO_LONGS(maxbit) * sizeof(long);
 527
 528         if (len > maxlen)
 529                 len = maxlen;
 530
 531         return copy_to_user(p, bits, len) ? -EFAULT : len;
 532 }
 533 #endif /* __BIG_ENDIAN */
 534
 535 #else
 536
 537 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 538                         unsigned int maxlen, void __user *p, int compat)
 539 {
 540         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 541
 542         if (len > maxlen)
 543                 len = maxlen;
 544
 545         return copy_to_user(p, bits, len) ? -EFAULT : len;
 546 }
 547
 548 #endif /* CONFIG_COMPAT */
 549
 550 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 551 {
 552         int len;
 553
 554         if (!str)
 555                 return -ENOENT;
 556
 557         len = strlen(str) + 1;
 558         if (len > maxlen)
 559                 len = maxlen;
 560
 561         return copy_to_user(p, str, len) ? -EFAULT : len;
 562 }
 563
 564 #define OLD_KEY_MAX     0x1ff
 565 static int handle_eviocgbit(struct input_dev *dev,
 566                             unsigned int type, unsigned int size,
 567                             void __user *p, int compat_mode)
 568 {
 569         static unsigned long keymax_warn_time;
 570         unsigned long *bits;
 571         int len;
 572
 573         switch (type) {
 574
 575         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 576         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 577         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 578         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 579         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 580         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 581         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 582         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 583         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 584         default: return -EINVAL;
 585         }
 586
 587         /*
 588          * Work around bugs in userspace programs that like to do
 589          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 590          * should be in bytes, not in bits.
 591          */
 592         if (type == EV_KEY && size == OLD_KEY_MAX) {
 593                 len = OLD_KEY_MAX;
 594                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 595                         pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
 596                                    "limiting output to %zu bytes. See "
 597                                    "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 598                                    OLD_KEY_MAX,
 599                                    BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 600         }
 601
 602         return bits_to_user(bits, len, size, p, compat_mode);
 603 }
 604 #undef OLD_KEY_MAX
 605
 606 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
 607 {
 608         struct input_keymap_entry ke = {
 609                 .len    = sizeof(unsigned int),
 610                 .flags  = 0,
 611         };
 612         int __user *ip = (int __user *)p;
 613         int error;
 614
 615         /* legacy case */
 616         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 617                 return -EFAULT;
 618
 619         error = input_get_keycode(dev, &ke);
 620         if (error)
 621                 return error;
 622
 623         if (put_user(ke.keycode, ip + 1))
 624                 return -EFAULT;
 625
 626         return 0;
 627 }
 628
 629 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
 630 {
 631         struct input_keymap_entry ke;
 632         int error;
 633
 634         if (copy_from_user(&ke, p, sizeof(ke)))
 635                 return -EFAULT;
 636
 637         error = input_get_keycode(dev, &ke);
 638         if (error)
 639                 return error;
 640
 641         if (copy_to_user(p, &ke, sizeof(ke)))
 642                 return -EFAULT;
 643
 644         return 0;
 645 }
 646
 647 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
 648 {
 649         struct input_keymap_entry ke = {
 650                 .len    = sizeof(unsigned int),
 651                 .flags  = 0,
 652         };
 653         int __user *ip = (int __user *)p;
 654
 655         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
 656                 return -EFAULT;
 657
 658         if (get_user(ke.keycode, ip + 1))
 659                 return -EFAULT;
 660
 661         return input_set_keycode(dev, &ke);
 662 }
 663
 664 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
 665 {
 666         struct input_keymap_entry ke;
 667
 668         if (copy_from_user(&ke, p, sizeof(ke)))
 669                 return -EFAULT;
 670
 671         if (ke.len > sizeof(ke.scancode))
 672                 return -EINVAL;
 673
 674         return input_set_keycode(dev, &ke);
 675 }
 676
 677 static int evdev_handle_mt_request(struct input_dev *dev,
 678                                    unsigned int size,
 679                                    int __user *ip)
 680 {
 681         const struct input_mt *mt = dev->mt;
 682         unsigned int code;
 683         int max_slots;
 684         int i;
 685
 686         if (get_user(code, &ip[0]))
 687                 return -EFAULT;
 688         if (!mt || !input_is_mt_value(code))
 689                 return -EINVAL;
 690
 691         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
 692         for (i = 0; i < mt->num_slots && i < max_slots; i++) {
 693                 int value = input_mt_get_value(&mt->slots[i], code);
 694                 if (put_user(value, &ip[1 + i]))
 695                         return -EFAULT;
 696         }
 697
 698         return 0;
 699 }
 700
 701 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 702                            void __user *p, int compat_mode)
 703 {
 704         struct evdev_client *client = file->private_data;
 705         struct evdev *evdev = client->evdev;
 706         struct input_dev *dev = evdev->handle.dev;
 707         struct input_absinfo abs;
 708         struct ff_effect effect;
 709         int __user *ip = (int __user *)p;
 710         unsigned int i, t, u, v;
 711         unsigned int size;
 712         int error;
 713
 714         /* First we check for fixed-length commands */
 715         switch (cmd) {
 716
 717         case EVIOCGVERSION:
 718                 return put_user(EV_VERSION, ip);
 719
 720         case EVIOCGID:
 721                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 722                         return -EFAULT;
 723                 return 0;
 724
 725         case EVIOCGREP:
 726                 if (!test_bit(EV_REP, dev->evbit))
 727                         return -ENOSYS;
 728                 if (put_user(dev->rep[REP_DELAY], ip))
 729                         return -EFAULT;
 730                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 731                         return -EFAULT;
 732                 return 0;
 733
 734         case EVIOCSREP:
 735                 if (!test_bit(EV_REP, dev->evbit))
 736                         return -ENOSYS;
 737                 if (get_user(u, ip))
 738                         return -EFAULT;
 739                 if (get_user(v, ip + 1))
 740                         return -EFAULT;
 741
 742                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 743                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 744
 745                 return 0;
 746
 747         case EVIOCRMFF:
 748                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 749
 750         case EVIOCGEFFECTS:
 751                 i = test_bit(EV_FF, dev->evbit) ?
 752                                 dev->ff->max_effects : 0;
 753                 if (put_user(i, ip))
 754                         return -EFAULT;
 755                 return 0;
 756
 757         case EVIOCGRAB:
 758                 if (p)
 759                         return evdev_grab(evdev, client);
 760                 else
 761                         return evdev_ungrab(evdev, client);
 762
 763         case EVIOCSCLOCKID:
 764                 if (copy_from_user(&i, p, sizeof(unsigned int)))
 765                         return -EFAULT;
 766                 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
 767                         return -EINVAL;
 768                 client->clkid = i;
 769                 return 0;
 770
 771         case EVIOCGKEYCODE:
 772                 return evdev_handle_get_keycode(dev, p);
 773
 774         case EVIOCSKEYCODE:
 775                 return evdev_handle_set_keycode(dev, p);
 776
 777         case EVIOCGKEYCODE_V2:
 778                 return evdev_handle_get_keycode_v2(dev, p);
 779
 780         case EVIOCSKEYCODE_V2:
 781                 return evdev_handle_set_keycode_v2(dev, p);
 782         }
 783
 784         size = _IOC_SIZE(cmd);
 785
 786         /* Now check variable-length commands */
 787 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
 788         switch (EVIOC_MASK_SIZE(cmd)) {
 789
 790         case EVIOCGPROP(0):
 791                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
 792                                     size, p, compat_mode);
 793
 794         case EVIOCGMTSLOTS(0):
 795                 return evdev_handle_mt_request(dev, size, ip);
 796
 797         case EVIOCGKEY(0):
 798                 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
 799
 800         case EVIOCGLED(0):
 801                 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
 802
 803         case EVIOCGSND(0):
 804                 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
 805
 806         case EVIOCGSW(0):
 807                 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
 808
 809         case EVIOCGNAME(0):
 810                 return str_to_user(dev->name, size, p);
 811
 812         case EVIOCGPHYS(0):
 813                 return str_to_user(dev->phys, size, p);
 814
 815         case EVIOCGUNIQ(0):
 816                 return str_to_user(dev->uniq, size, p);
 817
 818         case EVIOC_MASK_SIZE(EVIOCSFF):
 819                 if (input_ff_effect_from_user(p, size, &effect))
 820                         return -EFAULT;
 821
 822                 error = input_ff_upload(dev, &effect, file);
 823
 824                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 825                         return -EFAULT;
 826
 827                 return error;
 828         }
 829
 830         /* Multi-number variable-length handlers */
 831         if (_IOC_TYPE(cmd) != 'E')
 832                 return -EINVAL;
 833
 834         if (_IOC_DIR(cmd) == _IOC_READ) {
 835
 836                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 837                         return handle_eviocgbit(dev,
 838                                                 _IOC_NR(cmd) & EV_MAX, size,
 839                                                 p, compat_mode);
 840
 841                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 842
 843                         if (!dev->absinfo)
 844                                 return -EINVAL;
 845
 846                         t = _IOC_NR(cmd) & ABS_MAX;
 847                         abs = dev->absinfo[t];
 848
 849                         if (copy_to_user(p, &abs, min_t(size_t,
 850                                         size, sizeof(struct input_absinfo))))
 851                                 return -EFAULT;
 852
 853                         return 0;
 854                 }
 855         }
 856
 857         if (_IOC_DIR(cmd) == _IOC_WRITE) {
 858
 859                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 860
 861                         if (!dev->absinfo)
 862                                 return -EINVAL;
 863
 864                         t = _IOC_NR(cmd) & ABS_MAX;
 865
 866                         if (copy_from_user(&abs, p, min_t(size_t,
 867                                         size, sizeof(struct input_absinfo))))
 868                                 return -EFAULT;
 869
 870                         if (size < sizeof(struct input_absinfo))
 871                                 abs.resolution = 0;
 872
 873                         /* We can't change number of reserved MT slots */
 874                         if (t == ABS_MT_SLOT)
 875                                 return -EINVAL;
 876
 877                         /*
 878                          * Take event lock to ensure that we are not
 879                          * changing device parameters in the middle
 880                          * of event.
 881                          */
 882                         spin_lock_irq(&dev->event_lock);
 883                         dev->absinfo[t] = abs;
 884                         spin_unlock_irq(&dev->event_lock);
 885
 886                         return 0;
 887                 }
 888         }
 889
 890         return -EINVAL;
 891 }
 892
 893 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 894                                 void __user *p, int compat_mode)
 895 {
 896         struct evdev_client *client = file->private_data;
 897         struct evdev *evdev = client->evdev;
 898         int retval;
 899
 900         retval = mutex_lock_interruptible(&evdev->mutex);
 901         if (retval)
 902                 return retval;
 903
 904         if (!evdev->exist) {
 905                 retval = -ENODEV;
 906                 goto out;
 907         }
 908
 909         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 910
 911  out:
 912         mutex_unlock(&evdev->mutex);
 913         return retval;
 914 }
 915
 916 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 917 {
 918         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 919 }
 920
 921 #ifdef CONFIG_COMPAT
 922 static long evdev_ioctl_compat(struct file *file,
 923                                 unsigned int cmd, unsigned long arg)
 924 {
 925         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 926 }
 927 #endif
 928
 929 static const struct file_operations evdev_fops = {
 930         .owner          = THIS_MODULE,
 931         .read           = evdev_read,
 932         .write          = evdev_write,
 933         .poll           = evdev_poll,
 934         .open           = evdev_open,
 935         .release        = evdev_release,
 936         .unlocked_ioctl = evdev_ioctl,
 937 #ifdef CONFIG_COMPAT
 938         .compat_ioctl   = evdev_ioctl_compat,
 939 #endif
 940         .fasync         = evdev_fasync,
 941         .flush          = evdev_flush,
 942         .llseek         = no_llseek,
 943 };
 944
 945 static int evdev_install_chrdev(struct evdev *evdev)
 946 {
 947         /*
 948          * No need to do any locking here as calls to connect and
 949          * disconnect are serialized by the input core
 950          */
 951         evdev_table[evdev->minor] = evdev;
 952         return 0;
 953 }
 954
 955 static void evdev_remove_chrdev(struct evdev *evdev)
 956 {
 957         /*
 958          * Lock evdev table to prevent race with evdev_open()
 959          */
 960         mutex_lock(&evdev_table_mutex);
 961         evdev_table[evdev->minor] = NULL;
 962         mutex_unlock(&evdev_table_mutex);
 963 }
 964
 965 /*
 966  * Mark device non-existent. This disables writes, ioctls and
 967  * prevents new users from opening the device. Already posted
 968  * blocking reads will stay, however new ones will fail.
 969  */
 970 static void evdev_mark_dead(struct evdev *evdev)
 971 {
 972         mutex_lock(&evdev->mutex);
 973         evdev->exist = false;
 974         mutex_unlock(&evdev->mutex);
 975 }
 976
 977 static void evdev_cleanup(struct evdev *evdev)
 978 {
 979         struct input_handle *handle = &evdev->handle;
 980
 981         evdev_mark_dead(evdev);
 982         evdev_hangup(evdev);
 983         evdev_remove_chrdev(evdev);
 984
 985         /* evdev is marked dead so no one else accesses evdev->open */
 986         if (evdev->open) {
 987                 input_flush_device(handle, NULL);
 988                 input_close_device(handle);
 989         }
 990 }
 991
 992 /*
 993  * Create new evdev device. Note that input core serializes calls
 994  * to connect and disconnect so we don't need to lock evdev_table here.
 995  */
 996 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 997                          const struct input_device_id *id)
 998 {
 999         struct evdev *evdev;
1000         int minor;
1001         int error;
1002
1003         for (minor = 0; minor < EVDEV_MINORS; minor++)
1004                 if (!evdev_table[minor])
1005                         break;
1006
1007         if (minor == EVDEV_MINORS) {
1008                 pr_err("no more free evdev devices\n");
1009                 return -ENFILE;
1010         }
1011
1012         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1013         if (!evdev)
1014                 return -ENOMEM;
1015
1016         INIT_LIST_HEAD(&evdev->client_list);
1017         spin_lock_init(&evdev->client_lock);
1018         mutex_init(&evdev->mutex);
1019         init_waitqueue_head(&evdev->wait);
1020
1021         dev_set_name(&evdev->dev, "event%d", minor);
1022         evdev->exist = true;
1023         evdev->minor = minor;
1024
1025         evdev->handle.dev = input_get_device(dev);
1026         evdev->handle.name = dev_name(&evdev->dev);
1027         evdev->handle.handler = handler;
1028         evdev->handle.private = evdev;
1029
1030         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
1031         evdev->dev.class = &input_class;
1032         evdev->dev.parent = &dev->dev;
1033         evdev->dev.release = evdev_free;
1034         device_initialize(&evdev->dev);
1035
1036         error = input_register_handle(&evdev->handle);
1037         if (error)
1038                 goto err_free_evdev;
1039
1040         error = evdev_install_chrdev(evdev);
1041         if (error)
1042                 goto err_unregister_handle;
1043
1044         error = device_add(&evdev->dev);
1045         if (error)
1046                 goto err_cleanup_evdev;
1047
1048         return 0;
1049
1050  err_cleanup_evdev:
1051         evdev_cleanup(evdev);
1052  err_unregister_handle:
1053         input_unregister_handle(&evdev->handle);
1054  err_free_evdev:
1055         put_device(&evdev->dev);
1056         return error;
1057 }
1058
1059 static void evdev_disconnect(struct input_handle *handle)
1060 {
1061         struct evdev *evdev = handle->private;
1062
1063         device_del(&evdev->dev);
1064         evdev_cleanup(evdev);
1065         input_unregister_handle(handle);
1066         put_device(&evdev->dev);
1067 }
1068
1069 static const struct input_device_id evdev_ids[] = {
1070         { .driver_info = 1 },   /* Matches all devices */
1071         { },                    /* Terminating zero entry */
1072 };
1073
1074 MODULE_DEVICE_TABLE(input, evdev_ids);
1075
1076 static struct input_handler evdev_handler = {
1077         .event          = evdev_event,
1078         .events         = evdev_events,
1079         .connect        = evdev_connect,
1080         .disconnect     = evdev_disconnect,
1081         .fops           = &evdev_fops,
1082         .minor          = EVDEV_MINOR_BASE,
1083         .name           = "evdev",
1084         .id_table       = evdev_ids,
1085 };
1086
1087 static int __init evdev_init(void)
1088 {
1089         return input_register_handler(&evdev_handler);
1090 }
1091
1092 static void __exit evdev_exit(void)
1093 {
1094         input_unregister_handler(&evdev_handler);
1095 }
1096
1097 module_init(evdev_init);
1098 module_exit(evdev_exit);
1099
1100 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1101 MODULE_DESCRIPTION("Input driver event char devices");
1102 MODULE_LICENSE("GPL");