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 EVDEV_MINOR_BASE        64
  12 #define EVDEV_MINORS            32
  13 #define EVDEV_BUFFER_SIZE       64
  14
  15 #include <linux/poll.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/input.h>
  20 #include <linux/major.h>
  21 #include <linux/device.h>
  22 #include <linux/compat.h>
  23
  24 struct evdev {
  25         int exist;
  26         int open;
  27         int minor;
  28         char name[16];
  29         struct input_handle handle;
  30         wait_queue_head_t wait;
  31         struct evdev_client *grab;
  32         struct list_head client_list;
  33         spinlock_t client_lock; /* protects client_list */
  34         struct mutex mutex;
  35         struct device dev;
  36 };
  37
  38 struct evdev_client {
  39         struct input_event buffer[EVDEV_BUFFER_SIZE];
  40         int head;
  41         int tail;
  42         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  43         struct fasync_struct *fasync;
  44         struct evdev *evdev;
  45         struct list_head node;
  46 };
  47
  48 static struct evdev *evdev_table[EVDEV_MINORS];
  49 static DEFINE_MUTEX(evdev_table_mutex);
  50
  51 static void evdev_pass_event(struct evdev_client *client,
  52                              struct input_event *event)
  53 {
  54         /*
  55          * Interrupts are disabled, just acquire the lock
  56          */
  57         spin_lock(&client->buffer_lock);
  58         client->buffer[client->head++] = *event;
  59         client->head &= EVDEV_BUFFER_SIZE - 1;
  60         spin_unlock(&client->buffer_lock);
  61
  62         kill_fasync(&client->fasync, SIGIO, POLL_IN);
  63 }
  64
  65 /*
  66  * Pass incoming event to all connected clients.
  67  */
  68 static void evdev_event(struct input_handle *handle,
  69                         unsigned int type, unsigned int code, int value)
  70 {
  71         struct evdev *evdev = handle->private;
  72         struct evdev_client *client;
  73         struct input_event event;
  74
  75         do_gettimeofday(&event.time);
  76         event.type = type;
  77         event.code = code;
  78         event.value = value;
  79
  80         rcu_read_lock();
  81
  82         client = rcu_dereference(evdev->grab);
  83         if (client)
  84                 evdev_pass_event(client, &event);
  85         else
  86                 list_for_each_entry_rcu(client, &evdev->client_list, node)
  87                         evdev_pass_event(client, &event);
  88
  89         rcu_read_unlock();
  90
  91         wake_up_interruptible(&evdev->wait);
  92 }
  93
  94 static int evdev_fasync(int fd, struct file *file, int on)
  95 {
  96         struct evdev_client *client = file->private_data;
  97         int retval;
  98
  99         retval = fasync_helper(fd, file, on, &client->fasync);
 100
 101         return retval < 0 ? retval : 0;
 102 }
 103
 104 static int evdev_flush(struct file *file, fl_owner_t id)
 105 {
 106         struct evdev_client *client = file->private_data;
 107         struct evdev *evdev = client->evdev;
 108         int retval;
 109
 110         retval = mutex_lock_interruptible(&evdev->mutex);
 111         if (retval)
 112                 return retval;
 113
 114         if (!evdev->exist)
 115                 retval = -ENODEV;
 116         else
 117                 retval = input_flush_device(&evdev->handle, file);
 118
 119         mutex_unlock(&evdev->mutex);
 120         return retval;
 121 }
 122
 123 static void evdev_free(struct device *dev)
 124 {
 125         struct evdev *evdev = container_of(dev, struct evdev, dev);
 126
 127         input_put_device(evdev->handle.dev);
 128         kfree(evdev);
 129 }
 130
 131 /*
 132  * Grabs an event device (along with underlying input device).
 133  * This function is called with evdev->mutex taken.
 134  */
 135 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
 136 {
 137         int error;
 138
 139         if (evdev->grab)
 140                 return -EBUSY;
 141
 142         error = input_grab_device(&evdev->handle);
 143         if (error)
 144                 return error;
 145
 146         rcu_assign_pointer(evdev->grab, client);
 147         synchronize_rcu();
 148
 149         return 0;
 150 }
 151
 152 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
 153 {
 154         if (evdev->grab != client)
 155                 return  -EINVAL;
 156
 157         rcu_assign_pointer(evdev->grab, NULL);
 158         synchronize_rcu();
 159         input_release_device(&evdev->handle);
 160
 161         return 0;
 162 }
 163
 164 static void evdev_attach_client(struct evdev *evdev,
 165                                 struct evdev_client *client)
 166 {
 167         spin_lock(&evdev->client_lock);
 168         list_add_tail_rcu(&client->node, &evdev->client_list);
 169         spin_unlock(&evdev->client_lock);
 170         synchronize_rcu();
 171 }
 172
 173 static void evdev_detach_client(struct evdev *evdev,
 174                                 struct evdev_client *client)
 175 {
 176         spin_lock(&evdev->client_lock);
 177         list_del_rcu(&client->node);
 178         spin_unlock(&evdev->client_lock);
 179         synchronize_rcu();
 180 }
 181
 182 static int evdev_open_device(struct evdev *evdev)
 183 {
 184         int retval;
 185
 186         retval = mutex_lock_interruptible(&evdev->mutex);
 187         if (retval)
 188                 return retval;
 189
 190         if (!evdev->exist)
 191                 retval = -ENODEV;
 192         else if (!evdev->open++) {
 193                 retval = input_open_device(&evdev->handle);
 194                 if (retval)
 195                         evdev->open--;
 196         }
 197
 198         mutex_unlock(&evdev->mutex);
 199         return retval;
 200 }
 201
 202 static void evdev_close_device(struct evdev *evdev)
 203 {
 204         mutex_lock(&evdev->mutex);
 205
 206         if (evdev->exist && !--evdev->open)
 207                 input_close_device(&evdev->handle);
 208
 209         mutex_unlock(&evdev->mutex);
 210 }
 211
 212 /*
 213  * Wake up users waiting for IO so they can disconnect from
 214  * dead device.
 215  */
 216 static void evdev_hangup(struct evdev *evdev)
 217 {
 218         struct evdev_client *client;
 219
 220         spin_lock(&evdev->client_lock);
 221         list_for_each_entry(client, &evdev->client_list, node)
 222                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 223         spin_unlock(&evdev->client_lock);
 224
 225         wake_up_interruptible(&evdev->wait);
 226 }
 227
 228 static int evdev_release(struct inode *inode, struct file *file)
 229 {
 230         struct evdev_client *client = file->private_data;
 231         struct evdev *evdev = client->evdev;
 232
 233         mutex_lock(&evdev->mutex);
 234         if (evdev->grab == client)
 235                 evdev_ungrab(evdev, client);
 236         mutex_unlock(&evdev->mutex);
 237
 238         evdev_fasync(-1, file, 0);
 239         evdev_detach_client(evdev, client);
 240         kfree(client);
 241
 242         evdev_close_device(evdev);
 243         put_device(&evdev->dev);
 244
 245         return 0;
 246 }
 247
 248 static int evdev_open(struct inode *inode, struct file *file)
 249 {
 250         struct evdev *evdev;
 251         struct evdev_client *client;
 252         int i = iminor(inode) - EVDEV_MINOR_BASE;
 253         int error;
 254
 255         if (i >= EVDEV_MINORS)
 256                 return -ENODEV;
 257
 258         error = mutex_lock_interruptible(&evdev_table_mutex);
 259         if (error)
 260                 return error;
 261         evdev = evdev_table[i];
 262         if (evdev)
 263                 get_device(&evdev->dev);
 264         mutex_unlock(&evdev_table_mutex);
 265
 266         if (!evdev)
 267                 return -ENODEV;
 268
 269         client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
 270         if (!client) {
 271                 error = -ENOMEM;
 272                 goto err_put_evdev;
 273         }
 274
 275         spin_lock_init(&client->buffer_lock);
 276         client->evdev = evdev;
 277         evdev_attach_client(evdev, client);
 278
 279         error = evdev_open_device(evdev);
 280         if (error)
 281                 goto err_free_client;
 282
 283         file->private_data = client;
 284         return 0;
 285
 286  err_free_client:
 287         evdev_detach_client(evdev, client);
 288         kfree(client);
 289  err_put_evdev:
 290         put_device(&evdev->dev);
 291         return error;
 292 }
 293
 294 #ifdef CONFIG_COMPAT
 295
 296 struct input_event_compat {
 297         struct compat_timeval time;
 298         __u16 type;
 299         __u16 code;
 300         __s32 value;
 301 };
 302
 303 struct ff_periodic_effect_compat {
 304         __u16 waveform;
 305         __u16 period;
 306         __s16 magnitude;
 307         __s16 offset;
 308         __u16 phase;
 309
 310         struct ff_envelope envelope;
 311
 312         __u32 custom_len;
 313         compat_uptr_t custom_data;
 314 };
 315
 316 struct ff_effect_compat {
 317         __u16 type;
 318         __s16 id;
 319         __u16 direction;
 320         struct ff_trigger trigger;
 321         struct ff_replay replay;
 322
 323         union {
 324                 struct ff_constant_effect constant;
 325                 struct ff_ramp_effect ramp;
 326                 struct ff_periodic_effect_compat periodic;
 327                 struct ff_condition_effect condition[2]; /* One for each axis */
 328                 struct ff_rumble_effect rumble;
 329         } u;
 330 };
 331
 332 /* Note to the author of this code: did it ever occur to
 333    you why the ifdefs are needed? Think about it again. -AK */
 334 #ifdef CONFIG_X86_64
 335 #  define COMPAT_TEST is_compat_task()
 336 #elif defined(CONFIG_IA64)
 337 #  define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current))
 338 #elif defined(CONFIG_S390)
 339 #  define COMPAT_TEST test_thread_flag(TIF_31BIT)
 340 #elif defined(CONFIG_MIPS)
 341 #  define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
 342 #else
 343 #  define COMPAT_TEST test_thread_flag(TIF_32BIT)
 344 #endif
 345
 346 static inline size_t evdev_event_size(void)
 347 {
 348         return COMPAT_TEST ?
 349                 sizeof(struct input_event_compat) : sizeof(struct input_event);
 350 }
 351
 352 static int evdev_event_from_user(const char __user *buffer,
 353                                  struct input_event *event)
 354 {
 355         if (COMPAT_TEST) {
 356                 struct input_event_compat compat_event;
 357
 358                 if (copy_from_user(&compat_event, buffer,
 359                                    sizeof(struct input_event_compat)))
 360                         return -EFAULT;
 361
 362                 event->time.tv_sec = compat_event.time.tv_sec;
 363                 event->time.tv_usec = compat_event.time.tv_usec;
 364                 event->type = compat_event.type;
 365                 event->code = compat_event.code;
 366                 event->value = compat_event.value;
 367
 368         } else {
 369                 if (copy_from_user(event, buffer, sizeof(struct input_event)))
 370                         return -EFAULT;
 371         }
 372
 373         return 0;
 374 }
 375
 376 static int evdev_event_to_user(char __user *buffer,
 377                                 const struct input_event *event)
 378 {
 379         if (COMPAT_TEST) {
 380                 struct input_event_compat compat_event;
 381
 382                 compat_event.time.tv_sec = event->time.tv_sec;
 383                 compat_event.time.tv_usec = event->time.tv_usec;
 384                 compat_event.type = event->type;
 385                 compat_event.code = event->code;
 386                 compat_event.value = event->value;
 387
 388                 if (copy_to_user(buffer, &compat_event,
 389                                  sizeof(struct input_event_compat)))
 390                         return -EFAULT;
 391
 392         } else {
 393                 if (copy_to_user(buffer, event, sizeof(struct input_event)))
 394                         return -EFAULT;
 395         }
 396
 397         return 0;
 398 }
 399
 400 static int evdev_ff_effect_from_user(const char __user *buffer, size_t size,
 401                                      struct ff_effect *effect)
 402 {
 403         if (COMPAT_TEST) {
 404                 struct ff_effect_compat *compat_effect;
 405
 406                 if (size != sizeof(struct ff_effect_compat))
 407                         return -EINVAL;
 408
 409                 /*
 410                  * It so happens that the pointer which needs to be changed
 411                  * is the last field in the structure, so we can copy the
 412                  * whole thing and replace just the pointer.
 413                  */
 414
 415                 compat_effect = (struct ff_effect_compat *)effect;
 416
 417                 if (copy_from_user(compat_effect, buffer,
 418                                    sizeof(struct ff_effect_compat)))
 419                         return -EFAULT;
 420
 421                 if (compat_effect->type == FF_PERIODIC &&
 422                     compat_effect->u.periodic.waveform == FF_CUSTOM)
 423                         effect->u.periodic.custom_data =
 424                                 compat_ptr(compat_effect->u.periodic.custom_data);
 425         } else {
 426                 if (size != sizeof(struct ff_effect))
 427                         return -EINVAL;
 428
 429                 if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
 430                         return -EFAULT;
 431         }
 432
 433         return 0;
 434 }
 435
 436 #else
 437
 438 static inline size_t evdev_event_size(void)
 439 {
 440         return sizeof(struct input_event);
 441 }
 442
 443 static int evdev_event_from_user(const char __user *buffer,
 444                                  struct input_event *event)
 445 {
 446         if (copy_from_user(event, buffer, sizeof(struct input_event)))
 447                 return -EFAULT;
 448
 449         return 0;
 450 }
 451
 452 static int evdev_event_to_user(char __user *buffer,
 453                                 const struct input_event *event)
 454 {
 455         if (copy_to_user(buffer, event, sizeof(struct input_event)))
 456                 return -EFAULT;
 457
 458         return 0;
 459 }
 460
 461 static int evdev_ff_effect_from_user(const char __user *buffer, size_t size,
 462                                      struct ff_effect *effect)
 463 {
 464         if (size != sizeof(struct ff_effect))
 465                 return -EINVAL;
 466
 467         if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
 468                 return -EFAULT;
 469
 470         return 0;
 471 }
 472
 473 #endif /* CONFIG_COMPAT */
 474
 475 static ssize_t evdev_write(struct file *file, const char __user *buffer,
 476                            size_t count, loff_t *ppos)
 477 {
 478         struct evdev_client *client = file->private_data;
 479         struct evdev *evdev = client->evdev;
 480         struct input_event event;
 481         int retval;
 482
 483         retval = mutex_lock_interruptible(&evdev->mutex);
 484         if (retval)
 485                 return retval;
 486
 487         if (!evdev->exist) {
 488                 retval = -ENODEV;
 489                 goto out;
 490         }
 491
 492         while (retval < count) {
 493
 494                 if (evdev_event_from_user(buffer + retval, &event)) {
 495                         retval = -EFAULT;
 496                         goto out;
 497                 }
 498
 499                 input_inject_event(&evdev->handle,
 500                                    event.type, event.code, event.value);
 501                 retval += evdev_event_size();
 502         }
 503
 504  out:
 505         mutex_unlock(&evdev->mutex);
 506         return retval;
 507 }
 508
 509 static int evdev_fetch_next_event(struct evdev_client *client,
 510                                   struct input_event *event)
 511 {
 512         int have_event;
 513
 514         spin_lock_irq(&client->buffer_lock);
 515
 516         have_event = client->head != client->tail;
 517         if (have_event) {
 518                 *event = client->buffer[client->tail++];
 519                 client->tail &= EVDEV_BUFFER_SIZE - 1;
 520         }
 521
 522         spin_unlock_irq(&client->buffer_lock);
 523
 524         return have_event;
 525 }
 526
 527 static ssize_t evdev_read(struct file *file, char __user *buffer,
 528                           size_t count, loff_t *ppos)
 529 {
 530         struct evdev_client *client = file->private_data;
 531         struct evdev *evdev = client->evdev;
 532         struct input_event event;
 533         int retval;
 534
 535         if (count < evdev_event_size())
 536                 return -EINVAL;
 537
 538         if (client->head == client->tail && evdev->exist &&
 539             (file->f_flags & O_NONBLOCK))
 540                 return -EAGAIN;
 541
 542         retval = wait_event_interruptible(evdev->wait,
 543                 client->head != client->tail || !evdev->exist);
 544         if (retval)
 545                 return retval;
 546
 547         if (!evdev->exist)
 548                 return -ENODEV;
 549
 550         while (retval + evdev_event_size() <= count &&
 551                evdev_fetch_next_event(client, &event)) {
 552
 553                 if (evdev_event_to_user(buffer + retval, &event))
 554                         return -EFAULT;
 555
 556                 retval += evdev_event_size();
 557         }
 558
 559         return retval;
 560 }
 561
 562 /* No kernel lock - fine */
 563 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 564 {
 565         struct evdev_client *client = file->private_data;
 566         struct evdev *evdev = client->evdev;
 567
 568         poll_wait(file, &evdev->wait, wait);
 569         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 570                 (evdev->exist ? 0 : (POLLHUP | POLLERR));
 571 }
 572
 573 #ifdef CONFIG_COMPAT
 574
 575 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
 576 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
 577
 578 #ifdef __BIG_ENDIAN
 579 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 580                         unsigned int maxlen, void __user *p, int compat)
 581 {
 582         int len, i;
 583
 584         if (compat) {
 585                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
 586                 if (len > maxlen)
 587                         len = maxlen;
 588
 589                 for (i = 0; i < len / sizeof(compat_long_t); i++)
 590                         if (copy_to_user((compat_long_t __user *) p + i,
 591                                          (compat_long_t *) bits +
 592                                                 i + 1 - ((i % 2) << 1),
 593                                          sizeof(compat_long_t)))
 594                                 return -EFAULT;
 595         } else {
 596                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
 597                 if (len > maxlen)
 598                         len = maxlen;
 599
 600                 if (copy_to_user(p, bits, len))
 601                         return -EFAULT;
 602         }
 603
 604         return len;
 605 }
 606 #else
 607 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 608                         unsigned int maxlen, void __user *p, int compat)
 609 {
 610         int len = compat ?
 611                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
 612                         BITS_TO_LONGS(maxbit) * sizeof(long);
 613
 614         if (len > maxlen)
 615                 len = maxlen;
 616
 617         return copy_to_user(p, bits, len) ? -EFAULT : len;
 618 }
 619 #endif /* __BIG_ENDIAN */
 620
 621 #else
 622
 623 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
 624                         unsigned int maxlen, void __user *p, int compat)
 625 {
 626         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
 627
 628         if (len > maxlen)
 629                 len = maxlen;
 630
 631         return copy_to_user(p, bits, len) ? -EFAULT : len;
 632 }
 633
 634 #endif /* CONFIG_COMPAT */
 635
 636 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 637 {
 638         int len;
 639
 640         if (!str)
 641                 return -ENOENT;
 642
 643         len = strlen(str) + 1;
 644         if (len > maxlen)
 645                 len = maxlen;
 646
 647         return copy_to_user(p, str, len) ? -EFAULT : len;
 648 }
 649
 650 #define OLD_KEY_MAX     0x1ff
 651 static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
 652 {
 653         static unsigned long keymax_warn_time;
 654         unsigned long *bits;
 655         int len;
 656
 657         switch (_IOC_NR(cmd) & EV_MAX) {
 658
 659         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 660         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 661         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 662         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 663         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
 664         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 665         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 666         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
 667         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
 668         default: return -EINVAL;
 669         }
 670
 671         /*
 672          * Work around bugs in userspace programs that like to do
 673          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
 674          * should be in bytes, not in bits.
 675          */
 676         if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
 677                 len = OLD_KEY_MAX;
 678                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
 679                         printk(KERN_WARNING
 680                                 "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
 681                                 "limiting output to %zu bytes. See "
 682                                 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
 683                                 OLD_KEY_MAX,
 684                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
 685         }
 686
 687         return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
 688 }
 689 #undef OLD_KEY_MAX
 690
 691 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
 692                            void __user *p, int compat_mode)
 693 {
 694         struct evdev_client *client = file->private_data;
 695         struct evdev *evdev = client->evdev;
 696         struct input_dev *dev = evdev->handle.dev;
 697         struct input_absinfo abs;
 698         struct ff_effect effect;
 699         int __user *ip = (int __user *)p;
 700         int i, t, u, v;
 701         int error;
 702
 703         switch (cmd) {
 704
 705         case EVIOCGVERSION:
 706                 return put_user(EV_VERSION, ip);
 707
 708         case EVIOCGID:
 709                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
 710                         return -EFAULT;
 711                 return 0;
 712
 713         case EVIOCGREP:
 714                 if (!test_bit(EV_REP, dev->evbit))
 715                         return -ENOSYS;
 716                 if (put_user(dev->rep[REP_DELAY], ip))
 717                         return -EFAULT;
 718                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
 719                         return -EFAULT;
 720                 return 0;
 721
 722         case EVIOCSREP:
 723                 if (!test_bit(EV_REP, dev->evbit))
 724                         return -ENOSYS;
 725                 if (get_user(u, ip))
 726                         return -EFAULT;
 727                 if (get_user(v, ip + 1))
 728                         return -EFAULT;
 729
 730                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
 731                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
 732
 733                 return 0;
 734
 735         case EVIOCGKEYCODE:
 736                 if (get_user(t, ip))
 737                         return -EFAULT;
 738
 739                 error = input_get_keycode(dev, t, &v);
 740                 if (error)
 741                         return error;
 742
 743                 if (put_user(v, ip + 1))
 744                         return -EFAULT;
 745
 746                 return 0;
 747
 748         case EVIOCSKEYCODE:
 749                 if (get_user(t, ip) || get_user(v, ip + 1))
 750                         return -EFAULT;
 751
 752                 return input_set_keycode(dev, t, v);
 753
 754         case EVIOCRMFF:
 755                 return input_ff_erase(dev, (int)(unsigned long) p, file);
 756
 757         case EVIOCGEFFECTS:
 758                 i = test_bit(EV_FF, dev->evbit) ?
 759                                 dev->ff->max_effects : 0;
 760                 if (put_user(i, ip))
 761                         return -EFAULT;
 762                 return 0;
 763
 764         case EVIOCGRAB:
 765                 if (p)
 766                         return evdev_grab(evdev, client);
 767                 else
 768                         return evdev_ungrab(evdev, client);
 769
 770         default:
 771
 772                 if (_IOC_TYPE(cmd) != 'E')
 773                         return -EINVAL;
 774
 775                 if (_IOC_DIR(cmd) == _IOC_READ) {
 776
 777                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
 778                                 return handle_eviocgbit(dev, cmd, p, compat_mode);
 779
 780                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
 781                                 return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
 782                                                     p, compat_mode);
 783
 784                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
 785                                 return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
 786                                                     p, compat_mode);
 787
 788                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
 789                                 return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
 790                                                     p, compat_mode);
 791
 792                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
 793                                 return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
 794                                                     p, compat_mode);
 795
 796                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
 797                                 return str_to_user(dev->name, _IOC_SIZE(cmd), p);
 798
 799                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
 800                                 return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
 801
 802                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
 803                                 return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
 804
 805                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 806
 807                                 t = _IOC_NR(cmd) & ABS_MAX;
 808
 809                                 abs.value = dev->abs[t];
 810                                 abs.minimum = dev->absmin[t];
 811                                 abs.maximum = dev->absmax[t];
 812                                 abs.fuzz = dev->absfuzz[t];
 813                                 abs.flat = dev->absflat[t];
 814
 815                                 if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
 816                                         return -EFAULT;
 817
 818                                 return 0;
 819                         }
 820
 821                 }
 822
 823                 if (_IOC_DIR(cmd) == _IOC_WRITE) {
 824
 825                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCSFF)) {
 826
 827                                 if (evdev_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
 828                                         return -EFAULT;
 829
 830                                 error = input_ff_upload(dev, &effect, file);
 831
 832                                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
 833                                         return -EFAULT;
 834
 835                                 return error;
 836                         }
 837
 838                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
 839
 840                                 t = _IOC_NR(cmd) & ABS_MAX;
 841
 842                                 if (copy_from_user(&abs, p,
 843                                                 sizeof(struct input_absinfo)))
 844                                         return -EFAULT;
 845
 846                                 /*
 847                                  * Take event lock to ensure that we are not
 848                                  * changing device parameters in the middle
 849                                  * of event.
 850                                  */
 851                                 spin_lock_irq(&dev->event_lock);
 852
 853                                 dev->abs[t] = abs.value;
 854                                 dev->absmin[t] = abs.minimum;
 855                                 dev->absmax[t] = abs.maximum;
 856                                 dev->absfuzz[t] = abs.fuzz;
 857                                 dev->absflat[t] = abs.flat;
 858
 859                                 spin_unlock_irq(&dev->event_lock);
 860
 861                                 return 0;
 862                         }
 863                 }
 864         }
 865         return -EINVAL;
 866 }
 867
 868 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
 869                                 void __user *p, int compat_mode)
 870 {
 871         struct evdev_client *client = file->private_data;
 872         struct evdev *evdev = client->evdev;
 873         int retval;
 874
 875         retval = mutex_lock_interruptible(&evdev->mutex);
 876         if (retval)
 877                 return retval;
 878
 879         if (!evdev->exist) {
 880                 retval = -ENODEV;
 881                 goto out;
 882         }
 883
 884         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
 885
 886  out:
 887         mutex_unlock(&evdev->mutex);
 888         return retval;
 889 }
 890
 891 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 892 {
 893         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
 894 }
 895
 896 #ifdef CONFIG_COMPAT
 897 static long evdev_ioctl_compat(struct file *file,
 898                                 unsigned int cmd, unsigned long arg)
 899 {
 900         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
 901 }
 902 #endif
 903
 904 static const struct file_operations evdev_fops = {
 905         .owner          = THIS_MODULE,
 906         .read           = evdev_read,
 907         .write          = evdev_write,
 908         .poll           = evdev_poll,
 909         .open           = evdev_open,
 910         .release        = evdev_release,
 911         .unlocked_ioctl = evdev_ioctl,
 912 #ifdef CONFIG_COMPAT
 913         .compat_ioctl   = evdev_ioctl_compat,
 914 #endif
 915         .fasync         = evdev_fasync,
 916         .flush          = evdev_flush
 917 };
 918
 919 static int evdev_install_chrdev(struct evdev *evdev)
 920 {
 921         /*
 922          * No need to do any locking here as calls to connect and
 923          * disconnect are serialized by the input core
 924          */
 925         evdev_table[evdev->minor] = evdev;
 926         return 0;
 927 }
 928
 929 static void evdev_remove_chrdev(struct evdev *evdev)
 930 {
 931         /*
 932          * Lock evdev table to prevent race with evdev_open()
 933          */
 934         mutex_lock(&evdev_table_mutex);
 935         evdev_table[evdev->minor] = NULL;
 936         mutex_unlock(&evdev_table_mutex);
 937 }
 938
 939 /*
 940  * Mark device non-existent. This disables writes, ioctls and
 941  * prevents new users from opening the device. Already posted
 942  * blocking reads will stay, however new ones will fail.
 943  */
 944 static void evdev_mark_dead(struct evdev *evdev)
 945 {
 946         mutex_lock(&evdev->mutex);
 947         evdev->exist = 0;
 948         mutex_unlock(&evdev->mutex);
 949 }
 950
 951 static void evdev_cleanup(struct evdev *evdev)
 952 {
 953         struct input_handle *handle = &evdev->handle;
 954
 955         evdev_mark_dead(evdev);
 956         evdev_hangup(evdev);
 957         evdev_remove_chrdev(evdev);
 958
 959         /* evdev is marked dead so no one else accesses evdev->open */
 960         if (evdev->open) {
 961                 input_flush_device(handle, NULL);
 962                 input_close_device(handle);
 963         }
 964 }
 965
 966 /*
 967  * Create new evdev device. Note that input core serializes calls
 968  * to connect and disconnect so we don't need to lock evdev_table here.
 969  */
 970 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
 971                          const struct input_device_id *id)
 972 {
 973         struct evdev *evdev;
 974         int minor;
 975         int error;
 976
 977         for (minor = 0; minor < EVDEV_MINORS; minor++)
 978                 if (!evdev_table[minor])
 979                         break;
 980
 981         if (minor == EVDEV_MINORS) {
 982                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 983                 return -ENFILE;
 984         }
 985
 986         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
 987         if (!evdev)
 988                 return -ENOMEM;
 989
 990         INIT_LIST_HEAD(&evdev->client_list);
 991         spin_lock_init(&evdev->client_lock);
 992         mutex_init(&evdev->mutex);
 993         init_waitqueue_head(&evdev->wait);
 994
 995         snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
 996         evdev->exist = 1;
 997         evdev->minor = minor;
 998
 999         evdev->handle.dev = input_get_device(dev);
1000         evdev->handle.name = evdev->name;
1001         evdev->handle.handler = handler;
1002         evdev->handle.private = evdev;
1003
1004         strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id));
1005         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
1006         evdev->dev.class = &input_class;
1007         evdev->dev.parent = &dev->dev;
1008         evdev->dev.release = evdev_free;
1009         device_initialize(&evdev->dev);
1010
1011         error = input_register_handle(&evdev->handle);
1012         if (error)
1013                 goto err_free_evdev;
1014
1015         error = evdev_install_chrdev(evdev);
1016         if (error)
1017                 goto err_unregister_handle;
1018
1019         error = device_add(&evdev->dev);
1020         if (error)
1021                 goto err_cleanup_evdev;
1022
1023         return 0;
1024
1025  err_cleanup_evdev:
1026         evdev_cleanup(evdev);
1027  err_unregister_handle:
1028         input_unregister_handle(&evdev->handle);
1029  err_free_evdev:
1030         put_device(&evdev->dev);
1031         return error;
1032 }
1033
1034 static void evdev_disconnect(struct input_handle *handle)
1035 {
1036         struct evdev *evdev = handle->private;
1037
1038         device_del(&evdev->dev);
1039         evdev_cleanup(evdev);
1040         input_unregister_handle(handle);
1041         put_device(&evdev->dev);
1042 }
1043
1044 static const struct input_device_id evdev_ids[] = {
1045         { .driver_info = 1 },   /* Matches all devices */
1046         { },                    /* Terminating zero entry */
1047 };
1048
1049 MODULE_DEVICE_TABLE(input, evdev_ids);
1050
1051 static struct input_handler evdev_handler = {
1052         .event          = evdev_event,
1053         .connect        = evdev_connect,
1054         .disconnect     = evdev_disconnect,
1055         .fops           = &evdev_fops,
1056         .minor          = EVDEV_MINOR_BASE,
1057         .name           = "evdev",
1058         .id_table       = evdev_ids,
1059 };
1060
1061 static int __init evdev_init(void)
1062 {
1063         return input_register_handler(&evdev_handler);
1064 }
1065
1066 static void __exit evdev_exit(void)
1067 {
1068         input_unregister_handler(&evdev_handler);
1069 }
1070
1071 module_init(evdev_init);
1072 module_exit(evdev_exit);
1073
1074 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1075 MODULE_DESCRIPTION("Input driver event char devices");
1076 MODULE_LICENSE("GPL");