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