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