drivers/input/misc/uinput.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  User level driver support for input subsystem
   4  *
   5  * Heavily based on evdev.c by Vojtech Pavlik
   6  *
   7  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
   8  *
   9  * Changes/Revisions:
  10  *      0.4     01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
  11  *              - add UI_GET_SYSNAME ioctl
  12  *      0.3     09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
  13  *              - updated ff support for the changes in kernel interface
  14  *              - added MODULE_VERSION
  15  *      0.2     16/10/2004 (Micah Dowty <micah@navi.cx>)
  16  *              - added force feedback support
  17  *              - added UI_SET_PHYS
  18  *      0.1     20/06/2002
  19  *              - first public version
  20  */
  21 #include <uapi/linux/uinput.h>
  22 #include <linux/poll.h>
  23 #include <linux/sched.h>
  24 #include <linux/slab.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/fs.h>
  28 #include <linux/miscdevice.h>
  29 #include <linux/overflow.h>
  30 #include <linux/input/mt.h>
  31 #include "../input-compat.h"
  32
  33 #define UINPUT_NAME             "uinput"
  34 #define UINPUT_BUFFER_SIZE      16
  35 #define UINPUT_NUM_REQUESTS     16
  36
  37 enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED };
  38
  39 struct uinput_request {
  40         unsigned int            id;
  41         unsigned int            code;   /* UI_FF_UPLOAD, UI_FF_ERASE */
  42
  43         int                     retval;
  44         struct completion       done;
  45
  46         union {
  47                 unsigned int    effect_id;
  48                 struct {
  49                         struct ff_effect *effect;
  50                         struct ff_effect *old;
  51                 } upload;
  52         } u;
  53 };
  54
  55 struct uinput_device {
  56         struct input_dev        *dev;
  57         struct mutex            mutex;
  58         enum uinput_state       state;
  59         wait_queue_head_t       waitq;
  60         unsigned char           ready;
  61         unsigned char           head;
  62         unsigned char           tail;
  63         struct input_event      buff[UINPUT_BUFFER_SIZE];
  64         unsigned int            ff_effects_max;
  65
  66         struct uinput_request   *requests[UINPUT_NUM_REQUESTS];
  67         wait_queue_head_t       requests_waitq;
  68         spinlock_t              requests_lock;
  69 };
  70
  71 static int uinput_dev_event(struct input_dev *dev,
  72                             unsigned int type, unsigned int code, int value)
  73 {
  74         struct uinput_device    *udev = input_get_drvdata(dev);
  75         struct timespec64       ts;
  76
  77         udev->buff[udev->head].type = type;
  78         udev->buff[udev->head].code = code;
  79         udev->buff[udev->head].value = value;
  80         ktime_get_ts64(&ts);
  81         udev->buff[udev->head].input_event_sec = ts.tv_sec;
  82         udev->buff[udev->head].input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
  83         udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
  84
  85         wake_up_interruptible(&udev->waitq);
  86
  87         return 0;
  88 }
  89
  90 /* Atomically allocate an ID for the given request. Returns 0 on success. */
  91 static bool uinput_request_alloc_id(struct uinput_device *udev,
  92                                     struct uinput_request *request)
  93 {
  94         unsigned int id;
  95         bool reserved = false;
  96
  97         spin_lock(&udev->requests_lock);
  98
  99         for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
 100                 if (!udev->requests[id]) {
 101                         request->id = id;
 102                         udev->requests[id] = request;
 103                         reserved = true;
 104                         break;
 105                 }
 106         }
 107
 108         spin_unlock(&udev->requests_lock);
 109         return reserved;
 110 }
 111
 112 static struct uinput_request *uinput_request_find(struct uinput_device *udev,
 113                                                   unsigned int id)
 114 {
 115         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
 116         if (id >= UINPUT_NUM_REQUESTS)
 117                 return NULL;
 118
 119         return udev->requests[id];
 120 }
 121
 122 static int uinput_request_reserve_slot(struct uinput_device *udev,
 123                                        struct uinput_request *request)
 124 {
 125         /* Allocate slot. If none are available right away, wait. */
 126         return wait_event_interruptible(udev->requests_waitq,
 127                                         uinput_request_alloc_id(udev, request));
 128 }
 129
 130 static void uinput_request_release_slot(struct uinput_device *udev,
 131                                         unsigned int id)
 132 {
 133         /* Mark slot as available */
 134         spin_lock(&udev->requests_lock);
 135         udev->requests[id] = NULL;
 136         spin_unlock(&udev->requests_lock);
 137
 138         wake_up(&udev->requests_waitq);
 139 }
 140
 141 static int uinput_request_send(struct uinput_device *udev,
 142                                struct uinput_request *request)
 143 {
 144         int retval;
 145
 146         retval = mutex_lock_interruptible(&udev->mutex);
 147         if (retval)
 148                 return retval;
 149
 150         if (udev->state != UIST_CREATED) {
 151                 retval = -ENODEV;
 152                 goto out;
 153         }
 154
 155         init_completion(&request->done);
 156
 157         /*
 158          * Tell our userspace application about this new request
 159          * by queueing an input event.
 160          */
 161         uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);
 162
 163  out:
 164         mutex_unlock(&udev->mutex);
 165         return retval;
 166 }
 167
 168 static int uinput_request_submit(struct uinput_device *udev,
 169                                  struct uinput_request *request)
 170 {
 171         int retval;
 172
 173         retval = uinput_request_reserve_slot(udev, request);
 174         if (retval)
 175                 return retval;
 176
 177         retval = uinput_request_send(udev, request);
 178         if (retval)
 179                 goto out;
 180
 181         if (!wait_for_completion_timeout(&request->done, 30 * HZ)) {
 182                 retval = -ETIMEDOUT;
 183                 goto out;
 184         }
 185
 186         retval = request->retval;
 187
 188  out:
 189         uinput_request_release_slot(udev, request->id);
 190         return retval;
 191 }
 192
 193 /*
 194  * Fail all outstanding requests so handlers don't wait for the userspace
 195  * to finish processing them.
 196  */
 197 static void uinput_flush_requests(struct uinput_device *udev)
 198 {
 199         struct uinput_request *request;
 200         int i;
 201
 202         spin_lock(&udev->requests_lock);
 203
 204         for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
 205                 request = udev->requests[i];
 206                 if (request) {
 207                         request->retval = -ENODEV;
 208                         complete(&request->done);
 209                 }
 210         }
 211
 212         spin_unlock(&udev->requests_lock);
 213 }
 214
 215 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
 216 {
 217         uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
 218 }
 219
 220 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
 221 {
 222         uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
 223 }
 224
 225 static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
 226 {
 227         return uinput_dev_event(dev, EV_FF, effect_id, value);
 228 }
 229
 230 static int uinput_dev_upload_effect(struct input_dev *dev,
 231                                     struct ff_effect *effect,
 232                                     struct ff_effect *old)
 233 {
 234         struct uinput_device *udev = input_get_drvdata(dev);
 235         struct uinput_request request;
 236
 237         /*
 238          * uinput driver does not currently support periodic effects with
 239          * custom waveform since it does not have a way to pass buffer of
 240          * samples (custom_data) to userspace. If ever there is a device
 241          * supporting custom waveforms we would need to define an additional
 242          * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
 243          */
 244         if (effect->type == FF_PERIODIC &&
 245                         effect->u.periodic.waveform == FF_CUSTOM)
 246                 return -EINVAL;
 247
 248         request.code = UI_FF_UPLOAD;
 249         request.u.upload.effect = effect;
 250         request.u.upload.old = old;
 251
 252         return uinput_request_submit(udev, &request);
 253 }
 254
 255 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 256 {
 257         struct uinput_device *udev = input_get_drvdata(dev);
 258         struct uinput_request request;
 259
 260         if (!test_bit(EV_FF, dev->evbit))
 261                 return -ENOSYS;
 262
 263         request.code = UI_FF_ERASE;
 264         request.u.effect_id = effect_id;
 265
 266         return uinput_request_submit(udev, &request);
 267 }
 268
 269 static int uinput_dev_flush(struct input_dev *dev, struct file *file)
 270 {
 271         /*
 272          * If we are called with file == NULL that means we are tearing
 273          * down the device, and therefore we can not handle FF erase
 274          * requests: either we are handling UI_DEV_DESTROY (and holding
 275          * the udev->mutex), or the file descriptor is closed and there is
 276          * nobody on the other side anymore.
 277          */
 278         return file ? input_ff_flush(dev, file) : 0;
 279 }
 280
 281 static void uinput_destroy_device(struct uinput_device *udev)
 282 {
 283         const char *name, *phys;
 284         struct input_dev *dev = udev->dev;
 285         enum uinput_state old_state = udev->state;
 286
 287         udev->state = UIST_NEW_DEVICE;
 288
 289         if (dev) {
 290                 name = dev->name;
 291                 phys = dev->phys;
 292                 if (old_state == UIST_CREATED) {
 293                         uinput_flush_requests(udev);
 294                         input_unregister_device(dev);
 295                 } else {
 296                         input_free_device(dev);
 297                 }
 298                 kfree(name);
 299                 kfree(phys);
 300                 udev->dev = NULL;
 301         }
 302 }
 303
 304 static int uinput_create_device(struct uinput_device *udev)
 305 {
 306         struct input_dev *dev = udev->dev;
 307         int error, nslot;
 308
 309         if (udev->state != UIST_SETUP_COMPLETE) {
 310                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 311                 return -EINVAL;
 312         }
 313
 314         if (test_bit(EV_ABS, dev->evbit)) {
 315                 input_alloc_absinfo(dev);
 316                 if (!dev->absinfo) {
 317                         error = -EINVAL;
 318                         goto fail1;
 319                 }
 320
 321                 if (test_bit(ABS_MT_SLOT, dev->absbit)) {
 322                         nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
 323                         error = input_mt_init_slots(dev, nslot, 0);
 324                         if (error)
 325                                 goto fail1;
 326                 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
 327                         input_set_events_per_packet(dev, 60);
 328                 }
 329         }
 330
 331         if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) {
 332                 printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n",
 333                         UINPUT_NAME);
 334                 error = -EINVAL;
 335                 goto fail1;
 336         }
 337
 338         if (udev->ff_effects_max) {
 339                 error = input_ff_create(dev, udev->ff_effects_max);
 340                 if (error)
 341                         goto fail1;
 342
 343                 dev->ff->upload = uinput_dev_upload_effect;
 344                 dev->ff->erase = uinput_dev_erase_effect;
 345                 dev->ff->playback = uinput_dev_playback;
 346                 dev->ff->set_gain = uinput_dev_set_gain;
 347                 dev->ff->set_autocenter = uinput_dev_set_autocenter;
 348                 /*
 349                  * The standard input_ff_flush() implementation does
 350                  * not quite work for uinput as we can't reasonably
 351                  * handle FF requests during device teardown.
 352                  */
 353                 dev->flush = uinput_dev_flush;
 354         }
 355
 356         dev->event = uinput_dev_event;
 357
 358         input_set_drvdata(udev->dev, udev);
 359
 360         error = input_register_device(udev->dev);
 361         if (error)
 362                 goto fail2;
 363
 364         udev->state = UIST_CREATED;
 365
 366         return 0;
 367
 368  fail2: input_ff_destroy(dev);
 369  fail1: uinput_destroy_device(udev);
 370         return error;
 371 }
 372
 373 static int uinput_open(struct inode *inode, struct file *file)
 374 {
 375         struct uinput_device *newdev;
 376
 377         newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 378         if (!newdev)
 379                 return -ENOMEM;
 380
 381         mutex_init(&newdev->mutex);
 382         spin_lock_init(&newdev->requests_lock);
 383         init_waitqueue_head(&newdev->requests_waitq);
 384         init_waitqueue_head(&newdev->waitq);
 385         newdev->state = UIST_NEW_DEVICE;
 386
 387         file->private_data = newdev;
 388         stream_open(inode, file);
 389
 390         return 0;
 391 }
 392
 393 static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
 394                                    const struct input_absinfo *abs)
 395 {
 396         int min, max, range;
 397
 398         min = abs->minimum;
 399         max = abs->maximum;
 400
 401         if ((min != 0 || max != 0) && max < min) {
 402                 printk(KERN_DEBUG
 403                        "%s: invalid abs[%02x] min:%d max:%d\n",
 404                        UINPUT_NAME, code, min, max);
 405                 return -EINVAL;
 406         }
 407
 408         if (!check_sub_overflow(max, min, &range) && abs->flat > range) {
 409                 printk(KERN_DEBUG
 410                        "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
 411                        UINPUT_NAME, code, abs->flat, min, max);
 412                 return -EINVAL;
 413         }
 414
 415         return 0;
 416 }
 417
 418 static int uinput_validate_absbits(struct input_dev *dev)
 419 {
 420         unsigned int cnt;
 421         int error;
 422
 423         if (!test_bit(EV_ABS, dev->evbit))
 424                 return 0;
 425
 426         /*
 427          * Check if absmin/absmax/absfuzz/absflat are sane.
 428          */
 429
 430         for_each_set_bit(cnt, dev->absbit, ABS_CNT) {
 431                 if (!dev->absinfo)
 432                         return -EINVAL;
 433
 434                 error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]);
 435                 if (error)
 436                         return error;
 437         }
 438
 439         return 0;
 440 }
 441
 442 static int uinput_dev_setup(struct uinput_device *udev,
 443                             struct uinput_setup __user *arg)
 444 {
 445         struct uinput_setup setup;
 446         struct input_dev *dev;
 447
 448         if (udev->state == UIST_CREATED)
 449                 return -EINVAL;
 450
 451         if (copy_from_user(&setup, arg, sizeof(setup)))
 452                 return -EFAULT;
 453
 454         if (!setup.name[0])
 455                 return -EINVAL;
 456
 457         dev = udev->dev;
 458         dev->id = setup.id;
 459         udev->ff_effects_max = setup.ff_effects_max;
 460
 461         kfree(dev->name);
 462         dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL);
 463         if (!dev->name)
 464                 return -ENOMEM;
 465
 466         udev->state = UIST_SETUP_COMPLETE;
 467         return 0;
 468 }
 469
 470 static int uinput_abs_setup(struct uinput_device *udev,
 471                             struct uinput_setup __user *arg, size_t size)
 472 {
 473         struct uinput_abs_setup setup = {};
 474         struct input_dev *dev;
 475         int error;
 476
 477         if (size > sizeof(setup))
 478                 return -E2BIG;
 479
 480         if (udev->state == UIST_CREATED)
 481                 return -EINVAL;
 482
 483         if (copy_from_user(&setup, arg, size))
 484                 return -EFAULT;
 485
 486         if (setup.code > ABS_MAX)
 487                 return -ERANGE;
 488
 489         dev = udev->dev;
 490
 491         error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo);
 492         if (error)
 493                 return error;
 494
 495         input_alloc_absinfo(dev);
 496         if (!dev->absinfo)
 497                 return -ENOMEM;
 498
 499         set_bit(setup.code, dev->absbit);
 500         dev->absinfo[setup.code] = setup.absinfo;
 501         return 0;
 502 }
 503
 504 /* legacy setup via write() */
 505 static int uinput_setup_device_legacy(struct uinput_device *udev,
 506                                       const char __user *buffer, size_t count)
 507 {
 508         struct uinput_user_dev  *user_dev;
 509         struct input_dev        *dev;
 510         int                     i;
 511         int                     retval;
 512
 513         if (count != sizeof(struct uinput_user_dev))
 514                 return -EINVAL;
 515
 516         if (!udev->dev) {
 517                 udev->dev = input_allocate_device();
 518                 if (!udev->dev)
 519                         return -ENOMEM;
 520         }
 521
 522         dev = udev->dev;
 523
 524         user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
 525         if (IS_ERR(user_dev))
 526                 return PTR_ERR(user_dev);
 527
 528         udev->ff_effects_max = user_dev->ff_effects_max;
 529
 530         /* Ensure name is filled in */
 531         if (!user_dev->name[0]) {
 532                 retval = -EINVAL;
 533                 goto exit;
 534         }
 535
 536         kfree(dev->name);
 537         dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
 538                              GFP_KERNEL);
 539         if (!dev->name) {
 540                 retval = -ENOMEM;
 541                 goto exit;
 542         }
 543
 544         dev->id.bustype = user_dev->id.bustype;
 545         dev->id.vendor  = user_dev->id.vendor;
 546         dev->id.product = user_dev->id.product;
 547         dev->id.version = user_dev->id.version;
 548
 549         for (i = 0; i < ABS_CNT; i++) {
 550                 input_abs_set_max(dev, i, user_dev->absmax[i]);
 551                 input_abs_set_min(dev, i, user_dev->absmin[i]);
 552                 input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
 553                 input_abs_set_flat(dev, i, user_dev->absflat[i]);
 554         }
 555
 556         retval = uinput_validate_absbits(dev);
 557         if (retval < 0)
 558                 goto exit;
 559
 560         udev->state = UIST_SETUP_COMPLETE;
 561         retval = count;
 562
 563  exit:
 564         kfree(user_dev);
 565         return retval;
 566 }
 567
 568 static ssize_t uinput_inject_events(struct uinput_device *udev,
 569                                     const char __user *buffer, size_t count)
 570 {
 571         struct input_event ev;
 572         size_t bytes = 0;
 573
 574         if (count != 0 && count < input_event_size())
 575                 return -EINVAL;
 576
 577         while (bytes + input_event_size() <= count) {
 578                 /*
 579                  * Note that even if some events were fetched successfully
 580                  * we are still going to return EFAULT instead of partial
 581                  * count to let userspace know that it got it's buffers
 582                  * all wrong.
 583                  */
 584                 if (input_event_from_user(buffer + bytes, &ev))
 585                         return -EFAULT;
 586
 587                 input_event(udev->dev, ev.type, ev.code, ev.value);
 588                 bytes += input_event_size();
 589                 cond_resched();
 590         }
 591
 592         return bytes;
 593 }
 594
 595 static ssize_t uinput_write(struct file *file, const char __user *buffer,
 596                             size_t count, loff_t *ppos)
 597 {
 598         struct uinput_device *udev = file->private_data;
 599         int retval;
 600
 601         if (count == 0)
 602                 return 0;
 603
 604         retval = mutex_lock_interruptible(&udev->mutex);
 605         if (retval)
 606                 return retval;
 607
 608         retval = udev->state == UIST_CREATED ?
 609                         uinput_inject_events(udev, buffer, count) :
 610                         uinput_setup_device_legacy(udev, buffer, count);
 611
 612         mutex_unlock(&udev->mutex);
 613
 614         return retval;
 615 }
 616
 617 static bool uinput_fetch_next_event(struct uinput_device *udev,
 618                                     struct input_event *event)
 619 {
 620         bool have_event;
 621
 622         spin_lock_irq(&udev->dev->event_lock);
 623
 624         have_event = udev->head != udev->tail;
 625         if (have_event) {
 626                 *event = udev->buff[udev->tail];
 627                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 628         }
 629
 630         spin_unlock_irq(&udev->dev->event_lock);
 631
 632         return have_event;
 633 }
 634
 635 static ssize_t uinput_events_to_user(struct uinput_device *udev,
 636                                      char __user *buffer, size_t count)
 637 {
 638         struct input_event event;
 639         size_t read = 0;
 640
 641         while (read + input_event_size() <= count &&
 642                uinput_fetch_next_event(udev, &event)) {
 643
 644                 if (input_event_to_user(buffer + read, &event))
 645                         return -EFAULT;
 646
 647                 read += input_event_size();
 648         }
 649
 650         return read;
 651 }
 652
 653 static ssize_t uinput_read(struct file *file, char __user *buffer,
 654                            size_t count, loff_t *ppos)
 655 {
 656         struct uinput_device *udev = file->private_data;
 657         ssize_t retval;
 658
 659         if (count != 0 && count < input_event_size())
 660                 return -EINVAL;
 661
 662         do {
 663                 retval = mutex_lock_interruptible(&udev->mutex);
 664                 if (retval)
 665                         return retval;
 666
 667                 if (udev->state != UIST_CREATED)
 668                         retval = -ENODEV;
 669                 else if (udev->head == udev->tail &&
 670                          (file->f_flags & O_NONBLOCK))
 671                         retval = -EAGAIN;
 672                 else
 673                         retval = uinput_events_to_user(udev, buffer, count);
 674
 675                 mutex_unlock(&udev->mutex);
 676
 677                 if (retval || count == 0)
 678                         break;
 679
 680                 if (!(file->f_flags & O_NONBLOCK))
 681                         retval = wait_event_interruptible(udev->waitq,
 682                                                   udev->head != udev->tail ||
 683                                                   udev->state != UIST_CREATED);
 684         } while (retval == 0);
 685
 686         return retval;
 687 }
 688
 689 static __poll_t uinput_poll(struct file *file, poll_table *wait)
 690 {
 691         struct uinput_device *udev = file->private_data;
 692
 693         poll_wait(file, &udev->waitq, wait);
 694
 695         if (udev->head != udev->tail)
 696                 return EPOLLIN | EPOLLRDNORM;
 697
 698         return 0;
 699 }
 700
 701 static int uinput_release(struct inode *inode, struct file *file)
 702 {
 703         struct uinput_device *udev = file->private_data;
 704
 705         uinput_destroy_device(udev);
 706         kfree(udev);
 707
 708         return 0;
 709 }
 710
 711 #ifdef CONFIG_COMPAT
 712 struct uinput_ff_upload_compat {
 713         __u32                   request_id;
 714         __s32                   retval;
 715         struct ff_effect_compat effect;
 716         struct ff_effect_compat old;
 717 };
 718
 719 static int uinput_ff_upload_to_user(char __user *buffer,
 720                                     const struct uinput_ff_upload *ff_up)
 721 {
 722         if (in_compat_syscall()) {
 723                 struct uinput_ff_upload_compat ff_up_compat;
 724
 725                 ff_up_compat.request_id = ff_up->request_id;
 726                 ff_up_compat.retval = ff_up->retval;
 727                 /*
 728                  * It so happens that the pointer that gives us the trouble
 729                  * is the last field in the structure. Since we don't support
 730                  * custom waveforms in uinput anyway we can just copy the whole
 731                  * thing (to the compat size) and ignore the pointer.
 732                  */
 733                 memcpy(&ff_up_compat.effect, &ff_up->effect,
 734                         sizeof(struct ff_effect_compat));
 735                 memcpy(&ff_up_compat.old, &ff_up->old,
 736                         sizeof(struct ff_effect_compat));
 737
 738                 if (copy_to_user(buffer, &ff_up_compat,
 739                                  sizeof(struct uinput_ff_upload_compat)))
 740                         return -EFAULT;
 741         } else {
 742                 if (copy_to_user(buffer, ff_up,
 743                                  sizeof(struct uinput_ff_upload)))
 744                         return -EFAULT;
 745         }
 746
 747         return 0;
 748 }
 749
 750 static int uinput_ff_upload_from_user(const char __user *buffer,
 751                                       struct uinput_ff_upload *ff_up)
 752 {
 753         if (in_compat_syscall()) {
 754                 struct uinput_ff_upload_compat ff_up_compat;
 755
 756                 if (copy_from_user(&ff_up_compat, buffer,
 757                                    sizeof(struct uinput_ff_upload_compat)))
 758                         return -EFAULT;
 759
 760                 ff_up->request_id = ff_up_compat.request_id;
 761                 ff_up->retval = ff_up_compat.retval;
 762                 memcpy(&ff_up->effect, &ff_up_compat.effect,
 763                         sizeof(struct ff_effect_compat));
 764                 memcpy(&ff_up->old, &ff_up_compat.old,
 765                         sizeof(struct ff_effect_compat));
 766
 767         } else {
 768                 if (copy_from_user(ff_up, buffer,
 769                                    sizeof(struct uinput_ff_upload)))
 770                         return -EFAULT;
 771         }
 772
 773         return 0;
 774 }
 775
 776 #else
 777
 778 static int uinput_ff_upload_to_user(char __user *buffer,
 779                                     const struct uinput_ff_upload *ff_up)
 780 {
 781         if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
 782                 return -EFAULT;
 783
 784         return 0;
 785 }
 786
 787 static int uinput_ff_upload_from_user(const char __user *buffer,
 788                                       struct uinput_ff_upload *ff_up)
 789 {
 790         if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
 791                 return -EFAULT;
 792
 793         return 0;
 794 }
 795
 796 #endif
 797
 798 #define uinput_set_bit(_arg, _bit, _max)                \
 799 ({                                                      \
 800         int __ret = 0;                                  \
 801         if (udev->state == UIST_CREATED)                \
 802                 __ret =  -EINVAL;                       \
 803         else if ((_arg) > (_max))                       \
 804                 __ret = -EINVAL;                        \
 805         else set_bit((_arg), udev->dev->_bit);          \
 806         __ret;                                          \
 807 })
 808
 809 static int uinput_str_to_user(void __user *dest, const char *str,
 810                               unsigned int maxlen)
 811 {
 812         char __user *p = dest;
 813         int len, ret;
 814
 815         if (!str)
 816                 return -ENOENT;
 817
 818         if (maxlen == 0)
 819                 return -EINVAL;
 820
 821         len = strlen(str) + 1;
 822         if (len > maxlen)
 823                 len = maxlen;
 824
 825         ret = copy_to_user(p, str, len);
 826         if (ret)
 827                 return -EFAULT;
 828
 829         /* force terminating '\0' */
 830         ret = put_user(0, p + len - 1);
 831         return ret ? -EFAULT : len;
 832 }
 833
 834 static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
 835                                  unsigned long arg, void __user *p)
 836 {
 837         int                     retval;
 838         struct uinput_device    *udev = file->private_data;
 839         struct uinput_ff_upload ff_up;
 840         struct uinput_ff_erase  ff_erase;
 841         struct uinput_request   *req;
 842         char                    *phys;
 843         const char              *name;
 844         unsigned int            size;
 845
 846         retval = mutex_lock_interruptible(&udev->mutex);
 847         if (retval)
 848                 return retval;
 849
 850         if (!udev->dev) {
 851                 udev->dev = input_allocate_device();
 852                 if (!udev->dev) {
 853                         retval = -ENOMEM;
 854                         goto out;
 855                 }
 856         }
 857
 858         switch (cmd) {
 859         case UI_GET_VERSION:
 860                 if (put_user(UINPUT_VERSION, (unsigned int __user *)p))
 861                         retval = -EFAULT;
 862                 goto out;
 863
 864         case UI_DEV_CREATE:
 865                 retval = uinput_create_device(udev);
 866                 goto out;
 867
 868         case UI_DEV_DESTROY:
 869                 uinput_destroy_device(udev);
 870                 goto out;
 871
 872         case UI_DEV_SETUP:
 873                 retval = uinput_dev_setup(udev, p);
 874                 goto out;
 875
 876         /* UI_ABS_SETUP is handled in the variable size ioctls */
 877
 878         case UI_SET_EVBIT:
 879                 retval = uinput_set_bit(arg, evbit, EV_MAX);
 880                 goto out;
 881
 882         case UI_SET_KEYBIT:
 883                 retval = uinput_set_bit(arg, keybit, KEY_MAX);
 884                 goto out;
 885
 886         case UI_SET_RELBIT:
 887                 retval = uinput_set_bit(arg, relbit, REL_MAX);
 888                 goto out;
 889
 890         case UI_SET_ABSBIT:
 891                 retval = uinput_set_bit(arg, absbit, ABS_MAX);
 892                 goto out;
 893
 894         case UI_SET_MSCBIT:
 895                 retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 896                 goto out;
 897
 898         case UI_SET_LEDBIT:
 899                 retval = uinput_set_bit(arg, ledbit, LED_MAX);
 900                 goto out;
 901
 902         case UI_SET_SNDBIT:
 903                 retval = uinput_set_bit(arg, sndbit, SND_MAX);
 904                 goto out;
 905
 906         case UI_SET_FFBIT:
 907                 retval = uinput_set_bit(arg, ffbit, FF_MAX);
 908                 goto out;
 909
 910         case UI_SET_SWBIT:
 911                 retval = uinput_set_bit(arg, swbit, SW_MAX);
 912                 goto out;
 913
 914         case UI_SET_PROPBIT:
 915                 retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
 916                 goto out;
 917
 918         case UI_SET_PHYS:
 919                 if (udev->state == UIST_CREATED) {
 920                         retval = -EINVAL;
 921                         goto out;
 922                 }
 923
 924                 phys = strndup_user(p, 1024);
 925                 if (IS_ERR(phys)) {
 926                         retval = PTR_ERR(phys);
 927                         goto out;
 928                 }
 929
 930                 kfree(udev->dev->phys);
 931                 udev->dev->phys = phys;
 932                 goto out;
 933
 934         case UI_BEGIN_FF_UPLOAD:
 935                 retval = uinput_ff_upload_from_user(p, &ff_up);
 936                 if (retval)
 937                         goto out;
 938
 939                 req = uinput_request_find(udev, ff_up.request_id);
 940                 if (!req || req->code != UI_FF_UPLOAD ||
 941                     !req->u.upload.effect) {
 942                         retval = -EINVAL;
 943                         goto out;
 944                 }
 945
 946                 ff_up.retval = 0;
 947                 ff_up.effect = *req->u.upload.effect;
 948                 if (req->u.upload.old)
 949                         ff_up.old = *req->u.upload.old;
 950                 else
 951                         memset(&ff_up.old, 0, sizeof(struct ff_effect));
 952
 953                 retval = uinput_ff_upload_to_user(p, &ff_up);
 954                 goto out;
 955
 956         case UI_BEGIN_FF_ERASE:
 957                 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 958                         retval = -EFAULT;
 959                         goto out;
 960                 }
 961
 962                 req = uinput_request_find(udev, ff_erase.request_id);
 963                 if (!req || req->code != UI_FF_ERASE) {
 964                         retval = -EINVAL;
 965                         goto out;
 966                 }
 967
 968                 ff_erase.retval = 0;
 969                 ff_erase.effect_id = req->u.effect_id;
 970                 if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 971                         retval = -EFAULT;
 972                         goto out;
 973                 }
 974
 975                 goto out;
 976
 977         case UI_END_FF_UPLOAD:
 978                 retval = uinput_ff_upload_from_user(p, &ff_up);
 979                 if (retval)
 980                         goto out;
 981
 982                 req = uinput_request_find(udev, ff_up.request_id);
 983                 if (!req || req->code != UI_FF_UPLOAD ||
 984                     !req->u.upload.effect) {
 985                         retval = -EINVAL;
 986                         goto out;
 987                 }
 988
 989                 req->retval = ff_up.retval;
 990                 complete(&req->done);
 991                 goto out;
 992
 993         case UI_END_FF_ERASE:
 994                 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 995                         retval = -EFAULT;
 996                         goto out;
 997                 }
 998
 999                 req = uinput_request_find(udev, ff_erase.request_id);
1000                 if (!req || req->code != UI_FF_ERASE) {
1001                         retval = -EINVAL;
1002                         goto out;
1003                 }
1004
1005                 req->retval = ff_erase.retval;
1006                 complete(&req->done);
1007                 goto out;
1008         }
1009
1010         size = _IOC_SIZE(cmd);
1011
1012         /* Now check variable-length commands */
1013         switch (cmd & ~IOCSIZE_MASK) {
1014         case UI_GET_SYSNAME(0):
1015                 if (udev->state != UIST_CREATED) {
1016                         retval = -ENOENT;
1017                         goto out;
1018                 }
1019                 name = dev_name(&udev->dev->dev);
1020                 retval = uinput_str_to_user(p, name, size);
1021                 goto out;
1022
1023         case UI_ABS_SETUP & ~IOCSIZE_MASK:
1024                 retval = uinput_abs_setup(udev, p, size);
1025                 goto out;
1026         }
1027
1028         retval = -EINVAL;
1029  out:
1030         mutex_unlock(&udev->mutex);
1031         return retval;
1032 }
1033
1034 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1035 {
1036         return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
1037 }
1038
1039 #ifdef CONFIG_COMPAT
1040
1041 /*
1042  * These IOCTLs change their size and thus their numbers between
1043  * 32 and 64 bits.
1044  */
1045 #define UI_SET_PHYS_COMPAT              \
1046         _IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)
1047 #define UI_BEGIN_FF_UPLOAD_COMPAT       \
1048         _IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload_compat)
1049 #define UI_END_FF_UPLOAD_COMPAT         \
1050         _IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload_compat)
1051
1052 static long uinput_compat_ioctl(struct file *file,
1053                                 unsigned int cmd, unsigned long arg)
1054 {
1055         switch (cmd) {
1056         case UI_SET_PHYS_COMPAT:
1057                 cmd = UI_SET_PHYS;
1058                 break;
1059         case UI_BEGIN_FF_UPLOAD_COMPAT:
1060                 cmd = UI_BEGIN_FF_UPLOAD;
1061                 break;
1062         case UI_END_FF_UPLOAD_COMPAT:
1063                 cmd = UI_END_FF_UPLOAD;
1064                 break;
1065         }
1066
1067         return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
1068 }
1069 #endif
1070
1071 static const struct file_operations uinput_fops = {
1072         .owner          = THIS_MODULE,
1073         .open           = uinput_open,
1074         .release        = uinput_release,
1075         .read           = uinput_read,
1076         .write          = uinput_write,
1077         .poll           = uinput_poll,
1078         .unlocked_ioctl = uinput_ioctl,
1079 #ifdef CONFIG_COMPAT
1080         .compat_ioctl   = uinput_compat_ioctl,
1081 #endif
1082         .llseek         = no_llseek,
1083 };
1084
1085 static struct miscdevice uinput_misc = {
1086         .fops           = &uinput_fops,
1087         .minor          = UINPUT_MINOR,
1088         .name           = UINPUT_NAME,
1089 };
1090 module_misc_device(uinput_misc);
1091
1092 MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
1093 MODULE_ALIAS("devname:" UINPUT_NAME);
1094
1095 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
1096 MODULE_DESCRIPTION("User level driver support for input subsystem");
1097 MODULE_LICENSE("GPL");