drivers/input/misc/uinput.c

   1 /*
   2  *  User level driver support for input subsystem
   3  *
   4  * Heavily based on evdev.c by Vojtech Pavlik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
  21  *
  22  * Changes/Revisions:
  23  *      0.4     01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
  24  *              - add UI_GET_SYSNAME ioctl
  25  *      0.3     09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
  26  *              - updated ff support for the changes in kernel interface
  27  *              - added MODULE_VERSION
  28  *      0.2     16/10/2004 (Micah Dowty <micah@navi.cx>)
  29  *              - added force feedback support
  30  *              - added UI_SET_PHYS
  31  *      0.1     20/06/2002
  32  *              - first public version
  33  */
  34 #include <uapi/linux/uinput.h>
  35 #include <linux/poll.h>
  36 #include <linux/sched.h>
  37 #include <linux/slab.h>
  38 #include <linux/module.h>
  39 #include <linux/init.h>
  40 #include <linux/fs.h>
  41 #include <linux/miscdevice.h>
  42 #include <linux/overflow.h>
  43 #include <linux/input/mt.h>
  44 #include "../input-compat.h"
  45
  46 #define UINPUT_NAME             "uinput"
  47 #define UINPUT_BUFFER_SIZE      16
  48 #define UINPUT_NUM_REQUESTS     16
  49
  50 enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED };
  51
  52 struct uinput_request {
  53         unsigned int            id;
  54         unsigned int            code;   /* UI_FF_UPLOAD, UI_FF_ERASE */
  55
  56         int                     retval;
  57         struct completion       done;
  58
  59         union {
  60                 unsigned int    effect_id;
  61                 struct {
  62                         struct ff_effect *effect;
  63                         struct ff_effect *old;
  64                 } upload;
  65         } u;
  66 };
  67
  68 struct uinput_device {
  69         struct input_dev        *dev;
  70         struct mutex            mutex;
  71         enum uinput_state       state;
  72         wait_queue_head_t       waitq;
  73         unsigned char           ready;
  74         unsigned char           head;
  75         unsigned char           tail;
  76         struct input_event      buff[UINPUT_BUFFER_SIZE];
  77         unsigned int            ff_effects_max;
  78
  79         struct uinput_request   *requests[UINPUT_NUM_REQUESTS];
  80         wait_queue_head_t       requests_waitq;
  81         spinlock_t              requests_lock;
  82 };
  83
  84 static int uinput_dev_event(struct input_dev *dev,
  85                             unsigned int type, unsigned int code, int value)
  86 {
  87         struct uinput_device    *udev = input_get_drvdata(dev);
  88         struct timespec64       ts;
  89
  90         ktime_get_ts64(&ts);
  91
  92         udev->buff[udev->head] = (struct input_event) {
  93                 .input_event_sec = ts.tv_sec,
  94                 .input_event_usec = ts.tv_nsec / NSEC_PER_USEC,
  95                 .type = type,
  96                 .code = code,
  97                 .value = value,
  98         };
  99
 100         udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
 101
 102         wake_up_interruptible(&udev->waitq);
 103
 104         return 0;
 105 }
 106
 107 /* Atomically allocate an ID for the given request. Returns 0 on success. */
 108 static bool uinput_request_alloc_id(struct uinput_device *udev,
 109                                     struct uinput_request *request)
 110 {
 111         unsigned int id;
 112         bool reserved = false;
 113
 114         spin_lock(&udev->requests_lock);
 115
 116         for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
 117                 if (!udev->requests[id]) {
 118                         request->id = id;
 119                         udev->requests[id] = request;
 120                         reserved = true;
 121                         break;
 122                 }
 123         }
 124
 125         spin_unlock(&udev->requests_lock);
 126         return reserved;
 127 }
 128
 129 static struct uinput_request *uinput_request_find(struct uinput_device *udev,
 130                                                   unsigned int id)
 131 {
 132         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
 133         if (id >= UINPUT_NUM_REQUESTS)
 134                 return NULL;
 135
 136         return udev->requests[id];
 137 }
 138
 139 static int uinput_request_reserve_slot(struct uinput_device *udev,
 140                                        struct uinput_request *request)
 141 {
 142         /* Allocate slot. If none are available right away, wait. */
 143         return wait_event_interruptible(udev->requests_waitq,
 144                                         uinput_request_alloc_id(udev, request));
 145 }
 146
 147 static void uinput_request_release_slot(struct uinput_device *udev,
 148                                         unsigned int id)
 149 {
 150         /* Mark slot as available */
 151         spin_lock(&udev->requests_lock);
 152         udev->requests[id] = NULL;
 153         spin_unlock(&udev->requests_lock);
 154
 155         wake_up(&udev->requests_waitq);
 156 }
 157
 158 static int uinput_request_send(struct uinput_device *udev,
 159                                struct uinput_request *request)
 160 {
 161         int retval;
 162
 163         retval = mutex_lock_interruptible(&udev->mutex);
 164         if (retval)
 165                 return retval;
 166
 167         if (udev->state != UIST_CREATED) {
 168                 retval = -ENODEV;
 169                 goto out;
 170         }
 171
 172         init_completion(&request->done);
 173
 174         /*
 175          * Tell our userspace application about this new request
 176          * by queueing an input event.
 177          */
 178         uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);
 179
 180  out:
 181         mutex_unlock(&udev->mutex);
 182         return retval;
 183 }
 184
 185 static int uinput_request_submit(struct uinput_device *udev,
 186                                  struct uinput_request *request)
 187 {
 188         int retval;
 189
 190         retval = uinput_request_reserve_slot(udev, request);
 191         if (retval)
 192                 return retval;
 193
 194         retval = uinput_request_send(udev, request);
 195         if (retval)
 196                 goto out;
 197
 198         if (!wait_for_completion_timeout(&request->done, 30 * HZ)) {
 199                 retval = -ETIMEDOUT;
 200                 goto out;
 201         }
 202
 203         retval = request->retval;
 204
 205  out:
 206         uinput_request_release_slot(udev, request->id);
 207         return retval;
 208 }
 209
 210 /*
 211  * Fail all outstanding requests so handlers don't wait for the userspace
 212  * to finish processing them.
 213  */
 214 static void uinput_flush_requests(struct uinput_device *udev)
 215 {
 216         struct uinput_request *request;
 217         int i;
 218
 219         spin_lock(&udev->requests_lock);
 220
 221         for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
 222                 request = udev->requests[i];
 223                 if (request) {
 224                         request->retval = -ENODEV;
 225                         complete(&request->done);
 226                 }
 227         }
 228
 229         spin_unlock(&udev->requests_lock);
 230 }
 231
 232 static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
 233 {
 234         uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
 235 }
 236
 237 static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
 238 {
 239         uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
 240 }
 241
 242 static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
 243 {
 244         return uinput_dev_event(dev, EV_FF, effect_id, value);
 245 }
 246
 247 static int uinput_dev_upload_effect(struct input_dev *dev,
 248                                     struct ff_effect *effect,
 249                                     struct ff_effect *old)
 250 {
 251         struct uinput_device *udev = input_get_drvdata(dev);
 252         struct uinput_request request;
 253
 254         /*
 255          * uinput driver does not currently support periodic effects with
 256          * custom waveform since it does not have a way to pass buffer of
 257          * samples (custom_data) to userspace. If ever there is a device
 258          * supporting custom waveforms we would need to define an additional
 259          * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
 260          */
 261         if (effect->type == FF_PERIODIC &&
 262                         effect->u.periodic.waveform == FF_CUSTOM)
 263                 return -EINVAL;
 264
 265         request.code = UI_FF_UPLOAD;
 266         request.u.upload.effect = effect;
 267         request.u.upload.old = old;
 268
 269         return uinput_request_submit(udev, &request);
 270 }
 271
 272 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 273 {
 274         struct uinput_device *udev = input_get_drvdata(dev);
 275         struct uinput_request request;
 276
 277         if (!test_bit(EV_FF, dev->evbit))
 278                 return -ENOSYS;
 279
 280         request.code = UI_FF_ERASE;
 281         request.u.effect_id = effect_id;
 282
 283         return uinput_request_submit(udev, &request);
 284 }
 285
 286 static int uinput_dev_flush(struct input_dev *dev, struct file *file)
 287 {
 288         /*
 289          * If we are called with file == NULL that means we are tearing
 290          * down the device, and therefore we can not handle FF erase
 291          * requests: either we are handling UI_DEV_DESTROY (and holding
 292          * the udev->mutex), or the file descriptor is closed and there is
 293          * nobody on the other side anymore.
 294          */
 295         return file ? input_ff_flush(dev, file) : 0;
 296 }
 297
 298 static void uinput_destroy_device(struct uinput_device *udev)
 299 {
 300         const char *name, *phys;
 301         struct input_dev *dev = udev->dev;
 302         enum uinput_state old_state = udev->state;
 303
 304         udev->state = UIST_NEW_DEVICE;
 305
 306         if (dev) {
 307                 name = dev->name;
 308                 phys = dev->phys;
 309                 if (old_state == UIST_CREATED) {
 310                         uinput_flush_requests(udev);
 311                         input_unregister_device(dev);
 312                 } else {
 313                         input_free_device(dev);
 314                 }
 315                 kfree(name);
 316                 kfree(phys);
 317                 udev->dev = NULL;
 318         }
 319 }
 320
 321 static int uinput_create_device(struct uinput_device *udev)
 322 {
 323         struct input_dev *dev = udev->dev;
 324         int error, nslot;
 325
 326         if (udev->state != UIST_SETUP_COMPLETE) {
 327                 printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
 328                 return -EINVAL;
 329         }
 330
 331         if (test_bit(EV_ABS, dev->evbit)) {
 332                 input_alloc_absinfo(dev);
 333                 if (!dev->absinfo) {
 334                         error = -EINVAL;
 335                         goto fail1;
 336                 }
 337
 338                 if (test_bit(ABS_MT_SLOT, dev->absbit)) {
 339                         nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
 340                         error = input_mt_init_slots(dev, nslot, 0);
 341                         if (error)
 342                                 goto fail1;
 343                 } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
 344                         input_set_events_per_packet(dev, 60);
 345                 }
 346         }
 347
 348         if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) {
 349                 printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n",
 350                         UINPUT_NAME);
 351                 error = -EINVAL;
 352                 goto fail1;
 353         }
 354
 355         if (udev->ff_effects_max) {
 356                 error = input_ff_create(dev, udev->ff_effects_max);
 357                 if (error)
 358                         goto fail1;
 359
 360                 dev->ff->upload = uinput_dev_upload_effect;
 361                 dev->ff->erase = uinput_dev_erase_effect;
 362                 dev->ff->playback = uinput_dev_playback;
 363                 dev->ff->set_gain = uinput_dev_set_gain;
 364                 dev->ff->set_autocenter = uinput_dev_set_autocenter;
 365                 /*
 366                  * The standard input_ff_flush() implementation does
 367                  * not quite work for uinput as we can't reasonably
 368                  * handle FF requests during device teardown.
 369                  */
 370                 dev->flush = uinput_dev_flush;
 371         }
 372
 373         dev->event = uinput_dev_event;
 374
 375         input_set_drvdata(udev->dev, udev);
 376
 377         error = input_register_device(udev->dev);
 378         if (error)
 379                 goto fail2;
 380
 381         udev->state = UIST_CREATED;
 382
 383         return 0;
 384
 385  fail2: input_ff_destroy(dev);
 386  fail1: uinput_destroy_device(udev);
 387         return error;
 388 }
 389
 390 static int uinput_open(struct inode *inode, struct file *file)
 391 {
 392         struct uinput_device *newdev;
 393
 394         newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
 395         if (!newdev)
 396                 return -ENOMEM;
 397
 398         mutex_init(&newdev->mutex);
 399         spin_lock_init(&newdev->requests_lock);
 400         init_waitqueue_head(&newdev->requests_waitq);
 401         init_waitqueue_head(&newdev->waitq);
 402         newdev->state = UIST_NEW_DEVICE;
 403
 404         file->private_data = newdev;
 405         nonseekable_open(inode, file);
 406
 407         return 0;
 408 }
 409
 410 static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
 411                                    const struct input_absinfo *abs)
 412 {
 413         int min, max, range;
 414
 415         min = abs->minimum;
 416         max = abs->maximum;
 417
 418         if ((min != 0 || max != 0) && max < min) {
 419                 printk(KERN_DEBUG
 420                        "%s: invalid abs[%02x] min:%d max:%d\n",
 421                        UINPUT_NAME, code, min, max);
 422                 return -EINVAL;
 423         }
 424
 425         if (!check_sub_overflow(max, min, &range) && abs->flat > range) {
 426                 printk(KERN_DEBUG
 427                        "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
 428                        UINPUT_NAME, code, abs->flat, min, max);
 429                 return -EINVAL;
 430         }
 431
 432         return 0;
 433 }
 434
 435 static int uinput_validate_absbits(struct input_dev *dev)
 436 {
 437         unsigned int cnt;
 438         int error;
 439
 440         if (!test_bit(EV_ABS, dev->evbit))
 441                 return 0;
 442
 443         /*
 444          * Check if absmin/absmax/absfuzz/absflat are sane.
 445          */
 446
 447         for_each_set_bit(cnt, dev->absbit, ABS_CNT) {
 448                 if (!dev->absinfo)
 449                         return -EINVAL;
 450
 451                 error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]);
 452                 if (error)
 453                         return error;
 454         }
 455
 456         return 0;
 457 }
 458
 459 static int uinput_dev_setup(struct uinput_device *udev,
 460                             struct uinput_setup __user *arg)
 461 {
 462         struct uinput_setup setup;
 463         struct input_dev *dev;
 464
 465         if (udev->state == UIST_CREATED)
 466                 return -EINVAL;
 467
 468         if (copy_from_user(&setup, arg, sizeof(setup)))
 469                 return -EFAULT;
 470
 471         if (!setup.name[0])
 472                 return -EINVAL;
 473
 474         dev = udev->dev;
 475         dev->id = setup.id;
 476         udev->ff_effects_max = setup.ff_effects_max;
 477
 478         kfree(dev->name);
 479         dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL);
 480         if (!dev->name)
 481                 return -ENOMEM;
 482
 483         udev->state = UIST_SETUP_COMPLETE;
 484         return 0;
 485 }
 486
 487 static int uinput_abs_setup(struct uinput_device *udev,
 488                             struct uinput_setup __user *arg, size_t size)
 489 {
 490         struct uinput_abs_setup setup = {};
 491         struct input_dev *dev;
 492         int error;
 493
 494         if (size > sizeof(setup))
 495                 return -E2BIG;
 496
 497         if (udev->state == UIST_CREATED)
 498                 return -EINVAL;
 499
 500         if (copy_from_user(&setup, arg, size))
 501                 return -EFAULT;
 502
 503         if (setup.code > ABS_MAX)
 504                 return -ERANGE;
 505
 506         dev = udev->dev;
 507
 508         error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo);
 509         if (error)
 510                 return error;
 511
 512         input_alloc_absinfo(dev);
 513         if (!dev->absinfo)
 514                 return -ENOMEM;
 515
 516         set_bit(setup.code, dev->absbit);
 517         dev->absinfo[setup.code] = setup.absinfo;
 518         return 0;
 519 }
 520
 521 /* legacy setup via write() */
 522 static int uinput_setup_device_legacy(struct uinput_device *udev,
 523                                       const char __user *buffer, size_t count)
 524 {
 525         struct uinput_user_dev  *user_dev;
 526         struct input_dev        *dev;
 527         int                     i;
 528         int                     retval;
 529
 530         if (count != sizeof(struct uinput_user_dev))
 531                 return -EINVAL;
 532
 533         if (!udev->dev) {
 534                 udev->dev = input_allocate_device();
 535                 if (!udev->dev)
 536                         return -ENOMEM;
 537         }
 538
 539         dev = udev->dev;
 540
 541         user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
 542         if (IS_ERR(user_dev))
 543                 return PTR_ERR(user_dev);
 544
 545         udev->ff_effects_max = user_dev->ff_effects_max;
 546
 547         /* Ensure name is filled in */
 548         if (!user_dev->name[0]) {
 549                 retval = -EINVAL;
 550                 goto exit;
 551         }
 552
 553         kfree(dev->name);
 554         dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
 555                              GFP_KERNEL);
 556         if (!dev->name) {
 557                 retval = -ENOMEM;
 558                 goto exit;
 559         }
 560
 561         dev->id.bustype = user_dev->id.bustype;
 562         dev->id.vendor  = user_dev->id.vendor;
 563         dev->id.product = user_dev->id.product;
 564         dev->id.version = user_dev->id.version;
 565
 566         for (i = 0; i < ABS_CNT; i++) {
 567                 input_abs_set_max(dev, i, user_dev->absmax[i]);
 568                 input_abs_set_min(dev, i, user_dev->absmin[i]);
 569                 input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
 570                 input_abs_set_flat(dev, i, user_dev->absflat[i]);
 571         }
 572
 573         retval = uinput_validate_absbits(dev);
 574         if (retval < 0)
 575                 goto exit;
 576
 577         udev->state = UIST_SETUP_COMPLETE;
 578         retval = count;
 579
 580  exit:
 581         kfree(user_dev);
 582         return retval;
 583 }
 584
 585 static ssize_t uinput_inject_events(struct uinput_device *udev,
 586                                     const char __user *buffer, size_t count)
 587 {
 588         struct input_event ev;
 589         size_t bytes = 0;
 590
 591         if (count != 0 && count < input_event_size())
 592                 return -EINVAL;
 593
 594         while (bytes + input_event_size() <= count) {
 595                 /*
 596                  * Note that even if some events were fetched successfully
 597                  * we are still going to return EFAULT instead of partial
 598                  * count to let userspace know that it got it's buffers
 599                  * all wrong.
 600                  */
 601                 if (input_event_from_user(buffer + bytes, &ev))
 602                         return -EFAULT;
 603
 604                 input_event(udev->dev, ev.type, ev.code, ev.value);
 605                 bytes += input_event_size();
 606                 cond_resched();
 607         }
 608
 609         return bytes;
 610 }
 611
 612 static ssize_t uinput_write(struct file *file, const char __user *buffer,
 613                             size_t count, loff_t *ppos)
 614 {
 615         struct uinput_device *udev = file->private_data;
 616         int retval;
 617
 618         if (count == 0)
 619                 return 0;
 620
 621         retval = mutex_lock_interruptible(&udev->mutex);
 622         if (retval)
 623                 return retval;
 624
 625         retval = udev->state == UIST_CREATED ?
 626                         uinput_inject_events(udev, buffer, count) :
 627                         uinput_setup_device_legacy(udev, buffer, count);
 628
 629         mutex_unlock(&udev->mutex);
 630
 631         return retval;
 632 }
 633
 634 static bool uinput_fetch_next_event(struct uinput_device *udev,
 635                                     struct input_event *event)
 636 {
 637         bool have_event;
 638
 639         spin_lock_irq(&udev->dev->event_lock);
 640
 641         have_event = udev->head != udev->tail;
 642         if (have_event) {
 643                 *event = udev->buff[udev->tail];
 644                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 645         }
 646
 647         spin_unlock_irq(&udev->dev->event_lock);
 648
 649         return have_event;
 650 }
 651
 652 static ssize_t uinput_events_to_user(struct uinput_device *udev,
 653                                      char __user *buffer, size_t count)
 654 {
 655         struct input_event event;
 656         size_t read = 0;
 657
 658         while (read + input_event_size() <= count &&
 659                uinput_fetch_next_event(udev, &event)) {
 660
 661                 if (input_event_to_user(buffer + read, &event))
 662                         return -EFAULT;
 663
 664                 read += input_event_size();
 665         }
 666
 667         return read;
 668 }
 669
 670 static ssize_t uinput_read(struct file *file, char __user *buffer,
 671                            size_t count, loff_t *ppos)
 672 {
 673         struct uinput_device *udev = file->private_data;
 674         ssize_t retval;
 675
 676         if (count != 0 && count < input_event_size())
 677                 return -EINVAL;
 678
 679         do {
 680                 retval = mutex_lock_interruptible(&udev->mutex);
 681                 if (retval)
 682                         return retval;
 683
 684                 if (udev->state != UIST_CREATED)
 685                         retval = -ENODEV;
 686                 else if (udev->head == udev->tail &&
 687                          (file->f_flags & O_NONBLOCK))
 688                         retval = -EAGAIN;
 689                 else
 690                         retval = uinput_events_to_user(udev, buffer, count);
 691
 692                 mutex_unlock(&udev->mutex);
 693
 694                 if (retval || count == 0)
 695                         break;
 696
 697                 if (!(file->f_flags & O_NONBLOCK))
 698                         retval = wait_event_interruptible(udev->waitq,
 699                                                   udev->head != udev->tail ||
 700                                                   udev->state != UIST_CREATED);
 701         } while (retval == 0);
 702
 703         return retval;
 704 }
 705
 706 static __poll_t uinput_poll(struct file *file, poll_table *wait)
 707 {
 708         struct uinput_device *udev = file->private_data;
 709
 710         poll_wait(file, &udev->waitq, wait);
 711
 712         if (udev->head != udev->tail)
 713                 return EPOLLIN | EPOLLRDNORM;
 714
 715         return 0;
 716 }
 717
 718 static int uinput_release(struct inode *inode, struct file *file)
 719 {
 720         struct uinput_device *udev = file->private_data;
 721
 722         uinput_destroy_device(udev);
 723         kfree(udev);
 724
 725         return 0;
 726 }
 727
 728 #ifdef CONFIG_COMPAT
 729 struct uinput_ff_upload_compat {
 730         __u32                   request_id;
 731         __s32                   retval;
 732         struct ff_effect_compat effect;
 733         struct ff_effect_compat old;
 734 };
 735
 736 static int uinput_ff_upload_to_user(char __user *buffer,
 737                                     const struct uinput_ff_upload *ff_up)
 738 {
 739         if (in_compat_syscall()) {
 740                 struct uinput_ff_upload_compat ff_up_compat;
 741
 742                 ff_up_compat.request_id = ff_up->request_id;
 743                 ff_up_compat.retval = ff_up->retval;
 744                 /*
 745                  * It so happens that the pointer that gives us the trouble
 746                  * is the last field in the structure. Since we don't support
 747                  * custom waveforms in uinput anyway we can just copy the whole
 748                  * thing (to the compat size) and ignore the pointer.
 749                  */
 750                 memcpy(&ff_up_compat.effect, &ff_up->effect,
 751                         sizeof(struct ff_effect_compat));
 752                 memcpy(&ff_up_compat.old, &ff_up->old,
 753                         sizeof(struct ff_effect_compat));
 754
 755                 if (copy_to_user(buffer, &ff_up_compat,
 756                                  sizeof(struct uinput_ff_upload_compat)))
 757                         return -EFAULT;
 758         } else {
 759                 if (copy_to_user(buffer, ff_up,
 760                                  sizeof(struct uinput_ff_upload)))
 761                         return -EFAULT;
 762         }
 763
 764         return 0;
 765 }
 766
 767 static int uinput_ff_upload_from_user(const char __user *buffer,
 768                                       struct uinput_ff_upload *ff_up)
 769 {
 770         if (in_compat_syscall()) {
 771                 struct uinput_ff_upload_compat ff_up_compat;
 772
 773                 if (copy_from_user(&ff_up_compat, buffer,
 774                                    sizeof(struct uinput_ff_upload_compat)))
 775                         return -EFAULT;
 776
 777                 ff_up->request_id = ff_up_compat.request_id;
 778                 ff_up->retval = ff_up_compat.retval;
 779                 memcpy(&ff_up->effect, &ff_up_compat.effect,
 780                         sizeof(struct ff_effect_compat));
 781                 memcpy(&ff_up->old, &ff_up_compat.old,
 782                         sizeof(struct ff_effect_compat));
 783
 784         } else {
 785                 if (copy_from_user(ff_up, buffer,
 786                                    sizeof(struct uinput_ff_upload)))
 787                         return -EFAULT;
 788         }
 789
 790         return 0;
 791 }
 792
 793 #else
 794
 795 static int uinput_ff_upload_to_user(char __user *buffer,
 796                                     const struct uinput_ff_upload *ff_up)
 797 {
 798         if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
 799                 return -EFAULT;
 800
 801         return 0;
 802 }
 803
 804 static int uinput_ff_upload_from_user(const char __user *buffer,
 805                                       struct uinput_ff_upload *ff_up)
 806 {
 807         if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
 808                 return -EFAULT;
 809
 810         return 0;
 811 }
 812
 813 #endif
 814
 815 #define uinput_set_bit(_arg, _bit, _max)                \
 816 ({                                                      \
 817         int __ret = 0;                                  \
 818         if (udev->state == UIST_CREATED)                \
 819                 __ret =  -EINVAL;                       \
 820         else if ((_arg) > (_max))                       \
 821                 __ret = -EINVAL;                        \
 822         else set_bit((_arg), udev->dev->_bit);          \
 823         __ret;                                          \
 824 })
 825
 826 static int uinput_str_to_user(void __user *dest, const char *str,
 827                               unsigned int maxlen)
 828 {
 829         char __user *p = dest;
 830         int len, ret;
 831
 832         if (!str)
 833                 return -ENOENT;
 834
 835         if (maxlen == 0)
 836                 return -EINVAL;
 837
 838         len = strlen(str) + 1;
 839         if (len > maxlen)
 840                 len = maxlen;
 841
 842         ret = copy_to_user(p, str, len);
 843         if (ret)
 844                 return -EFAULT;
 845
 846         /* force terminating '\0' */
 847         ret = put_user(0, p + len - 1);
 848         return ret ? -EFAULT : len;
 849 }
 850
 851 static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
 852                                  unsigned long arg, void __user *p)
 853 {
 854         int                     retval;
 855         struct uinput_device    *udev = file->private_data;
 856         struct uinput_ff_upload ff_up;
 857         struct uinput_ff_erase  ff_erase;
 858         struct uinput_request   *req;
 859         char                    *phys;
 860         const char              *name;
 861         unsigned int            size;
 862
 863         retval = mutex_lock_interruptible(&udev->mutex);
 864         if (retval)
 865                 return retval;
 866
 867         if (!udev->dev) {
 868                 udev->dev = input_allocate_device();
 869                 if (!udev->dev) {
 870                         retval = -ENOMEM;
 871                         goto out;
 872                 }
 873         }
 874
 875         switch (cmd) {
 876         case UI_GET_VERSION:
 877                 if (put_user(UINPUT_VERSION, (unsigned int __user *)p))
 878                         retval = -EFAULT;
 879                 goto out;
 880
 881         case UI_DEV_CREATE:
 882                 retval = uinput_create_device(udev);
 883                 goto out;
 884
 885         case UI_DEV_DESTROY:
 886                 uinput_destroy_device(udev);
 887                 goto out;
 888
 889         case UI_DEV_SETUP:
 890                 retval = uinput_dev_setup(udev, p);
 891                 goto out;
 892
 893         /* UI_ABS_SETUP is handled in the variable size ioctls */
 894
 895         case UI_SET_EVBIT:
 896                 retval = uinput_set_bit(arg, evbit, EV_MAX);
 897                 goto out;
 898
 899         case UI_SET_KEYBIT:
 900                 retval = uinput_set_bit(arg, keybit, KEY_MAX);
 901                 goto out;
 902
 903         case UI_SET_RELBIT:
 904                 retval = uinput_set_bit(arg, relbit, REL_MAX);
 905                 goto out;
 906
 907         case UI_SET_ABSBIT:
 908                 retval = uinput_set_bit(arg, absbit, ABS_MAX);
 909                 goto out;
 910
 911         case UI_SET_MSCBIT:
 912                 retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 913                 goto out;
 914
 915         case UI_SET_LEDBIT:
 916                 retval = uinput_set_bit(arg, ledbit, LED_MAX);
 917                 goto out;
 918
 919         case UI_SET_SNDBIT:
 920                 retval = uinput_set_bit(arg, sndbit, SND_MAX);
 921                 goto out;
 922
 923         case UI_SET_FFBIT:
 924                 retval = uinput_set_bit(arg, ffbit, FF_MAX);
 925                 goto out;
 926
 927         case UI_SET_SWBIT:
 928                 retval = uinput_set_bit(arg, swbit, SW_MAX);
 929                 goto out;
 930
 931         case UI_SET_PROPBIT:
 932                 retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
 933                 goto out;
 934
 935         case UI_SET_PHYS:
 936                 if (udev->state == UIST_CREATED) {
 937                         retval = -EINVAL;
 938                         goto out;
 939                 }
 940
 941                 phys = strndup_user(p, 1024);
 942                 if (IS_ERR(phys)) {
 943                         retval = PTR_ERR(phys);
 944                         goto out;
 945                 }
 946
 947                 kfree(udev->dev->phys);
 948                 udev->dev->phys = phys;
 949                 goto out;
 950
 951         case UI_BEGIN_FF_UPLOAD:
 952                 retval = uinput_ff_upload_from_user(p, &ff_up);
 953                 if (retval)
 954                         goto out;
 955
 956                 req = uinput_request_find(udev, ff_up.request_id);
 957                 if (!req || req->code != UI_FF_UPLOAD ||
 958                     !req->u.upload.effect) {
 959                         retval = -EINVAL;
 960                         goto out;
 961                 }
 962
 963                 ff_up.retval = 0;
 964                 ff_up.effect = *req->u.upload.effect;
 965                 if (req->u.upload.old)
 966                         ff_up.old = *req->u.upload.old;
 967                 else
 968                         memset(&ff_up.old, 0, sizeof(struct ff_effect));
 969
 970                 retval = uinput_ff_upload_to_user(p, &ff_up);
 971                 goto out;
 972
 973         case UI_BEGIN_FF_ERASE:
 974                 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 975                         retval = -EFAULT;
 976                         goto out;
 977                 }
 978
 979                 req = uinput_request_find(udev, ff_erase.request_id);
 980                 if (!req || req->code != UI_FF_ERASE) {
 981                         retval = -EINVAL;
 982                         goto out;
 983                 }
 984
 985                 ff_erase.retval = 0;
 986                 ff_erase.effect_id = req->u.effect_id;
 987                 if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 988                         retval = -EFAULT;
 989                         goto out;
 990                 }
 991
 992                 goto out;
 993
 994         case UI_END_FF_UPLOAD:
 995                 retval = uinput_ff_upload_from_user(p, &ff_up);
 996                 if (retval)
 997                         goto out;
 998
 999                 req = uinput_request_find(udev, ff_up.request_id);
1000                 if (!req || req->code != UI_FF_UPLOAD ||
1001                     !req->u.upload.effect) {
1002                         retval = -EINVAL;
1003                         goto out;
1004                 }
1005
1006                 req->retval = ff_up.retval;
1007                 complete(&req->done);
1008                 goto out;
1009
1010         case UI_END_FF_ERASE:
1011                 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
1012                         retval = -EFAULT;
1013                         goto out;
1014                 }
1015
1016                 req = uinput_request_find(udev, ff_erase.request_id);
1017                 if (!req || req->code != UI_FF_ERASE) {
1018                         retval = -EINVAL;
1019                         goto out;
1020                 }
1021
1022                 req->retval = ff_erase.retval;
1023                 complete(&req->done);
1024                 goto out;
1025         }
1026
1027         size = _IOC_SIZE(cmd);
1028
1029         /* Now check variable-length commands */
1030         switch (cmd & ~IOCSIZE_MASK) {
1031         case UI_GET_SYSNAME(0):
1032                 if (udev->state != UIST_CREATED) {
1033                         retval = -ENOENT;
1034                         goto out;
1035                 }
1036                 name = dev_name(&udev->dev->dev);
1037                 retval = uinput_str_to_user(p, name, size);
1038                 goto out;
1039
1040         case UI_ABS_SETUP & ~IOCSIZE_MASK:
1041                 retval = uinput_abs_setup(udev, p, size);
1042                 goto out;
1043         }
1044
1045         retval = -EINVAL;
1046  out:
1047         mutex_unlock(&udev->mutex);
1048         return retval;
1049 }
1050
1051 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1052 {
1053         return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
1054 }
1055
1056 #ifdef CONFIG_COMPAT
1057
1058 /*
1059  * These IOCTLs change their size and thus their numbers between
1060  * 32 and 64 bits.
1061  */
1062 #define UI_SET_PHYS_COMPAT              \
1063         _IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)
1064 #define UI_BEGIN_FF_UPLOAD_COMPAT       \
1065         _IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload_compat)
1066 #define UI_END_FF_UPLOAD_COMPAT         \
1067         _IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload_compat)
1068
1069 static long uinput_compat_ioctl(struct file *file,
1070                                 unsigned int cmd, unsigned long arg)
1071 {
1072         switch (cmd) {
1073         case UI_SET_PHYS_COMPAT:
1074                 cmd = UI_SET_PHYS;
1075                 break;
1076         case UI_BEGIN_FF_UPLOAD_COMPAT:
1077                 cmd = UI_BEGIN_FF_UPLOAD;
1078                 break;
1079         case UI_END_FF_UPLOAD_COMPAT:
1080                 cmd = UI_END_FF_UPLOAD;
1081                 break;
1082         }
1083
1084         return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
1085 }
1086 #endif
1087
1088 static const struct file_operations uinput_fops = {
1089         .owner          = THIS_MODULE,
1090         .open           = uinput_open,
1091         .release        = uinput_release,
1092         .read           = uinput_read,
1093         .write          = uinput_write,
1094         .poll           = uinput_poll,
1095         .unlocked_ioctl = uinput_ioctl,
1096 #ifdef CONFIG_COMPAT
1097         .compat_ioctl   = uinput_compat_ioctl,
1098 #endif
1099         .llseek         = no_llseek,
1100 };
1101
1102 static struct miscdevice uinput_misc = {
1103         .fops           = &uinput_fops,
1104         .minor          = UINPUT_MINOR,
1105         .name           = UINPUT_NAME,
1106 };
1107 module_misc_device(uinput_misc);
1108
1109 MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
1110 MODULE_ALIAS("devname:" UINPUT_NAME);
1111
1112 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
1113 MODULE_DESCRIPTION("User level driver support for input subsystem");
1114 MODULE_LICENSE("GPL");