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