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