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