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                 cond_resched();
 602         }
 603
 604         return bytes;
 605 }
 606
 607 static ssize_t uinput_write(struct file *file, const char __user *buffer,
 608                             size_t count, loff_t *ppos)
 609 {
 610         struct uinput_device *udev = file->private_data;
 611         int retval;
 612
 613         if (count == 0)
 614                 return 0;
 615
 616         retval = mutex_lock_interruptible(&udev->mutex);
 617         if (retval)
 618                 return retval;
 619
 620         retval = udev->state == UIST_CREATED ?
 621                         uinput_inject_events(udev, buffer, count) :
 622                         uinput_setup_device_legacy(udev, buffer, count);
 623
 624         mutex_unlock(&udev->mutex);
 625
 626         return retval;
 627 }
 628
 629 static bool uinput_fetch_next_event(struct uinput_device *udev,
 630                                     struct input_event *event)
 631 {
 632         bool have_event;
 633
 634         spin_lock_irq(&udev->dev->event_lock);
 635
 636         have_event = udev->head != udev->tail;
 637         if (have_event) {
 638                 *event = udev->buff[udev->tail];
 639                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
 640         }
 641
 642         spin_unlock_irq(&udev->dev->event_lock);
 643
 644         return have_event;
 645 }
 646
 647 static ssize_t uinput_events_to_user(struct uinput_device *udev,
 648                                      char __user *buffer, size_t count)
 649 {
 650         struct input_event event;
 651         size_t read = 0;
 652
 653         while (read + input_event_size() <= count &&
 654                uinput_fetch_next_event(udev, &event)) {
 655
 656                 if (input_event_to_user(buffer + read, &event))
 657                         return -EFAULT;
 658
 659                 read += input_event_size();
 660         }
 661
 662         return read;
 663 }
 664
 665 static ssize_t uinput_read(struct file *file, char __user *buffer,
 666                            size_t count, loff_t *ppos)
 667 {
 668         struct uinput_device *udev = file->private_data;
 669         ssize_t retval;
 670
 671         if (count != 0 && count < input_event_size())
 672                 return -EINVAL;
 673
 674         do {
 675                 retval = mutex_lock_interruptible(&udev->mutex);
 676                 if (retval)
 677                         return retval;
 678
 679                 if (udev->state != UIST_CREATED)
 680                         retval = -ENODEV;
 681                 else if (udev->head == udev->tail &&
 682                          (file->f_flags & O_NONBLOCK))
 683                         retval = -EAGAIN;
 684                 else
 685                         retval = uinput_events_to_user(udev, buffer, count);
 686
 687                 mutex_unlock(&udev->mutex);
 688
 689                 if (retval || count == 0)
 690                         break;
 691
 692                 if (!(file->f_flags & O_NONBLOCK))
 693                         retval = wait_event_interruptible(udev->waitq,
 694                                                   udev->head != udev->tail ||
 695                                                   udev->state != UIST_CREATED);
 696         } while (retval == 0);
 697
 698         return retval;
 699 }
 700
 701 static __poll_t uinput_poll(struct file *file, poll_table *wait)
 702 {
 703         struct uinput_device *udev = file->private_data;
 704
 705         poll_wait(file, &udev->waitq, wait);
 706
 707         if (udev->head != udev->tail)
 708                 return EPOLLIN | EPOLLRDNORM;
 709
 710         return 0;
 711 }
 712
 713 static int uinput_release(struct inode *inode, struct file *file)
 714 {
 715         struct uinput_device *udev = file->private_data;
 716
 717         uinput_destroy_device(udev);
 718         kfree(udev);
 719
 720         return 0;
 721 }
 722
 723 #ifdef CONFIG_COMPAT
 724 struct uinput_ff_upload_compat {
 725         __u32                   request_id;
 726         __s32                   retval;
 727         struct ff_effect_compat effect;
 728         struct ff_effect_compat old;
 729 };
 730
 731 static int uinput_ff_upload_to_user(char __user *buffer,
 732                                     const struct uinput_ff_upload *ff_up)
 733 {
 734         if (in_compat_syscall()) {
 735                 struct uinput_ff_upload_compat ff_up_compat;
 736
 737                 ff_up_compat.request_id = ff_up->request_id;
 738                 ff_up_compat.retval = ff_up->retval;
 739                 /*
 740                  * It so happens that the pointer that gives us the trouble
 741                  * is the last field in the structure. Since we don't support
 742                  * custom waveforms in uinput anyway we can just copy the whole
 743                  * thing (to the compat size) and ignore the pointer.
 744                  */
 745                 memcpy(&ff_up_compat.effect, &ff_up->effect,
 746                         sizeof(struct ff_effect_compat));
 747                 memcpy(&ff_up_compat.old, &ff_up->old,
 748                         sizeof(struct ff_effect_compat));
 749
 750                 if (copy_to_user(buffer, &ff_up_compat,
 751                                  sizeof(struct uinput_ff_upload_compat)))
 752                         return -EFAULT;
 753         } else {
 754                 if (copy_to_user(buffer, ff_up,
 755                                  sizeof(struct uinput_ff_upload)))
 756                         return -EFAULT;
 757         }
 758
 759         return 0;
 760 }
 761
 762 static int uinput_ff_upload_from_user(const char __user *buffer,
 763                                       struct uinput_ff_upload *ff_up)
 764 {
 765         if (in_compat_syscall()) {
 766                 struct uinput_ff_upload_compat ff_up_compat;
 767
 768                 if (copy_from_user(&ff_up_compat, buffer,
 769                                    sizeof(struct uinput_ff_upload_compat)))
 770                         return -EFAULT;
 771
 772                 ff_up->request_id = ff_up_compat.request_id;
 773                 ff_up->retval = ff_up_compat.retval;
 774                 memcpy(&ff_up->effect, &ff_up_compat.effect,
 775                         sizeof(struct ff_effect_compat));
 776                 memcpy(&ff_up->old, &ff_up_compat.old,
 777                         sizeof(struct ff_effect_compat));
 778
 779         } else {
 780                 if (copy_from_user(ff_up, buffer,
 781                                    sizeof(struct uinput_ff_upload)))
 782                         return -EFAULT;
 783         }
 784
 785         return 0;
 786 }
 787
 788 #else
 789
 790 static int uinput_ff_upload_to_user(char __user *buffer,
 791                                     const struct uinput_ff_upload *ff_up)
 792 {
 793         if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
 794                 return -EFAULT;
 795
 796         return 0;
 797 }
 798
 799 static int uinput_ff_upload_from_user(const char __user *buffer,
 800                                       struct uinput_ff_upload *ff_up)
 801 {
 802         if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
 803                 return -EFAULT;
 804
 805         return 0;
 806 }
 807
 808 #endif
 809
 810 #define uinput_set_bit(_arg, _bit, _max)                \
 811 ({                                                      \
 812         int __ret = 0;                                  \
 813         if (udev->state == UIST_CREATED)                \
 814                 __ret =  -EINVAL;                       \
 815         else if ((_arg) > (_max))                       \
 816                 __ret = -EINVAL;                        \
 817         else set_bit((_arg), udev->dev->_bit);          \
 818         __ret;                                          \
 819 })
 820
 821 static int uinput_str_to_user(void __user *dest, const char *str,
 822                               unsigned int maxlen)
 823 {
 824         char __user *p = dest;
 825         int len, ret;
 826
 827         if (!str)
 828                 return -ENOENT;
 829
 830         if (maxlen == 0)
 831                 return -EINVAL;
 832
 833         len = strlen(str) + 1;
 834         if (len > maxlen)
 835                 len = maxlen;
 836
 837         ret = copy_to_user(p, str, len);
 838         if (ret)
 839                 return -EFAULT;
 840
 841         /* force terminating '\0' */
 842         ret = put_user(0, p + len - 1);
 843         return ret ? -EFAULT : len;
 844 }
 845
 846 static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
 847                                  unsigned long arg, void __user *p)
 848 {
 849         int                     retval;
 850         struct uinput_device    *udev = file->private_data;
 851         struct uinput_ff_upload ff_up;
 852         struct uinput_ff_erase  ff_erase;
 853         struct uinput_request   *req;
 854         char                    *phys;
 855         const char              *name;
 856         unsigned int            size;
 857
 858         retval = mutex_lock_interruptible(&udev->mutex);
 859         if (retval)
 860                 return retval;
 861
 862         if (!udev->dev) {
 863                 udev->dev = input_allocate_device();
 864                 if (!udev->dev) {
 865                         retval = -ENOMEM;
 866                         goto out;
 867                 }
 868         }
 869
 870         switch (cmd) {
 871         case UI_GET_VERSION:
 872                 if (put_user(UINPUT_VERSION, (unsigned int __user *)p))
 873                         retval = -EFAULT;
 874                 goto out;
 875
 876         case UI_DEV_CREATE:
 877                 retval = uinput_create_device(udev);
 878                 goto out;
 879
 880         case UI_DEV_DESTROY:
 881                 uinput_destroy_device(udev);
 882                 goto out;
 883
 884         case UI_DEV_SETUP:
 885                 retval = uinput_dev_setup(udev, p);
 886                 goto out;
 887
 888         /* UI_ABS_SETUP is handled in the variable size ioctls */
 889
 890         case UI_SET_EVBIT:
 891                 retval = uinput_set_bit(arg, evbit, EV_MAX);
 892                 goto out;
 893
 894         case UI_SET_KEYBIT:
 895                 retval = uinput_set_bit(arg, keybit, KEY_MAX);
 896                 goto out;
 897
 898         case UI_SET_RELBIT:
 899                 retval = uinput_set_bit(arg, relbit, REL_MAX);
 900                 goto out;
 901
 902         case UI_SET_ABSBIT:
 903                 retval = uinput_set_bit(arg, absbit, ABS_MAX);
 904                 goto out;
 905
 906         case UI_SET_MSCBIT:
 907                 retval = uinput_set_bit(arg, mscbit, MSC_MAX);
 908                 goto out;
 909
 910         case UI_SET_LEDBIT:
 911                 retval = uinput_set_bit(arg, ledbit, LED_MAX);
 912                 goto out;
 913
 914         case UI_SET_SNDBIT:
 915                 retval = uinput_set_bit(arg, sndbit, SND_MAX);
 916                 goto out;
 917
 918         case UI_SET_FFBIT:
 919                 retval = uinput_set_bit(arg, ffbit, FF_MAX);
 920                 goto out;
 921
 922         case UI_SET_SWBIT:
 923                 retval = uinput_set_bit(arg, swbit, SW_MAX);
 924                 goto out;
 925
 926         case UI_SET_PROPBIT:
 927                 retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
 928                 goto out;
 929
 930         case UI_SET_PHYS:
 931                 if (udev->state == UIST_CREATED) {
 932                         retval = -EINVAL;
 933                         goto out;
 934                 }
 935
 936                 phys = strndup_user(p, 1024);
 937                 if (IS_ERR(phys)) {
 938                         retval = PTR_ERR(phys);
 939                         goto out;
 940                 }
 941
 942                 kfree(udev->dev->phys);
 943                 udev->dev->phys = phys;
 944                 goto out;
 945
 946         case UI_BEGIN_FF_UPLOAD:
 947                 retval = uinput_ff_upload_from_user(p, &ff_up);
 948                 if (retval)
 949                         goto out;
 950
 951                 req = uinput_request_find(udev, ff_up.request_id);
 952                 if (!req || req->code != UI_FF_UPLOAD ||
 953                     !req->u.upload.effect) {
 954                         retval = -EINVAL;
 955                         goto out;
 956                 }
 957
 958                 ff_up.retval = 0;
 959                 ff_up.effect = *req->u.upload.effect;
 960                 if (req->u.upload.old)
 961                         ff_up.old = *req->u.upload.old;
 962                 else
 963                         memset(&ff_up.old, 0, sizeof(struct ff_effect));
 964
 965                 retval = uinput_ff_upload_to_user(p, &ff_up);
 966                 goto out;
 967
 968         case UI_BEGIN_FF_ERASE:
 969                 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
 970                         retval = -EFAULT;
 971                         goto out;
 972                 }
 973
 974                 req = uinput_request_find(udev, ff_erase.request_id);
 975                 if (!req || req->code != UI_FF_ERASE) {
 976                         retval = -EINVAL;
 977                         goto out;
 978                 }
 979
 980                 ff_erase.retval = 0;
 981                 ff_erase.effect_id = req->u.effect_id;
 982                 if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
 983                         retval = -EFAULT;
 984                         goto out;
 985                 }
 986
 987                 goto out;
 988
 989         case UI_END_FF_UPLOAD:
 990                 retval = uinput_ff_upload_from_user(p, &ff_up);
 991                 if (retval)
 992                         goto out;
 993
 994                 req = uinput_request_find(udev, ff_up.request_id);
 995                 if (!req || req->code != UI_FF_UPLOAD ||
 996                     !req->u.upload.effect) {
 997                         retval = -EINVAL;
 998                         goto out;
 999                 }
1000
1001                 req->retval = ff_up.retval;
1002                 complete(&req->done);
1003                 goto out;
1004
1005         case UI_END_FF_ERASE:
1006                 if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
1007                         retval = -EFAULT;
1008                         goto out;
1009                 }
1010
1011                 req = uinput_request_find(udev, ff_erase.request_id);
1012                 if (!req || req->code != UI_FF_ERASE) {
1013                         retval = -EINVAL;
1014                         goto out;
1015                 }
1016
1017                 req->retval = ff_erase.retval;
1018                 complete(&req->done);
1019                 goto out;
1020         }
1021
1022         size = _IOC_SIZE(cmd);
1023
1024         /* Now check variable-length commands */
1025         switch (cmd & ~IOCSIZE_MASK) {
1026         case UI_GET_SYSNAME(0):
1027                 if (udev->state != UIST_CREATED) {
1028                         retval = -ENOENT;
1029                         goto out;
1030                 }
1031                 name = dev_name(&udev->dev->dev);
1032                 retval = uinput_str_to_user(p, name, size);
1033                 goto out;
1034
1035         case UI_ABS_SETUP & ~IOCSIZE_MASK:
1036                 retval = uinput_abs_setup(udev, p, size);
1037                 goto out;
1038         }
1039
1040         retval = -EINVAL;
1041  out:
1042         mutex_unlock(&udev->mutex);
1043         return retval;
1044 }
1045
1046 static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1047 {
1048         return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
1049 }
1050
1051 #ifdef CONFIG_COMPAT
1052
1053 #define UI_SET_PHYS_COMPAT      _IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)
1054
1055 static long uinput_compat_ioctl(struct file *file,
1056                                 unsigned int cmd, unsigned long arg)
1057 {
1058         if (cmd == UI_SET_PHYS_COMPAT)
1059                 cmd = UI_SET_PHYS;
1060
1061         return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
1062 }
1063 #endif
1064
1065 static const struct file_operations uinput_fops = {
1066         .owner          = THIS_MODULE,
1067         .open           = uinput_open,
1068         .release        = uinput_release,
1069         .read           = uinput_read,
1070         .write          = uinput_write,
1071         .poll           = uinput_poll,
1072         .unlocked_ioctl = uinput_ioctl,
1073 #ifdef CONFIG_COMPAT
1074         .compat_ioctl   = uinput_compat_ioctl,
1075 #endif
1076         .llseek         = no_llseek,
1077 };
1078
1079 static struct miscdevice uinput_misc = {
1080         .fops           = &uinput_fops,
1081         .minor          = UINPUT_MINOR,
1082         .name           = UINPUT_NAME,
1083 };
1084 module_misc_device(uinput_misc);
1085
1086 MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
1087 MODULE_ALIAS("devname:" UINPUT_NAME);
1088
1089 MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
1090 MODULE_DESCRIPTION("User level driver support for input subsystem");
1091 MODULE_LICENSE("GPL");