1 /* 2 * Event char devices, giving access to raw input device events. 3 * 4 * Copyright (c) 1999-2002 Vojtech Pavlik 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #define EVDEV_MINOR_BASE 64 14 #define EVDEV_MINORS 32 15 #define EVDEV_MIN_BUFFER_SIZE 64U 16 #define EVDEV_BUF_PACKETS 8 17 18 #include <linux/poll.h> 19 #include <linux/sched.h> 20 #include <linux/slab.h> 21 #include <linux/module.h> 22 #include <linux/init.h> 23 #include <linux/input/mt.h> 24 #include <linux/major.h> 25 #include <linux/device.h> 26 #include <linux/cdev.h> 27 #include "input-compat.h" 28 29 struct evdev { 30 int open; 31 struct input_handle handle; 32 wait_queue_head_t wait; 33 struct evdev_client __rcu *grab; 34 struct list_head client_list; 35 spinlock_t client_lock; /* protects client_list */ 36 struct mutex mutex; 37 struct device dev; 38 struct cdev cdev; 39 bool exist; 40 }; 41 42 struct evdev_client { 43 unsigned int head; 44 unsigned int tail; 45 unsigned int packet_head; /* [future] position of the first element of next packet */ 46 spinlock_t buffer_lock; /* protects access to buffer, head and tail */ 47 struct fasync_struct *fasync; 48 struct evdev *evdev; 49 struct list_head node; 50 int clkid; 51 unsigned int bufsize; 52 struct input_event buffer[]; 53 }; 54 55 static void __pass_event(struct evdev_client *client, 56 const struct input_event *event) 57 { 58 client->buffer[client->head++] = *event; 59 client->head &= client->bufsize - 1; 60 61 if (unlikely(client->head == client->tail)) { 62 /* 63 * This effectively "drops" all unconsumed events, leaving 64 * EV_SYN/SYN_DROPPED plus the newest event in the queue. 65 */ 66 client->tail = (client->head - 2) & (client->bufsize - 1); 67 68 client->buffer[client->tail].time = event->time; 69 client->buffer[client->tail].type = EV_SYN; 70 client->buffer[client->tail].code = SYN_DROPPED; 71 client->buffer[client->tail].value = 0; 72 73 client->packet_head = client->tail; 74 } 75 76 if (event->type == EV_SYN && event->code == SYN_REPORT) { 77 client->packet_head = client->head; 78 kill_fasync(&client->fasync, SIGIO, POLL_IN); 79 } 80 } 81 82 static void evdev_pass_values(struct evdev_client *client, 83 const struct input_value *vals, unsigned int count, 84 ktime_t mono, ktime_t real) 85 { 86 struct evdev *evdev = client->evdev; 87 const struct input_value *v; 88 struct input_event event; 89 bool wakeup = false; 90 91 event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ? 92 mono : real); 93 94 /* Interrupts are disabled, just acquire the lock. */ 95 spin_lock(&client->buffer_lock); 96 97 for (v = vals; v != vals + count; v++) { 98 event.type = v->type; 99 event.code = v->code; 100 event.value = v->value; 101 __pass_event(client, &event); 102 if (v->type == EV_SYN && v->code == SYN_REPORT) 103 wakeup = true; 104 } 105 106 spin_unlock(&client->buffer_lock); 107 108 if (wakeup) 109 wake_up_interruptible(&evdev->wait); 110 } 111 112 /* 113 * Pass incoming events to all connected clients. 114 */ 115 static void evdev_events(struct input_handle *handle, 116 const struct input_value *vals, unsigned int count) 117 { 118 struct evdev *evdev = handle->private; 119 struct evdev_client *client; 120 ktime_t time_mono, time_real; 121 122 time_mono = ktime_get(); 123 time_real = ktime_sub(time_mono, ktime_get_monotonic_offset()); 124 125 rcu_read_lock(); 126 127 client = rcu_dereference(evdev->grab); 128 129 if (client) 130 evdev_pass_values(client, vals, count, time_mono, time_real); 131 else 132 list_for_each_entry_rcu(client, &evdev->client_list, node) 133 evdev_pass_values(client, vals, count, 134 time_mono, time_real); 135 136 rcu_read_unlock(); 137 } 138 139 /* 140 * Pass incoming event to all connected clients. 141 */ 142 static void evdev_event(struct input_handle *handle, 143 unsigned int type, unsigned int code, int value) 144 { 145 struct input_value vals[] = { { type, code, value } }; 146 147 evdev_events(handle, vals, 1); 148 } 149 150 static int evdev_fasync(int fd, struct file *file, int on) 151 { 152 struct evdev_client *client = file->private_data; 153 154 return fasync_helper(fd, file, on, &client->fasync); 155 } 156 157 static int evdev_flush(struct file *file, fl_owner_t id) 158 { 159 struct evdev_client *client = file->private_data; 160 struct evdev *evdev = client->evdev; 161 int retval; 162 163 retval = mutex_lock_interruptible(&evdev->mutex); 164 if (retval) 165 return retval; 166 167 if (!evdev->exist) 168 retval = -ENODEV; 169 else 170 retval = input_flush_device(&evdev->handle, file); 171 172 mutex_unlock(&evdev->mutex); 173 return retval; 174 } 175 176 static void evdev_free(struct device *dev) 177 { 178 struct evdev *evdev = container_of(dev, struct evdev, dev); 179 180 input_put_device(evdev->handle.dev); 181 kfree(evdev); 182 } 183 184 /* 185 * Grabs an event device (along with underlying input device). 186 * This function is called with evdev->mutex taken. 187 */ 188 static int evdev_grab(struct evdev *evdev, struct evdev_client *client) 189 { 190 int error; 191 192 if (evdev->grab) 193 return -EBUSY; 194 195 error = input_grab_device(&evdev->handle); 196 if (error) 197 return error; 198 199 rcu_assign_pointer(evdev->grab, client); 200 201 return 0; 202 } 203 204 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client) 205 { 206 struct evdev_client *grab = rcu_dereference_protected(evdev->grab, 207 lockdep_is_held(&evdev->mutex)); 208 209 if (grab != client) 210 return -EINVAL; 211 212 rcu_assign_pointer(evdev->grab, NULL); 213 synchronize_rcu(); 214 input_release_device(&evdev->handle); 215 216 return 0; 217 } 218 219 static void evdev_attach_client(struct evdev *evdev, 220 struct evdev_client *client) 221 { 222 spin_lock(&evdev->client_lock); 223 list_add_tail_rcu(&client->node, &evdev->client_list); 224 spin_unlock(&evdev->client_lock); 225 } 226 227 static void evdev_detach_client(struct evdev *evdev, 228 struct evdev_client *client) 229 { 230 spin_lock(&evdev->client_lock); 231 list_del_rcu(&client->node); 232 spin_unlock(&evdev->client_lock); 233 synchronize_rcu(); 234 } 235 236 static int evdev_open_device(struct evdev *evdev) 237 { 238 int retval; 239 240 retval = mutex_lock_interruptible(&evdev->mutex); 241 if (retval) 242 return retval; 243 244 if (!evdev->exist) 245 retval = -ENODEV; 246 else if (!evdev->open++) { 247 retval = input_open_device(&evdev->handle); 248 if (retval) 249 evdev->open--; 250 } 251 252 mutex_unlock(&evdev->mutex); 253 return retval; 254 } 255 256 static void evdev_close_device(struct evdev *evdev) 257 { 258 mutex_lock(&evdev->mutex); 259 260 if (evdev->exist && !--evdev->open) 261 input_close_device(&evdev->handle); 262 263 mutex_unlock(&evdev->mutex); 264 } 265 266 /* 267 * Wake up users waiting for IO so they can disconnect from 268 * dead device. 269 */ 270 static void evdev_hangup(struct evdev *evdev) 271 { 272 struct evdev_client *client; 273 274 spin_lock(&evdev->client_lock); 275 list_for_each_entry(client, &evdev->client_list, node) 276 kill_fasync(&client->fasync, SIGIO, POLL_HUP); 277 spin_unlock(&evdev->client_lock); 278 279 wake_up_interruptible(&evdev->wait); 280 } 281 282 static int evdev_release(struct inode *inode, struct file *file) 283 { 284 struct evdev_client *client = file->private_data; 285 struct evdev *evdev = client->evdev; 286 287 mutex_lock(&evdev->mutex); 288 evdev_ungrab(evdev, client); 289 mutex_unlock(&evdev->mutex); 290 291 evdev_detach_client(evdev, client); 292 kfree(client); 293 294 evdev_close_device(evdev); 295 put_device(&evdev->dev); 296 297 return 0; 298 } 299 300 static unsigned int evdev_compute_buffer_size(struct input_dev *dev) 301 { 302 unsigned int n_events = 303 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS, 304 EVDEV_MIN_BUFFER_SIZE); 305 306 return roundup_pow_of_two(n_events); 307 } 308 309 static int evdev_open(struct inode *inode, struct file *file) 310 { 311 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev); 312 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev); 313 struct evdev_client *client; 314 int error; 315 316 client = kzalloc(sizeof(struct evdev_client) + 317 bufsize * sizeof(struct input_event), 318 GFP_KERNEL); 319 if (!client) 320 return -ENOMEM; 321 322 client->bufsize = bufsize; 323 spin_lock_init(&client->buffer_lock); 324 client->evdev = evdev; 325 evdev_attach_client(evdev, client); 326 327 error = evdev_open_device(evdev); 328 if (error) 329 goto err_free_client; 330 331 file->private_data = client; 332 nonseekable_open(inode, file); 333 334 get_device(&evdev->dev); 335 return 0; 336 337 err_free_client: 338 evdev_detach_client(evdev, client); 339 kfree(client); 340 return error; 341 } 342 343 static ssize_t evdev_write(struct file *file, const char __user *buffer, 344 size_t count, loff_t *ppos) 345 { 346 struct evdev_client *client = file->private_data; 347 struct evdev *evdev = client->evdev; 348 struct input_event event; 349 int retval = 0; 350 351 if (count != 0 && count < input_event_size()) 352 return -EINVAL; 353 354 retval = mutex_lock_interruptible(&evdev->mutex); 355 if (retval) 356 return retval; 357 358 if (!evdev->exist) { 359 retval = -ENODEV; 360 goto out; 361 } 362 363 while (retval + input_event_size() <= count) { 364 365 if (input_event_from_user(buffer + retval, &event)) { 366 retval = -EFAULT; 367 goto out; 368 } 369 retval += input_event_size(); 370 371 input_inject_event(&evdev->handle, 372 event.type, event.code, event.value); 373 } 374 375 out: 376 mutex_unlock(&evdev->mutex); 377 return retval; 378 } 379 380 static int evdev_fetch_next_event(struct evdev_client *client, 381 struct input_event *event) 382 { 383 int have_event; 384 385 spin_lock_irq(&client->buffer_lock); 386 387 have_event = client->packet_head != client->tail; 388 if (have_event) { 389 *event = client->buffer[client->tail++]; 390 client->tail &= client->bufsize - 1; 391 } 392 393 spin_unlock_irq(&client->buffer_lock); 394 395 return have_event; 396 } 397 398 static ssize_t evdev_read(struct file *file, char __user *buffer, 399 size_t count, loff_t *ppos) 400 { 401 struct evdev_client *client = file->private_data; 402 struct evdev *evdev = client->evdev; 403 struct input_event event; 404 size_t read = 0; 405 int error; 406 407 if (count != 0 && count < input_event_size()) 408 return -EINVAL; 409 410 for (;;) { 411 if (!evdev->exist) 412 return -ENODEV; 413 414 if (client->packet_head == client->tail && 415 (file->f_flags & O_NONBLOCK)) 416 return -EAGAIN; 417 418 /* 419 * count == 0 is special - no IO is done but we check 420 * for error conditions (see above). 421 */ 422 if (count == 0) 423 break; 424 425 while (read + input_event_size() <= count && 426 evdev_fetch_next_event(client, &event)) { 427 428 if (input_event_to_user(buffer + read, &event)) 429 return -EFAULT; 430 431 read += input_event_size(); 432 } 433 434 if (read) 435 break; 436 437 if (!(file->f_flags & O_NONBLOCK)) { 438 error = wait_event_interruptible(evdev->wait, 439 client->packet_head != client->tail || 440 !evdev->exist); 441 if (error) 442 return error; 443 } 444 } 445 446 return read; 447 } 448 449 /* No kernel lock - fine */ 450 static unsigned int evdev_poll(struct file *file, poll_table *wait) 451 { 452 struct evdev_client *client = file->private_data; 453 struct evdev *evdev = client->evdev; 454 unsigned int mask; 455 456 poll_wait(file, &evdev->wait, wait); 457 458 mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR; 459 if (client->packet_head != client->tail) 460 mask |= POLLIN | POLLRDNORM; 461 462 return mask; 463 } 464 465 #ifdef CONFIG_COMPAT 466 467 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8) 468 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1) 469 470 #ifdef __BIG_ENDIAN 471 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 472 unsigned int maxlen, void __user *p, int compat) 473 { 474 int len, i; 475 476 if (compat) { 477 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t); 478 if (len > maxlen) 479 len = maxlen; 480 481 for (i = 0; i < len / sizeof(compat_long_t); i++) 482 if (copy_to_user((compat_long_t __user *) p + i, 483 (compat_long_t *) bits + 484 i + 1 - ((i % 2) << 1), 485 sizeof(compat_long_t))) 486 return -EFAULT; 487 } else { 488 len = BITS_TO_LONGS(maxbit) * sizeof(long); 489 if (len > maxlen) 490 len = maxlen; 491 492 if (copy_to_user(p, bits, len)) 493 return -EFAULT; 494 } 495 496 return len; 497 } 498 #else 499 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 500 unsigned int maxlen, void __user *p, int compat) 501 { 502 int len = compat ? 503 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) : 504 BITS_TO_LONGS(maxbit) * sizeof(long); 505 506 if (len > maxlen) 507 len = maxlen; 508 509 return copy_to_user(p, bits, len) ? -EFAULT : len; 510 } 511 #endif /* __BIG_ENDIAN */ 512 513 #else 514 515 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 516 unsigned int maxlen, void __user *p, int compat) 517 { 518 int len = BITS_TO_LONGS(maxbit) * sizeof(long); 519 520 if (len > maxlen) 521 len = maxlen; 522 523 return copy_to_user(p, bits, len) ? -EFAULT : len; 524 } 525 526 #endif /* CONFIG_COMPAT */ 527 528 static int str_to_user(const char *str, unsigned int maxlen, void __user *p) 529 { 530 int len; 531 532 if (!str) 533 return -ENOENT; 534 535 len = strlen(str) + 1; 536 if (len > maxlen) 537 len = maxlen; 538 539 return copy_to_user(p, str, len) ? -EFAULT : len; 540 } 541 542 #define OLD_KEY_MAX 0x1ff 543 static int handle_eviocgbit(struct input_dev *dev, 544 unsigned int type, unsigned int size, 545 void __user *p, int compat_mode) 546 { 547 static unsigned long keymax_warn_time; 548 unsigned long *bits; 549 int len; 550 551 switch (type) { 552 553 case 0: bits = dev->evbit; len = EV_MAX; break; 554 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; 555 case EV_REL: bits = dev->relbit; len = REL_MAX; break; 556 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; 557 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; 558 case EV_LED: bits = dev->ledbit; len = LED_MAX; break; 559 case EV_SND: bits = dev->sndbit; len = SND_MAX; break; 560 case EV_FF: bits = dev->ffbit; len = FF_MAX; break; 561 case EV_SW: bits = dev->swbit; len = SW_MAX; break; 562 default: return -EINVAL; 563 } 564 565 /* 566 * Work around bugs in userspace programs that like to do 567 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len' 568 * should be in bytes, not in bits. 569 */ 570 if (type == EV_KEY && size == OLD_KEY_MAX) { 571 len = OLD_KEY_MAX; 572 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000)) 573 pr_warning("(EVIOCGBIT): Suspicious buffer size %u, " 574 "limiting output to %zu bytes. See " 575 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n", 576 OLD_KEY_MAX, 577 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long)); 578 } 579 580 return bits_to_user(bits, len, size, p, compat_mode); 581 } 582 #undef OLD_KEY_MAX 583 584 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p) 585 { 586 struct input_keymap_entry ke = { 587 .len = sizeof(unsigned int), 588 .flags = 0, 589 }; 590 int __user *ip = (int __user *)p; 591 int error; 592 593 /* legacy case */ 594 if (copy_from_user(ke.scancode, p, sizeof(unsigned int))) 595 return -EFAULT; 596 597 error = input_get_keycode(dev, &ke); 598 if (error) 599 return error; 600 601 if (put_user(ke.keycode, ip + 1)) 602 return -EFAULT; 603 604 return 0; 605 } 606 607 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p) 608 { 609 struct input_keymap_entry ke; 610 int error; 611 612 if (copy_from_user(&ke, p, sizeof(ke))) 613 return -EFAULT; 614 615 error = input_get_keycode(dev, &ke); 616 if (error) 617 return error; 618 619 if (copy_to_user(p, &ke, sizeof(ke))) 620 return -EFAULT; 621 622 return 0; 623 } 624 625 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p) 626 { 627 struct input_keymap_entry ke = { 628 .len = sizeof(unsigned int), 629 .flags = 0, 630 }; 631 int __user *ip = (int __user *)p; 632 633 if (copy_from_user(ke.scancode, p, sizeof(unsigned int))) 634 return -EFAULT; 635 636 if (get_user(ke.keycode, ip + 1)) 637 return -EFAULT; 638 639 return input_set_keycode(dev, &ke); 640 } 641 642 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p) 643 { 644 struct input_keymap_entry ke; 645 646 if (copy_from_user(&ke, p, sizeof(ke))) 647 return -EFAULT; 648 649 if (ke.len > sizeof(ke.scancode)) 650 return -EINVAL; 651 652 return input_set_keycode(dev, &ke); 653 } 654 655 static int evdev_handle_mt_request(struct input_dev *dev, 656 unsigned int size, 657 int __user *ip) 658 { 659 const struct input_mt *mt = dev->mt; 660 unsigned int code; 661 int max_slots; 662 int i; 663 664 if (get_user(code, &ip[0])) 665 return -EFAULT; 666 if (!mt || !input_is_mt_value(code)) 667 return -EINVAL; 668 669 max_slots = (size - sizeof(__u32)) / sizeof(__s32); 670 for (i = 0; i < mt->num_slots && i < max_slots; i++) { 671 int value = input_mt_get_value(&mt->slots[i], code); 672 if (put_user(value, &ip[1 + i])) 673 return -EFAULT; 674 } 675 676 return 0; 677 } 678 679 static long evdev_do_ioctl(struct file *file, unsigned int cmd, 680 void __user *p, int compat_mode) 681 { 682 struct evdev_client *client = file->private_data; 683 struct evdev *evdev = client->evdev; 684 struct input_dev *dev = evdev->handle.dev; 685 struct input_absinfo abs; 686 struct ff_effect effect; 687 int __user *ip = (int __user *)p; 688 unsigned int i, t, u, v; 689 unsigned int size; 690 int error; 691 692 /* First we check for fixed-length commands */ 693 switch (cmd) { 694 695 case EVIOCGVERSION: 696 return put_user(EV_VERSION, ip); 697 698 case EVIOCGID: 699 if (copy_to_user(p, &dev->id, sizeof(struct input_id))) 700 return -EFAULT; 701 return 0; 702 703 case EVIOCGREP: 704 if (!test_bit(EV_REP, dev->evbit)) 705 return -ENOSYS; 706 if (put_user(dev->rep[REP_DELAY], ip)) 707 return -EFAULT; 708 if (put_user(dev->rep[REP_PERIOD], ip + 1)) 709 return -EFAULT; 710 return 0; 711 712 case EVIOCSREP: 713 if (!test_bit(EV_REP, dev->evbit)) 714 return -ENOSYS; 715 if (get_user(u, ip)) 716 return -EFAULT; 717 if (get_user(v, ip + 1)) 718 return -EFAULT; 719 720 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); 721 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); 722 723 return 0; 724 725 case EVIOCRMFF: 726 return input_ff_erase(dev, (int)(unsigned long) p, file); 727 728 case EVIOCGEFFECTS: 729 i = test_bit(EV_FF, dev->evbit) ? 730 dev->ff->max_effects : 0; 731 if (put_user(i, ip)) 732 return -EFAULT; 733 return 0; 734 735 case EVIOCGRAB: 736 if (p) 737 return evdev_grab(evdev, client); 738 else 739 return evdev_ungrab(evdev, client); 740 741 case EVIOCSCLOCKID: 742 if (copy_from_user(&i, p, sizeof(unsigned int))) 743 return -EFAULT; 744 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME) 745 return -EINVAL; 746 client->clkid = i; 747 return 0; 748 749 case EVIOCGKEYCODE: 750 return evdev_handle_get_keycode(dev, p); 751 752 case EVIOCSKEYCODE: 753 return evdev_handle_set_keycode(dev, p); 754 755 case EVIOCGKEYCODE_V2: 756 return evdev_handle_get_keycode_v2(dev, p); 757 758 case EVIOCSKEYCODE_V2: 759 return evdev_handle_set_keycode_v2(dev, p); 760 } 761 762 size = _IOC_SIZE(cmd); 763 764 /* Now check variable-length commands */ 765 #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT)) 766 switch (EVIOC_MASK_SIZE(cmd)) { 767 768 case EVIOCGPROP(0): 769 return bits_to_user(dev->propbit, INPUT_PROP_MAX, 770 size, p, compat_mode); 771 772 case EVIOCGMTSLOTS(0): 773 return evdev_handle_mt_request(dev, size, ip); 774 775 case EVIOCGKEY(0): 776 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode); 777 778 case EVIOCGLED(0): 779 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode); 780 781 case EVIOCGSND(0): 782 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode); 783 784 case EVIOCGSW(0): 785 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode); 786 787 case EVIOCGNAME(0): 788 return str_to_user(dev->name, size, p); 789 790 case EVIOCGPHYS(0): 791 return str_to_user(dev->phys, size, p); 792 793 case EVIOCGUNIQ(0): 794 return str_to_user(dev->uniq, size, p); 795 796 case EVIOC_MASK_SIZE(EVIOCSFF): 797 if (input_ff_effect_from_user(p, size, &effect)) 798 return -EFAULT; 799 800 error = input_ff_upload(dev, &effect, file); 801 802 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) 803 return -EFAULT; 804 805 return error; 806 } 807 808 /* Multi-number variable-length handlers */ 809 if (_IOC_TYPE(cmd) != 'E') 810 return -EINVAL; 811 812 if (_IOC_DIR(cmd) == _IOC_READ) { 813 814 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) 815 return handle_eviocgbit(dev, 816 _IOC_NR(cmd) & EV_MAX, size, 817 p, compat_mode); 818 819 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { 820 821 if (!dev->absinfo) 822 return -EINVAL; 823 824 t = _IOC_NR(cmd) & ABS_MAX; 825 abs = dev->absinfo[t]; 826 827 if (copy_to_user(p, &abs, min_t(size_t, 828 size, sizeof(struct input_absinfo)))) 829 return -EFAULT; 830 831 return 0; 832 } 833 } 834 835 if (_IOC_DIR(cmd) == _IOC_WRITE) { 836 837 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { 838 839 if (!dev->absinfo) 840 return -EINVAL; 841 842 t = _IOC_NR(cmd) & ABS_MAX; 843 844 if (copy_from_user(&abs, p, min_t(size_t, 845 size, sizeof(struct input_absinfo)))) 846 return -EFAULT; 847 848 if (size < sizeof(struct input_absinfo)) 849 abs.resolution = 0; 850 851 /* We can't change number of reserved MT slots */ 852 if (t == ABS_MT_SLOT) 853 return -EINVAL; 854 855 /* 856 * Take event lock to ensure that we are not 857 * changing device parameters in the middle 858 * of event. 859 */ 860 spin_lock_irq(&dev->event_lock); 861 dev->absinfo[t] = abs; 862 spin_unlock_irq(&dev->event_lock); 863 864 return 0; 865 } 866 } 867 868 return -EINVAL; 869 } 870 871 static long evdev_ioctl_handler(struct file *file, unsigned int cmd, 872 void __user *p, int compat_mode) 873 { 874 struct evdev_client *client = file->private_data; 875 struct evdev *evdev = client->evdev; 876 int retval; 877 878 retval = mutex_lock_interruptible(&evdev->mutex); 879 if (retval) 880 return retval; 881 882 if (!evdev->exist) { 883 retval = -ENODEV; 884 goto out; 885 } 886 887 retval = evdev_do_ioctl(file, cmd, p, compat_mode); 888 889 out: 890 mutex_unlock(&evdev->mutex); 891 return retval; 892 } 893 894 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 895 { 896 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0); 897 } 898 899 #ifdef CONFIG_COMPAT 900 static long evdev_ioctl_compat(struct file *file, 901 unsigned int cmd, unsigned long arg) 902 { 903 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1); 904 } 905 #endif 906 907 static const struct file_operations evdev_fops = { 908 .owner = THIS_MODULE, 909 .read = evdev_read, 910 .write = evdev_write, 911 .poll = evdev_poll, 912 .open = evdev_open, 913 .release = evdev_release, 914 .unlocked_ioctl = evdev_ioctl, 915 #ifdef CONFIG_COMPAT 916 .compat_ioctl = evdev_ioctl_compat, 917 #endif 918 .fasync = evdev_fasync, 919 .flush = evdev_flush, 920 .llseek = no_llseek, 921 }; 922 923 /* 924 * Mark device non-existent. This disables writes, ioctls and 925 * prevents new users from opening the device. Already posted 926 * blocking reads will stay, however new ones will fail. 927 */ 928 static void evdev_mark_dead(struct evdev *evdev) 929 { 930 mutex_lock(&evdev->mutex); 931 evdev->exist = false; 932 mutex_unlock(&evdev->mutex); 933 } 934 935 static void evdev_cleanup(struct evdev *evdev) 936 { 937 struct input_handle *handle = &evdev->handle; 938 939 evdev_mark_dead(evdev); 940 evdev_hangup(evdev); 941 942 cdev_del(&evdev->cdev); 943 944 /* evdev is marked dead so no one else accesses evdev->open */ 945 if (evdev->open) { 946 input_flush_device(handle, NULL); 947 input_close_device(handle); 948 } 949 } 950 951 /* 952 * Create new evdev device. Note that input core serializes calls 953 * to connect and disconnect. 954 */ 955 static int evdev_connect(struct input_handler *handler, struct input_dev *dev, 956 const struct input_device_id *id) 957 { 958 struct evdev *evdev; 959 int minor; 960 int dev_no; 961 int error; 962 963 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true); 964 if (minor < 0) { 965 error = minor; 966 pr_err("failed to reserve new minor: %d\n", error); 967 return error; 968 } 969 970 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL); 971 if (!evdev) { 972 error = -ENOMEM; 973 goto err_free_minor; 974 } 975 976 INIT_LIST_HEAD(&evdev->client_list); 977 spin_lock_init(&evdev->client_lock); 978 mutex_init(&evdev->mutex); 979 init_waitqueue_head(&evdev->wait); 980 evdev->exist = true; 981 982 dev_no = minor; 983 /* Normalize device number if it falls into legacy range */ 984 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS) 985 dev_no -= EVDEV_MINOR_BASE; 986 dev_set_name(&evdev->dev, "event%d", dev_no); 987 988 evdev->handle.dev = input_get_device(dev); 989 evdev->handle.name = dev_name(&evdev->dev); 990 evdev->handle.handler = handler; 991 evdev->handle.private = evdev; 992 993 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor); 994 evdev->dev.class = &input_class; 995 evdev->dev.parent = &dev->dev; 996 evdev->dev.release = evdev_free; 997 device_initialize(&evdev->dev); 998 999 error = input_register_handle(&evdev->handle); 1000 if (error) 1001 goto err_free_evdev; 1002 1003 cdev_init(&evdev->cdev, &evdev_fops); 1004 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1); 1005 if (error) 1006 goto err_unregister_handle; 1007 1008 error = device_add(&evdev->dev); 1009 if (error) 1010 goto err_cleanup_evdev; 1011 1012 return 0; 1013 1014 err_cleanup_evdev: 1015 evdev_cleanup(evdev); 1016 err_unregister_handle: 1017 input_unregister_handle(&evdev->handle); 1018 err_free_evdev: 1019 put_device(&evdev->dev); 1020 err_free_minor: 1021 input_free_minor(minor); 1022 return error; 1023 } 1024 1025 static void evdev_disconnect(struct input_handle *handle) 1026 { 1027 struct evdev *evdev = handle->private; 1028 1029 device_del(&evdev->dev); 1030 evdev_cleanup(evdev); 1031 input_free_minor(MINOR(evdev->dev.devt)); 1032 input_unregister_handle(handle); 1033 put_device(&evdev->dev); 1034 } 1035 1036 static const struct input_device_id evdev_ids[] = { 1037 { .driver_info = 1 }, /* Matches all devices */ 1038 { }, /* Terminating zero entry */ 1039 }; 1040 1041 MODULE_DEVICE_TABLE(input, evdev_ids); 1042 1043 static struct input_handler evdev_handler = { 1044 .event = evdev_event, 1045 .events = evdev_events, 1046 .connect = evdev_connect, 1047 .disconnect = evdev_disconnect, 1048 .legacy_minors = true, 1049 .minor = EVDEV_MINOR_BASE, 1050 .name = "evdev", 1051 .id_table = evdev_ids, 1052 }; 1053 1054 static int __init evdev_init(void) 1055 { 1056 return input_register_handler(&evdev_handler); 1057 } 1058 1059 static void __exit evdev_exit(void) 1060 { 1061 input_unregister_handler(&evdev_handler); 1062 } 1063 1064 module_init(evdev_init); 1065 module_exit(evdev_exit); 1066 1067 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 1068 MODULE_DESCRIPTION("Input driver event char devices"); 1069 MODULE_LICENSE("GPL"); 1070