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