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); 295 296 return 0; 297 } 298 299 static unsigned int evdev_compute_buffer_size(struct input_dev *dev) 300 { 301 unsigned int n_events = 302 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS, 303 EVDEV_MIN_BUFFER_SIZE); 304 305 return roundup_pow_of_two(n_events); 306 } 307 308 static int evdev_open(struct inode *inode, struct file *file) 309 { 310 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev); 311 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev); 312 struct evdev_client *client; 313 int error; 314 315 client = kzalloc(sizeof(struct evdev_client) + 316 bufsize * sizeof(struct input_event), 317 GFP_KERNEL); 318 if (!client) 319 return -ENOMEM; 320 321 client->bufsize = bufsize; 322 spin_lock_init(&client->buffer_lock); 323 client->evdev = evdev; 324 evdev_attach_client(evdev, client); 325 326 error = evdev_open_device(evdev); 327 if (error) 328 goto err_free_client; 329 330 file->private_data = client; 331 nonseekable_open(inode, file); 332 333 return 0; 334 335 err_free_client: 336 evdev_detach_client(evdev, client); 337 kfree(client); 338 return error; 339 } 340 341 static ssize_t evdev_write(struct file *file, const char __user *buffer, 342 size_t count, loff_t *ppos) 343 { 344 struct evdev_client *client = file->private_data; 345 struct evdev *evdev = client->evdev; 346 struct input_event event; 347 int retval = 0; 348 349 if (count != 0 && count < input_event_size()) 350 return -EINVAL; 351 352 retval = mutex_lock_interruptible(&evdev->mutex); 353 if (retval) 354 return retval; 355 356 if (!evdev->exist) { 357 retval = -ENODEV; 358 goto out; 359 } 360 361 while (retval + input_event_size() <= count) { 362 363 if (input_event_from_user(buffer + retval, &event)) { 364 retval = -EFAULT; 365 goto out; 366 } 367 retval += input_event_size(); 368 369 input_inject_event(&evdev->handle, 370 event.type, event.code, event.value); 371 } 372 373 out: 374 mutex_unlock(&evdev->mutex); 375 return retval; 376 } 377 378 static int evdev_fetch_next_event(struct evdev_client *client, 379 struct input_event *event) 380 { 381 int have_event; 382 383 spin_lock_irq(&client->buffer_lock); 384 385 have_event = client->packet_head != client->tail; 386 if (have_event) { 387 *event = client->buffer[client->tail++]; 388 client->tail &= client->bufsize - 1; 389 } 390 391 spin_unlock_irq(&client->buffer_lock); 392 393 return have_event; 394 } 395 396 static ssize_t evdev_read(struct file *file, char __user *buffer, 397 size_t count, loff_t *ppos) 398 { 399 struct evdev_client *client = file->private_data; 400 struct evdev *evdev = client->evdev; 401 struct input_event event; 402 size_t read = 0; 403 int error; 404 405 if (count != 0 && count < input_event_size()) 406 return -EINVAL; 407 408 for (;;) { 409 if (!evdev->exist) 410 return -ENODEV; 411 412 if (client->packet_head == client->tail && 413 (file->f_flags & O_NONBLOCK)) 414 return -EAGAIN; 415 416 /* 417 * count == 0 is special - no IO is done but we check 418 * for error conditions (see above). 419 */ 420 if (count == 0) 421 break; 422 423 while (read + input_event_size() <= count && 424 evdev_fetch_next_event(client, &event)) { 425 426 if (input_event_to_user(buffer + read, &event)) 427 return -EFAULT; 428 429 read += input_event_size(); 430 } 431 432 if (read) 433 break; 434 435 if (!(file->f_flags & O_NONBLOCK)) { 436 error = wait_event_interruptible(evdev->wait, 437 client->packet_head != client->tail || 438 !evdev->exist); 439 if (error) 440 return error; 441 } 442 } 443 444 return read; 445 } 446 447 /* No kernel lock - fine */ 448 static unsigned int evdev_poll(struct file *file, poll_table *wait) 449 { 450 struct evdev_client *client = file->private_data; 451 struct evdev *evdev = client->evdev; 452 unsigned int mask; 453 454 poll_wait(file, &evdev->wait, wait); 455 456 mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR; 457 if (client->packet_head != client->tail) 458 mask |= POLLIN | POLLRDNORM; 459 460 return mask; 461 } 462 463 #ifdef CONFIG_COMPAT 464 465 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8) 466 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1) 467 468 #ifdef __BIG_ENDIAN 469 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 470 unsigned int maxlen, void __user *p, int compat) 471 { 472 int len, i; 473 474 if (compat) { 475 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t); 476 if (len > maxlen) 477 len = maxlen; 478 479 for (i = 0; i < len / sizeof(compat_long_t); i++) 480 if (copy_to_user((compat_long_t __user *) p + i, 481 (compat_long_t *) bits + 482 i + 1 - ((i % 2) << 1), 483 sizeof(compat_long_t))) 484 return -EFAULT; 485 } else { 486 len = BITS_TO_LONGS(maxbit) * sizeof(long); 487 if (len > maxlen) 488 len = maxlen; 489 490 if (copy_to_user(p, bits, len)) 491 return -EFAULT; 492 } 493 494 return len; 495 } 496 #else 497 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 498 unsigned int maxlen, void __user *p, int compat) 499 { 500 int len = compat ? 501 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) : 502 BITS_TO_LONGS(maxbit) * sizeof(long); 503 504 if (len > maxlen) 505 len = maxlen; 506 507 return copy_to_user(p, bits, len) ? -EFAULT : len; 508 } 509 #endif /* __BIG_ENDIAN */ 510 511 #else 512 513 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 514 unsigned int maxlen, void __user *p, int compat) 515 { 516 int len = BITS_TO_LONGS(maxbit) * sizeof(long); 517 518 if (len > maxlen) 519 len = maxlen; 520 521 return copy_to_user(p, bits, len) ? -EFAULT : len; 522 } 523 524 #endif /* CONFIG_COMPAT */ 525 526 static int str_to_user(const char *str, unsigned int maxlen, void __user *p) 527 { 528 int len; 529 530 if (!str) 531 return -ENOENT; 532 533 len = strlen(str) + 1; 534 if (len > maxlen) 535 len = maxlen; 536 537 return copy_to_user(p, str, len) ? -EFAULT : len; 538 } 539 540 #define OLD_KEY_MAX 0x1ff 541 static int handle_eviocgbit(struct input_dev *dev, 542 unsigned int type, unsigned int size, 543 void __user *p, int compat_mode) 544 { 545 static unsigned long keymax_warn_time; 546 unsigned long *bits; 547 int len; 548 549 switch (type) { 550 551 case 0: bits = dev->evbit; len = EV_MAX; break; 552 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; 553 case EV_REL: bits = dev->relbit; len = REL_MAX; break; 554 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; 555 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; 556 case EV_LED: bits = dev->ledbit; len = LED_MAX; break; 557 case EV_SND: bits = dev->sndbit; len = SND_MAX; break; 558 case EV_FF: bits = dev->ffbit; len = FF_MAX; break; 559 case EV_SW: bits = dev->swbit; len = SW_MAX; break; 560 default: return -EINVAL; 561 } 562 563 /* 564 * Work around bugs in userspace programs that like to do 565 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len' 566 * should be in bytes, not in bits. 567 */ 568 if (type == EV_KEY && size == OLD_KEY_MAX) { 569 len = OLD_KEY_MAX; 570 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000)) 571 pr_warning("(EVIOCGBIT): Suspicious buffer size %u, " 572 "limiting output to %zu bytes. See " 573 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n", 574 OLD_KEY_MAX, 575 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long)); 576 } 577 578 return bits_to_user(bits, len, size, p, compat_mode); 579 } 580 #undef OLD_KEY_MAX 581 582 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p) 583 { 584 struct input_keymap_entry ke = { 585 .len = sizeof(unsigned int), 586 .flags = 0, 587 }; 588 int __user *ip = (int __user *)p; 589 int error; 590 591 /* legacy case */ 592 if (copy_from_user(ke.scancode, p, sizeof(unsigned int))) 593 return -EFAULT; 594 595 error = input_get_keycode(dev, &ke); 596 if (error) 597 return error; 598 599 if (put_user(ke.keycode, ip + 1)) 600 return -EFAULT; 601 602 return 0; 603 } 604 605 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p) 606 { 607 struct input_keymap_entry ke; 608 int error; 609 610 if (copy_from_user(&ke, p, sizeof(ke))) 611 return -EFAULT; 612 613 error = input_get_keycode(dev, &ke); 614 if (error) 615 return error; 616 617 if (copy_to_user(p, &ke, sizeof(ke))) 618 return -EFAULT; 619 620 return 0; 621 } 622 623 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p) 624 { 625 struct input_keymap_entry ke = { 626 .len = sizeof(unsigned int), 627 .flags = 0, 628 }; 629 int __user *ip = (int __user *)p; 630 631 if (copy_from_user(ke.scancode, p, sizeof(unsigned int))) 632 return -EFAULT; 633 634 if (get_user(ke.keycode, ip + 1)) 635 return -EFAULT; 636 637 return input_set_keycode(dev, &ke); 638 } 639 640 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p) 641 { 642 struct input_keymap_entry ke; 643 644 if (copy_from_user(&ke, p, sizeof(ke))) 645 return -EFAULT; 646 647 if (ke.len > sizeof(ke.scancode)) 648 return -EINVAL; 649 650 return input_set_keycode(dev, &ke); 651 } 652 653 static int evdev_handle_mt_request(struct input_dev *dev, 654 unsigned int size, 655 int __user *ip) 656 { 657 const struct input_mt *mt = dev->mt; 658 unsigned int code; 659 int max_slots; 660 int i; 661 662 if (get_user(code, &ip[0])) 663 return -EFAULT; 664 if (!mt || !input_is_mt_value(code)) 665 return -EINVAL; 666 667 max_slots = (size - sizeof(__u32)) / sizeof(__s32); 668 for (i = 0; i < mt->num_slots && i < max_slots; i++) { 669 int value = input_mt_get_value(&mt->slots[i], code); 670 if (put_user(value, &ip[1 + i])) 671 return -EFAULT; 672 } 673 674 return 0; 675 } 676 677 static long evdev_do_ioctl(struct file *file, unsigned int cmd, 678 void __user *p, int compat_mode) 679 { 680 struct evdev_client *client = file->private_data; 681 struct evdev *evdev = client->evdev; 682 struct input_dev *dev = evdev->handle.dev; 683 struct input_absinfo abs; 684 struct ff_effect effect; 685 int __user *ip = (int __user *)p; 686 unsigned int i, t, u, v; 687 unsigned int size; 688 int error; 689 690 /* First we check for fixed-length commands */ 691 switch (cmd) { 692 693 case EVIOCGVERSION: 694 return put_user(EV_VERSION, ip); 695 696 case EVIOCGID: 697 if (copy_to_user(p, &dev->id, sizeof(struct input_id))) 698 return -EFAULT; 699 return 0; 700 701 case EVIOCGREP: 702 if (!test_bit(EV_REP, dev->evbit)) 703 return -ENOSYS; 704 if (put_user(dev->rep[REP_DELAY], ip)) 705 return -EFAULT; 706 if (put_user(dev->rep[REP_PERIOD], ip + 1)) 707 return -EFAULT; 708 return 0; 709 710 case EVIOCSREP: 711 if (!test_bit(EV_REP, dev->evbit)) 712 return -ENOSYS; 713 if (get_user(u, ip)) 714 return -EFAULT; 715 if (get_user(v, ip + 1)) 716 return -EFAULT; 717 718 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); 719 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); 720 721 return 0; 722 723 case EVIOCRMFF: 724 return input_ff_erase(dev, (int)(unsigned long) p, file); 725 726 case EVIOCGEFFECTS: 727 i = test_bit(EV_FF, dev->evbit) ? 728 dev->ff->max_effects : 0; 729 if (put_user(i, ip)) 730 return -EFAULT; 731 return 0; 732 733 case EVIOCGRAB: 734 if (p) 735 return evdev_grab(evdev, client); 736 else 737 return evdev_ungrab(evdev, client); 738 739 case EVIOCSCLOCKID: 740 if (copy_from_user(&i, p, sizeof(unsigned int))) 741 return -EFAULT; 742 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME) 743 return -EINVAL; 744 client->clkid = i; 745 return 0; 746 747 case EVIOCGKEYCODE: 748 return evdev_handle_get_keycode(dev, p); 749 750 case EVIOCSKEYCODE: 751 return evdev_handle_set_keycode(dev, p); 752 753 case EVIOCGKEYCODE_V2: 754 return evdev_handle_get_keycode_v2(dev, p); 755 756 case EVIOCSKEYCODE_V2: 757 return evdev_handle_set_keycode_v2(dev, p); 758 } 759 760 size = _IOC_SIZE(cmd); 761 762 /* Now check variable-length commands */ 763 #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT)) 764 switch (EVIOC_MASK_SIZE(cmd)) { 765 766 case EVIOCGPROP(0): 767 return bits_to_user(dev->propbit, INPUT_PROP_MAX, 768 size, p, compat_mode); 769 770 case EVIOCGMTSLOTS(0): 771 return evdev_handle_mt_request(dev, size, ip); 772 773 case EVIOCGKEY(0): 774 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode); 775 776 case EVIOCGLED(0): 777 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode); 778 779 case EVIOCGSND(0): 780 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode); 781 782 case EVIOCGSW(0): 783 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode); 784 785 case EVIOCGNAME(0): 786 return str_to_user(dev->name, size, p); 787 788 case EVIOCGPHYS(0): 789 return str_to_user(dev->phys, size, p); 790 791 case EVIOCGUNIQ(0): 792 return str_to_user(dev->uniq, size, p); 793 794 case EVIOC_MASK_SIZE(EVIOCSFF): 795 if (input_ff_effect_from_user(p, size, &effect)) 796 return -EFAULT; 797 798 error = input_ff_upload(dev, &effect, file); 799 800 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) 801 return -EFAULT; 802 803 return error; 804 } 805 806 /* Multi-number variable-length handlers */ 807 if (_IOC_TYPE(cmd) != 'E') 808 return -EINVAL; 809 810 if (_IOC_DIR(cmd) == _IOC_READ) { 811 812 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) 813 return handle_eviocgbit(dev, 814 _IOC_NR(cmd) & EV_MAX, size, 815 p, compat_mode); 816 817 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { 818 819 if (!dev->absinfo) 820 return -EINVAL; 821 822 t = _IOC_NR(cmd) & ABS_MAX; 823 abs = dev->absinfo[t]; 824 825 if (copy_to_user(p, &abs, min_t(size_t, 826 size, sizeof(struct input_absinfo)))) 827 return -EFAULT; 828 829 return 0; 830 } 831 } 832 833 if (_IOC_DIR(cmd) == _IOC_WRITE) { 834 835 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { 836 837 if (!dev->absinfo) 838 return -EINVAL; 839 840 t = _IOC_NR(cmd) & ABS_MAX; 841 842 if (copy_from_user(&abs, p, min_t(size_t, 843 size, sizeof(struct input_absinfo)))) 844 return -EFAULT; 845 846 if (size < sizeof(struct input_absinfo)) 847 abs.resolution = 0; 848 849 /* We can't change number of reserved MT slots */ 850 if (t == ABS_MT_SLOT) 851 return -EINVAL; 852 853 /* 854 * Take event lock to ensure that we are not 855 * changing device parameters in the middle 856 * of event. 857 */ 858 spin_lock_irq(&dev->event_lock); 859 dev->absinfo[t] = abs; 860 spin_unlock_irq(&dev->event_lock); 861 862 return 0; 863 } 864 } 865 866 return -EINVAL; 867 } 868 869 static long evdev_ioctl_handler(struct file *file, unsigned int cmd, 870 void __user *p, int compat_mode) 871 { 872 struct evdev_client *client = file->private_data; 873 struct evdev *evdev = client->evdev; 874 int retval; 875 876 retval = mutex_lock_interruptible(&evdev->mutex); 877 if (retval) 878 return retval; 879 880 if (!evdev->exist) { 881 retval = -ENODEV; 882 goto out; 883 } 884 885 retval = evdev_do_ioctl(file, cmd, p, compat_mode); 886 887 out: 888 mutex_unlock(&evdev->mutex); 889 return retval; 890 } 891 892 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 893 { 894 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0); 895 } 896 897 #ifdef CONFIG_COMPAT 898 static long evdev_ioctl_compat(struct file *file, 899 unsigned int cmd, unsigned long arg) 900 { 901 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1); 902 } 903 #endif 904 905 static const struct file_operations evdev_fops = { 906 .owner = THIS_MODULE, 907 .read = evdev_read, 908 .write = evdev_write, 909 .poll = evdev_poll, 910 .open = evdev_open, 911 .release = evdev_release, 912 .unlocked_ioctl = evdev_ioctl, 913 #ifdef CONFIG_COMPAT 914 .compat_ioctl = evdev_ioctl_compat, 915 #endif 916 .fasync = evdev_fasync, 917 .flush = evdev_flush, 918 .llseek = no_llseek, 919 }; 920 921 /* 922 * Mark device non-existent. This disables writes, ioctls and 923 * prevents new users from opening the device. Already posted 924 * blocking reads will stay, however new ones will fail. 925 */ 926 static void evdev_mark_dead(struct evdev *evdev) 927 { 928 mutex_lock(&evdev->mutex); 929 evdev->exist = false; 930 mutex_unlock(&evdev->mutex); 931 } 932 933 static void evdev_cleanup(struct evdev *evdev) 934 { 935 struct input_handle *handle = &evdev->handle; 936 937 evdev_mark_dead(evdev); 938 evdev_hangup(evdev); 939 940 cdev_del(&evdev->cdev); 941 942 /* evdev is marked dead so no one else accesses evdev->open */ 943 if (evdev->open) { 944 input_flush_device(handle, NULL); 945 input_close_device(handle); 946 } 947 } 948 949 /* 950 * Create new evdev device. Note that input core serializes calls 951 * to connect and disconnect. 952 */ 953 static int evdev_connect(struct input_handler *handler, struct input_dev *dev, 954 const struct input_device_id *id) 955 { 956 struct evdev *evdev; 957 int minor; 958 int dev_no; 959 int error; 960 961 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true); 962 if (minor < 0) { 963 error = minor; 964 pr_err("failed to reserve new minor: %d\n", error); 965 return error; 966 } 967 968 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL); 969 if (!evdev) { 970 error = -ENOMEM; 971 goto err_free_minor; 972 } 973 974 INIT_LIST_HEAD(&evdev->client_list); 975 spin_lock_init(&evdev->client_lock); 976 mutex_init(&evdev->mutex); 977 init_waitqueue_head(&evdev->wait); 978 evdev->exist = true; 979 980 dev_no = minor; 981 /* Normalize device number if it falls into legacy range */ 982 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS) 983 dev_no -= EVDEV_MINOR_BASE; 984 dev_set_name(&evdev->dev, "event%d", dev_no); 985 986 evdev->handle.dev = input_get_device(dev); 987 evdev->handle.name = dev_name(&evdev->dev); 988 evdev->handle.handler = handler; 989 evdev->handle.private = evdev; 990 991 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor); 992 evdev->dev.class = &input_class; 993 evdev->dev.parent = &dev->dev; 994 evdev->dev.release = evdev_free; 995 device_initialize(&evdev->dev); 996 997 error = input_register_handle(&evdev->handle); 998 if (error) 999 goto err_free_evdev; 1000 1001 cdev_init(&evdev->cdev, &evdev_fops); 1002 evdev->cdev.kobj.parent = &evdev->dev.kobj; 1003 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1); 1004 if (error) 1005 goto err_unregister_handle; 1006 1007 error = device_add(&evdev->dev); 1008 if (error) 1009 goto err_cleanup_evdev; 1010 1011 return 0; 1012 1013 err_cleanup_evdev: 1014 evdev_cleanup(evdev); 1015 err_unregister_handle: 1016 input_unregister_handle(&evdev->handle); 1017 err_free_evdev: 1018 put_device(&evdev->dev); 1019 err_free_minor: 1020 input_free_minor(minor); 1021 return error; 1022 } 1023 1024 static void evdev_disconnect(struct input_handle *handle) 1025 { 1026 struct evdev *evdev = handle->private; 1027 1028 device_del(&evdev->dev); 1029 evdev_cleanup(evdev); 1030 input_free_minor(MINOR(evdev->dev.devt)); 1031 input_unregister_handle(handle); 1032 put_device(&evdev->dev); 1033 } 1034 1035 static const struct input_device_id evdev_ids[] = { 1036 { .driver_info = 1 }, /* Matches all devices */ 1037 { }, /* Terminating zero entry */ 1038 }; 1039 1040 MODULE_DEVICE_TABLE(input, evdev_ids); 1041 1042 static struct input_handler evdev_handler = { 1043 .event = evdev_event, 1044 .events = evdev_events, 1045 .connect = evdev_connect, 1046 .disconnect = evdev_disconnect, 1047 .legacy_minors = true, 1048 .minor = EVDEV_MINOR_BASE, 1049 .name = "evdev", 1050 .id_table = evdev_ids, 1051 }; 1052 1053 static int __init evdev_init(void) 1054 { 1055 return input_register_handler(&evdev_handler); 1056 } 1057 1058 static void __exit evdev_exit(void) 1059 { 1060 input_unregister_handler(&evdev_handler); 1061 } 1062 1063 module_init(evdev_init); 1064 module_exit(evdev_exit); 1065 1066 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 1067 MODULE_DESCRIPTION("Input driver event char devices"); 1068 MODULE_LICENSE("GPL"); 1069