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/vmalloc.h> 22 #include <linux/mm.h> 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/input/mt.h> 26 #include <linux/major.h> 27 #include <linux/device.h> 28 #include <linux/cdev.h> 29 #include "input-compat.h" 30 31 enum evdev_clock_type { 32 EV_CLK_REAL = 0, 33 EV_CLK_MONO, 34 EV_CLK_BOOT, 35 EV_CLK_MAX 36 }; 37 38 struct evdev { 39 int open; 40 struct input_handle handle; 41 wait_queue_head_t wait; 42 struct evdev_client __rcu *grab; 43 struct list_head client_list; 44 spinlock_t client_lock; /* protects client_list */ 45 struct mutex mutex; 46 struct device dev; 47 struct cdev cdev; 48 bool exist; 49 }; 50 51 struct evdev_client { 52 unsigned int head; 53 unsigned int tail; 54 unsigned int packet_head; /* [future] position of the first element of next packet */ 55 spinlock_t buffer_lock; /* protects access to buffer, head and tail */ 56 struct fasync_struct *fasync; 57 struct evdev *evdev; 58 struct list_head node; 59 int clk_type; 60 bool revoked; 61 unsigned int bufsize; 62 struct input_event buffer[]; 63 }; 64 65 /* flush queued events of type @type, caller must hold client->buffer_lock */ 66 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type) 67 { 68 unsigned int i, head, num; 69 unsigned int mask = client->bufsize - 1; 70 bool is_report; 71 struct input_event *ev; 72 73 BUG_ON(type == EV_SYN); 74 75 head = client->tail; 76 client->packet_head = client->tail; 77 78 /* init to 1 so a leading SYN_REPORT will not be dropped */ 79 num = 1; 80 81 for (i = client->tail; i != client->head; i = (i + 1) & mask) { 82 ev = &client->buffer[i]; 83 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT; 84 85 if (ev->type == type) { 86 /* drop matched entry */ 87 continue; 88 } else if (is_report && !num) { 89 /* drop empty SYN_REPORT groups */ 90 continue; 91 } else if (head != i) { 92 /* move entry to fill the gap */ 93 client->buffer[head].time = ev->time; 94 client->buffer[head].type = ev->type; 95 client->buffer[head].code = ev->code; 96 client->buffer[head].value = ev->value; 97 } 98 99 num++; 100 head = (head + 1) & mask; 101 102 if (is_report) { 103 num = 0; 104 client->packet_head = head; 105 } 106 } 107 108 client->head = head; 109 } 110 111 static void __evdev_queue_syn_dropped(struct evdev_client *client) 112 { 113 struct input_event ev; 114 ktime_t time; 115 116 time = client->clk_type == EV_CLK_REAL ? 117 ktime_get_real() : 118 client->clk_type == EV_CLK_MONO ? 119 ktime_get() : 120 ktime_get_boottime(); 121 122 ev.time = ktime_to_timeval(time); 123 ev.type = EV_SYN; 124 ev.code = SYN_DROPPED; 125 ev.value = 0; 126 127 client->buffer[client->head++] = ev; 128 client->head &= client->bufsize - 1; 129 130 if (unlikely(client->head == client->tail)) { 131 /* drop queue but keep our SYN_DROPPED event */ 132 client->tail = (client->head - 1) & (client->bufsize - 1); 133 client->packet_head = client->tail; 134 } 135 } 136 137 static void evdev_queue_syn_dropped(struct evdev_client *client) 138 { 139 unsigned long flags; 140 141 spin_lock_irqsave(&client->buffer_lock, flags); 142 __evdev_queue_syn_dropped(client); 143 spin_unlock_irqrestore(&client->buffer_lock, flags); 144 } 145 146 static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid) 147 { 148 unsigned long flags; 149 150 if (client->clk_type == clkid) 151 return 0; 152 153 switch (clkid) { 154 155 case CLOCK_REALTIME: 156 client->clk_type = EV_CLK_REAL; 157 break; 158 case CLOCK_MONOTONIC: 159 client->clk_type = EV_CLK_MONO; 160 break; 161 case CLOCK_BOOTTIME: 162 client->clk_type = EV_CLK_BOOT; 163 break; 164 default: 165 return -EINVAL; 166 } 167 168 /* 169 * Flush pending events and queue SYN_DROPPED event, 170 * but only if the queue is not empty. 171 */ 172 spin_lock_irqsave(&client->buffer_lock, flags); 173 174 if (client->head != client->tail) { 175 client->packet_head = client->head = client->tail; 176 __evdev_queue_syn_dropped(client); 177 } 178 179 spin_unlock_irqrestore(&client->buffer_lock, flags); 180 181 return 0; 182 } 183 184 static void __pass_event(struct evdev_client *client, 185 const struct input_event *event) 186 { 187 client->buffer[client->head++] = *event; 188 client->head &= client->bufsize - 1; 189 190 if (unlikely(client->head == client->tail)) { 191 /* 192 * This effectively "drops" all unconsumed events, leaving 193 * EV_SYN/SYN_DROPPED plus the newest event in the queue. 194 */ 195 client->tail = (client->head - 2) & (client->bufsize - 1); 196 197 client->buffer[client->tail].time = event->time; 198 client->buffer[client->tail].type = EV_SYN; 199 client->buffer[client->tail].code = SYN_DROPPED; 200 client->buffer[client->tail].value = 0; 201 202 client->packet_head = client->tail; 203 } 204 205 if (event->type == EV_SYN && event->code == SYN_REPORT) { 206 client->packet_head = client->head; 207 kill_fasync(&client->fasync, SIGIO, POLL_IN); 208 } 209 } 210 211 static void evdev_pass_values(struct evdev_client *client, 212 const struct input_value *vals, unsigned int count, 213 ktime_t *ev_time) 214 { 215 struct evdev *evdev = client->evdev; 216 const struct input_value *v; 217 struct input_event event; 218 bool wakeup = false; 219 220 if (client->revoked) 221 return; 222 223 event.time = ktime_to_timeval(ev_time[client->clk_type]); 224 225 /* Interrupts are disabled, just acquire the lock. */ 226 spin_lock(&client->buffer_lock); 227 228 for (v = vals; v != vals + count; v++) { 229 event.type = v->type; 230 event.code = v->code; 231 event.value = v->value; 232 __pass_event(client, &event); 233 if (v->type == EV_SYN && v->code == SYN_REPORT) 234 wakeup = true; 235 } 236 237 spin_unlock(&client->buffer_lock); 238 239 if (wakeup) 240 wake_up_interruptible(&evdev->wait); 241 } 242 243 /* 244 * Pass incoming events to all connected clients. 245 */ 246 static void evdev_events(struct input_handle *handle, 247 const struct input_value *vals, unsigned int count) 248 { 249 struct evdev *evdev = handle->private; 250 struct evdev_client *client; 251 ktime_t ev_time[EV_CLK_MAX]; 252 253 ev_time[EV_CLK_MONO] = ktime_get(); 254 ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]); 255 ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO], 256 TK_OFFS_BOOT); 257 258 rcu_read_lock(); 259 260 client = rcu_dereference(evdev->grab); 261 262 if (client) 263 evdev_pass_values(client, vals, count, ev_time); 264 else 265 list_for_each_entry_rcu(client, &evdev->client_list, node) 266 evdev_pass_values(client, vals, count, ev_time); 267 268 rcu_read_unlock(); 269 } 270 271 /* 272 * Pass incoming event to all connected clients. 273 */ 274 static void evdev_event(struct input_handle *handle, 275 unsigned int type, unsigned int code, int value) 276 { 277 struct input_value vals[] = { { type, code, value } }; 278 279 evdev_events(handle, vals, 1); 280 } 281 282 static int evdev_fasync(int fd, struct file *file, int on) 283 { 284 struct evdev_client *client = file->private_data; 285 286 return fasync_helper(fd, file, on, &client->fasync); 287 } 288 289 static int evdev_flush(struct file *file, fl_owner_t id) 290 { 291 struct evdev_client *client = file->private_data; 292 struct evdev *evdev = client->evdev; 293 int retval; 294 295 retval = mutex_lock_interruptible(&evdev->mutex); 296 if (retval) 297 return retval; 298 299 if (!evdev->exist || client->revoked) 300 retval = -ENODEV; 301 else 302 retval = input_flush_device(&evdev->handle, file); 303 304 mutex_unlock(&evdev->mutex); 305 return retval; 306 } 307 308 static void evdev_free(struct device *dev) 309 { 310 struct evdev *evdev = container_of(dev, struct evdev, dev); 311 312 input_put_device(evdev->handle.dev); 313 kfree(evdev); 314 } 315 316 /* 317 * Grabs an event device (along with underlying input device). 318 * This function is called with evdev->mutex taken. 319 */ 320 static int evdev_grab(struct evdev *evdev, struct evdev_client *client) 321 { 322 int error; 323 324 if (evdev->grab) 325 return -EBUSY; 326 327 error = input_grab_device(&evdev->handle); 328 if (error) 329 return error; 330 331 rcu_assign_pointer(evdev->grab, client); 332 333 return 0; 334 } 335 336 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client) 337 { 338 struct evdev_client *grab = rcu_dereference_protected(evdev->grab, 339 lockdep_is_held(&evdev->mutex)); 340 341 if (grab != client) 342 return -EINVAL; 343 344 rcu_assign_pointer(evdev->grab, NULL); 345 synchronize_rcu(); 346 input_release_device(&evdev->handle); 347 348 return 0; 349 } 350 351 static void evdev_attach_client(struct evdev *evdev, 352 struct evdev_client *client) 353 { 354 spin_lock(&evdev->client_lock); 355 list_add_tail_rcu(&client->node, &evdev->client_list); 356 spin_unlock(&evdev->client_lock); 357 } 358 359 static void evdev_detach_client(struct evdev *evdev, 360 struct evdev_client *client) 361 { 362 spin_lock(&evdev->client_lock); 363 list_del_rcu(&client->node); 364 spin_unlock(&evdev->client_lock); 365 synchronize_rcu(); 366 } 367 368 static int evdev_open_device(struct evdev *evdev) 369 { 370 int retval; 371 372 retval = mutex_lock_interruptible(&evdev->mutex); 373 if (retval) 374 return retval; 375 376 if (!evdev->exist) 377 retval = -ENODEV; 378 else if (!evdev->open++) { 379 retval = input_open_device(&evdev->handle); 380 if (retval) 381 evdev->open--; 382 } 383 384 mutex_unlock(&evdev->mutex); 385 return retval; 386 } 387 388 static void evdev_close_device(struct evdev *evdev) 389 { 390 mutex_lock(&evdev->mutex); 391 392 if (evdev->exist && !--evdev->open) 393 input_close_device(&evdev->handle); 394 395 mutex_unlock(&evdev->mutex); 396 } 397 398 /* 399 * Wake up users waiting for IO so they can disconnect from 400 * dead device. 401 */ 402 static void evdev_hangup(struct evdev *evdev) 403 { 404 struct evdev_client *client; 405 406 spin_lock(&evdev->client_lock); 407 list_for_each_entry(client, &evdev->client_list, node) 408 kill_fasync(&client->fasync, SIGIO, POLL_HUP); 409 spin_unlock(&evdev->client_lock); 410 411 wake_up_interruptible(&evdev->wait); 412 } 413 414 static int evdev_release(struct inode *inode, struct file *file) 415 { 416 struct evdev_client *client = file->private_data; 417 struct evdev *evdev = client->evdev; 418 419 mutex_lock(&evdev->mutex); 420 evdev_ungrab(evdev, client); 421 mutex_unlock(&evdev->mutex); 422 423 evdev_detach_client(evdev, client); 424 425 kvfree(client); 426 427 evdev_close_device(evdev); 428 429 return 0; 430 } 431 432 static unsigned int evdev_compute_buffer_size(struct input_dev *dev) 433 { 434 unsigned int n_events = 435 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS, 436 EVDEV_MIN_BUFFER_SIZE); 437 438 return roundup_pow_of_two(n_events); 439 } 440 441 static int evdev_open(struct inode *inode, struct file *file) 442 { 443 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev); 444 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev); 445 unsigned int size = sizeof(struct evdev_client) + 446 bufsize * sizeof(struct input_event); 447 struct evdev_client *client; 448 int error; 449 450 client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); 451 if (!client) 452 client = vzalloc(size); 453 if (!client) 454 return -ENOMEM; 455 456 client->bufsize = bufsize; 457 spin_lock_init(&client->buffer_lock); 458 client->evdev = evdev; 459 evdev_attach_client(evdev, client); 460 461 error = evdev_open_device(evdev); 462 if (error) 463 goto err_free_client; 464 465 file->private_data = client; 466 nonseekable_open(inode, file); 467 468 return 0; 469 470 err_free_client: 471 evdev_detach_client(evdev, client); 472 kvfree(client); 473 return error; 474 } 475 476 static ssize_t evdev_write(struct file *file, const char __user *buffer, 477 size_t count, loff_t *ppos) 478 { 479 struct evdev_client *client = file->private_data; 480 struct evdev *evdev = client->evdev; 481 struct input_event event; 482 int retval = 0; 483 484 if (count != 0 && count < input_event_size()) 485 return -EINVAL; 486 487 retval = mutex_lock_interruptible(&evdev->mutex); 488 if (retval) 489 return retval; 490 491 if (!evdev->exist || client->revoked) { 492 retval = -ENODEV; 493 goto out; 494 } 495 496 while (retval + input_event_size() <= count) { 497 498 if (input_event_from_user(buffer + retval, &event)) { 499 retval = -EFAULT; 500 goto out; 501 } 502 retval += input_event_size(); 503 504 input_inject_event(&evdev->handle, 505 event.type, event.code, event.value); 506 } 507 508 out: 509 mutex_unlock(&evdev->mutex); 510 return retval; 511 } 512 513 static int evdev_fetch_next_event(struct evdev_client *client, 514 struct input_event *event) 515 { 516 int have_event; 517 518 spin_lock_irq(&client->buffer_lock); 519 520 have_event = client->packet_head != client->tail; 521 if (have_event) { 522 *event = client->buffer[client->tail++]; 523 client->tail &= client->bufsize - 1; 524 } 525 526 spin_unlock_irq(&client->buffer_lock); 527 528 return have_event; 529 } 530 531 static ssize_t evdev_read(struct file *file, char __user *buffer, 532 size_t count, loff_t *ppos) 533 { 534 struct evdev_client *client = file->private_data; 535 struct evdev *evdev = client->evdev; 536 struct input_event event; 537 size_t read = 0; 538 int error; 539 540 if (count != 0 && count < input_event_size()) 541 return -EINVAL; 542 543 for (;;) { 544 if (!evdev->exist || client->revoked) 545 return -ENODEV; 546 547 if (client->packet_head == client->tail && 548 (file->f_flags & O_NONBLOCK)) 549 return -EAGAIN; 550 551 /* 552 * count == 0 is special - no IO is done but we check 553 * for error conditions (see above). 554 */ 555 if (count == 0) 556 break; 557 558 while (read + input_event_size() <= count && 559 evdev_fetch_next_event(client, &event)) { 560 561 if (input_event_to_user(buffer + read, &event)) 562 return -EFAULT; 563 564 read += input_event_size(); 565 } 566 567 if (read) 568 break; 569 570 if (!(file->f_flags & O_NONBLOCK)) { 571 error = wait_event_interruptible(evdev->wait, 572 client->packet_head != client->tail || 573 !evdev->exist || client->revoked); 574 if (error) 575 return error; 576 } 577 } 578 579 return read; 580 } 581 582 /* No kernel lock - fine */ 583 static unsigned int evdev_poll(struct file *file, poll_table *wait) 584 { 585 struct evdev_client *client = file->private_data; 586 struct evdev *evdev = client->evdev; 587 unsigned int mask; 588 589 poll_wait(file, &evdev->wait, wait); 590 591 if (evdev->exist && !client->revoked) 592 mask = POLLOUT | POLLWRNORM; 593 else 594 mask = POLLHUP | POLLERR; 595 596 if (client->packet_head != client->tail) 597 mask |= POLLIN | POLLRDNORM; 598 599 return mask; 600 } 601 602 #ifdef CONFIG_COMPAT 603 604 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8) 605 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1) 606 607 #ifdef __BIG_ENDIAN 608 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 609 unsigned int maxlen, void __user *p, int compat) 610 { 611 int len, i; 612 613 if (compat) { 614 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t); 615 if (len > maxlen) 616 len = maxlen; 617 618 for (i = 0; i < len / sizeof(compat_long_t); i++) 619 if (copy_to_user((compat_long_t __user *) p + i, 620 (compat_long_t *) bits + 621 i + 1 - ((i % 2) << 1), 622 sizeof(compat_long_t))) 623 return -EFAULT; 624 } else { 625 len = BITS_TO_LONGS(maxbit) * sizeof(long); 626 if (len > maxlen) 627 len = maxlen; 628 629 if (copy_to_user(p, bits, len)) 630 return -EFAULT; 631 } 632 633 return len; 634 } 635 #else 636 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 637 unsigned int maxlen, void __user *p, int compat) 638 { 639 int len = compat ? 640 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) : 641 BITS_TO_LONGS(maxbit) * sizeof(long); 642 643 if (len > maxlen) 644 len = maxlen; 645 646 return copy_to_user(p, bits, len) ? -EFAULT : len; 647 } 648 #endif /* __BIG_ENDIAN */ 649 650 #else 651 652 static int bits_to_user(unsigned long *bits, unsigned int maxbit, 653 unsigned int maxlen, void __user *p, int compat) 654 { 655 int len = BITS_TO_LONGS(maxbit) * sizeof(long); 656 657 if (len > maxlen) 658 len = maxlen; 659 660 return copy_to_user(p, bits, len) ? -EFAULT : len; 661 } 662 663 #endif /* CONFIG_COMPAT */ 664 665 static int str_to_user(const char *str, unsigned int maxlen, void __user *p) 666 { 667 int len; 668 669 if (!str) 670 return -ENOENT; 671 672 len = strlen(str) + 1; 673 if (len > maxlen) 674 len = maxlen; 675 676 return copy_to_user(p, str, len) ? -EFAULT : len; 677 } 678 679 static int handle_eviocgbit(struct input_dev *dev, 680 unsigned int type, unsigned int size, 681 void __user *p, int compat_mode) 682 { 683 unsigned long *bits; 684 int len; 685 686 switch (type) { 687 688 case 0: bits = dev->evbit; len = EV_MAX; break; 689 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; 690 case EV_REL: bits = dev->relbit; len = REL_MAX; break; 691 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; 692 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; 693 case EV_LED: bits = dev->ledbit; len = LED_MAX; break; 694 case EV_SND: bits = dev->sndbit; len = SND_MAX; break; 695 case EV_FF: bits = dev->ffbit; len = FF_MAX; break; 696 case EV_SW: bits = dev->swbit; len = SW_MAX; break; 697 default: return -EINVAL; 698 } 699 700 return bits_to_user(bits, len, size, p, compat_mode); 701 } 702 703 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p) 704 { 705 struct input_keymap_entry ke = { 706 .len = sizeof(unsigned int), 707 .flags = 0, 708 }; 709 int __user *ip = (int __user *)p; 710 int error; 711 712 /* legacy case */ 713 if (copy_from_user(ke.scancode, p, sizeof(unsigned int))) 714 return -EFAULT; 715 716 error = input_get_keycode(dev, &ke); 717 if (error) 718 return error; 719 720 if (put_user(ke.keycode, ip + 1)) 721 return -EFAULT; 722 723 return 0; 724 } 725 726 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p) 727 { 728 struct input_keymap_entry ke; 729 int error; 730 731 if (copy_from_user(&ke, p, sizeof(ke))) 732 return -EFAULT; 733 734 error = input_get_keycode(dev, &ke); 735 if (error) 736 return error; 737 738 if (copy_to_user(p, &ke, sizeof(ke))) 739 return -EFAULT; 740 741 return 0; 742 } 743 744 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p) 745 { 746 struct input_keymap_entry ke = { 747 .len = sizeof(unsigned int), 748 .flags = 0, 749 }; 750 int __user *ip = (int __user *)p; 751 752 if (copy_from_user(ke.scancode, p, sizeof(unsigned int))) 753 return -EFAULT; 754 755 if (get_user(ke.keycode, ip + 1)) 756 return -EFAULT; 757 758 return input_set_keycode(dev, &ke); 759 } 760 761 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p) 762 { 763 struct input_keymap_entry ke; 764 765 if (copy_from_user(&ke, p, sizeof(ke))) 766 return -EFAULT; 767 768 if (ke.len > sizeof(ke.scancode)) 769 return -EINVAL; 770 771 return input_set_keycode(dev, &ke); 772 } 773 774 /* 775 * If we transfer state to the user, we should flush all pending events 776 * of the same type from the client's queue. Otherwise, they might end up 777 * with duplicate events, which can screw up client's state tracking. 778 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED 779 * event so user-space will notice missing events. 780 * 781 * LOCKING: 782 * We need to take event_lock before buffer_lock to avoid dead-locks. But we 783 * need the even_lock only to guarantee consistent state. We can safely release 784 * it while flushing the queue. This allows input-core to handle filters while 785 * we flush the queue. 786 */ 787 static int evdev_handle_get_val(struct evdev_client *client, 788 struct input_dev *dev, unsigned int type, 789 unsigned long *bits, unsigned int maxbit, 790 unsigned int maxlen, void __user *p, 791 int compat) 792 { 793 int ret; 794 unsigned long *mem; 795 size_t len; 796 797 len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long); 798 mem = kmalloc(len, GFP_KERNEL); 799 if (!mem) 800 return -ENOMEM; 801 802 spin_lock_irq(&dev->event_lock); 803 spin_lock(&client->buffer_lock); 804 805 memcpy(mem, bits, len); 806 807 spin_unlock(&dev->event_lock); 808 809 __evdev_flush_queue(client, type); 810 811 spin_unlock_irq(&client->buffer_lock); 812 813 ret = bits_to_user(mem, maxbit, maxlen, p, compat); 814 if (ret < 0) 815 evdev_queue_syn_dropped(client); 816 817 kfree(mem); 818 819 return ret; 820 } 821 822 static int evdev_handle_mt_request(struct input_dev *dev, 823 unsigned int size, 824 int __user *ip) 825 { 826 const struct input_mt *mt = dev->mt; 827 unsigned int code; 828 int max_slots; 829 int i; 830 831 if (get_user(code, &ip[0])) 832 return -EFAULT; 833 if (!mt || !input_is_mt_value(code)) 834 return -EINVAL; 835 836 max_slots = (size - sizeof(__u32)) / sizeof(__s32); 837 for (i = 0; i < mt->num_slots && i < max_slots; i++) { 838 int value = input_mt_get_value(&mt->slots[i], code); 839 if (put_user(value, &ip[1 + i])) 840 return -EFAULT; 841 } 842 843 return 0; 844 } 845 846 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client, 847 struct file *file) 848 { 849 client->revoked = true; 850 evdev_ungrab(evdev, client); 851 input_flush_device(&evdev->handle, file); 852 wake_up_interruptible(&evdev->wait); 853 854 return 0; 855 } 856 857 static long evdev_do_ioctl(struct file *file, unsigned int cmd, 858 void __user *p, int compat_mode) 859 { 860 struct evdev_client *client = file->private_data; 861 struct evdev *evdev = client->evdev; 862 struct input_dev *dev = evdev->handle.dev; 863 struct input_absinfo abs; 864 struct ff_effect effect; 865 int __user *ip = (int __user *)p; 866 unsigned int i, t, u, v; 867 unsigned int size; 868 int error; 869 870 /* First we check for fixed-length commands */ 871 switch (cmd) { 872 873 case EVIOCGVERSION: 874 return put_user(EV_VERSION, ip); 875 876 case EVIOCGID: 877 if (copy_to_user(p, &dev->id, sizeof(struct input_id))) 878 return -EFAULT; 879 return 0; 880 881 case EVIOCGREP: 882 if (!test_bit(EV_REP, dev->evbit)) 883 return -ENOSYS; 884 if (put_user(dev->rep[REP_DELAY], ip)) 885 return -EFAULT; 886 if (put_user(dev->rep[REP_PERIOD], ip + 1)) 887 return -EFAULT; 888 return 0; 889 890 case EVIOCSREP: 891 if (!test_bit(EV_REP, dev->evbit)) 892 return -ENOSYS; 893 if (get_user(u, ip)) 894 return -EFAULT; 895 if (get_user(v, ip + 1)) 896 return -EFAULT; 897 898 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); 899 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); 900 901 return 0; 902 903 case EVIOCRMFF: 904 return input_ff_erase(dev, (int)(unsigned long) p, file); 905 906 case EVIOCGEFFECTS: 907 i = test_bit(EV_FF, dev->evbit) ? 908 dev->ff->max_effects : 0; 909 if (put_user(i, ip)) 910 return -EFAULT; 911 return 0; 912 913 case EVIOCGRAB: 914 if (p) 915 return evdev_grab(evdev, client); 916 else 917 return evdev_ungrab(evdev, client); 918 919 case EVIOCREVOKE: 920 if (p) 921 return -EINVAL; 922 else 923 return evdev_revoke(evdev, client, file); 924 925 case EVIOCSCLOCKID: 926 if (copy_from_user(&i, p, sizeof(unsigned int))) 927 return -EFAULT; 928 929 return evdev_set_clk_type(client, i); 930 931 case EVIOCGKEYCODE: 932 return evdev_handle_get_keycode(dev, p); 933 934 case EVIOCSKEYCODE: 935 return evdev_handle_set_keycode(dev, p); 936 937 case EVIOCGKEYCODE_V2: 938 return evdev_handle_get_keycode_v2(dev, p); 939 940 case EVIOCSKEYCODE_V2: 941 return evdev_handle_set_keycode_v2(dev, p); 942 } 943 944 size = _IOC_SIZE(cmd); 945 946 /* Now check variable-length commands */ 947 #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT)) 948 switch (EVIOC_MASK_SIZE(cmd)) { 949 950 case EVIOCGPROP(0): 951 return bits_to_user(dev->propbit, INPUT_PROP_MAX, 952 size, p, compat_mode); 953 954 case EVIOCGMTSLOTS(0): 955 return evdev_handle_mt_request(dev, size, ip); 956 957 case EVIOCGKEY(0): 958 return evdev_handle_get_val(client, dev, EV_KEY, dev->key, 959 KEY_MAX, size, p, compat_mode); 960 961 case EVIOCGLED(0): 962 return evdev_handle_get_val(client, dev, EV_LED, dev->led, 963 LED_MAX, size, p, compat_mode); 964 965 case EVIOCGSND(0): 966 return evdev_handle_get_val(client, dev, EV_SND, dev->snd, 967 SND_MAX, size, p, compat_mode); 968 969 case EVIOCGSW(0): 970 return evdev_handle_get_val(client, dev, EV_SW, dev->sw, 971 SW_MAX, size, p, compat_mode); 972 973 case EVIOCGNAME(0): 974 return str_to_user(dev->name, size, p); 975 976 case EVIOCGPHYS(0): 977 return str_to_user(dev->phys, size, p); 978 979 case EVIOCGUNIQ(0): 980 return str_to_user(dev->uniq, size, p); 981 982 case EVIOC_MASK_SIZE(EVIOCSFF): 983 if (input_ff_effect_from_user(p, size, &effect)) 984 return -EFAULT; 985 986 error = input_ff_upload(dev, &effect, file); 987 if (error) 988 return error; 989 990 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) 991 return -EFAULT; 992 993 return 0; 994 } 995 996 /* Multi-number variable-length handlers */ 997 if (_IOC_TYPE(cmd) != 'E') 998 return -EINVAL; 999 1000 if (_IOC_DIR(cmd) == _IOC_READ) { 1001 1002 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) 1003 return handle_eviocgbit(dev, 1004 _IOC_NR(cmd) & EV_MAX, size, 1005 p, compat_mode); 1006 1007 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { 1008 1009 if (!dev->absinfo) 1010 return -EINVAL; 1011 1012 t = _IOC_NR(cmd) & ABS_MAX; 1013 abs = dev->absinfo[t]; 1014 1015 if (copy_to_user(p, &abs, min_t(size_t, 1016 size, sizeof(struct input_absinfo)))) 1017 return -EFAULT; 1018 1019 return 0; 1020 } 1021 } 1022 1023 if (_IOC_DIR(cmd) == _IOC_WRITE) { 1024 1025 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { 1026 1027 if (!dev->absinfo) 1028 return -EINVAL; 1029 1030 t = _IOC_NR(cmd) & ABS_MAX; 1031 1032 if (copy_from_user(&abs, p, min_t(size_t, 1033 size, sizeof(struct input_absinfo)))) 1034 return -EFAULT; 1035 1036 if (size < sizeof(struct input_absinfo)) 1037 abs.resolution = 0; 1038 1039 /* We can't change number of reserved MT slots */ 1040 if (t == ABS_MT_SLOT) 1041 return -EINVAL; 1042 1043 /* 1044 * Take event lock to ensure that we are not 1045 * changing device parameters in the middle 1046 * of event. 1047 */ 1048 spin_lock_irq(&dev->event_lock); 1049 dev->absinfo[t] = abs; 1050 spin_unlock_irq(&dev->event_lock); 1051 1052 return 0; 1053 } 1054 } 1055 1056 return -EINVAL; 1057 } 1058 1059 static long evdev_ioctl_handler(struct file *file, unsigned int cmd, 1060 void __user *p, int compat_mode) 1061 { 1062 struct evdev_client *client = file->private_data; 1063 struct evdev *evdev = client->evdev; 1064 int retval; 1065 1066 retval = mutex_lock_interruptible(&evdev->mutex); 1067 if (retval) 1068 return retval; 1069 1070 if (!evdev->exist || client->revoked) { 1071 retval = -ENODEV; 1072 goto out; 1073 } 1074 1075 retval = evdev_do_ioctl(file, cmd, p, compat_mode); 1076 1077 out: 1078 mutex_unlock(&evdev->mutex); 1079 return retval; 1080 } 1081 1082 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 1083 { 1084 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0); 1085 } 1086 1087 #ifdef CONFIG_COMPAT 1088 static long evdev_ioctl_compat(struct file *file, 1089 unsigned int cmd, unsigned long arg) 1090 { 1091 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1); 1092 } 1093 #endif 1094 1095 static const struct file_operations evdev_fops = { 1096 .owner = THIS_MODULE, 1097 .read = evdev_read, 1098 .write = evdev_write, 1099 .poll = evdev_poll, 1100 .open = evdev_open, 1101 .release = evdev_release, 1102 .unlocked_ioctl = evdev_ioctl, 1103 #ifdef CONFIG_COMPAT 1104 .compat_ioctl = evdev_ioctl_compat, 1105 #endif 1106 .fasync = evdev_fasync, 1107 .flush = evdev_flush, 1108 .llseek = no_llseek, 1109 }; 1110 1111 /* 1112 * Mark device non-existent. This disables writes, ioctls and 1113 * prevents new users from opening the device. Already posted 1114 * blocking reads will stay, however new ones will fail. 1115 */ 1116 static void evdev_mark_dead(struct evdev *evdev) 1117 { 1118 mutex_lock(&evdev->mutex); 1119 evdev->exist = false; 1120 mutex_unlock(&evdev->mutex); 1121 } 1122 1123 static void evdev_cleanup(struct evdev *evdev) 1124 { 1125 struct input_handle *handle = &evdev->handle; 1126 1127 evdev_mark_dead(evdev); 1128 evdev_hangup(evdev); 1129 1130 cdev_del(&evdev->cdev); 1131 1132 /* evdev is marked dead so no one else accesses evdev->open */ 1133 if (evdev->open) { 1134 input_flush_device(handle, NULL); 1135 input_close_device(handle); 1136 } 1137 } 1138 1139 /* 1140 * Create new evdev device. Note that input core serializes calls 1141 * to connect and disconnect. 1142 */ 1143 static int evdev_connect(struct input_handler *handler, struct input_dev *dev, 1144 const struct input_device_id *id) 1145 { 1146 struct evdev *evdev; 1147 int minor; 1148 int dev_no; 1149 int error; 1150 1151 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true); 1152 if (minor < 0) { 1153 error = minor; 1154 pr_err("failed to reserve new minor: %d\n", error); 1155 return error; 1156 } 1157 1158 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL); 1159 if (!evdev) { 1160 error = -ENOMEM; 1161 goto err_free_minor; 1162 } 1163 1164 INIT_LIST_HEAD(&evdev->client_list); 1165 spin_lock_init(&evdev->client_lock); 1166 mutex_init(&evdev->mutex); 1167 init_waitqueue_head(&evdev->wait); 1168 evdev->exist = true; 1169 1170 dev_no = minor; 1171 /* Normalize device number if it falls into legacy range */ 1172 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS) 1173 dev_no -= EVDEV_MINOR_BASE; 1174 dev_set_name(&evdev->dev, "event%d", dev_no); 1175 1176 evdev->handle.dev = input_get_device(dev); 1177 evdev->handle.name = dev_name(&evdev->dev); 1178 evdev->handle.handler = handler; 1179 evdev->handle.private = evdev; 1180 1181 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor); 1182 evdev->dev.class = &input_class; 1183 evdev->dev.parent = &dev->dev; 1184 evdev->dev.release = evdev_free; 1185 device_initialize(&evdev->dev); 1186 1187 error = input_register_handle(&evdev->handle); 1188 if (error) 1189 goto err_free_evdev; 1190 1191 cdev_init(&evdev->cdev, &evdev_fops); 1192 evdev->cdev.kobj.parent = &evdev->dev.kobj; 1193 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1); 1194 if (error) 1195 goto err_unregister_handle; 1196 1197 error = device_add(&evdev->dev); 1198 if (error) 1199 goto err_cleanup_evdev; 1200 1201 return 0; 1202 1203 err_cleanup_evdev: 1204 evdev_cleanup(evdev); 1205 err_unregister_handle: 1206 input_unregister_handle(&evdev->handle); 1207 err_free_evdev: 1208 put_device(&evdev->dev); 1209 err_free_minor: 1210 input_free_minor(minor); 1211 return error; 1212 } 1213 1214 static void evdev_disconnect(struct input_handle *handle) 1215 { 1216 struct evdev *evdev = handle->private; 1217 1218 device_del(&evdev->dev); 1219 evdev_cleanup(evdev); 1220 input_free_minor(MINOR(evdev->dev.devt)); 1221 input_unregister_handle(handle); 1222 put_device(&evdev->dev); 1223 } 1224 1225 static const struct input_device_id evdev_ids[] = { 1226 { .driver_info = 1 }, /* Matches all devices */ 1227 { }, /* Terminating zero entry */ 1228 }; 1229 1230 MODULE_DEVICE_TABLE(input, evdev_ids); 1231 1232 static struct input_handler evdev_handler = { 1233 .event = evdev_event, 1234 .events = evdev_events, 1235 .connect = evdev_connect, 1236 .disconnect = evdev_disconnect, 1237 .legacy_minors = true, 1238 .minor = EVDEV_MINOR_BASE, 1239 .name = "evdev", 1240 .id_table = evdev_ids, 1241 }; 1242 1243 static int __init evdev_init(void) 1244 { 1245 return input_register_handler(&evdev_handler); 1246 } 1247 1248 static void __exit evdev_exit(void) 1249 { 1250 input_unregister_handler(&evdev_handler); 1251 } 1252 1253 module_init(evdev_init); 1254 module_exit(evdev_exit); 1255 1256 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 1257 MODULE_DESCRIPTION("Input driver event char devices"); 1258 MODULE_LICENSE("GPL"); 1259