Loading...
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
28struct 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
41struct 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
53static struct evdev *evdev_table[EVDEV_MINORS];
54static DEFINE_MUTEX(evdev_table_mutex);
55
56static 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 */
91static 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
118static 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
125static 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
144static 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 */
156static 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
172static 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
184static 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
192static 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
201static 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
221static 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 */
235static 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
247static 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
266static 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
275static 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
329static 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;
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
365static 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->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
383static 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;
390
391 if (count < input_event_size())
392 return -EINVAL;
393
394 if (client->packet_head == client->tail && evdev->exist &&
395 (file->f_flags & O_NONBLOCK))
396 return -EAGAIN;
397
398 retval = wait_event_interruptible(evdev->wait,
399 client->packet_head != client->tail || !evdev->exist);
400 if (retval)
401 return retval;
402
403 if (!evdev->exist)
404 return -ENODEV;
405
406 while (retval + input_event_size() <= count &&
407 evdev_fetch_next_event(client, &event)) {
408
409 if (input_event_to_user(buffer + retval, &event))
410 return -EFAULT;
411
412 retval += input_event_size();
413 }
414
415 return retval;
416}
417
418/* No kernel lock - fine */
419static unsigned int evdev_poll(struct file *file, poll_table *wait)
420{
421 struct evdev_client *client = file->private_data;
422 struct evdev *evdev = client->evdev;
423 unsigned int mask;
424
425 poll_wait(file, &evdev->wait, wait);
426
427 mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
428 if (client->packet_head != client->tail)
429 mask |= POLLIN | POLLRDNORM;
430
431 return mask;
432}
433
434#ifdef CONFIG_COMPAT
435
436#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
437#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
438
439#ifdef __BIG_ENDIAN
440static int bits_to_user(unsigned long *bits, unsigned int maxbit,
441 unsigned int maxlen, void __user *p, int compat)
442{
443 int len, i;
444
445 if (compat) {
446 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
447 if (len > maxlen)
448 len = maxlen;
449
450 for (i = 0; i < len / sizeof(compat_long_t); i++)
451 if (copy_to_user((compat_long_t __user *) p + i,
452 (compat_long_t *) bits +
453 i + 1 - ((i % 2) << 1),
454 sizeof(compat_long_t)))
455 return -EFAULT;
456 } else {
457 len = BITS_TO_LONGS(maxbit) * sizeof(long);
458 if (len > maxlen)
459 len = maxlen;
460
461 if (copy_to_user(p, bits, len))
462 return -EFAULT;
463 }
464
465 return len;
466}
467#else
468static int bits_to_user(unsigned long *bits, unsigned int maxbit,
469 unsigned int maxlen, void __user *p, int compat)
470{
471 int len = compat ?
472 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
473 BITS_TO_LONGS(maxbit) * sizeof(long);
474
475 if (len > maxlen)
476 len = maxlen;
477
478 return copy_to_user(p, bits, len) ? -EFAULT : len;
479}
480#endif /* __BIG_ENDIAN */
481
482#else
483
484static int bits_to_user(unsigned long *bits, unsigned int maxbit,
485 unsigned int maxlen, void __user *p, int compat)
486{
487 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
488
489 if (len > maxlen)
490 len = maxlen;
491
492 return copy_to_user(p, bits, len) ? -EFAULT : len;
493}
494
495#endif /* CONFIG_COMPAT */
496
497static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
498{
499 int len;
500
501 if (!str)
502 return -ENOENT;
503
504 len = strlen(str) + 1;
505 if (len > maxlen)
506 len = maxlen;
507
508 return copy_to_user(p, str, len) ? -EFAULT : len;
509}
510
511#define OLD_KEY_MAX 0x1ff
512static int handle_eviocgbit(struct input_dev *dev,
513 unsigned int type, unsigned int size,
514 void __user *p, int compat_mode)
515{
516 static unsigned long keymax_warn_time;
517 unsigned long *bits;
518 int len;
519
520 switch (type) {
521
522 case 0: bits = dev->evbit; len = EV_MAX; break;
523 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
524 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
525 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
526 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
527 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
528 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
529 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
530 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
531 default: return -EINVAL;
532 }
533
534 /*
535 * Work around bugs in userspace programs that like to do
536 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
537 * should be in bytes, not in bits.
538 */
539 if (type == EV_KEY && size == OLD_KEY_MAX) {
540 len = OLD_KEY_MAX;
541 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
542 pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
543 "limiting output to %zu bytes. See "
544 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
545 OLD_KEY_MAX,
546 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
547 }
548
549 return bits_to_user(bits, len, size, p, compat_mode);
550}
551#undef OLD_KEY_MAX
552
553static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
554{
555 struct input_keymap_entry ke = {
556 .len = sizeof(unsigned int),
557 .flags = 0,
558 };
559 int __user *ip = (int __user *)p;
560 int error;
561
562 /* legacy case */
563 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
564 return -EFAULT;
565
566 error = input_get_keycode(dev, &ke);
567 if (error)
568 return error;
569
570 if (put_user(ke.keycode, ip + 1))
571 return -EFAULT;
572
573 return 0;
574}
575
576static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
577{
578 struct input_keymap_entry ke;
579 int error;
580
581 if (copy_from_user(&ke, p, sizeof(ke)))
582 return -EFAULT;
583
584 error = input_get_keycode(dev, &ke);
585 if (error)
586 return error;
587
588 if (copy_to_user(p, &ke, sizeof(ke)))
589 return -EFAULT;
590
591 return 0;
592}
593
594static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
595{
596 struct input_keymap_entry ke = {
597 .len = sizeof(unsigned int),
598 .flags = 0,
599 };
600 int __user *ip = (int __user *)p;
601
602 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
603 return -EFAULT;
604
605 if (get_user(ke.keycode, ip + 1))
606 return -EFAULT;
607
608 return input_set_keycode(dev, &ke);
609}
610
611static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
612{
613 struct input_keymap_entry ke;
614
615 if (copy_from_user(&ke, p, sizeof(ke)))
616 return -EFAULT;
617
618 if (ke.len > sizeof(ke.scancode))
619 return -EINVAL;
620
621 return input_set_keycode(dev, &ke);
622}
623
624static long evdev_do_ioctl(struct file *file, unsigned int cmd,
625 void __user *p, int compat_mode)
626{
627 struct evdev_client *client = file->private_data;
628 struct evdev *evdev = client->evdev;
629 struct input_dev *dev = evdev->handle.dev;
630 struct input_absinfo abs;
631 struct ff_effect effect;
632 int __user *ip = (int __user *)p;
633 unsigned int i, t, u, v;
634 unsigned int size;
635 int error;
636
637 /* First we check for fixed-length commands */
638 switch (cmd) {
639
640 case EVIOCGVERSION:
641 return put_user(EV_VERSION, ip);
642
643 case EVIOCGID:
644 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
645 return -EFAULT;
646 return 0;
647
648 case EVIOCGREP:
649 if (!test_bit(EV_REP, dev->evbit))
650 return -ENOSYS;
651 if (put_user(dev->rep[REP_DELAY], ip))
652 return -EFAULT;
653 if (put_user(dev->rep[REP_PERIOD], ip + 1))
654 return -EFAULT;
655 return 0;
656
657 case EVIOCSREP:
658 if (!test_bit(EV_REP, dev->evbit))
659 return -ENOSYS;
660 if (get_user(u, ip))
661 return -EFAULT;
662 if (get_user(v, ip + 1))
663 return -EFAULT;
664
665 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
666 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
667
668 return 0;
669
670 case EVIOCRMFF:
671 return input_ff_erase(dev, (int)(unsigned long) p, file);
672
673 case EVIOCGEFFECTS:
674 i = test_bit(EV_FF, dev->evbit) ?
675 dev->ff->max_effects : 0;
676 if (put_user(i, ip))
677 return -EFAULT;
678 return 0;
679
680 case EVIOCGRAB:
681 if (p)
682 return evdev_grab(evdev, client);
683 else
684 return evdev_ungrab(evdev, client);
685
686 case EVIOCGKEYCODE:
687 return evdev_handle_get_keycode(dev, p);
688
689 case EVIOCSKEYCODE:
690 return evdev_handle_set_keycode(dev, p);
691
692 case EVIOCGKEYCODE_V2:
693 return evdev_handle_get_keycode_v2(dev, p);
694
695 case EVIOCSKEYCODE_V2:
696 return evdev_handle_set_keycode_v2(dev, p);
697 }
698
699 size = _IOC_SIZE(cmd);
700
701 /* Now check variable-length commands */
702#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
703 switch (EVIOC_MASK_SIZE(cmd)) {
704
705 case EVIOCGPROP(0):
706 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
707 size, p, compat_mode);
708
709 case EVIOCGKEY(0):
710 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
711
712 case EVIOCGLED(0):
713 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
714
715 case EVIOCGSND(0):
716 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
717
718 case EVIOCGSW(0):
719 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
720
721 case EVIOCGNAME(0):
722 return str_to_user(dev->name, size, p);
723
724 case EVIOCGPHYS(0):
725 return str_to_user(dev->phys, size, p);
726
727 case EVIOCGUNIQ(0):
728 return str_to_user(dev->uniq, size, p);
729
730 case EVIOC_MASK_SIZE(EVIOCSFF):
731 if (input_ff_effect_from_user(p, size, &effect))
732 return -EFAULT;
733
734 error = input_ff_upload(dev, &effect, file);
735
736 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
737 return -EFAULT;
738
739 return error;
740 }
741
742 /* Multi-number variable-length handlers */
743 if (_IOC_TYPE(cmd) != 'E')
744 return -EINVAL;
745
746 if (_IOC_DIR(cmd) == _IOC_READ) {
747
748 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
749 return handle_eviocgbit(dev,
750 _IOC_NR(cmd) & EV_MAX, size,
751 p, compat_mode);
752
753 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
754
755 if (!dev->absinfo)
756 return -EINVAL;
757
758 t = _IOC_NR(cmd) & ABS_MAX;
759 abs = dev->absinfo[t];
760
761 if (copy_to_user(p, &abs, min_t(size_t,
762 size, sizeof(struct input_absinfo))))
763 return -EFAULT;
764
765 return 0;
766 }
767 }
768
769 if (_IOC_DIR(cmd) == _IOC_WRITE) {
770
771 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
772
773 if (!dev->absinfo)
774 return -EINVAL;
775
776 t = _IOC_NR(cmd) & ABS_MAX;
777
778 if (copy_from_user(&abs, p, min_t(size_t,
779 size, sizeof(struct input_absinfo))))
780 return -EFAULT;
781
782 if (size < sizeof(struct input_absinfo))
783 abs.resolution = 0;
784
785 /* We can't change number of reserved MT slots */
786 if (t == ABS_MT_SLOT)
787 return -EINVAL;
788
789 /*
790 * Take event lock to ensure that we are not
791 * changing device parameters in the middle
792 * of event.
793 */
794 spin_lock_irq(&dev->event_lock);
795 dev->absinfo[t] = abs;
796 spin_unlock_irq(&dev->event_lock);
797
798 return 0;
799 }
800 }
801
802 return -EINVAL;
803}
804
805static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
806 void __user *p, int compat_mode)
807{
808 struct evdev_client *client = file->private_data;
809 struct evdev *evdev = client->evdev;
810 int retval;
811
812 retval = mutex_lock_interruptible(&evdev->mutex);
813 if (retval)
814 return retval;
815
816 if (!evdev->exist) {
817 retval = -ENODEV;
818 goto out;
819 }
820
821 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
822
823 out:
824 mutex_unlock(&evdev->mutex);
825 return retval;
826}
827
828static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
829{
830 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
831}
832
833#ifdef CONFIG_COMPAT
834static long evdev_ioctl_compat(struct file *file,
835 unsigned int cmd, unsigned long arg)
836{
837 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
838}
839#endif
840
841static const struct file_operations evdev_fops = {
842 .owner = THIS_MODULE,
843 .read = evdev_read,
844 .write = evdev_write,
845 .poll = evdev_poll,
846 .open = evdev_open,
847 .release = evdev_release,
848 .unlocked_ioctl = evdev_ioctl,
849#ifdef CONFIG_COMPAT
850 .compat_ioctl = evdev_ioctl_compat,
851#endif
852 .fasync = evdev_fasync,
853 .flush = evdev_flush,
854 .llseek = no_llseek,
855};
856
857static int evdev_install_chrdev(struct evdev *evdev)
858{
859 /*
860 * No need to do any locking here as calls to connect and
861 * disconnect are serialized by the input core
862 */
863 evdev_table[evdev->minor] = evdev;
864 return 0;
865}
866
867static void evdev_remove_chrdev(struct evdev *evdev)
868{
869 /*
870 * Lock evdev table to prevent race with evdev_open()
871 */
872 mutex_lock(&evdev_table_mutex);
873 evdev_table[evdev->minor] = NULL;
874 mutex_unlock(&evdev_table_mutex);
875}
876
877/*
878 * Mark device non-existent. This disables writes, ioctls and
879 * prevents new users from opening the device. Already posted
880 * blocking reads will stay, however new ones will fail.
881 */
882static void evdev_mark_dead(struct evdev *evdev)
883{
884 mutex_lock(&evdev->mutex);
885 evdev->exist = false;
886 mutex_unlock(&evdev->mutex);
887}
888
889static void evdev_cleanup(struct evdev *evdev)
890{
891 struct input_handle *handle = &evdev->handle;
892
893 evdev_mark_dead(evdev);
894 evdev_hangup(evdev);
895 evdev_remove_chrdev(evdev);
896
897 /* evdev is marked dead so no one else accesses evdev->open */
898 if (evdev->open) {
899 input_flush_device(handle, NULL);
900 input_close_device(handle);
901 }
902}
903
904/*
905 * Create new evdev device. Note that input core serializes calls
906 * to connect and disconnect so we don't need to lock evdev_table here.
907 */
908static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
909 const struct input_device_id *id)
910{
911 struct evdev *evdev;
912 int minor;
913 int error;
914
915 for (minor = 0; minor < EVDEV_MINORS; minor++)
916 if (!evdev_table[minor])
917 break;
918
919 if (minor == EVDEV_MINORS) {
920 pr_err("no more free evdev devices\n");
921 return -ENFILE;
922 }
923
924 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
925 if (!evdev)
926 return -ENOMEM;
927
928 INIT_LIST_HEAD(&evdev->client_list);
929 spin_lock_init(&evdev->client_lock);
930 mutex_init(&evdev->mutex);
931 init_waitqueue_head(&evdev->wait);
932
933 dev_set_name(&evdev->dev, "event%d", minor);
934 evdev->exist = true;
935 evdev->minor = minor;
936
937 evdev->handle.dev = input_get_device(dev);
938 evdev->handle.name = dev_name(&evdev->dev);
939 evdev->handle.handler = handler;
940 evdev->handle.private = evdev;
941
942 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
943 evdev->dev.class = &input_class;
944 evdev->dev.parent = &dev->dev;
945 evdev->dev.release = evdev_free;
946 device_initialize(&evdev->dev);
947
948 error = input_register_handle(&evdev->handle);
949 if (error)
950 goto err_free_evdev;
951
952 error = evdev_install_chrdev(evdev);
953 if (error)
954 goto err_unregister_handle;
955
956 error = device_add(&evdev->dev);
957 if (error)
958 goto err_cleanup_evdev;
959
960 return 0;
961
962 err_cleanup_evdev:
963 evdev_cleanup(evdev);
964 err_unregister_handle:
965 input_unregister_handle(&evdev->handle);
966 err_free_evdev:
967 put_device(&evdev->dev);
968 return error;
969}
970
971static void evdev_disconnect(struct input_handle *handle)
972{
973 struct evdev *evdev = handle->private;
974
975 device_del(&evdev->dev);
976 evdev_cleanup(evdev);
977 input_unregister_handle(handle);
978 put_device(&evdev->dev);
979}
980
981static const struct input_device_id evdev_ids[] = {
982 { .driver_info = 1 }, /* Matches all devices */
983 { }, /* Terminating zero entry */
984};
985
986MODULE_DEVICE_TABLE(input, evdev_ids);
987
988static struct input_handler evdev_handler = {
989 .event = evdev_event,
990 .connect = evdev_connect,
991 .disconnect = evdev_disconnect,
992 .fops = &evdev_fops,
993 .minor = EVDEV_MINOR_BASE,
994 .name = "evdev",
995 .id_table = evdev_ids,
996};
997
998static int __init evdev_init(void)
999{
1000 return input_register_handler(&evdev_handler);
1001}
1002
1003static void __exit evdev_exit(void)
1004{
1005 input_unregister_handler(&evdev_handler);
1006}
1007
1008module_init(evdev_init);
1009module_exit(evdev_exit);
1010
1011MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1012MODULE_DESCRIPTION("Input driver event char devices");
1013MODULE_LICENSE("GPL");
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
31struct evdev {
32 int open;
33 struct input_handle handle;
34 wait_queue_head_t wait;
35 struct evdev_client __rcu *grab;
36 struct list_head client_list;
37 spinlock_t client_lock; /* protects client_list */
38 struct mutex mutex;
39 struct device dev;
40 struct cdev cdev;
41 bool exist;
42};
43
44struct evdev_client {
45 unsigned int head;
46 unsigned int tail;
47 unsigned int packet_head; /* [future] position of the first element of next packet */
48 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
49 struct fasync_struct *fasync;
50 struct evdev *evdev;
51 struct list_head node;
52 int clkid;
53 bool revoked;
54 unsigned int bufsize;
55 struct input_event buffer[];
56};
57
58/* flush queued events of type @type, caller must hold client->buffer_lock */
59static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
60{
61 unsigned int i, head, num;
62 unsigned int mask = client->bufsize - 1;
63 bool is_report;
64 struct input_event *ev;
65
66 BUG_ON(type == EV_SYN);
67
68 head = client->tail;
69 client->packet_head = client->tail;
70
71 /* init to 1 so a leading SYN_REPORT will not be dropped */
72 num = 1;
73
74 for (i = client->tail; i != client->head; i = (i + 1) & mask) {
75 ev = &client->buffer[i];
76 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
77
78 if (ev->type == type) {
79 /* drop matched entry */
80 continue;
81 } else if (is_report && !num) {
82 /* drop empty SYN_REPORT groups */
83 continue;
84 } else if (head != i) {
85 /* move entry to fill the gap */
86 client->buffer[head].time = ev->time;
87 client->buffer[head].type = ev->type;
88 client->buffer[head].code = ev->code;
89 client->buffer[head].value = ev->value;
90 }
91
92 num++;
93 head = (head + 1) & mask;
94
95 if (is_report) {
96 num = 0;
97 client->packet_head = head;
98 }
99 }
100
101 client->head = head;
102}
103
104/* queue SYN_DROPPED event */
105static void evdev_queue_syn_dropped(struct evdev_client *client)
106{
107 unsigned long flags;
108 struct input_event ev;
109 ktime_t time;
110
111 time = ktime_get();
112 if (client->clkid != CLOCK_MONOTONIC)
113 time = ktime_sub(time, ktime_get_monotonic_offset());
114
115 ev.time = ktime_to_timeval(time);
116 ev.type = EV_SYN;
117 ev.code = SYN_DROPPED;
118 ev.value = 0;
119
120 spin_lock_irqsave(&client->buffer_lock, flags);
121
122 client->buffer[client->head++] = ev;
123 client->head &= client->bufsize - 1;
124
125 if (unlikely(client->head == client->tail)) {
126 /* drop queue but keep our SYN_DROPPED event */
127 client->tail = (client->head - 1) & (client->bufsize - 1);
128 client->packet_head = client->tail;
129 }
130
131 spin_unlock_irqrestore(&client->buffer_lock, flags);
132}
133
134static void __pass_event(struct evdev_client *client,
135 const struct input_event *event)
136{
137 client->buffer[client->head++] = *event;
138 client->head &= client->bufsize - 1;
139
140 if (unlikely(client->head == client->tail)) {
141 /*
142 * This effectively "drops" all unconsumed events, leaving
143 * EV_SYN/SYN_DROPPED plus the newest event in the queue.
144 */
145 client->tail = (client->head - 2) & (client->bufsize - 1);
146
147 client->buffer[client->tail].time = event->time;
148 client->buffer[client->tail].type = EV_SYN;
149 client->buffer[client->tail].code = SYN_DROPPED;
150 client->buffer[client->tail].value = 0;
151
152 client->packet_head = client->tail;
153 }
154
155 if (event->type == EV_SYN && event->code == SYN_REPORT) {
156 client->packet_head = client->head;
157 kill_fasync(&client->fasync, SIGIO, POLL_IN);
158 }
159}
160
161static void evdev_pass_values(struct evdev_client *client,
162 const struct input_value *vals, unsigned int count,
163 ktime_t mono, ktime_t real)
164{
165 struct evdev *evdev = client->evdev;
166 const struct input_value *v;
167 struct input_event event;
168 bool wakeup = false;
169
170 if (client->revoked)
171 return;
172
173 event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
174 mono : real);
175
176 /* Interrupts are disabled, just acquire the lock. */
177 spin_lock(&client->buffer_lock);
178
179 for (v = vals; v != vals + count; v++) {
180 event.type = v->type;
181 event.code = v->code;
182 event.value = v->value;
183 __pass_event(client, &event);
184 if (v->type == EV_SYN && v->code == SYN_REPORT)
185 wakeup = true;
186 }
187
188 spin_unlock(&client->buffer_lock);
189
190 if (wakeup)
191 wake_up_interruptible(&evdev->wait);
192}
193
194/*
195 * Pass incoming events to all connected clients.
196 */
197static void evdev_events(struct input_handle *handle,
198 const struct input_value *vals, unsigned int count)
199{
200 struct evdev *evdev = handle->private;
201 struct evdev_client *client;
202 ktime_t time_mono, time_real;
203
204 time_mono = ktime_get();
205 time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
206
207 rcu_read_lock();
208
209 client = rcu_dereference(evdev->grab);
210
211 if (client)
212 evdev_pass_values(client, vals, count, time_mono, time_real);
213 else
214 list_for_each_entry_rcu(client, &evdev->client_list, node)
215 evdev_pass_values(client, vals, count,
216 time_mono, time_real);
217
218 rcu_read_unlock();
219}
220
221/*
222 * Pass incoming event to all connected clients.
223 */
224static void evdev_event(struct input_handle *handle,
225 unsigned int type, unsigned int code, int value)
226{
227 struct input_value vals[] = { { type, code, value } };
228
229 evdev_events(handle, vals, 1);
230}
231
232static int evdev_fasync(int fd, struct file *file, int on)
233{
234 struct evdev_client *client = file->private_data;
235
236 return fasync_helper(fd, file, on, &client->fasync);
237}
238
239static int evdev_flush(struct file *file, fl_owner_t id)
240{
241 struct evdev_client *client = file->private_data;
242 struct evdev *evdev = client->evdev;
243 int retval;
244
245 retval = mutex_lock_interruptible(&evdev->mutex);
246 if (retval)
247 return retval;
248
249 if (!evdev->exist || client->revoked)
250 retval = -ENODEV;
251 else
252 retval = input_flush_device(&evdev->handle, file);
253
254 mutex_unlock(&evdev->mutex);
255 return retval;
256}
257
258static void evdev_free(struct device *dev)
259{
260 struct evdev *evdev = container_of(dev, struct evdev, dev);
261
262 input_put_device(evdev->handle.dev);
263 kfree(evdev);
264}
265
266/*
267 * Grabs an event device (along with underlying input device).
268 * This function is called with evdev->mutex taken.
269 */
270static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
271{
272 int error;
273
274 if (evdev->grab)
275 return -EBUSY;
276
277 error = input_grab_device(&evdev->handle);
278 if (error)
279 return error;
280
281 rcu_assign_pointer(evdev->grab, client);
282
283 return 0;
284}
285
286static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
287{
288 struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
289 lockdep_is_held(&evdev->mutex));
290
291 if (grab != client)
292 return -EINVAL;
293
294 rcu_assign_pointer(evdev->grab, NULL);
295 synchronize_rcu();
296 input_release_device(&evdev->handle);
297
298 return 0;
299}
300
301static void evdev_attach_client(struct evdev *evdev,
302 struct evdev_client *client)
303{
304 spin_lock(&evdev->client_lock);
305 list_add_tail_rcu(&client->node, &evdev->client_list);
306 spin_unlock(&evdev->client_lock);
307}
308
309static void evdev_detach_client(struct evdev *evdev,
310 struct evdev_client *client)
311{
312 spin_lock(&evdev->client_lock);
313 list_del_rcu(&client->node);
314 spin_unlock(&evdev->client_lock);
315 synchronize_rcu();
316}
317
318static int evdev_open_device(struct evdev *evdev)
319{
320 int retval;
321
322 retval = mutex_lock_interruptible(&evdev->mutex);
323 if (retval)
324 return retval;
325
326 if (!evdev->exist)
327 retval = -ENODEV;
328 else if (!evdev->open++) {
329 retval = input_open_device(&evdev->handle);
330 if (retval)
331 evdev->open--;
332 }
333
334 mutex_unlock(&evdev->mutex);
335 return retval;
336}
337
338static void evdev_close_device(struct evdev *evdev)
339{
340 mutex_lock(&evdev->mutex);
341
342 if (evdev->exist && !--evdev->open)
343 input_close_device(&evdev->handle);
344
345 mutex_unlock(&evdev->mutex);
346}
347
348/*
349 * Wake up users waiting for IO so they can disconnect from
350 * dead device.
351 */
352static void evdev_hangup(struct evdev *evdev)
353{
354 struct evdev_client *client;
355
356 spin_lock(&evdev->client_lock);
357 list_for_each_entry(client, &evdev->client_list, node)
358 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
359 spin_unlock(&evdev->client_lock);
360
361 wake_up_interruptible(&evdev->wait);
362}
363
364static int evdev_release(struct inode *inode, struct file *file)
365{
366 struct evdev_client *client = file->private_data;
367 struct evdev *evdev = client->evdev;
368
369 mutex_lock(&evdev->mutex);
370 evdev_ungrab(evdev, client);
371 mutex_unlock(&evdev->mutex);
372
373 evdev_detach_client(evdev, client);
374
375 if (is_vmalloc_addr(client))
376 vfree(client);
377 else
378 kfree(client);
379
380 evdev_close_device(evdev);
381
382 return 0;
383}
384
385static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
386{
387 unsigned int n_events =
388 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
389 EVDEV_MIN_BUFFER_SIZE);
390
391 return roundup_pow_of_two(n_events);
392}
393
394static int evdev_open(struct inode *inode, struct file *file)
395{
396 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
397 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
398 unsigned int size = sizeof(struct evdev_client) +
399 bufsize * sizeof(struct input_event);
400 struct evdev_client *client;
401 int error;
402
403 client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
404 if (!client)
405 client = vzalloc(size);
406 if (!client)
407 return -ENOMEM;
408
409 client->bufsize = bufsize;
410 spin_lock_init(&client->buffer_lock);
411 client->evdev = evdev;
412 evdev_attach_client(evdev, client);
413
414 error = evdev_open_device(evdev);
415 if (error)
416 goto err_free_client;
417
418 file->private_data = client;
419 nonseekable_open(inode, file);
420
421 return 0;
422
423 err_free_client:
424 evdev_detach_client(evdev, client);
425 kfree(client);
426 return error;
427}
428
429static ssize_t evdev_write(struct file *file, const char __user *buffer,
430 size_t count, loff_t *ppos)
431{
432 struct evdev_client *client = file->private_data;
433 struct evdev *evdev = client->evdev;
434 struct input_event event;
435 int retval = 0;
436
437 if (count != 0 && count < input_event_size())
438 return -EINVAL;
439
440 retval = mutex_lock_interruptible(&evdev->mutex);
441 if (retval)
442 return retval;
443
444 if (!evdev->exist || client->revoked) {
445 retval = -ENODEV;
446 goto out;
447 }
448
449 while (retval + input_event_size() <= count) {
450
451 if (input_event_from_user(buffer + retval, &event)) {
452 retval = -EFAULT;
453 goto out;
454 }
455 retval += input_event_size();
456
457 input_inject_event(&evdev->handle,
458 event.type, event.code, event.value);
459 }
460
461 out:
462 mutex_unlock(&evdev->mutex);
463 return retval;
464}
465
466static int evdev_fetch_next_event(struct evdev_client *client,
467 struct input_event *event)
468{
469 int have_event;
470
471 spin_lock_irq(&client->buffer_lock);
472
473 have_event = client->packet_head != client->tail;
474 if (have_event) {
475 *event = client->buffer[client->tail++];
476 client->tail &= client->bufsize - 1;
477 }
478
479 spin_unlock_irq(&client->buffer_lock);
480
481 return have_event;
482}
483
484static ssize_t evdev_read(struct file *file, char __user *buffer,
485 size_t count, loff_t *ppos)
486{
487 struct evdev_client *client = file->private_data;
488 struct evdev *evdev = client->evdev;
489 struct input_event event;
490 size_t read = 0;
491 int error;
492
493 if (count != 0 && count < input_event_size())
494 return -EINVAL;
495
496 for (;;) {
497 if (!evdev->exist || client->revoked)
498 return -ENODEV;
499
500 if (client->packet_head == client->tail &&
501 (file->f_flags & O_NONBLOCK))
502 return -EAGAIN;
503
504 /*
505 * count == 0 is special - no IO is done but we check
506 * for error conditions (see above).
507 */
508 if (count == 0)
509 break;
510
511 while (read + input_event_size() <= count &&
512 evdev_fetch_next_event(client, &event)) {
513
514 if (input_event_to_user(buffer + read, &event))
515 return -EFAULT;
516
517 read += input_event_size();
518 }
519
520 if (read)
521 break;
522
523 if (!(file->f_flags & O_NONBLOCK)) {
524 error = wait_event_interruptible(evdev->wait,
525 client->packet_head != client->tail ||
526 !evdev->exist || client->revoked);
527 if (error)
528 return error;
529 }
530 }
531
532 return read;
533}
534
535/* No kernel lock - fine */
536static unsigned int evdev_poll(struct file *file, poll_table *wait)
537{
538 struct evdev_client *client = file->private_data;
539 struct evdev *evdev = client->evdev;
540 unsigned int mask;
541
542 poll_wait(file, &evdev->wait, wait);
543
544 if (evdev->exist && !client->revoked)
545 mask = POLLOUT | POLLWRNORM;
546 else
547 mask = POLLHUP | POLLERR;
548
549 if (client->packet_head != client->tail)
550 mask |= POLLIN | POLLRDNORM;
551
552 return mask;
553}
554
555#ifdef CONFIG_COMPAT
556
557#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
558#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
559
560#ifdef __BIG_ENDIAN
561static int bits_to_user(unsigned long *bits, unsigned int maxbit,
562 unsigned int maxlen, void __user *p, int compat)
563{
564 int len, i;
565
566 if (compat) {
567 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
568 if (len > maxlen)
569 len = maxlen;
570
571 for (i = 0; i < len / sizeof(compat_long_t); i++)
572 if (copy_to_user((compat_long_t __user *) p + i,
573 (compat_long_t *) bits +
574 i + 1 - ((i % 2) << 1),
575 sizeof(compat_long_t)))
576 return -EFAULT;
577 } else {
578 len = BITS_TO_LONGS(maxbit) * sizeof(long);
579 if (len > maxlen)
580 len = maxlen;
581
582 if (copy_to_user(p, bits, len))
583 return -EFAULT;
584 }
585
586 return len;
587}
588#else
589static int bits_to_user(unsigned long *bits, unsigned int maxbit,
590 unsigned int maxlen, void __user *p, int compat)
591{
592 int len = compat ?
593 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
594 BITS_TO_LONGS(maxbit) * sizeof(long);
595
596 if (len > maxlen)
597 len = maxlen;
598
599 return copy_to_user(p, bits, len) ? -EFAULT : len;
600}
601#endif /* __BIG_ENDIAN */
602
603#else
604
605static int bits_to_user(unsigned long *bits, unsigned int maxbit,
606 unsigned int maxlen, void __user *p, int compat)
607{
608 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
609
610 if (len > maxlen)
611 len = maxlen;
612
613 return copy_to_user(p, bits, len) ? -EFAULT : len;
614}
615
616#endif /* CONFIG_COMPAT */
617
618static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
619{
620 int len;
621
622 if (!str)
623 return -ENOENT;
624
625 len = strlen(str) + 1;
626 if (len > maxlen)
627 len = maxlen;
628
629 return copy_to_user(p, str, len) ? -EFAULT : len;
630}
631
632#define OLD_KEY_MAX 0x1ff
633static int handle_eviocgbit(struct input_dev *dev,
634 unsigned int type, unsigned int size,
635 void __user *p, int compat_mode)
636{
637 static unsigned long keymax_warn_time;
638 unsigned long *bits;
639 int len;
640
641 switch (type) {
642
643 case 0: bits = dev->evbit; len = EV_MAX; break;
644 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
645 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
646 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
647 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
648 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
649 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
650 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
651 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
652 default: return -EINVAL;
653 }
654
655 /*
656 * Work around bugs in userspace programs that like to do
657 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
658 * should be in bytes, not in bits.
659 */
660 if (type == EV_KEY && size == OLD_KEY_MAX) {
661 len = OLD_KEY_MAX;
662 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
663 pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
664 "limiting output to %zu bytes. See "
665 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
666 OLD_KEY_MAX,
667 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
668 }
669
670 return bits_to_user(bits, len, size, p, compat_mode);
671}
672#undef OLD_KEY_MAX
673
674static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
675{
676 struct input_keymap_entry ke = {
677 .len = sizeof(unsigned int),
678 .flags = 0,
679 };
680 int __user *ip = (int __user *)p;
681 int error;
682
683 /* legacy case */
684 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
685 return -EFAULT;
686
687 error = input_get_keycode(dev, &ke);
688 if (error)
689 return error;
690
691 if (put_user(ke.keycode, ip + 1))
692 return -EFAULT;
693
694 return 0;
695}
696
697static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
698{
699 struct input_keymap_entry ke;
700 int error;
701
702 if (copy_from_user(&ke, p, sizeof(ke)))
703 return -EFAULT;
704
705 error = input_get_keycode(dev, &ke);
706 if (error)
707 return error;
708
709 if (copy_to_user(p, &ke, sizeof(ke)))
710 return -EFAULT;
711
712 return 0;
713}
714
715static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
716{
717 struct input_keymap_entry ke = {
718 .len = sizeof(unsigned int),
719 .flags = 0,
720 };
721 int __user *ip = (int __user *)p;
722
723 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
724 return -EFAULT;
725
726 if (get_user(ke.keycode, ip + 1))
727 return -EFAULT;
728
729 return input_set_keycode(dev, &ke);
730}
731
732static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
733{
734 struct input_keymap_entry ke;
735
736 if (copy_from_user(&ke, p, sizeof(ke)))
737 return -EFAULT;
738
739 if (ke.len > sizeof(ke.scancode))
740 return -EINVAL;
741
742 return input_set_keycode(dev, &ke);
743}
744
745/*
746 * If we transfer state to the user, we should flush all pending events
747 * of the same type from the client's queue. Otherwise, they might end up
748 * with duplicate events, which can screw up client's state tracking.
749 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
750 * event so user-space will notice missing events.
751 *
752 * LOCKING:
753 * We need to take event_lock before buffer_lock to avoid dead-locks. But we
754 * need the even_lock only to guarantee consistent state. We can safely release
755 * it while flushing the queue. This allows input-core to handle filters while
756 * we flush the queue.
757 */
758static int evdev_handle_get_val(struct evdev_client *client,
759 struct input_dev *dev, unsigned int type,
760 unsigned long *bits, unsigned int max,
761 unsigned int size, void __user *p, int compat)
762{
763 int ret;
764 unsigned long *mem;
765
766 mem = kmalloc(sizeof(unsigned long) * max, GFP_KERNEL);
767 if (!mem)
768 return -ENOMEM;
769
770 spin_lock_irq(&dev->event_lock);
771 spin_lock(&client->buffer_lock);
772
773 memcpy(mem, bits, sizeof(unsigned long) * max);
774
775 spin_unlock(&dev->event_lock);
776
777 __evdev_flush_queue(client, type);
778
779 spin_unlock_irq(&client->buffer_lock);
780
781 ret = bits_to_user(mem, max, size, p, compat);
782 if (ret < 0)
783 evdev_queue_syn_dropped(client);
784
785 kfree(mem);
786
787 return ret;
788}
789
790static int evdev_handle_mt_request(struct input_dev *dev,
791 unsigned int size,
792 int __user *ip)
793{
794 const struct input_mt *mt = dev->mt;
795 unsigned int code;
796 int max_slots;
797 int i;
798
799 if (get_user(code, &ip[0]))
800 return -EFAULT;
801 if (!mt || !input_is_mt_value(code))
802 return -EINVAL;
803
804 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
805 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
806 int value = input_mt_get_value(&mt->slots[i], code);
807 if (put_user(value, &ip[1 + i]))
808 return -EFAULT;
809 }
810
811 return 0;
812}
813
814static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
815 struct file *file)
816{
817 client->revoked = true;
818 evdev_ungrab(evdev, client);
819 input_flush_device(&evdev->handle, file);
820 wake_up_interruptible(&evdev->wait);
821
822 return 0;
823}
824
825static long evdev_do_ioctl(struct file *file, unsigned int cmd,
826 void __user *p, int compat_mode)
827{
828 struct evdev_client *client = file->private_data;
829 struct evdev *evdev = client->evdev;
830 struct input_dev *dev = evdev->handle.dev;
831 struct input_absinfo abs;
832 struct ff_effect effect;
833 int __user *ip = (int __user *)p;
834 unsigned int i, t, u, v;
835 unsigned int size;
836 int error;
837
838 /* First we check for fixed-length commands */
839 switch (cmd) {
840
841 case EVIOCGVERSION:
842 return put_user(EV_VERSION, ip);
843
844 case EVIOCGID:
845 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
846 return -EFAULT;
847 return 0;
848
849 case EVIOCGREP:
850 if (!test_bit(EV_REP, dev->evbit))
851 return -ENOSYS;
852 if (put_user(dev->rep[REP_DELAY], ip))
853 return -EFAULT;
854 if (put_user(dev->rep[REP_PERIOD], ip + 1))
855 return -EFAULT;
856 return 0;
857
858 case EVIOCSREP:
859 if (!test_bit(EV_REP, dev->evbit))
860 return -ENOSYS;
861 if (get_user(u, ip))
862 return -EFAULT;
863 if (get_user(v, ip + 1))
864 return -EFAULT;
865
866 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
867 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
868
869 return 0;
870
871 case EVIOCRMFF:
872 return input_ff_erase(dev, (int)(unsigned long) p, file);
873
874 case EVIOCGEFFECTS:
875 i = test_bit(EV_FF, dev->evbit) ?
876 dev->ff->max_effects : 0;
877 if (put_user(i, ip))
878 return -EFAULT;
879 return 0;
880
881 case EVIOCGRAB:
882 if (p)
883 return evdev_grab(evdev, client);
884 else
885 return evdev_ungrab(evdev, client);
886
887 case EVIOCREVOKE:
888 if (p)
889 return -EINVAL;
890 else
891 return evdev_revoke(evdev, client, file);
892
893 case EVIOCSCLOCKID:
894 if (copy_from_user(&i, p, sizeof(unsigned int)))
895 return -EFAULT;
896 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
897 return -EINVAL;
898 client->clkid = i;
899 return 0;
900
901 case EVIOCGKEYCODE:
902 return evdev_handle_get_keycode(dev, p);
903
904 case EVIOCSKEYCODE:
905 return evdev_handle_set_keycode(dev, p);
906
907 case EVIOCGKEYCODE_V2:
908 return evdev_handle_get_keycode_v2(dev, p);
909
910 case EVIOCSKEYCODE_V2:
911 return evdev_handle_set_keycode_v2(dev, p);
912 }
913
914 size = _IOC_SIZE(cmd);
915
916 /* Now check variable-length commands */
917#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
918 switch (EVIOC_MASK_SIZE(cmd)) {
919
920 case EVIOCGPROP(0):
921 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
922 size, p, compat_mode);
923
924 case EVIOCGMTSLOTS(0):
925 return evdev_handle_mt_request(dev, size, ip);
926
927 case EVIOCGKEY(0):
928 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
929 KEY_MAX, size, p, compat_mode);
930
931 case EVIOCGLED(0):
932 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
933 LED_MAX, size, p, compat_mode);
934
935 case EVIOCGSND(0):
936 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
937 SND_MAX, size, p, compat_mode);
938
939 case EVIOCGSW(0):
940 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
941 SW_MAX, size, p, compat_mode);
942
943 case EVIOCGNAME(0):
944 return str_to_user(dev->name, size, p);
945
946 case EVIOCGPHYS(0):
947 return str_to_user(dev->phys, size, p);
948
949 case EVIOCGUNIQ(0):
950 return str_to_user(dev->uniq, size, p);
951
952 case EVIOC_MASK_SIZE(EVIOCSFF):
953 if (input_ff_effect_from_user(p, size, &effect))
954 return -EFAULT;
955
956 error = input_ff_upload(dev, &effect, file);
957 if (error)
958 return error;
959
960 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
961 return -EFAULT;
962
963 return 0;
964 }
965
966 /* Multi-number variable-length handlers */
967 if (_IOC_TYPE(cmd) != 'E')
968 return -EINVAL;
969
970 if (_IOC_DIR(cmd) == _IOC_READ) {
971
972 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
973 return handle_eviocgbit(dev,
974 _IOC_NR(cmd) & EV_MAX, size,
975 p, compat_mode);
976
977 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
978
979 if (!dev->absinfo)
980 return -EINVAL;
981
982 t = _IOC_NR(cmd) & ABS_MAX;
983 abs = dev->absinfo[t];
984
985 if (copy_to_user(p, &abs, min_t(size_t,
986 size, sizeof(struct input_absinfo))))
987 return -EFAULT;
988
989 return 0;
990 }
991 }
992
993 if (_IOC_DIR(cmd) == _IOC_WRITE) {
994
995 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
996
997 if (!dev->absinfo)
998 return -EINVAL;
999
1000 t = _IOC_NR(cmd) & ABS_MAX;
1001
1002 if (copy_from_user(&abs, p, min_t(size_t,
1003 size, sizeof(struct input_absinfo))))
1004 return -EFAULT;
1005
1006 if (size < sizeof(struct input_absinfo))
1007 abs.resolution = 0;
1008
1009 /* We can't change number of reserved MT slots */
1010 if (t == ABS_MT_SLOT)
1011 return -EINVAL;
1012
1013 /*
1014 * Take event lock to ensure that we are not
1015 * changing device parameters in the middle
1016 * of event.
1017 */
1018 spin_lock_irq(&dev->event_lock);
1019 dev->absinfo[t] = abs;
1020 spin_unlock_irq(&dev->event_lock);
1021
1022 return 0;
1023 }
1024 }
1025
1026 return -EINVAL;
1027}
1028
1029static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1030 void __user *p, int compat_mode)
1031{
1032 struct evdev_client *client = file->private_data;
1033 struct evdev *evdev = client->evdev;
1034 int retval;
1035
1036 retval = mutex_lock_interruptible(&evdev->mutex);
1037 if (retval)
1038 return retval;
1039
1040 if (!evdev->exist || client->revoked) {
1041 retval = -ENODEV;
1042 goto out;
1043 }
1044
1045 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1046
1047 out:
1048 mutex_unlock(&evdev->mutex);
1049 return retval;
1050}
1051
1052static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1053{
1054 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1055}
1056
1057#ifdef CONFIG_COMPAT
1058static long evdev_ioctl_compat(struct file *file,
1059 unsigned int cmd, unsigned long arg)
1060{
1061 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1062}
1063#endif
1064
1065static const struct file_operations evdev_fops = {
1066 .owner = THIS_MODULE,
1067 .read = evdev_read,
1068 .write = evdev_write,
1069 .poll = evdev_poll,
1070 .open = evdev_open,
1071 .release = evdev_release,
1072 .unlocked_ioctl = evdev_ioctl,
1073#ifdef CONFIG_COMPAT
1074 .compat_ioctl = evdev_ioctl_compat,
1075#endif
1076 .fasync = evdev_fasync,
1077 .flush = evdev_flush,
1078 .llseek = no_llseek,
1079};
1080
1081/*
1082 * Mark device non-existent. This disables writes, ioctls and
1083 * prevents new users from opening the device. Already posted
1084 * blocking reads will stay, however new ones will fail.
1085 */
1086static void evdev_mark_dead(struct evdev *evdev)
1087{
1088 mutex_lock(&evdev->mutex);
1089 evdev->exist = false;
1090 mutex_unlock(&evdev->mutex);
1091}
1092
1093static void evdev_cleanup(struct evdev *evdev)
1094{
1095 struct input_handle *handle = &evdev->handle;
1096
1097 evdev_mark_dead(evdev);
1098 evdev_hangup(evdev);
1099
1100 cdev_del(&evdev->cdev);
1101
1102 /* evdev is marked dead so no one else accesses evdev->open */
1103 if (evdev->open) {
1104 input_flush_device(handle, NULL);
1105 input_close_device(handle);
1106 }
1107}
1108
1109/*
1110 * Create new evdev device. Note that input core serializes calls
1111 * to connect and disconnect.
1112 */
1113static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1114 const struct input_device_id *id)
1115{
1116 struct evdev *evdev;
1117 int minor;
1118 int dev_no;
1119 int error;
1120
1121 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1122 if (minor < 0) {
1123 error = minor;
1124 pr_err("failed to reserve new minor: %d\n", error);
1125 return error;
1126 }
1127
1128 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1129 if (!evdev) {
1130 error = -ENOMEM;
1131 goto err_free_minor;
1132 }
1133
1134 INIT_LIST_HEAD(&evdev->client_list);
1135 spin_lock_init(&evdev->client_lock);
1136 mutex_init(&evdev->mutex);
1137 init_waitqueue_head(&evdev->wait);
1138 evdev->exist = true;
1139
1140 dev_no = minor;
1141 /* Normalize device number if it falls into legacy range */
1142 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1143 dev_no -= EVDEV_MINOR_BASE;
1144 dev_set_name(&evdev->dev, "event%d", dev_no);
1145
1146 evdev->handle.dev = input_get_device(dev);
1147 evdev->handle.name = dev_name(&evdev->dev);
1148 evdev->handle.handler = handler;
1149 evdev->handle.private = evdev;
1150
1151 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1152 evdev->dev.class = &input_class;
1153 evdev->dev.parent = &dev->dev;
1154 evdev->dev.release = evdev_free;
1155 device_initialize(&evdev->dev);
1156
1157 error = input_register_handle(&evdev->handle);
1158 if (error)
1159 goto err_free_evdev;
1160
1161 cdev_init(&evdev->cdev, &evdev_fops);
1162 evdev->cdev.kobj.parent = &evdev->dev.kobj;
1163 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1164 if (error)
1165 goto err_unregister_handle;
1166
1167 error = device_add(&evdev->dev);
1168 if (error)
1169 goto err_cleanup_evdev;
1170
1171 return 0;
1172
1173 err_cleanup_evdev:
1174 evdev_cleanup(evdev);
1175 err_unregister_handle:
1176 input_unregister_handle(&evdev->handle);
1177 err_free_evdev:
1178 put_device(&evdev->dev);
1179 err_free_minor:
1180 input_free_minor(minor);
1181 return error;
1182}
1183
1184static void evdev_disconnect(struct input_handle *handle)
1185{
1186 struct evdev *evdev = handle->private;
1187
1188 device_del(&evdev->dev);
1189 evdev_cleanup(evdev);
1190 input_free_minor(MINOR(evdev->dev.devt));
1191 input_unregister_handle(handle);
1192 put_device(&evdev->dev);
1193}
1194
1195static const struct input_device_id evdev_ids[] = {
1196 { .driver_info = 1 }, /* Matches all devices */
1197 { }, /* Terminating zero entry */
1198};
1199
1200MODULE_DEVICE_TABLE(input, evdev_ids);
1201
1202static struct input_handler evdev_handler = {
1203 .event = evdev_event,
1204 .events = evdev_events,
1205 .connect = evdev_connect,
1206 .disconnect = evdev_disconnect,
1207 .legacy_minors = true,
1208 .minor = EVDEV_MINOR_BASE,
1209 .name = "evdev",
1210 .id_table = evdev_ids,
1211};
1212
1213static int __init evdev_init(void)
1214{
1215 return input_register_handler(&evdev_handler);
1216}
1217
1218static void __exit evdev_exit(void)
1219{
1220 input_unregister_handler(&evdev_handler);
1221}
1222
1223module_init(evdev_init);
1224module_exit(evdev_exit);
1225
1226MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1227MODULE_DESCRIPTION("Input driver event char devices");
1228MODULE_LICENSE("GPL");