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