projects/linux·blob v2.6.39-rc2 · refs

1000 lines · 22.0 KiB

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