projects/linux·blob v3.3-rc5 · refs

1015 lines · 22.6 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 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->packet_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 = 0;
390
391 if (count < input_event_size())
392 return -EINVAL;
393
394 if (!(file->f_flags & O_NONBLOCK)) {
395 retval = wait_event_interruptible(evdev->wait,
396 client->packet_head != client->tail ||
397 !evdev->exist);
398 if (retval)
399 return retval;
400 }
401
402 if (!evdev->exist)
403 return -ENODEV;
404
405 while (retval + input_event_size() <= count &&
406 evdev_fetch_next_event(client, &event)) {
407
408 if (input_event_to_user(buffer + retval, &event))
409 return -EFAULT;
410
411 retval += input_event_size();
412 }
413
414 if (retval == 0 && (file->f_flags & O_NONBLOCK))
415 return -EAGAIN;
416
417 return retval;
418}
419
420/* No kernel lock - fine */
421static unsigned int evdev_poll(struct file *file, poll_table *wait)
422{
423 struct evdev_client *client = file->private_data;
424 struct evdev *evdev = client->evdev;
425 unsigned int mask;
426
427 poll_wait(file, &evdev->wait, wait);
428
429 mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
430 if (client->packet_head != client->tail)
431 mask |= POLLIN | POLLRDNORM;
432
433 return mask;
434}
435
436#ifdef CONFIG_COMPAT
437
438#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
439#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
440
441#ifdef __BIG_ENDIAN
442static int bits_to_user(unsigned long *bits, unsigned int maxbit,
443 unsigned int maxlen, void __user *p, int compat)
444{
445 int len, i;
446
447 if (compat) {
448 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
449 if (len > maxlen)
450 len = maxlen;
451
452 for (i = 0; i < len / sizeof(compat_long_t); i++)
453 if (copy_to_user((compat_long_t __user *) p + i,
454 (compat_long_t *) bits +
455 i + 1 - ((i % 2) << 1),
456 sizeof(compat_long_t)))
457 return -EFAULT;
458 } else {
459 len = BITS_TO_LONGS(maxbit) * sizeof(long);
460 if (len > maxlen)
461 len = maxlen;
462
463 if (copy_to_user(p, bits, len))
464 return -EFAULT;
465 }
466
467 return len;
468}
469#else
470static int bits_to_user(unsigned long *bits, unsigned int maxbit,
471 unsigned int maxlen, void __user *p, int compat)
472{
473 int len = compat ?
474 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
475 BITS_TO_LONGS(maxbit) * sizeof(long);
476
477 if (len > maxlen)
478 len = maxlen;
479
480 return copy_to_user(p, bits, len) ? -EFAULT : len;
481}
482#endif /* __BIG_ENDIAN */
483
484#else
485
486static int bits_to_user(unsigned long *bits, unsigned int maxbit,
487 unsigned int maxlen, void __user *p, int compat)
488{
489 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
490
491 if (len > maxlen)
492 len = maxlen;
493
494 return copy_to_user(p, bits, len) ? -EFAULT : len;
495}
496
497#endif /* CONFIG_COMPAT */
498
499static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
500{
501 int len;
502
503 if (!str)
504 return -ENOENT;
505
506 len = strlen(str) + 1;
507 if (len > maxlen)
508 len = maxlen;
509
510 return copy_to_user(p, str, len) ? -EFAULT : len;
511}
512
513#define OLD_KEY_MAX 0x1ff
514static int handle_eviocgbit(struct input_dev *dev,
515 unsigned int type, unsigned int size,
516 void __user *p, int compat_mode)
517{
518 static unsigned long keymax_warn_time;
519 unsigned long *bits;
520 int len;
521
522 switch (type) {
523
524 case 0: bits = dev->evbit; len = EV_MAX; break;
525 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
526 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
527 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
528 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
529 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
530 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
531 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
532 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
533 default: return -EINVAL;
534 }
535
536 /*
537 * Work around bugs in userspace programs that like to do
538 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
539 * should be in bytes, not in bits.
540 */
541 if (type == EV_KEY && size == OLD_KEY_MAX) {
542 len = OLD_KEY_MAX;
543 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
544 pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
545 "limiting output to %zu bytes. See "
546 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
547 OLD_KEY_MAX,
548 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
549 }
550
551 return bits_to_user(bits, len, size, p, compat_mode);
552}
553#undef OLD_KEY_MAX
554
555static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
556{
557 struct input_keymap_entry ke = {
558 .len = sizeof(unsigned int),
559 .flags = 0,
560 };
561 int __user *ip = (int __user *)p;
562 int error;
563
564 /* legacy case */
565 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
566 return -EFAULT;
567
568 error = input_get_keycode(dev, &ke);
569 if (error)
570 return error;
571
572 if (put_user(ke.keycode, ip + 1))
573 return -EFAULT;
574
575 return 0;
576}
577
578static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
579{
580 struct input_keymap_entry ke;
581 int error;
582
583 if (copy_from_user(&ke, p, sizeof(ke)))
584 return -EFAULT;
585
586 error = input_get_keycode(dev, &ke);
587 if (error)
588 return error;
589
590 if (copy_to_user(p, &ke, sizeof(ke)))
591 return -EFAULT;
592
593 return 0;
594}
595
596static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
597{
598 struct input_keymap_entry ke = {
599 .len = sizeof(unsigned int),
600 .flags = 0,
601 };
602 int __user *ip = (int __user *)p;
603
604 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
605 return -EFAULT;
606
607 if (get_user(ke.keycode, ip + 1))
608 return -EFAULT;
609
610 return input_set_keycode(dev, &ke);
611}
612
613static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
614{
615 struct input_keymap_entry ke;
616
617 if (copy_from_user(&ke, p, sizeof(ke)))
618 return -EFAULT;
619
620 if (ke.len > sizeof(ke.scancode))
621 return -EINVAL;
622
623 return input_set_keycode(dev, &ke);
624}
625
626static long evdev_do_ioctl(struct file *file, unsigned int cmd,
627 void __user *p, int compat_mode)
628{
629 struct evdev_client *client = file->private_data;
630 struct evdev *evdev = client->evdev;
631 struct input_dev *dev = evdev->handle.dev;
632 struct input_absinfo abs;
633 struct ff_effect effect;
634 int __user *ip = (int __user *)p;
635 unsigned int i, t, u, v;
636 unsigned int size;
637 int error;
638
639 /* First we check for fixed-length commands */
640 switch (cmd) {
641
642 case EVIOCGVERSION:
643 return put_user(EV_VERSION, ip);
644
645 case EVIOCGID:
646 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
647 return -EFAULT;
648 return 0;
649
650 case EVIOCGREP:
651 if (!test_bit(EV_REP, dev->evbit))
652 return -ENOSYS;
653 if (put_user(dev->rep[REP_DELAY], ip))
654 return -EFAULT;
655 if (put_user(dev->rep[REP_PERIOD], ip + 1))
656 return -EFAULT;
657 return 0;
658
659 case EVIOCSREP:
660 if (!test_bit(EV_REP, dev->evbit))
661 return -ENOSYS;
662 if (get_user(u, ip))
663 return -EFAULT;
664 if (get_user(v, ip + 1))
665 return -EFAULT;
666
667 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
668 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
669
670 return 0;
671
672 case EVIOCRMFF:
673 return input_ff_erase(dev, (int)(unsigned long) p, file);
674
675 case EVIOCGEFFECTS:
676 i = test_bit(EV_FF, dev->evbit) ?
677 dev->ff->max_effects : 0;
678 if (put_user(i, ip))
679 return -EFAULT;
680 return 0;
681
682 case EVIOCGRAB:
683 if (p)
684 return evdev_grab(evdev, client);
685 else
686 return evdev_ungrab(evdev, client);
687
688 case EVIOCGKEYCODE:
689 return evdev_handle_get_keycode(dev, p);
690
691 case EVIOCSKEYCODE:
692 return evdev_handle_set_keycode(dev, p);
693
694 case EVIOCGKEYCODE_V2:
695 return evdev_handle_get_keycode_v2(dev, p);
696
697 case EVIOCSKEYCODE_V2:
698 return evdev_handle_set_keycode_v2(dev, p);
699 }
700
701 size = _IOC_SIZE(cmd);
702
703 /* Now check variable-length commands */
704#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
705 switch (EVIOC_MASK_SIZE(cmd)) {
706
707 case EVIOCGPROP(0):
708 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
709 size, p, compat_mode);
710
711 case EVIOCGKEY(0):
712 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
713
714 case EVIOCGLED(0):
715 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
716
717 case EVIOCGSND(0):
718 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
719
720 case EVIOCGSW(0):
721 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
722
723 case EVIOCGNAME(0):
724 return str_to_user(dev->name, size, p);
725
726 case EVIOCGPHYS(0):
727 return str_to_user(dev->phys, size, p);
728
729 case EVIOCGUNIQ(0):
730 return str_to_user(dev->uniq, size, p);
731
732 case EVIOC_MASK_SIZE(EVIOCSFF):
733 if (input_ff_effect_from_user(p, size, &effect))
734 return -EFAULT;
735
736 error = input_ff_upload(dev, &effect, file);
737
738 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
739 return -EFAULT;
740
741 return error;
742 }
743
744 /* Multi-number variable-length handlers */
745 if (_IOC_TYPE(cmd) != 'E')
746 return -EINVAL;
747
748 if (_IOC_DIR(cmd) == _IOC_READ) {
749
750 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
751 return handle_eviocgbit(dev,
752 _IOC_NR(cmd) & EV_MAX, size,
753 p, compat_mode);
754
755 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
756
757 if (!dev->absinfo)
758 return -EINVAL;
759
760 t = _IOC_NR(cmd) & ABS_MAX;
761 abs = dev->absinfo[t];
762
763 if (copy_to_user(p, &abs, min_t(size_t,
764 size, sizeof(struct input_absinfo))))
765 return -EFAULT;
766
767 return 0;
768 }
769 }
770
771 if (_IOC_DIR(cmd) == _IOC_WRITE) {
772
773 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
774
775 if (!dev->absinfo)
776 return -EINVAL;
777
778 t = _IOC_NR(cmd) & ABS_MAX;
779
780 if (copy_from_user(&abs, p, min_t(size_t,
781 size, sizeof(struct input_absinfo))))
782 return -EFAULT;
783
784 if (size < sizeof(struct input_absinfo))
785 abs.resolution = 0;
786
787 /* We can't change number of reserved MT slots */
788 if (t == ABS_MT_SLOT)
789 return -EINVAL;
790
791 /*
792 * Take event lock to ensure that we are not
793 * changing device parameters in the middle
794 * of event.
795 */
796 spin_lock_irq(&dev->event_lock);
797 dev->absinfo[t] = abs;
798 spin_unlock_irq(&dev->event_lock);
799
800 return 0;
801 }
802 }
803
804 return -EINVAL;
805}
806
807static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
808 void __user *p, int compat_mode)
809{
810 struct evdev_client *client = file->private_data;
811 struct evdev *evdev = client->evdev;
812 int retval;
813
814 retval = mutex_lock_interruptible(&evdev->mutex);
815 if (retval)
816 return retval;
817
818 if (!evdev->exist) {
819 retval = -ENODEV;
820 goto out;
821 }
822
823 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
824
825 out:
826 mutex_unlock(&evdev->mutex);
827 return retval;
828}
829
830static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
831{
832 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
833}
834
835#ifdef CONFIG_COMPAT
836static long evdev_ioctl_compat(struct file *file,
837 unsigned int cmd, unsigned long arg)
838{
839 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
840}
841#endif
842
843static const struct file_operations evdev_fops = {
844 .owner = THIS_MODULE,
845 .read = evdev_read,
846 .write = evdev_write,
847 .poll = evdev_poll,
848 .open = evdev_open,
849 .release = evdev_release,
850 .unlocked_ioctl = evdev_ioctl,
851#ifdef CONFIG_COMPAT
852 .compat_ioctl = evdev_ioctl_compat,
853#endif
854 .fasync = evdev_fasync,
855 .flush = evdev_flush,
856 .llseek = no_llseek,
857};
858
859static int evdev_install_chrdev(struct evdev *evdev)
860{
861 /*
862 * No need to do any locking here as calls to connect and
863 * disconnect are serialized by the input core
864 */
865 evdev_table[evdev->minor] = evdev;
866 return 0;
867}
868
869static void evdev_remove_chrdev(struct evdev *evdev)
870{
871 /*
872 * Lock evdev table to prevent race with evdev_open()
873 */
874 mutex_lock(&evdev_table_mutex);
875 evdev_table[evdev->minor] = NULL;
876 mutex_unlock(&evdev_table_mutex);
877}
878
879/*
880 * Mark device non-existent. This disables writes, ioctls and
881 * prevents new users from opening the device. Already posted
882 * blocking reads will stay, however new ones will fail.
883 */
884static void evdev_mark_dead(struct evdev *evdev)
885{
886 mutex_lock(&evdev->mutex);
887 evdev->exist = false;
888 mutex_unlock(&evdev->mutex);
889}
890
891static void evdev_cleanup(struct evdev *evdev)
892{
893 struct input_handle *handle = &evdev->handle;
894
895 evdev_mark_dead(evdev);
896 evdev_hangup(evdev);
897 evdev_remove_chrdev(evdev);
898
899 /* evdev is marked dead so no one else accesses evdev->open */
900 if (evdev->open) {
901 input_flush_device(handle, NULL);
902 input_close_device(handle);
903 }
904}
905
906/*
907 * Create new evdev device. Note that input core serializes calls
908 * to connect and disconnect so we don't need to lock evdev_table here.
909 */
910static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
911 const struct input_device_id *id)
912{
913 struct evdev *evdev;
914 int minor;
915 int error;
916
917 for (minor = 0; minor < EVDEV_MINORS; minor++)
918 if (!evdev_table[minor])
919 break;
920
921 if (minor == EVDEV_MINORS) {
922 pr_err("no more free evdev devices\n");
923 return -ENFILE;
924 }
925
926 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
927 if (!evdev)
928 return -ENOMEM;
929
930 INIT_LIST_HEAD(&evdev->client_list);
931 spin_lock_init(&evdev->client_lock);
932 mutex_init(&evdev->mutex);
933 init_waitqueue_head(&evdev->wait);
934
935 dev_set_name(&evdev->dev, "event%d", minor);
936 evdev->exist = true;
937 evdev->minor = minor;
938
939 evdev->handle.dev = input_get_device(dev);
940 evdev->handle.name = dev_name(&evdev->dev);
941 evdev->handle.handler = handler;
942 evdev->handle.private = evdev;
943
944 evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
945 evdev->dev.class = &input_class;
946 evdev->dev.parent = &dev->dev;
947 evdev->dev.release = evdev_free;
948 device_initialize(&evdev->dev);
949
950 error = input_register_handle(&evdev->handle);
951 if (error)
952 goto err_free_evdev;
953
954 error = evdev_install_chrdev(evdev);
955 if (error)
956 goto err_unregister_handle;
957
958 error = device_add(&evdev->dev);
959 if (error)
960 goto err_cleanup_evdev;
961
962 return 0;
963
964 err_cleanup_evdev:
965 evdev_cleanup(evdev);
966 err_unregister_handle:
967 input_unregister_handle(&evdev->handle);
968 err_free_evdev:
969 put_device(&evdev->dev);
970 return error;
971}
972
973static void evdev_disconnect(struct input_handle *handle)
974{
975 struct evdev *evdev = handle->private;
976
977 device_del(&evdev->dev);
978 evdev_cleanup(evdev);
979 input_unregister_handle(handle);
980 put_device(&evdev->dev);
981}
982
983static const struct input_device_id evdev_ids[] = {
984 { .driver_info = 1 }, /* Matches all devices */
985 { }, /* Terminating zero entry */
986};
987
988MODULE_DEVICE_TABLE(input, evdev_ids);
989
990static struct input_handler evdev_handler = {
991 .event = evdev_event,
992 .connect = evdev_connect,
993 .disconnect = evdev_disconnect,
994 .fops = &evdev_fops,
995 .minor = EVDEV_MINOR_BASE,
996 .name = "evdev",
997 .id_table = evdev_ids,
998};
999
1000static int __init evdev_init(void)
1001{
1002 return input_register_handler(&evdev_handler);
1003}
1004
1005static void __exit evdev_exit(void)
1006{
1007 input_unregister_handler(&evdev_handler);
1008}
1009
1010module_init(evdev_init);
1011module_exit(evdev_exit);
1012
1013MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
1014MODULE_DESCRIPTION("Input driver event char devices");
1015MODULE_LICENSE("GPL");