projects/linux·blob v3.10-rc2 · refs

1068 lines · 24.0 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/mt.h>
24#include <linux/major.h>
25#include <linux/device.h>
26#include <linux/cdev.h>
27#include "input-compat.h"
28
29struct evdev {
30 int open;
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 struct cdev cdev;
39 bool exist;
40};
41
42struct evdev_client {
43 unsigned int head;
44 unsigned int tail;
45 unsigned int packet_head; /* [future] position of the first element of next packet */
46 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
47 struct fasync_struct *fasync;
48 struct evdev *evdev;
49 struct list_head node;
50 int clkid;
51 unsigned int bufsize;
52 struct input_event buffer[];
53};
54
55static void __pass_event(struct evdev_client *client,
56 const struct input_event *event)
57{
58 client->buffer[client->head++] = *event;
59 client->head &= client->bufsize - 1;
60
61 if (unlikely(client->head == client->tail)) {
62 /*
63 * This effectively "drops" all unconsumed events, leaving
64 * EV_SYN/SYN_DROPPED plus the newest event in the queue.
65 */
66 client->tail = (client->head - 2) & (client->bufsize - 1);
67
68 client->buffer[client->tail].time = event->time;
69 client->buffer[client->tail].type = EV_SYN;
70 client->buffer[client->tail].code = SYN_DROPPED;
71 client->buffer[client->tail].value = 0;
72
73 client->packet_head = client->tail;
74 }
75
76 if (event->type == EV_SYN && event->code == SYN_REPORT) {
77 client->packet_head = client->head;
78 kill_fasync(&client->fasync, SIGIO, POLL_IN);
79 }
80}
81
82static void evdev_pass_values(struct evdev_client *client,
83 const struct input_value *vals, unsigned int count,
84 ktime_t mono, ktime_t real)
85{
86 struct evdev *evdev = client->evdev;
87 const struct input_value *v;
88 struct input_event event;
89 bool wakeup = false;
90
91 event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
92 mono : real);
93
94 /* Interrupts are disabled, just acquire the lock. */
95 spin_lock(&client->buffer_lock);
96
97 for (v = vals; v != vals + count; v++) {
98 event.type = v->type;
99 event.code = v->code;
100 event.value = v->value;
101 __pass_event(client, &event);
102 if (v->type == EV_SYN && v->code == SYN_REPORT)
103 wakeup = true;
104 }
105
106 spin_unlock(&client->buffer_lock);
107
108 if (wakeup)
109 wake_up_interruptible(&evdev->wait);
110}
111
112/*
113 * Pass incoming events to all connected clients.
114 */
115static void evdev_events(struct input_handle *handle,
116 const struct input_value *vals, unsigned int count)
117{
118 struct evdev *evdev = handle->private;
119 struct evdev_client *client;
120 ktime_t time_mono, time_real;
121
122 time_mono = ktime_get();
123 time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
124
125 rcu_read_lock();
126
127 client = rcu_dereference(evdev->grab);
128
129 if (client)
130 evdev_pass_values(client, vals, count, time_mono, time_real);
131 else
132 list_for_each_entry_rcu(client, &evdev->client_list, node)
133 evdev_pass_values(client, vals, count,
134 time_mono, time_real);
135
136 rcu_read_unlock();
137}
138
139/*
140 * Pass incoming event to all connected clients.
141 */
142static void evdev_event(struct input_handle *handle,
143 unsigned int type, unsigned int code, int value)
144{
145 struct input_value vals[] = { { type, code, value } };
146
147 evdev_events(handle, vals, 1);
148}
149
150static int evdev_fasync(int fd, struct file *file, int on)
151{
152 struct evdev_client *client = file->private_data;
153
154 return fasync_helper(fd, file, on, &client->fasync);
155}
156
157static int evdev_flush(struct file *file, fl_owner_t id)
158{
159 struct evdev_client *client = file->private_data;
160 struct evdev *evdev = client->evdev;
161 int retval;
162
163 retval = mutex_lock_interruptible(&evdev->mutex);
164 if (retval)
165 return retval;
166
167 if (!evdev->exist)
168 retval = -ENODEV;
169 else
170 retval = input_flush_device(&evdev->handle, file);
171
172 mutex_unlock(&evdev->mutex);
173 return retval;
174}
175
176static void evdev_free(struct device *dev)
177{
178 struct evdev *evdev = container_of(dev, struct evdev, dev);
179
180 input_put_device(evdev->handle.dev);
181 kfree(evdev);
182}
183
184/*
185 * Grabs an event device (along with underlying input device).
186 * This function is called with evdev->mutex taken.
187 */
188static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
189{
190 int error;
191
192 if (evdev->grab)
193 return -EBUSY;
194
195 error = input_grab_device(&evdev->handle);
196 if (error)
197 return error;
198
199 rcu_assign_pointer(evdev->grab, client);
200
201 return 0;
202}
203
204static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
205{
206 struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
207 lockdep_is_held(&evdev->mutex));
208
209 if (grab != client)
210 return -EINVAL;
211
212 rcu_assign_pointer(evdev->grab, NULL);
213 synchronize_rcu();
214 input_release_device(&evdev->handle);
215
216 return 0;
217}
218
219static void evdev_attach_client(struct evdev *evdev,
220 struct evdev_client *client)
221{
222 spin_lock(&evdev->client_lock);
223 list_add_tail_rcu(&client->node, &evdev->client_list);
224 spin_unlock(&evdev->client_lock);
225}
226
227static void evdev_detach_client(struct evdev *evdev,
228 struct evdev_client *client)
229{
230 spin_lock(&evdev->client_lock);
231 list_del_rcu(&client->node);
232 spin_unlock(&evdev->client_lock);
233 synchronize_rcu();
234}
235
236static int evdev_open_device(struct evdev *evdev)
237{
238 int retval;
239
240 retval = mutex_lock_interruptible(&evdev->mutex);
241 if (retval)
242 return retval;
243
244 if (!evdev->exist)
245 retval = -ENODEV;
246 else if (!evdev->open++) {
247 retval = input_open_device(&evdev->handle);
248 if (retval)
249 evdev->open--;
250 }
251
252 mutex_unlock(&evdev->mutex);
253 return retval;
254}
255
256static void evdev_close_device(struct evdev *evdev)
257{
258 mutex_lock(&evdev->mutex);
259
260 if (evdev->exist && !--evdev->open)
261 input_close_device(&evdev->handle);
262
263 mutex_unlock(&evdev->mutex);
264}
265
266/*
267 * Wake up users waiting for IO so they can disconnect from
268 * dead device.
269 */
270static void evdev_hangup(struct evdev *evdev)
271{
272 struct evdev_client *client;
273
274 spin_lock(&evdev->client_lock);
275 list_for_each_entry(client, &evdev->client_list, node)
276 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
277 spin_unlock(&evdev->client_lock);
278
279 wake_up_interruptible(&evdev->wait);
280}
281
282static int evdev_release(struct inode *inode, struct file *file)
283{
284 struct evdev_client *client = file->private_data;
285 struct evdev *evdev = client->evdev;
286
287 mutex_lock(&evdev->mutex);
288 evdev_ungrab(evdev, client);
289 mutex_unlock(&evdev->mutex);
290
291 evdev_detach_client(evdev, client);
292 kfree(client);
293
294 evdev_close_device(evdev);
295
296 return 0;
297}
298
299static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
300{
301 unsigned int n_events =
302 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
303 EVDEV_MIN_BUFFER_SIZE);
304
305 return roundup_pow_of_two(n_events);
306}
307
308static int evdev_open(struct inode *inode, struct file *file)
309{
310 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
311 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
312 struct evdev_client *client;
313 int error;
314
315 client = kzalloc(sizeof(struct evdev_client) +
316 bufsize * sizeof(struct input_event),
317 GFP_KERNEL);
318 if (!client)
319 return -ENOMEM;
320
321 client->bufsize = bufsize;
322 spin_lock_init(&client->buffer_lock);
323 client->evdev = evdev;
324 evdev_attach_client(evdev, client);
325
326 error = evdev_open_device(evdev);
327 if (error)
328 goto err_free_client;
329
330 file->private_data = client;
331 nonseekable_open(inode, file);
332
333 return 0;
334
335 err_free_client:
336 evdev_detach_client(evdev, client);
337 kfree(client);
338 return error;
339}
340
341static ssize_t evdev_write(struct file *file, const char __user *buffer,
342 size_t count, loff_t *ppos)
343{
344 struct evdev_client *client = file->private_data;
345 struct evdev *evdev = client->evdev;
346 struct input_event event;
347 int retval = 0;
348
349 if (count != 0 && count < input_event_size())
350 return -EINVAL;
351
352 retval = mutex_lock_interruptible(&evdev->mutex);
353 if (retval)
354 return retval;
355
356 if (!evdev->exist) {
357 retval = -ENODEV;
358 goto out;
359 }
360
361 while (retval + input_event_size() <= count) {
362
363 if (input_event_from_user(buffer + retval, &event)) {
364 retval = -EFAULT;
365 goto out;
366 }
367 retval += input_event_size();
368
369 input_inject_event(&evdev->handle,
370 event.type, event.code, event.value);
371 }
372
373 out:
374 mutex_unlock(&evdev->mutex);
375 return retval;
376}
377
378static int evdev_fetch_next_event(struct evdev_client *client,
379 struct input_event *event)
380{
381 int have_event;
382
383 spin_lock_irq(&client->buffer_lock);
384
385 have_event = client->packet_head != client->tail;
386 if (have_event) {
387 *event = client->buffer[client->tail++];
388 client->tail &= client->bufsize - 1;
389 }
390
391 spin_unlock_irq(&client->buffer_lock);
392
393 return have_event;
394}
395
396static ssize_t evdev_read(struct file *file, char __user *buffer,
397 size_t count, loff_t *ppos)
398{
399 struct evdev_client *client = file->private_data;
400 struct evdev *evdev = client->evdev;
401 struct input_event event;
402 size_t read = 0;
403 int error;
404
405 if (count != 0 && count < input_event_size())
406 return -EINVAL;
407
408 for (;;) {
409 if (!evdev->exist)
410 return -ENODEV;
411
412 if (client->packet_head == client->tail &&
413 (file->f_flags & O_NONBLOCK))
414 return -EAGAIN;
415
416 /*
417 * count == 0 is special - no IO is done but we check
418 * for error conditions (see above).
419 */
420 if (count == 0)
421 break;
422
423 while (read + input_event_size() <= count &&
424 evdev_fetch_next_event(client, &event)) {
425
426 if (input_event_to_user(buffer + read, &event))
427 return -EFAULT;
428
429 read += input_event_size();
430 }
431
432 if (read)
433 break;
434
435 if (!(file->f_flags & O_NONBLOCK)) {
436 error = wait_event_interruptible(evdev->wait,
437 client->packet_head != client->tail ||
438 !evdev->exist);
439 if (error)
440 return error;
441 }
442 }
443
444 return read;
445}
446
447/* No kernel lock - fine */
448static unsigned int evdev_poll(struct file *file, poll_table *wait)
449{
450 struct evdev_client *client = file->private_data;
451 struct evdev *evdev = client->evdev;
452 unsigned int mask;
453
454 poll_wait(file, &evdev->wait, wait);
455
456 mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
457 if (client->packet_head != client->tail)
458 mask |= POLLIN | POLLRDNORM;
459
460 return mask;
461}
462
463#ifdef CONFIG_COMPAT
464
465#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
466#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
467
468#ifdef __BIG_ENDIAN
469static int bits_to_user(unsigned long *bits, unsigned int maxbit,
470 unsigned int maxlen, void __user *p, int compat)
471{
472 int len, i;
473
474 if (compat) {
475 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
476 if (len > maxlen)
477 len = maxlen;
478
479 for (i = 0; i < len / sizeof(compat_long_t); i++)
480 if (copy_to_user((compat_long_t __user *) p + i,
481 (compat_long_t *) bits +
482 i + 1 - ((i % 2) << 1),
483 sizeof(compat_long_t)))
484 return -EFAULT;
485 } else {
486 len = BITS_TO_LONGS(maxbit) * sizeof(long);
487 if (len > maxlen)
488 len = maxlen;
489
490 if (copy_to_user(p, bits, len))
491 return -EFAULT;
492 }
493
494 return len;
495}
496#else
497static int bits_to_user(unsigned long *bits, unsigned int maxbit,
498 unsigned int maxlen, void __user *p, int compat)
499{
500 int len = compat ?
501 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
502 BITS_TO_LONGS(maxbit) * sizeof(long);
503
504 if (len > maxlen)
505 len = maxlen;
506
507 return copy_to_user(p, bits, len) ? -EFAULT : len;
508}
509#endif /* __BIG_ENDIAN */
510
511#else
512
513static int bits_to_user(unsigned long *bits, unsigned int maxbit,
514 unsigned int maxlen, void __user *p, int compat)
515{
516 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
517
518 if (len > maxlen)
519 len = maxlen;
520
521 return copy_to_user(p, bits, len) ? -EFAULT : len;
522}
523
524#endif /* CONFIG_COMPAT */
525
526static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
527{
528 int len;
529
530 if (!str)
531 return -ENOENT;
532
533 len = strlen(str) + 1;
534 if (len > maxlen)
535 len = maxlen;
536
537 return copy_to_user(p, str, len) ? -EFAULT : len;
538}
539
540#define OLD_KEY_MAX 0x1ff
541static int handle_eviocgbit(struct input_dev *dev,
542 unsigned int type, unsigned int size,
543 void __user *p, int compat_mode)
544{
545 static unsigned long keymax_warn_time;
546 unsigned long *bits;
547 int len;
548
549 switch (type) {
550
551 case 0: bits = dev->evbit; len = EV_MAX; break;
552 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
553 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
554 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
555 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
556 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
557 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
558 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
559 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
560 default: return -EINVAL;
561 }
562
563 /*
564 * Work around bugs in userspace programs that like to do
565 * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
566 * should be in bytes, not in bits.
567 */
568 if (type == EV_KEY && size == OLD_KEY_MAX) {
569 len = OLD_KEY_MAX;
570 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
571 pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
572 "limiting output to %zu bytes. See "
573 "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
574 OLD_KEY_MAX,
575 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
576 }
577
578 return bits_to_user(bits, len, size, p, compat_mode);
579}
580#undef OLD_KEY_MAX
581
582static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
583{
584 struct input_keymap_entry ke = {
585 .len = sizeof(unsigned int),
586 .flags = 0,
587 };
588 int __user *ip = (int __user *)p;
589 int error;
590
591 /* legacy case */
592 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
593 return -EFAULT;
594
595 error = input_get_keycode(dev, &ke);
596 if (error)
597 return error;
598
599 if (put_user(ke.keycode, ip + 1))
600 return -EFAULT;
601
602 return 0;
603}
604
605static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
606{
607 struct input_keymap_entry ke;
608 int error;
609
610 if (copy_from_user(&ke, p, sizeof(ke)))
611 return -EFAULT;
612
613 error = input_get_keycode(dev, &ke);
614 if (error)
615 return error;
616
617 if (copy_to_user(p, &ke, sizeof(ke)))
618 return -EFAULT;
619
620 return 0;
621}
622
623static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
624{
625 struct input_keymap_entry ke = {
626 .len = sizeof(unsigned int),
627 .flags = 0,
628 };
629 int __user *ip = (int __user *)p;
630
631 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
632 return -EFAULT;
633
634 if (get_user(ke.keycode, ip + 1))
635 return -EFAULT;
636
637 return input_set_keycode(dev, &ke);
638}
639
640static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
641{
642 struct input_keymap_entry ke;
643
644 if (copy_from_user(&ke, p, sizeof(ke)))
645 return -EFAULT;
646
647 if (ke.len > sizeof(ke.scancode))
648 return -EINVAL;
649
650 return input_set_keycode(dev, &ke);
651}
652
653static int evdev_handle_mt_request(struct input_dev *dev,
654 unsigned int size,
655 int __user *ip)
656{
657 const struct input_mt *mt = dev->mt;
658 unsigned int code;
659 int max_slots;
660 int i;
661
662 if (get_user(code, &ip[0]))
663 return -EFAULT;
664 if (!mt || !input_is_mt_value(code))
665 return -EINVAL;
666
667 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
668 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
669 int value = input_mt_get_value(&mt->slots[i], code);
670 if (put_user(value, &ip[1 + i]))
671 return -EFAULT;
672 }
673
674 return 0;
675}
676
677static long evdev_do_ioctl(struct file *file, unsigned int cmd,
678 void __user *p, int compat_mode)
679{
680 struct evdev_client *client = file->private_data;
681 struct evdev *evdev = client->evdev;
682 struct input_dev *dev = evdev->handle.dev;
683 struct input_absinfo abs;
684 struct ff_effect effect;
685 int __user *ip = (int __user *)p;
686 unsigned int i, t, u, v;
687 unsigned int size;
688 int error;
689
690 /* First we check for fixed-length commands */
691 switch (cmd) {
692
693 case EVIOCGVERSION:
694 return put_user(EV_VERSION, ip);
695
696 case EVIOCGID:
697 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
698 return -EFAULT;
699 return 0;
700
701 case EVIOCGREP:
702 if (!test_bit(EV_REP, dev->evbit))
703 return -ENOSYS;
704 if (put_user(dev->rep[REP_DELAY], ip))
705 return -EFAULT;
706 if (put_user(dev->rep[REP_PERIOD], ip + 1))
707 return -EFAULT;
708 return 0;
709
710 case EVIOCSREP:
711 if (!test_bit(EV_REP, dev->evbit))
712 return -ENOSYS;
713 if (get_user(u, ip))
714 return -EFAULT;
715 if (get_user(v, ip + 1))
716 return -EFAULT;
717
718 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
719 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
720
721 return 0;
722
723 case EVIOCRMFF:
724 return input_ff_erase(dev, (int)(unsigned long) p, file);
725
726 case EVIOCGEFFECTS:
727 i = test_bit(EV_FF, dev->evbit) ?
728 dev->ff->max_effects : 0;
729 if (put_user(i, ip))
730 return -EFAULT;
731 return 0;
732
733 case EVIOCGRAB:
734 if (p)
735 return evdev_grab(evdev, client);
736 else
737 return evdev_ungrab(evdev, client);
738
739 case EVIOCSCLOCKID:
740 if (copy_from_user(&i, p, sizeof(unsigned int)))
741 return -EFAULT;
742 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
743 return -EINVAL;
744 client->clkid = i;
745 return 0;
746
747 case EVIOCGKEYCODE:
748 return evdev_handle_get_keycode(dev, p);
749
750 case EVIOCSKEYCODE:
751 return evdev_handle_set_keycode(dev, p);
752
753 case EVIOCGKEYCODE_V2:
754 return evdev_handle_get_keycode_v2(dev, p);
755
756 case EVIOCSKEYCODE_V2:
757 return evdev_handle_set_keycode_v2(dev, p);
758 }
759
760 size = _IOC_SIZE(cmd);
761
762 /* Now check variable-length commands */
763#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
764 switch (EVIOC_MASK_SIZE(cmd)) {
765
766 case EVIOCGPROP(0):
767 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
768 size, p, compat_mode);
769
770 case EVIOCGMTSLOTS(0):
771 return evdev_handle_mt_request(dev, size, ip);
772
773 case EVIOCGKEY(0):
774 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
775
776 case EVIOCGLED(0):
777 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
778
779 case EVIOCGSND(0):
780 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
781
782 case EVIOCGSW(0):
783 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
784
785 case EVIOCGNAME(0):
786 return str_to_user(dev->name, size, p);
787
788 case EVIOCGPHYS(0):
789 return str_to_user(dev->phys, size, p);
790
791 case EVIOCGUNIQ(0):
792 return str_to_user(dev->uniq, size, p);
793
794 case EVIOC_MASK_SIZE(EVIOCSFF):
795 if (input_ff_effect_from_user(p, size, &effect))
796 return -EFAULT;
797
798 error = input_ff_upload(dev, &effect, file);
799
800 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
801 return -EFAULT;
802
803 return error;
804 }
805
806 /* Multi-number variable-length handlers */
807 if (_IOC_TYPE(cmd) != 'E')
808 return -EINVAL;
809
810 if (_IOC_DIR(cmd) == _IOC_READ) {
811
812 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
813 return handle_eviocgbit(dev,
814 _IOC_NR(cmd) & EV_MAX, size,
815 p, compat_mode);
816
817 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
818
819 if (!dev->absinfo)
820 return -EINVAL;
821
822 t = _IOC_NR(cmd) & ABS_MAX;
823 abs = dev->absinfo[t];
824
825 if (copy_to_user(p, &abs, min_t(size_t,
826 size, sizeof(struct input_absinfo))))
827 return -EFAULT;
828
829 return 0;
830 }
831 }
832
833 if (_IOC_DIR(cmd) == _IOC_WRITE) {
834
835 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
836
837 if (!dev->absinfo)
838 return -EINVAL;
839
840 t = _IOC_NR(cmd) & ABS_MAX;
841
842 if (copy_from_user(&abs, p, min_t(size_t,
843 size, sizeof(struct input_absinfo))))
844 return -EFAULT;
845
846 if (size < sizeof(struct input_absinfo))
847 abs.resolution = 0;
848
849 /* We can't change number of reserved MT slots */
850 if (t == ABS_MT_SLOT)
851 return -EINVAL;
852
853 /*
854 * Take event lock to ensure that we are not
855 * changing device parameters in the middle
856 * of event.
857 */
858 spin_lock_irq(&dev->event_lock);
859 dev->absinfo[t] = abs;
860 spin_unlock_irq(&dev->event_lock);
861
862 return 0;
863 }
864 }
865
866 return -EINVAL;
867}
868
869static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
870 void __user *p, int compat_mode)
871{
872 struct evdev_client *client = file->private_data;
873 struct evdev *evdev = client->evdev;
874 int retval;
875
876 retval = mutex_lock_interruptible(&evdev->mutex);
877 if (retval)
878 return retval;
879
880 if (!evdev->exist) {
881 retval = -ENODEV;
882 goto out;
883 }
884
885 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
886
887 out:
888 mutex_unlock(&evdev->mutex);
889 return retval;
890}
891
892static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
893{
894 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
895}
896
897#ifdef CONFIG_COMPAT
898static long evdev_ioctl_compat(struct file *file,
899 unsigned int cmd, unsigned long arg)
900{
901 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
902}
903#endif
904
905static const struct file_operations evdev_fops = {
906 .owner = THIS_MODULE,
907 .read = evdev_read,
908 .write = evdev_write,
909 .poll = evdev_poll,
910 .open = evdev_open,
911 .release = evdev_release,
912 .unlocked_ioctl = evdev_ioctl,
913#ifdef CONFIG_COMPAT
914 .compat_ioctl = evdev_ioctl_compat,
915#endif
916 .fasync = evdev_fasync,
917 .flush = evdev_flush,
918 .llseek = no_llseek,
919};
920
921/*
922 * Mark device non-existent. This disables writes, ioctls and
923 * prevents new users from opening the device. Already posted
924 * blocking reads will stay, however new ones will fail.
925 */
926static void evdev_mark_dead(struct evdev *evdev)
927{
928 mutex_lock(&evdev->mutex);
929 evdev->exist = false;
930 mutex_unlock(&evdev->mutex);
931}
932
933static void evdev_cleanup(struct evdev *evdev)
934{
935 struct input_handle *handle = &evdev->handle;
936
937 evdev_mark_dead(evdev);
938 evdev_hangup(evdev);
939
940 cdev_del(&evdev->cdev);
941
942 /* evdev is marked dead so no one else accesses evdev->open */
943 if (evdev->open) {
944 input_flush_device(handle, NULL);
945 input_close_device(handle);
946 }
947}
948
949/*
950 * Create new evdev device. Note that input core serializes calls
951 * to connect and disconnect.
952 */
953static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
954 const struct input_device_id *id)
955{
956 struct evdev *evdev;
957 int minor;
958 int dev_no;
959 int error;
960
961 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
962 if (minor < 0) {
963 error = minor;
964 pr_err("failed to reserve new minor: %d\n", error);
965 return error;
966 }
967
968 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
969 if (!evdev) {
970 error = -ENOMEM;
971 goto err_free_minor;
972 }
973
974 INIT_LIST_HEAD(&evdev->client_list);
975 spin_lock_init(&evdev->client_lock);
976 mutex_init(&evdev->mutex);
977 init_waitqueue_head(&evdev->wait);
978 evdev->exist = true;
979
980 dev_no = minor;
981 /* Normalize device number if it falls into legacy range */
982 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
983 dev_no -= EVDEV_MINOR_BASE;
984 dev_set_name(&evdev->dev, "event%d", dev_no);
985
986 evdev->handle.dev = input_get_device(dev);
987 evdev->handle.name = dev_name(&evdev->dev);
988 evdev->handle.handler = handler;
989 evdev->handle.private = evdev;
990
991 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
992 evdev->dev.class = &input_class;
993 evdev->dev.parent = &dev->dev;
994 evdev->dev.release = evdev_free;
995 device_initialize(&evdev->dev);
996
997 error = input_register_handle(&evdev->handle);
998 if (error)
999 goto err_free_evdev;
1000
1001 cdev_init(&evdev->cdev, &evdev_fops);
1002 evdev->cdev.kobj.parent = &evdev->dev.kobj;
1003 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1004 if (error)
1005 goto err_unregister_handle;
1006
1007 error = device_add(&evdev->dev);
1008 if (error)
1009 goto err_cleanup_evdev;
1010
1011 return 0;
1012
1013 err_cleanup_evdev:
1014 evdev_cleanup(evdev);
1015 err_unregister_handle:
1016 input_unregister_handle(&evdev->handle);
1017 err_free_evdev:
1018 put_device(&evdev->dev);
1019 err_free_minor:
1020 input_free_minor(minor);
1021 return error;
1022}
1023
1024static void evdev_disconnect(struct input_handle *handle)
1025{
1026 struct evdev *evdev = handle->private;
1027
1028 device_del(&evdev->dev);
1029 evdev_cleanup(evdev);
1030 input_free_minor(MINOR(evdev->dev.devt));
1031 input_unregister_handle(handle);
1032 put_device(&evdev->dev);
1033}
1034
1035static const struct input_device_id evdev_ids[] = {
1036 { .driver_info = 1 }, /* Matches all devices */
1037 { }, /* Terminating zero entry */
1038};
1039
1040MODULE_DEVICE_TABLE(input, evdev_ids);
1041
1042static struct input_handler evdev_handler = {
1043 .event = evdev_event,
1044 .events = evdev_events,
1045 .connect = evdev_connect,
1046 .disconnect = evdev_disconnect,
1047 .legacy_minors = true,
1048 .minor = EVDEV_MINOR_BASE,
1049 .name = "evdev",
1050 .id_table = evdev_ids,
1051};
1052
1053static int __init evdev_init(void)
1054{
1055 return input_register_handler(&evdev_handler);
1056}
1057
1058static void __exit evdev_exit(void)
1059{
1060 input_unregister_handler(&evdev_handler);
1061}
1062
1063module_init(evdev_init);
1064module_exit(evdev_exit);
1065
1066MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
1067MODULE_DESCRIPTION("Input driver event char devices");
1068MODULE_LICENSE("GPL");