projects/linux·blob v4.1-rc4 · refs

1261 lines · 28.3 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/vmalloc.h>
22#include <linux/mm.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/input/mt.h>
26#include <linux/major.h>
27#include <linux/device.h>
28#include <linux/cdev.h>
29#include "input-compat.h"
30
31enum evdev_clock_type {
32 EV_CLK_REAL = 0,
33 EV_CLK_MONO,
34 EV_CLK_BOOT,
35 EV_CLK_MAX
36};
37
38struct evdev {
39 int open;
40 struct input_handle handle;
41 wait_queue_head_t wait;
42 struct evdev_client __rcu *grab;
43 struct list_head client_list;
44 spinlock_t client_lock; /* protects client_list */
45 struct mutex mutex;
46 struct device dev;
47 struct cdev cdev;
48 bool exist;
49};
50
51struct evdev_client {
52 unsigned int head;
53 unsigned int tail;
54 unsigned int packet_head; /* [future] position of the first element of next packet */
55 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
56 struct fasync_struct *fasync;
57 struct evdev *evdev;
58 struct list_head node;
59 int clk_type;
60 bool revoked;
61 unsigned int bufsize;
62 struct input_event buffer[];
63};
64
65/* flush queued events of type @type, caller must hold client->buffer_lock */
66static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
67{
68 unsigned int i, head, num;
69 unsigned int mask = client->bufsize - 1;
70 bool is_report;
71 struct input_event *ev;
72
73 BUG_ON(type == EV_SYN);
74
75 head = client->tail;
76 client->packet_head = client->tail;
77
78 /* init to 1 so a leading SYN_REPORT will not be dropped */
79 num = 1;
80
81 for (i = client->tail; i != client->head; i = (i + 1) & mask) {
82 ev = &client->buffer[i];
83 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
84
85 if (ev->type == type) {
86 /* drop matched entry */
87 continue;
88 } else if (is_report && !num) {
89 /* drop empty SYN_REPORT groups */
90 continue;
91 } else if (head != i) {
92 /* move entry to fill the gap */
93 client->buffer[head].time = ev->time;
94 client->buffer[head].type = ev->type;
95 client->buffer[head].code = ev->code;
96 client->buffer[head].value = ev->value;
97 }
98
99 num++;
100 head = (head + 1) & mask;
101
102 if (is_report) {
103 num = 0;
104 client->packet_head = head;
105 }
106 }
107
108 client->head = head;
109}
110
111static void __evdev_queue_syn_dropped(struct evdev_client *client)
112{
113 struct input_event ev;
114 ktime_t time;
115
116 time = client->clk_type == EV_CLK_REAL ?
117 ktime_get_real() :
118 client->clk_type == EV_CLK_MONO ?
119 ktime_get() :
120 ktime_get_boottime();
121
122 ev.time = ktime_to_timeval(time);
123 ev.type = EV_SYN;
124 ev.code = SYN_DROPPED;
125 ev.value = 0;
126
127 client->buffer[client->head++] = ev;
128 client->head &= client->bufsize - 1;
129
130 if (unlikely(client->head == client->tail)) {
131 /* drop queue but keep our SYN_DROPPED event */
132 client->tail = (client->head - 1) & (client->bufsize - 1);
133 client->packet_head = client->tail;
134 }
135}
136
137static void evdev_queue_syn_dropped(struct evdev_client *client)
138{
139 unsigned long flags;
140
141 spin_lock_irqsave(&client->buffer_lock, flags);
142 __evdev_queue_syn_dropped(client);
143 spin_unlock_irqrestore(&client->buffer_lock, flags);
144}
145
146static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
147{
148 unsigned long flags;
149
150 if (client->clk_type == clkid)
151 return 0;
152
153 switch (clkid) {
154
155 case CLOCK_REALTIME:
156 client->clk_type = EV_CLK_REAL;
157 break;
158 case CLOCK_MONOTONIC:
159 client->clk_type = EV_CLK_MONO;
160 break;
161 case CLOCK_BOOTTIME:
162 client->clk_type = EV_CLK_BOOT;
163 break;
164 default:
165 return -EINVAL;
166 }
167
168 /*
169 * Flush pending events and queue SYN_DROPPED event,
170 * but only if the queue is not empty.
171 */
172 spin_lock_irqsave(&client->buffer_lock, flags);
173
174 if (client->head != client->tail) {
175 client->packet_head = client->head = client->tail;
176 __evdev_queue_syn_dropped(client);
177 }
178
179 spin_unlock_irqrestore(&client->buffer_lock, flags);
180
181 return 0;
182}
183
184static void __pass_event(struct evdev_client *client,
185 const struct input_event *event)
186{
187 client->buffer[client->head++] = *event;
188 client->head &= client->bufsize - 1;
189
190 if (unlikely(client->head == client->tail)) {
191 /*
192 * This effectively "drops" all unconsumed events, leaving
193 * EV_SYN/SYN_DROPPED plus the newest event in the queue.
194 */
195 client->tail = (client->head - 2) & (client->bufsize - 1);
196
197 client->buffer[client->tail].time = event->time;
198 client->buffer[client->tail].type = EV_SYN;
199 client->buffer[client->tail].code = SYN_DROPPED;
200 client->buffer[client->tail].value = 0;
201
202 client->packet_head = client->tail;
203 }
204
205 if (event->type == EV_SYN && event->code == SYN_REPORT) {
206 client->packet_head = client->head;
207 kill_fasync(&client->fasync, SIGIO, POLL_IN);
208 }
209}
210
211static void evdev_pass_values(struct evdev_client *client,
212 const struct input_value *vals, unsigned int count,
213 ktime_t *ev_time)
214{
215 struct evdev *evdev = client->evdev;
216 const struct input_value *v;
217 struct input_event event;
218 bool wakeup = false;
219
220 if (client->revoked)
221 return;
222
223 event.time = ktime_to_timeval(ev_time[client->clk_type]);
224
225 /* Interrupts are disabled, just acquire the lock. */
226 spin_lock(&client->buffer_lock);
227
228 for (v = vals; v != vals + count; v++) {
229 event.type = v->type;
230 event.code = v->code;
231 event.value = v->value;
232 __pass_event(client, &event);
233 if (v->type == EV_SYN && v->code == SYN_REPORT)
234 wakeup = true;
235 }
236
237 spin_unlock(&client->buffer_lock);
238
239 if (wakeup)
240 wake_up_interruptible(&evdev->wait);
241}
242
243/*
244 * Pass incoming events to all connected clients.
245 */
246static void evdev_events(struct input_handle *handle,
247 const struct input_value *vals, unsigned int count)
248{
249 struct evdev *evdev = handle->private;
250 struct evdev_client *client;
251 ktime_t ev_time[EV_CLK_MAX];
252
253 ev_time[EV_CLK_MONO] = ktime_get();
254 ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
255 ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
256 TK_OFFS_BOOT);
257
258 rcu_read_lock();
259
260 client = rcu_dereference(evdev->grab);
261
262 if (client)
263 evdev_pass_values(client, vals, count, ev_time);
264 else
265 list_for_each_entry_rcu(client, &evdev->client_list, node)
266 evdev_pass_values(client, vals, count, ev_time);
267
268 rcu_read_unlock();
269}
270
271/*
272 * Pass incoming event to all connected clients.
273 */
274static void evdev_event(struct input_handle *handle,
275 unsigned int type, unsigned int code, int value)
276{
277 struct input_value vals[] = { { type, code, value } };
278
279 evdev_events(handle, vals, 1);
280}
281
282static int evdev_fasync(int fd, struct file *file, int on)
283{
284 struct evdev_client *client = file->private_data;
285
286 return fasync_helper(fd, file, on, &client->fasync);
287}
288
289static int evdev_flush(struct file *file, fl_owner_t id)
290{
291 struct evdev_client *client = file->private_data;
292 struct evdev *evdev = client->evdev;
293 int retval;
294
295 retval = mutex_lock_interruptible(&evdev->mutex);
296 if (retval)
297 return retval;
298
299 if (!evdev->exist || client->revoked)
300 retval = -ENODEV;
301 else
302 retval = input_flush_device(&evdev->handle, file);
303
304 mutex_unlock(&evdev->mutex);
305 return retval;
306}
307
308static void evdev_free(struct device *dev)
309{
310 struct evdev *evdev = container_of(dev, struct evdev, dev);
311
312 input_put_device(evdev->handle.dev);
313 kfree(evdev);
314}
315
316/*
317 * Grabs an event device (along with underlying input device).
318 * This function is called with evdev->mutex taken.
319 */
320static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
321{
322 int error;
323
324 if (evdev->grab)
325 return -EBUSY;
326
327 error = input_grab_device(&evdev->handle);
328 if (error)
329 return error;
330
331 rcu_assign_pointer(evdev->grab, client);
332
333 return 0;
334}
335
336static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
337{
338 struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
339 lockdep_is_held(&evdev->mutex));
340
341 if (grab != client)
342 return -EINVAL;
343
344 rcu_assign_pointer(evdev->grab, NULL);
345 synchronize_rcu();
346 input_release_device(&evdev->handle);
347
348 return 0;
349}
350
351static void evdev_attach_client(struct evdev *evdev,
352 struct evdev_client *client)
353{
354 spin_lock(&evdev->client_lock);
355 list_add_tail_rcu(&client->node, &evdev->client_list);
356 spin_unlock(&evdev->client_lock);
357}
358
359static void evdev_detach_client(struct evdev *evdev,
360 struct evdev_client *client)
361{
362 spin_lock(&evdev->client_lock);
363 list_del_rcu(&client->node);
364 spin_unlock(&evdev->client_lock);
365 synchronize_rcu();
366}
367
368static int evdev_open_device(struct evdev *evdev)
369{
370 int retval;
371
372 retval = mutex_lock_interruptible(&evdev->mutex);
373 if (retval)
374 return retval;
375
376 if (!evdev->exist)
377 retval = -ENODEV;
378 else if (!evdev->open++) {
379 retval = input_open_device(&evdev->handle);
380 if (retval)
381 evdev->open--;
382 }
383
384 mutex_unlock(&evdev->mutex);
385 return retval;
386}
387
388static void evdev_close_device(struct evdev *evdev)
389{
390 mutex_lock(&evdev->mutex);
391
392 if (evdev->exist && !--evdev->open)
393 input_close_device(&evdev->handle);
394
395 mutex_unlock(&evdev->mutex);
396}
397
398/*
399 * Wake up users waiting for IO so they can disconnect from
400 * dead device.
401 */
402static void evdev_hangup(struct evdev *evdev)
403{
404 struct evdev_client *client;
405
406 spin_lock(&evdev->client_lock);
407 list_for_each_entry(client, &evdev->client_list, node)
408 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
409 spin_unlock(&evdev->client_lock);
410
411 wake_up_interruptible(&evdev->wait);
412}
413
414static int evdev_release(struct inode *inode, struct file *file)
415{
416 struct evdev_client *client = file->private_data;
417 struct evdev *evdev = client->evdev;
418
419 mutex_lock(&evdev->mutex);
420 evdev_ungrab(evdev, client);
421 mutex_unlock(&evdev->mutex);
422
423 evdev_detach_client(evdev, client);
424
425 if (is_vmalloc_addr(client))
426 vfree(client);
427 else
428 kfree(client);
429
430 evdev_close_device(evdev);
431
432 return 0;
433}
434
435static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
436{
437 unsigned int n_events =
438 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
439 EVDEV_MIN_BUFFER_SIZE);
440
441 return roundup_pow_of_two(n_events);
442}
443
444static int evdev_open(struct inode *inode, struct file *file)
445{
446 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
447 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
448 unsigned int size = sizeof(struct evdev_client) +
449 bufsize * sizeof(struct input_event);
450 struct evdev_client *client;
451 int error;
452
453 client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
454 if (!client)
455 client = vzalloc(size);
456 if (!client)
457 return -ENOMEM;
458
459 client->bufsize = bufsize;
460 spin_lock_init(&client->buffer_lock);
461 client->evdev = evdev;
462 evdev_attach_client(evdev, client);
463
464 error = evdev_open_device(evdev);
465 if (error)
466 goto err_free_client;
467
468 file->private_data = client;
469 nonseekable_open(inode, file);
470
471 return 0;
472
473 err_free_client:
474 evdev_detach_client(evdev, client);
475 kvfree(client);
476 return error;
477}
478
479static ssize_t evdev_write(struct file *file, const char __user *buffer,
480 size_t count, loff_t *ppos)
481{
482 struct evdev_client *client = file->private_data;
483 struct evdev *evdev = client->evdev;
484 struct input_event event;
485 int retval = 0;
486
487 if (count != 0 && count < input_event_size())
488 return -EINVAL;
489
490 retval = mutex_lock_interruptible(&evdev->mutex);
491 if (retval)
492 return retval;
493
494 if (!evdev->exist || client->revoked) {
495 retval = -ENODEV;
496 goto out;
497 }
498
499 while (retval + input_event_size() <= count) {
500
501 if (input_event_from_user(buffer + retval, &event)) {
502 retval = -EFAULT;
503 goto out;
504 }
505 retval += input_event_size();
506
507 input_inject_event(&evdev->handle,
508 event.type, event.code, event.value);
509 }
510
511 out:
512 mutex_unlock(&evdev->mutex);
513 return retval;
514}
515
516static int evdev_fetch_next_event(struct evdev_client *client,
517 struct input_event *event)
518{
519 int have_event;
520
521 spin_lock_irq(&client->buffer_lock);
522
523 have_event = client->packet_head != client->tail;
524 if (have_event) {
525 *event = client->buffer[client->tail++];
526 client->tail &= client->bufsize - 1;
527 }
528
529 spin_unlock_irq(&client->buffer_lock);
530
531 return have_event;
532}
533
534static ssize_t evdev_read(struct file *file, char __user *buffer,
535 size_t count, loff_t *ppos)
536{
537 struct evdev_client *client = file->private_data;
538 struct evdev *evdev = client->evdev;
539 struct input_event event;
540 size_t read = 0;
541 int error;
542
543 if (count != 0 && count < input_event_size())
544 return -EINVAL;
545
546 for (;;) {
547 if (!evdev->exist || client->revoked)
548 return -ENODEV;
549
550 if (client->packet_head == client->tail &&
551 (file->f_flags & O_NONBLOCK))
552 return -EAGAIN;
553
554 /*
555 * count == 0 is special - no IO is done but we check
556 * for error conditions (see above).
557 */
558 if (count == 0)
559 break;
560
561 while (read + input_event_size() <= count &&
562 evdev_fetch_next_event(client, &event)) {
563
564 if (input_event_to_user(buffer + read, &event))
565 return -EFAULT;
566
567 read += input_event_size();
568 }
569
570 if (read)
571 break;
572
573 if (!(file->f_flags & O_NONBLOCK)) {
574 error = wait_event_interruptible(evdev->wait,
575 client->packet_head != client->tail ||
576 !evdev->exist || client->revoked);
577 if (error)
578 return error;
579 }
580 }
581
582 return read;
583}
584
585/* No kernel lock - fine */
586static unsigned int evdev_poll(struct file *file, poll_table *wait)
587{
588 struct evdev_client *client = file->private_data;
589 struct evdev *evdev = client->evdev;
590 unsigned int mask;
591
592 poll_wait(file, &evdev->wait, wait);
593
594 if (evdev->exist && !client->revoked)
595 mask = POLLOUT | POLLWRNORM;
596 else
597 mask = POLLHUP | POLLERR;
598
599 if (client->packet_head != client->tail)
600 mask |= POLLIN | POLLRDNORM;
601
602 return mask;
603}
604
605#ifdef CONFIG_COMPAT
606
607#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
608#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
609
610#ifdef __BIG_ENDIAN
611static int bits_to_user(unsigned long *bits, unsigned int maxbit,
612 unsigned int maxlen, void __user *p, int compat)
613{
614 int len, i;
615
616 if (compat) {
617 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
618 if (len > maxlen)
619 len = maxlen;
620
621 for (i = 0; i < len / sizeof(compat_long_t); i++)
622 if (copy_to_user((compat_long_t __user *) p + i,
623 (compat_long_t *) bits +
624 i + 1 - ((i % 2) << 1),
625 sizeof(compat_long_t)))
626 return -EFAULT;
627 } else {
628 len = BITS_TO_LONGS(maxbit) * sizeof(long);
629 if (len > maxlen)
630 len = maxlen;
631
632 if (copy_to_user(p, bits, len))
633 return -EFAULT;
634 }
635
636 return len;
637}
638#else
639static int bits_to_user(unsigned long *bits, unsigned int maxbit,
640 unsigned int maxlen, void __user *p, int compat)
641{
642 int len = compat ?
643 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
644 BITS_TO_LONGS(maxbit) * sizeof(long);
645
646 if (len > maxlen)
647 len = maxlen;
648
649 return copy_to_user(p, bits, len) ? -EFAULT : len;
650}
651#endif /* __BIG_ENDIAN */
652
653#else
654
655static int bits_to_user(unsigned long *bits, unsigned int maxbit,
656 unsigned int maxlen, void __user *p, int compat)
657{
658 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
659
660 if (len > maxlen)
661 len = maxlen;
662
663 return copy_to_user(p, bits, len) ? -EFAULT : len;
664}
665
666#endif /* CONFIG_COMPAT */
667
668static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
669{
670 int len;
671
672 if (!str)
673 return -ENOENT;
674
675 len = strlen(str) + 1;
676 if (len > maxlen)
677 len = maxlen;
678
679 return copy_to_user(p, str, len) ? -EFAULT : len;
680}
681
682static int handle_eviocgbit(struct input_dev *dev,
683 unsigned int type, unsigned int size,
684 void __user *p, int compat_mode)
685{
686 unsigned long *bits;
687 int len;
688
689 switch (type) {
690
691 case 0: bits = dev->evbit; len = EV_MAX; break;
692 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
693 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
694 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
695 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
696 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
697 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
698 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
699 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
700 default: return -EINVAL;
701 }
702
703 return bits_to_user(bits, len, size, p, compat_mode);
704}
705
706static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
707{
708 struct input_keymap_entry ke = {
709 .len = sizeof(unsigned int),
710 .flags = 0,
711 };
712 int __user *ip = (int __user *)p;
713 int error;
714
715 /* legacy case */
716 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
717 return -EFAULT;
718
719 error = input_get_keycode(dev, &ke);
720 if (error)
721 return error;
722
723 if (put_user(ke.keycode, ip + 1))
724 return -EFAULT;
725
726 return 0;
727}
728
729static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
730{
731 struct input_keymap_entry ke;
732 int error;
733
734 if (copy_from_user(&ke, p, sizeof(ke)))
735 return -EFAULT;
736
737 error = input_get_keycode(dev, &ke);
738 if (error)
739 return error;
740
741 if (copy_to_user(p, &ke, sizeof(ke)))
742 return -EFAULT;
743
744 return 0;
745}
746
747static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
748{
749 struct input_keymap_entry ke = {
750 .len = sizeof(unsigned int),
751 .flags = 0,
752 };
753 int __user *ip = (int __user *)p;
754
755 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
756 return -EFAULT;
757
758 if (get_user(ke.keycode, ip + 1))
759 return -EFAULT;
760
761 return input_set_keycode(dev, &ke);
762}
763
764static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
765{
766 struct input_keymap_entry ke;
767
768 if (copy_from_user(&ke, p, sizeof(ke)))
769 return -EFAULT;
770
771 if (ke.len > sizeof(ke.scancode))
772 return -EINVAL;
773
774 return input_set_keycode(dev, &ke);
775}
776
777/*
778 * If we transfer state to the user, we should flush all pending events
779 * of the same type from the client's queue. Otherwise, they might end up
780 * with duplicate events, which can screw up client's state tracking.
781 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
782 * event so user-space will notice missing events.
783 *
784 * LOCKING:
785 * We need to take event_lock before buffer_lock to avoid dead-locks. But we
786 * need the even_lock only to guarantee consistent state. We can safely release
787 * it while flushing the queue. This allows input-core to handle filters while
788 * we flush the queue.
789 */
790static int evdev_handle_get_val(struct evdev_client *client,
791 struct input_dev *dev, unsigned int type,
792 unsigned long *bits, unsigned int maxbit,
793 unsigned int maxlen, void __user *p,
794 int compat)
795{
796 int ret;
797 unsigned long *mem;
798 size_t len;
799
800 len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
801 mem = kmalloc(len, GFP_KERNEL);
802 if (!mem)
803 return -ENOMEM;
804
805 spin_lock_irq(&dev->event_lock);
806 spin_lock(&client->buffer_lock);
807
808 memcpy(mem, bits, len);
809
810 spin_unlock(&dev->event_lock);
811
812 __evdev_flush_queue(client, type);
813
814 spin_unlock_irq(&client->buffer_lock);
815
816 ret = bits_to_user(mem, maxbit, maxlen, p, compat);
817 if (ret < 0)
818 evdev_queue_syn_dropped(client);
819
820 kfree(mem);
821
822 return ret;
823}
824
825static int evdev_handle_mt_request(struct input_dev *dev,
826 unsigned int size,
827 int __user *ip)
828{
829 const struct input_mt *mt = dev->mt;
830 unsigned int code;
831 int max_slots;
832 int i;
833
834 if (get_user(code, &ip[0]))
835 return -EFAULT;
836 if (!mt || !input_is_mt_value(code))
837 return -EINVAL;
838
839 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
840 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
841 int value = input_mt_get_value(&mt->slots[i], code);
842 if (put_user(value, &ip[1 + i]))
843 return -EFAULT;
844 }
845
846 return 0;
847}
848
849static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
850 struct file *file)
851{
852 client->revoked = true;
853 evdev_ungrab(evdev, client);
854 input_flush_device(&evdev->handle, file);
855 wake_up_interruptible(&evdev->wait);
856
857 return 0;
858}
859
860static long evdev_do_ioctl(struct file *file, unsigned int cmd,
861 void __user *p, int compat_mode)
862{
863 struct evdev_client *client = file->private_data;
864 struct evdev *evdev = client->evdev;
865 struct input_dev *dev = evdev->handle.dev;
866 struct input_absinfo abs;
867 struct ff_effect effect;
868 int __user *ip = (int __user *)p;
869 unsigned int i, t, u, v;
870 unsigned int size;
871 int error;
872
873 /* First we check for fixed-length commands */
874 switch (cmd) {
875
876 case EVIOCGVERSION:
877 return put_user(EV_VERSION, ip);
878
879 case EVIOCGID:
880 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
881 return -EFAULT;
882 return 0;
883
884 case EVIOCGREP:
885 if (!test_bit(EV_REP, dev->evbit))
886 return -ENOSYS;
887 if (put_user(dev->rep[REP_DELAY], ip))
888 return -EFAULT;
889 if (put_user(dev->rep[REP_PERIOD], ip + 1))
890 return -EFAULT;
891 return 0;
892
893 case EVIOCSREP:
894 if (!test_bit(EV_REP, dev->evbit))
895 return -ENOSYS;
896 if (get_user(u, ip))
897 return -EFAULT;
898 if (get_user(v, ip + 1))
899 return -EFAULT;
900
901 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
902 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
903
904 return 0;
905
906 case EVIOCRMFF:
907 return input_ff_erase(dev, (int)(unsigned long) p, file);
908
909 case EVIOCGEFFECTS:
910 i = test_bit(EV_FF, dev->evbit) ?
911 dev->ff->max_effects : 0;
912 if (put_user(i, ip))
913 return -EFAULT;
914 return 0;
915
916 case EVIOCGRAB:
917 if (p)
918 return evdev_grab(evdev, client);
919 else
920 return evdev_ungrab(evdev, client);
921
922 case EVIOCREVOKE:
923 if (p)
924 return -EINVAL;
925 else
926 return evdev_revoke(evdev, client, file);
927
928 case EVIOCSCLOCKID:
929 if (copy_from_user(&i, p, sizeof(unsigned int)))
930 return -EFAULT;
931
932 return evdev_set_clk_type(client, i);
933
934 case EVIOCGKEYCODE:
935 return evdev_handle_get_keycode(dev, p);
936
937 case EVIOCSKEYCODE:
938 return evdev_handle_set_keycode(dev, p);
939
940 case EVIOCGKEYCODE_V2:
941 return evdev_handle_get_keycode_v2(dev, p);
942
943 case EVIOCSKEYCODE_V2:
944 return evdev_handle_set_keycode_v2(dev, p);
945 }
946
947 size = _IOC_SIZE(cmd);
948
949 /* Now check variable-length commands */
950#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
951 switch (EVIOC_MASK_SIZE(cmd)) {
952
953 case EVIOCGPROP(0):
954 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
955 size, p, compat_mode);
956
957 case EVIOCGMTSLOTS(0):
958 return evdev_handle_mt_request(dev, size, ip);
959
960 case EVIOCGKEY(0):
961 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
962 KEY_MAX, size, p, compat_mode);
963
964 case EVIOCGLED(0):
965 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
966 LED_MAX, size, p, compat_mode);
967
968 case EVIOCGSND(0):
969 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
970 SND_MAX, size, p, compat_mode);
971
972 case EVIOCGSW(0):
973 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
974 SW_MAX, size, p, compat_mode);
975
976 case EVIOCGNAME(0):
977 return str_to_user(dev->name, size, p);
978
979 case EVIOCGPHYS(0):
980 return str_to_user(dev->phys, size, p);
981
982 case EVIOCGUNIQ(0):
983 return str_to_user(dev->uniq, size, p);
984
985 case EVIOC_MASK_SIZE(EVIOCSFF):
986 if (input_ff_effect_from_user(p, size, &effect))
987 return -EFAULT;
988
989 error = input_ff_upload(dev, &effect, file);
990 if (error)
991 return error;
992
993 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
994 return -EFAULT;
995
996 return 0;
997 }
998
999 /* Multi-number variable-length handlers */
1000 if (_IOC_TYPE(cmd) != 'E')
1001 return -EINVAL;
1002
1003 if (_IOC_DIR(cmd) == _IOC_READ) {
1004
1005 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1006 return handle_eviocgbit(dev,
1007 _IOC_NR(cmd) & EV_MAX, size,
1008 p, compat_mode);
1009
1010 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1011
1012 if (!dev->absinfo)
1013 return -EINVAL;
1014
1015 t = _IOC_NR(cmd) & ABS_MAX;
1016 abs = dev->absinfo[t];
1017
1018 if (copy_to_user(p, &abs, min_t(size_t,
1019 size, sizeof(struct input_absinfo))))
1020 return -EFAULT;
1021
1022 return 0;
1023 }
1024 }
1025
1026 if (_IOC_DIR(cmd) == _IOC_WRITE) {
1027
1028 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1029
1030 if (!dev->absinfo)
1031 return -EINVAL;
1032
1033 t = _IOC_NR(cmd) & ABS_MAX;
1034
1035 if (copy_from_user(&abs, p, min_t(size_t,
1036 size, sizeof(struct input_absinfo))))
1037 return -EFAULT;
1038
1039 if (size < sizeof(struct input_absinfo))
1040 abs.resolution = 0;
1041
1042 /* We can't change number of reserved MT slots */
1043 if (t == ABS_MT_SLOT)
1044 return -EINVAL;
1045
1046 /*
1047 * Take event lock to ensure that we are not
1048 * changing device parameters in the middle
1049 * of event.
1050 */
1051 spin_lock_irq(&dev->event_lock);
1052 dev->absinfo[t] = abs;
1053 spin_unlock_irq(&dev->event_lock);
1054
1055 return 0;
1056 }
1057 }
1058
1059 return -EINVAL;
1060}
1061
1062static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1063 void __user *p, int compat_mode)
1064{
1065 struct evdev_client *client = file->private_data;
1066 struct evdev *evdev = client->evdev;
1067 int retval;
1068
1069 retval = mutex_lock_interruptible(&evdev->mutex);
1070 if (retval)
1071 return retval;
1072
1073 if (!evdev->exist || client->revoked) {
1074 retval = -ENODEV;
1075 goto out;
1076 }
1077
1078 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1079
1080 out:
1081 mutex_unlock(&evdev->mutex);
1082 return retval;
1083}
1084
1085static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1086{
1087 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1088}
1089
1090#ifdef CONFIG_COMPAT
1091static long evdev_ioctl_compat(struct file *file,
1092 unsigned int cmd, unsigned long arg)
1093{
1094 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1095}
1096#endif
1097
1098static const struct file_operations evdev_fops = {
1099 .owner = THIS_MODULE,
1100 .read = evdev_read,
1101 .write = evdev_write,
1102 .poll = evdev_poll,
1103 .open = evdev_open,
1104 .release = evdev_release,
1105 .unlocked_ioctl = evdev_ioctl,
1106#ifdef CONFIG_COMPAT
1107 .compat_ioctl = evdev_ioctl_compat,
1108#endif
1109 .fasync = evdev_fasync,
1110 .flush = evdev_flush,
1111 .llseek = no_llseek,
1112};
1113
1114/*
1115 * Mark device non-existent. This disables writes, ioctls and
1116 * prevents new users from opening the device. Already posted
1117 * blocking reads will stay, however new ones will fail.
1118 */
1119static void evdev_mark_dead(struct evdev *evdev)
1120{
1121 mutex_lock(&evdev->mutex);
1122 evdev->exist = false;
1123 mutex_unlock(&evdev->mutex);
1124}
1125
1126static void evdev_cleanup(struct evdev *evdev)
1127{
1128 struct input_handle *handle = &evdev->handle;
1129
1130 evdev_mark_dead(evdev);
1131 evdev_hangup(evdev);
1132
1133 cdev_del(&evdev->cdev);
1134
1135 /* evdev is marked dead so no one else accesses evdev->open */
1136 if (evdev->open) {
1137 input_flush_device(handle, NULL);
1138 input_close_device(handle);
1139 }
1140}
1141
1142/*
1143 * Create new evdev device. Note that input core serializes calls
1144 * to connect and disconnect.
1145 */
1146static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1147 const struct input_device_id *id)
1148{
1149 struct evdev *evdev;
1150 int minor;
1151 int dev_no;
1152 int error;
1153
1154 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1155 if (minor < 0) {
1156 error = minor;
1157 pr_err("failed to reserve new minor: %d\n", error);
1158 return error;
1159 }
1160
1161 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1162 if (!evdev) {
1163 error = -ENOMEM;
1164 goto err_free_minor;
1165 }
1166
1167 INIT_LIST_HEAD(&evdev->client_list);
1168 spin_lock_init(&evdev->client_lock);
1169 mutex_init(&evdev->mutex);
1170 init_waitqueue_head(&evdev->wait);
1171 evdev->exist = true;
1172
1173 dev_no = minor;
1174 /* Normalize device number if it falls into legacy range */
1175 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1176 dev_no -= EVDEV_MINOR_BASE;
1177 dev_set_name(&evdev->dev, "event%d", dev_no);
1178
1179 evdev->handle.dev = input_get_device(dev);
1180 evdev->handle.name = dev_name(&evdev->dev);
1181 evdev->handle.handler = handler;
1182 evdev->handle.private = evdev;
1183
1184 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1185 evdev->dev.class = &input_class;
1186 evdev->dev.parent = &dev->dev;
1187 evdev->dev.release = evdev_free;
1188 device_initialize(&evdev->dev);
1189
1190 error = input_register_handle(&evdev->handle);
1191 if (error)
1192 goto err_free_evdev;
1193
1194 cdev_init(&evdev->cdev, &evdev_fops);
1195 evdev->cdev.kobj.parent = &evdev->dev.kobj;
1196 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1197 if (error)
1198 goto err_unregister_handle;
1199
1200 error = device_add(&evdev->dev);
1201 if (error)
1202 goto err_cleanup_evdev;
1203
1204 return 0;
1205
1206 err_cleanup_evdev:
1207 evdev_cleanup(evdev);
1208 err_unregister_handle:
1209 input_unregister_handle(&evdev->handle);
1210 err_free_evdev:
1211 put_device(&evdev->dev);
1212 err_free_minor:
1213 input_free_minor(minor);
1214 return error;
1215}
1216
1217static void evdev_disconnect(struct input_handle *handle)
1218{
1219 struct evdev *evdev = handle->private;
1220
1221 device_del(&evdev->dev);
1222 evdev_cleanup(evdev);
1223 input_free_minor(MINOR(evdev->dev.devt));
1224 input_unregister_handle(handle);
1225 put_device(&evdev->dev);
1226}
1227
1228static const struct input_device_id evdev_ids[] = {
1229 { .driver_info = 1 }, /* Matches all devices */
1230 { }, /* Terminating zero entry */
1231};
1232
1233MODULE_DEVICE_TABLE(input, evdev_ids);
1234
1235static struct input_handler evdev_handler = {
1236 .event = evdev_event,
1237 .events = evdev_events,
1238 .connect = evdev_connect,
1239 .disconnect = evdev_disconnect,
1240 .legacy_minors = true,
1241 .minor = EVDEV_MINOR_BASE,
1242 .name = "evdev",
1243 .id_table = evdev_ids,
1244};
1245
1246static int __init evdev_init(void)
1247{
1248 return input_register_handler(&evdev_handler);
1249}
1250
1251static void __exit evdev_exit(void)
1252{
1253 input_unregister_handler(&evdev_handler);
1254}
1255
1256module_init(evdev_init);
1257module_exit(evdev_exit);
1258
1259MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
1260MODULE_DESCRIPTION("Input driver event char devices");
1261MODULE_LICENSE("GPL");