projects/linux·blob v4.13 · refs

1478 lines · 33.1 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 unsigned int clk_type;
60 bool revoked;
61 unsigned long *evmasks[EV_CNT];
62 unsigned int bufsize;
63 struct input_event buffer[];
64};
65
66static size_t evdev_get_mask_cnt(unsigned int type)
67{
68 static const size_t counts[EV_CNT] = {
69 /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
70 [EV_SYN] = EV_CNT,
71 [EV_KEY] = KEY_CNT,
72 [EV_REL] = REL_CNT,
73 [EV_ABS] = ABS_CNT,
74 [EV_MSC] = MSC_CNT,
75 [EV_SW] = SW_CNT,
76 [EV_LED] = LED_CNT,
77 [EV_SND] = SND_CNT,
78 [EV_FF] = FF_CNT,
79 };
80
81 return (type < EV_CNT) ? counts[type] : 0;
82}
83
84/* requires the buffer lock to be held */
85static bool __evdev_is_filtered(struct evdev_client *client,
86 unsigned int type,
87 unsigned int code)
88{
89 unsigned long *mask;
90 size_t cnt;
91
92 /* EV_SYN and unknown codes are never filtered */
93 if (type == EV_SYN || type >= EV_CNT)
94 return false;
95
96 /* first test whether the type is filtered */
97 mask = client->evmasks[0];
98 if (mask && !test_bit(type, mask))
99 return true;
100
101 /* unknown values are never filtered */
102 cnt = evdev_get_mask_cnt(type);
103 if (!cnt || code >= cnt)
104 return false;
105
106 mask = client->evmasks[type];
107 return mask && !test_bit(code, mask);
108}
109
110/* flush queued events of type @type, caller must hold client->buffer_lock */
111static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
112{
113 unsigned int i, head, num;
114 unsigned int mask = client->bufsize - 1;
115 bool is_report;
116 struct input_event *ev;
117
118 BUG_ON(type == EV_SYN);
119
120 head = client->tail;
121 client->packet_head = client->tail;
122
123 /* init to 1 so a leading SYN_REPORT will not be dropped */
124 num = 1;
125
126 for (i = client->tail; i != client->head; i = (i + 1) & mask) {
127 ev = &client->buffer[i];
128 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
129
130 if (ev->type == type) {
131 /* drop matched entry */
132 continue;
133 } else if (is_report && !num) {
134 /* drop empty SYN_REPORT groups */
135 continue;
136 } else if (head != i) {
137 /* move entry to fill the gap */
138 client->buffer[head].time = ev->time;
139 client->buffer[head].type = ev->type;
140 client->buffer[head].code = ev->code;
141 client->buffer[head].value = ev->value;
142 }
143
144 num++;
145 head = (head + 1) & mask;
146
147 if (is_report) {
148 num = 0;
149 client->packet_head = head;
150 }
151 }
152
153 client->head = head;
154}
155
156static void __evdev_queue_syn_dropped(struct evdev_client *client)
157{
158 struct input_event ev;
159 ktime_t time;
160
161 time = client->clk_type == EV_CLK_REAL ?
162 ktime_get_real() :
163 client->clk_type == EV_CLK_MONO ?
164 ktime_get() :
165 ktime_get_boottime();
166
167 ev.time = ktime_to_timeval(time);
168 ev.type = EV_SYN;
169 ev.code = SYN_DROPPED;
170 ev.value = 0;
171
172 client->buffer[client->head++] = ev;
173 client->head &= client->bufsize - 1;
174
175 if (unlikely(client->head == client->tail)) {
176 /* drop queue but keep our SYN_DROPPED event */
177 client->tail = (client->head - 1) & (client->bufsize - 1);
178 client->packet_head = client->tail;
179 }
180}
181
182static void evdev_queue_syn_dropped(struct evdev_client *client)
183{
184 unsigned long flags;
185
186 spin_lock_irqsave(&client->buffer_lock, flags);
187 __evdev_queue_syn_dropped(client);
188 spin_unlock_irqrestore(&client->buffer_lock, flags);
189}
190
191static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
192{
193 unsigned long flags;
194 unsigned int clk_type;
195
196 switch (clkid) {
197
198 case CLOCK_REALTIME:
199 clk_type = EV_CLK_REAL;
200 break;
201 case CLOCK_MONOTONIC:
202 clk_type = EV_CLK_MONO;
203 break;
204 case CLOCK_BOOTTIME:
205 clk_type = EV_CLK_BOOT;
206 break;
207 default:
208 return -EINVAL;
209 }
210
211 if (client->clk_type != clk_type) {
212 client->clk_type = clk_type;
213
214 /*
215 * Flush pending events and queue SYN_DROPPED event,
216 * but only if the queue is not empty.
217 */
218 spin_lock_irqsave(&client->buffer_lock, flags);
219
220 if (client->head != client->tail) {
221 client->packet_head = client->head = client->tail;
222 __evdev_queue_syn_dropped(client);
223 }
224
225 spin_unlock_irqrestore(&client->buffer_lock, flags);
226 }
227
228 return 0;
229}
230
231static void __pass_event(struct evdev_client *client,
232 const struct input_event *event)
233{
234 client->buffer[client->head++] = *event;
235 client->head &= client->bufsize - 1;
236
237 if (unlikely(client->head == client->tail)) {
238 /*
239 * This effectively "drops" all unconsumed events, leaving
240 * EV_SYN/SYN_DROPPED plus the newest event in the queue.
241 */
242 client->tail = (client->head - 2) & (client->bufsize - 1);
243
244 client->buffer[client->tail].time = event->time;
245 client->buffer[client->tail].type = EV_SYN;
246 client->buffer[client->tail].code = SYN_DROPPED;
247 client->buffer[client->tail].value = 0;
248
249 client->packet_head = client->tail;
250 }
251
252 if (event->type == EV_SYN && event->code == SYN_REPORT) {
253 client->packet_head = client->head;
254 kill_fasync(&client->fasync, SIGIO, POLL_IN);
255 }
256}
257
258static void evdev_pass_values(struct evdev_client *client,
259 const struct input_value *vals, unsigned int count,
260 ktime_t *ev_time)
261{
262 struct evdev *evdev = client->evdev;
263 const struct input_value *v;
264 struct input_event event;
265 bool wakeup = false;
266
267 if (client->revoked)
268 return;
269
270 event.time = ktime_to_timeval(ev_time[client->clk_type]);
271
272 /* Interrupts are disabled, just acquire the lock. */
273 spin_lock(&client->buffer_lock);
274
275 for (v = vals; v != vals + count; v++) {
276 if (__evdev_is_filtered(client, v->type, v->code))
277 continue;
278
279 if (v->type == EV_SYN && v->code == SYN_REPORT) {
280 /* drop empty SYN_REPORT */
281 if (client->packet_head == client->head)
282 continue;
283
284 wakeup = true;
285 }
286
287 event.type = v->type;
288 event.code = v->code;
289 event.value = v->value;
290 __pass_event(client, &event);
291 }
292
293 spin_unlock(&client->buffer_lock);
294
295 if (wakeup)
296 wake_up_interruptible(&evdev->wait);
297}
298
299/*
300 * Pass incoming events to all connected clients.
301 */
302static void evdev_events(struct input_handle *handle,
303 const struct input_value *vals, unsigned int count)
304{
305 struct evdev *evdev = handle->private;
306 struct evdev_client *client;
307 ktime_t ev_time[EV_CLK_MAX];
308
309 ev_time[EV_CLK_MONO] = ktime_get();
310 ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
311 ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
312 TK_OFFS_BOOT);
313
314 rcu_read_lock();
315
316 client = rcu_dereference(evdev->grab);
317
318 if (client)
319 evdev_pass_values(client, vals, count, ev_time);
320 else
321 list_for_each_entry_rcu(client, &evdev->client_list, node)
322 evdev_pass_values(client, vals, count, ev_time);
323
324 rcu_read_unlock();
325}
326
327/*
328 * Pass incoming event to all connected clients.
329 */
330static void evdev_event(struct input_handle *handle,
331 unsigned int type, unsigned int code, int value)
332{
333 struct input_value vals[] = { { type, code, value } };
334
335 evdev_events(handle, vals, 1);
336}
337
338static int evdev_fasync(int fd, struct file *file, int on)
339{
340 struct evdev_client *client = file->private_data;
341
342 return fasync_helper(fd, file, on, &client->fasync);
343}
344
345static int evdev_flush(struct file *file, fl_owner_t id)
346{
347 struct evdev_client *client = file->private_data;
348 struct evdev *evdev = client->evdev;
349
350 mutex_lock(&evdev->mutex);
351
352 if (evdev->exist && !client->revoked)
353 input_flush_device(&evdev->handle, file);
354
355 mutex_unlock(&evdev->mutex);
356 return 0;
357}
358
359static void evdev_free(struct device *dev)
360{
361 struct evdev *evdev = container_of(dev, struct evdev, dev);
362
363 input_put_device(evdev->handle.dev);
364 kfree(evdev);
365}
366
367/*
368 * Grabs an event device (along with underlying input device).
369 * This function is called with evdev->mutex taken.
370 */
371static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
372{
373 int error;
374
375 if (evdev->grab)
376 return -EBUSY;
377
378 error = input_grab_device(&evdev->handle);
379 if (error)
380 return error;
381
382 rcu_assign_pointer(evdev->grab, client);
383
384 return 0;
385}
386
387static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
388{
389 struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
390 lockdep_is_held(&evdev->mutex));
391
392 if (grab != client)
393 return -EINVAL;
394
395 rcu_assign_pointer(evdev->grab, NULL);
396 synchronize_rcu();
397 input_release_device(&evdev->handle);
398
399 return 0;
400}
401
402static void evdev_attach_client(struct evdev *evdev,
403 struct evdev_client *client)
404{
405 spin_lock(&evdev->client_lock);
406 list_add_tail_rcu(&client->node, &evdev->client_list);
407 spin_unlock(&evdev->client_lock);
408}
409
410static void evdev_detach_client(struct evdev *evdev,
411 struct evdev_client *client)
412{
413 spin_lock(&evdev->client_lock);
414 list_del_rcu(&client->node);
415 spin_unlock(&evdev->client_lock);
416 synchronize_rcu();
417}
418
419static int evdev_open_device(struct evdev *evdev)
420{
421 int retval;
422
423 retval = mutex_lock_interruptible(&evdev->mutex);
424 if (retval)
425 return retval;
426
427 if (!evdev->exist)
428 retval = -ENODEV;
429 else if (!evdev->open++) {
430 retval = input_open_device(&evdev->handle);
431 if (retval)
432 evdev->open--;
433 }
434
435 mutex_unlock(&evdev->mutex);
436 return retval;
437}
438
439static void evdev_close_device(struct evdev *evdev)
440{
441 mutex_lock(&evdev->mutex);
442
443 if (evdev->exist && !--evdev->open)
444 input_close_device(&evdev->handle);
445
446 mutex_unlock(&evdev->mutex);
447}
448
449/*
450 * Wake up users waiting for IO so they can disconnect from
451 * dead device.
452 */
453static void evdev_hangup(struct evdev *evdev)
454{
455 struct evdev_client *client;
456
457 spin_lock(&evdev->client_lock);
458 list_for_each_entry(client, &evdev->client_list, node)
459 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
460 spin_unlock(&evdev->client_lock);
461
462 wake_up_interruptible(&evdev->wait);
463}
464
465static int evdev_release(struct inode *inode, struct file *file)
466{
467 struct evdev_client *client = file->private_data;
468 struct evdev *evdev = client->evdev;
469 unsigned int i;
470
471 mutex_lock(&evdev->mutex);
472 evdev_ungrab(evdev, client);
473 mutex_unlock(&evdev->mutex);
474
475 evdev_detach_client(evdev, client);
476
477 for (i = 0; i < EV_CNT; ++i)
478 kfree(client->evmasks[i]);
479
480 kvfree(client);
481
482 evdev_close_device(evdev);
483
484 return 0;
485}
486
487static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
488{
489 unsigned int n_events =
490 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
491 EVDEV_MIN_BUFFER_SIZE);
492
493 return roundup_pow_of_two(n_events);
494}
495
496static int evdev_open(struct inode *inode, struct file *file)
497{
498 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
499 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
500 unsigned int size = sizeof(struct evdev_client) +
501 bufsize * sizeof(struct input_event);
502 struct evdev_client *client;
503 int error;
504
505 client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
506 if (!client)
507 client = vzalloc(size);
508 if (!client)
509 return -ENOMEM;
510
511 client->bufsize = bufsize;
512 spin_lock_init(&client->buffer_lock);
513 client->evdev = evdev;
514 evdev_attach_client(evdev, client);
515
516 error = evdev_open_device(evdev);
517 if (error)
518 goto err_free_client;
519
520 file->private_data = client;
521 nonseekable_open(inode, file);
522
523 return 0;
524
525 err_free_client:
526 evdev_detach_client(evdev, client);
527 kvfree(client);
528 return error;
529}
530
531static ssize_t evdev_write(struct file *file, const char __user *buffer,
532 size_t count, loff_t *ppos)
533{
534 struct evdev_client *client = file->private_data;
535 struct evdev *evdev = client->evdev;
536 struct input_event event;
537 int retval = 0;
538
539 if (count != 0 && count < input_event_size())
540 return -EINVAL;
541
542 retval = mutex_lock_interruptible(&evdev->mutex);
543 if (retval)
544 return retval;
545
546 if (!evdev->exist || client->revoked) {
547 retval = -ENODEV;
548 goto out;
549 }
550
551 while (retval + input_event_size() <= count) {
552
553 if (input_event_from_user(buffer + retval, &event)) {
554 retval = -EFAULT;
555 goto out;
556 }
557 retval += input_event_size();
558
559 input_inject_event(&evdev->handle,
560 event.type, event.code, event.value);
561 }
562
563 out:
564 mutex_unlock(&evdev->mutex);
565 return retval;
566}
567
568static int evdev_fetch_next_event(struct evdev_client *client,
569 struct input_event *event)
570{
571 int have_event;
572
573 spin_lock_irq(&client->buffer_lock);
574
575 have_event = client->packet_head != client->tail;
576 if (have_event) {
577 *event = client->buffer[client->tail++];
578 client->tail &= client->bufsize - 1;
579 }
580
581 spin_unlock_irq(&client->buffer_lock);
582
583 return have_event;
584}
585
586static ssize_t evdev_read(struct file *file, char __user *buffer,
587 size_t count, loff_t *ppos)
588{
589 struct evdev_client *client = file->private_data;
590 struct evdev *evdev = client->evdev;
591 struct input_event event;
592 size_t read = 0;
593 int error;
594
595 if (count != 0 && count < input_event_size())
596 return -EINVAL;
597
598 for (;;) {
599 if (!evdev->exist || client->revoked)
600 return -ENODEV;
601
602 if (client->packet_head == client->tail &&
603 (file->f_flags & O_NONBLOCK))
604 return -EAGAIN;
605
606 /*
607 * count == 0 is special - no IO is done but we check
608 * for error conditions (see above).
609 */
610 if (count == 0)
611 break;
612
613 while (read + input_event_size() <= count &&
614 evdev_fetch_next_event(client, &event)) {
615
616 if (input_event_to_user(buffer + read, &event))
617 return -EFAULT;
618
619 read += input_event_size();
620 }
621
622 if (read)
623 break;
624
625 if (!(file->f_flags & O_NONBLOCK)) {
626 error = wait_event_interruptible(evdev->wait,
627 client->packet_head != client->tail ||
628 !evdev->exist || client->revoked);
629 if (error)
630 return error;
631 }
632 }
633
634 return read;
635}
636
637/* No kernel lock - fine */
638static unsigned int evdev_poll(struct file *file, poll_table *wait)
639{
640 struct evdev_client *client = file->private_data;
641 struct evdev *evdev = client->evdev;
642 unsigned int mask;
643
644 poll_wait(file, &evdev->wait, wait);
645
646 if (evdev->exist && !client->revoked)
647 mask = POLLOUT | POLLWRNORM;
648 else
649 mask = POLLHUP | POLLERR;
650
651 if (client->packet_head != client->tail)
652 mask |= POLLIN | POLLRDNORM;
653
654 return mask;
655}
656
657#ifdef CONFIG_COMPAT
658
659#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
660#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
661
662#ifdef __BIG_ENDIAN
663static int bits_to_user(unsigned long *bits, unsigned int maxbit,
664 unsigned int maxlen, void __user *p, int compat)
665{
666 int len, i;
667
668 if (compat) {
669 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
670 if (len > maxlen)
671 len = maxlen;
672
673 for (i = 0; i < len / sizeof(compat_long_t); i++)
674 if (copy_to_user((compat_long_t __user *) p + i,
675 (compat_long_t *) bits +
676 i + 1 - ((i % 2) << 1),
677 sizeof(compat_long_t)))
678 return -EFAULT;
679 } else {
680 len = BITS_TO_LONGS(maxbit) * sizeof(long);
681 if (len > maxlen)
682 len = maxlen;
683
684 if (copy_to_user(p, bits, len))
685 return -EFAULT;
686 }
687
688 return len;
689}
690
691static int bits_from_user(unsigned long *bits, unsigned int maxbit,
692 unsigned int maxlen, const void __user *p, int compat)
693{
694 int len, i;
695
696 if (compat) {
697 if (maxlen % sizeof(compat_long_t))
698 return -EINVAL;
699
700 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
701 if (len > maxlen)
702 len = maxlen;
703
704 for (i = 0; i < len / sizeof(compat_long_t); i++)
705 if (copy_from_user((compat_long_t *) bits +
706 i + 1 - ((i % 2) << 1),
707 (compat_long_t __user *) p + i,
708 sizeof(compat_long_t)))
709 return -EFAULT;
710 if (i % 2)
711 *((compat_long_t *) bits + i - 1) = 0;
712
713 } else {
714 if (maxlen % sizeof(long))
715 return -EINVAL;
716
717 len = BITS_TO_LONGS(maxbit) * sizeof(long);
718 if (len > maxlen)
719 len = maxlen;
720
721 if (copy_from_user(bits, p, len))
722 return -EFAULT;
723 }
724
725 return len;
726}
727
728#else
729
730static int bits_to_user(unsigned long *bits, unsigned int maxbit,
731 unsigned int maxlen, void __user *p, int compat)
732{
733 int len = compat ?
734 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
735 BITS_TO_LONGS(maxbit) * sizeof(long);
736
737 if (len > maxlen)
738 len = maxlen;
739
740 return copy_to_user(p, bits, len) ? -EFAULT : len;
741}
742
743static int bits_from_user(unsigned long *bits, unsigned int maxbit,
744 unsigned int maxlen, const void __user *p, int compat)
745{
746 size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
747 int len;
748
749 if (maxlen % chunk_size)
750 return -EINVAL;
751
752 len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
753 len *= chunk_size;
754 if (len > maxlen)
755 len = maxlen;
756
757 return copy_from_user(bits, p, len) ? -EFAULT : len;
758}
759
760#endif /* __BIG_ENDIAN */
761
762#else
763
764static int bits_to_user(unsigned long *bits, unsigned int maxbit,
765 unsigned int maxlen, void __user *p, int compat)
766{
767 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
768
769 if (len > maxlen)
770 len = maxlen;
771
772 return copy_to_user(p, bits, len) ? -EFAULT : len;
773}
774
775static int bits_from_user(unsigned long *bits, unsigned int maxbit,
776 unsigned int maxlen, const void __user *p, int compat)
777{
778 int len;
779
780 if (maxlen % sizeof(long))
781 return -EINVAL;
782
783 len = BITS_TO_LONGS(maxbit) * sizeof(long);
784 if (len > maxlen)
785 len = maxlen;
786
787 return copy_from_user(bits, p, len) ? -EFAULT : len;
788}
789
790#endif /* CONFIG_COMPAT */
791
792static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
793{
794 int len;
795
796 if (!str)
797 return -ENOENT;
798
799 len = strlen(str) + 1;
800 if (len > maxlen)
801 len = maxlen;
802
803 return copy_to_user(p, str, len) ? -EFAULT : len;
804}
805
806static int handle_eviocgbit(struct input_dev *dev,
807 unsigned int type, unsigned int size,
808 void __user *p, int compat_mode)
809{
810 unsigned long *bits;
811 int len;
812
813 switch (type) {
814
815 case 0: bits = dev->evbit; len = EV_MAX; break;
816 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
817 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
818 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
819 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
820 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
821 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
822 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
823 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
824 default: return -EINVAL;
825 }
826
827 return bits_to_user(bits, len, size, p, compat_mode);
828}
829
830static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
831{
832 struct input_keymap_entry ke = {
833 .len = sizeof(unsigned int),
834 .flags = 0,
835 };
836 int __user *ip = (int __user *)p;
837 int error;
838
839 /* legacy case */
840 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
841 return -EFAULT;
842
843 error = input_get_keycode(dev, &ke);
844 if (error)
845 return error;
846
847 if (put_user(ke.keycode, ip + 1))
848 return -EFAULT;
849
850 return 0;
851}
852
853static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
854{
855 struct input_keymap_entry ke;
856 int error;
857
858 if (copy_from_user(&ke, p, sizeof(ke)))
859 return -EFAULT;
860
861 error = input_get_keycode(dev, &ke);
862 if (error)
863 return error;
864
865 if (copy_to_user(p, &ke, sizeof(ke)))
866 return -EFAULT;
867
868 return 0;
869}
870
871static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
872{
873 struct input_keymap_entry ke = {
874 .len = sizeof(unsigned int),
875 .flags = 0,
876 };
877 int __user *ip = (int __user *)p;
878
879 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
880 return -EFAULT;
881
882 if (get_user(ke.keycode, ip + 1))
883 return -EFAULT;
884
885 return input_set_keycode(dev, &ke);
886}
887
888static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
889{
890 struct input_keymap_entry ke;
891
892 if (copy_from_user(&ke, p, sizeof(ke)))
893 return -EFAULT;
894
895 if (ke.len > sizeof(ke.scancode))
896 return -EINVAL;
897
898 return input_set_keycode(dev, &ke);
899}
900
901/*
902 * If we transfer state to the user, we should flush all pending events
903 * of the same type from the client's queue. Otherwise, they might end up
904 * with duplicate events, which can screw up client's state tracking.
905 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
906 * event so user-space will notice missing events.
907 *
908 * LOCKING:
909 * We need to take event_lock before buffer_lock to avoid dead-locks. But we
910 * need the even_lock only to guarantee consistent state. We can safely release
911 * it while flushing the queue. This allows input-core to handle filters while
912 * we flush the queue.
913 */
914static int evdev_handle_get_val(struct evdev_client *client,
915 struct input_dev *dev, unsigned int type,
916 unsigned long *bits, unsigned int maxbit,
917 unsigned int maxlen, void __user *p,
918 int compat)
919{
920 int ret;
921 unsigned long *mem;
922 size_t len;
923
924 len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
925 mem = kmalloc(len, GFP_KERNEL);
926 if (!mem)
927 return -ENOMEM;
928
929 spin_lock_irq(&dev->event_lock);
930 spin_lock(&client->buffer_lock);
931
932 memcpy(mem, bits, len);
933
934 spin_unlock(&dev->event_lock);
935
936 __evdev_flush_queue(client, type);
937
938 spin_unlock_irq(&client->buffer_lock);
939
940 ret = bits_to_user(mem, maxbit, maxlen, p, compat);
941 if (ret < 0)
942 evdev_queue_syn_dropped(client);
943
944 kfree(mem);
945
946 return ret;
947}
948
949static int evdev_handle_mt_request(struct input_dev *dev,
950 unsigned int size,
951 int __user *ip)
952{
953 const struct input_mt *mt = dev->mt;
954 unsigned int code;
955 int max_slots;
956 int i;
957
958 if (get_user(code, &ip[0]))
959 return -EFAULT;
960 if (!mt || !input_is_mt_value(code))
961 return -EINVAL;
962
963 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
964 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
965 int value = input_mt_get_value(&mt->slots[i], code);
966 if (put_user(value, &ip[1 + i]))
967 return -EFAULT;
968 }
969
970 return 0;
971}
972
973static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
974 struct file *file)
975{
976 client->revoked = true;
977 evdev_ungrab(evdev, client);
978 input_flush_device(&evdev->handle, file);
979 wake_up_interruptible(&evdev->wait);
980
981 return 0;
982}
983
984/* must be called with evdev-mutex held */
985static int evdev_set_mask(struct evdev_client *client,
986 unsigned int type,
987 const void __user *codes,
988 u32 codes_size,
989 int compat)
990{
991 unsigned long flags, *mask, *oldmask;
992 size_t cnt;
993 int error;
994
995 /* we allow unknown types and 'codes_size > size' for forward-compat */
996 cnt = evdev_get_mask_cnt(type);
997 if (!cnt)
998 return 0;
999
1000 mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL);
1001 if (!mask)
1002 return -ENOMEM;
1003
1004 error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1005 if (error < 0) {
1006 kfree(mask);
1007 return error;
1008 }
1009
1010 spin_lock_irqsave(&client->buffer_lock, flags);
1011 oldmask = client->evmasks[type];
1012 client->evmasks[type] = mask;
1013 spin_unlock_irqrestore(&client->buffer_lock, flags);
1014
1015 kfree(oldmask);
1016
1017 return 0;
1018}
1019
1020/* must be called with evdev-mutex held */
1021static int evdev_get_mask(struct evdev_client *client,
1022 unsigned int type,
1023 void __user *codes,
1024 u32 codes_size,
1025 int compat)
1026{
1027 unsigned long *mask;
1028 size_t cnt, size, xfer_size;
1029 int i;
1030 int error;
1031
1032 /* we allow unknown types and 'codes_size > size' for forward-compat */
1033 cnt = evdev_get_mask_cnt(type);
1034 size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1035 xfer_size = min_t(size_t, codes_size, size);
1036
1037 if (cnt > 0) {
1038 mask = client->evmasks[type];
1039 if (mask) {
1040 error = bits_to_user(mask, cnt - 1,
1041 xfer_size, codes, compat);
1042 if (error < 0)
1043 return error;
1044 } else {
1045 /* fake mask with all bits set */
1046 for (i = 0; i < xfer_size; i++)
1047 if (put_user(0xffU, (u8 __user *)codes + i))
1048 return -EFAULT;
1049 }
1050 }
1051
1052 if (xfer_size < codes_size)
1053 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1054 return -EFAULT;
1055
1056 return 0;
1057}
1058
1059static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1060 void __user *p, int compat_mode)
1061{
1062 struct evdev_client *client = file->private_data;
1063 struct evdev *evdev = client->evdev;
1064 struct input_dev *dev = evdev->handle.dev;
1065 struct input_absinfo abs;
1066 struct input_mask mask;
1067 struct ff_effect effect;
1068 int __user *ip = (int __user *)p;
1069 unsigned int i, t, u, v;
1070 unsigned int size;
1071 int error;
1072
1073 /* First we check for fixed-length commands */
1074 switch (cmd) {
1075
1076 case EVIOCGVERSION:
1077 return put_user(EV_VERSION, ip);
1078
1079 case EVIOCGID:
1080 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1081 return -EFAULT;
1082 return 0;
1083
1084 case EVIOCGREP:
1085 if (!test_bit(EV_REP, dev->evbit))
1086 return -ENOSYS;
1087 if (put_user(dev->rep[REP_DELAY], ip))
1088 return -EFAULT;
1089 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1090 return -EFAULT;
1091 return 0;
1092
1093 case EVIOCSREP:
1094 if (!test_bit(EV_REP, dev->evbit))
1095 return -ENOSYS;
1096 if (get_user(u, ip))
1097 return -EFAULT;
1098 if (get_user(v, ip + 1))
1099 return -EFAULT;
1100
1101 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1102 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1103
1104 return 0;
1105
1106 case EVIOCRMFF:
1107 return input_ff_erase(dev, (int)(unsigned long) p, file);
1108
1109 case EVIOCGEFFECTS:
1110 i = test_bit(EV_FF, dev->evbit) ?
1111 dev->ff->max_effects : 0;
1112 if (put_user(i, ip))
1113 return -EFAULT;
1114 return 0;
1115
1116 case EVIOCGRAB:
1117 if (p)
1118 return evdev_grab(evdev, client);
1119 else
1120 return evdev_ungrab(evdev, client);
1121
1122 case EVIOCREVOKE:
1123 if (p)
1124 return -EINVAL;
1125 else
1126 return evdev_revoke(evdev, client, file);
1127
1128 case EVIOCGMASK: {
1129 void __user *codes_ptr;
1130
1131 if (copy_from_user(&mask, p, sizeof(mask)))
1132 return -EFAULT;
1133
1134 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1135 return evdev_get_mask(client,
1136 mask.type, codes_ptr, mask.codes_size,
1137 compat_mode);
1138 }
1139
1140 case EVIOCSMASK: {
1141 const void __user *codes_ptr;
1142
1143 if (copy_from_user(&mask, p, sizeof(mask)))
1144 return -EFAULT;
1145
1146 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1147 return evdev_set_mask(client,
1148 mask.type, codes_ptr, mask.codes_size,
1149 compat_mode);
1150 }
1151
1152 case EVIOCSCLOCKID:
1153 if (copy_from_user(&i, p, sizeof(unsigned int)))
1154 return -EFAULT;
1155
1156 return evdev_set_clk_type(client, i);
1157
1158 case EVIOCGKEYCODE:
1159 return evdev_handle_get_keycode(dev, p);
1160
1161 case EVIOCSKEYCODE:
1162 return evdev_handle_set_keycode(dev, p);
1163
1164 case EVIOCGKEYCODE_V2:
1165 return evdev_handle_get_keycode_v2(dev, p);
1166
1167 case EVIOCSKEYCODE_V2:
1168 return evdev_handle_set_keycode_v2(dev, p);
1169 }
1170
1171 size = _IOC_SIZE(cmd);
1172
1173 /* Now check variable-length commands */
1174#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1175 switch (EVIOC_MASK_SIZE(cmd)) {
1176
1177 case EVIOCGPROP(0):
1178 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1179 size, p, compat_mode);
1180
1181 case EVIOCGMTSLOTS(0):
1182 return evdev_handle_mt_request(dev, size, ip);
1183
1184 case EVIOCGKEY(0):
1185 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1186 KEY_MAX, size, p, compat_mode);
1187
1188 case EVIOCGLED(0):
1189 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1190 LED_MAX, size, p, compat_mode);
1191
1192 case EVIOCGSND(0):
1193 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1194 SND_MAX, size, p, compat_mode);
1195
1196 case EVIOCGSW(0):
1197 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1198 SW_MAX, size, p, compat_mode);
1199
1200 case EVIOCGNAME(0):
1201 return str_to_user(dev->name, size, p);
1202
1203 case EVIOCGPHYS(0):
1204 return str_to_user(dev->phys, size, p);
1205
1206 case EVIOCGUNIQ(0):
1207 return str_to_user(dev->uniq, size, p);
1208
1209 case EVIOC_MASK_SIZE(EVIOCSFF):
1210 if (input_ff_effect_from_user(p, size, &effect))
1211 return -EFAULT;
1212
1213 error = input_ff_upload(dev, &effect, file);
1214 if (error)
1215 return error;
1216
1217 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1218 return -EFAULT;
1219
1220 return 0;
1221 }
1222
1223 /* Multi-number variable-length handlers */
1224 if (_IOC_TYPE(cmd) != 'E')
1225 return -EINVAL;
1226
1227 if (_IOC_DIR(cmd) == _IOC_READ) {
1228
1229 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1230 return handle_eviocgbit(dev,
1231 _IOC_NR(cmd) & EV_MAX, size,
1232 p, compat_mode);
1233
1234 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1235
1236 if (!dev->absinfo)
1237 return -EINVAL;
1238
1239 t = _IOC_NR(cmd) & ABS_MAX;
1240 abs = dev->absinfo[t];
1241
1242 if (copy_to_user(p, &abs, min_t(size_t,
1243 size, sizeof(struct input_absinfo))))
1244 return -EFAULT;
1245
1246 return 0;
1247 }
1248 }
1249
1250 if (_IOC_DIR(cmd) == _IOC_WRITE) {
1251
1252 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1253
1254 if (!dev->absinfo)
1255 return -EINVAL;
1256
1257 t = _IOC_NR(cmd) & ABS_MAX;
1258
1259 if (copy_from_user(&abs, p, min_t(size_t,
1260 size, sizeof(struct input_absinfo))))
1261 return -EFAULT;
1262
1263 if (size < sizeof(struct input_absinfo))
1264 abs.resolution = 0;
1265
1266 /* We can't change number of reserved MT slots */
1267 if (t == ABS_MT_SLOT)
1268 return -EINVAL;
1269
1270 /*
1271 * Take event lock to ensure that we are not
1272 * changing device parameters in the middle
1273 * of event.
1274 */
1275 spin_lock_irq(&dev->event_lock);
1276 dev->absinfo[t] = abs;
1277 spin_unlock_irq(&dev->event_lock);
1278
1279 return 0;
1280 }
1281 }
1282
1283 return -EINVAL;
1284}
1285
1286static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1287 void __user *p, int compat_mode)
1288{
1289 struct evdev_client *client = file->private_data;
1290 struct evdev *evdev = client->evdev;
1291 int retval;
1292
1293 retval = mutex_lock_interruptible(&evdev->mutex);
1294 if (retval)
1295 return retval;
1296
1297 if (!evdev->exist || client->revoked) {
1298 retval = -ENODEV;
1299 goto out;
1300 }
1301
1302 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1303
1304 out:
1305 mutex_unlock(&evdev->mutex);
1306 return retval;
1307}
1308
1309static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1310{
1311 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1312}
1313
1314#ifdef CONFIG_COMPAT
1315static long evdev_ioctl_compat(struct file *file,
1316 unsigned int cmd, unsigned long arg)
1317{
1318 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1319}
1320#endif
1321
1322static const struct file_operations evdev_fops = {
1323 .owner = THIS_MODULE,
1324 .read = evdev_read,
1325 .write = evdev_write,
1326 .poll = evdev_poll,
1327 .open = evdev_open,
1328 .release = evdev_release,
1329 .unlocked_ioctl = evdev_ioctl,
1330#ifdef CONFIG_COMPAT
1331 .compat_ioctl = evdev_ioctl_compat,
1332#endif
1333 .fasync = evdev_fasync,
1334 .flush = evdev_flush,
1335 .llseek = no_llseek,
1336};
1337
1338/*
1339 * Mark device non-existent. This disables writes, ioctls and
1340 * prevents new users from opening the device. Already posted
1341 * blocking reads will stay, however new ones will fail.
1342 */
1343static void evdev_mark_dead(struct evdev *evdev)
1344{
1345 mutex_lock(&evdev->mutex);
1346 evdev->exist = false;
1347 mutex_unlock(&evdev->mutex);
1348}
1349
1350static void evdev_cleanup(struct evdev *evdev)
1351{
1352 struct input_handle *handle = &evdev->handle;
1353
1354 evdev_mark_dead(evdev);
1355 evdev_hangup(evdev);
1356
1357 /* evdev is marked dead so no one else accesses evdev->open */
1358 if (evdev->open) {
1359 input_flush_device(handle, NULL);
1360 input_close_device(handle);
1361 }
1362}
1363
1364/*
1365 * Create new evdev device. Note that input core serializes calls
1366 * to connect and disconnect.
1367 */
1368static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1369 const struct input_device_id *id)
1370{
1371 struct evdev *evdev;
1372 int minor;
1373 int dev_no;
1374 int error;
1375
1376 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1377 if (minor < 0) {
1378 error = minor;
1379 pr_err("failed to reserve new minor: %d\n", error);
1380 return error;
1381 }
1382
1383 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1384 if (!evdev) {
1385 error = -ENOMEM;
1386 goto err_free_minor;
1387 }
1388
1389 INIT_LIST_HEAD(&evdev->client_list);
1390 spin_lock_init(&evdev->client_lock);
1391 mutex_init(&evdev->mutex);
1392 init_waitqueue_head(&evdev->wait);
1393 evdev->exist = true;
1394
1395 dev_no = minor;
1396 /* Normalize device number if it falls into legacy range */
1397 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1398 dev_no -= EVDEV_MINOR_BASE;
1399 dev_set_name(&evdev->dev, "event%d", dev_no);
1400
1401 evdev->handle.dev = input_get_device(dev);
1402 evdev->handle.name = dev_name(&evdev->dev);
1403 evdev->handle.handler = handler;
1404 evdev->handle.private = evdev;
1405
1406 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1407 evdev->dev.class = &input_class;
1408 evdev->dev.parent = &dev->dev;
1409 evdev->dev.release = evdev_free;
1410 device_initialize(&evdev->dev);
1411
1412 error = input_register_handle(&evdev->handle);
1413 if (error)
1414 goto err_free_evdev;
1415
1416 cdev_init(&evdev->cdev, &evdev_fops);
1417
1418 error = cdev_device_add(&evdev->cdev, &evdev->dev);
1419 if (error)
1420 goto err_cleanup_evdev;
1421
1422 return 0;
1423
1424 err_cleanup_evdev:
1425 evdev_cleanup(evdev);
1426 input_unregister_handle(&evdev->handle);
1427 err_free_evdev:
1428 put_device(&evdev->dev);
1429 err_free_minor:
1430 input_free_minor(minor);
1431 return error;
1432}
1433
1434static void evdev_disconnect(struct input_handle *handle)
1435{
1436 struct evdev *evdev = handle->private;
1437
1438 cdev_device_del(&evdev->cdev, &evdev->dev);
1439 evdev_cleanup(evdev);
1440 input_free_minor(MINOR(evdev->dev.devt));
1441 input_unregister_handle(handle);
1442 put_device(&evdev->dev);
1443}
1444
1445static const struct input_device_id evdev_ids[] = {
1446 { .driver_info = 1 }, /* Matches all devices */
1447 { }, /* Terminating zero entry */
1448};
1449
1450MODULE_DEVICE_TABLE(input, evdev_ids);
1451
1452static struct input_handler evdev_handler = {
1453 .event = evdev_event,
1454 .events = evdev_events,
1455 .connect = evdev_connect,
1456 .disconnect = evdev_disconnect,
1457 .legacy_minors = true,
1458 .minor = EVDEV_MINOR_BASE,
1459 .name = "evdev",
1460 .id_table = evdev_ids,
1461};
1462
1463static int __init evdev_init(void)
1464{
1465 return input_register_handler(&evdev_handler);
1466}
1467
1468static void __exit evdev_exit(void)
1469{
1470 input_unregister_handler(&evdev_handler);
1471}
1472
1473module_init(evdev_init);
1474module_exit(evdev_exit);
1475
1476MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
1477MODULE_DESCRIPTION("Input driver event char devices");
1478MODULE_LICENSE("GPL");