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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 cdev_del(&evdev->cdev);
1358
1359 /* evdev is marked dead so no one else accesses evdev->open */
1360 if (evdev->open) {
1361 input_flush_device(handle, NULL);
1362 input_close_device(handle);
1363 }
1364}
1365
1366/*
1367 * Create new evdev device. Note that input core serializes calls
1368 * to connect and disconnect.
1369 */
1370static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1371 const struct input_device_id *id)
1372{
1373 struct evdev *evdev;
1374 int minor;
1375 int dev_no;
1376 int error;
1377
1378 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1379 if (minor < 0) {
1380 error = minor;
1381 pr_err("failed to reserve new minor: %d\n", error);
1382 return error;
1383 }
1384
1385 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1386 if (!evdev) {
1387 error = -ENOMEM;
1388 goto err_free_minor;
1389 }
1390
1391 INIT_LIST_HEAD(&evdev->client_list);
1392 spin_lock_init(&evdev->client_lock);
1393 mutex_init(&evdev->mutex);
1394 init_waitqueue_head(&evdev->wait);
1395 evdev->exist = true;
1396
1397 dev_no = minor;
1398 /* Normalize device number if it falls into legacy range */
1399 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1400 dev_no -= EVDEV_MINOR_BASE;
1401 dev_set_name(&evdev->dev, "event%d", dev_no);
1402
1403 evdev->handle.dev = input_get_device(dev);
1404 evdev->handle.name = dev_name(&evdev->dev);
1405 evdev->handle.handler = handler;
1406 evdev->handle.private = evdev;
1407
1408 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1409 evdev->dev.class = &input_class;
1410 evdev->dev.parent = &dev->dev;
1411 evdev->dev.release = evdev_free;
1412 device_initialize(&evdev->dev);
1413
1414 error = input_register_handle(&evdev->handle);
1415 if (error)
1416 goto err_free_evdev;
1417
1418 cdev_init(&evdev->cdev, &evdev_fops);
1419 evdev->cdev.kobj.parent = &evdev->dev.kobj;
1420 error = cdev_add(&evdev->cdev, evdev->dev.devt, 1);
1421 if (error)
1422 goto err_unregister_handle;
1423
1424 error = device_add(&evdev->dev);
1425 if (error)
1426 goto err_cleanup_evdev;
1427
1428 return 0;
1429
1430 err_cleanup_evdev:
1431 evdev_cleanup(evdev);
1432 err_unregister_handle:
1433 input_unregister_handle(&evdev->handle);
1434 err_free_evdev:
1435 put_device(&evdev->dev);
1436 err_free_minor:
1437 input_free_minor(minor);
1438 return error;
1439}
1440
1441static void evdev_disconnect(struct input_handle *handle)
1442{
1443 struct evdev *evdev = handle->private;
1444
1445 device_del(&evdev->dev);
1446 evdev_cleanup(evdev);
1447 input_free_minor(MINOR(evdev->dev.devt));
1448 input_unregister_handle(handle);
1449 put_device(&evdev->dev);
1450}
1451
1452static const struct input_device_id evdev_ids[] = {
1453 { .driver_info = 1 }, /* Matches all devices */
1454 { }, /* Terminating zero entry */
1455};
1456
1457MODULE_DEVICE_TABLE(input, evdev_ids);
1458
1459static struct input_handler evdev_handler = {
1460 .event = evdev_event,
1461 .events = evdev_events,
1462 .connect = evdev_connect,
1463 .disconnect = evdev_disconnect,
1464 .legacy_minors = true,
1465 .minor = EVDEV_MINOR_BASE,
1466 .name = "evdev",
1467 .id_table = evdev_ids,
1468};
1469
1470static int __init evdev_init(void)
1471{
1472 return input_register_handler(&evdev_handler);
1473}
1474
1475static void __exit evdev_exit(void)
1476{
1477 input_unregister_handler(&evdev_handler);
1478}
1479
1480module_init(evdev_init);
1481module_exit(evdev_exit);
1482
1483MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1484MODULE_DESCRIPTION("Input driver event char devices");
1485MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Event char devices, giving access to raw input device events.
4 *
5 * Copyright (c) 1999-2002 Vojtech Pavlik
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#define EVDEV_MINOR_BASE 64
11#define EVDEV_MINORS 32
12#define EVDEV_MIN_BUFFER_SIZE 64U
13#define EVDEV_BUF_PACKETS 8
14
15#include <linux/poll.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19#include <linux/mm.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/input/mt.h>
23#include <linux/major.h>
24#include <linux/device.h>
25#include <linux/cdev.h>
26#include "input-compat.h"
27
28struct evdev {
29 int open;
30 struct input_handle handle;
31 wait_queue_head_t wait;
32 struct evdev_client __rcu *grab;
33 struct list_head client_list;
34 spinlock_t client_lock; /* protects client_list */
35 struct mutex mutex;
36 struct device dev;
37 struct cdev cdev;
38 bool exist;
39};
40
41struct evdev_client {
42 unsigned int head;
43 unsigned int tail;
44 unsigned int packet_head; /* [future] position of the first element of next packet */
45 spinlock_t buffer_lock; /* protects access to buffer, head and tail */
46 struct fasync_struct *fasync;
47 struct evdev *evdev;
48 struct list_head node;
49 enum input_clock_type clk_type;
50 bool revoked;
51 unsigned long *evmasks[EV_CNT];
52 unsigned int bufsize;
53 struct input_event buffer[];
54};
55
56static size_t evdev_get_mask_cnt(unsigned int type)
57{
58 static const size_t counts[EV_CNT] = {
59 /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
60 [EV_SYN] = EV_CNT,
61 [EV_KEY] = KEY_CNT,
62 [EV_REL] = REL_CNT,
63 [EV_ABS] = ABS_CNT,
64 [EV_MSC] = MSC_CNT,
65 [EV_SW] = SW_CNT,
66 [EV_LED] = LED_CNT,
67 [EV_SND] = SND_CNT,
68 [EV_FF] = FF_CNT,
69 };
70
71 return (type < EV_CNT) ? counts[type] : 0;
72}
73
74/* requires the buffer lock to be held */
75static bool __evdev_is_filtered(struct evdev_client *client,
76 unsigned int type,
77 unsigned int code)
78{
79 unsigned long *mask;
80 size_t cnt;
81
82 /* EV_SYN and unknown codes are never filtered */
83 if (type == EV_SYN || type >= EV_CNT)
84 return false;
85
86 /* first test whether the type is filtered */
87 mask = client->evmasks[0];
88 if (mask && !test_bit(type, mask))
89 return true;
90
91 /* unknown values are never filtered */
92 cnt = evdev_get_mask_cnt(type);
93 if (!cnt || code >= cnt)
94 return false;
95
96 mask = client->evmasks[type];
97 return mask && !test_bit(code, mask);
98}
99
100/* flush queued events of type @type, caller must hold client->buffer_lock */
101static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
102{
103 unsigned int i, head, num;
104 unsigned int mask = client->bufsize - 1;
105 bool is_report;
106 struct input_event *ev;
107
108 BUG_ON(type == EV_SYN);
109
110 head = client->tail;
111 client->packet_head = client->tail;
112
113 /* init to 1 so a leading SYN_REPORT will not be dropped */
114 num = 1;
115
116 for (i = client->tail; i != client->head; i = (i + 1) & mask) {
117 ev = &client->buffer[i];
118 is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
119
120 if (ev->type == type) {
121 /* drop matched entry */
122 continue;
123 } else if (is_report && !num) {
124 /* drop empty SYN_REPORT groups */
125 continue;
126 } else if (head != i) {
127 /* move entry to fill the gap */
128 client->buffer[head] = *ev;
129 }
130
131 num++;
132 head = (head + 1) & mask;
133
134 if (is_report) {
135 num = 0;
136 client->packet_head = head;
137 }
138 }
139
140 client->head = head;
141}
142
143static void __evdev_queue_syn_dropped(struct evdev_client *client)
144{
145 ktime_t *ev_time = input_get_timestamp(client->evdev->handle.dev);
146 struct timespec64 ts = ktime_to_timespec64(ev_time[client->clk_type]);
147 struct input_event ev;
148
149 ev.input_event_sec = ts.tv_sec;
150 ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
151 ev.type = EV_SYN;
152 ev.code = SYN_DROPPED;
153 ev.value = 0;
154
155 client->buffer[client->head++] = ev;
156 client->head &= client->bufsize - 1;
157
158 if (unlikely(client->head == client->tail)) {
159 /* drop queue but keep our SYN_DROPPED event */
160 client->tail = (client->head - 1) & (client->bufsize - 1);
161 client->packet_head = client->tail;
162 }
163}
164
165static void evdev_queue_syn_dropped(struct evdev_client *client)
166{
167 unsigned long flags;
168
169 spin_lock_irqsave(&client->buffer_lock, flags);
170 __evdev_queue_syn_dropped(client);
171 spin_unlock_irqrestore(&client->buffer_lock, flags);
172}
173
174static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
175{
176 unsigned long flags;
177 enum input_clock_type clk_type;
178
179 switch (clkid) {
180
181 case CLOCK_REALTIME:
182 clk_type = INPUT_CLK_REAL;
183 break;
184 case CLOCK_MONOTONIC:
185 clk_type = INPUT_CLK_MONO;
186 break;
187 case CLOCK_BOOTTIME:
188 clk_type = INPUT_CLK_BOOT;
189 break;
190 default:
191 return -EINVAL;
192 }
193
194 if (client->clk_type != clk_type) {
195 client->clk_type = clk_type;
196
197 /*
198 * Flush pending events and queue SYN_DROPPED event,
199 * but only if the queue is not empty.
200 */
201 spin_lock_irqsave(&client->buffer_lock, flags);
202
203 if (client->head != client->tail) {
204 client->packet_head = client->head = client->tail;
205 __evdev_queue_syn_dropped(client);
206 }
207
208 spin_unlock_irqrestore(&client->buffer_lock, flags);
209 }
210
211 return 0;
212}
213
214static void __pass_event(struct evdev_client *client,
215 const struct input_event *event)
216{
217 client->buffer[client->head++] = *event;
218 client->head &= client->bufsize - 1;
219
220 if (unlikely(client->head == client->tail)) {
221 /*
222 * This effectively "drops" all unconsumed events, leaving
223 * EV_SYN/SYN_DROPPED plus the newest event in the queue.
224 */
225 client->tail = (client->head - 2) & (client->bufsize - 1);
226
227 client->buffer[client->tail] = (struct input_event) {
228 .input_event_sec = event->input_event_sec,
229 .input_event_usec = event->input_event_usec,
230 .type = EV_SYN,
231 .code = SYN_DROPPED,
232 .value = 0,
233 };
234
235 client->packet_head = client->tail;
236 }
237
238 if (event->type == EV_SYN && event->code == SYN_REPORT) {
239 client->packet_head = client->head;
240 kill_fasync(&client->fasync, SIGIO, POLL_IN);
241 }
242}
243
244static void evdev_pass_values(struct evdev_client *client,
245 const struct input_value *vals, unsigned int count,
246 ktime_t *ev_time)
247{
248 struct evdev *evdev = client->evdev;
249 const struct input_value *v;
250 struct input_event event;
251 struct timespec64 ts;
252 bool wakeup = false;
253
254 if (client->revoked)
255 return;
256
257 ts = ktime_to_timespec64(ev_time[client->clk_type]);
258 event.input_event_sec = ts.tv_sec;
259 event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
260
261 /* Interrupts are disabled, just acquire the lock. */
262 spin_lock(&client->buffer_lock);
263
264 for (v = vals; v != vals + count; v++) {
265 if (__evdev_is_filtered(client, v->type, v->code))
266 continue;
267
268 if (v->type == EV_SYN && v->code == SYN_REPORT) {
269 /* drop empty SYN_REPORT */
270 if (client->packet_head == client->head)
271 continue;
272
273 wakeup = true;
274 }
275
276 event.type = v->type;
277 event.code = v->code;
278 event.value = v->value;
279 __pass_event(client, &event);
280 }
281
282 spin_unlock(&client->buffer_lock);
283
284 if (wakeup)
285 wake_up_interruptible_poll(&evdev->wait,
286 EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM);
287}
288
289/*
290 * Pass incoming events to all connected clients.
291 */
292static void evdev_events(struct input_handle *handle,
293 const struct input_value *vals, unsigned int count)
294{
295 struct evdev *evdev = handle->private;
296 struct evdev_client *client;
297 ktime_t *ev_time = input_get_timestamp(handle->dev);
298
299 rcu_read_lock();
300
301 client = rcu_dereference(evdev->grab);
302
303 if (client)
304 evdev_pass_values(client, vals, count, ev_time);
305 else
306 list_for_each_entry_rcu(client, &evdev->client_list, node)
307 evdev_pass_values(client, vals, count, ev_time);
308
309 rcu_read_unlock();
310}
311
312/*
313 * Pass incoming event to all connected clients.
314 */
315static void evdev_event(struct input_handle *handle,
316 unsigned int type, unsigned int code, int value)
317{
318 struct input_value vals[] = { { type, code, value } };
319
320 evdev_events(handle, vals, 1);
321}
322
323static int evdev_fasync(int fd, struct file *file, int on)
324{
325 struct evdev_client *client = file->private_data;
326
327 return fasync_helper(fd, file, on, &client->fasync);
328}
329
330static void evdev_free(struct device *dev)
331{
332 struct evdev *evdev = container_of(dev, struct evdev, dev);
333
334 input_put_device(evdev->handle.dev);
335 kfree(evdev);
336}
337
338/*
339 * Grabs an event device (along with underlying input device).
340 * This function is called with evdev->mutex taken.
341 */
342static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
343{
344 int error;
345
346 if (evdev->grab)
347 return -EBUSY;
348
349 error = input_grab_device(&evdev->handle);
350 if (error)
351 return error;
352
353 rcu_assign_pointer(evdev->grab, client);
354
355 return 0;
356}
357
358static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
359{
360 struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
361 lockdep_is_held(&evdev->mutex));
362
363 if (grab != client)
364 return -EINVAL;
365
366 rcu_assign_pointer(evdev->grab, NULL);
367 synchronize_rcu();
368 input_release_device(&evdev->handle);
369
370 return 0;
371}
372
373static void evdev_attach_client(struct evdev *evdev,
374 struct evdev_client *client)
375{
376 spin_lock(&evdev->client_lock);
377 list_add_tail_rcu(&client->node, &evdev->client_list);
378 spin_unlock(&evdev->client_lock);
379}
380
381static void evdev_detach_client(struct evdev *evdev,
382 struct evdev_client *client)
383{
384 spin_lock(&evdev->client_lock);
385 list_del_rcu(&client->node);
386 spin_unlock(&evdev->client_lock);
387 synchronize_rcu();
388}
389
390static int evdev_open_device(struct evdev *evdev)
391{
392 int retval;
393
394 retval = mutex_lock_interruptible(&evdev->mutex);
395 if (retval)
396 return retval;
397
398 if (!evdev->exist)
399 retval = -ENODEV;
400 else if (!evdev->open++) {
401 retval = input_open_device(&evdev->handle);
402 if (retval)
403 evdev->open--;
404 }
405
406 mutex_unlock(&evdev->mutex);
407 return retval;
408}
409
410static void evdev_close_device(struct evdev *evdev)
411{
412 mutex_lock(&evdev->mutex);
413
414 if (evdev->exist && !--evdev->open)
415 input_close_device(&evdev->handle);
416
417 mutex_unlock(&evdev->mutex);
418}
419
420/*
421 * Wake up users waiting for IO so they can disconnect from
422 * dead device.
423 */
424static void evdev_hangup(struct evdev *evdev)
425{
426 struct evdev_client *client;
427
428 spin_lock(&evdev->client_lock);
429 list_for_each_entry(client, &evdev->client_list, node)
430 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
431 spin_unlock(&evdev->client_lock);
432
433 wake_up_interruptible_poll(&evdev->wait, EPOLLHUP | EPOLLERR);
434}
435
436static int evdev_release(struct inode *inode, struct file *file)
437{
438 struct evdev_client *client = file->private_data;
439 struct evdev *evdev = client->evdev;
440 unsigned int i;
441
442 mutex_lock(&evdev->mutex);
443
444 if (evdev->exist && !client->revoked)
445 input_flush_device(&evdev->handle, file);
446
447 evdev_ungrab(evdev, client);
448 mutex_unlock(&evdev->mutex);
449
450 evdev_detach_client(evdev, client);
451
452 for (i = 0; i < EV_CNT; ++i)
453 bitmap_free(client->evmasks[i]);
454
455 kvfree(client);
456
457 evdev_close_device(evdev);
458
459 return 0;
460}
461
462static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
463{
464 unsigned int n_events =
465 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
466 EVDEV_MIN_BUFFER_SIZE);
467
468 return roundup_pow_of_two(n_events);
469}
470
471static int evdev_open(struct inode *inode, struct file *file)
472{
473 struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
474 unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
475 struct evdev_client *client;
476 int error;
477
478 client = kvzalloc(struct_size(client, buffer, bufsize), GFP_KERNEL);
479 if (!client)
480 return -ENOMEM;
481
482 client->bufsize = bufsize;
483 spin_lock_init(&client->buffer_lock);
484 client->evdev = evdev;
485 evdev_attach_client(evdev, client);
486
487 error = evdev_open_device(evdev);
488 if (error)
489 goto err_free_client;
490
491 file->private_data = client;
492 stream_open(inode, file);
493
494 return 0;
495
496 err_free_client:
497 evdev_detach_client(evdev, client);
498 kvfree(client);
499 return error;
500}
501
502static ssize_t evdev_write(struct file *file, const char __user *buffer,
503 size_t count, loff_t *ppos)
504{
505 struct evdev_client *client = file->private_data;
506 struct evdev *evdev = client->evdev;
507 struct input_event event;
508 int retval = 0;
509
510 if (count != 0 && count < input_event_size())
511 return -EINVAL;
512
513 retval = mutex_lock_interruptible(&evdev->mutex);
514 if (retval)
515 return retval;
516
517 if (!evdev->exist || client->revoked) {
518 retval = -ENODEV;
519 goto out;
520 }
521
522 while (retval + input_event_size() <= count) {
523
524 if (input_event_from_user(buffer + retval, &event)) {
525 retval = -EFAULT;
526 goto out;
527 }
528 retval += input_event_size();
529
530 input_inject_event(&evdev->handle,
531 event.type, event.code, event.value);
532 cond_resched();
533 }
534
535 out:
536 mutex_unlock(&evdev->mutex);
537 return retval;
538}
539
540static int evdev_fetch_next_event(struct evdev_client *client,
541 struct input_event *event)
542{
543 int have_event;
544
545 spin_lock_irq(&client->buffer_lock);
546
547 have_event = client->packet_head != client->tail;
548 if (have_event) {
549 *event = client->buffer[client->tail++];
550 client->tail &= client->bufsize - 1;
551 }
552
553 spin_unlock_irq(&client->buffer_lock);
554
555 return have_event;
556}
557
558static ssize_t evdev_read(struct file *file, char __user *buffer,
559 size_t count, loff_t *ppos)
560{
561 struct evdev_client *client = file->private_data;
562 struct evdev *evdev = client->evdev;
563 struct input_event event;
564 size_t read = 0;
565 int error;
566
567 if (count != 0 && count < input_event_size())
568 return -EINVAL;
569
570 for (;;) {
571 if (!evdev->exist || client->revoked)
572 return -ENODEV;
573
574 if (client->packet_head == client->tail &&
575 (file->f_flags & O_NONBLOCK))
576 return -EAGAIN;
577
578 /*
579 * count == 0 is special - no IO is done but we check
580 * for error conditions (see above).
581 */
582 if (count == 0)
583 break;
584
585 while (read + input_event_size() <= count &&
586 evdev_fetch_next_event(client, &event)) {
587
588 if (input_event_to_user(buffer + read, &event))
589 return -EFAULT;
590
591 read += input_event_size();
592 }
593
594 if (read)
595 break;
596
597 if (!(file->f_flags & O_NONBLOCK)) {
598 error = wait_event_interruptible(evdev->wait,
599 client->packet_head != client->tail ||
600 !evdev->exist || client->revoked);
601 if (error)
602 return error;
603 }
604 }
605
606 return read;
607}
608
609/* No kernel lock - fine */
610static __poll_t evdev_poll(struct file *file, poll_table *wait)
611{
612 struct evdev_client *client = file->private_data;
613 struct evdev *evdev = client->evdev;
614 __poll_t mask;
615
616 poll_wait(file, &evdev->wait, wait);
617
618 if (evdev->exist && !client->revoked)
619 mask = EPOLLOUT | EPOLLWRNORM;
620 else
621 mask = EPOLLHUP | EPOLLERR;
622
623 if (client->packet_head != client->tail)
624 mask |= EPOLLIN | EPOLLRDNORM;
625
626 return mask;
627}
628
629#ifdef CONFIG_COMPAT
630
631#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
632#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
633
634#ifdef __BIG_ENDIAN
635static int bits_to_user(unsigned long *bits, unsigned int maxbit,
636 unsigned int maxlen, void __user *p, int compat)
637{
638 int len, i;
639
640 if (compat) {
641 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
642 if (len > maxlen)
643 len = maxlen;
644
645 for (i = 0; i < len / sizeof(compat_long_t); i++)
646 if (copy_to_user((compat_long_t __user *) p + i,
647 (compat_long_t *) bits +
648 i + 1 - ((i % 2) << 1),
649 sizeof(compat_long_t)))
650 return -EFAULT;
651 } else {
652 len = BITS_TO_LONGS(maxbit) * sizeof(long);
653 if (len > maxlen)
654 len = maxlen;
655
656 if (copy_to_user(p, bits, len))
657 return -EFAULT;
658 }
659
660 return len;
661}
662
663static int bits_from_user(unsigned long *bits, unsigned int maxbit,
664 unsigned int maxlen, const void __user *p, int compat)
665{
666 int len, i;
667
668 if (compat) {
669 if (maxlen % sizeof(compat_long_t))
670 return -EINVAL;
671
672 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
673 if (len > maxlen)
674 len = maxlen;
675
676 for (i = 0; i < len / sizeof(compat_long_t); i++)
677 if (copy_from_user((compat_long_t *) bits +
678 i + 1 - ((i % 2) << 1),
679 (compat_long_t __user *) p + i,
680 sizeof(compat_long_t)))
681 return -EFAULT;
682 if (i % 2)
683 *((compat_long_t *) bits + i - 1) = 0;
684
685 } else {
686 if (maxlen % sizeof(long))
687 return -EINVAL;
688
689 len = BITS_TO_LONGS(maxbit) * sizeof(long);
690 if (len > maxlen)
691 len = maxlen;
692
693 if (copy_from_user(bits, p, len))
694 return -EFAULT;
695 }
696
697 return len;
698}
699
700#else
701
702static int bits_to_user(unsigned long *bits, unsigned int maxbit,
703 unsigned int maxlen, void __user *p, int compat)
704{
705 int len = compat ?
706 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
707 BITS_TO_LONGS(maxbit) * sizeof(long);
708
709 if (len > maxlen)
710 len = maxlen;
711
712 return copy_to_user(p, bits, len) ? -EFAULT : len;
713}
714
715static int bits_from_user(unsigned long *bits, unsigned int maxbit,
716 unsigned int maxlen, const void __user *p, int compat)
717{
718 size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
719 int len;
720
721 if (maxlen % chunk_size)
722 return -EINVAL;
723
724 len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
725 len *= chunk_size;
726 if (len > maxlen)
727 len = maxlen;
728
729 return copy_from_user(bits, p, len) ? -EFAULT : len;
730}
731
732#endif /* __BIG_ENDIAN */
733
734#else
735
736static int bits_to_user(unsigned long *bits, unsigned int maxbit,
737 unsigned int maxlen, void __user *p, int compat)
738{
739 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
740
741 if (len > maxlen)
742 len = maxlen;
743
744 return copy_to_user(p, bits, len) ? -EFAULT : len;
745}
746
747static int bits_from_user(unsigned long *bits, unsigned int maxbit,
748 unsigned int maxlen, const void __user *p, int compat)
749{
750 int len;
751
752 if (maxlen % sizeof(long))
753 return -EINVAL;
754
755 len = BITS_TO_LONGS(maxbit) * sizeof(long);
756 if (len > maxlen)
757 len = maxlen;
758
759 return copy_from_user(bits, p, len) ? -EFAULT : len;
760}
761
762#endif /* CONFIG_COMPAT */
763
764static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
765{
766 int len;
767
768 if (!str)
769 return -ENOENT;
770
771 len = strlen(str) + 1;
772 if (len > maxlen)
773 len = maxlen;
774
775 return copy_to_user(p, str, len) ? -EFAULT : len;
776}
777
778static int handle_eviocgbit(struct input_dev *dev,
779 unsigned int type, unsigned int size,
780 void __user *p, int compat_mode)
781{
782 unsigned long *bits;
783 int len;
784
785 switch (type) {
786
787 case 0: bits = dev->evbit; len = EV_MAX; break;
788 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
789 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
790 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
791 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
792 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
793 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
794 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
795 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
796 default: return -EINVAL;
797 }
798
799 return bits_to_user(bits, len, size, p, compat_mode);
800}
801
802static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
803{
804 struct input_keymap_entry ke = {
805 .len = sizeof(unsigned int),
806 .flags = 0,
807 };
808 int __user *ip = (int __user *)p;
809 int error;
810
811 /* legacy case */
812 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
813 return -EFAULT;
814
815 error = input_get_keycode(dev, &ke);
816 if (error)
817 return error;
818
819 if (put_user(ke.keycode, ip + 1))
820 return -EFAULT;
821
822 return 0;
823}
824
825static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
826{
827 struct input_keymap_entry ke;
828 int error;
829
830 if (copy_from_user(&ke, p, sizeof(ke)))
831 return -EFAULT;
832
833 error = input_get_keycode(dev, &ke);
834 if (error)
835 return error;
836
837 if (copy_to_user(p, &ke, sizeof(ke)))
838 return -EFAULT;
839
840 return 0;
841}
842
843static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
844{
845 struct input_keymap_entry ke = {
846 .len = sizeof(unsigned int),
847 .flags = 0,
848 };
849 int __user *ip = (int __user *)p;
850
851 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
852 return -EFAULT;
853
854 if (get_user(ke.keycode, ip + 1))
855 return -EFAULT;
856
857 return input_set_keycode(dev, &ke);
858}
859
860static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
861{
862 struct input_keymap_entry ke;
863
864 if (copy_from_user(&ke, p, sizeof(ke)))
865 return -EFAULT;
866
867 if (ke.len > sizeof(ke.scancode))
868 return -EINVAL;
869
870 return input_set_keycode(dev, &ke);
871}
872
873/*
874 * If we transfer state to the user, we should flush all pending events
875 * of the same type from the client's queue. Otherwise, they might end up
876 * with duplicate events, which can screw up client's state tracking.
877 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
878 * event so user-space will notice missing events.
879 *
880 * LOCKING:
881 * We need to take event_lock before buffer_lock to avoid dead-locks. But we
882 * need the even_lock only to guarantee consistent state. We can safely release
883 * it while flushing the queue. This allows input-core to handle filters while
884 * we flush the queue.
885 */
886static int evdev_handle_get_val(struct evdev_client *client,
887 struct input_dev *dev, unsigned int type,
888 unsigned long *bits, unsigned int maxbit,
889 unsigned int maxlen, void __user *p,
890 int compat)
891{
892 int ret;
893 unsigned long *mem;
894
895 mem = bitmap_alloc(maxbit, GFP_KERNEL);
896 if (!mem)
897 return -ENOMEM;
898
899 spin_lock_irq(&dev->event_lock);
900 spin_lock(&client->buffer_lock);
901
902 bitmap_copy(mem, bits, maxbit);
903
904 spin_unlock(&dev->event_lock);
905
906 __evdev_flush_queue(client, type);
907
908 spin_unlock_irq(&client->buffer_lock);
909
910 ret = bits_to_user(mem, maxbit, maxlen, p, compat);
911 if (ret < 0)
912 evdev_queue_syn_dropped(client);
913
914 bitmap_free(mem);
915
916 return ret;
917}
918
919static int evdev_handle_mt_request(struct input_dev *dev,
920 unsigned int size,
921 int __user *ip)
922{
923 const struct input_mt *mt = dev->mt;
924 unsigned int code;
925 int max_slots;
926 int i;
927
928 if (get_user(code, &ip[0]))
929 return -EFAULT;
930 if (!mt || !input_is_mt_value(code))
931 return -EINVAL;
932
933 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
934 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
935 int value = input_mt_get_value(&mt->slots[i], code);
936 if (put_user(value, &ip[1 + i]))
937 return -EFAULT;
938 }
939
940 return 0;
941}
942
943static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
944 struct file *file)
945{
946 client->revoked = true;
947 evdev_ungrab(evdev, client);
948 input_flush_device(&evdev->handle, file);
949 wake_up_interruptible_poll(&evdev->wait, EPOLLHUP | EPOLLERR);
950
951 return 0;
952}
953
954/* must be called with evdev-mutex held */
955static int evdev_set_mask(struct evdev_client *client,
956 unsigned int type,
957 const void __user *codes,
958 u32 codes_size,
959 int compat)
960{
961 unsigned long flags, *mask, *oldmask;
962 size_t cnt;
963 int error;
964
965 /* we allow unknown types and 'codes_size > size' for forward-compat */
966 cnt = evdev_get_mask_cnt(type);
967 if (!cnt)
968 return 0;
969
970 mask = bitmap_zalloc(cnt, GFP_KERNEL);
971 if (!mask)
972 return -ENOMEM;
973
974 error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
975 if (error < 0) {
976 bitmap_free(mask);
977 return error;
978 }
979
980 spin_lock_irqsave(&client->buffer_lock, flags);
981 oldmask = client->evmasks[type];
982 client->evmasks[type] = mask;
983 spin_unlock_irqrestore(&client->buffer_lock, flags);
984
985 bitmap_free(oldmask);
986
987 return 0;
988}
989
990/* must be called with evdev-mutex held */
991static int evdev_get_mask(struct evdev_client *client,
992 unsigned int type,
993 void __user *codes,
994 u32 codes_size,
995 int compat)
996{
997 unsigned long *mask;
998 size_t cnt, size, xfer_size;
999 int i;
1000 int error;
1001
1002 /* we allow unknown types and 'codes_size > size' for forward-compat */
1003 cnt = evdev_get_mask_cnt(type);
1004 size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1005 xfer_size = min_t(size_t, codes_size, size);
1006
1007 if (cnt > 0) {
1008 mask = client->evmasks[type];
1009 if (mask) {
1010 error = bits_to_user(mask, cnt - 1,
1011 xfer_size, codes, compat);
1012 if (error < 0)
1013 return error;
1014 } else {
1015 /* fake mask with all bits set */
1016 for (i = 0; i < xfer_size; i++)
1017 if (put_user(0xffU, (u8 __user *)codes + i))
1018 return -EFAULT;
1019 }
1020 }
1021
1022 if (xfer_size < codes_size)
1023 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1024 return -EFAULT;
1025
1026 return 0;
1027}
1028
1029static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1030 void __user *p, int compat_mode)
1031{
1032 struct evdev_client *client = file->private_data;
1033 struct evdev *evdev = client->evdev;
1034 struct input_dev *dev = evdev->handle.dev;
1035 struct input_absinfo abs;
1036 struct input_mask mask;
1037 struct ff_effect effect;
1038 int __user *ip = (int __user *)p;
1039 unsigned int i, t, u, v;
1040 unsigned int size;
1041 int error;
1042
1043 /* First we check for fixed-length commands */
1044 switch (cmd) {
1045
1046 case EVIOCGVERSION:
1047 return put_user(EV_VERSION, ip);
1048
1049 case EVIOCGID:
1050 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1051 return -EFAULT;
1052 return 0;
1053
1054 case EVIOCGREP:
1055 if (!test_bit(EV_REP, dev->evbit))
1056 return -ENOSYS;
1057 if (put_user(dev->rep[REP_DELAY], ip))
1058 return -EFAULT;
1059 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1060 return -EFAULT;
1061 return 0;
1062
1063 case EVIOCSREP:
1064 if (!test_bit(EV_REP, dev->evbit))
1065 return -ENOSYS;
1066 if (get_user(u, ip))
1067 return -EFAULT;
1068 if (get_user(v, ip + 1))
1069 return -EFAULT;
1070
1071 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1072 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1073
1074 return 0;
1075
1076 case EVIOCRMFF:
1077 return input_ff_erase(dev, (int)(unsigned long) p, file);
1078
1079 case EVIOCGEFFECTS:
1080 i = test_bit(EV_FF, dev->evbit) ?
1081 dev->ff->max_effects : 0;
1082 if (put_user(i, ip))
1083 return -EFAULT;
1084 return 0;
1085
1086 case EVIOCGRAB:
1087 if (p)
1088 return evdev_grab(evdev, client);
1089 else
1090 return evdev_ungrab(evdev, client);
1091
1092 case EVIOCREVOKE:
1093 if (p)
1094 return -EINVAL;
1095 else
1096 return evdev_revoke(evdev, client, file);
1097
1098 case EVIOCGMASK: {
1099 void __user *codes_ptr;
1100
1101 if (copy_from_user(&mask, p, sizeof(mask)))
1102 return -EFAULT;
1103
1104 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1105 return evdev_get_mask(client,
1106 mask.type, codes_ptr, mask.codes_size,
1107 compat_mode);
1108 }
1109
1110 case EVIOCSMASK: {
1111 const void __user *codes_ptr;
1112
1113 if (copy_from_user(&mask, p, sizeof(mask)))
1114 return -EFAULT;
1115
1116 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1117 return evdev_set_mask(client,
1118 mask.type, codes_ptr, mask.codes_size,
1119 compat_mode);
1120 }
1121
1122 case EVIOCSCLOCKID:
1123 if (copy_from_user(&i, p, sizeof(unsigned int)))
1124 return -EFAULT;
1125
1126 return evdev_set_clk_type(client, i);
1127
1128 case EVIOCGKEYCODE:
1129 return evdev_handle_get_keycode(dev, p);
1130
1131 case EVIOCSKEYCODE:
1132 return evdev_handle_set_keycode(dev, p);
1133
1134 case EVIOCGKEYCODE_V2:
1135 return evdev_handle_get_keycode_v2(dev, p);
1136
1137 case EVIOCSKEYCODE_V2:
1138 return evdev_handle_set_keycode_v2(dev, p);
1139 }
1140
1141 size = _IOC_SIZE(cmd);
1142
1143 /* Now check variable-length commands */
1144#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1145 switch (EVIOC_MASK_SIZE(cmd)) {
1146
1147 case EVIOCGPROP(0):
1148 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1149 size, p, compat_mode);
1150
1151 case EVIOCGMTSLOTS(0):
1152 return evdev_handle_mt_request(dev, size, ip);
1153
1154 case EVIOCGKEY(0):
1155 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1156 KEY_MAX, size, p, compat_mode);
1157
1158 case EVIOCGLED(0):
1159 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1160 LED_MAX, size, p, compat_mode);
1161
1162 case EVIOCGSND(0):
1163 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1164 SND_MAX, size, p, compat_mode);
1165
1166 case EVIOCGSW(0):
1167 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1168 SW_MAX, size, p, compat_mode);
1169
1170 case EVIOCGNAME(0):
1171 return str_to_user(dev->name, size, p);
1172
1173 case EVIOCGPHYS(0):
1174 return str_to_user(dev->phys, size, p);
1175
1176 case EVIOCGUNIQ(0):
1177 return str_to_user(dev->uniq, size, p);
1178
1179 case EVIOC_MASK_SIZE(EVIOCSFF):
1180 if (input_ff_effect_from_user(p, size, &effect))
1181 return -EFAULT;
1182
1183 error = input_ff_upload(dev, &effect, file);
1184 if (error)
1185 return error;
1186
1187 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1188 return -EFAULT;
1189
1190 return 0;
1191 }
1192
1193 /* Multi-number variable-length handlers */
1194 if (_IOC_TYPE(cmd) != 'E')
1195 return -EINVAL;
1196
1197 if (_IOC_DIR(cmd) == _IOC_READ) {
1198
1199 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1200 return handle_eviocgbit(dev,
1201 _IOC_NR(cmd) & EV_MAX, size,
1202 p, compat_mode);
1203
1204 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1205
1206 if (!dev->absinfo)
1207 return -EINVAL;
1208
1209 t = _IOC_NR(cmd) & ABS_MAX;
1210 abs = dev->absinfo[t];
1211
1212 if (copy_to_user(p, &abs, min_t(size_t,
1213 size, sizeof(struct input_absinfo))))
1214 return -EFAULT;
1215
1216 return 0;
1217 }
1218 }
1219
1220 if (_IOC_DIR(cmd) == _IOC_WRITE) {
1221
1222 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1223
1224 if (!dev->absinfo)
1225 return -EINVAL;
1226
1227 t = _IOC_NR(cmd) & ABS_MAX;
1228
1229 if (copy_from_user(&abs, p, min_t(size_t,
1230 size, sizeof(struct input_absinfo))))
1231 return -EFAULT;
1232
1233 if (size < sizeof(struct input_absinfo))
1234 abs.resolution = 0;
1235
1236 /* We can't change number of reserved MT slots */
1237 if (t == ABS_MT_SLOT)
1238 return -EINVAL;
1239
1240 /*
1241 * Take event lock to ensure that we are not
1242 * changing device parameters in the middle
1243 * of event.
1244 */
1245 spin_lock_irq(&dev->event_lock);
1246 dev->absinfo[t] = abs;
1247 spin_unlock_irq(&dev->event_lock);
1248
1249 return 0;
1250 }
1251 }
1252
1253 return -EINVAL;
1254}
1255
1256static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1257 void __user *p, int compat_mode)
1258{
1259 struct evdev_client *client = file->private_data;
1260 struct evdev *evdev = client->evdev;
1261 int retval;
1262
1263 retval = mutex_lock_interruptible(&evdev->mutex);
1264 if (retval)
1265 return retval;
1266
1267 if (!evdev->exist || client->revoked) {
1268 retval = -ENODEV;
1269 goto out;
1270 }
1271
1272 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1273
1274 out:
1275 mutex_unlock(&evdev->mutex);
1276 return retval;
1277}
1278
1279static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1280{
1281 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1282}
1283
1284#ifdef CONFIG_COMPAT
1285static long evdev_ioctl_compat(struct file *file,
1286 unsigned int cmd, unsigned long arg)
1287{
1288 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1289}
1290#endif
1291
1292static const struct file_operations evdev_fops = {
1293 .owner = THIS_MODULE,
1294 .read = evdev_read,
1295 .write = evdev_write,
1296 .poll = evdev_poll,
1297 .open = evdev_open,
1298 .release = evdev_release,
1299 .unlocked_ioctl = evdev_ioctl,
1300#ifdef CONFIG_COMPAT
1301 .compat_ioctl = evdev_ioctl_compat,
1302#endif
1303 .fasync = evdev_fasync,
1304 .llseek = no_llseek,
1305};
1306
1307/*
1308 * Mark device non-existent. This disables writes, ioctls and
1309 * prevents new users from opening the device. Already posted
1310 * blocking reads will stay, however new ones will fail.
1311 */
1312static void evdev_mark_dead(struct evdev *evdev)
1313{
1314 mutex_lock(&evdev->mutex);
1315 evdev->exist = false;
1316 mutex_unlock(&evdev->mutex);
1317}
1318
1319static void evdev_cleanup(struct evdev *evdev)
1320{
1321 struct input_handle *handle = &evdev->handle;
1322
1323 evdev_mark_dead(evdev);
1324 evdev_hangup(evdev);
1325
1326 /* evdev is marked dead so no one else accesses evdev->open */
1327 if (evdev->open) {
1328 input_flush_device(handle, NULL);
1329 input_close_device(handle);
1330 }
1331}
1332
1333/*
1334 * Create new evdev device. Note that input core serializes calls
1335 * to connect and disconnect.
1336 */
1337static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1338 const struct input_device_id *id)
1339{
1340 struct evdev *evdev;
1341 int minor;
1342 int dev_no;
1343 int error;
1344
1345 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1346 if (minor < 0) {
1347 error = minor;
1348 pr_err("failed to reserve new minor: %d\n", error);
1349 return error;
1350 }
1351
1352 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1353 if (!evdev) {
1354 error = -ENOMEM;
1355 goto err_free_minor;
1356 }
1357
1358 INIT_LIST_HEAD(&evdev->client_list);
1359 spin_lock_init(&evdev->client_lock);
1360 mutex_init(&evdev->mutex);
1361 init_waitqueue_head(&evdev->wait);
1362 evdev->exist = true;
1363
1364 dev_no = minor;
1365 /* Normalize device number if it falls into legacy range */
1366 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1367 dev_no -= EVDEV_MINOR_BASE;
1368 dev_set_name(&evdev->dev, "event%d", dev_no);
1369
1370 evdev->handle.dev = input_get_device(dev);
1371 evdev->handle.name = dev_name(&evdev->dev);
1372 evdev->handle.handler = handler;
1373 evdev->handle.private = evdev;
1374
1375 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1376 evdev->dev.class = &input_class;
1377 evdev->dev.parent = &dev->dev;
1378 evdev->dev.release = evdev_free;
1379 device_initialize(&evdev->dev);
1380
1381 error = input_register_handle(&evdev->handle);
1382 if (error)
1383 goto err_free_evdev;
1384
1385 cdev_init(&evdev->cdev, &evdev_fops);
1386
1387 error = cdev_device_add(&evdev->cdev, &evdev->dev);
1388 if (error)
1389 goto err_cleanup_evdev;
1390
1391 return 0;
1392
1393 err_cleanup_evdev:
1394 evdev_cleanup(evdev);
1395 input_unregister_handle(&evdev->handle);
1396 err_free_evdev:
1397 put_device(&evdev->dev);
1398 err_free_minor:
1399 input_free_minor(minor);
1400 return error;
1401}
1402
1403static void evdev_disconnect(struct input_handle *handle)
1404{
1405 struct evdev *evdev = handle->private;
1406
1407 cdev_device_del(&evdev->cdev, &evdev->dev);
1408 evdev_cleanup(evdev);
1409 input_free_minor(MINOR(evdev->dev.devt));
1410 input_unregister_handle(handle);
1411 put_device(&evdev->dev);
1412}
1413
1414static const struct input_device_id evdev_ids[] = {
1415 { .driver_info = 1 }, /* Matches all devices */
1416 { }, /* Terminating zero entry */
1417};
1418
1419MODULE_DEVICE_TABLE(input, evdev_ids);
1420
1421static struct input_handler evdev_handler = {
1422 .event = evdev_event,
1423 .events = evdev_events,
1424 .connect = evdev_connect,
1425 .disconnect = evdev_disconnect,
1426 .legacy_minors = true,
1427 .minor = EVDEV_MINOR_BASE,
1428 .name = "evdev",
1429 .id_table = evdev_ids,
1430};
1431
1432static int __init evdev_init(void)
1433{
1434 return input_register_handler(&evdev_handler);
1435}
1436
1437static void __exit evdev_exit(void)
1438{
1439 input_unregister_handler(&evdev_handler);
1440}
1441
1442module_init(evdev_init);
1443module_exit(evdev_exit);
1444
1445MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1446MODULE_DESCRIPTION("Input driver event char devices");
1447MODULE_LICENSE("GPL");