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