projects/linux·blob v5.2-rc2 · refs

1482 lines · 33.2 KiB

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