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 unsigned int size = sizeof(struct evdev_client) +
507 bufsize * sizeof(struct input_event);
508 struct evdev_client *client;
509 int error;
510
511 client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
512 if (!client)
513 client = vzalloc(size);
514 if (!client)
515 return -ENOMEM;
516
517 client->bufsize = bufsize;
518 spin_lock_init(&client->buffer_lock);
519 client->evdev = evdev;
520 evdev_attach_client(evdev, client);
521
522 error = evdev_open_device(evdev);
523 if (error)
524 goto err_free_client;
525
526 file->private_data = client;
527 nonseekable_open(inode, file);
528
529 return 0;
530
531 err_free_client:
532 evdev_detach_client(evdev, client);
533 kvfree(client);
534 return error;
535}
536
537static ssize_t evdev_write(struct file *file, const char __user *buffer,
538 size_t count, loff_t *ppos)
539{
540 struct evdev_client *client = file->private_data;
541 struct evdev *evdev = client->evdev;
542 struct input_event event;
543 int retval = 0;
544
545 if (count != 0 && count < input_event_size())
546 return -EINVAL;
547
548 retval = mutex_lock_interruptible(&evdev->mutex);
549 if (retval)
550 return retval;
551
552 if (!evdev->exist || client->revoked) {
553 retval = -ENODEV;
554 goto out;
555 }
556
557 while (retval + input_event_size() <= count) {
558
559 if (input_event_from_user(buffer + retval, &event)) {
560 retval = -EFAULT;
561 goto out;
562 }
563 retval += input_event_size();
564
565 input_inject_event(&evdev->handle,
566 event.type, event.code, event.value);
567 cond_resched();
568 }
569
570 out:
571 mutex_unlock(&evdev->mutex);
572 return retval;
573}
574
575static int evdev_fetch_next_event(struct evdev_client *client,
576 struct input_event *event)
577{
578 int have_event;
579
580 spin_lock_irq(&client->buffer_lock);
581
582 have_event = client->packet_head != client->tail;
583 if (have_event) {
584 *event = client->buffer[client->tail++];
585 client->tail &= client->bufsize - 1;
586 }
587
588 spin_unlock_irq(&client->buffer_lock);
589
590 return have_event;
591}
592
593static ssize_t evdev_read(struct file *file, char __user *buffer,
594 size_t count, loff_t *ppos)
595{
596 struct evdev_client *client = file->private_data;
597 struct evdev *evdev = client->evdev;
598 struct input_event event;
599 size_t read = 0;
600 int error;
601
602 if (count != 0 && count < input_event_size())
603 return -EINVAL;
604
605 for (;;) {
606 if (!evdev->exist || client->revoked)
607 return -ENODEV;
608
609 if (client->packet_head == client->tail &&
610 (file->f_flags & O_NONBLOCK))
611 return -EAGAIN;
612
613 /*
614 * count == 0 is special - no IO is done but we check
615 * for error conditions (see above).
616 */
617 if (count == 0)
618 break;
619
620 while (read + input_event_size() <= count &&
621 evdev_fetch_next_event(client, &event)) {
622
623 if (input_event_to_user(buffer + read, &event))
624 return -EFAULT;
625
626 read += input_event_size();
627 }
628
629 if (read)
630 break;
631
632 if (!(file->f_flags & O_NONBLOCK)) {
633 error = wait_event_interruptible(evdev->wait,
634 client->packet_head != client->tail ||
635 !evdev->exist || client->revoked);
636 if (error)
637 return error;
638 }
639 }
640
641 return read;
642}
643
644/* No kernel lock - fine */
645static __poll_t evdev_poll(struct file *file, poll_table *wait)
646{
647 struct evdev_client *client = file->private_data;
648 struct evdev *evdev = client->evdev;
649 __poll_t mask;
650
651 poll_wait(file, &evdev->wait, wait);
652
653 if (evdev->exist && !client->revoked)
654 mask = EPOLLOUT | EPOLLWRNORM;
655 else
656 mask = EPOLLHUP | EPOLLERR;
657
658 if (client->packet_head != client->tail)
659 mask |= EPOLLIN | EPOLLRDNORM;
660
661 return mask;
662}
663
664#ifdef CONFIG_COMPAT
665
666#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
667#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
668
669#ifdef __BIG_ENDIAN
670static int bits_to_user(unsigned long *bits, unsigned int maxbit,
671 unsigned int maxlen, void __user *p, int compat)
672{
673 int len, i;
674
675 if (compat) {
676 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
677 if (len > maxlen)
678 len = maxlen;
679
680 for (i = 0; i < len / sizeof(compat_long_t); i++)
681 if (copy_to_user((compat_long_t __user *) p + i,
682 (compat_long_t *) bits +
683 i + 1 - ((i % 2) << 1),
684 sizeof(compat_long_t)))
685 return -EFAULT;
686 } else {
687 len = BITS_TO_LONGS(maxbit) * sizeof(long);
688 if (len > maxlen)
689 len = maxlen;
690
691 if (copy_to_user(p, bits, len))
692 return -EFAULT;
693 }
694
695 return len;
696}
697
698static int bits_from_user(unsigned long *bits, unsigned int maxbit,
699 unsigned int maxlen, const void __user *p, int compat)
700{
701 int len, i;
702
703 if (compat) {
704 if (maxlen % sizeof(compat_long_t))
705 return -EINVAL;
706
707 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
708 if (len > maxlen)
709 len = maxlen;
710
711 for (i = 0; i < len / sizeof(compat_long_t); i++)
712 if (copy_from_user((compat_long_t *) bits +
713 i + 1 - ((i % 2) << 1),
714 (compat_long_t __user *) p + i,
715 sizeof(compat_long_t)))
716 return -EFAULT;
717 if (i % 2)
718 *((compat_long_t *) bits + i - 1) = 0;
719
720 } else {
721 if (maxlen % sizeof(long))
722 return -EINVAL;
723
724 len = BITS_TO_LONGS(maxbit) * sizeof(long);
725 if (len > maxlen)
726 len = maxlen;
727
728 if (copy_from_user(bits, p, len))
729 return -EFAULT;
730 }
731
732 return len;
733}
734
735#else
736
737static int bits_to_user(unsigned long *bits, unsigned int maxbit,
738 unsigned int maxlen, void __user *p, int compat)
739{
740 int len = compat ?
741 BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
742 BITS_TO_LONGS(maxbit) * sizeof(long);
743
744 if (len > maxlen)
745 len = maxlen;
746
747 return copy_to_user(p, bits, len) ? -EFAULT : len;
748}
749
750static int bits_from_user(unsigned long *bits, unsigned int maxbit,
751 unsigned int maxlen, const void __user *p, int compat)
752{
753 size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
754 int len;
755
756 if (maxlen % chunk_size)
757 return -EINVAL;
758
759 len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
760 len *= chunk_size;
761 if (len > maxlen)
762 len = maxlen;
763
764 return copy_from_user(bits, p, len) ? -EFAULT : len;
765}
766
767#endif /* __BIG_ENDIAN */
768
769#else
770
771static int bits_to_user(unsigned long *bits, unsigned int maxbit,
772 unsigned int maxlen, void __user *p, int compat)
773{
774 int len = BITS_TO_LONGS(maxbit) * sizeof(long);
775
776 if (len > maxlen)
777 len = maxlen;
778
779 return copy_to_user(p, bits, len) ? -EFAULT : len;
780}
781
782static int bits_from_user(unsigned long *bits, unsigned int maxbit,
783 unsigned int maxlen, const void __user *p, int compat)
784{
785 int len;
786
787 if (maxlen % sizeof(long))
788 return -EINVAL;
789
790 len = BITS_TO_LONGS(maxbit) * sizeof(long);
791 if (len > maxlen)
792 len = maxlen;
793
794 return copy_from_user(bits, p, len) ? -EFAULT : len;
795}
796
797#endif /* CONFIG_COMPAT */
798
799static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
800{
801 int len;
802
803 if (!str)
804 return -ENOENT;
805
806 len = strlen(str) + 1;
807 if (len > maxlen)
808 len = maxlen;
809
810 return copy_to_user(p, str, len) ? -EFAULT : len;
811}
812
813static int handle_eviocgbit(struct input_dev *dev,
814 unsigned int type, unsigned int size,
815 void __user *p, int compat_mode)
816{
817 unsigned long *bits;
818 int len;
819
820 switch (type) {
821
822 case 0: bits = dev->evbit; len = EV_MAX; break;
823 case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
824 case EV_REL: bits = dev->relbit; len = REL_MAX; break;
825 case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
826 case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
827 case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
828 case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
829 case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
830 case EV_SW: bits = dev->swbit; len = SW_MAX; break;
831 default: return -EINVAL;
832 }
833
834 return bits_to_user(bits, len, size, p, compat_mode);
835}
836
837static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
838{
839 struct input_keymap_entry ke = {
840 .len = sizeof(unsigned int),
841 .flags = 0,
842 };
843 int __user *ip = (int __user *)p;
844 int error;
845
846 /* legacy case */
847 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
848 return -EFAULT;
849
850 error = input_get_keycode(dev, &ke);
851 if (error)
852 return error;
853
854 if (put_user(ke.keycode, ip + 1))
855 return -EFAULT;
856
857 return 0;
858}
859
860static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
861{
862 struct input_keymap_entry ke;
863 int error;
864
865 if (copy_from_user(&ke, p, sizeof(ke)))
866 return -EFAULT;
867
868 error = input_get_keycode(dev, &ke);
869 if (error)
870 return error;
871
872 if (copy_to_user(p, &ke, sizeof(ke)))
873 return -EFAULT;
874
875 return 0;
876}
877
878static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
879{
880 struct input_keymap_entry ke = {
881 .len = sizeof(unsigned int),
882 .flags = 0,
883 };
884 int __user *ip = (int __user *)p;
885
886 if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
887 return -EFAULT;
888
889 if (get_user(ke.keycode, ip + 1))
890 return -EFAULT;
891
892 return input_set_keycode(dev, &ke);
893}
894
895static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
896{
897 struct input_keymap_entry ke;
898
899 if (copy_from_user(&ke, p, sizeof(ke)))
900 return -EFAULT;
901
902 if (ke.len > sizeof(ke.scancode))
903 return -EINVAL;
904
905 return input_set_keycode(dev, &ke);
906}
907
908/*
909 * If we transfer state to the user, we should flush all pending events
910 * of the same type from the client's queue. Otherwise, they might end up
911 * with duplicate events, which can screw up client's state tracking.
912 * If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
913 * event so user-space will notice missing events.
914 *
915 * LOCKING:
916 * We need to take event_lock before buffer_lock to avoid dead-locks. But we
917 * need the even_lock only to guarantee consistent state. We can safely release
918 * it while flushing the queue. This allows input-core to handle filters while
919 * we flush the queue.
920 */
921static int evdev_handle_get_val(struct evdev_client *client,
922 struct input_dev *dev, unsigned int type,
923 unsigned long *bits, unsigned int maxbit,
924 unsigned int maxlen, void __user *p,
925 int compat)
926{
927 int ret;
928 unsigned long *mem;
929
930 mem = bitmap_alloc(maxbit, GFP_KERNEL);
931 if (!mem)
932 return -ENOMEM;
933
934 spin_lock_irq(&dev->event_lock);
935 spin_lock(&client->buffer_lock);
936
937 bitmap_copy(mem, bits, maxbit);
938
939 spin_unlock(&dev->event_lock);
940
941 __evdev_flush_queue(client, type);
942
943 spin_unlock_irq(&client->buffer_lock);
944
945 ret = bits_to_user(mem, maxbit, maxlen, p, compat);
946 if (ret < 0)
947 evdev_queue_syn_dropped(client);
948
949 bitmap_free(mem);
950
951 return ret;
952}
953
954static int evdev_handle_mt_request(struct input_dev *dev,
955 unsigned int size,
956 int __user *ip)
957{
958 const struct input_mt *mt = dev->mt;
959 unsigned int code;
960 int max_slots;
961 int i;
962
963 if (get_user(code, &ip[0]))
964 return -EFAULT;
965 if (!mt || !input_is_mt_value(code))
966 return -EINVAL;
967
968 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
969 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
970 int value = input_mt_get_value(&mt->slots[i], code);
971 if (put_user(value, &ip[1 + i]))
972 return -EFAULT;
973 }
974
975 return 0;
976}
977
978static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
979 struct file *file)
980{
981 client->revoked = true;
982 evdev_ungrab(evdev, client);
983 input_flush_device(&evdev->handle, file);
984 wake_up_interruptible(&evdev->wait);
985
986 return 0;
987}
988
989/* must be called with evdev-mutex held */
990static int evdev_set_mask(struct evdev_client *client,
991 unsigned int type,
992 const void __user *codes,
993 u32 codes_size,
994 int compat)
995{
996 unsigned long flags, *mask, *oldmask;
997 size_t cnt;
998 int error;
999
1000 /* we allow unknown types and 'codes_size > size' for forward-compat */
1001 cnt = evdev_get_mask_cnt(type);
1002 if (!cnt)
1003 return 0;
1004
1005 mask = bitmap_zalloc(cnt, GFP_KERNEL);
1006 if (!mask)
1007 return -ENOMEM;
1008
1009 error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1010 if (error < 0) {
1011 bitmap_free(mask);
1012 return error;
1013 }
1014
1015 spin_lock_irqsave(&client->buffer_lock, flags);
1016 oldmask = client->evmasks[type];
1017 client->evmasks[type] = mask;
1018 spin_unlock_irqrestore(&client->buffer_lock, flags);
1019
1020 bitmap_free(oldmask);
1021
1022 return 0;
1023}
1024
1025/* must be called with evdev-mutex held */
1026static int evdev_get_mask(struct evdev_client *client,
1027 unsigned int type,
1028 void __user *codes,
1029 u32 codes_size,
1030 int compat)
1031{
1032 unsigned long *mask;
1033 size_t cnt, size, xfer_size;
1034 int i;
1035 int error;
1036
1037 /* we allow unknown types and 'codes_size > size' for forward-compat */
1038 cnt = evdev_get_mask_cnt(type);
1039 size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1040 xfer_size = min_t(size_t, codes_size, size);
1041
1042 if (cnt > 0) {
1043 mask = client->evmasks[type];
1044 if (mask) {
1045 error = bits_to_user(mask, cnt - 1,
1046 xfer_size, codes, compat);
1047 if (error < 0)
1048 return error;
1049 } else {
1050 /* fake mask with all bits set */
1051 for (i = 0; i < xfer_size; i++)
1052 if (put_user(0xffU, (u8 __user *)codes + i))
1053 return -EFAULT;
1054 }
1055 }
1056
1057 if (xfer_size < codes_size)
1058 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1059 return -EFAULT;
1060
1061 return 0;
1062}
1063
1064static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1065 void __user *p, int compat_mode)
1066{
1067 struct evdev_client *client = file->private_data;
1068 struct evdev *evdev = client->evdev;
1069 struct input_dev *dev = evdev->handle.dev;
1070 struct input_absinfo abs;
1071 struct input_mask mask;
1072 struct ff_effect effect;
1073 int __user *ip = (int __user *)p;
1074 unsigned int i, t, u, v;
1075 unsigned int size;
1076 int error;
1077
1078 /* First we check for fixed-length commands */
1079 switch (cmd) {
1080
1081 case EVIOCGVERSION:
1082 return put_user(EV_VERSION, ip);
1083
1084 case EVIOCGID:
1085 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1086 return -EFAULT;
1087 return 0;
1088
1089 case EVIOCGREP:
1090 if (!test_bit(EV_REP, dev->evbit))
1091 return -ENOSYS;
1092 if (put_user(dev->rep[REP_DELAY], ip))
1093 return -EFAULT;
1094 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1095 return -EFAULT;
1096 return 0;
1097
1098 case EVIOCSREP:
1099 if (!test_bit(EV_REP, dev->evbit))
1100 return -ENOSYS;
1101 if (get_user(u, ip))
1102 return -EFAULT;
1103 if (get_user(v, ip + 1))
1104 return -EFAULT;
1105
1106 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1107 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1108
1109 return 0;
1110
1111 case EVIOCRMFF:
1112 return input_ff_erase(dev, (int)(unsigned long) p, file);
1113
1114 case EVIOCGEFFECTS:
1115 i = test_bit(EV_FF, dev->evbit) ?
1116 dev->ff->max_effects : 0;
1117 if (put_user(i, ip))
1118 return -EFAULT;
1119 return 0;
1120
1121 case EVIOCGRAB:
1122 if (p)
1123 return evdev_grab(evdev, client);
1124 else
1125 return evdev_ungrab(evdev, client);
1126
1127 case EVIOCREVOKE:
1128 if (p)
1129 return -EINVAL;
1130 else
1131 return evdev_revoke(evdev, client, file);
1132
1133 case EVIOCGMASK: {
1134 void __user *codes_ptr;
1135
1136 if (copy_from_user(&mask, p, sizeof(mask)))
1137 return -EFAULT;
1138
1139 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1140 return evdev_get_mask(client,
1141 mask.type, codes_ptr, mask.codes_size,
1142 compat_mode);
1143 }
1144
1145 case EVIOCSMASK: {
1146 const void __user *codes_ptr;
1147
1148 if (copy_from_user(&mask, p, sizeof(mask)))
1149 return -EFAULT;
1150
1151 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1152 return evdev_set_mask(client,
1153 mask.type, codes_ptr, mask.codes_size,
1154 compat_mode);
1155 }
1156
1157 case EVIOCSCLOCKID:
1158 if (copy_from_user(&i, p, sizeof(unsigned int)))
1159 return -EFAULT;
1160
1161 return evdev_set_clk_type(client, i);
1162
1163 case EVIOCGKEYCODE:
1164 return evdev_handle_get_keycode(dev, p);
1165
1166 case EVIOCSKEYCODE:
1167 return evdev_handle_set_keycode(dev, p);
1168
1169 case EVIOCGKEYCODE_V2:
1170 return evdev_handle_get_keycode_v2(dev, p);
1171
1172 case EVIOCSKEYCODE_V2:
1173 return evdev_handle_set_keycode_v2(dev, p);
1174 }
1175
1176 size = _IOC_SIZE(cmd);
1177
1178 /* Now check variable-length commands */
1179#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1180 switch (EVIOC_MASK_SIZE(cmd)) {
1181
1182 case EVIOCGPROP(0):
1183 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1184 size, p, compat_mode);
1185
1186 case EVIOCGMTSLOTS(0):
1187 return evdev_handle_mt_request(dev, size, ip);
1188
1189 case EVIOCGKEY(0):
1190 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1191 KEY_MAX, size, p, compat_mode);
1192
1193 case EVIOCGLED(0):
1194 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1195 LED_MAX, size, p, compat_mode);
1196
1197 case EVIOCGSND(0):
1198 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1199 SND_MAX, size, p, compat_mode);
1200
1201 case EVIOCGSW(0):
1202 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1203 SW_MAX, size, p, compat_mode);
1204
1205 case EVIOCGNAME(0):
1206 return str_to_user(dev->name, size, p);
1207
1208 case EVIOCGPHYS(0):
1209 return str_to_user(dev->phys, size, p);
1210
1211 case EVIOCGUNIQ(0):
1212 return str_to_user(dev->uniq, size, p);
1213
1214 case EVIOC_MASK_SIZE(EVIOCSFF):
1215 if (input_ff_effect_from_user(p, size, &effect))
1216 return -EFAULT;
1217
1218 error = input_ff_upload(dev, &effect, file);
1219 if (error)
1220 return error;
1221
1222 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1223 return -EFAULT;
1224
1225 return 0;
1226 }
1227
1228 /* Multi-number variable-length handlers */
1229 if (_IOC_TYPE(cmd) != 'E')
1230 return -EINVAL;
1231
1232 if (_IOC_DIR(cmd) == _IOC_READ) {
1233
1234 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1235 return handle_eviocgbit(dev,
1236 _IOC_NR(cmd) & EV_MAX, size,
1237 p, compat_mode);
1238
1239 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1240
1241 if (!dev->absinfo)
1242 return -EINVAL;
1243
1244 t = _IOC_NR(cmd) & ABS_MAX;
1245 abs = dev->absinfo[t];
1246
1247 if (copy_to_user(p, &abs, min_t(size_t,
1248 size, sizeof(struct input_absinfo))))
1249 return -EFAULT;
1250
1251 return 0;
1252 }
1253 }
1254
1255 if (_IOC_DIR(cmd) == _IOC_WRITE) {
1256
1257 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1258
1259 if (!dev->absinfo)
1260 return -EINVAL;
1261
1262 t = _IOC_NR(cmd) & ABS_MAX;
1263
1264 if (copy_from_user(&abs, p, min_t(size_t,
1265 size, sizeof(struct input_absinfo))))
1266 return -EFAULT;
1267
1268 if (size < sizeof(struct input_absinfo))
1269 abs.resolution = 0;
1270
1271 /* We can't change number of reserved MT slots */
1272 if (t == ABS_MT_SLOT)
1273 return -EINVAL;
1274
1275 /*
1276 * Take event lock to ensure that we are not
1277 * changing device parameters in the middle
1278 * of event.
1279 */
1280 spin_lock_irq(&dev->event_lock);
1281 dev->absinfo[t] = abs;
1282 spin_unlock_irq(&dev->event_lock);
1283
1284 return 0;
1285 }
1286 }
1287
1288 return -EINVAL;
1289}
1290
1291static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1292 void __user *p, int compat_mode)
1293{
1294 struct evdev_client *client = file->private_data;
1295 struct evdev *evdev = client->evdev;
1296 int retval;
1297
1298 retval = mutex_lock_interruptible(&evdev->mutex);
1299 if (retval)
1300 return retval;
1301
1302 if (!evdev->exist || client->revoked) {
1303 retval = -ENODEV;
1304 goto out;
1305 }
1306
1307 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1308
1309 out:
1310 mutex_unlock(&evdev->mutex);
1311 return retval;
1312}
1313
1314static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1315{
1316 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1317}
1318
1319#ifdef CONFIG_COMPAT
1320static long evdev_ioctl_compat(struct file *file,
1321 unsigned int cmd, unsigned long arg)
1322{
1323 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1324}
1325#endif
1326
1327static const struct file_operations evdev_fops = {
1328 .owner = THIS_MODULE,
1329 .read = evdev_read,
1330 .write = evdev_write,
1331 .poll = evdev_poll,
1332 .open = evdev_open,
1333 .release = evdev_release,
1334 .unlocked_ioctl = evdev_ioctl,
1335#ifdef CONFIG_COMPAT
1336 .compat_ioctl = evdev_ioctl_compat,
1337#endif
1338 .fasync = evdev_fasync,
1339 .flush = evdev_flush,
1340 .llseek = no_llseek,
1341};
1342
1343/*
1344 * Mark device non-existent. This disables writes, ioctls and
1345 * prevents new users from opening the device. Already posted
1346 * blocking reads will stay, however new ones will fail.
1347 */
1348static void evdev_mark_dead(struct evdev *evdev)
1349{
1350 mutex_lock(&evdev->mutex);
1351 evdev->exist = false;
1352 mutex_unlock(&evdev->mutex);
1353}
1354
1355static void evdev_cleanup(struct evdev *evdev)
1356{
1357 struct input_handle *handle = &evdev->handle;
1358
1359 evdev_mark_dead(evdev);
1360 evdev_hangup(evdev);
1361
1362 /* evdev is marked dead so no one else accesses evdev->open */
1363 if (evdev->open) {
1364 input_flush_device(handle, NULL);
1365 input_close_device(handle);
1366 }
1367}
1368
1369/*
1370 * Create new evdev device. Note that input core serializes calls
1371 * to connect and disconnect.
1372 */
1373static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1374 const struct input_device_id *id)
1375{
1376 struct evdev *evdev;
1377 int minor;
1378 int dev_no;
1379 int error;
1380
1381 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1382 if (minor < 0) {
1383 error = minor;
1384 pr_err("failed to reserve new minor: %d\n", error);
1385 return error;
1386 }
1387
1388 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1389 if (!evdev) {
1390 error = -ENOMEM;
1391 goto err_free_minor;
1392 }
1393
1394 INIT_LIST_HEAD(&evdev->client_list);
1395 spin_lock_init(&evdev->client_lock);
1396 mutex_init(&evdev->mutex);
1397 init_waitqueue_head(&evdev->wait);
1398 evdev->exist = true;
1399
1400 dev_no = minor;
1401 /* Normalize device number if it falls into legacy range */
1402 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1403 dev_no -= EVDEV_MINOR_BASE;
1404 dev_set_name(&evdev->dev, "event%d", dev_no);
1405
1406 evdev->handle.dev = input_get_device(dev);
1407 evdev->handle.name = dev_name(&evdev->dev);
1408 evdev->handle.handler = handler;
1409 evdev->handle.private = evdev;
1410
1411 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1412 evdev->dev.class = &input_class;
1413 evdev->dev.parent = &dev->dev;
1414 evdev->dev.release = evdev_free;
1415 device_initialize(&evdev->dev);
1416
1417 error = input_register_handle(&evdev->handle);
1418 if (error)
1419 goto err_free_evdev;
1420
1421 cdev_init(&evdev->cdev, &evdev_fops);
1422
1423 error = cdev_device_add(&evdev->cdev, &evdev->dev);
1424 if (error)
1425 goto err_cleanup_evdev;
1426
1427 return 0;
1428
1429 err_cleanup_evdev:
1430 evdev_cleanup(evdev);
1431 input_unregister_handle(&evdev->handle);
1432 err_free_evdev:
1433 put_device(&evdev->dev);
1434 err_free_minor:
1435 input_free_minor(minor);
1436 return error;
1437}
1438
1439static void evdev_disconnect(struct input_handle *handle)
1440{
1441 struct evdev *evdev = handle->private;
1442
1443 cdev_device_del(&evdev->cdev, &evdev->dev);
1444 evdev_cleanup(evdev);
1445 input_free_minor(MINOR(evdev->dev.devt));
1446 input_unregister_handle(handle);
1447 put_device(&evdev->dev);
1448}
1449
1450static const struct input_device_id evdev_ids[] = {
1451 { .driver_info = 1 }, /* Matches all devices */
1452 { }, /* Terminating zero entry */
1453};
1454
1455MODULE_DEVICE_TABLE(input, evdev_ids);
1456
1457static struct input_handler evdev_handler = {
1458 .event = evdev_event,
1459 .events = evdev_events,
1460 .connect = evdev_connect,
1461 .disconnect = evdev_disconnect,
1462 .legacy_minors = true,
1463 .minor = EVDEV_MINOR_BASE,
1464 .name = "evdev",
1465 .id_table = evdev_ids,
1466};
1467
1468static int __init evdev_init(void)
1469{
1470 return input_register_handler(&evdev_handler);
1471}
1472
1473static void __exit evdev_exit(void)
1474{
1475 input_unregister_handler(&evdev_handler);
1476}
1477
1478module_init(evdev_init);
1479module_exit(evdev_exit);
1480
1481MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1482MODULE_DESCRIPTION("Input driver event char devices");
1483MODULE_LICENSE("GPL");
1484