?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / drivers / input / evdev.c
blobc81c79d01d93078fb2a4357e6f0c51aea6a2b12b
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
31 enum evdev_clock_type {
32 EV_CLK_REAL = 0,
33 EV_CLK_MONO,
34 EV_CLK_BOOT,
35 EV_CLK_MAX
36 };
37
38 struct 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
51 struct 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
66 static 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 */
85 static 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 */
111 static 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
153 static 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
182 static 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
191 static 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
231 static 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
261 static 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 */
308 static 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 */
336 static 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
344 static 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
351 static 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
365 static 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 */
377 static 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
393 static 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
408 static 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
416 static 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
425 static 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
445 static 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 */
459 static 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
471 static 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 kfree(client->evmasks[i]);
485
486 kvfree(client);
487
488 evdev_close_device(evdev);
489
490 return 0;
491 }
492
493 static 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
502 static 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
537 static 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 }
568
569 out:
570 mutex_unlock(&evdev->mutex);
571 return retval;
572 }
573
574 static 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
592 static 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 */
644 static __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
669 static 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
697 static 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
736 static 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
749 static 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
770 static 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
781 static 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
798 static 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
812 static 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
836 static 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
859 static 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
877 static 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
894 static 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 */
920 static 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 size_t len;
929
930 len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
931 mem = kmalloc(len, GFP_KERNEL);
932 if (!mem)
933 return -ENOMEM;
934
935 spin_lock_irq(&dev->event_lock);
936 spin_lock(&client->buffer_lock);
937
938 memcpy(mem, bits, len);
939
940 spin_unlock(&dev->event_lock);
941
942 __evdev_flush_queue(client, type);
943
944 spin_unlock_irq(&client->buffer_lock);
945
946 ret = bits_to_user(mem, maxbit, maxlen, p, compat);
947 if (ret < 0)
948 evdev_queue_syn_dropped(client);
949
950 kfree(mem);
951
952 return ret;
953 }
954
955 static int evdev_handle_mt_request(struct input_dev *dev,
956 unsigned int size,
957 int __user *ip)
958 {
959 const struct input_mt *mt = dev->mt;
960 unsigned int code;
961 int max_slots;
962 int i;
963
964 if (get_user(code, &ip[0]))
965 return -EFAULT;
966 if (!mt || !input_is_mt_value(code))
967 return -EINVAL;
968
969 max_slots = (size - sizeof(__u32)) / sizeof(__s32);
970 for (i = 0; i < mt->num_slots && i < max_slots; i++) {
971 int value = input_mt_get_value(&mt->slots[i], code);
972 if (put_user(value, &ip[1 + i]))
973 return -EFAULT;
974 }
975
976 return 0;
977 }
978
979 static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
980 struct file *file)
981 {
982 client->revoked = true;
983 evdev_ungrab(evdev, client);
984 input_flush_device(&evdev->handle, file);
985 wake_up_interruptible(&evdev->wait);
986
987 return 0;
988 }
989
990 /* must be called with evdev-mutex held */
991 static int evdev_set_mask(struct evdev_client *client,
992 unsigned int type,
993 const void __user *codes,
994 u32 codes_size,
995 int compat)
996 {
997 unsigned long flags, *mask, *oldmask;
998 size_t cnt;
999 int error;
1000
1001 /* we allow unknown types and 'codes_size > size' for forward-compat */
1002 cnt = evdev_get_mask_cnt(type);
1003 if (!cnt)
1004 return 0;
1005
1006 mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL);
1007 if (!mask)
1008 return -ENOMEM;
1009
1010 error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
1011 if (error < 0) {
1012 kfree(mask);
1013 return error;
1014 }
1015
1016 spin_lock_irqsave(&client->buffer_lock, flags);
1017 oldmask = client->evmasks[type];
1018 client->evmasks[type] = mask;
1019 spin_unlock_irqrestore(&client->buffer_lock, flags);
1020
1021 kfree(oldmask);
1022
1023 return 0;
1024 }
1025
1026 /* must be called with evdev-mutex held */
1027 static int evdev_get_mask(struct evdev_client *client,
1028 unsigned int type,
1029 void __user *codes,
1030 u32 codes_size,
1031 int compat)
1032 {
1033 unsigned long *mask;
1034 size_t cnt, size, xfer_size;
1035 int i;
1036 int error;
1037
1038 /* we allow unknown types and 'codes_size > size' for forward-compat */
1039 cnt = evdev_get_mask_cnt(type);
1040 size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
1041 xfer_size = min_t(size_t, codes_size, size);
1042
1043 if (cnt > 0) {
1044 mask = client->evmasks[type];
1045 if (mask) {
1046 error = bits_to_user(mask, cnt - 1,
1047 xfer_size, codes, compat);
1048 if (error < 0)
1049 return error;
1050 } else {
1051 /* fake mask with all bits set */
1052 for (i = 0; i < xfer_size; i++)
1053 if (put_user(0xffU, (u8 __user *)codes + i))
1054 return -EFAULT;
1055 }
1056 }
1057
1058 if (xfer_size < codes_size)
1059 if (clear_user(codes + xfer_size, codes_size - xfer_size))
1060 return -EFAULT;
1061
1062 return 0;
1063 }
1064
1065 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
1066 void __user *p, int compat_mode)
1067 {
1068 struct evdev_client *client = file->private_data;
1069 struct evdev *evdev = client->evdev;
1070 struct input_dev *dev = evdev->handle.dev;
1071 struct input_absinfo abs;
1072 struct input_mask mask;
1073 struct ff_effect effect;
1074 int __user *ip = (int __user *)p;
1075 unsigned int i, t, u, v;
1076 unsigned int size;
1077 int error;
1078
1079 /* First we check for fixed-length commands */
1080 switch (cmd) {
1081
1082 case EVIOCGVERSION:
1083 return put_user(EV_VERSION, ip);
1084
1085 case EVIOCGID:
1086 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
1087 return -EFAULT;
1088 return 0;
1089
1090 case EVIOCGREP:
1091 if (!test_bit(EV_REP, dev->evbit))
1092 return -ENOSYS;
1093 if (put_user(dev->rep[REP_DELAY], ip))
1094 return -EFAULT;
1095 if (put_user(dev->rep[REP_PERIOD], ip + 1))
1096 return -EFAULT;
1097 return 0;
1098
1099 case EVIOCSREP:
1100 if (!test_bit(EV_REP, dev->evbit))
1101 return -ENOSYS;
1102 if (get_user(u, ip))
1103 return -EFAULT;
1104 if (get_user(v, ip + 1))
1105 return -EFAULT;
1106
1107 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
1108 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
1109
1110 return 0;
1111
1112 case EVIOCRMFF:
1113 return input_ff_erase(dev, (int)(unsigned long) p, file);
1114
1115 case EVIOCGEFFECTS:
1116 i = test_bit(EV_FF, dev->evbit) ?
1117 dev->ff->max_effects : 0;
1118 if (put_user(i, ip))
1119 return -EFAULT;
1120 return 0;
1121
1122 case EVIOCGRAB:
1123 if (p)
1124 return evdev_grab(evdev, client);
1125 else
1126 return evdev_ungrab(evdev, client);
1127
1128 case EVIOCREVOKE:
1129 if (p)
1130 return -EINVAL;
1131 else
1132 return evdev_revoke(evdev, client, file);
1133
1134 case EVIOCGMASK: {
1135 void __user *codes_ptr;
1136
1137 if (copy_from_user(&mask, p, sizeof(mask)))
1138 return -EFAULT;
1139
1140 codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
1141 return evdev_get_mask(client,
1142 mask.type, codes_ptr, mask.codes_size,
1143 compat_mode);
1144 }
1145
1146 case EVIOCSMASK: {
1147 const void __user *codes_ptr;
1148
1149 if (copy_from_user(&mask, p, sizeof(mask)))
1150 return -EFAULT;
1151
1152 codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
1153 return evdev_set_mask(client,
1154 mask.type, codes_ptr, mask.codes_size,
1155 compat_mode);
1156 }
1157
1158 case EVIOCSCLOCKID:
1159 if (copy_from_user(&i, p, sizeof(unsigned int)))
1160 return -EFAULT;
1161
1162 return evdev_set_clk_type(client, i);
1163
1164 case EVIOCGKEYCODE:
1165 return evdev_handle_get_keycode(dev, p);
1166
1167 case EVIOCSKEYCODE:
1168 return evdev_handle_set_keycode(dev, p);
1169
1170 case EVIOCGKEYCODE_V2:
1171 return evdev_handle_get_keycode_v2(dev, p);
1172
1173 case EVIOCSKEYCODE_V2:
1174 return evdev_handle_set_keycode_v2(dev, p);
1175 }
1176
1177 size = _IOC_SIZE(cmd);
1178
1179 /* Now check variable-length commands */
1180 #define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
1181 switch (EVIOC_MASK_SIZE(cmd)) {
1182
1183 case EVIOCGPROP(0):
1184 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
1185 size, p, compat_mode);
1186
1187 case EVIOCGMTSLOTS(0):
1188 return evdev_handle_mt_request(dev, size, ip);
1189
1190 case EVIOCGKEY(0):
1191 return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
1192 KEY_MAX, size, p, compat_mode);
1193
1194 case EVIOCGLED(0):
1195 return evdev_handle_get_val(client, dev, EV_LED, dev->led,
1196 LED_MAX, size, p, compat_mode);
1197
1198 case EVIOCGSND(0):
1199 return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
1200 SND_MAX, size, p, compat_mode);
1201
1202 case EVIOCGSW(0):
1203 return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
1204 SW_MAX, size, p, compat_mode);
1205
1206 case EVIOCGNAME(0):
1207 return str_to_user(dev->name, size, p);
1208
1209 case EVIOCGPHYS(0):
1210 return str_to_user(dev->phys, size, p);
1211
1212 case EVIOCGUNIQ(0):
1213 return str_to_user(dev->uniq, size, p);
1214
1215 case EVIOC_MASK_SIZE(EVIOCSFF):
1216 if (input_ff_effect_from_user(p, size, &effect))
1217 return -EFAULT;
1218
1219 error = input_ff_upload(dev, &effect, file);
1220 if (error)
1221 return error;
1222
1223 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
1224 return -EFAULT;
1225
1226 return 0;
1227 }
1228
1229 /* Multi-number variable-length handlers */
1230 if (_IOC_TYPE(cmd) != 'E')
1231 return -EINVAL;
1232
1233 if (_IOC_DIR(cmd) == _IOC_READ) {
1234
1235 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
1236 return handle_eviocgbit(dev,
1237 _IOC_NR(cmd) & EV_MAX, size,
1238 p, compat_mode);
1239
1240 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
1241
1242 if (!dev->absinfo)
1243 return -EINVAL;
1244
1245 t = _IOC_NR(cmd) & ABS_MAX;
1246 abs = dev->absinfo[t];
1247
1248 if (copy_to_user(p, &abs, min_t(size_t,
1249 size, sizeof(struct input_absinfo))))
1250 return -EFAULT;
1251
1252 return 0;
1253 }
1254 }
1255
1256 if (_IOC_DIR(cmd) == _IOC_WRITE) {
1257
1258 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
1259
1260 if (!dev->absinfo)
1261 return -EINVAL;
1262
1263 t = _IOC_NR(cmd) & ABS_MAX;
1264
1265 if (copy_from_user(&abs, p, min_t(size_t,
1266 size, sizeof(struct input_absinfo))))
1267 return -EFAULT;
1268
1269 if (size < sizeof(struct input_absinfo))
1270 abs.resolution = 0;
1271
1272 /* We can't change number of reserved MT slots */
1273 if (t == ABS_MT_SLOT)
1274 return -EINVAL;
1275
1276 /*
1277 * Take event lock to ensure that we are not
1278 * changing device parameters in the middle
1279 * of event.
1280 */
1281 spin_lock_irq(&dev->event_lock);
1282 dev->absinfo[t] = abs;
1283 spin_unlock_irq(&dev->event_lock);
1284
1285 return 0;
1286 }
1287 }
1288
1289 return -EINVAL;
1290 }
1291
1292 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
1293 void __user *p, int compat_mode)
1294 {
1295 struct evdev_client *client = file->private_data;
1296 struct evdev *evdev = client->evdev;
1297 int retval;
1298
1299 retval = mutex_lock_interruptible(&evdev->mutex);
1300 if (retval)
1301 return retval;
1302
1303 if (!evdev->exist || client->revoked) {
1304 retval = -ENODEV;
1305 goto out;
1306 }
1307
1308 retval = evdev_do_ioctl(file, cmd, p, compat_mode);
1309
1310 out:
1311 mutex_unlock(&evdev->mutex);
1312 return retval;
1313 }
1314
1315 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1316 {
1317 return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
1318 }
1319
1320 #ifdef CONFIG_COMPAT
1321 static long evdev_ioctl_compat(struct file *file,
1322 unsigned int cmd, unsigned long arg)
1323 {
1324 return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
1325 }
1326 #endif
1327
1328 static const struct file_operations evdev_fops = {
1329 .owner = THIS_MODULE,
1330 .read = evdev_read,
1331 .write = evdev_write,
1332 .poll = evdev_poll,
1333 .open = evdev_open,
1334 .release = evdev_release,
1335 .unlocked_ioctl = evdev_ioctl,
1336 #ifdef CONFIG_COMPAT
1337 .compat_ioctl = evdev_ioctl_compat,
1338 #endif
1339 .fasync = evdev_fasync,
1340 .flush = evdev_flush,
1341 .llseek = no_llseek,
1342 };
1343
1344 /*
1345 * Mark device non-existent. This disables writes, ioctls and
1346 * prevents new users from opening the device. Already posted
1347 * blocking reads will stay, however new ones will fail.
1348 */
1349 static void evdev_mark_dead(struct evdev *evdev)
1350 {
1351 mutex_lock(&evdev->mutex);
1352 evdev->exist = false;
1353 mutex_unlock(&evdev->mutex);
1354 }
1355
1356 static void evdev_cleanup(struct evdev *evdev)
1357 {
1358 struct input_handle *handle = &evdev->handle;
1359
1360 evdev_mark_dead(evdev);
1361 evdev_hangup(evdev);
1362
1363 /* evdev is marked dead so no one else accesses evdev->open */
1364 if (evdev->open) {
1365 input_flush_device(handle, NULL);
1366 input_close_device(handle);
1367 }
1368 }
1369
1370 /*
1371 * Create new evdev device. Note that input core serializes calls
1372 * to connect and disconnect.
1373 */
1374 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
1375 const struct input_device_id *id)
1376 {
1377 struct evdev *evdev;
1378 int minor;
1379 int dev_no;
1380 int error;
1381
1382 minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
1383 if (minor < 0) {
1384 error = minor;
1385 pr_err("failed to reserve new minor: %d\n", error);
1386 return error;
1387 }
1388
1389 evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
1390 if (!evdev) {
1391 error = -ENOMEM;
1392 goto err_free_minor;
1393 }
1394
1395 INIT_LIST_HEAD(&evdev->client_list);
1396 spin_lock_init(&evdev->client_lock);
1397 mutex_init(&evdev->mutex);
1398 init_waitqueue_head(&evdev->wait);
1399 evdev->exist = true;
1400
1401 dev_no = minor;
1402 /* Normalize device number if it falls into legacy range */
1403 if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
1404 dev_no -= EVDEV_MINOR_BASE;
1405 dev_set_name(&evdev->dev, "event%d", dev_no);
1406
1407 evdev->handle.dev = input_get_device(dev);
1408 evdev->handle.name = dev_name(&evdev->dev);
1409 evdev->handle.handler = handler;
1410 evdev->handle.private = evdev;
1411
1412 evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
1413 evdev->dev.class = &input_class;
1414 evdev->dev.parent = &dev->dev;
1415 evdev->dev.release = evdev_free;
1416 device_initialize(&evdev->dev);
1417
1418 error = input_register_handle(&evdev->handle);
1419 if (error)
1420 goto err_free_evdev;
1421
1422 cdev_init(&evdev->cdev, &evdev_fops);
1423
1424 error = cdev_device_add(&evdev->cdev, &evdev->dev);
1425 if (error)
1426 goto err_cleanup_evdev;
1427
1428 return 0;
1429
1430 err_cleanup_evdev:
1431 evdev_cleanup(evdev);
1432 input_unregister_handle(&evdev->handle);
1433 err_free_evdev:
1434 put_device(&evdev->dev);
1435 err_free_minor:
1436 input_free_minor(minor);
1437 return error;
1438 }
1439
1440 static void evdev_disconnect(struct input_handle *handle)
1441 {
1442 struct evdev *evdev = handle->private;
1443
1444 cdev_device_del(&evdev->cdev, &evdev->dev);
1445 evdev_cleanup(evdev);
1446 input_free_minor(MINOR(evdev->dev.devt));
1447 input_unregister_handle(handle);
1448 put_device(&evdev->dev);
1449 }
1450
1451 static const struct input_device_id evdev_ids[] = {
1452 { .driver_info = 1 }, /* Matches all devices */
1453 { }, /* Terminating zero entry */
1454 };
1455
1456 MODULE_DEVICE_TABLE(input, evdev_ids);
1457
1458 static struct input_handler evdev_handler = {
1459 .event = evdev_event,
1460 .events = evdev_events,
1461 .connect = evdev_connect,
1462 .disconnect = evdev_disconnect,
1463 .legacy_minors = true,
1464 .minor = EVDEV_MINOR_BASE,
1465 .name = "evdev",
1466 .id_table = evdev_ids,
1467 };
1468
1469 static int __init evdev_init(void)
1470 {
1471 return input_register_handler(&evdev_handler);
1472 }
1473
1474 static void __exit evdev_exit(void)
1475 {
1476 input_unregister_handler(&evdev_handler);
1477 }
1478
1479 module_init(evdev_init);
1480 module_exit(evdev_exit);
1481
1482 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1483 MODULE_DESCRIPTION("Input driver event char devices");
1484 MODULE_LICENSE("GPL");
CRIS linux kernel tree