Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[sfrench/cifs-2.6.git] / drivers / input / evdev.c
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/module.h>
22 #include <linux/init.h>
23 #include <linux/input/mt.h>
24 #include <linux/major.h>
25 #include <linux/device.h>
26 #include "input-compat.h"
27
28 struct evdev {
29         int open;
30         int minor;
31         struct input_handle handle;
32         wait_queue_head_t wait;
33         struct evdev_client __rcu *grab;
34         struct list_head client_list;
35         spinlock_t client_lock; /* protects client_list */
36         struct mutex mutex;
37         struct device dev;
38         bool exist;
39 };
40
41 struct evdev_client {
42         unsigned int head;
43         unsigned int tail;
44         unsigned int packet_head; /* [future] position of the first element of next packet */
45         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
46         struct fasync_struct *fasync;
47         struct evdev *evdev;
48         struct list_head node;
49         int clkid;
50         unsigned int bufsize;
51         struct input_event buffer[];
52 };
53
54 static struct evdev *evdev_table[EVDEV_MINORS];
55 static DEFINE_MUTEX(evdev_table_mutex);
56
57 static void evdev_pass_event(struct evdev_client *client,
58                              struct input_event *event,
59                              ktime_t mono, ktime_t real)
60 {
61         event->time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
62                                         mono : real);
63
64         /* Interrupts are disabled, just acquire the lock. */
65         spin_lock(&client->buffer_lock);
66
67         client->buffer[client->head++] = *event;
68         client->head &= client->bufsize - 1;
69
70         if (unlikely(client->head == client->tail)) {
71                 /*
72                  * This effectively "drops" all unconsumed events, leaving
73                  * EV_SYN/SYN_DROPPED plus the newest event in the queue.
74                  */
75                 client->tail = (client->head - 2) & (client->bufsize - 1);
76
77                 client->buffer[client->tail].time = event->time;
78                 client->buffer[client->tail].type = EV_SYN;
79                 client->buffer[client->tail].code = SYN_DROPPED;
80                 client->buffer[client->tail].value = 0;
81
82                 client->packet_head = client->tail;
83         }
84
85         if (event->type == EV_SYN && event->code == SYN_REPORT) {
86                 client->packet_head = client->head;
87                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
88         }
89
90         spin_unlock(&client->buffer_lock);
91 }
92
93 /*
94  * Pass incoming event to all connected clients.
95  */
96 static void evdev_event(struct input_handle *handle,
97                         unsigned int type, unsigned int code, int value)
98 {
99         struct evdev *evdev = handle->private;
100         struct evdev_client *client;
101         struct input_event event;
102         ktime_t time_mono, time_real;
103
104         time_mono = ktime_get();
105         time_real = ktime_sub(time_mono, ktime_get_monotonic_offset());
106
107         event.type = type;
108         event.code = code;
109         event.value = value;
110
111         rcu_read_lock();
112
113         client = rcu_dereference(evdev->grab);
114
115         if (client)
116                 evdev_pass_event(client, &event, time_mono, time_real);
117         else
118                 list_for_each_entry_rcu(client, &evdev->client_list, node)
119                         evdev_pass_event(client, &event, time_mono, time_real);
120
121         rcu_read_unlock();
122
123         if (type == EV_SYN && code == SYN_REPORT)
124                 wake_up_interruptible(&evdev->wait);
125 }
126
127 static int evdev_fasync(int fd, struct file *file, int on)
128 {
129         struct evdev_client *client = file->private_data;
130
131         return fasync_helper(fd, file, on, &client->fasync);
132 }
133
134 static int evdev_flush(struct file *file, fl_owner_t id)
135 {
136         struct evdev_client *client = file->private_data;
137         struct evdev *evdev = client->evdev;
138         int retval;
139
140         retval = mutex_lock_interruptible(&evdev->mutex);
141         if (retval)
142                 return retval;
143
144         if (!evdev->exist)
145                 retval = -ENODEV;
146         else
147                 retval = input_flush_device(&evdev->handle, file);
148
149         mutex_unlock(&evdev->mutex);
150         return retval;
151 }
152
153 static void evdev_free(struct device *dev)
154 {
155         struct evdev *evdev = container_of(dev, struct evdev, dev);
156
157         input_put_device(evdev->handle.dev);
158         kfree(evdev);
159 }
160
161 /*
162  * Grabs an event device (along with underlying input device).
163  * This function is called with evdev->mutex taken.
164  */
165 static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
166 {
167         int error;
168
169         if (evdev->grab)
170                 return -EBUSY;
171
172         error = input_grab_device(&evdev->handle);
173         if (error)
174                 return error;
175
176         rcu_assign_pointer(evdev->grab, client);
177
178         return 0;
179 }
180
181 static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
182 {
183         struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
184                                         lockdep_is_held(&evdev->mutex));
185
186         if (grab != client)
187                 return  -EINVAL;
188
189         rcu_assign_pointer(evdev->grab, NULL);
190         synchronize_rcu();
191         input_release_device(&evdev->handle);
192
193         return 0;
194 }
195
196 static void evdev_attach_client(struct evdev *evdev,
197                                 struct evdev_client *client)
198 {
199         spin_lock(&evdev->client_lock);
200         list_add_tail_rcu(&client->node, &evdev->client_list);
201         spin_unlock(&evdev->client_lock);
202 }
203
204 static void evdev_detach_client(struct evdev *evdev,
205                                 struct evdev_client *client)
206 {
207         spin_lock(&evdev->client_lock);
208         list_del_rcu(&client->node);
209         spin_unlock(&evdev->client_lock);
210         synchronize_rcu();
211 }
212
213 static int evdev_open_device(struct evdev *evdev)
214 {
215         int retval;
216
217         retval = mutex_lock_interruptible(&evdev->mutex);
218         if (retval)
219                 return retval;
220
221         if (!evdev->exist)
222                 retval = -ENODEV;
223         else if (!evdev->open++) {
224                 retval = input_open_device(&evdev->handle);
225                 if (retval)
226                         evdev->open--;
227         }
228
229         mutex_unlock(&evdev->mutex);
230         return retval;
231 }
232
233 static void evdev_close_device(struct evdev *evdev)
234 {
235         mutex_lock(&evdev->mutex);
236
237         if (evdev->exist && !--evdev->open)
238                 input_close_device(&evdev->handle);
239
240         mutex_unlock(&evdev->mutex);
241 }
242
243 /*
244  * Wake up users waiting for IO so they can disconnect from
245  * dead device.
246  */
247 static void evdev_hangup(struct evdev *evdev)
248 {
249         struct evdev_client *client;
250
251         spin_lock(&evdev->client_lock);
252         list_for_each_entry(client, &evdev->client_list, node)
253                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
254         spin_unlock(&evdev->client_lock);
255
256         wake_up_interruptible(&evdev->wait);
257 }
258
259 static int evdev_release(struct inode *inode, struct file *file)
260 {
261         struct evdev_client *client = file->private_data;
262         struct evdev *evdev = client->evdev;
263
264         mutex_lock(&evdev->mutex);
265         evdev_ungrab(evdev, client);
266         mutex_unlock(&evdev->mutex);
267
268         evdev_detach_client(evdev, client);
269         kfree(client);
270
271         evdev_close_device(evdev);
272         put_device(&evdev->dev);
273
274         return 0;
275 }
276
277 static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
278 {
279         unsigned int n_events =
280                 max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
281                     EVDEV_MIN_BUFFER_SIZE);
282
283         return roundup_pow_of_two(n_events);
284 }
285
286 static int evdev_open(struct inode *inode, struct file *file)
287 {
288         struct evdev *evdev;
289         struct evdev_client *client;
290         int i = iminor(inode) - EVDEV_MINOR_BASE;
291         unsigned int bufsize;
292         int error;
293
294         if (i >= EVDEV_MINORS)
295                 return -ENODEV;
296
297         error = mutex_lock_interruptible(&evdev_table_mutex);
298         if (error)
299                 return error;
300         evdev = evdev_table[i];
301         if (evdev)
302                 get_device(&evdev->dev);
303         mutex_unlock(&evdev_table_mutex);
304
305         if (!evdev)
306                 return -ENODEV;
307
308         bufsize = evdev_compute_buffer_size(evdev->handle.dev);
309
310         client = kzalloc(sizeof(struct evdev_client) +
311                                 bufsize * sizeof(struct input_event),
312                          GFP_KERNEL);
313         if (!client) {
314                 error = -ENOMEM;
315                 goto err_put_evdev;
316         }
317
318         client->bufsize = bufsize;
319         spin_lock_init(&client->buffer_lock);
320         client->evdev = evdev;
321         evdev_attach_client(evdev, client);
322
323         error = evdev_open_device(evdev);
324         if (error)
325                 goto err_free_client;
326
327         file->private_data = client;
328         nonseekable_open(inode, file);
329
330         return 0;
331
332  err_free_client:
333         evdev_detach_client(evdev, client);
334         kfree(client);
335  err_put_evdev:
336         put_device(&evdev->dev);
337         return error;
338 }
339
340 static ssize_t evdev_write(struct file *file, const char __user *buffer,
341                            size_t count, loff_t *ppos)
342 {
343         struct evdev_client *client = file->private_data;
344         struct evdev *evdev = client->evdev;
345         struct input_event event;
346         int retval = 0;
347
348         if (count != 0 && count < input_event_size())
349                 return -EINVAL;
350
351         retval = mutex_lock_interruptible(&evdev->mutex);
352         if (retval)
353                 return retval;
354
355         if (!evdev->exist) {
356                 retval = -ENODEV;
357                 goto out;
358         }
359
360         while (retval + input_event_size() <= count) {
361
362                 if (input_event_from_user(buffer + retval, &event)) {
363                         retval = -EFAULT;
364                         goto out;
365                 }
366                 retval += input_event_size();
367
368                 input_inject_event(&evdev->handle,
369                                    event.type, event.code, event.value);
370         }
371
372  out:
373         mutex_unlock(&evdev->mutex);
374         return retval;
375 }
376
377 static int evdev_fetch_next_event(struct evdev_client *client,
378                                   struct input_event *event)
379 {
380         int have_event;
381
382         spin_lock_irq(&client->buffer_lock);
383
384         have_event = client->packet_head != client->tail;
385         if (have_event) {
386                 *event = client->buffer[client->tail++];
387                 client->tail &= client->bufsize - 1;
388         }
389
390         spin_unlock_irq(&client->buffer_lock);
391
392         return have_event;
393 }
394
395 static ssize_t evdev_read(struct file *file, char __user *buffer,
396                           size_t count, loff_t *ppos)
397 {
398         struct evdev_client *client = file->private_data;
399         struct evdev *evdev = client->evdev;
400         struct input_event event;
401         size_t read = 0;
402         int error;
403
404         if (count != 0 && count < input_event_size())
405                 return -EINVAL;
406
407         for (;;) {
408                 if (!evdev->exist)
409                         return -ENODEV;
410
411                 if (client->packet_head == client->tail &&
412                     (file->f_flags & O_NONBLOCK))
413                         return -EAGAIN;
414
415                 /*
416                  * count == 0 is special - no IO is done but we check
417                  * for error conditions (see above).
418                  */
419                 if (count == 0)
420                         break;
421
422                 while (read + input_event_size() <= count &&
423                        evdev_fetch_next_event(client, &event)) {
424
425                         if (input_event_to_user(buffer + read, &event))
426                                 return -EFAULT;
427
428                         read += input_event_size();
429                 }
430
431                 if (read)
432                         break;
433
434                 if (!(file->f_flags & O_NONBLOCK)) {
435                         error = wait_event_interruptible(evdev->wait,
436                                         client->packet_head != client->tail ||
437                                         !evdev->exist);
438                         if (error)
439                                 return error;
440                 }
441         }
442
443         return read;
444 }
445
446 /* No kernel lock - fine */
447 static unsigned int evdev_poll(struct file *file, poll_table *wait)
448 {
449         struct evdev_client *client = file->private_data;
450         struct evdev *evdev = client->evdev;
451         unsigned int mask;
452
453         poll_wait(file, &evdev->wait, wait);
454
455         mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
456         if (client->packet_head != client->tail)
457                 mask |= POLLIN | POLLRDNORM;
458
459         return mask;
460 }
461
462 #ifdef CONFIG_COMPAT
463
464 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
465 #define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
466
467 #ifdef __BIG_ENDIAN
468 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
469                         unsigned int maxlen, void __user *p, int compat)
470 {
471         int len, i;
472
473         if (compat) {
474                 len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
475                 if (len > maxlen)
476                         len = maxlen;
477
478                 for (i = 0; i < len / sizeof(compat_long_t); i++)
479                         if (copy_to_user((compat_long_t __user *) p + i,
480                                          (compat_long_t *) bits +
481                                                 i + 1 - ((i % 2) << 1),
482                                          sizeof(compat_long_t)))
483                                 return -EFAULT;
484         } else {
485                 len = BITS_TO_LONGS(maxbit) * sizeof(long);
486                 if (len > maxlen)
487                         len = maxlen;
488
489                 if (copy_to_user(p, bits, len))
490                         return -EFAULT;
491         }
492
493         return len;
494 }
495 #else
496 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
497                         unsigned int maxlen, void __user *p, int compat)
498 {
499         int len = compat ?
500                         BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
501                         BITS_TO_LONGS(maxbit) * sizeof(long);
502
503         if (len > maxlen)
504                 len = maxlen;
505
506         return copy_to_user(p, bits, len) ? -EFAULT : len;
507 }
508 #endif /* __BIG_ENDIAN */
509
510 #else
511
512 static int bits_to_user(unsigned long *bits, unsigned int maxbit,
513                         unsigned int maxlen, void __user *p, int compat)
514 {
515         int len = BITS_TO_LONGS(maxbit) * sizeof(long);
516
517         if (len > maxlen)
518                 len = maxlen;
519
520         return copy_to_user(p, bits, len) ? -EFAULT : len;
521 }
522
523 #endif /* CONFIG_COMPAT */
524
525 static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
526 {
527         int len;
528
529         if (!str)
530                 return -ENOENT;
531
532         len = strlen(str) + 1;
533         if (len > maxlen)
534                 len = maxlen;
535
536         return copy_to_user(p, str, len) ? -EFAULT : len;
537 }
538
539 #define OLD_KEY_MAX     0x1ff
540 static int handle_eviocgbit(struct input_dev *dev,
541                             unsigned int type, unsigned int size,
542                             void __user *p, int compat_mode)
543 {
544         static unsigned long keymax_warn_time;
545         unsigned long *bits;
546         int len;
547
548         switch (type) {
549
550         case      0: bits = dev->evbit;  len = EV_MAX;  break;
551         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
552         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
553         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
554         case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
555         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
556         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
557         case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
558         case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
559         default: return -EINVAL;
560         }
561
562         /*
563          * Work around bugs in userspace programs that like to do
564          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
565          * should be in bytes, not in bits.
566          */
567         if (type == EV_KEY && size == OLD_KEY_MAX) {
568                 len = OLD_KEY_MAX;
569                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
570                         pr_warning("(EVIOCGBIT): Suspicious buffer size %u, "
571                                    "limiting output to %zu bytes. See "
572                                    "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
573                                    OLD_KEY_MAX,
574                                    BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
575         }
576
577         return bits_to_user(bits, len, size, p, compat_mode);
578 }
579 #undef OLD_KEY_MAX
580
581 static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
582 {
583         struct input_keymap_entry ke = {
584                 .len    = sizeof(unsigned int),
585                 .flags  = 0,
586         };
587         int __user *ip = (int __user *)p;
588         int error;
589
590         /* legacy case */
591         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
592                 return -EFAULT;
593
594         error = input_get_keycode(dev, &ke);
595         if (error)
596                 return error;
597
598         if (put_user(ke.keycode, ip + 1))
599                 return -EFAULT;
600
601         return 0;
602 }
603
604 static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
605 {
606         struct input_keymap_entry ke;
607         int error;
608
609         if (copy_from_user(&ke, p, sizeof(ke)))
610                 return -EFAULT;
611
612         error = input_get_keycode(dev, &ke);
613         if (error)
614                 return error;
615
616         if (copy_to_user(p, &ke, sizeof(ke)))
617                 return -EFAULT;
618
619         return 0;
620 }
621
622 static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
623 {
624         struct input_keymap_entry ke = {
625                 .len    = sizeof(unsigned int),
626                 .flags  = 0,
627         };
628         int __user *ip = (int __user *)p;
629
630         if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
631                 return -EFAULT;
632
633         if (get_user(ke.keycode, ip + 1))
634                 return -EFAULT;
635
636         return input_set_keycode(dev, &ke);
637 }
638
639 static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
640 {
641         struct input_keymap_entry ke;
642
643         if (copy_from_user(&ke, p, sizeof(ke)))
644                 return -EFAULT;
645
646         if (ke.len > sizeof(ke.scancode))
647                 return -EINVAL;
648
649         return input_set_keycode(dev, &ke);
650 }
651
652 static int evdev_handle_mt_request(struct input_dev *dev,
653                                    unsigned int size,
654                                    int __user *ip)
655 {
656         const struct input_mt_slot *mt = dev->mt;
657         unsigned int code;
658         int max_slots;
659         int i;
660
661         if (get_user(code, &ip[0]))
662                 return -EFAULT;
663         if (!input_is_mt_value(code))
664                 return -EINVAL;
665
666         max_slots = (size - sizeof(__u32)) / sizeof(__s32);
667         for (i = 0; i < dev->mtsize && i < max_slots; i++)
668                 if (put_user(input_mt_get_value(&mt[i], code), &ip[1 + i]))
669                         return -EFAULT;
670
671         return 0;
672 }
673
674 static long evdev_do_ioctl(struct file *file, unsigned int cmd,
675                            void __user *p, int compat_mode)
676 {
677         struct evdev_client *client = file->private_data;
678         struct evdev *evdev = client->evdev;
679         struct input_dev *dev = evdev->handle.dev;
680         struct input_absinfo abs;
681         struct ff_effect effect;
682         int __user *ip = (int __user *)p;
683         unsigned int i, t, u, v;
684         unsigned int size;
685         int error;
686
687         /* First we check for fixed-length commands */
688         switch (cmd) {
689
690         case EVIOCGVERSION:
691                 return put_user(EV_VERSION, ip);
692
693         case EVIOCGID:
694                 if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
695                         return -EFAULT;
696                 return 0;
697
698         case EVIOCGREP:
699                 if (!test_bit(EV_REP, dev->evbit))
700                         return -ENOSYS;
701                 if (put_user(dev->rep[REP_DELAY], ip))
702                         return -EFAULT;
703                 if (put_user(dev->rep[REP_PERIOD], ip + 1))
704                         return -EFAULT;
705                 return 0;
706
707         case EVIOCSREP:
708                 if (!test_bit(EV_REP, dev->evbit))
709                         return -ENOSYS;
710                 if (get_user(u, ip))
711                         return -EFAULT;
712                 if (get_user(v, ip + 1))
713                         return -EFAULT;
714
715                 input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
716                 input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
717
718                 return 0;
719
720         case EVIOCRMFF:
721                 return input_ff_erase(dev, (int)(unsigned long) p, file);
722
723         case EVIOCGEFFECTS:
724                 i = test_bit(EV_FF, dev->evbit) ?
725                                 dev->ff->max_effects : 0;
726                 if (put_user(i, ip))
727                         return -EFAULT;
728                 return 0;
729
730         case EVIOCGRAB:
731                 if (p)
732                         return evdev_grab(evdev, client);
733                 else
734                         return evdev_ungrab(evdev, client);
735
736         case EVIOCSCLOCKID:
737                 if (copy_from_user(&i, p, sizeof(unsigned int)))
738                         return -EFAULT;
739                 if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
740                         return -EINVAL;
741                 client->clkid = i;
742                 return 0;
743
744         case EVIOCGKEYCODE:
745                 return evdev_handle_get_keycode(dev, p);
746
747         case EVIOCSKEYCODE:
748                 return evdev_handle_set_keycode(dev, p);
749
750         case EVIOCGKEYCODE_V2:
751                 return evdev_handle_get_keycode_v2(dev, p);
752
753         case EVIOCSKEYCODE_V2:
754                 return evdev_handle_set_keycode_v2(dev, p);
755         }
756
757         size = _IOC_SIZE(cmd);
758
759         /* Now check variable-length commands */
760 #define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
761         switch (EVIOC_MASK_SIZE(cmd)) {
762
763         case EVIOCGPROP(0):
764                 return bits_to_user(dev->propbit, INPUT_PROP_MAX,
765                                     size, p, compat_mode);
766
767         case EVIOCGMTSLOTS(0):
768                 return evdev_handle_mt_request(dev, size, ip);
769
770         case EVIOCGKEY(0):
771                 return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
772
773         case EVIOCGLED(0):
774                 return bits_to_user(dev->led, LED_MAX, size, p, compat_mode);
775
776         case EVIOCGSND(0):
777                 return bits_to_user(dev->snd, SND_MAX, size, p, compat_mode);
778
779         case EVIOCGSW(0):
780                 return bits_to_user(dev->sw, SW_MAX, size, p, compat_mode);
781
782         case EVIOCGNAME(0):
783                 return str_to_user(dev->name, size, p);
784
785         case EVIOCGPHYS(0):
786                 return str_to_user(dev->phys, size, p);
787
788         case EVIOCGUNIQ(0):
789                 return str_to_user(dev->uniq, size, p);
790
791         case EVIOC_MASK_SIZE(EVIOCSFF):
792                 if (input_ff_effect_from_user(p, size, &effect))
793                         return -EFAULT;
794
795                 error = input_ff_upload(dev, &effect, file);
796
797                 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
798                         return -EFAULT;
799
800                 return error;
801         }
802
803         /* Multi-number variable-length handlers */
804         if (_IOC_TYPE(cmd) != 'E')
805                 return -EINVAL;
806
807         if (_IOC_DIR(cmd) == _IOC_READ) {
808
809                 if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
810                         return handle_eviocgbit(dev,
811                                                 _IOC_NR(cmd) & EV_MAX, size,
812                                                 p, compat_mode);
813
814                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
815
816                         if (!dev->absinfo)
817                                 return -EINVAL;
818
819                         t = _IOC_NR(cmd) & ABS_MAX;
820                         abs = dev->absinfo[t];
821
822                         if (copy_to_user(p, &abs, min_t(size_t,
823                                         size, sizeof(struct input_absinfo))))
824                                 return -EFAULT;
825
826                         return 0;
827                 }
828         }
829
830         if (_IOC_DIR(cmd) == _IOC_WRITE) {
831
832                 if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
833
834                         if (!dev->absinfo)
835                                 return -EINVAL;
836
837                         t = _IOC_NR(cmd) & ABS_MAX;
838
839                         if (copy_from_user(&abs, p, min_t(size_t,
840                                         size, sizeof(struct input_absinfo))))
841                                 return -EFAULT;
842
843                         if (size < sizeof(struct input_absinfo))
844                                 abs.resolution = 0;
845
846                         /* We can't change number of reserved MT slots */
847                         if (t == ABS_MT_SLOT)
848                                 return -EINVAL;
849
850                         /*
851                          * Take event lock to ensure that we are not
852                          * changing device parameters in the middle
853                          * of event.
854                          */
855                         spin_lock_irq(&dev->event_lock);
856                         dev->absinfo[t] = abs;
857                         spin_unlock_irq(&dev->event_lock);
858
859                         return 0;
860                 }
861         }
862
863         return -EINVAL;
864 }
865
866 static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
867                                 void __user *p, int compat_mode)
868 {
869         struct evdev_client *client = file->private_data;
870         struct evdev *evdev = client->evdev;
871         int retval;
872
873         retval = mutex_lock_interruptible(&evdev->mutex);
874         if (retval)
875                 return retval;
876
877         if (!evdev->exist) {
878                 retval = -ENODEV;
879                 goto out;
880         }
881
882         retval = evdev_do_ioctl(file, cmd, p, compat_mode);
883
884  out:
885         mutex_unlock(&evdev->mutex);
886         return retval;
887 }
888
889 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
890 {
891         return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
892 }
893
894 #ifdef CONFIG_COMPAT
895 static long evdev_ioctl_compat(struct file *file,
896                                 unsigned int cmd, unsigned long arg)
897 {
898         return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
899 }
900 #endif
901
902 static const struct file_operations evdev_fops = {
903         .owner          = THIS_MODULE,
904         .read           = evdev_read,
905         .write          = evdev_write,
906         .poll           = evdev_poll,
907         .open           = evdev_open,
908         .release        = evdev_release,
909         .unlocked_ioctl = evdev_ioctl,
910 #ifdef CONFIG_COMPAT
911         .compat_ioctl   = evdev_ioctl_compat,
912 #endif
913         .fasync         = evdev_fasync,
914         .flush          = evdev_flush,
915         .llseek         = no_llseek,
916 };
917
918 static int evdev_install_chrdev(struct evdev *evdev)
919 {
920         /*
921          * No need to do any locking here as calls to connect and
922          * disconnect are serialized by the input core
923          */
924         evdev_table[evdev->minor] = evdev;
925         return 0;
926 }
927
928 static void evdev_remove_chrdev(struct evdev *evdev)
929 {
930         /*
931          * Lock evdev table to prevent race with evdev_open()
932          */
933         mutex_lock(&evdev_table_mutex);
934         evdev_table[evdev->minor] = NULL;
935         mutex_unlock(&evdev_table_mutex);
936 }
937
938 /*
939  * Mark device non-existent. This disables writes, ioctls and
940  * prevents new users from opening the device. Already posted
941  * blocking reads will stay, however new ones will fail.
942  */
943 static void evdev_mark_dead(struct evdev *evdev)
944 {
945         mutex_lock(&evdev->mutex);
946         evdev->exist = false;
947         mutex_unlock(&evdev->mutex);
948 }
949
950 static void evdev_cleanup(struct evdev *evdev)
951 {
952         struct input_handle *handle = &evdev->handle;
953
954         evdev_mark_dead(evdev);
955         evdev_hangup(evdev);
956         evdev_remove_chrdev(evdev);
957
958         /* evdev is marked dead so no one else accesses evdev->open */
959         if (evdev->open) {
960                 input_flush_device(handle, NULL);
961                 input_close_device(handle);
962         }
963 }
964
965 /*
966  * Create new evdev device. Note that input core serializes calls
967  * to connect and disconnect so we don't need to lock evdev_table here.
968  */
969 static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
970                          const struct input_device_id *id)
971 {
972         struct evdev *evdev;
973         int minor;
974         int error;
975
976         for (minor = 0; minor < EVDEV_MINORS; minor++)
977                 if (!evdev_table[minor])
978                         break;
979
980         if (minor == EVDEV_MINORS) {
981                 pr_err("no more free evdev devices\n");
982                 return -ENFILE;
983         }
984
985         evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
986         if (!evdev)
987                 return -ENOMEM;
988
989         INIT_LIST_HEAD(&evdev->client_list);
990         spin_lock_init(&evdev->client_lock);
991         mutex_init(&evdev->mutex);
992         init_waitqueue_head(&evdev->wait);
993
994         dev_set_name(&evdev->dev, "event%d", minor);
995         evdev->exist = true;
996         evdev->minor = minor;
997
998         evdev->handle.dev = input_get_device(dev);
999         evdev->handle.name = dev_name(&evdev->dev);
1000         evdev->handle.handler = handler;
1001         evdev->handle.private = evdev;
1002
1003         evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
1004         evdev->dev.class = &input_class;
1005         evdev->dev.parent = &dev->dev;
1006         evdev->dev.release = evdev_free;
1007         device_initialize(&evdev->dev);
1008
1009         error = input_register_handle(&evdev->handle);
1010         if (error)
1011                 goto err_free_evdev;
1012
1013         error = evdev_install_chrdev(evdev);
1014         if (error)
1015                 goto err_unregister_handle;
1016
1017         error = device_add(&evdev->dev);
1018         if (error)
1019                 goto err_cleanup_evdev;
1020
1021         return 0;
1022
1023  err_cleanup_evdev:
1024         evdev_cleanup(evdev);
1025  err_unregister_handle:
1026         input_unregister_handle(&evdev->handle);
1027  err_free_evdev:
1028         put_device(&evdev->dev);
1029         return error;
1030 }
1031
1032 static void evdev_disconnect(struct input_handle *handle)
1033 {
1034         struct evdev *evdev = handle->private;
1035
1036         device_del(&evdev->dev);
1037         evdev_cleanup(evdev);
1038         input_unregister_handle(handle);
1039         put_device(&evdev->dev);
1040 }
1041
1042 static const struct input_device_id evdev_ids[] = {
1043         { .driver_info = 1 },   /* Matches all devices */
1044         { },                    /* Terminating zero entry */
1045 };
1046
1047 MODULE_DEVICE_TABLE(input, evdev_ids);
1048
1049 static struct input_handler evdev_handler = {
1050         .event          = evdev_event,
1051         .connect        = evdev_connect,
1052         .disconnect     = evdev_disconnect,
1053         .fops           = &evdev_fops,
1054         .minor          = EVDEV_MINOR_BASE,
1055         .name           = "evdev",
1056         .id_table       = evdev_ids,
1057 };
1058
1059 static int __init evdev_init(void)
1060 {
1061         return input_register_handler(&evdev_handler);
1062 }
1063
1064 static void __exit evdev_exit(void)
1065 {
1066         input_unregister_handler(&evdev_handler);
1067 }
1068
1069 module_init(evdev_init);
1070 module_exit(evdev_exit);
1071
1072 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
1073 MODULE_DESCRIPTION("Input driver event char devices");
1074 MODULE_LICENSE("GPL");