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