drivers/input/input-compat.c

   1 /*
   2  * 32bit compatibility wrappers for the input subsystem.
   3  *
   4  * Very heavily based on evdev.c - 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 #include <linux/export.h>
  12 #include <linux/uaccess.h>
  13 #include "input-compat.h"
  14
  15 #ifdef CONFIG_COMPAT
  16
  17 int input_event_from_user(const char __user *buffer,
  18                           struct input_event *event)
  19 {
  20         if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
  21                 struct input_event_compat compat_event;
  22
  23                 if (copy_from_user(&compat_event, buffer,
  24                                    sizeof(struct input_event_compat)))
  25                         return -EFAULT;
  26
  27                 event->input_event_sec = compat_event.sec;
  28                 event->input_event_usec = compat_event.usec;
  29                 event->type = compat_event.type;
  30                 event->code = compat_event.code;
  31                 event->value = compat_event.value;
  32
  33         } else {
  34                 if (copy_from_user(event, buffer, sizeof(struct input_event)))
  35                         return -EFAULT;
  36         }
  37
  38         return 0;
  39 }
  40
  41 int input_event_to_user(char __user *buffer,
  42                         const struct input_event *event)
  43 {
  44         if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
  45                 struct input_event_compat compat_event;
  46
  47                 compat_event.sec = event->input_event_sec;
  48                 compat_event.usec = event->input_event_usec;
  49                 compat_event.type = event->type;
  50                 compat_event.code = event->code;
  51                 compat_event.value = event->value;
  52
  53                 if (copy_to_user(buffer, &compat_event,
  54                                  sizeof(struct input_event_compat)))
  55                         return -EFAULT;
  56
  57         } else {
  58                 if (copy_to_user(buffer, event, sizeof(struct input_event)))
  59                         return -EFAULT;
  60         }
  61
  62         return 0;
  63 }
  64
  65 int input_ff_effect_from_user(const char __user *buffer, size_t size,
  66                               struct ff_effect *effect)
  67 {
  68         if (in_compat_syscall()) {
  69                 struct ff_effect_compat *compat_effect;
  70
  71                 if (size != sizeof(struct ff_effect_compat))
  72                         return -EINVAL;
  73
  74                 /*
  75                  * It so happens that the pointer which needs to be changed
  76                  * is the last field in the structure, so we can retrieve the
  77                  * whole thing and replace just the pointer.
  78                  */
  79                 compat_effect = (struct ff_effect_compat *)effect;
  80
  81                 if (copy_from_user(compat_effect, buffer,
  82                                    sizeof(struct ff_effect_compat)))
  83                         return -EFAULT;
  84
  85                 if (compat_effect->type == FF_PERIODIC &&
  86                     compat_effect->u.periodic.waveform == FF_CUSTOM)
  87                         effect->u.periodic.custom_data =
  88                                 compat_ptr(compat_effect->u.periodic.custom_data);
  89         } else {
  90                 if (size != sizeof(struct ff_effect))
  91                         return -EINVAL;
  92
  93                 if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
  94                         return -EFAULT;
  95         }
  96
  97         return 0;
  98 }
  99
 100 #else
 101
 102 int input_event_from_user(const char __user *buffer,
 103                          struct input_event *event)
 104 {
 105         if (copy_from_user(event, buffer, sizeof(struct input_event)))
 106                 return -EFAULT;
 107
 108         return 0;
 109 }
 110
 111 int input_event_to_user(char __user *buffer,
 112                         const struct input_event *event)
 113 {
 114         if (copy_to_user(buffer, event, sizeof(struct input_event)))
 115                 return -EFAULT;
 116
 117         return 0;
 118 }
 119
 120 int input_ff_effect_from_user(const char __user *buffer, size_t size,
 121                               struct ff_effect *effect)
 122 {
 123         if (size != sizeof(struct ff_effect))
 124                 return -EINVAL;
 125
 126         if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
 127                 return -EFAULT;
 128
 129         return 0;
 130 }
 131
 132 #endif /* CONFIG_COMPAT */
 133
 134 EXPORT_SYMBOL_GPL(input_event_from_user);
 135 EXPORT_SYMBOL_GPL(input_event_to_user);
 136 EXPORT_SYMBOL_GPL(input_ff_effect_from_user);