drivers/input/input-compat.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * 32bit compatibility wrappers for the input subsystem.
   4  *
   5  * Very heavily based on evdev.c - Copyright (c) 1999-2002 Vojtech Pavlik
   6  */
   7
   8 #include <linux/export.h>
   9 #include <linux/uaccess.h>
  10 #include "input-compat.h"
  11
  12 #ifdef CONFIG_COMPAT
  13
  14 int input_event_from_user(const char __user *buffer,
  15                           struct input_event *event)
  16 {
  17         if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
  18                 struct input_event_compat compat_event;
  19
  20                 if (copy_from_user(&compat_event, buffer,
  21                                    sizeof(struct input_event_compat)))
  22                         return -EFAULT;
  23
  24                 event->input_event_sec = compat_event.sec;
  25                 event->input_event_usec = compat_event.usec;
  26                 event->type = compat_event.type;
  27                 event->code = compat_event.code;
  28                 event->value = compat_event.value;
  29
  30         } else {
  31                 if (copy_from_user(event, buffer, sizeof(struct input_event)))
  32                         return -EFAULT;
  33         }
  34
  35         return 0;
  36 }
  37
  38 int input_event_to_user(char __user *buffer,
  39                         const struct input_event *event)
  40 {
  41         if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
  42                 struct input_event_compat compat_event;
  43
  44                 compat_event.sec = event->input_event_sec;
  45                 compat_event.usec = event->input_event_usec;
  46                 compat_event.type = event->type;
  47                 compat_event.code = event->code;
  48                 compat_event.value = event->value;
  49
  50                 if (copy_to_user(buffer, &compat_event,
  51                                  sizeof(struct input_event_compat)))
  52                         return -EFAULT;
  53
  54         } else {
  55                 if (copy_to_user(buffer, event, sizeof(struct input_event)))
  56                         return -EFAULT;
  57         }
  58
  59         return 0;
  60 }
  61
  62 int input_ff_effect_from_user(const char __user *buffer, size_t size,
  63                               struct ff_effect *effect)
  64 {
  65         if (in_compat_syscall()) {
  66                 struct ff_effect_compat *compat_effect;
  67
  68                 if (size != sizeof(struct ff_effect_compat))
  69                         return -EINVAL;
  70
  71                 /*
  72                  * It so happens that the pointer which needs to be changed
  73                  * is the last field in the structure, so we can retrieve the
  74                  * whole thing and replace just the pointer.
  75                  */
  76                 compat_effect = (struct ff_effect_compat *)effect;
  77
  78                 if (copy_from_user(compat_effect, buffer,
  79                                    sizeof(struct ff_effect_compat)))
  80                         return -EFAULT;
  81
  82                 if (compat_effect->type == FF_PERIODIC &&
  83                     compat_effect->u.periodic.waveform == FF_CUSTOM)
  84                         effect->u.periodic.custom_data =
  85                                 compat_ptr(compat_effect->u.periodic.custom_data);
  86         } else {
  87                 if (size != sizeof(struct ff_effect))
  88                         return -EINVAL;
  89
  90                 if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
  91                         return -EFAULT;
  92         }
  93
  94         return 0;
  95 }
  96
  97 #else
  98
  99 int input_event_from_user(const char __user *buffer,
 100                          struct input_event *event)
 101 {
 102         if (copy_from_user(event, buffer, sizeof(struct input_event)))
 103                 return -EFAULT;
 104
 105         return 0;
 106 }
 107
 108 int input_event_to_user(char __user *buffer,
 109                         const struct input_event *event)
 110 {
 111         if (copy_to_user(buffer, event, sizeof(struct input_event)))
 112                 return -EFAULT;
 113
 114         return 0;
 115 }
 116
 117 int input_ff_effect_from_user(const char __user *buffer, size_t size,
 118                               struct ff_effect *effect)
 119 {
 120         if (size != sizeof(struct ff_effect))
 121                 return -EINVAL;
 122
 123         if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
 124                 return -EFAULT;
 125
 126         return 0;
 127 }
 128
 129 #endif /* CONFIG_COMPAT */
 130
 131 EXPORT_SYMBOL_GPL(input_event_from_user);
 132 EXPORT_SYMBOL_GPL(input_event_to_user);
 133 EXPORT_SYMBOL_GPL(input_ff_effect_from_user);