xref: /linux/drivers/input/input-compat.c (revision 37744feebc086908fd89760650f458ab19071750)
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);
134