1 /* $NetBSD: uaccess.h,v 1.11 2022/10/25 23:38:33 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef _ASM_UACCESS_H_
33 #define _ASM_UACCESS_H_
34
35 #include <sys/types.h>
36 #include <sys/errno.h>
37 #include <sys/systm.h>
38
39 #include <linux/compiler.h>
40
41 /* XXX This is a cop-out. */
42 #define VERIFY_READ 0
43 #define VERIFY_WRITE 1
44 static inline bool
access_ok(const void * uaddr __unused,size_t nbytes __unused)45 access_ok(const void *uaddr __unused, size_t nbytes __unused)
46 {
47 return true;
48 }
49
50 #define __copy_from_user copy_from_user
51 #define __copy_to_user copy_to_user
52
53 static inline int
copy_from_user(void * kernel_addr,const void * user_addr,size_t len)54 copy_from_user(void *kernel_addr, const void *user_addr, size_t len)
55 {
56 /* XXX errno NetBSD->Linux */
57 return -copyin(user_addr, kernel_addr, len);
58 }
59
60 static inline long
strncpy_from_user(char * kernel_addr,const void * user_addr,long len)61 strncpy_from_user(char *kernel_addr, const void *user_addr, long len)
62 {
63 size_t done;
64 int error;
65
66 if (len <= 0)
67 return 0;
68 error = copyinstr(user_addr, kernel_addr, len, &done);
69 if (error)
70 return error;
71 KASSERT(done <= (size_t)len);
72 KASSERT(done >= 1);
73 return done - 1;
74 }
75
76 static inline int
copy_to_user(void * user_addr,const void * kernel_addr,size_t len)77 copy_to_user(void *user_addr, const void *kernel_addr, size_t len)
78 {
79 /* XXX errno NetBSD->Linux */
80 return -copyout(kernel_addr, user_addr, len);
81 }
82
83 #define get_user(KERNEL_LVAL, USER_PTR) \
84 copy_from_user(&(KERNEL_LVAL), (USER_PTR), sizeof(*(USER_PTR)) + \
85 0*sizeof(&(KERNEL_LVAL) - (USER_PTR)))
86
87 #define put_user(KERNEL_RVAL, USER_PTR) ({ \
88 const typeof(*(USER_PTR)) __put_user_tmp = (KERNEL_RVAL); \
89 copy_to_user((USER_PTR), &__put_user_tmp, sizeof(__put_user_tmp)); \
90 })
91
92 #define __get_user get_user
93 #define __put_user put_user
94
95 #define user_access_begin(P,N) access_ok(P,N)
96 #define user_access_end() __nothing
97
98 #define unsafe_put_user(KERNEL_RVAL, USER_PTR, LABEL) do { \
99 if (__put_user(KERNEL_RVAL, USER_PTR)) \
100 goto LABEL; \
101 } while (0)
102
103 static inline size_t
clear_user(void __user * user_ptr,size_t size)104 clear_user(void __user *user_ptr, size_t size)
105 {
106 char __user *p = user_ptr;
107 size_t n = size;
108
109 /*
110 * This loop which sets up a fault handler on every iteration
111 * is not going to win any speed records, but it'll do to copy
112 * out an int.
113 */
114 while (n --> 0) {
115 if (ustore_char(p, 0) != 0)
116 return ++n;
117 }
118
119 return 0;
120 }
121
122 #if 0
123 /*
124 * XXX These `inatomic' versions are a cop out, but they should do for
125 * now -- they are used only in fast paths which can't fault but which
126 * can fall back to slower paths that arrange things so faulting is OK.
127 */
128
129 static inline int
130 __copy_from_user_inatomic(void *kernel_addr __unused,
131 const void *user_addr __unused, size_t len __unused)
132 {
133 return -EFAULT;
134 }
135
136 static inline int
137 __copy_to_user_inatomic(void *user_addr __unused,
138 const void *kernel_addr __unused, size_t len __unused)
139 {
140 return -EFAULT;
141 }
142 #endif /* 0 */
143
144 static inline int
__copy_from_user_inatomic_nocache(void * kernel_addr __unused,const void * user_addr __unused,size_t len __unused)145 __copy_from_user_inatomic_nocache(void *kernel_addr __unused,
146 const void *user_addr __unused, size_t len __unused)
147 {
148 return -EFAULT;
149 }
150
151 #endif /* _ASM_UACCESS_H_ */
152