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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
4 * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
5 */
6
7#ifndef __UM_UACCESS_H
8#define __UM_UACCESS_H
9
10#include <asm/elf.h>
11#include <asm/unaligned.h>
12
13#define __under_task_size(addr, size) \
14 (((unsigned long) (addr) < TASK_SIZE) && \
15 (((unsigned long) (addr) + (size)) < TASK_SIZE))
16
17#define __access_ok_vsyscall(addr, size) \
18 (((unsigned long) (addr) >= FIXADDR_USER_START) && \
19 ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
20 ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
21
22#define __addr_range_nowrap(addr, size) \
23 ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
24
25extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
26extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
27extern unsigned long __clear_user(void __user *mem, unsigned long len);
28static inline int __access_ok(const void __user *ptr, unsigned long size);
29
30/* Teach asm-generic/uaccess.h that we have C functions for these. */
31#define __access_ok __access_ok
32#define __clear_user __clear_user
33
34#define INLINE_COPY_FROM_USER
35#define INLINE_COPY_TO_USER
36
37#include <asm-generic/uaccess.h>
38
39static inline int __access_ok(const void __user *ptr, unsigned long size)
40{
41 unsigned long addr = (unsigned long)ptr;
42 return __addr_range_nowrap(addr, size) &&
43 (__under_task_size(addr, size) ||
44 __access_ok_vsyscall(addr, size));
45}
46
47/* no pagefaults for kernel addresses in um */
48#define __get_kernel_nofault(dst, src, type, err_label) \
49do { \
50 *((type *)dst) = get_unaligned((type *)(src)); \
51 if (0) /* make sure the label looks used to the compiler */ \
52 goto err_label; \
53} while (0)
54
55#define __put_kernel_nofault(dst, src, type, err_label) \
56do { \
57 put_unaligned(*((type *)src), (type *)(dst)); \
58 if (0) /* make sure the label looks used to the compiler */ \
59 goto err_label; \
60} while (0)
61
62#endif
1/*
2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
6#ifndef __UM_UACCESS_H
7#define __UM_UACCESS_H
8
9/* thread_info has a mm_segment_t in it, so put the definition up here */
10typedef struct {
11 unsigned long seg;
12} mm_segment_t;
13
14#include <linux/thread_info.h>
15#include <linux/errno.h>
16#include <asm/processor.h>
17#include <asm/elf.h>
18
19#define VERIFY_READ 0
20#define VERIFY_WRITE 1
21
22/*
23 * The fs value determines whether argument validity checking should be
24 * performed or not. If get_fs() == USER_DS, checking is performed, with
25 * get_fs() == KERNEL_DS, checking is bypassed.
26 *
27 * For historical reasons, these macros are grossly misnamed.
28 */
29
30#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
31
32#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
33#define USER_DS MAKE_MM_SEG(TASK_SIZE)
34
35#define get_ds() (KERNEL_DS)
36#define get_fs() (current_thread_info()->addr_limit)
37#define set_fs(x) (current_thread_info()->addr_limit = (x))
38
39#define segment_eq(a, b) ((a).seg == (b).seg)
40
41#define __under_task_size(addr, size) \
42 (((unsigned long) (addr) < TASK_SIZE) && \
43 (((unsigned long) (addr) + (size)) < TASK_SIZE))
44
45#define __access_ok_vsyscall(type, addr, size) \
46 ((type == VERIFY_READ) && \
47 ((unsigned long) (addr) >= FIXADDR_USER_START) && \
48 ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
49 ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
50
51#define __addr_range_nowrap(addr, size) \
52 ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
53
54#define access_ok(type, addr, size) \
55 (__addr_range_nowrap(addr, size) && \
56 (__under_task_size(addr, size) || \
57 __access_ok_vsyscall(type, addr, size) || \
58 segment_eq(get_fs(), KERNEL_DS)))
59
60extern int copy_from_user(void *to, const void __user *from, int n);
61extern int copy_to_user(void __user *to, const void *from, int n);
62
63/*
64 * strncpy_from_user: - Copy a NUL terminated string from userspace.
65 * @dst: Destination address, in kernel space. This buffer must be at
66 * least @count bytes long.
67 * @src: Source address, in user space.
68 * @count: Maximum number of bytes to copy, including the trailing NUL.
69 *
70 * Copies a NUL-terminated string from userspace to kernel space.
71 *
72 * On success, returns the length of the string (not including the trailing
73 * NUL).
74 *
75 * If access to userspace fails, returns -EFAULT (some data may have been
76 * copied).
77 *
78 * If @count is smaller than the length of the string, copies @count bytes
79 * and returns @count.
80 */
81
82extern int strncpy_from_user(char *dst, const char __user *src, int count);
83
84/*
85 * __clear_user: - Zero a block of memory in user space, with less checking.
86 * @to: Destination address, in user space.
87 * @n: Number of bytes to zero.
88 *
89 * Zero a block of memory in user space. Caller must check
90 * the specified block with access_ok() before calling this function.
91 *
92 * Returns number of bytes that could not be cleared.
93 * On success, this will be zero.
94 */
95extern int __clear_user(void __user *mem, int len);
96
97/*
98 * clear_user: - Zero a block of memory in user space.
99 * @to: Destination address, in user space.
100 * @n: Number of bytes to zero.
101 *
102 * Zero a block of memory in user space.
103 *
104 * Returns number of bytes that could not be cleared.
105 * On success, this will be zero.
106 */
107extern int clear_user(void __user *mem, int len);
108
109/*
110 * strlen_user: - Get the size of a string in user space.
111 * @str: The string to measure.
112 * @n: The maximum valid length
113 *
114 * Get the size of a NUL-terminated string in user space.
115 *
116 * Returns the size of the string INCLUDING the terminating NUL.
117 * On exception, returns 0.
118 * If the string is too long, returns a value greater than @n.
119 */
120extern int strnlen_user(const void __user *str, int len);
121
122#define __copy_from_user(to, from, n) copy_from_user(to, from, n)
123
124#define __copy_to_user(to, from, n) copy_to_user(to, from, n)
125
126#define __copy_to_user_inatomic __copy_to_user
127#define __copy_from_user_inatomic __copy_from_user
128
129#define __get_user(x, ptr) \
130({ \
131 const __typeof__(*(ptr)) __user *__private_ptr = (ptr); \
132 __typeof__(x) __private_val; \
133 int __private_ret = -EFAULT; \
134 (x) = (__typeof__(*(__private_ptr)))0; \
135 if (__copy_from_user((__force void *)&__private_val, (__private_ptr),\
136 sizeof(*(__private_ptr))) == 0) { \
137 (x) = (__typeof__(*(__private_ptr))) __private_val; \
138 __private_ret = 0; \
139 } \
140 __private_ret; \
141})
142
143#define get_user(x, ptr) \
144({ \
145 const __typeof__((*(ptr))) __user *private_ptr = (ptr); \
146 (access_ok(VERIFY_READ, private_ptr, sizeof(*private_ptr)) ? \
147 __get_user(x, private_ptr) : ((x) = (__typeof__(*ptr))0, -EFAULT)); \
148})
149
150#define __put_user(x, ptr) \
151({ \
152 __typeof__(*(ptr)) __user *__private_ptr = ptr; \
153 __typeof__(*(__private_ptr)) __private_val; \
154 int __private_ret = -EFAULT; \
155 __private_val = (__typeof__(*(__private_ptr))) (x); \
156 if (__copy_to_user((__private_ptr), &__private_val, \
157 sizeof(*(__private_ptr))) == 0) { \
158 __private_ret = 0; \
159 } \
160 __private_ret; \
161})
162
163#define put_user(x, ptr) \
164({ \
165 __typeof__(*(ptr)) __user *private_ptr = (ptr); \
166 (access_ok(VERIFY_WRITE, private_ptr, sizeof(*private_ptr)) ? \
167 __put_user(x, private_ptr) : -EFAULT); \
168})
169
170#define strlen_user(str) strnlen_user(str, ~0U >> 1)
171
172struct exception_table_entry
173{
174 unsigned long insn;
175 unsigned long fixup;
176};
177
178#endif