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Linux kernel mirror (for testing)
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linux
1#ifndef __V850_UACCESS_H__
2#define __V850_UACCESS_H__
3
4/*
5 * User space memory access functions
6 */
7
8#include <linux/errno.h>
9#include <linux/string.h>
10
11#include <asm/segment.h>
12#include <asm/machdep.h>
13
14#define VERIFY_READ 0
15#define VERIFY_WRITE 1
16
17extern inline int access_ok (int type, const void *addr, unsigned long size)
18{
19 /* XXX I guess we should check against real ram bounds at least, and
20 possibly make sure ADDR is not within the kernel.
21 For now we just check to make sure it's not a small positive
22 or negative value, as that will at least catch some kinds of
23 error. In particular, we make sure that ADDR's not within the
24 interrupt vector area, which we know starts at zero, or within the
25 peripheral-I/O area, which is located just _before_ zero. */
26 unsigned long val = (unsigned long)addr;
27 return val >= (0x80 + NUM_CPU_IRQS*16) && val < 0xFFFFF000;
28}
29
30/*
31 * The exception table consists of pairs of addresses: the first is the
32 * address of an instruction that is allowed to fault, and the second is
33 * the address at which the program should continue. No registers are
34 * modified, so it is entirely up to the continuation code to figure out
35 * what to do.
36 *
37 * All the routines below use bits of fixup code that are out of line
38 * with the main instruction path. This means when everything is well,
39 * we don't even have to jump over them. Further, they do not intrude
40 * on our cache or tlb entries.
41 */
42
43struct exception_table_entry
44{
45 unsigned long insn, fixup;
46};
47
48/* Returns 0 if exception not found and fixup otherwise. */
49extern unsigned long search_exception_table (unsigned long);
50
51
52/*
53 * These are the main single-value transfer routines. They automatically
54 * use the right size if we just have the right pointer type.
55 */
56
57extern int bad_user_access_length (void);
58
59#define __get_user(var, ptr) \
60 ({ \
61 int __gu_err = 0; \
62 typeof(*(ptr)) __gu_val = 0; \
63 switch (sizeof (*(ptr))) { \
64 case 1: \
65 case 2: \
66 case 4: \
67 __gu_val = *(ptr); \
68 break; \
69 case 8: \
70 memcpy(&__gu_val, ptr, sizeof(__gu_val)); \
71 break; \
72 default: \
73 __gu_val = 0; \
74 __gu_err = __get_user_bad (); \
75 break; \
76 } \
77 (var) = __gu_val; \
78 __gu_err; \
79 })
80#define __get_user_bad() (bad_user_access_length (), (-EFAULT))
81
82#define __put_user(var, ptr) \
83 ({ \
84 int __pu_err = 0; \
85 switch (sizeof (*(ptr))) { \
86 case 1: \
87 case 2: \
88 case 4: \
89 *(ptr) = (var); \
90 break; \
91 case 8: { \
92 typeof(*(ptr)) __pu_val = 0; \
93 memcpy(ptr, &__pu_val, sizeof(__pu_val)); \
94 } \
95 break; \
96 default: \
97 __pu_err = __put_user_bad (); \
98 break; \
99 } \
100 __pu_err; \
101 })
102#define __put_user_bad() (bad_user_access_length (), (-EFAULT))
103
104#define put_user(x, ptr) __put_user(x, ptr)
105#define get_user(x, ptr) __get_user(x, ptr)
106
107#define __copy_from_user(to, from, n) (memcpy (to, from, n), 0)
108#define __copy_to_user(to, from, n) (memcpy(to, from, n), 0)
109
110#define __copy_to_user_inatomic __copy_to_user
111#define __copy_from_user_inatomic __copy_from_user
112
113#define copy_from_user(to, from, n) __copy_from_user (to, from, n)
114#define copy_to_user(to, from, n) __copy_to_user(to, from, n)
115
116#define copy_to_user_ret(to,from,n,retval) \
117 ({ if (copy_to_user (to,from,n)) return retval; })
118
119#define copy_from_user_ret(to,from,n,retval) \
120 ({ if (copy_from_user (to,from,n)) return retval; })
121
122/*
123 * Copy a null terminated string from userspace.
124 */
125
126static inline long
127strncpy_from_user (char *dst, const char *src, long count)
128{
129 char *tmp;
130 strncpy (dst, src, count);
131 for (tmp = dst; *tmp && count > 0; tmp++, count--)
132 ;
133 return tmp - dst;
134}
135
136/*
137 * Return the size of a string (including the ending 0)
138 *
139 * Return 0 on exception, a value greater than N if too long
140 */
141static inline long strnlen_user (const char *src, long n)
142{
143 return strlen (src) + 1;
144}
145
146#define strlen_user(str) strnlen_user (str, 32767)
147
148/*
149 * Zero Userspace
150 */
151
152static inline unsigned long
153clear_user (void *to, unsigned long n)
154{
155 memset (to, 0, n);
156 return 0;
157}
158
159#endif /* __V850_UACCESS_H__ */