1 #ifndef __M68KNOMMU_UACCESS_H
2 #define __M68KNOMMU_UACCESS_H
3
4 /*
5 * User space memory access functions
6 */
7 #include <linux/sched.h>
8 #include <linux/mm.h>
9 #include <linux/string.h>
10
11 #include <asm/segment.h>
12
13 #define VERIFY_READ 0
14 #define VERIFY_WRITE 1
15
16 #define access_ok(type,addr,size) _access_ok((unsigned long)(addr),(size))
17
18 /*
19 * It is not enough to just have access_ok check for a real RAM address.
20 * This would disallow the case of code/ro-data running XIP in flash/rom.
21 * Ideally we would check the possible flash ranges too, but that is
22 * currently not so easy.
23 */
_access_ok(unsigned long addr,unsigned long size)24 static inline int _access_ok(unsigned long addr, unsigned long size)
25 {
26 return 1;
27 }
28
29 /*
30 * The exception table consists of pairs of addresses: the first is the
31 * address of an instruction that is allowed to fault, and the second is
32 * the address at which the program should continue. No registers are
33 * modified, so it is entirely up to the continuation code to figure out
34 * what to do.
35 *
36 * All the routines below use bits of fixup code that are out of line
37 * with the main instruction path. This means when everything is well,
38 * we don't even have to jump over them. Further, they do not intrude
39 * on our cache or tlb entries.
40 */
41
42 struct exception_table_entry
43 {
44 unsigned long insn, fixup;
45 };
46
47 /* Returns 0 if exception not found and fixup otherwise. */
48 extern unsigned long search_exception_table(unsigned long);
49
50
51 /*
52 * These are the main single-value transfer routines. They automatically
53 * use the right size if we just have the right pointer type.
54 */
55
56 #define put_user(x, ptr) \
57 ({ \
58 int __pu_err = 0; \
59 typeof(*(ptr)) __pu_val = (x); \
60 switch (sizeof (*(ptr))) { \
61 case 1: \
62 __put_user_asm(__pu_err, __pu_val, ptr, b); \
63 break; \
64 case 2: \
65 __put_user_asm(__pu_err, __pu_val, ptr, w); \
66 break; \
67 case 4: \
68 __put_user_asm(__pu_err, __pu_val, ptr, l); \
69 break; \
70 case 8: \
71 memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
72 break; \
73 default: \
74 __pu_err = __put_user_bad(); \
75 break; \
76 } \
77 __pu_err; \
78 })
79 #define __put_user(x, ptr) put_user(x, ptr)
80
81 extern int __put_user_bad(void);
82
83 /*
84 * Tell gcc we read from memory instead of writing: this is because
85 * we do not write to any memory gcc knows about, so there are no
86 * aliasing issues.
87 */
88
89 #define __ptr(x) ((unsigned long *)(x))
90
91 #define __put_user_asm(err,x,ptr,bwl) \
92 __asm__ ("move" #bwl " %0,%1" \
93 : /* no outputs */ \
94 :"d" (x),"m" (*__ptr(ptr)) : "memory")
95
96 #define get_user(x, ptr) \
97 ({ \
98 int __gu_err = 0; \
99 typeof(x) __gu_val = 0; \
100 switch (sizeof(*(ptr))) { \
101 case 1: \
102 __get_user_asm(__gu_err, __gu_val, ptr, b, "=d"); \
103 break; \
104 case 2: \
105 __get_user_asm(__gu_err, __gu_val, ptr, w, "=r"); \
106 break; \
107 case 4: \
108 __get_user_asm(__gu_err, __gu_val, ptr, l, "=r"); \
109 break; \
110 case 8: \
111 memcpy((void *) &__gu_val, ptr, sizeof (*(ptr))); \
112 break; \
113 default: \
114 __gu_val = 0; \
115 __gu_err = __get_user_bad(); \
116 break; \
117 } \
118 (x) = (typeof(*(ptr))) __gu_val; \
119 __gu_err; \
120 })
121 #define __get_user(x, ptr) get_user(x, ptr)
122
123 extern int __get_user_bad(void);
124
125 #define __get_user_asm(err,x,ptr,bwl,reg) \
126 __asm__ ("move" #bwl " %1,%0" \
127 : "=d" (x) \
128 : "m" (*__ptr(ptr)))
129
130 #define copy_from_user(to, from, n) (memcpy(to, from, n), 0)
131 #define copy_to_user(to, from, n) (memcpy(to, from, n), 0)
132
133 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
134 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
135 #define __copy_to_user_inatomic __copy_to_user
136 #define __copy_from_user_inatomic __copy_from_user
137
138 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
139
140 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
141
142 /*
143 * Copy a null terminated string from userspace.
144 */
145
146 static inline long
strncpy_from_user(char * dst,const char * src,long count)147 strncpy_from_user(char *dst, const char *src, long count)
148 {
149 char *tmp;
150 strncpy(dst, src, count);
151 for (tmp = dst; *tmp && count > 0; tmp++, count--)
152 ;
153 return(tmp - dst); /* DAVIDM should we count a NUL ? check getname */
154 }
155
156 /*
157 * Return the size of a string (including the ending 0)
158 *
159 * Return 0 on exception, a value greater than N if too long
160 */
strnlen_user(const char * src,long n)161 static inline long strnlen_user(const char *src, long n)
162 {
163 return(strlen(src) + 1); /* DAVIDM make safer */
164 }
165
166 #define strlen_user(str) strnlen_user(str, 32767)
167
168 /*
169 * Zero Userspace
170 */
171
172 static inline unsigned long
__clear_user(void * to,unsigned long n)173 __clear_user(void *to, unsigned long n)
174 {
175 memset(to, 0, n);
176 return 0;
177 }
178
179 #define clear_user(to,n) __clear_user(to,n)
180
181 #endif /* _M68KNOMMU_UACCESS_H */
182