1 #ifndef _ASMARM_UACCESS_H
2 #define _ASMARM_UACCESS_H
3
4 /*
5 * User space memory access functions
6 */
7 #include <linux/sched.h>
8 #include <asm/errno.h>
9
10 #define VERIFY_READ 0
11 #define VERIFY_WRITE 1
12
13 /*
14 * The exception table consists of pairs of addresses: the first is the
15 * address of an instruction that is allowed to fault, and the second is
16 * the address at which the program should continue. No registers are
17 * modified, so it is entirely up to the continuation code to figure out
18 * what to do.
19 *
20 * All the routines below use bits of fixup code that are out of line
21 * with the main instruction path. This means when everything is well,
22 * we don't even have to jump over them. Further, they do not intrude
23 * on our cache or tlb entries.
24 */
25
26 struct exception_table_entry
27 {
28 unsigned long insn, fixup;
29 };
30
31 /* Returns 0 if exception not found and fixup otherwise. */
32 extern unsigned long search_exception_table(unsigned long);
33
34 #define get_ds() (KERNEL_DS)
35 #define get_fs() (current->addr_limit)
36 #define segment_eq(a,b) ((a) == (b))
37
38 #include <asm/proc/uaccess.h>
39
40 #define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
41
42 extern __inline__ int verify_area(int type, const void * addr, unsigned long size)
43 {
44 return access_ok(type, addr, size) ? 0 : -EFAULT;
45 }
46
47 /*
48 * Single-value transfer routines. They automatically use the right
49 * size if we just have the right pointer type. Note that the functions
50 * which read from user space (*get_*) need to take care not to leak
51 * kernel data even if the calling code is buggy and fails to check
52 * the return value. This means zeroing out the destination variable
53 * or buffer on error. Normally this is done out of line by the
54 * fixup code, but there are a few places where it intrudes on the
55 * main code path. When we only write to user space, there is no
56 * problem.
57 *
58 * The "__xxx" versions of the user access functions do not verify the
59 * address space - it must have been done previously with a separate
60 * "access_ok()" call.
61 *
62 * The "xxx_error" versions set the third argument to EFAULT if an
63 * error occurs, and leave it unchanged on success. Note that these
64 * versions are void (ie, don't return a value as such).
65 */
66 #define get_user(x,p) __get_user_check((x),(p),sizeof(*(p)))
67 #define __get_user(x,p) __get_user_nocheck((x),(p),sizeof(*(p)))
68 #define __get_user_error(x,p,e) __get_user_nocheck_error((x),(p),sizeof(*(p)),(e))
69
70 #define put_user(x,p) __put_user_check((__typeof(*(p)))(x),(p),sizeof(*(p)))
71 #define __put_user(x,p) __put_user_nocheck((__typeof(*(p)))(x),(p),sizeof(*(p)))
72 #define __put_user_error(x,p,e) __put_user_nocheck_error((x),(p),sizeof(*(p)),(e))
73
74 static __inline__ unsigned long copy_from_user(void *to, const void *from, unsigned long n)
75 {
76 if (access_ok(VERIFY_READ, from, n))
77 __do_copy_from_user(to, from, n);
78 return n;
79 }
80
81 static __inline__ unsigned long __copy_from_user(void *to, const void *from, unsigned long n)
82 {
83 __do_copy_from_user(to, from, n);
84 return n;
85 }
86
87 static __inline__ unsigned long copy_to_user(void *to, const void *from, unsigned long n)
88 {
89 if (access_ok(VERIFY_WRITE, to, n))
90 __do_copy_to_user(to, from, n);
91 return n;
92 }
93
94 static __inline__ unsigned long __copy_to_user(void *to, const void *from, unsigned long n)
95 {
96 __do_copy_to_user(to, from, n);
97 return n;
98 }
99
100 static __inline__ unsigned long clear_user (void *to, unsigned long n)
101 {
102 if (access_ok(VERIFY_WRITE, to, n))
103 __do_clear_user(to, n);
104 return n;
105 }
106
107 static __inline__ unsigned long __clear_user (void *to, unsigned long n)
108 {
109 __do_clear_user(to, n);
110 return n;
111 }
112
113 static __inline__ long strncpy_from_user (char *dst, const char *src, long count)
114 {
115 long res = -EFAULT;
116 if (access_ok(VERIFY_READ, src, 1))
117 __do_strncpy_from_user(dst, src, count, res);
118 return res;
119 }
120
121 static __inline__ long __strncpy_from_user (char *dst, const char *src, long count)
122 {
123 long res;
124 __do_strncpy_from_user(dst, src, count, res);
125 return res;
126 }
127
128 #define strlen_user(s) strnlen_user(s, ~0UL >> 1)
129
130 extern __inline__ long strnlen_user(const char *s, long n)
131 {
132 unsigned long res = 0;
133
134 if (__addr_ok(s))
135 __do_strnlen_user(s, n, res);
136
137 return res;
138 }
139
140 /*
141 * These are the work horses of the get/put_user functions
142 */
143 #define __get_user_check(x,ptr,size) \
144 ({ \
145 long __gu_err = -EFAULT, __gu_val = 0; \
146 const __typeof__(*(ptr)) *__gu_addr = (ptr); \
147 if (access_ok(VERIFY_READ,__gu_addr,size)) { \
148 __gu_err = 0; \
149 __get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
150 } \
151 (x) = (__typeof__(*(ptr)))__gu_val; \
152 __gu_err; \
153 })
154
155 #define __get_user_nocheck(x,ptr,size) \
156 ({ \
157 long __gu_err = 0, __gu_val; \
158 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
159 (x) = (__typeof__(*(ptr)))__gu_val; \
160 __gu_err; \
161 })
162
163 #define __get_user_nocheck_error(x,ptr,size,err) \
164 ({ \
165 long __gu_val; \
166 __get_user_size(__gu_val,(ptr),(size),(err)); \
167 (x) = (__typeof__(*(ptr)))__gu_val; \
168 (void) 0; \
169 })
170
171 #define __put_user_check(x,ptr,size) \
172 ({ \
173 long __pu_err = -EFAULT; \
174 __typeof__(*(ptr)) *__pu_addr = (ptr); \
175 if (access_ok(VERIFY_WRITE,__pu_addr,size)) { \
176 __pu_err = 0; \
177 __put_user_size((x),__pu_addr,(size),__pu_err); \
178 } \
179 __pu_err; \
180 })
181
182 #define __put_user_nocheck(x,ptr,size) \
183 ({ \
184 long __pu_err = 0; \
185 __put_user_size((x),(ptr),(size),__pu_err); \
186 __pu_err; \
187 })
188
189 #define __put_user_nocheck_error(x,ptr,size,err) \
190 ({ \
191 __put_user_size((x),(ptr),(size),err); \
192 (void) 0; \
193 })
194
195 extern long __get_user_bad(void);
196
197 #define __get_user_size(x,ptr,size,retval) \
198 do { \
199 switch (size) { \
200 case 1: __get_user_asm_byte(x,ptr,retval); break; \
201 case 2: __get_user_asm_half(x,ptr,retval); break; \
202 case 4: __get_user_asm_word(x,ptr,retval); break; \
203 default: (x) = __get_user_bad(); \
204 } \
205 } while (0)
206
207 extern long __put_user_bad(void);
208
209 #define __put_user_size(x,ptr,size,retval) \
210 do { \
211 switch (size) { \
212 case 1: __put_user_asm_byte(x,ptr,retval); break; \
213 case 2: __put_user_asm_half(x,ptr,retval); break; \
214 case 4: __put_user_asm_word(x,ptr,retval); break; \
215 default: __put_user_bad(); \
216 } \
217 } while (0)
218
219 #endif /* _ASMARM_UACCESS_H */
220
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