[PATCH] Kexec / Kdump: Unify elf note code
[linux-2.6.git] / include / asm-arm26 / uaccess.h
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 extern int fixup_exception(struct pt_regs *regs);
34
35 #define get_ds()        (KERNEL_DS)
36 #define get_fs()        (current_thread_info()->addr_limit)
37 #define segment_eq(a,b) ((a) == (b))
38
39 #include <asm/uaccess-asm.h>
40
41 #define access_ok(type,addr,size)       (__range_ok(addr,size) == 0)
42
43 /*
44  * Single-value transfer routines.  They automatically use the right
45  * size if we just have the right pointer type.  Note that the functions
46  * which read from user space (*get_*) need to take care not to leak
47  * kernel data even if the calling code is buggy and fails to check
48  * the return value.  This means zeroing out the destination variable
49  * or buffer on error.  Normally this is done out of line by the
50  * fixup code, but there are a few places where it intrudes on the
51  * main code path.  When we only write to user space, there is no
52  * problem.
53  *
54  * The "__xxx" versions of the user access functions do not verify the
55  * address space - it must have been done previously with a separate
56  * "access_ok()" call.
57  *
58  * The "xxx_error" versions set the third argument to EFAULT if an
59  * error occurs, and leave it unchanged on success.  Note that these
60  * versions are void (ie, don't return a value as such).
61  */
62
63 extern int __get_user_1(void *);
64 extern int __get_user_2(void *);
65 extern int __get_user_4(void *);
66 extern int __get_user_8(void *);
67 extern int __get_user_bad(void);
68
69 #define __get_user_x(__r1,__p,__e,__s,__i...)                           \
70            __asm__ __volatile__ ("bl    __get_user_" #__s               \
71                 : "=&r" (__e), "=r" (__r1)                              \
72                 : "0" (__p)                                             \
73                 : __i)
74
75 #define get_user(x,p)                                                   \
76         ({                                                              \
77                 const register typeof(*(p)) *__p asm("r0") = (p);       \
78                 register typeof(*(p)) __r1 asm("r1");                   \
79                 register int __e asm("r0");                             \
80                 switch (sizeof(*(p))) {                                 \
81                 case 1:                                                 \
82                         __get_user_x(__r1, __p, __e, 1, "lr");          \
83                         break;                                          \
84                 case 2:                                                 \
85                         __get_user_x(__r1, __p, __e, 2, "r2", "lr");    \
86                         break;                                          \
87                 case 4:                                                 \
88                         __get_user_x(__r1, __p, __e, 4, "lr");          \
89                         break;                                          \
90                 case 8:                                                 \
91                         __get_user_x(__r1, __p, __e, 8, "lr");          \
92                         break;                                          \
93                 default: __e = __get_user_bad(); break;                 \
94                 }                                                       \
95                 x = __r1;                                               \
96                 __e;                                                    \
97         })
98
99
100 #define __get_user(x,ptr)                                               \
101 ({                                                                      \
102         long __gu_err = 0;                                              \
103         __get_user_err((x),(ptr),__gu_err);                             \
104         __gu_err;                                                       \
105 })
106
107 #define __get_user_error(x,ptr,err)                                     \
108 ({                                                                      \
109         __get_user_err((x),(ptr),err);                                  \
110         (void) 0;                                                       \
111 })
112
113 #define __get_user_err(x,ptr,err)                                       \
114 do {                                                                    \
115         unsigned long __gu_addr = (unsigned long)(ptr);                 \
116         unsigned long __gu_val;                                         \
117         switch (sizeof(*(ptr))) {                                       \
118         case 1: __get_user_asm_byte(__gu_val,__gu_addr,err);    break;  \
119         case 2: __get_user_asm_half(__gu_val,__gu_addr,err);    break;  \
120         case 4: __get_user_asm_word(__gu_val,__gu_addr,err);    break;  \
121         default: (__gu_val) = __get_user_bad();                         \
122         }                                                               \
123         (x) = (__typeof__(*(ptr)))__gu_val;                             \
124 } while (0)
125
126 extern int __put_user_1(void *, unsigned int);
127 extern int __put_user_2(void *, unsigned int);
128 extern int __put_user_4(void *, unsigned int);
129 extern int __put_user_8(void *, unsigned long long);
130 extern int __put_user_bad(void);
131
132 #define __put_user_x(__r1,__p,__e,__s)                                  \
133            __asm__ __volatile__ (                                       \
134                 __asmeq("%0", "r0") __asmeq("%2", "r1")                 \
135                 "bl     __put_user_" #__s                               \
136                 : "=&r" (__e)                                           \
137                 : "0" (__p), "r" (__r1)                                 \
138                 : "ip", "lr", "cc")
139
140 #define put_user(x,p)                                                   \
141         ({                                                              \
142                 const register typeof(*(p)) __r1 asm("r1") = (x);       \
143                 const register typeof(*(p)) *__p asm("r0") = (p);       \
144                 register int __e asm("r0");                             \
145                 switch (sizeof(*(__p))) {                               \
146                 case 1:                                                 \
147                         __put_user_x(__r1, __p, __e, 1);                \
148                         break;                                          \
149                 case 2:                                                 \
150                         __put_user_x(__r1, __p, __e, 2);                \
151                         break;                                          \
152                 case 4:                                                 \
153                         __put_user_x(__r1, __p, __e, 4);                \
154                         break;                                          \
155                 case 8:                                                 \
156                         __put_user_x(__r1, __p, __e, 8);                \
157                         break;                                          \
158                 default: __e = __put_user_bad(); break;                 \
159                 }                                                       \
160                 __e;                                                    \
161         })
162
163 #if 0
164 /*********************   OLD METHOD *******************/
165 #define __put_user_x(__r1,__p,__e,__s,__i...)                           \
166            __asm__ __volatile__ ("bl    __put_user_" #__s               \
167                 : "=&r" (__e)                                           \
168                 : "0" (__p), "r" (__r1)                                 \
169                 : __i)
170
171 #define put_user(x,p)                                                   \
172         ({                                                              \
173                 const register typeof(*(p)) __r1 asm("r1") = (x);       \
174                 const register typeof(*(p)) *__p asm("r0") = (p);       \
175                 register int __e asm("r0");                             \
176                 switch (sizeof(*(p))) {                                 \
177                 case 1:                                                 \
178                         __put_user_x(__r1, __p, __e, 1, "r2", "lr");    \
179                         break;                                          \
180                 case 2:                                                 \
181                         __put_user_x(__r1, __p, __e, 2, "r2", "lr");    \
182                         break;                                          \
183                 case 4:                                                 \
184                         __put_user_x(__r1, __p, __e, 4, "r2", "lr");    \
185                         break;                                          \
186                 case 8:                                                 \
187                         __put_user_x(__r1, __p, __e, 8, "r2", "ip", "lr");      \
188                         break;                                          \
189                 default: __e = __put_user_bad(); break;                 \
190                 }                                                       \
191                 __e;                                                    \
192         })
193 /*************************************************/
194 #endif
195
196 #define __put_user(x,ptr)                                               \
197 ({                                                                      \
198         long __pu_err = 0;                                              \
199         __put_user_err((x),(ptr),__pu_err);                             \
200         __pu_err;                                                       \
201 })
202
203 #define __put_user_error(x,ptr,err)                                     \
204 ({                                                                      \
205         __put_user_err((x),(ptr),err);                                  \
206         (void) 0;                                                       \
207 })
208
209 #define __put_user_err(x,ptr,err)                                       \
210 do {                                                                    \
211         unsigned long __pu_addr = (unsigned long)(ptr);                 \
212         __typeof__(*(ptr)) __pu_val = (x);                              \
213         switch (sizeof(*(ptr))) {                                       \
214         case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);    break;  \
215         case 2: __put_user_asm_half(__pu_val,__pu_addr,err);    break;  \
216         case 4: __put_user_asm_word(__pu_val,__pu_addr,err);    break;  \
217         case 8: __put_user_asm_dword(__pu_val,__pu_addr,err);   break;  \
218         default: __put_user_bad();                                      \
219         }                                                               \
220 } while (0)
221
222 static __inline__ unsigned long copy_from_user(void *to, const void *from, unsigned long n)
223 {
224         if (access_ok(VERIFY_READ, from, n))
225                 __do_copy_from_user(to, from, n);
226         else /* security hole - plug it */
227                 memzero(to, n);
228         return n;
229 }
230
231 static __inline__ unsigned long __copy_from_user(void *to, const void *from, unsigned long n)
232 {
233         __do_copy_from_user(to, from, n);
234         return n;
235 }
236
237 static __inline__ unsigned long copy_to_user(void *to, const void *from, unsigned long n)
238 {
239         if (access_ok(VERIFY_WRITE, to, n))
240                 __do_copy_to_user(to, from, n);
241         return n;
242 }
243
244 static __inline__ unsigned long __copy_to_user(void *to, const void *from, unsigned long n)
245 {
246         __do_copy_to_user(to, from, n);
247         return n;
248 }
249
250 #define __copy_to_user_inatomic __copy_to_user
251 #define __copy_from_user_inatomic __copy_from_user
252
253 static __inline__ unsigned long clear_user (void *to, unsigned long n)
254 {
255         if (access_ok(VERIFY_WRITE, to, n))
256                 __do_clear_user(to, n);
257         return n;
258 }
259
260 static __inline__ unsigned long __clear_user (void *to, unsigned long n)
261 {
262         __do_clear_user(to, n);
263         return n;
264 }
265
266 static __inline__ long strncpy_from_user (char *dst, const char *src, long count)
267 {
268         long res = -EFAULT;
269         if (access_ok(VERIFY_READ, src, 1))
270                 __do_strncpy_from_user(dst, src, count, res);
271         return res;
272 }
273
274 static __inline__ long __strncpy_from_user (char *dst, const char *src, long count)
275 {
276         long res;
277         __do_strncpy_from_user(dst, src, count, res);
278         return res;
279 }
280
281 #define strlen_user(s)  strnlen_user(s, ~0UL >> 1)
282
283 static inline long strnlen_user(const char *s, long n)
284 {
285         unsigned long res = 0;
286
287         if (__addr_ok(s))
288                 __do_strnlen_user(s, n, res);
289
290         return res;
291 }
292
293 #endif /* _ASMARM_UACCESS_H */