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gerrit-public.fairphone.software / kernel / msm-4.9 / 2c23d62abb820e19c54012520f08a198c2233a85 / . / include / asm-arm26 / uaccess.h
blob: 3f2dd1093e58b6a233c20f223043f7efaa8afc13 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
26struct exception_table_entry
27{
28 unsigned long insn, fixup;
29};
30
31/* Returns 0 if exception not found and fixup otherwise. */
32extern unsigned long search_exception_table(unsigned long);
33extern 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
63extern int __get_user_1(void *);
64extern int __get_user_2(void *);
65extern int __get_user_4(void *);
66extern int __get_user_8(void *);
67extern 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) \
114do { \
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
126extern int __put_user_1(void *, unsigned int);
127extern int __put_user_2(void *, unsigned int);
128extern int __put_user_4(void *, unsigned int);
129extern int __put_user_8(void *, unsigned long long);
130extern 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) \
210do { \
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
222static __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
231static __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
237static __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
244static __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
253static __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
260static __inline__ unsigned long __clear_user (void *to, unsigned long n)
261{
262 __do_clear_user(to, n);
263 return n;
264}
265
266static __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
274static __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
283static 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 */