Loading...
1#ifndef __ASM_GENERIC_UACCESS_H
2#define __ASM_GENERIC_UACCESS_H
3
4/*
5 * User space memory access functions, these should work
6 * on any machine that has kernel and user data in the same
7 * address space, e.g. all NOMMU machines.
8 */
9#include <linux/sched.h>
10#include <linux/string.h>
11
12#include <asm/segment.h>
13
14#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
15
16#ifndef KERNEL_DS
17#define KERNEL_DS MAKE_MM_SEG(~0UL)
18#endif
19
20#ifndef USER_DS
21#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
22#endif
23
24#ifndef get_fs
25#define get_ds() (KERNEL_DS)
26#define get_fs() (current_thread_info()->addr_limit)
27
28static inline void set_fs(mm_segment_t fs)
29{
30 current_thread_info()->addr_limit = fs;
31}
32#endif
33
34#ifndef segment_eq
35#define segment_eq(a, b) ((a).seg == (b).seg)
36#endif
37
38#define VERIFY_READ 0
39#define VERIFY_WRITE 1
40
41#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
42
43/*
44 * The architecture should really override this if possible, at least
45 * doing a check on the get_fs()
46 */
47#ifndef __access_ok
48static inline int __access_ok(unsigned long addr, unsigned long size)
49{
50 return 1;
51}
52#endif
53
54/*
55 * The exception table consists of pairs of addresses: the first is the
56 * address of an instruction that is allowed to fault, and the second is
57 * the address at which the program should continue. No registers are
58 * modified, so it is entirely up to the continuation code to figure out
59 * what to do.
60 *
61 * All the routines below use bits of fixup code that are out of line
62 * with the main instruction path. This means when everything is well,
63 * we don't even have to jump over them. Further, they do not intrude
64 * on our cache or tlb entries.
65 */
66
67struct exception_table_entry
68{
69 unsigned long insn, fixup;
70};
71
72/*
73 * architectures with an MMU should override these two
74 */
75#ifndef __copy_from_user
76static inline __must_check long __copy_from_user(void *to,
77 const void __user * from, unsigned long n)
78{
79 if (__builtin_constant_p(n)) {
80 switch(n) {
81 case 1:
82 *(u8 *)to = *(u8 __force *)from;
83 return 0;
84 case 2:
85 *(u16 *)to = *(u16 __force *)from;
86 return 0;
87 case 4:
88 *(u32 *)to = *(u32 __force *)from;
89 return 0;
90#ifdef CONFIG_64BIT
91 case 8:
92 *(u64 *)to = *(u64 __force *)from;
93 return 0;
94#endif
95 default:
96 break;
97 }
98 }
99
100 memcpy(to, (const void __force *)from, n);
101 return 0;
102}
103#endif
104
105#ifndef __copy_to_user
106static inline __must_check long __copy_to_user(void __user *to,
107 const void *from, unsigned long n)
108{
109 if (__builtin_constant_p(n)) {
110 switch(n) {
111 case 1:
112 *(u8 __force *)to = *(u8 *)from;
113 return 0;
114 case 2:
115 *(u16 __force *)to = *(u16 *)from;
116 return 0;
117 case 4:
118 *(u32 __force *)to = *(u32 *)from;
119 return 0;
120#ifdef CONFIG_64BIT
121 case 8:
122 *(u64 __force *)to = *(u64 *)from;
123 return 0;
124#endif
125 default:
126 break;
127 }
128 }
129
130 memcpy((void __force *)to, from, n);
131 return 0;
132}
133#endif
134
135/*
136 * These are the main single-value transfer routines. They automatically
137 * use the right size if we just have the right pointer type.
138 * This version just falls back to copy_{from,to}_user, which should
139 * provide a fast-path for small values.
140 */
141#define __put_user(x, ptr) \
142({ \
143 __typeof__(*(ptr)) __x = (x); \
144 int __pu_err = -EFAULT; \
145 __chk_user_ptr(ptr); \
146 switch (sizeof (*(ptr))) { \
147 case 1: \
148 case 2: \
149 case 4: \
150 case 8: \
151 __pu_err = __put_user_fn(sizeof (*(ptr)), \
152 ptr, &__x); \
153 break; \
154 default: \
155 __put_user_bad(); \
156 break; \
157 } \
158 __pu_err; \
159})
160
161#define put_user(x, ptr) \
162({ \
163 void *__p = (ptr); \
164 might_fault(); \
165 access_ok(VERIFY_WRITE, __p, sizeof(*ptr)) ? \
166 __put_user((x), ((__typeof__(*(ptr)) *)__p)) : \
167 -EFAULT; \
168})
169
170#ifndef __put_user_fn
171
172static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
173{
174 size = __copy_to_user(ptr, x, size);
175 return size ? -EFAULT : size;
176}
177
178#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
179
180#endif
181
182extern int __put_user_bad(void) __attribute__((noreturn));
183
184#define __get_user(x, ptr) \
185({ \
186 int __gu_err = -EFAULT; \
187 __chk_user_ptr(ptr); \
188 switch (sizeof(*(ptr))) { \
189 case 1: { \
190 unsigned char __x; \
191 __gu_err = __get_user_fn(sizeof (*(ptr)), \
192 ptr, &__x); \
193 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
194 break; \
195 }; \
196 case 2: { \
197 unsigned short __x; \
198 __gu_err = __get_user_fn(sizeof (*(ptr)), \
199 ptr, &__x); \
200 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
201 break; \
202 }; \
203 case 4: { \
204 unsigned int __x; \
205 __gu_err = __get_user_fn(sizeof (*(ptr)), \
206 ptr, &__x); \
207 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
208 break; \
209 }; \
210 case 8: { \
211 unsigned long long __x; \
212 __gu_err = __get_user_fn(sizeof (*(ptr)), \
213 ptr, &__x); \
214 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
215 break; \
216 }; \
217 default: \
218 __get_user_bad(); \
219 break; \
220 } \
221 __gu_err; \
222})
223
224#define get_user(x, ptr) \
225({ \
226 const void *__p = (ptr); \
227 might_fault(); \
228 access_ok(VERIFY_READ, __p, sizeof(*ptr)) ? \
229 __get_user((x), (__typeof__(*(ptr)) *)__p) : \
230 ((x) = (__typeof__(*(ptr)))0,-EFAULT); \
231})
232
233#ifndef __get_user_fn
234static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
235{
236 size_t n = __copy_from_user(x, ptr, size);
237 if (unlikely(n)) {
238 memset(x + (size - n), 0, n);
239 return -EFAULT;
240 }
241 return 0;
242}
243
244#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
245
246#endif
247
248extern int __get_user_bad(void) __attribute__((noreturn));
249
250#ifndef __copy_from_user_inatomic
251#define __copy_from_user_inatomic __copy_from_user
252#endif
253
254#ifndef __copy_to_user_inatomic
255#define __copy_to_user_inatomic __copy_to_user
256#endif
257
258static inline long copy_from_user(void *to,
259 const void __user * from, unsigned long n)
260{
261 unsigned long res = n;
262 might_fault();
263 if (likely(access_ok(VERIFY_READ, from, n)))
264 res = __copy_from_user(to, from, n);
265 if (unlikely(res))
266 memset(to + (n - res), 0, res);
267 return res;
268}
269
270static inline long copy_to_user(void __user *to,
271 const void *from, unsigned long n)
272{
273 might_fault();
274 if (access_ok(VERIFY_WRITE, to, n))
275 return __copy_to_user(to, from, n);
276 else
277 return n;
278}
279
280/*
281 * Copy a null terminated string from userspace.
282 */
283#ifndef __strncpy_from_user
284static inline long
285__strncpy_from_user(char *dst, const char __user *src, long count)
286{
287 char *tmp;
288 strncpy(dst, (const char __force *)src, count);
289 for (tmp = dst; *tmp && count > 0; tmp++, count--)
290 ;
291 return (tmp - dst);
292}
293#endif
294
295static inline long
296strncpy_from_user(char *dst, const char __user *src, long count)
297{
298 if (!access_ok(VERIFY_READ, src, 1))
299 return -EFAULT;
300 return __strncpy_from_user(dst, src, count);
301}
302
303/*
304 * Return the size of a string (including the ending 0)
305 *
306 * Return 0 on exception, a value greater than N if too long
307 */
308#ifndef __strnlen_user
309#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
310#endif
311
312/*
313 * Unlike strnlen, strnlen_user includes the nul terminator in
314 * its returned count. Callers should check for a returned value
315 * greater than N as an indication the string is too long.
316 */
317static inline long strnlen_user(const char __user *src, long n)
318{
319 if (!access_ok(VERIFY_READ, src, 1))
320 return 0;
321 return __strnlen_user(src, n);
322}
323
324static inline long strlen_user(const char __user *src)
325{
326 return strnlen_user(src, 32767);
327}
328
329/*
330 * Zero Userspace
331 */
332#ifndef __clear_user
333static inline __must_check unsigned long
334__clear_user(void __user *to, unsigned long n)
335{
336 memset((void __force *)to, 0, n);
337 return 0;
338}
339#endif
340
341static inline __must_check unsigned long
342clear_user(void __user *to, unsigned long n)
343{
344 might_fault();
345 if (!access_ok(VERIFY_WRITE, to, n))
346 return n;
347
348 return __clear_user(to, n);
349}
350
351#endif /* __ASM_GENERIC_UACCESS_H */
1#ifndef __ASM_GENERIC_UACCESS_H
2#define __ASM_GENERIC_UACCESS_H
3
4/*
5 * User space memory access functions, these should work
6 * on a ny machine that has kernel and user data in the same
7 * address space, e.g. all NOMMU machines.
8 */
9#include <linux/sched.h>
10#include <linux/mm.h>
11#include <linux/string.h>
12
13#include <asm/segment.h>
14
15#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
16
17#ifndef KERNEL_DS
18#define KERNEL_DS MAKE_MM_SEG(~0UL)
19#endif
20
21#ifndef USER_DS
22#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
23#endif
24
25#ifndef get_fs
26#define get_ds() (KERNEL_DS)
27#define get_fs() (current_thread_info()->addr_limit)
28
29static inline void set_fs(mm_segment_t fs)
30{
31 current_thread_info()->addr_limit = fs;
32}
33#endif
34
35#define segment_eq(a, b) ((a).seg == (b).seg)
36
37#define VERIFY_READ 0
38#define VERIFY_WRITE 1
39
40#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
41
42/*
43 * The architecture should really override this if possible, at least
44 * doing a check on the get_fs()
45 */
46#ifndef __access_ok
47static inline int __access_ok(unsigned long addr, unsigned long size)
48{
49 return 1;
50}
51#endif
52
53/*
54 * The exception table consists of pairs of addresses: the first is the
55 * address of an instruction that is allowed to fault, and the second is
56 * the address at which the program should continue. No registers are
57 * modified, so it is entirely up to the continuation code to figure out
58 * what to do.
59 *
60 * All the routines below use bits of fixup code that are out of line
61 * with the main instruction path. This means when everything is well,
62 * we don't even have to jump over them. Further, they do not intrude
63 * on our cache or tlb entries.
64 */
65
66struct exception_table_entry
67{
68 unsigned long insn, fixup;
69};
70
71/* Returns 0 if exception not found and fixup otherwise. */
72extern unsigned long search_exception_table(unsigned long);
73
74/*
75 * architectures with an MMU should override these two
76 */
77#ifndef __copy_from_user
78static inline __must_check long __copy_from_user(void *to,
79 const void __user * from, unsigned long n)
80{
81 if (__builtin_constant_p(n)) {
82 switch(n) {
83 case 1:
84 *(u8 *)to = *(u8 __force *)from;
85 return 0;
86 case 2:
87 *(u16 *)to = *(u16 __force *)from;
88 return 0;
89 case 4:
90 *(u32 *)to = *(u32 __force *)from;
91 return 0;
92#ifdef CONFIG_64BIT
93 case 8:
94 *(u64 *)to = *(u64 __force *)from;
95 return 0;
96#endif
97 default:
98 break;
99 }
100 }
101
102 memcpy(to, (const void __force *)from, n);
103 return 0;
104}
105#endif
106
107#ifndef __copy_to_user
108static inline __must_check long __copy_to_user(void __user *to,
109 const void *from, unsigned long n)
110{
111 if (__builtin_constant_p(n)) {
112 switch(n) {
113 case 1:
114 *(u8 __force *)to = *(u8 *)from;
115 return 0;
116 case 2:
117 *(u16 __force *)to = *(u16 *)from;
118 return 0;
119 case 4:
120 *(u32 __force *)to = *(u32 *)from;
121 return 0;
122#ifdef CONFIG_64BIT
123 case 8:
124 *(u64 __force *)to = *(u64 *)from;
125 return 0;
126#endif
127 default:
128 break;
129 }
130 }
131
132 memcpy((void __force *)to, from, n);
133 return 0;
134}
135#endif
136
137/*
138 * These are the main single-value transfer routines. They automatically
139 * use the right size if we just have the right pointer type.
140 * This version just falls back to copy_{from,to}_user, which should
141 * provide a fast-path for small values.
142 */
143#define __put_user(x, ptr) \
144({ \
145 __typeof__(*(ptr)) __x = (x); \
146 int __pu_err = -EFAULT; \
147 __chk_user_ptr(ptr); \
148 switch (sizeof (*(ptr))) { \
149 case 1: \
150 case 2: \
151 case 4: \
152 case 8: \
153 __pu_err = __put_user_fn(sizeof (*(ptr)), \
154 ptr, &__x); \
155 break; \
156 default: \
157 __put_user_bad(); \
158 break; \
159 } \
160 __pu_err; \
161})
162
163#define put_user(x, ptr) \
164({ \
165 might_sleep(); \
166 access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \
167 __put_user(x, ptr) : \
168 -EFAULT; \
169})
170
171static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
172{
173 size = __copy_to_user(ptr, x, size);
174 return size ? -EFAULT : size;
175}
176
177extern int __put_user_bad(void) __attribute__((noreturn));
178
179#define __get_user(x, ptr) \
180({ \
181 int __gu_err = -EFAULT; \
182 __chk_user_ptr(ptr); \
183 switch (sizeof(*(ptr))) { \
184 case 1: { \
185 unsigned char __x; \
186 __gu_err = __get_user_fn(sizeof (*(ptr)), \
187 ptr, &__x); \
188 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
189 break; \
190 }; \
191 case 2: { \
192 unsigned short __x; \
193 __gu_err = __get_user_fn(sizeof (*(ptr)), \
194 ptr, &__x); \
195 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
196 break; \
197 }; \
198 case 4: { \
199 unsigned int __x; \
200 __gu_err = __get_user_fn(sizeof (*(ptr)), \
201 ptr, &__x); \
202 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
203 break; \
204 }; \
205 case 8: { \
206 unsigned long long __x; \
207 __gu_err = __get_user_fn(sizeof (*(ptr)), \
208 ptr, &__x); \
209 (x) = *(__force __typeof__(*(ptr)) *) &__x; \
210 break; \
211 }; \
212 default: \
213 __get_user_bad(); \
214 break; \
215 } \
216 __gu_err; \
217})
218
219#define get_user(x, ptr) \
220({ \
221 might_sleep(); \
222 access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \
223 __get_user(x, ptr) : \
224 -EFAULT; \
225})
226
227static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
228{
229 size = __copy_from_user(x, ptr, size);
230 return size ? -EFAULT : size;
231}
232
233extern int __get_user_bad(void) __attribute__((noreturn));
234
235#ifndef __copy_from_user_inatomic
236#define __copy_from_user_inatomic __copy_from_user
237#endif
238
239#ifndef __copy_to_user_inatomic
240#define __copy_to_user_inatomic __copy_to_user
241#endif
242
243static inline long copy_from_user(void *to,
244 const void __user * from, unsigned long n)
245{
246 might_sleep();
247 if (access_ok(VERIFY_READ, from, n))
248 return __copy_from_user(to, from, n);
249 else
250 return n;
251}
252
253static inline long copy_to_user(void __user *to,
254 const void *from, unsigned long n)
255{
256 might_sleep();
257 if (access_ok(VERIFY_WRITE, to, n))
258 return __copy_to_user(to, from, n);
259 else
260 return n;
261}
262
263/*
264 * Copy a null terminated string from userspace.
265 */
266#ifndef __strncpy_from_user
267static inline long
268__strncpy_from_user(char *dst, const char __user *src, long count)
269{
270 char *tmp;
271 strncpy(dst, (const char __force *)src, count);
272 for (tmp = dst; *tmp && count > 0; tmp++, count--)
273 ;
274 return (tmp - dst);
275}
276#endif
277
278static inline long
279strncpy_from_user(char *dst, const char __user *src, long count)
280{
281 if (!access_ok(VERIFY_READ, src, 1))
282 return -EFAULT;
283 return __strncpy_from_user(dst, src, count);
284}
285
286/*
287 * Return the size of a string (including the ending 0)
288 *
289 * Return 0 on exception, a value greater than N if too long
290 */
291#ifndef __strnlen_user
292#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
293#endif
294
295/*
296 * Unlike strnlen, strnlen_user includes the nul terminator in
297 * its returned count. Callers should check for a returned value
298 * greater than N as an indication the string is too long.
299 */
300static inline long strnlen_user(const char __user *src, long n)
301{
302 if (!access_ok(VERIFY_READ, src, 1))
303 return 0;
304 return __strnlen_user(src, n);
305}
306
307static inline long strlen_user(const char __user *src)
308{
309 return strnlen_user(src, 32767);
310}
311
312/*
313 * Zero Userspace
314 */
315#ifndef __clear_user
316static inline __must_check unsigned long
317__clear_user(void __user *to, unsigned long n)
318{
319 memset((void __force *)to, 0, n);
320 return 0;
321}
322#endif
323
324static inline __must_check unsigned long
325clear_user(void __user *to, unsigned long n)
326{
327 might_sleep();
328 if (!access_ok(VERIFY_WRITE, to, n))
329 return n;
330
331 return __clear_user(to, n);
332}
333
334#endif /* __ASM_GENERIC_UACCESS_H */