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
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		register const 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                register const typeof(*(p)) __r1 asm("r1") = (x);       \
143                register const 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
164#define __put_user(x,ptr)                                               \
165({                                                                      \
166        long __pu_err = 0;                                              \
167        __put_user_err((x),(ptr),__pu_err);                             \
168        __pu_err;                                                       \
169})
170
171#define __put_user_error(x,ptr,err)                                     \
172({                                                                      \
173        __put_user_err((x),(ptr),err);                                  \
174        (void) 0;                                                       \
175})
176
177#define __put_user_err(x,ptr,err)                                       \
178do {                                                                    \
179        unsigned long __pu_addr = (unsigned long)(ptr);                 \
180        __typeof__(*(ptr)) __pu_val = (x);                              \
181        switch (sizeof(*(ptr))) {                                       \
182        case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);    break;  \
183        case 2: __put_user_asm_half(__pu_val,__pu_addr,err);    break;  \
184        case 4: __put_user_asm_word(__pu_val,__pu_addr,err);    break;  \
185        case 8: __put_user_asm_dword(__pu_val,__pu_addr,err);   break;  \
186        default: __put_user_bad();                                      \
187        }                                                               \
188} while (0)
189
190static __inline__ unsigned long copy_from_user(void *to, const void *from, unsigned long n)
191{
192	if (access_ok(VERIFY_READ, from, n))
193		__do_copy_from_user(to, from, n);
194	else /* security hole - plug it */
195		memzero(to, n);
196	return n;
197}
198
199static __inline__ unsigned long __copy_from_user(void *to, const void *from, unsigned long n)
200{
201	__do_copy_from_user(to, from, n);
202	return n;
203}
204
205static __inline__ unsigned long copy_to_user(void *to, const void *from, unsigned long n)
206{
207	if (access_ok(VERIFY_WRITE, to, n))
208		__do_copy_to_user(to, from, n);
209	return n;
210}
211
212static __inline__ unsigned long __copy_to_user(void *to, const void *from, unsigned long n)
213{
214	__do_copy_to_user(to, from, n);
215	return n;
216}
217
218#define __copy_to_user_inatomic __copy_to_user
219#define __copy_from_user_inatomic __copy_from_user
220
221static __inline__ unsigned long clear_user (void *to, unsigned long n)
222{
223	if (access_ok(VERIFY_WRITE, to, n))
224		__do_clear_user(to, n);
225	return n;
226}
227
228static __inline__ unsigned long __clear_user (void *to, unsigned long n)
229{
230	__do_clear_user(to, n);
231	return n;
232}
233
234static __inline__ long strncpy_from_user (char *dst, const char *src, long count)
235{
236	long res = -EFAULT;
237	if (access_ok(VERIFY_READ, src, 1))
238		__do_strncpy_from_user(dst, src, count, res);
239	return res;
240}
241
242static __inline__ long __strncpy_from_user (char *dst, const char *src, long count)
243{
244	long res;
245	__do_strncpy_from_user(dst, src, count, res);
246	return res;
247}
248
249#define strlen_user(s)	strnlen_user(s, ~0UL >> 1)
250
251static inline long strnlen_user(const char *s, long n)
252{
253	unsigned long res = 0;
254
255	if (__addr_ok(s))
256		__do_strnlen_user(s, n, res);
257
258	return res;
259}
260
261#endif /* _ASMARM_UACCESS_H */
262