summaryrefslogtreecommitdiffstats
path: root/include/asm-arm26/uaccess.h
blob: ab9ce38c6aec994875f9a39ce8bfa63612b8388f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
#ifndef _ASMARM_UACCESS_H
#define _ASMARM_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/sched.h>
#include <asm/errno.h>

#define VERIFY_READ 0
#define VERIFY_WRITE 1

/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry
{
	unsigned long insn, fixup;
};

/* Returns 0 if exception not found and fixup otherwise.  */
extern unsigned long search_exception_table(unsigned long);
extern int fixup_exception(struct pt_regs *regs);

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current_thread_info()->addr_limit)
#define segment_eq(a,b)	((a) == (b))

#include <asm/uaccess-asm.h>

#define access_ok(type,addr,size)	(__range_ok(addr,size) == 0)

/* this function will go away soon - use access_ok() instead */
static inline int __deprecated verify_area(int type, const void * addr, unsigned long size)
{
	return access_ok(type, addr, size) ? 0 : -EFAULT;
}

/*
 * Single-value transfer routines.  They automatically use the right
 * size if we just have the right pointer type.  Note that the functions
 * which read from user space (*get_*) need to take care not to leak
 * kernel data even if the calling code is buggy and fails to check
 * the return value.  This means zeroing out the destination variable
 * or buffer on error.  Normally this is done out of line by the
 * fixup code, but there are a few places where it intrudes on the
 * main code path.  When we only write to user space, there is no
 * problem.
 *
 * The "__xxx" versions of the user access functions do not verify the
 * address space - it must have been done previously with a separate
 * "access_ok()" call.
 *
 * The "xxx_error" versions set the third argument to EFAULT if an
 * error occurs, and leave it unchanged on success.  Note that these
 * versions are void (ie, don't return a value as such).
 */

extern int __get_user_1(void *);
extern int __get_user_2(void *);
extern int __get_user_4(void *);
extern int __get_user_8(void *);
extern int __get_user_bad(void);

#define __get_user_x(__r1,__p,__e,__s,__i...)				\
	   __asm__ __volatile__ ("bl	__get_user_" #__s		\
		: "=&r" (__e), "=r" (__r1)				\
		: "0" (__p)						\
		: __i)

#define get_user(x,p)							\
	({								\
		const register typeof(*(p)) *__p asm("r0") = (p);	\
		register typeof(*(p)) __r1 asm("r1");			\
		register int __e asm("r0");				\
		switch (sizeof(*(p))) {					\
		case 1:							\
			__get_user_x(__r1, __p, __e, 1, "lr");		\
	       		break;						\
		case 2:							\
			__get_user_x(__r1, __p, __e, 2, "r2", "lr");	\
			break;						\
		case 4:							\
	       		__get_user_x(__r1, __p, __e, 4, "lr");		\
			break;						\
		case 8:							\
			__get_user_x(__r1, __p, __e, 8, "lr");		\
	       		break;						\
		default: __e = __get_user_bad(); break;			\
		}							\
		x = __r1;						\
		__e;							\
	})


#define __get_user(x,ptr)                                               \
({                                                                      \
        long __gu_err = 0;                                              \
        __get_user_err((x),(ptr),__gu_err);                             \
        __gu_err;                                                       \
})

#define __get_user_error(x,ptr,err)                                     \
({                                                                      \
        __get_user_err((x),(ptr),err);                                  \
        (void) 0;                                                       \
})

#define __get_user_err(x,ptr,err)                                       \
do {                                                                    \
        unsigned long __gu_addr = (unsigned long)(ptr);                 \
        unsigned long __gu_val;                                         \
        switch (sizeof(*(ptr))) {                                       \
        case 1: __get_user_asm_byte(__gu_val,__gu_addr,err);    break;  \
        case 2: __get_user_asm_half(__gu_val,__gu_addr,err);    break;  \
        case 4: __get_user_asm_word(__gu_val,__gu_addr,err);    break;  \
        default: (__gu_val) = __get_user_bad();                         \
        }                                                               \
        (x) = (__typeof__(*(ptr)))__gu_val;                             \
} while (0)

extern int __put_user_1(void *, unsigned int);
extern int __put_user_2(void *, unsigned int);
extern int __put_user_4(void *, unsigned int);
extern int __put_user_8(void *, unsigned long long);
extern int __put_user_bad(void);

#define __put_user_x(__r1,__p,__e,__s)                                  \
           __asm__ __volatile__ (                                       \
                __asmeq("%0", "r0") __asmeq("%2", "r1")                 \
                "bl     __put_user_" #__s                               \
                : "=&r" (__e)                                           \
                : "0" (__p), "r" (__r1)                                 \
                : "ip", "lr", "cc")

#define put_user(x,p)                                                   \
        ({                                                              \
                const register typeof(*(p)) __r1 asm("r1") = (x);       \
                const register typeof(*(p)) *__p asm("r0") = (p);       \
                register int __e asm("r0");                             \
                switch (sizeof(*(__p))) {                               \
                case 1:                                                 \
                        __put_user_x(__r1, __p, __e, 1);                \
                        break;                                          \
                case 2:                                                 \
                        __put_user_x(__r1, __p, __e, 2);                \
                        break;                                          \
                case 4:                                                 \
                        __put_user_x(__r1, __p, __e, 4);                \
                        break;                                          \
                case 8:                                                 \
                        __put_user_x(__r1, __p, __e, 8);                \
                        break;                                          \
                default: __e = __put_user_bad(); break;                 \
                }                                                       \
                __e;                                                    \
        })

#if 0
/*********************   OLD METHOD *******************/
#define __put_user_x(__r1,__p,__e,__s,__i...)				\
	   __asm__ __volatile__ ("bl	__put_user_" #__s		\
		: "=&r" (__e)						\
		: "0" (__p), "r" (__r1)					\
		: __i)

#define put_user(x,p)							\
	({								\
		const register typeof(*(p)) __r1 asm("r1") = (x);	\
		const register typeof(*(p)) *__p asm("r0") = (p);	\
		register int __e asm("r0");				\
		switch (sizeof(*(p))) {					\
		case 1:							\
			__put_user_x(__r1, __p, __e, 1, "r2", "lr");	\
			break;						\
		case 2:							\
			__put_user_x(__r1, __p, __e, 2, "r2", "lr");	\
			break;						\
		case 4:							\
			__put_user_x(__r1, __p, __e, 4, "r2", "lr");	\
			break;						\
		case 8:							\
			__put_user_x(__r1, __p, __e, 8, "r2", "ip", "lr");	\
			break;						\
		default: __e = __put_user_bad(); break;			\
		}							\
		__e;							\
	})
/*************************************************/
#endif

#define __put_user(x,ptr)                                               \
({                                                                      \
        long __pu_err = 0;                                              \
        __put_user_err((x),(ptr),__pu_err);                             \
        __pu_err;                                                       \
})

#define __put_user_error(x,ptr,err)                                     \
({                                                                      \
        __put_user_err((x),(ptr),err);                                  \
        (void) 0;                                                       \
})

#define __put_user_err(x,ptr,err)                                       \
do {                                                                    \
        unsigned long __pu_addr = (unsigned long)(ptr);                 \
        __typeof__(*(ptr)) __pu_val = (x);                              \
        switch (sizeof(*(ptr))) {                                       \
        case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);    break;  \
        case 2: __put_user_asm_half(__pu_val,__pu_addr,err);    break;  \
        case 4: __put_user_asm_word(__pu_val,__pu_addr,err);    break;  \
        case 8: __put_user_asm_dword(__pu_val,__pu_addr,err);   break;  \
        default: __put_user_bad();                                      \
        }                                                               \
} while (0)

static __inline__ unsigned long copy_from_user(void *to, const void *from, unsigned long n)
{
	if (access_ok(VERIFY_READ, from, n))
		__do_copy_from_user(to, from, n);
	else /* security hole - plug it */
		memzero(to, n);
	return n;
}

static __inline__ unsigned long __copy_from_user(void *to, const void *from, unsigned long n)
{
	__do_copy_from_user(to, from, n);
	return n;
}

static __inline__ unsigned long copy_to_user(void *to, const void *from, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		__do_copy_to_user(to, from, n);
	return n;
}

static __inline__ unsigned long __copy_to_user(void *to, const void *from, unsigned long n)
{
	__do_copy_to_user(to, from, n);
	return n;
}

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

static __inline__ unsigned long clear_user (void *to, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		__do_clear_user(to, n);
	return n;
}

static __inline__ unsigned long __clear_user (void *to, unsigned long n)
{
	__do_clear_user(to, n);
	return n;
}

static __inline__ long strncpy_from_user (char *dst, const char *src, long count)
{
	long res = -EFAULT;
	if (access_ok(VERIFY_READ, src, 1))
		__do_strncpy_from_user(dst, src, count, res);
	return res;
}

static __inline__ long __strncpy_from_user (char *dst, const char *src, long count)
{
	long res;
	__do_strncpy_from_user(dst, src, count, res);
	return res;
}

#define strlen_user(s)	strnlen_user(s, ~0UL >> 1)

static inline long strnlen_user(const char *s, long n)
{
	unsigned long res = 0;

	if (__addr_ok(s))
		__do_strnlen_user(s, n, res);

	return res;
}

#endif /* _ASMARM_UACCESS_H */
OpenPOWER on IntegriCloud