Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: e935318804f8aedb6319c4f63f89e5bf8a46c5b0 (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
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_UACCESS_H
#define __ASM_GENERIC_UACCESS_H

/*
 * User space memory access functions, these should work
 * on any machine that has kernel and user data in the same
 * address space, e.g. all NOMMU machines.
 */
#include <linux/string.h>

#ifdef CONFIG_UACCESS_MEMCPY
static inline __must_check unsigned long
raw_copy_from_user(void *to, const void __user * from, unsigned long n)
{
	if (__builtin_constant_p(n)) {
		switch(n) {
		case 1:
			*(u8 *)to = *(u8 __force *)from;
			return 0;
		case 2:
			*(u16 *)to = *(u16 __force *)from;
			return 0;
		case 4:
			*(u32 *)to = *(u32 __force *)from;
			return 0;
#ifdef CONFIG_64BIT
		case 8:
			*(u64 *)to = *(u64 __force *)from;
			return 0;
#endif
		}
	}

	memcpy(to, (const void __force *)from, n);
	return 0;
}

static inline __must_check unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
	if (__builtin_constant_p(n)) {
		switch(n) {
		case 1:
			*(u8 __force *)to = *(u8 *)from;
			return 0;
		case 2:
			*(u16 __force *)to = *(u16 *)from;
			return 0;
		case 4:
			*(u32 __force *)to = *(u32 *)from;
			return 0;
#ifdef CONFIG_64BIT
		case 8:
			*(u64 __force *)to = *(u64 *)from;
			return 0;
#endif
		default:
			break;
		}
	}

	memcpy((void __force *)to, from, n);
	return 0;
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
#endif /* CONFIG_UACCESS_MEMCPY */

#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })

#ifndef KERNEL_DS
#define KERNEL_DS	MAKE_MM_SEG(~0UL)
#endif

#ifndef USER_DS
#define USER_DS		MAKE_MM_SEG(TASK_SIZE - 1)
#endif

#ifndef get_fs
#define get_fs()	(current_thread_info()->addr_limit)

static inline void set_fs(mm_segment_t fs)
{
	current_thread_info()->addr_limit = fs;
}
#endif

#ifndef segment_eq
#define segment_eq(a, b) ((a).seg == (b).seg)
#endif

#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))

/*
 * The architecture should really override this if possible, at least
 * doing a check on the get_fs()
 */
#ifndef __access_ok
static inline int __access_ok(unsigned long addr, unsigned long size)
{
	return 1;
}
#endif

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 * This version just falls back to copy_{from,to}_user, which should
 * provide a fast-path for small values.
 */
#define __put_user(x, ptr) \
({								\
	__typeof__(*(ptr)) __x = (x);				\
	int __pu_err = -EFAULT;					\
        __chk_user_ptr(ptr);                                    \
	switch (sizeof (*(ptr))) {				\
	case 1:							\
	case 2:							\
	case 4:							\
	case 8:							\
		__pu_err = __put_user_fn(sizeof (*(ptr)),	\
					 ptr, &__x);		\
		break;						\
	default:						\
		__put_user_bad();				\
		break;						\
	 }							\
	__pu_err;						\
})

#define put_user(x, ptr)					\
({								\
	void __user *__p = (ptr);				\
	might_fault();						\
	access_ok(__p, sizeof(*ptr)) ?		\
		__put_user((x), ((__typeof__(*(ptr)) __user *)__p)) :	\
		-EFAULT;					\
})

#ifndef __put_user_fn

static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{
	return unlikely(raw_copy_to_user(ptr, x, size)) ? -EFAULT : 0;
}

#define __put_user_fn(sz, u, k)	__put_user_fn(sz, u, k)

#endif

extern int __put_user_bad(void) __attribute__((noreturn));

#define __get_user(x, ptr)					\
({								\
	int __gu_err = -EFAULT;					\
	__chk_user_ptr(ptr);					\
	switch (sizeof(*(ptr))) {				\
	case 1: {						\
		unsigned char __x = 0;				\
		__gu_err = __get_user_fn(sizeof (*(ptr)),	\
					 ptr, &__x);		\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	case 2: {						\
		unsigned short __x = 0;				\
		__gu_err = __get_user_fn(sizeof (*(ptr)),	\
					 ptr, &__x);		\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	case 4: {						\
		unsigned int __x = 0;				\
		__gu_err = __get_user_fn(sizeof (*(ptr)),	\
					 ptr, &__x);		\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	case 8: {						\
		unsigned long long __x = 0;			\
		__gu_err = __get_user_fn(sizeof (*(ptr)),	\
					 ptr, &__x);		\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	default:						\
		__get_user_bad();				\
		break;						\
	}							\
	__gu_err;						\
})

#define get_user(x, ptr)					\
({								\
	const void __user *__p = (ptr);				\
	might_fault();						\
	access_ok(__p, sizeof(*ptr)) ?		\
		__get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
		((x) = (__typeof__(*(ptr)))0,-EFAULT);		\
})

#ifndef __get_user_fn
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
	return unlikely(raw_copy_from_user(x, ptr, size)) ? -EFAULT : 0;
}

#define __get_user_fn(sz, u, k)	__get_user_fn(sz, u, k)

#endif

extern int __get_user_bad(void) __attribute__((noreturn));

/*
 * Copy a null terminated string from userspace.
 */
#ifndef __strncpy_from_user
static inline long
__strncpy_from_user(char *dst, const char __user *src, long count)
{
	char *tmp;
	strncpy(dst, (const char __force *)src, count);
	for (tmp = dst; *tmp && count > 0; tmp++, count--)
		;
	return (tmp - dst);
}
#endif

static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
	if (!access_ok(src, 1))
		return -EFAULT;
	return __strncpy_from_user(dst, src, count);
}

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 on exception, a value greater than N if too long
 */
#ifndef __strnlen_user
#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
#endif

/*
 * Unlike strnlen, strnlen_user includes the nul terminator in
 * its returned count. Callers should check for a returned value
 * greater than N as an indication the string is too long.
 */
static inline long strnlen_user(const char __user *src, long n)
{
	if (!access_ok(src, 1))
		return 0;
	return __strnlen_user(src, n);
}

/*
 * Zero Userspace
 */
#ifndef __clear_user
static inline __must_check unsigned long
__clear_user(void __user *to, unsigned long n)
{
	memset((void __force *)to, 0, n);
	return 0;
}
#endif

static inline __must_check unsigned long
clear_user(void __user *to, unsigned long n)
{
	might_fault();
	if (!access_ok(to, n))
		return n;

	return __clear_user(to, n);
}

#include <asm/extable.h>

#endif /* __ASM_GENERIC_UACCESS_H */