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
|
#ifndef __METAG_UACCESS_H
#define __METAG_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#define segment_eq(a, b) ((a).seg == (b).seg)
#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
/*
* Explicitly allow NULL pointers here. Parts of the kernel such
* as readv/writev use access_ok to validate pointers, but want
* to allow NULL pointers for various reasons. NULL pointers are
* safe to allow through because the first page is not mappable on
* Meta.
*
* We also wish to avoid letting user code access the system area
* and the kernel half of the address space.
*/
#define __user_bad(addr, size) (((addr) > 0 && (addr) < META_MEMORY_BASE) || \
((addr) > PAGE_OFFSET && \
(addr) < LINCORE_BASE))
static inline int __access_ok(unsigned long addr, unsigned long size)
{
return __kernel_ok || !__user_bad(addr, size);
}
#define access_ok(type, addr, size) __access_ok((unsigned long)(addr), \
(unsigned long)(size))
static inline int verify_area(int type, const void *addr, unsigned long size)
{
return access_ok(type, addr, size) ? 0 : -EFAULT;
}
/*
* 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;
};
extern int fixup_exception(struct pt_regs *regs);
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
#define put_user(x, ptr) \
__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
extern void __put_user_bad(void);
#define __put_user_nocheck(x, ptr, size) \
({ \
long __pu_err; \
__put_user_size((x), (ptr), (size), __pu_err); \
__pu_err; \
})
#define __put_user_check(x, ptr, size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
})
extern long __put_user_asm_b(unsigned int x, void __user *addr);
extern long __put_user_asm_w(unsigned int x, void __user *addr);
extern long __put_user_asm_d(unsigned int x, void __user *addr);
extern long __put_user_asm_l(unsigned long long x, void __user *addr);
#define __put_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
switch (size) { \
case 1: \
retval = __put_user_asm_b((__force unsigned int)x, ptr);\
break; \
case 2: \
retval = __put_user_asm_w((__force unsigned int)x, ptr);\
break; \
case 4: \
retval = __put_user_asm_d((__force unsigned int)x, ptr);\
break; \
case 8: \
retval = __put_user_asm_l((__force unsigned long long)x,\
ptr); \
break; \
default: \
__put_user_bad(); \
} \
} while (0)
#define get_user(x, ptr) \
__get_user_check((x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
extern long __get_user_bad(void);
#define __get_user_nocheck(x, ptr, size) \
({ \
long __gu_err, __gu_val; \
__get_user_size(__gu_val, (ptr), (size), __gu_err); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_check(x, ptr, size) \
({ \
long __gu_err = -EFAULT, __gu_val = 0; \
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
if (access_ok(VERIFY_READ, __gu_addr, size)) \
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
extern unsigned char __get_user_asm_b(const void __user *addr, long *err);
extern unsigned short __get_user_asm_w(const void __user *addr, long *err);
extern unsigned int __get_user_asm_d(const void __user *addr, long *err);
#define __get_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
switch (size) { \
case 1: \
x = __get_user_asm_b(ptr, &retval); break; \
case 2: \
x = __get_user_asm_w(ptr, &retval); break; \
case 4: \
x = __get_user_asm_d(ptr, &retval); break; \
default: \
(x) = __get_user_bad(); \
} \
} while (0)
/*
* Copy a null terminated string from userspace.
*
* Must return:
* -EFAULT for an exception
* count if we hit the buffer limit
* bytes copied if we hit a null byte
* (without the null byte)
*/
extern long __must_check __strncpy_from_user(char *dst, const char __user *src,
long count);
#define strncpy_from_user(dst, src, count) __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
*/
extern long __must_check strnlen_user(const char __user *src, long count);
#define strlen_user(str) strnlen_user(str, 32767)
extern unsigned long raw_copy_from_user(void *to, const void __user *from,
unsigned long n);
static inline unsigned long
copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long res = n;
if (likely(access_ok(VERIFY_READ, from, n)))
res = raw_copy_from_user(to, from, n);
if (unlikely(res))
memset(to + (n - res), 0, res);
return res;
}
#define __copy_from_user(to, from, n) raw_copy_from_user(to, from, n)
#define __copy_from_user_inatomic __copy_from_user
extern unsigned long __must_check __copy_user(void __user *to,
const void *from,
unsigned long n);
static inline unsigned long copy_to_user(void __user *to, const void *from,
unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
return __copy_user(to, from, n);
return n;
}
#define __copy_to_user(to, from, n) __copy_user(to, from, n)
#define __copy_to_user_inatomic __copy_to_user
/*
* Zero Userspace
*/
extern unsigned long __must_check __do_clear_user(void __user *to,
unsigned long n);
static inline unsigned long clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
return __do_clear_user(to, n);
return n;
}
#define __clear_user(to, n) __do_clear_user(to, n)
#endif /* _METAG_UACCESS_H */
|
