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
|
/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2005-2017 Andes Technology Corporation
#ifndef _ASMANDES_UACCESS_H
#define _ASMANDES_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/types.h>
#define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t"
/*
* 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);
#define KERNEL_DS ((mm_segment_t) { ~0UL })
#define USER_DS ((mm_segment_t) {TASK_SIZE - 1})
#define get_fs() (current_thread_info()->addr_limit)
#define user_addr_max get_fs
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
}
#define uaccess_kernel() (get_fs() == KERNEL_DS)
#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))
#define access_ok(addr, size) \
__range_ok((unsigned long)addr, (unsigned long)size)
/*
* 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).
*/
#define get_user __get_user \
#define __get_user(x, ptr) \
({ \
long __gu_err = 0; \
__get_user_check((x), (ptr), __gu_err); \
__gu_err; \
})
#define __get_user_error(x, ptr, err) \
({ \
__get_user_check((x), (ptr), (err)); \
(void)0; \
})
#define __get_user_check(x, ptr, err) \
({ \
const __typeof__(*(ptr)) __user *__p = (ptr); \
might_fault(); \
if (access_ok(__p, sizeof(*__p))) { \
__get_user_err((x), __p, (err)); \
} else { \
(x) = 0; (err) = -EFAULT; \
} \
})
#define __get_user_err(x, ptr, err) \
do { \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("lbi", __gu_val, (ptr), (err)); \
break; \
case 2: \
__get_user_asm("lhi", __gu_val, (ptr), (err)); \
break; \
case 4: \
__get_user_asm("lwi", __gu_val, (ptr), (err)); \
break; \
case 8: \
__get_user_asm_dword(__gu_val, (ptr), (err)); \
break; \
default: \
BUILD_BUG(); \
break; \
} \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
} while (0)
#define __get_user_asm(inst, x, addr, err) \
__asm__ __volatile__ ( \
"1: "inst" %1,[%2]\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: move %0, %3\n" \
" move %1, #0\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT) \
: "cc")
#ifdef __NDS32_EB__
#define __gu_reg_oper0 "%H1"
#define __gu_reg_oper1 "%L1"
#else
#define __gu_reg_oper0 "%L1"
#define __gu_reg_oper1 "%H1"
#endif
#define __get_user_asm_dword(x, addr, err) \
__asm__ __volatile__ ( \
"\n1:\tlwi " __gu_reg_oper0 ",[%2]\n" \
"\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n" \
"3:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"4: move %0, %3\n" \
" b 3b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .previous" \
: "+r"(err), "=&r"(x) \
: "r"(addr), "i"(-EFAULT) \
: "cc")
#define put_user __put_user \
#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_check(x, ptr, err) \
({ \
__typeof__(*(ptr)) __user *__p = (ptr); \
might_fault(); \
if (access_ok(__p, sizeof(*__p))) { \
__put_user_err((x), __p, (err)); \
} else { \
(err) = -EFAULT; \
} \
})
#define __put_user_err(x, ptr, err) \
do { \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
__put_user_asm("sbi", __pu_val, (ptr), (err)); \
break; \
case 2: \
__put_user_asm("shi", __pu_val, (ptr), (err)); \
break; \
case 4: \
__put_user_asm("swi", __pu_val, (ptr), (err)); \
break; \
case 8: \
__put_user_asm_dword(__pu_val, (ptr), (err)); \
break; \
default: \
BUILD_BUG(); \
break; \
} \
} while (0)
#define __put_user_asm(inst, x, addr, err) \
__asm__ __volatile__ ( \
"1: "inst" %1,[%2]\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: move %0, %3\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT) \
: "cc")
#ifdef __NDS32_EB__
#define __pu_reg_oper0 "%H2"
#define __pu_reg_oper1 "%L2"
#else
#define __pu_reg_oper0 "%L2"
#define __pu_reg_oper1 "%H2"
#endif
#define __put_user_asm_dword(x, addr, err) \
__asm__ __volatile__ ( \
"\n1:\tswi " __pu_reg_oper0 ",[%1]\n" \
"\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n" \
"3:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"4: move %0, %3\n" \
" b 3b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .previous" \
: "+r"(err) \
: "r"(addr), "r"(x), "i"(-EFAULT) \
: "cc")
extern unsigned long __arch_clear_user(void __user * addr, unsigned long n);
extern long strncpy_from_user(char *dest, const char __user * src, long count);
extern __must_check long strnlen_user(const char __user * str, long n);
extern unsigned long __arch_copy_from_user(void *to, const void __user * from,
unsigned long n);
extern unsigned long __arch_copy_to_user(void __user * to, const void *from,
unsigned long n);
#define raw_copy_from_user __arch_copy_from_user
#define raw_copy_to_user __arch_copy_to_user
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
static inline unsigned long clear_user(void __user * to, unsigned long n)
{
if (access_ok(to, n))
n = __arch_clear_user(to, n);
return n;
}
static inline unsigned long __clear_user(void __user * to, unsigned long n)
{
return __arch_clear_user(to, n);
}
#endif /* _ASMNDS32_UACCESS_H */
|
