1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ALPHA_UACCESS_H
3 #define __ALPHA_UACCESS_H
4
5 #include <asm-generic/access_ok.h>
6 /*
7 * These are the main single-value transfer routines. They automatically
8 * use the right size if we just have the right pointer type.
9 *
10 * As the alpha uses the same address space for kernel and user
11 * data, we can just do these as direct assignments. (Of course, the
12 * exception handling means that it's no longer "just"...)
13 *
14 * Careful to not
15 * (a) re-use the arguments for side effects (sizeof/typeof is ok)
16 * (b) require any knowledge of processes at this stage
17 */
18 #define put_user(x, ptr) \
19 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
20 #define get_user(x, ptr) \
21 __get_user_check((x), (ptr), sizeof(*(ptr)))
22
23 /*
24 * The "__xxx" versions do not do address space checking, useful when
25 * doing multiple accesses to the same area (the programmer has to do the
26 * checks by hand with "access_ok()")
27 */
28 #define __put_user(x, ptr) \
29 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
30 #define __get_user(x, ptr) \
31 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
32
33 /*
34 * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
35 * encode the bits we need for resolving the exception. See the
36 * more extensive comments with fixup_inline_exception below for
37 * more information.
38 */
39 #define EXC(label,cont,res,err) \
40 ".section __ex_table,\"a\"\n" \
41 " .long "#label"-.\n" \
42 " lda "#res","#cont"-"#label"("#err")\n" \
43 ".previous\n"
44
45 extern void __get_user_unknown(void);
46
47 #define __get_user_nocheck(x, ptr, size) \
48 ({ \
49 long __gu_err = 0; \
50 unsigned long __gu_val; \
51 __chk_user_ptr(ptr); \
52 switch (size) { \
53 case 1: __get_user_8(ptr); break; \
54 case 2: __get_user_16(ptr); break; \
55 case 4: __get_user_32(ptr); break; \
56 case 8: __get_user_64(ptr); break; \
57 default: __get_user_unknown(); break; \
58 } \
59 (x) = (__force __typeof__(*(ptr))) __gu_val; \
60 __gu_err; \
61 })
62
63 #define __get_user_check(x, ptr, size) \
64 ({ \
65 long __gu_err = -EFAULT; \
66 unsigned long __gu_val = 0; \
67 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
68 if (__access_ok(__gu_addr, size)) { \
69 __gu_err = 0; \
70 switch (size) { \
71 case 1: __get_user_8(__gu_addr); break; \
72 case 2: __get_user_16(__gu_addr); break; \
73 case 4: __get_user_32(__gu_addr); break; \
74 case 8: __get_user_64(__gu_addr); break; \
75 default: __get_user_unknown(); break; \
76 } \
77 } \
78 (x) = (__force __typeof__(*(ptr))) __gu_val; \
79 __gu_err; \
80 })
81
82 struct __large_struct { unsigned long buf[100]; };
83 #define __m(x) (*(struct __large_struct __user *)(x))
84
85 #define __get_user_64(addr) \
86 __asm__("1: ldq %0,%2\n" \
87 "2:\n" \
88 EXC(1b,2b,%0,%1) \
89 : "=r"(__gu_val), "=r"(__gu_err) \
90 : "m"(__m(addr)), "1"(__gu_err))
91
92 #define __get_user_32(addr) \
93 __asm__("1: ldl %0,%2\n" \
94 "2:\n" \
95 EXC(1b,2b,%0,%1) \
96 : "=r"(__gu_val), "=r"(__gu_err) \
97 : "m"(__m(addr)), "1"(__gu_err))
98
99 #define __get_user_16(addr) \
100 __asm__("1: ldwu %0,%2\n" \
101 "2:\n" \
102 EXC(1b,2b,%0,%1) \
103 : "=r"(__gu_val), "=r"(__gu_err) \
104 : "m"(__m(addr)), "1"(__gu_err))
105
106 #define __get_user_8(addr) \
107 __asm__("1: ldbu %0,%2\n" \
108 "2:\n" \
109 EXC(1b,2b,%0,%1) \
110 : "=r"(__gu_val), "=r"(__gu_err) \
111 : "m"(__m(addr)), "1"(__gu_err))
112
113 extern void __put_user_unknown(void);
114
115 #define __put_user_nocheck(x, ptr, size) \
116 ({ \
117 long __pu_err = 0; \
118 __chk_user_ptr(ptr); \
119 switch (size) { \
120 case 1: __put_user_8(x, ptr); break; \
121 case 2: __put_user_16(x, ptr); break; \
122 case 4: __put_user_32(x, ptr); break; \
123 case 8: __put_user_64(x, ptr); break; \
124 default: __put_user_unknown(); break; \
125 } \
126 __pu_err; \
127 })
128
129 #define __put_user_check(x, ptr, size) \
130 ({ \
131 long __pu_err = -EFAULT; \
132 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
133 if (__access_ok(__pu_addr, size)) { \
134 __pu_err = 0; \
135 switch (size) { \
136 case 1: __put_user_8(x, __pu_addr); break; \
137 case 2: __put_user_16(x, __pu_addr); break; \
138 case 4: __put_user_32(x, __pu_addr); break; \
139 case 8: __put_user_64(x, __pu_addr); break; \
140 default: __put_user_unknown(); break; \
141 } \
142 } \
143 __pu_err; \
144 })
145
146 /*
147 * The "__put_user_xx()" macros tell gcc they read from memory
148 * instead of writing: this is because they do not write to
149 * any memory gcc knows about, so there are no aliasing issues
150 */
151 #define __put_user_64(x, addr) \
152 __asm__ __volatile__("1: stq %r2,%1\n" \
153 "2:\n" \
154 EXC(1b,2b,$31,%0) \
155 : "=r"(__pu_err) \
156 : "m" (__m(addr)), "rJ" (x), ""(__pu_err))
157
158 #define __put_user_32(x, addr) \
159 __asm__ __volatile__("1: stl %r2,%1\n" \
160 "2:\n" \
161 EXC(1b,2b,$31,%0) \
162 : "=r"(__pu_err) \
163 : "m"(__m(addr)), "rJ"(x), ""(__pu_err))
164
165 #define __put_user_16(x, addr) \
166 __asm__ __volatile__("1: stw %r2,%1\n" \
167 "2:\n" \
168 EXC(1b,2b,$31,%0) \
169 : "=r"(__pu_err) \
170 : "m"(__m(addr)), "rJ"(x), ""(__pu_err))
171
172 #define __put_user_8(x, addr) \
173 __asm__ __volatile__("1: stb %r2,%1\n" \
174 "2:\n" \
175 EXC(1b,2b,$31,%0) \
176 : "=r"(__pu_err) \
177 : "m"(__m(addr)), "rJ"(x), ""(__pu_err))
178
179 /*
180 * Complex access routines
181 */
182
183 extern long __copy_user(void *to, const void *from, long len);
184
185 static inline unsigned long
186 raw_copy_from_user(void *to, const void __user *from, unsigned long len)
187 {
188 return __copy_user(to, (__force const void *)from, len);
189 }
190
191 static inline unsigned long
192 raw_copy_to_user(void __user *to, const void *from, unsigned long len)
193 {
194 return __copy_user((__force void *)to, from, len);
195 }
196
197 extern long __clear_user(void __user *to, long len);
198
199 static inline long
200 clear_user(void __user *to, long len)
201 {
202 if (__access_ok(to, len))
203 len = __clear_user(to, len);
204 return len;
205 }
206
207 extern long strncpy_from_user(char *dest, const char __user *src, long count);
208 extern __must_check long strnlen_user(const char __user *str, long n);
209
210 #include <asm/extable.h>
211
212 #endif /* __ALPHA_UACCESS_H */
213
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