1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * uaccess.h: User space memore access functions.
4 *
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7 */
8 #ifndef _ASM_UACCESS_H
9 #define _ASM_UACCESS_H
10
11 #include <linux/compiler.h>
12 #include <linux/string.h>
13
14 #include <asm/processor.h>
15 #include <asm-generic/access_ok.h>
16
17 /* Uh, these should become the main single-value transfer routines..
18 * They automatically use the right size if we just have the right
19 * pointer type..
20 *
21 * This gets kind of ugly. We want to return _two_ values in "get_user()"
22 * and yet we don't want to do any pointers, because that is too much
23 * of a performance impact. Thus we have a few rather ugly macros here,
24 * and hide all the ugliness from the user.
25 */
26 #define put_user(x, ptr) ({ \
27 void __user *__pu_addr = (ptr); \
28 __chk_user_ptr(ptr); \
29 __put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
30 })
31
32 #define get_user(x, ptr) ({ \
33 const void __user *__gu_addr = (ptr); \
34 __chk_user_ptr(ptr); \
35 __get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
36 })
37
38 /*
39 * The "__xxx" versions do not do address space checking, useful when
40 * doing multiple accesses to the same area (the user has to do the
41 * checks by hand with "access_ok()")
42 */
43 #define __put_user(x, ptr) \
44 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
45 #define __get_user(x, ptr) \
46 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), __typeof__(*(ptr)))
47
48 struct __large_struct { unsigned long buf[100]; };
49 #define __m(x) ((struct __large_struct __user *)(x))
50
51 #define __put_user_check(x, addr, size) ({ \
52 register int __pu_ret; \
53 if (__access_ok(addr, size)) { \
54 switch (size) { \
55 case 1: \
56 __put_user_asm(x, b, addr, __pu_ret); \
57 break; \
58 case 2: \
59 __put_user_asm(x, h, addr, __pu_ret); \
60 break; \
61 case 4: \
62 __put_user_asm(x, , addr, __pu_ret); \
63 break; \
64 case 8: \
65 __put_user_asm(x, d, addr, __pu_ret); \
66 break; \
67 default: \
68 __pu_ret = __put_user_bad(); \
69 break; \
70 } \
71 } else { \
72 __pu_ret = -EFAULT; \
73 } \
74 __pu_ret; \
75 })
76
77 #define __put_user_nocheck(x, addr, size) ({ \
78 register int __pu_ret; \
79 switch (size) { \
80 case 1: __put_user_asm(x, b, addr, __pu_ret); break; \
81 case 2: __put_user_asm(x, h, addr, __pu_ret); break; \
82 case 4: __put_user_asm(x, , addr, __pu_ret); break; \
83 case 8: __put_user_asm(x, d, addr, __pu_ret); break; \
84 default: __pu_ret = __put_user_bad(); break; \
85 } \
86 __pu_ret; \
87 })
88
89 #define __put_user_asm(x, size, addr, ret) \
90 __asm__ __volatile__( \
91 "/* Put user asm, inline. */\n" \
92 "1:\t" "st"#size " %1, %2\n\t" \
93 "clr %0\n" \
94 "2:\n\n\t" \
95 ".section .fixup,#alloc,#execinstr\n\t" \
96 ".align 4\n" \
97 "3:\n\t" \
98 "sethi %%hi(2b), %0\n\t" \
99 "jmpl %0 + %%lo(2b), %%g0\n\t" \
100 " mov %3, %0\n\t" \
101 ".previous\n\n\t" \
102 ".section __ex_table,#alloc\n\t" \
103 ".align 4\n\t" \
104 ".word 1b, 3b\n\t" \
105 ".previous\n\n\t" \
106 : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
107 "i" (-EFAULT))
108
109 int __put_user_bad(void);
110
111 #define __get_user_check(x, addr, size, type) ({ \
112 register int __gu_ret; \
113 register unsigned long __gu_val; \
114 if (__access_ok(addr, size)) { \
115 switch (size) { \
116 case 1: \
117 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
118 break; \
119 case 2: \
120 __get_user_asm(__gu_val, uh, addr, __gu_ret); \
121 break; \
122 case 4: \
123 __get_user_asm(__gu_val, , addr, __gu_ret); \
124 break; \
125 case 8: \
126 __get_user_asm(__gu_val, d, addr, __gu_ret); \
127 break; \
128 default: \
129 __gu_val = 0; \
130 __gu_ret = __get_user_bad(); \
131 break; \
132 } \
133 } else { \
134 __gu_val = 0; \
135 __gu_ret = -EFAULT; \
136 } \
137 x = (__force type) __gu_val; \
138 __gu_ret; \
139 })
140
141 #define __get_user_nocheck(x, addr, size, type) ({ \
142 register int __gu_ret; \
143 register unsigned long __gu_val; \
144 switch (size) { \
145 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
146 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
147 case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
148 case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
149 default: \
150 __gu_val = 0; \
151 __gu_ret = __get_user_bad(); \
152 break; \
153 } \
154 x = (__force type) __gu_val; \
155 __gu_ret; \
156 })
157
158 #define __get_user_asm(x, size, addr, ret) \
159 __asm__ __volatile__( \
160 "/* Get user asm, inline. */\n" \
161 "1:\t" "ld"#size " %2, %1\n\t" \
162 "clr %0\n" \
163 "2:\n\n\t" \
164 ".section .fixup,#alloc,#execinstr\n\t" \
165 ".align 4\n" \
166 "3:\n\t" \
167 "sethi %%hi(2b), %0\n\t" \
168 "clr %1\n\t" \
169 "jmpl %0 + %%lo(2b), %%g0\n\t" \
170 " mov %3, %0\n\n\t" \
171 ".previous\n\t" \
172 ".section __ex_table,#alloc\n\t" \
173 ".align 4\n\t" \
174 ".word 1b, 3b\n\n\t" \
175 ".previous\n\t" \
176 : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
177 "i" (-EFAULT))
178
179 int __get_user_bad(void);
180
181 unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
182
183 static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
184 {
185 return __copy_user(to, (__force void __user *) from, n);
186 }
187
188 static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
189 {
190 return __copy_user((__force void __user *) to, from, n);
191 }
192
193 #define INLINE_COPY_FROM_USER
194 #define INLINE_COPY_TO_USER
195
196 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
197 {
198 unsigned long ret;
199
200 __asm__ __volatile__ (
201 "mov %2, %%o1\n"
202 "call __bzero\n\t"
203 " mov %1, %%o0\n\t"
204 "mov %%o0, %0\n"
205 : "=r" (ret) : "r" (addr), "r" (size) :
206 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
207 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
208
209 return ret;
210 }
211
212 static inline unsigned long clear_user(void __user *addr, unsigned long n)
213 {
214 if (n && __access_ok(addr, n))
215 return __clear_user(addr, n);
216 else
217 return n;
218 }
219
220 __must_check long strnlen_user(const char __user *str, long n);
221
222 #endif /* _ASM_UACCESS_H */
223
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