1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * OpenRISC Linux
4 *
5 * Linux architectural port borrowing liberally from similar works of
6 * others. All original copyrights apply as per the original source
7 * declaration.
8 *
9 * OpenRISC implementation:
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 * et al.
13 */
14
15 #ifndef __ASM_OPENRISC_UACCESS_H
16 #define __ASM_OPENRISC_UACCESS_H
17
18 /*
19 * User space memory access functions
20 */
21 #include <linux/prefetch.h>
22 #include <linux/string.h>
23 #include <asm/page.h>
24 #include <asm/extable.h>
25 #include <asm-generic/access_ok.h>
26
27 /*
28 * These are the main single-value transfer routines. They automatically
29 * use the right size if we just have the right pointer type.
30 *
31 * This gets kind of ugly. We want to return _two_ values in "get_user()"
32 * and yet we don't want to do any pointers, because that is too much
33 * of a performance impact. Thus we have a few rather ugly macros here,
34 * and hide all the uglyness from the user.
35 *
36 * The "__xxx" versions of the user access functions are versions that
37 * do not verify the address space, that must have been done previously
38 * with a separate "access_ok()" call (this is used when we do multiple
39 * accesses to the same area of user memory).
40 *
41 * As we use the same address space for kernel and user data on the
42 * PowerPC, we can just do these as direct assignments. (Of course, the
43 * exception handling means that it's no longer "just"...)
44 */
45 #define get_user(x, ptr) \
46 __get_user_check((x), (ptr), sizeof(*(ptr)))
47 #define put_user(x, ptr) \
48 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
49
50 #define __get_user(x, ptr) \
51 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
52 #define __put_user(x, ptr) \
53 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
54
55 extern long __put_user_bad(void);
56
57 #define __put_user_nocheck(x, ptr, size) \
58 ({ \
59 long __pu_err; \
60 __put_user_size((x), (ptr), (size), __pu_err); \
61 __pu_err; \
62 })
63
64 #define __put_user_check(x, ptr, size) \
65 ({ \
66 long __pu_err = -EFAULT; \
67 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
68 if (access_ok(__pu_addr, size)) \
69 __put_user_size((x), __pu_addr, (size), __pu_err); \
70 __pu_err; \
71 })
72
73 #define __put_user_size(x, ptr, size, retval) \
74 do { \
75 retval = 0; \
76 switch (size) { \
77 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
78 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
79 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
80 case 8: __put_user_asm2(x, ptr, retval); break; \
81 default: __put_user_bad(); \
82 } \
83 } while (0)
84
85 struct __large_struct {
86 unsigned long buf[100];
87 };
88 #define __m(x) (*(struct __large_struct *)(x))
89
90 /*
91 * We don't tell gcc that we are accessing memory, but this is OK
92 * because we do not write to any memory gcc knows about, so there
93 * are no aliasing issues.
94 */
95 #define __put_user_asm(x, addr, err, op) \
96 __asm__ __volatile__( \
97 "1: "op" 0(%2),%1\n" \
98 "2:\n" \
99 ".section .fixup,\"ax\"\n" \
100 "3: l.addi %0,r0,%3\n" \
101 " l.j 2b\n" \
102 " l.nop\n" \
103 ".previous\n" \
104 ".section __ex_table,\"a\"\n" \
105 " .align 2\n" \
106 " .long 1b,3b\n" \
107 ".previous" \
108 : "=r"(err) \
109 : "r"(x), "r"(addr), "i"(-EFAULT), ""(err))
110
111 #define __put_user_asm2(x, addr, err) \
112 __asm__ __volatile__( \
113 "1: l.sw 0(%2),%1\n" \
114 "2: l.sw 4(%2),%H1\n" \
115 "3:\n" \
116 ".section .fixup,\"ax\"\n" \
117 "4: l.addi %0,r0,%3\n" \
118 " l.j 3b\n" \
119 " l.nop\n" \
120 ".previous\n" \
121 ".section __ex_table,\"a\"\n" \
122 " .align 2\n" \
123 " .long 1b,4b\n" \
124 " .long 2b,4b\n" \
125 ".previous" \
126 : "=r"(err) \
127 : "r"(x), "r"(addr), "i"(-EFAULT), ""(err))
128
129 #define __get_user_nocheck(x, ptr, size) \
130 ({ \
131 long __gu_err; \
132 __get_user_size((x), (ptr), (size), __gu_err); \
133 __gu_err; \
134 })
135
136 #define __get_user_check(x, ptr, size) \
137 ({ \
138 long __gu_err = -EFAULT; \
139 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
140 if (access_ok(__gu_addr, size)) \
141 __get_user_size((x), __gu_addr, (size), __gu_err); \
142 else \
143 (x) = (__typeof__(*(ptr))) 0; \
144 __gu_err; \
145 })
146
147 extern long __get_user_bad(void);
148
149 #define __get_user_size(x, ptr, size, retval) \
150 do { \
151 retval = 0; \
152 switch (size) { \
153 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
154 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
155 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
156 case 8: __get_user_asm2(x, ptr, retval); break; \
157 default: (x) = (__typeof__(*(ptr)))__get_user_bad(); \
158 } \
159 } while (0)
160
161 #define __get_user_asm(x, addr, err, op) \
162 { \
163 unsigned long __gu_tmp; \
164 __asm__ __volatile__( \
165 "1: "op" %1,0(%2)\n" \
166 "2:\n" \
167 ".section .fixup,\"ax\"\n" \
168 "3: l.addi %0,r0,%3\n" \
169 " l.addi %1,r0,0\n" \
170 " l.j 2b\n" \
171 " l.nop\n" \
172 ".previous\n" \
173 ".section __ex_table,\"a\"\n" \
174 " .align 2\n" \
175 " .long 1b,3b\n" \
176 ".previous" \
177 : "=r"(err), "=r"(__gu_tmp) \
178 : "r"(addr), "i"(-EFAULT), ""(err)); \
179 (x) = (__typeof__(*(addr)))__gu_tmp; \
180 }
181
182 #define __get_user_asm2(x, addr, err) \
183 { \
184 unsigned long long __gu_tmp; \
185 __asm__ __volatile__( \
186 "1: l.lwz %1,0(%2)\n" \
187 "2: l.lwz %H1,4(%2)\n" \
188 "3:\n" \
189 ".section .fixup,\"ax\"\n" \
190 "4: l.addi %0,r0,%3\n" \
191 " l.addi %1,r0,0\n" \
192 " l.addi %H1,r0,0\n" \
193 " l.j 3b\n" \
194 " l.nop\n" \
195 ".previous\n" \
196 ".section __ex_table,\"a\"\n" \
197 " .align 2\n" \
198 " .long 1b,4b\n" \
199 " .long 2b,4b\n" \
200 ".previous" \
201 : "=r"(err), "=&r"(__gu_tmp) \
202 : "r"(addr), "i"(-EFAULT), ""(err)); \
203 (x) = (__typeof__(*(addr)))( \
204 (__typeof__((x)-(x)))__gu_tmp); \
205 }
206
207 /* more complex routines */
208
209 extern unsigned long __must_check
210 __copy_tofrom_user(void *to, const void *from, unsigned long size);
211 static inline unsigned long
212 raw_copy_from_user(void *to, const void __user *from, unsigned long size)
213 {
214 return __copy_tofrom_user(to, (__force const void *)from, size);
215 }
216 static inline unsigned long
217 raw_copy_to_user(void __user *to, const void *from, unsigned long size)
218 {
219 return __copy_tofrom_user((__force void *)to, from, size);
220 }
221 #define INLINE_COPY_FROM_USER
222 #define INLINE_COPY_TO_USER
223
224 extern unsigned long __clear_user(void __user *addr, unsigned long size);
225
226 static inline __must_check unsigned long
227 clear_user(void __user *addr, unsigned long size)
228 {
229 if (likely(access_ok(addr, size)))
230 size = __clear_user(addr, size);
231 return size;
232 }
233
234 extern long strncpy_from_user(char *dest, const char __user *src, long count);
235
236 extern __must_check long strnlen_user(const char __user *str, long n);
237
238 #endif /* __ASM_OPENRISC_UACCESS_H */
239
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