1 /* SPDX-License-Identifier: GPL-2.0 */
3 * uaccess.h: User space memore access functions.
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
11 #include <linux/compiler.h>
12 #include <linux/string.h>
14 #include <asm/processor.h>
15 #include <asm-generic/access_ok.h>
17 /* Uh, these should become the main single-value transfer routines..
18 * They automatically use the right size if we just have the right
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.
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))); \
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))); \
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()")
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)))
48 struct __large_struct { unsigned long buf[100]; };
49 #define __m(x) ((struct __large_struct __user *)(x))
51 #define __put_user_check(x, addr, size) ({ \
52 register int __pu_ret; \
53 if (__access_ok(addr, size)) { \
56 __put_user_asm(x, b, addr, __pu_ret); \
59 __put_user_asm(x, h, addr, __pu_ret); \
62 __put_user_asm(x, , addr, __pu_ret); \
65 __put_user_asm(x, d, addr, __pu_ret); \
68 __pu_ret = __put_user_bad(); \
77 #define __put_user_nocheck(x, addr, size) ({ \
78 register int __pu_ret; \
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; \
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" \
95 ".section .fixup,#alloc,#execinstr\n\t" \
101 ".section __ex_table,#alloc\n\t" \
105 : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
108 int __put_user_bad(void);
110 #define __get_user_check(x, addr, size, type) ({ \
111 register int __gu_ret; \
112 register unsigned long __gu_val; \
113 if (__access_ok(addr, size)) { \
116 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
119 __get_user_asm(__gu_val, uh, addr, __gu_ret); \
122 __get_user_asm(__gu_val, , addr, __gu_ret); \
125 __get_user_asm(__gu_val, d, addr, __gu_ret); \
129 __gu_ret = __get_user_bad(); \
134 __gu_ret = -EFAULT; \
136 x = (__force type) __gu_val; \
140 #define __get_user_nocheck(x, addr, size, type) ({ \
141 register int __gu_ret; \
142 register unsigned long __gu_val; \
144 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
145 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
146 case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
147 case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
150 __gu_ret = __get_user_bad(); \
153 x = (__force type) __gu_val; \
157 #define __get_user_asm(x, size, addr, ret) \
158 __asm__ __volatile__( \
159 "/* Get user asm, inline. */\n" \
160 "1:\t" "ld"#size " %2, %1\n\t" \
163 ".section .fixup,#alloc,#execinstr\n\t" \
168 " mov %3, %0\n\n\t" \
170 ".section __ex_table,#alloc\n\t" \
172 ".word 1b, 3b\n\n\t" \
174 : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
177 int __get_user_bad(void);
179 unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
181 static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
183 return __copy_user(to, (__force void __user *) from, n);
186 static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
188 return __copy_user((__force void __user *) to, from, n);
191 #define INLINE_COPY_FROM_USER
192 #define INLINE_COPY_TO_USER
194 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
198 __asm__ __volatile__ (
203 : "=r" (ret) : "r" (addr), "r" (size) :
204 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
205 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
210 static inline unsigned long clear_user(void __user *addr, unsigned long n)
212 if (n && __access_ok(addr, n))
213 return __clear_user(addr, n);
218 __must_check long strnlen_user(const char __user *str, long n);
220 #endif /* _ASM_UACCESS_H */