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1 #ifndef _ASM_X86_UACCESS_64_H
2 #define _ASM_X86_UACCESS_64_H
3 
4 /*
5  * User space memory access functions
6  */
7 #include <linux/compiler.h>
8 #include <linux/errno.h>
9 #include <linux/prefetch.h>
10 #include <linux/lockdep.h>
11 #include <asm/page.h>
12 
13 /*
14  * Copy To/From Userspace
15  */
16 
17 /* Handles exceptions in both to and from, but doesn't do access_ok */
18 __must_check unsigned long
19 copy_user_generic(void *to, const void *from, unsigned len);
20 
21 __must_check unsigned long
22 copy_to_user(void __user *to, const void *from, unsigned len);
23 __must_check unsigned long
24 copy_from_user(void *to, const void __user *from, unsigned len);
25 __must_check unsigned long
26 copy_in_user(void __user *to, const void __user *from, unsigned len);
27 
28 static __always_inline __must_check
__copy_from_user(void * dst,const void __user * src,unsigned size)29 int __copy_from_user(void *dst, const void __user *src, unsigned size)
30 {
31 	int ret = 0;
32 
33 	might_fault();
34 	if (!__builtin_constant_p(size))
35 		return copy_user_generic(dst, (__force void *)src, size);
36 	switch (size) {
37 	case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
38 			      ret, "b", "b", "=q", 1);
39 		return ret;
40 	case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
41 			      ret, "w", "w", "=r", 2);
42 		return ret;
43 	case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
44 			      ret, "l", "k", "=r", 4);
45 		return ret;
46 	case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
47 			      ret, "q", "", "=r", 8);
48 		return ret;
49 	case 10:
50 		__get_user_asm(*(u64 *)dst, (u64 __user *)src,
51 			       ret, "q", "", "=r", 10);
52 		if (unlikely(ret))
53 			return ret;
54 		__get_user_asm(*(u16 *)(8 + (char *)dst),
55 			       (u16 __user *)(8 + (char __user *)src),
56 			       ret, "w", "w", "=r", 2);
57 		return ret;
58 	case 16:
59 		__get_user_asm(*(u64 *)dst, (u64 __user *)src,
60 			       ret, "q", "", "=r", 16);
61 		if (unlikely(ret))
62 			return ret;
63 		__get_user_asm(*(u64 *)(8 + (char *)dst),
64 			       (u64 __user *)(8 + (char __user *)src),
65 			       ret, "q", "", "=r", 8);
66 		return ret;
67 	default:
68 		return copy_user_generic(dst, (__force void *)src, size);
69 	}
70 }
71 
72 static __always_inline __must_check
__copy_to_user(void __user * dst,const void * src,unsigned size)73 int __copy_to_user(void __user *dst, const void *src, unsigned size)
74 {
75 	int ret = 0;
76 
77 	might_fault();
78 	if (!__builtin_constant_p(size))
79 		return copy_user_generic((__force void *)dst, src, size);
80 	switch (size) {
81 	case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
82 			      ret, "b", "b", "iq", 1);
83 		return ret;
84 	case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
85 			      ret, "w", "w", "ir", 2);
86 		return ret;
87 	case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
88 			      ret, "l", "k", "ir", 4);
89 		return ret;
90 	case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
91 			      ret, "q", "", "ir", 8);
92 		return ret;
93 	case 10:
94 		__put_user_asm(*(u64 *)src, (u64 __user *)dst,
95 			       ret, "q", "", "ir", 10);
96 		if (unlikely(ret))
97 			return ret;
98 		asm("":::"memory");
99 		__put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
100 			       ret, "w", "w", "ir", 2);
101 		return ret;
102 	case 16:
103 		__put_user_asm(*(u64 *)src, (u64 __user *)dst,
104 			       ret, "q", "", "ir", 16);
105 		if (unlikely(ret))
106 			return ret;
107 		asm("":::"memory");
108 		__put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
109 			       ret, "q", "", "ir", 8);
110 		return ret;
111 	default:
112 		return copy_user_generic((__force void *)dst, src, size);
113 	}
114 }
115 
116 static __always_inline __must_check
__copy_in_user(void __user * dst,const void __user * src,unsigned size)117 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
118 {
119 	int ret = 0;
120 
121 	might_fault();
122 	if (!__builtin_constant_p(size))
123 		return copy_user_generic((__force void *)dst,
124 					 (__force void *)src, size);
125 	switch (size) {
126 	case 1: {
127 		u8 tmp;
128 		__get_user_asm(tmp, (u8 __user *)src,
129 			       ret, "b", "b", "=q", 1);
130 		if (likely(!ret))
131 			__put_user_asm(tmp, (u8 __user *)dst,
132 				       ret, "b", "b", "iq", 1);
133 		return ret;
134 	}
135 	case 2: {
136 		u16 tmp;
137 		__get_user_asm(tmp, (u16 __user *)src,
138 			       ret, "w", "w", "=r", 2);
139 		if (likely(!ret))
140 			__put_user_asm(tmp, (u16 __user *)dst,
141 				       ret, "w", "w", "ir", 2);
142 		return ret;
143 	}
144 
145 	case 4: {
146 		u32 tmp;
147 		__get_user_asm(tmp, (u32 __user *)src,
148 			       ret, "l", "k", "=r", 4);
149 		if (likely(!ret))
150 			__put_user_asm(tmp, (u32 __user *)dst,
151 				       ret, "l", "k", "ir", 4);
152 		return ret;
153 	}
154 	case 8: {
155 		u64 tmp;
156 		__get_user_asm(tmp, (u64 __user *)src,
157 			       ret, "q", "", "=r", 8);
158 		if (likely(!ret))
159 			__put_user_asm(tmp, (u64 __user *)dst,
160 				       ret, "q", "", "ir", 8);
161 		return ret;
162 	}
163 	default:
164 		return copy_user_generic((__force void *)dst,
165 					 (__force void *)src, size);
166 	}
167 }
168 
169 __must_check long
170 strncpy_from_user(char *dst, const char __user *src, long count);
171 __must_check long
172 __strncpy_from_user(char *dst, const char __user *src, long count);
173 __must_check long strnlen_user(const char __user *str, long n);
174 __must_check long __strnlen_user(const char __user *str, long n);
175 __must_check long strlen_user(const char __user *str);
176 __must_check unsigned long clear_user(void __user *mem, unsigned long len);
177 __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
178 
179 __must_check long __copy_from_user_inatomic(void *dst, const void __user *src,
180 					    unsigned size);
181 
182 static __must_check __always_inline int
__copy_to_user_inatomic(void __user * dst,const void * src,unsigned size)183 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
184 {
185 	return copy_user_generic((__force void *)dst, src, size);
186 }
187 
188 extern long __copy_user_nocache(void *dst, const void __user *src,
189 				unsigned size, int zerorest);
190 
__copy_from_user_nocache(void * dst,const void __user * src,unsigned size)191 static inline int __copy_from_user_nocache(void *dst, const void __user *src,
192 					   unsigned size)
193 {
194 	might_sleep();
195 	return __copy_user_nocache(dst, src, size, 1);
196 }
197 
__copy_from_user_inatomic_nocache(void * dst,const void __user * src,unsigned size)198 static inline int __copy_from_user_inatomic_nocache(void *dst,
199 						    const void __user *src,
200 						    unsigned size)
201 {
202 	return __copy_user_nocache(dst, src, size, 0);
203 }
204 
205 unsigned long
206 copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);
207 
208 #endif /* _ASM_X86_UACCESS_64_H */
209