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/lockdep.h> 10 #include <asm/alternative.h> 11 #include <asm/cpufeature.h> 12 #include <asm/page.h> 13 14 /* 15 * Copy To/From Userspace 16 */ 17 18 /* Handles exceptions in both to and from, but doesn't do access_ok */ 19 __must_check unsigned long 20 copy_user_generic_string(void *to, const void *from, unsigned len); 21 __must_check unsigned long 22 copy_user_generic_unrolled(void *to, const void *from, unsigned len); 23 24 static __always_inline __must_check unsigned long 25 copy_user_generic(void *to, const void *from, unsigned len) 26 { 27 unsigned ret; 28 29 alternative_call(copy_user_generic_unrolled, 30 copy_user_generic_string, 31 X86_FEATURE_REP_GOOD, 32 ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from), 33 "=d" (len)), 34 "1" (to), "2" (from), "3" (len) 35 : "memory", "rcx", "r8", "r9", "r10", "r11"); 36 return ret; 37 } 38 39 __must_check unsigned long 40 _copy_to_user(void __user *to, const void *from, unsigned len); 41 __must_check unsigned long 42 _copy_from_user(void *to, const void __user *from, unsigned len); 43 __must_check unsigned long 44 copy_in_user(void __user *to, const void __user *from, unsigned len); 45 46 static inline unsigned long __must_check copy_from_user(void *to, 47 const void __user *from, 48 unsigned long n) 49 { 50 int sz = __compiletime_object_size(to); 51 52 might_fault(); 53 if (likely(sz == -1 || sz >= n)) 54 n = _copy_from_user(to, from, n); 55 #ifdef CONFIG_DEBUG_VM 56 else 57 WARN(1, "Buffer overflow detected!\n"); 58 #endif 59 return n; 60 } 61 62 static __always_inline __must_check 63 int copy_to_user(void __user *dst, const void *src, unsigned size) 64 { 65 might_fault(); 66 67 return _copy_to_user(dst, src, size); 68 } 69 70 static __always_inline __must_check 71 int __copy_from_user(void *dst, const void __user *src, unsigned size) 72 { 73 int ret = 0; 74 75 might_fault(); 76 if (!__builtin_constant_p(size)) 77 return copy_user_generic(dst, (__force void *)src, size); 78 switch (size) { 79 case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src, 80 ret, "b", "b", "=q", 1); 81 return ret; 82 case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src, 83 ret, "w", "w", "=r", 2); 84 return ret; 85 case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src, 86 ret, "l", "k", "=r", 4); 87 return ret; 88 case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src, 89 ret, "q", "", "=r", 8); 90 return ret; 91 case 10: 92 __get_user_asm(*(u64 *)dst, (u64 __user *)src, 93 ret, "q", "", "=r", 10); 94 if (unlikely(ret)) 95 return ret; 96 __get_user_asm(*(u16 *)(8 + (char *)dst), 97 (u16 __user *)(8 + (char __user *)src), 98 ret, "w", "w", "=r", 2); 99 return ret; 100 case 16: 101 __get_user_asm(*(u64 *)dst, (u64 __user *)src, 102 ret, "q", "", "=r", 16); 103 if (unlikely(ret)) 104 return ret; 105 __get_user_asm(*(u64 *)(8 + (char *)dst), 106 (u64 __user *)(8 + (char __user *)src), 107 ret, "q", "", "=r", 8); 108 return ret; 109 default: 110 return copy_user_generic(dst, (__force void *)src, size); 111 } 112 } 113 114 static __always_inline __must_check 115 int __copy_to_user(void __user *dst, const void *src, unsigned size) 116 { 117 int ret = 0; 118 119 might_fault(); 120 if (!__builtin_constant_p(size)) 121 return copy_user_generic((__force void *)dst, src, size); 122 switch (size) { 123 case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst, 124 ret, "b", "b", "iq", 1); 125 return ret; 126 case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst, 127 ret, "w", "w", "ir", 2); 128 return ret; 129 case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst, 130 ret, "l", "k", "ir", 4); 131 return ret; 132 case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst, 133 ret, "q", "", "er", 8); 134 return ret; 135 case 10: 136 __put_user_asm(*(u64 *)src, (u64 __user *)dst, 137 ret, "q", "", "er", 10); 138 if (unlikely(ret)) 139 return ret; 140 asm("":::"memory"); 141 __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst, 142 ret, "w", "w", "ir", 2); 143 return ret; 144 case 16: 145 __put_user_asm(*(u64 *)src, (u64 __user *)dst, 146 ret, "q", "", "er", 16); 147 if (unlikely(ret)) 148 return ret; 149 asm("":::"memory"); 150 __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst, 151 ret, "q", "", "er", 8); 152 return ret; 153 default: 154 return copy_user_generic((__force void *)dst, src, size); 155 } 156 } 157 158 static __always_inline __must_check 159 int __copy_in_user(void __user *dst, const void __user *src, unsigned size) 160 { 161 int ret = 0; 162 163 might_fault(); 164 if (!__builtin_constant_p(size)) 165 return copy_user_generic((__force void *)dst, 166 (__force void *)src, size); 167 switch (size) { 168 case 1: { 169 u8 tmp; 170 __get_user_asm(tmp, (u8 __user *)src, 171 ret, "b", "b", "=q", 1); 172 if (likely(!ret)) 173 __put_user_asm(tmp, (u8 __user *)dst, 174 ret, "b", "b", "iq", 1); 175 return ret; 176 } 177 case 2: { 178 u16 tmp; 179 __get_user_asm(tmp, (u16 __user *)src, 180 ret, "w", "w", "=r", 2); 181 if (likely(!ret)) 182 __put_user_asm(tmp, (u16 __user *)dst, 183 ret, "w", "w", "ir", 2); 184 return ret; 185 } 186 187 case 4: { 188 u32 tmp; 189 __get_user_asm(tmp, (u32 __user *)src, 190 ret, "l", "k", "=r", 4); 191 if (likely(!ret)) 192 __put_user_asm(tmp, (u32 __user *)dst, 193 ret, "l", "k", "ir", 4); 194 return ret; 195 } 196 case 8: { 197 u64 tmp; 198 __get_user_asm(tmp, (u64 __user *)src, 199 ret, "q", "", "=r", 8); 200 if (likely(!ret)) 201 __put_user_asm(tmp, (u64 __user *)dst, 202 ret, "q", "", "er", 8); 203 return ret; 204 } 205 default: 206 return copy_user_generic((__force void *)dst, 207 (__force void *)src, size); 208 } 209 } 210 211 __must_check long 212 strncpy_from_user(char *dst, const char __user *src, long count); 213 __must_check long 214 __strncpy_from_user(char *dst, const char __user *src, long count); 215 __must_check long strnlen_user(const char __user *str, long n); 216 __must_check long __strnlen_user(const char __user *str, long n); 217 __must_check long strlen_user(const char __user *str); 218 __must_check unsigned long clear_user(void __user *mem, unsigned long len); 219 __must_check unsigned long __clear_user(void __user *mem, unsigned long len); 220 221 static __must_check __always_inline int 222 __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size) 223 { 224 return copy_user_generic(dst, (__force const void *)src, size); 225 } 226 227 static __must_check __always_inline int 228 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size) 229 { 230 return copy_user_generic((__force void *)dst, src, size); 231 } 232 233 extern long __copy_user_nocache(void *dst, const void __user *src, 234 unsigned size, int zerorest); 235 236 static inline int 237 __copy_from_user_nocache(void *dst, const void __user *src, unsigned size) 238 { 239 might_sleep(); 240 return __copy_user_nocache(dst, src, size, 1); 241 } 242 243 static inline int 244 __copy_from_user_inatomic_nocache(void *dst, const void __user *src, 245 unsigned size) 246 { 247 return __copy_user_nocache(dst, src, size, 0); 248 } 249 250 unsigned long 251 copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest); 252 253 #endif /* _ASM_X86_UACCESS_64_H */ 254