arch/x86/include/asm/uaccess_64.h

   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
  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
  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
 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
 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
 191 static inline int
 192 __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
 193 {
 194         might_sleep();
 195         return __copy_user_nocache(dst, src, size, 1);
 196 }
 197
 198 static inline int
 199 __copy_from_user_inatomic_nocache(void *dst, 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 */