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 inline unsigned long __must_check copy_from_user(void *to,
  29                                           const void __user *from,
  30                                           unsigned long n)
  31 {
  32         int sz = __compiletime_object_size(to);
  33         int ret = -EFAULT;
  34
  35         if (likely(sz == -1 || sz >= n))
  36                 ret = _copy_from_user(to, from, n);
  37 #ifdef CONFIG_DEBUG_VM
  38         else
  39                 WARN(1, "Buffer overflow detected!\n");
  40 #endif
  41         return ret;
  42 }
  43
  44
  45 static __always_inline __must_check
  46 int __copy_from_user(void *dst, const void __user *src, unsigned size)
  47 {
  48         int ret = 0;
  49
  50         might_fault();
  51         if (!__builtin_constant_p(size))
  52                 return copy_user_generic(dst, (__force void *)src, size);
  53         switch (size) {
  54         case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
  55                               ret, "b", "b", "=q", 1);
  56                 return ret;
  57         case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
  58                               ret, "w", "w", "=r", 2);
  59                 return ret;
  60         case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
  61                               ret, "l", "k", "=r", 4);
  62                 return ret;
  63         case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
  64                               ret, "q", "", "=r", 8);
  65                 return ret;
  66         case 10:
  67                 __get_user_asm(*(u64 *)dst, (u64 __user *)src,
  68                                ret, "q", "", "=r", 10);
  69                 if (unlikely(ret))
  70                         return ret;
  71                 __get_user_asm(*(u16 *)(8 + (char *)dst),
  72                                (u16 __user *)(8 + (char __user *)src),
  73                                ret, "w", "w", "=r", 2);
  74                 return ret;
  75         case 16:
  76                 __get_user_asm(*(u64 *)dst, (u64 __user *)src,
  77                                ret, "q", "", "=r", 16);
  78                 if (unlikely(ret))
  79                         return ret;
  80                 __get_user_asm(*(u64 *)(8 + (char *)dst),
  81                                (u64 __user *)(8 + (char __user *)src),
  82                                ret, "q", "", "=r", 8);
  83                 return ret;
  84         default:
  85                 return copy_user_generic(dst, (__force void *)src, size);
  86         }
  87 }
  88
  89 static __always_inline __must_check
  90 int __copy_to_user(void __user *dst, const void *src, unsigned size)
  91 {
  92         int ret = 0;
  93
  94         might_fault();
  95         if (!__builtin_constant_p(size))
  96                 return copy_user_generic((__force void *)dst, src, size);
  97         switch (size) {
  98         case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
  99                               ret, "b", "b", "iq", 1);
 100                 return ret;
 101         case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
 102                               ret, "w", "w", "ir", 2);
 103                 return ret;
 104         case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
 105                               ret, "l", "k", "ir", 4);
 106                 return ret;
 107         case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
 108                               ret, "q", "", "er", 8);
 109                 return ret;
 110         case 10:
 111                 __put_user_asm(*(u64 *)src, (u64 __user *)dst,
 112                                ret, "q", "", "er", 10);
 113                 if (unlikely(ret))
 114                         return ret;
 115                 asm("":::"memory");
 116                 __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
 117                                ret, "w", "w", "ir", 2);
 118                 return ret;
 119         case 16:
 120                 __put_user_asm(*(u64 *)src, (u64 __user *)dst,
 121                                ret, "q", "", "er", 16);
 122                 if (unlikely(ret))
 123                         return ret;
 124                 asm("":::"memory");
 125                 __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
 126                                ret, "q", "", "er", 8);
 127                 return ret;
 128         default:
 129                 return copy_user_generic((__force void *)dst, src, size);
 130         }
 131 }
 132
 133 static __always_inline __must_check
 134 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 135 {
 136         int ret = 0;
 137
 138         might_fault();
 139         if (!__builtin_constant_p(size))
 140                 return copy_user_generic((__force void *)dst,
 141                                          (__force void *)src, size);
 142         switch (size) {
 143         case 1: {
 144                 u8 tmp;
 145                 __get_user_asm(tmp, (u8 __user *)src,
 146                                ret, "b", "b", "=q", 1);
 147                 if (likely(!ret))
 148                         __put_user_asm(tmp, (u8 __user *)dst,
 149                                        ret, "b", "b", "iq", 1);
 150                 return ret;
 151         }
 152         case 2: {
 153                 u16 tmp;
 154                 __get_user_asm(tmp, (u16 __user *)src,
 155                                ret, "w", "w", "=r", 2);
 156                 if (likely(!ret))
 157                         __put_user_asm(tmp, (u16 __user *)dst,
 158                                        ret, "w", "w", "ir", 2);
 159                 return ret;
 160         }
 161
 162         case 4: {
 163                 u32 tmp;
 164                 __get_user_asm(tmp, (u32 __user *)src,
 165                                ret, "l", "k", "=r", 4);
 166                 if (likely(!ret))
 167                         __put_user_asm(tmp, (u32 __user *)dst,
 168                                        ret, "l", "k", "ir", 4);
 169                 return ret;
 170         }
 171         case 8: {
 172                 u64 tmp;
 173                 __get_user_asm(tmp, (u64 __user *)src,
 174                                ret, "q", "", "=r", 8);
 175                 if (likely(!ret))
 176                         __put_user_asm(tmp, (u64 __user *)dst,
 177                                        ret, "q", "", "er", 8);
 178                 return ret;
 179         }
 180         default:
 181                 return copy_user_generic((__force void *)dst,
 182                                          (__force void *)src, size);
 183         }
 184 }
 185
 186 __must_check long
 187 strncpy_from_user(char *dst, const char __user *src, long count);
 188 __must_check long
 189 __strncpy_from_user(char *dst, const char __user *src, long count);
 190 __must_check long strnlen_user(const char __user *str, long n);
 191 __must_check long __strnlen_user(const char __user *str, long n);
 192 __must_check long strlen_user(const char __user *str);
 193 __must_check unsigned long clear_user(void __user *mem, unsigned long len);
 194 __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
 195
 196 __must_check long __copy_from_user_inatomic(void *dst, const void __user *src,
 197                                             unsigned size);
 198
 199 static __must_check __always_inline int
 200 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
 201 {
 202         return copy_user_generic((__force void *)dst, src, size);
 203 }
 204
 205 extern long __copy_user_nocache(void *dst, const void __user *src,
 206                                 unsigned size, int zerorest);
 207
 208 static inline int
 209 __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
 210 {
 211         might_sleep();
 212         return __copy_user_nocache(dst, src, size, 1);
 213 }
 214
 215 static inline int
 216 __copy_from_user_inatomic_nocache(void *dst, const void __user *src,
 217                                   unsigned size)
 218 {
 219         return __copy_user_nocache(dst, src, size, 0);
 220 }
 221
 222 unsigned long
 223 copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);
 224
 225 #endif /* _ASM_X86_UACCESS_64_H */