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         might_fault();
  36         if (likely(sz == -1 || sz >= n))
  37                 ret = _copy_from_user(to, from, n);
  38 #ifdef CONFIG_DEBUG_VM
  39         else
  40                 WARN(1, "Buffer overflow detected!\n");
  41 #endif
  42         return ret;
  43 }
  44
  45 static __always_inline __must_check
  46 int copy_to_user(void __user *dst, const void *src, unsigned size)
  47 {
  48         might_fault();
  49
  50         return _copy_to_user(dst, src, size);
  51 }
  52
  53 static __always_inline __must_check
  54 int __copy_from_user(void *dst, const void __user *src, unsigned size)
  55 {
  56         int ret = 0;
  57
  58         might_fault();
  59         if (!__builtin_constant_p(size))
  60                 return copy_user_generic(dst, (__force void *)src, size);
  61         switch (size) {
  62         case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
  63                               ret, "b", "b", "=q", 1);
  64                 return ret;
  65         case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
  66                               ret, "w", "w", "=r", 2);
  67                 return ret;
  68         case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
  69                               ret, "l", "k", "=r", 4);
  70                 return ret;
  71         case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
  72                               ret, "q", "", "=r", 8);
  73                 return ret;
  74         case 10:
  75                 __get_user_asm(*(u64 *)dst, (u64 __user *)src,
  76                                ret, "q", "", "=r", 10);
  77                 if (unlikely(ret))
  78                         return ret;
  79                 __get_user_asm(*(u16 *)(8 + (char *)dst),
  80                                (u16 __user *)(8 + (char __user *)src),
  81                                ret, "w", "w", "=r", 2);
  82                 return ret;
  83         case 16:
  84                 __get_user_asm(*(u64 *)dst, (u64 __user *)src,
  85                                ret, "q", "", "=r", 16);
  86                 if (unlikely(ret))
  87                         return ret;
  88                 __get_user_asm(*(u64 *)(8 + (char *)dst),
  89                                (u64 __user *)(8 + (char __user *)src),
  90                                ret, "q", "", "=r", 8);
  91                 return ret;
  92         default:
  93                 return copy_user_generic(dst, (__force void *)src, size);
  94         }
  95 }
  96
  97 static __always_inline __must_check
  98 int __copy_to_user(void __user *dst, const void *src, unsigned size)
  99 {
 100         int ret = 0;
 101
 102         might_fault();
 103         if (!__builtin_constant_p(size))
 104                 return copy_user_generic((__force void *)dst, src, size);
 105         switch (size) {
 106         case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
 107                               ret, "b", "b", "iq", 1);
 108                 return ret;
 109         case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
 110                               ret, "w", "w", "ir", 2);
 111                 return ret;
 112         case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
 113                               ret, "l", "k", "ir", 4);
 114                 return ret;
 115         case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
 116                               ret, "q", "", "er", 8);
 117                 return ret;
 118         case 10:
 119                 __put_user_asm(*(u64 *)src, (u64 __user *)dst,
 120                                ret, "q", "", "er", 10);
 121                 if (unlikely(ret))
 122                         return ret;
 123                 asm("":::"memory");
 124                 __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
 125                                ret, "w", "w", "ir", 2);
 126                 return ret;
 127         case 16:
 128                 __put_user_asm(*(u64 *)src, (u64 __user *)dst,
 129                                ret, "q", "", "er", 16);
 130                 if (unlikely(ret))
 131                         return ret;
 132                 asm("":::"memory");
 133                 __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
 134                                ret, "q", "", "er", 8);
 135                 return ret;
 136         default:
 137                 return copy_user_generic((__force void *)dst, src, size);
 138         }
 139 }
 140
 141 static __always_inline __must_check
 142 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 143 {
 144         int ret = 0;
 145
 146         might_fault();
 147         if (!__builtin_constant_p(size))
 148                 return copy_user_generic((__force void *)dst,
 149                                          (__force void *)src, size);
 150         switch (size) {
 151         case 1: {
 152                 u8 tmp;
 153                 __get_user_asm(tmp, (u8 __user *)src,
 154                                ret, "b", "b", "=q", 1);
 155                 if (likely(!ret))
 156                         __put_user_asm(tmp, (u8 __user *)dst,
 157                                        ret, "b", "b", "iq", 1);
 158                 return ret;
 159         }
 160         case 2: {
 161                 u16 tmp;
 162                 __get_user_asm(tmp, (u16 __user *)src,
 163                                ret, "w", "w", "=r", 2);
 164                 if (likely(!ret))
 165                         __put_user_asm(tmp, (u16 __user *)dst,
 166                                        ret, "w", "w", "ir", 2);
 167                 return ret;
 168         }
 169
 170         case 4: {
 171                 u32 tmp;
 172                 __get_user_asm(tmp, (u32 __user *)src,
 173                                ret, "l", "k", "=r", 4);
 174                 if (likely(!ret))
 175                         __put_user_asm(tmp, (u32 __user *)dst,
 176                                        ret, "l", "k", "ir", 4);
 177                 return ret;
 178         }
 179         case 8: {
 180                 u64 tmp;
 181                 __get_user_asm(tmp, (u64 __user *)src,
 182                                ret, "q", "", "=r", 8);
 183                 if (likely(!ret))
 184                         __put_user_asm(tmp, (u64 __user *)dst,
 185                                        ret, "q", "", "er", 8);
 186                 return ret;
 187         }
 188         default:
 189                 return copy_user_generic((__force void *)dst,
 190                                          (__force void *)src, size);
 191         }
 192 }
 193
 194 __must_check long
 195 strncpy_from_user(char *dst, const char __user *src, long count);
 196 __must_check long
 197 __strncpy_from_user(char *dst, const char __user *src, long count);
 198 __must_check long strnlen_user(const char __user *str, long n);
 199 __must_check long __strnlen_user(const char __user *str, long n);
 200 __must_check long strlen_user(const char __user *str);
 201 __must_check unsigned long clear_user(void __user *mem, unsigned long len);
 202 __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
 203
 204 static __must_check __always_inline int
 205 __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
 206 {
 207         return copy_user_generic(dst, (__force const void *)src, size);
 208 }
 209
 210 static __must_check __always_inline int
 211 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
 212 {
 213         return copy_user_generic((__force void *)dst, src, size);
 214 }
 215
 216 extern long __copy_user_nocache(void *dst, const void __user *src,
 217                                 unsigned size, int zerorest);
 218
 219 static inline int
 220 __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
 221 {
 222         might_sleep();
 223         return __copy_user_nocache(dst, src, size, 1);
 224 }
 225
 226 static inline int
 227 __copy_from_user_inatomic_nocache(void *dst, const void __user *src,
 228                                   unsigned size)
 229 {
 230         return __copy_user_nocache(dst, src, size, 0);
 231 }
 232
 233 unsigned long
 234 copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);
 235
 236 #endif /* _ASM_X86_UACCESS_64_H */