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