include/asm-x86/uaccess_64.h

   1 #ifndef __X86_64_UACCESS_H
   2 #define __X86_64_UACCESS_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 <asm/page.h>
  11
  12 #define __addr_ok(addr) (!((unsigned long)(addr) &                      \
  13                            (current_thread_info()->addr_limit.seg)))
  14
  15 #define ARCH_HAS_SEARCH_EXTABLE
  16
  17 extern void __put_user_1(void);
  18 extern void __put_user_2(void);
  19 extern void __put_user_4(void);
  20 extern void __put_user_8(void);
  21 extern void __put_user_bad(void);
  22
  23 #define __put_user_x(size, ret, x, ptr)                                 \
  24         asm volatile("call __put_user_" #size                           \
  25                      :"=a" (ret)                                        \
  26                      :"c" (ptr),"a" (x)                                 \
  27                      :"ebx")
  28
  29 #define put_user(x, ptr)                                                \
  30         __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
  31
  32 #define __get_user(x, ptr)                                              \
  33         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  34 #define __put_user(x, ptr)                                              \
  35         __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
  36
  37 #define __get_user_unaligned __get_user
  38 #define __put_user_unaligned __put_user
  39
  40 #define __put_user_nocheck(x, ptr, size)                \
  41 ({                                                      \
  42         int __pu_err;                                   \
  43         __put_user_size((x), (ptr), (size), __pu_err);  \
  44         __pu_err;                                       \
  45 })
  46
  47
  48 #define __put_user_check(x, ptr, size)                          \
  49 ({                                                              \
  50         int __pu_err;                                           \
  51         typeof(*(ptr)) __user *__pu_addr = (ptr);               \
  52         switch (size) {                                         \
  53         case 1:                                                 \
  54                 __put_user_x(1, __pu_err, x, __pu_addr);        \
  55                 break;                                          \
  56         case 2:                                                 \
  57                 __put_user_x(2, __pu_err, x, __pu_addr);        \
  58                 break;                                          \
  59         case 4:                                                 \
  60                 __put_user_x(4, __pu_err, x, __pu_addr);        \
  61                 break;                                          \
  62         case 8:                                                 \
  63                 __put_user_x(8, __pu_err, x, __pu_addr);        \
  64                 break;                                          \
  65         default:                                                \
  66                 __put_user_bad();                               \
  67         }                                                       \
  68         __pu_err;                                               \
  69 })
  70
  71 #define __put_user_size(x, ptr, size, retval)                           \
  72 do {                                                                    \
  73         retval = 0;                                                     \
  74         __chk_user_ptr(ptr);                                            \
  75         switch (size) {                                                 \
  76         case 1:                                                         \
  77                 __put_user_asm(x, ptr, retval, "b", "b", "iq", -EFAULT);\
  78                 break;                                                  \
  79         case 2:                                                         \
  80                 __put_user_asm(x, ptr, retval, "w", "w", "ir", -EFAULT);\
  81                 break;                                                  \
  82         case 4:                                                         \
  83                 __put_user_asm(x, ptr, retval, "l", "k", "ir", -EFAULT);\
  84                 break;                                                  \
  85         case 8:                                                         \
  86                 __put_user_asm(x, ptr, retval, "q", "", "Zr", -EFAULT); \
  87                 break;                                                  \
  88         default:                                                        \
  89                 __put_user_bad();                                       \
  90         }                                                               \
  91 } while (0)
  92
  93 /* FIXME: this hack is definitely wrong -AK */
  94 struct __large_struct { unsigned long buf[100]; };
  95 #define __m(x) (*(struct __large_struct __user *)(x))
  96
  97 /*
  98  * Tell gcc we read from memory instead of writing: this is because
  99  * we do not write to any memory gcc knows about, so there are no
 100  * aliasing issues.
 101  */
 102 #define __put_user_asm(x, addr, err, itype, rtype, ltype, errno)        \
 103         asm volatile("1:        mov"itype" %"rtype"1,%2\n"              \
 104                      "2:\n"                                             \
 105                      ".section .fixup, \"ax\"\n"                        \
 106                      "3:        mov %3,%0\n"                            \
 107                      "  jmp 2b\n"                                       \
 108                      ".previous\n"                                      \
 109                      _ASM_EXTABLE(1b, 3b)                               \
 110                      : "=r"(err)                                        \
 111                      : ltype (x), "m" (__m(addr)), "i" (errno), "0" (err))
 112
 113
 114 #define __get_user_nocheck(x, ptr, size)                        \
 115 ({                                                              \
 116         int __gu_err;                                           \
 117         unsigned long __gu_val;                                 \
 118         __get_user_size(__gu_val, (ptr), (size), __gu_err);     \
 119         (x) = (__force typeof(*(ptr)))__gu_val;                 \
 120         __gu_err;                                               \
 121 })
 122
 123 #define __get_user_size(x, ptr, size, retval)                           \
 124 do {                                                                    \
 125         retval = 0;                                                     \
 126         __chk_user_ptr(ptr);                                            \
 127         switch (size) {                                                 \
 128         case 1:                                                         \
 129                 __get_user_asm(x, ptr, retval, "b", "b", "=q", -EFAULT);\
 130                 break;                                                  \
 131         case 2:                                                         \
 132                 __get_user_asm(x, ptr, retval, "w", "w", "=r", -EFAULT);\
 133                 break;                                                  \
 134         case 4:                                                         \
 135                 __get_user_asm(x, ptr, retval, "l", "k", "=r", -EFAULT);\
 136                 break;                                                  \
 137         case 8:                                                         \
 138                 __get_user_asm(x, ptr, retval, "q", "", "=r", -EFAULT); \
 139                 break;                                                  \
 140         default:                                                        \
 141                 (x) = __get_user_bad();                                 \
 142         }                                                               \
 143 } while (0)
 144
 145 #define __get_user_asm(x, addr, err, itype, rtype, ltype, errno)        \
 146         asm volatile("1:        mov"itype" %2,%"rtype"1\n"              \
 147                      "2:\n"                                             \
 148                      ".section .fixup, \"ax\"\n"                        \
 149                      "3:        mov %3,%0\n"                            \
 150                      "  xor"itype" %"rtype"1,%"rtype"1\n"               \
 151                      "  jmp 2b\n"                                       \
 152                      ".previous\n"                                      \
 153                      _ASM_EXTABLE(1b, 3b)                               \
 154                      : "=r" (err), ltype (x)                            \
 155                      : "m" (__m(addr)), "i"(errno), "0"(err))
 156
 157 /*
 158  * Copy To/From Userspace
 159  */
 160
 161 /* Handles exceptions in both to and from, but doesn't do access_ok */
 162 __must_check unsigned long
 163 copy_user_generic(void *to, const void *from, unsigned len);
 164
 165 __must_check unsigned long
 166 copy_to_user(void __user *to, const void *from, unsigned len);
 167 __must_check unsigned long
 168 copy_from_user(void *to, const void __user *from, unsigned len);
 169 __must_check unsigned long
 170 copy_in_user(void __user *to, const void __user *from, unsigned len);
 171
 172 static __always_inline __must_check
 173 int __copy_from_user(void *dst, const void __user *src, unsigned size)
 174 {
 175         int ret = 0;
 176         if (!__builtin_constant_p(size))
 177                 return copy_user_generic(dst, (__force void *)src, size);
 178         switch (size) {
 179         case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
 180                               ret, "b", "b", "=q", 1);
 181                 return ret;
 182         case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
 183                               ret, "w", "w", "=r", 2);
 184                 return ret;
 185         case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
 186                               ret, "l", "k", "=r", 4);
 187                 return ret;
 188         case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
 189                               ret, "q", "", "=r", 8);
 190                 return ret;
 191         case 10:
 192                 __get_user_asm(*(u64 *)dst, (u64 __user *)src,
 193                                ret, "q", "", "=r", 16);
 194                 if (unlikely(ret))
 195                         return ret;
 196                 __get_user_asm(*(u16 *)(8 + (char *)dst),
 197                                (u16 __user *)(8 + (char __user *)src),
 198                                ret, "w", "w", "=r", 2);
 199                 return ret;
 200         case 16:
 201                 __get_user_asm(*(u64 *)dst, (u64 __user *)src,
 202                                ret, "q", "", "=r", 16);
 203                 if (unlikely(ret))
 204                         return ret;
 205                 __get_user_asm(*(u64 *)(8 + (char *)dst),
 206                                (u64 __user *)(8 + (char __user *)src),
 207                                ret, "q", "", "=r", 8);
 208                 return ret;
 209         default:
 210                 return copy_user_generic(dst, (__force void *)src, size);
 211         }
 212 }
 213
 214 static __always_inline __must_check
 215 int __copy_to_user(void __user *dst, const void *src, unsigned size)
 216 {
 217         int ret = 0;
 218         if (!__builtin_constant_p(size))
 219                 return copy_user_generic((__force void *)dst, src, size);
 220         switch (size) {
 221         case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
 222                               ret, "b", "b", "iq", 1);
 223                 return ret;
 224         case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
 225                               ret, "w", "w", "ir", 2);
 226                 return ret;
 227         case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
 228                               ret, "l", "k", "ir", 4);
 229                 return ret;
 230         case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
 231                               ret, "q", "", "ir", 8);
 232                 return ret;
 233         case 10:
 234                 __put_user_asm(*(u64 *)src, (u64 __user *)dst,
 235                                ret, "q", "", "ir", 10);
 236                 if (unlikely(ret))
 237                         return ret;
 238                 asm("":::"memory");
 239                 __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
 240                                ret, "w", "w", "ir", 2);
 241                 return ret;
 242         case 16:
 243                 __put_user_asm(*(u64 *)src, (u64 __user *)dst,
 244                                ret, "q", "", "ir", 16);
 245                 if (unlikely(ret))
 246                         return ret;
 247                 asm("":::"memory");
 248                 __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
 249                                ret, "q", "", "ir", 8);
 250                 return ret;
 251         default:
 252                 return copy_user_generic((__force void *)dst, src, size);
 253         }
 254 }
 255
 256 static __always_inline __must_check
 257 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 258 {
 259         int ret = 0;
 260         if (!__builtin_constant_p(size))
 261                 return copy_user_generic((__force void *)dst,
 262                                          (__force void *)src, size);
 263         switch (size) {
 264         case 1: {
 265                 u8 tmp;
 266                 __get_user_asm(tmp, (u8 __user *)src,
 267                                ret, "b", "b", "=q", 1);
 268                 if (likely(!ret))
 269                         __put_user_asm(tmp, (u8 __user *)dst,
 270                                        ret, "b", "b", "iq", 1);
 271                 return ret;
 272         }
 273         case 2: {
 274                 u16 tmp;
 275                 __get_user_asm(tmp, (u16 __user *)src,
 276                                ret, "w", "w", "=r", 2);
 277                 if (likely(!ret))
 278                         __put_user_asm(tmp, (u16 __user *)dst,
 279                                        ret, "w", "w", "ir", 2);
 280                 return ret;
 281         }
 282
 283         case 4: {
 284                 u32 tmp;
 285                 __get_user_asm(tmp, (u32 __user *)src,
 286                                ret, "l", "k", "=r", 4);
 287                 if (likely(!ret))
 288                         __put_user_asm(tmp, (u32 __user *)dst,
 289                                        ret, "l", "k", "ir", 4);
 290                 return ret;
 291         }
 292         case 8: {
 293                 u64 tmp;
 294                 __get_user_asm(tmp, (u64 __user *)src,
 295                                ret, "q", "", "=r", 8);
 296                 if (likely(!ret))
 297                         __put_user_asm(tmp, (u64 __user *)dst,
 298                                        ret, "q", "", "ir", 8);
 299                 return ret;
 300         }
 301         default:
 302                 return copy_user_generic((__force void *)dst,
 303                                          (__force void *)src, size);
 304         }
 305 }
 306
 307 __must_check long
 308 strncpy_from_user(char *dst, const char __user *src, long count);
 309 __must_check long
 310 __strncpy_from_user(char *dst, const char __user *src, long count);
 311 __must_check long strnlen_user(const char __user *str, long n);
 312 __must_check long __strnlen_user(const char __user *str, long n);
 313 __must_check long strlen_user(const char __user *str);
 314 __must_check unsigned long clear_user(void __user *mem, unsigned long len);
 315 __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
 316
 317 __must_check long __copy_from_user_inatomic(void *dst, const void __user *src,
 318                                             unsigned size);
 319
 320 static __must_check __always_inline int
 321 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
 322 {
 323         return copy_user_generic((__force void *)dst, src, size);
 324 }
 325
 326 #define ARCH_HAS_NOCACHE_UACCESS 1
 327 extern long __copy_user_nocache(void *dst, const void __user *src,
 328                                 unsigned size, int zerorest);
 329
 330 static inline int __copy_from_user_nocache(void *dst, const void __user *src,
 331                                            unsigned size)
 332 {
 333         might_sleep();
 334         return __copy_user_nocache(dst, src, size, 1);
 335 }
 336
 337 static inline int __copy_from_user_inatomic_nocache(void *dst,
 338                                                     const void __user *src,
 339                                                     unsigned size)
 340 {
 341         return __copy_user_nocache(dst, src, size, 0);
 342 }
 343
 344 #endif /* __X86_64_UACCESS_H */