arch/x86/include/asm/string_64.h

   1 #ifndef _ASM_X86_STRING_64_H
   2 #define _ASM_X86_STRING_64_H
   3
   4 #ifdef __KERNEL__
   5 #include <linux/jump_label.h>
   6
   7 /* Written 2002 by Andi Kleen */
   8
   9 /* Only used for special circumstances. Stolen from i386/string.h */
  10 static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
  11 {
  12         unsigned long d0, d1, d2;
  13         asm volatile("rep ; movsl\n\t"
  14                      "testb $2,%b4\n\t"
  15                      "je 1f\n\t"
  16                      "movsw\n"
  17                      "1:\ttestb $1,%b4\n\t"
  18                      "je 2f\n\t"
  19                      "movsb\n"
  20                      "2:"
  21                      : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  22                      : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
  23                      : "memory");
  24         return to;
  25 }
  26
  27 /* Even with __builtin_ the compiler may decide to use the out of line
  28    function. */
  29
  30 #define __HAVE_ARCH_MEMCPY 1
  31 extern void *memcpy(void *to, const void *from, size_t len);
  32 extern void *__memcpy(void *to, const void *from, size_t len);
  33
  34 #ifndef CONFIG_FORTIFY_SOURCE
  35 #ifndef CONFIG_KMEMCHECK
  36 #if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
  37 #define memcpy(dst, src, len)                                   \
  38 ({                                                              \
  39         size_t __len = (len);                                   \
  40         void *__ret;                                            \
  41         if (__builtin_constant_p(len) && __len >= 64)           \
  42                 __ret = __memcpy((dst), (src), __len);          \
  43         else                                                    \
  44                 __ret = __builtin_memcpy((dst), (src), __len);  \
  45         __ret;                                                  \
  46 })
  47 #endif
  48 #else
  49 /*
  50  * kmemcheck becomes very happy if we use the REP instructions unconditionally,
  51  * because it means that we know both memory operands in advance.
  52  */
  53 #define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
  54 #endif
  55 #endif /* !CONFIG_FORTIFY_SOURCE */
  56
  57 #define __HAVE_ARCH_MEMSET
  58 void *memset(void *s, int c, size_t n);
  59 void *__memset(void *s, int c, size_t n);
  60
  61 #define __HAVE_ARCH_MEMMOVE
  62 void *memmove(void *dest, const void *src, size_t count);
  63 void *__memmove(void *dest, const void *src, size_t count);
  64
  65 int memcmp(const void *cs, const void *ct, size_t count);
  66 size_t strlen(const char *s);
  67 char *strcpy(char *dest, const char *src);
  68 char *strcat(char *dest, const char *src);
  69 int strcmp(const char *cs, const char *ct);
  70
  71 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
  72
  73 /*
  74  * For files that not instrumented (e.g. mm/slub.c) we
  75  * should use not instrumented version of mem* functions.
  76  */
  77
  78 #undef memcpy
  79 #define memcpy(dst, src, len) __memcpy(dst, src, len)
  80 #define memmove(dst, src, len) __memmove(dst, src, len)
  81 #define memset(s, c, n) __memset(s, c, n)
  82
  83 #ifndef __NO_FORTIFY
  84 #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
  85 #endif
  86
  87 #endif
  88
  89 #define __HAVE_ARCH_MEMCPY_MCSAFE 1
  90 __must_check int memcpy_mcsafe_unrolled(void *dst, const void *src, size_t cnt);
  91 DECLARE_STATIC_KEY_FALSE(mcsafe_key);
  92
  93 /**
  94  * memcpy_mcsafe - copy memory with indication if a machine check happened
  95  *
  96  * @dst:        destination address
  97  * @src:        source address
  98  * @cnt:        number of bytes to copy
  99  *
 100  * Low level memory copy function that catches machine checks
 101  * We only call into the "safe" function on systems that can
 102  * actually do machine check recovery. Everyone else can just
 103  * use memcpy().
 104  *
 105  * Return 0 for success, -EFAULT for fail
 106  */
 107 static __always_inline __must_check int
 108 memcpy_mcsafe(void *dst, const void *src, size_t cnt)
 109 {
 110 #ifdef CONFIG_X86_MCE
 111         if (static_branch_unlikely(&mcsafe_key))
 112                 return memcpy_mcsafe_unrolled(dst, src, cnt);
 113         else
 114 #endif
 115                 memcpy(dst, src, cnt);
 116         return 0;
 117 }
 118
 119 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 120 #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
 121 void memcpy_flushcache(void *dst, const void *src, size_t cnt);
 122 #endif
 123
 124 #endif /* __KERNEL__ */
 125
 126 #endif /* _ASM_X86_STRING_64_H */