arch/x86/include/asm/string_64.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_STRING_64_H
   3 #define _ASM_X86_STRING_64_H
   4
   5 #ifdef __KERNEL__
   6 #include <linux/jump_label.h>
   7
   8 /* Written 2002 by Andi Kleen */
   9
  10 /* Only used for special circumstances. Stolen from i386/string.h */
  11 static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
  12 {
  13         unsigned long d0, d1, d2;
  14         asm volatile("rep ; movsl\n\t"
  15                      "testb $2,%b4\n\t"
  16                      "je 1f\n\t"
  17                      "movsw\n"
  18                      "1:\ttestb $1,%b4\n\t"
  19                      "je 2f\n\t"
  20                      "movsb\n"
  21                      "2:"
  22                      : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  23                      : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
  24                      : "memory");
  25         return to;
  26 }
  27
  28 /* Even with __builtin_ the compiler may decide to use the out of line
  29    function. */
  30
  31 #define __HAVE_ARCH_MEMCPY 1
  32 extern void *memcpy(void *to, const void *from, size_t len);
  33 extern void *__memcpy(void *to, const void *from, size_t len);
  34
  35 #ifndef CONFIG_FORTIFY_SOURCE
  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 #endif /* !CONFIG_FORTIFY_SOURCE */
  49
  50 #define __HAVE_ARCH_MEMSET
  51 void *memset(void *s, int c, size_t n);
  52 void *__memset(void *s, int c, size_t n);
  53
  54 #define __HAVE_ARCH_MEMSET16
  55 static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
  56 {
  57         long d0, d1;
  58         asm volatile("rep\n\t"
  59                      "stosw"
  60                      : "=&c" (d0), "=&D" (d1)
  61                      : "a" (v), "1" (s), "0" (n)
  62                      : "memory");
  63         return s;
  64 }
  65
  66 #define __HAVE_ARCH_MEMSET32
  67 static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
  68 {
  69         long d0, d1;
  70         asm volatile("rep\n\t"
  71                      "stosl"
  72                      : "=&c" (d0), "=&D" (d1)
  73                      : "a" (v), "1" (s), "0" (n)
  74                      : "memory");
  75         return s;
  76 }
  77
  78 #define __HAVE_ARCH_MEMSET64
  79 static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
  80 {
  81         long d0, d1;
  82         asm volatile("rep\n\t"
  83                      "stosq"
  84                      : "=&c" (d0), "=&D" (d1)
  85                      : "a" (v), "1" (s), "0" (n)
  86                      : "memory");
  87         return s;
  88 }
  89
  90 #define __HAVE_ARCH_MEMMOVE
  91 void *memmove(void *dest, const void *src, size_t count);
  92 void *__memmove(void *dest, const void *src, size_t count);
  93
  94 int memcmp(const void *cs, const void *ct, size_t count);
  95 size_t strlen(const char *s);
  96 char *strcpy(char *dest, const char *src);
  97 char *strcat(char *dest, const char *src);
  98 int strcmp(const char *cs, const char *ct);
  99
 100 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
 101
 102 /*
 103  * For files that not instrumented (e.g. mm/slub.c) we
 104  * should use not instrumented version of mem* functions.
 105  */
 106
 107 #undef memcpy
 108 #define memcpy(dst, src, len) __memcpy(dst, src, len)
 109 #define memmove(dst, src, len) __memmove(dst, src, len)
 110 #define memset(s, c, n) __memset(s, c, n)
 111
 112 #ifndef __NO_FORTIFY
 113 #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
 114 #endif
 115
 116 #endif
 117
 118 #define __HAVE_ARCH_MEMCPY_MCSAFE 1
 119 __must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
 120                 size_t cnt);
 121 DECLARE_STATIC_KEY_FALSE(mcsafe_key);
 122
 123 /**
 124  * memcpy_mcsafe - copy memory with indication if a machine check happened
 125  *
 126  * @dst:        destination address
 127  * @src:        source address
 128  * @cnt:        number of bytes to copy
 129  *
 130  * Low level memory copy function that catches machine checks
 131  * We only call into the "safe" function on systems that can
 132  * actually do machine check recovery. Everyone else can just
 133  * use memcpy().
 134  *
 135  * Return 0 for success, or number of bytes not copied if there was an
 136  * exception.
 137  */
 138 static __always_inline __must_check unsigned long
 139 memcpy_mcsafe(void *dst, const void *src, size_t cnt)
 140 {
 141 #ifdef CONFIG_X86_MCE
 142         if (static_branch_unlikely(&mcsafe_key))
 143                 return __memcpy_mcsafe(dst, src, cnt);
 144         else
 145 #endif
 146                 memcpy(dst, src, cnt);
 147         return 0;
 148 }
 149
 150 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 151 #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
 152 void memcpy_flushcache(void *dst, const void *src, size_t cnt);
 153 #endif
 154
 155 #endif /* __KERNEL__ */
 156
 157 #endif /* _ASM_X86_STRING_64_H */