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 #ifndef CONFIG_KMEMCHECK
  37 #if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
  38 #define memcpy(dst, src, len)                                   \
  39 ({                                                              \
  40         size_t __len = (len);                                   \
  41         void *__ret;                                            \
  42         if (__builtin_constant_p(len) && __len >= 64)           \
  43                 __ret = __memcpy((dst), (src), __len);          \
  44         else                                                    \
  45                 __ret = __builtin_memcpy((dst), (src), __len);  \
  46         __ret;                                                  \
  47 })
  48 #endif
  49 #else
  50 /*
  51  * kmemcheck becomes very happy if we use the REP instructions unconditionally,
  52  * because it means that we know both memory operands in advance.
  53  */
  54 #define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
  55 #endif
  56 #endif /* !CONFIG_FORTIFY_SOURCE */
  57
  58 #define __HAVE_ARCH_MEMSET
  59 void *memset(void *s, int c, size_t n);
  60 void *__memset(void *s, int c, size_t n);
  61
  62 #define __HAVE_ARCH_MEMSET16
  63 static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
  64 {
  65         long d0, d1;
  66         asm volatile("rep\n\t"
  67                      "stosw"
  68                      : "=&c" (d0), "=&D" (d1)
  69                      : "a" (v), "1" (s), "0" (n)
  70                      : "memory");
  71         return s;
  72 }
  73
  74 #define __HAVE_ARCH_MEMSET32
  75 static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
  76 {
  77         long d0, d1;
  78         asm volatile("rep\n\t"
  79                      "stosl"
  80                      : "=&c" (d0), "=&D" (d1)
  81                      : "a" (v), "1" (s), "0" (n)
  82                      : "memory");
  83         return s;
  84 }
  85
  86 #define __HAVE_ARCH_MEMSET64
  87 static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
  88 {
  89         long d0, d1;
  90         asm volatile("rep\n\t"
  91                      "stosq"
  92                      : "=&c" (d0), "=&D" (d1)
  93                      : "a" (v), "1" (s), "0" (n)
  94                      : "memory");
  95         return s;
  96 }
  97
  98 #define __HAVE_ARCH_MEMMOVE
  99 void *memmove(void *dest, const void *src, size_t count);
 100 void *__memmove(void *dest, const void *src, size_t count);
 101
 102 int memcmp(const void *cs, const void *ct, size_t count);
 103 size_t strlen(const char *s);
 104 char *strcpy(char *dest, const char *src);
 105 char *strcat(char *dest, const char *src);
 106 int strcmp(const char *cs, const char *ct);
 107
 108 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
 109
 110 /*
 111  * For files that not instrumented (e.g. mm/slub.c) we
 112  * should use not instrumented version of mem* functions.
 113  */
 114
 115 #undef memcpy
 116 #define memcpy(dst, src, len) __memcpy(dst, src, len)
 117 #define memmove(dst, src, len) __memmove(dst, src, len)
 118 #define memset(s, c, n) __memset(s, c, n)
 119
 120 #ifndef __NO_FORTIFY
 121 #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
 122 #endif
 123
 124 #endif
 125
 126 #define __HAVE_ARCH_MEMCPY_MCSAFE 1
 127 __must_check int memcpy_mcsafe_unrolled(void *dst, const void *src, size_t cnt);
 128 DECLARE_STATIC_KEY_FALSE(mcsafe_key);
 129
 130 /**
 131  * memcpy_mcsafe - copy memory with indication if a machine check happened
 132  *
 133  * @dst:        destination address
 134  * @src:        source address
 135  * @cnt:        number of bytes to copy
 136  *
 137  * Low level memory copy function that catches machine checks
 138  * We only call into the "safe" function on systems that can
 139  * actually do machine check recovery. Everyone else can just
 140  * use memcpy().
 141  *
 142  * Return 0 for success, -EFAULT for fail
 143  */
 144 static __always_inline __must_check int
 145 memcpy_mcsafe(void *dst, const void *src, size_t cnt)
 146 {
 147 #ifdef CONFIG_X86_MCE
 148         if (static_branch_unlikely(&mcsafe_key))
 149                 return memcpy_mcsafe_unrolled(dst, src, cnt);
 150         else
 151 #endif
 152                 memcpy(dst, src, cnt);
 153         return 0;
 154 }
 155
 156 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 157 #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
 158 void memcpy_flushcache(void *dst, const void *src, size_t cnt);
 159 #endif
 160
 161 #endif /* __KERNEL__ */
 162
 163 #endif /* _ASM_X86_STRING_64_H */