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_KMEMCHECK 35 #if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4 36 #define memcpy(dst, src, len) \ 37 ({ \ 38 size_t __len = (len); \ 39 void *__ret; \ 40 if (__builtin_constant_p(len) && __len >= 64) \ 41 __ret = __memcpy((dst), (src), __len); \ 42 else \ 43 __ret = __builtin_memcpy((dst), (src), __len); \ 44 __ret; \ 45 }) 46 #endif 47 #else 48 /* 49 * kmemcheck becomes very happy if we use the REP instructions unconditionally, 50 * because it means that we know both memory operands in advance. 51 */ 52 #define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len)) 53 #endif 54 55 #define __HAVE_ARCH_MEMSET 56 void *memset(void *s, int c, size_t n); 57 void *__memset(void *s, int c, size_t n); 58 59 #define __HAVE_ARCH_MEMMOVE 60 void *memmove(void *dest, const void *src, size_t count); 61 void *__memmove(void *dest, const void *src, size_t count); 62 63 int memcmp(const void *cs, const void *ct, size_t count); 64 size_t strlen(const char *s); 65 char *strcpy(char *dest, const char *src); 66 char *strcat(char *dest, const char *src); 67 int strcmp(const char *cs, const char *ct); 68 69 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) 70 71 /* 72 * For files that not instrumented (e.g. mm/slub.c) we 73 * should use not instrumented version of mem* functions. 74 */ 75 76 #undef memcpy 77 #define memcpy(dst, src, len) __memcpy(dst, src, len) 78 #define memmove(dst, src, len) __memmove(dst, src, len) 79 #define memset(s, c, n) __memset(s, c, n) 80 #endif 81 82 __must_check int memcpy_mcsafe_unrolled(void *dst, const void *src, size_t cnt); 83 DECLARE_STATIC_KEY_FALSE(mcsafe_key); 84 85 /** 86 * memcpy_mcsafe - copy memory with indication if a machine check happened 87 * 88 * @dst: destination address 89 * @src: source address 90 * @cnt: number of bytes to copy 91 * 92 * Low level memory copy function that catches machine checks 93 * We only call into the "safe" function on systems that can 94 * actually do machine check recovery. Everyone else can just 95 * use memcpy(). 96 * 97 * Return 0 for success, -EFAULT for fail 98 */ 99 static __always_inline __must_check int 100 memcpy_mcsafe(void *dst, const void *src, size_t cnt) 101 { 102 #ifdef CONFIG_X86_MCE 103 if (static_branch_unlikely(&mcsafe_key)) 104 return memcpy_mcsafe_unrolled(dst, src, cnt); 105 else 106 #endif 107 memcpy(dst, src, cnt); 108 return 0; 109 } 110 111 #endif /* __KERNEL__ */ 112 113 #endif /* _ASM_X86_STRING_64_H */ 114