// SPDX-License-Identifier: GPL-2.0/* * This provides an optimized implementation of memcpy, and a simplified * implementation of memset and memmove. These are used here because the * standard kernel runtime versions are not yet available and we don't * trust the gcc built-in implementations as they may do unexpected things * (e.g. FPU ops) in the minimal decompression stub execution environment. */#include "error.h" #include "../string.c" #ifdef CONFIG_X86_32static void *____memcpy(void *dest, const void *src, size_t n){	int d0, d1, d2;	asm volatile(		"rep movsl\n\t"		"movl %4,%%ecx\n\t"		"rep movsb"		: "=&c" (d0), "=&D" (d1), "=&S" (d2)		: "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)		: "memory"); 	return dest;}#elsestatic void *____memcpy(void *dest, const void *src, size_t n){	long d0, d1, d2;	asm volatile(		"rep movsq\n\t"		"movq %4,%%rcx\n\t"		"rep movsb"		: "=&c" (d0), "=&D" (d1), "=&S" (d2)		: "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src)		: "memory"); 	return dest;}#endif void *memset(void *s, int c, size_t n){	int i;	char *ss = s; 	for (i = 0; i < n; i++)		ss[i] = c;	return s;} void *memmove(void *dest, const void *src, size_t n){	unsigned char *d = dest;	const unsigned char *s = src; 	if (d <= s || d - s >= n)		return ____memcpy(dest, src, n); 	while (n-- > 0)		d[n] = s[n]; 	return dest;} /* Detect and warn about potential overlaps, but handle them with memmove. */void *memcpy(void *dest, const void *src, size_t n){	if (dest > src && dest - src < n) {		warn("Avoiding potentially unsafe overlapping memcpy()!");		return memmove(dest, src, n);	}	return ____memcpy(dest, src, n);} #ifdef CONFIG_KASANextern void *__memset(void *s, int c, size_t n) __alias(memset);extern void *__memmove(void *dest, const void *src, size_t n) __alias(memmove);extern void *__memcpy(void *dest, const void *src, size_t n) __alias(memcpy);#endif