1#include "misc.h"
 2#include "../string.c"
 
 
 
 
 
 
 
 3
 4/* misc.h might pull in string_32.h which has a macro for memcpy. undef that */
 5#undef memcpy
 6
 7#ifdef CONFIG_X86_32
 8void *memcpy(void *dest, const void *src, size_t n)
 9{
10	int d0, d1, d2;
11	asm volatile(
12		"rep ; movsl\n\t"
13		"movl %4,%%ecx\n\t"
14		"rep ; movsb\n\t"
15		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
16		: "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)
17		: "memory");
18
19	return dest;
20}
21#else
22void *memcpy(void *dest, const void *src, size_t n)
23{
24	long d0, d1, d2;
25	asm volatile(
26		"rep ; movsq\n\t"
27		"movq %4,%%rcx\n\t"
28		"rep ; movsb\n\t"
29		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
30		: "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src)
31		: "memory");
32
33	return dest;
34}
35#endif
36
37void *memset(void *s, int c, size_t n)
38{
39	int i;
40	char *ss = s;
41
42	for (i = 0; i < n; i++)
43		ss[i] = c;
44	return s;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
45}

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * This provides an optimized implementation of memcpy, and a simplified
 4 * implementation of memset and memmove. These are used here because the
 5 * standard kernel runtime versions are not yet available and we don't
 6 * trust the gcc built-in implementations as they may do unexpected things
 7 * (e.g. FPU ops) in the minimal decompression stub execution environment.
 8 */
 9#include "error.h"
10
11#include "../string.c"
 
12
13#ifdef CONFIG_X86_32
14static void *__memcpy(void *dest, const void *src, size_t n)
15{
16	int d0, d1, d2;
17	asm volatile(
18		"rep ; movsl\n\t"
19		"movl %4,%%ecx\n\t"
20		"rep ; movsb\n\t"
21		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
22		: "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)
23		: "memory");
24
25	return dest;
26}
27#else
28static void *__memcpy(void *dest, const void *src, size_t n)
29{
30	long d0, d1, d2;
31	asm volatile(
32		"rep ; movsq\n\t"
33		"movq %4,%%rcx\n\t"
34		"rep ; movsb\n\t"
35		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
36		: "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src)
37		: "memory");
38
39	return dest;
40}
41#endif
42
43void *memset(void *s, int c, size_t n)
44{
45	int i;
46	char *ss = s;
47
48	for (i = 0; i < n; i++)
49		ss[i] = c;
50	return s;
51}
52
53void *memmove(void *dest, const void *src, size_t n)
54{
55	unsigned char *d = dest;
56	const unsigned char *s = src;
57
58	if (d <= s || d - s >= n)
59		return __memcpy(dest, src, n);
60
61	while (n-- > 0)
62		d[n] = s[n];
63
64	return dest;
65}
66
67/* Detect and warn about potential overlaps, but handle them with memmove. */
68void *memcpy(void *dest, const void *src, size_t n)
69{
70	if (dest > src && dest - src < n) {
71		warn("Avoiding potentially unsafe overlapping memcpy()!");
72		return memmove(dest, src, n);
73	}
74	return __memcpy(dest, src, n);
75}