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