1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
/*
* This file is part of the libpayload project.
*
* It has originally been taken from the HelenOS project
* (http://www.helenos.eu), and slightly modified for our purposes.
*
* Copyright (c) 2005 Martin Decky
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <libpayload.h>
static void *default_memset(void *const s, const int c, size_t n)
{
size_t i;
u8 *dst = s;
unsigned long w = c & 0xff;
const u8 *const aligned_start =
(const u8 *)ALIGN_UP((uintptr_t)dst, sizeof(unsigned long));
for (; n > 0 && dst != aligned_start; --n, ++dst)
*dst = (u8)c;
for (i = 1; i < sizeof(unsigned long); i <<= 1)
w = (w << (i * 8)) | w;
for (i = 0; i < n / sizeof(unsigned long); i++)
((unsigned long *)dst)[i] = w;
dst += i * sizeof(unsigned long);
for (i = 0; i < n % sizeof(unsigned long); i++)
dst[i] = (u8)c;
return s;
}
void *memset(void *s, int c, size_t n)
__attribute__((weak, alias("default_memset")));
static void *default_memcpy(void *dst, const void *src, size_t n)
{
size_t i;
void *ret = dst;
if (IS_ALIGNED((uintptr_t)dst, sizeof(unsigned long)) &&
IS_ALIGNED((uintptr_t)src, sizeof(unsigned long))) {
for (i = 0; i < n / sizeof(unsigned long); i++)
((unsigned long *)dst)[i] = ((unsigned long *)src)[i];
src += i * sizeof(unsigned long);
dst += i * sizeof(unsigned long);
n -= i * sizeof(unsigned long);
}
for (i = 0; i < n; i++)
((u8 *)dst)[i] = ((u8 *)src)[i];
return ret;
}
void *memcpy(void *dst, const void *src, size_t n)
__attribute__((weak, alias("default_memcpy")));
static void *default_memmove(void *dst, const void *src, size_t n)
{
size_t offs;
ssize_t i;
if (src > dst)
return memcpy(dst, src, n);
if (!IS_ALIGNED((uintptr_t)dst, sizeof(unsigned long)) ||
!IS_ALIGNED((uintptr_t)src, sizeof(unsigned long))) {
for (i = n - 1; i >= 0; i--)
((u8 *)dst)[i] = ((u8 *)src)[i];
return dst;
}
offs = n - (n % sizeof(unsigned long));
for (i = (n % sizeof(unsigned long)) - 1; i >= 0; i--)
((u8 *)dst)[i + offs] = ((u8 *)src)[i + offs];
for (i = n / sizeof(unsigned long) - 1; i >= 0; i--)
((unsigned long *)dst)[i] = ((unsigned long *)src)[i];
return dst;
}
void *memmove(void *dst, const void *src, size_t n)
__attribute__((weak, alias("default_memmove")));
/**
* Compare two memory areas.
*
* @param s1 Pointer to the first area to compare.
* @param s2 Pointer to the second area to compare.
* @param n Size of the first area in bytes (both must have the same length).
* @return If n is 0, return zero. Otherwise, return a value less than, equal
* to, or greater than zero if s1 is found less than, equal to, or
* greater than s2 respectively.
*/
static int default_memcmp(const void *s1, const void *s2, size_t n)
{
size_t i = 0;
const unsigned long *w1 = s1, *w2 = s2;
if (IS_ALIGNED((uintptr_t)s1, sizeof(unsigned long)) &&
IS_ALIGNED((uintptr_t)s2, sizeof(unsigned long)))
for (; i < n / sizeof(unsigned long); i++)
if (w1[i] != w2[i])
break; /* fall through to find differing byte */
for (i *= sizeof(unsigned long); i < n; i++)
if (((u8 *)s1)[i] != ((u8 *)s2)[i])
return ((u8 *)s1)[i] - ((u8 *)s2)[i];
return 0;
}
int memcmp(const void *s1, const void *s2, size_t n)
__attribute__((weak, alias("default_memcmp")));
void *memchr(const void *s, int c, size_t n)
{
unsigned char *p = (unsigned char *)s;
while (n--)
if (*p != (unsigned char)c)
p++;
else
return p;
return 0;
}
|
