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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/* See LICENSE file for copyright and license details. */
#include "libsimple.h"
#include "test.h"
#include <malloc.h>
size_t alloc_fail_in = 0;
static int custom_malloc = 0;
size_t
get_pagesize(void)
{
long r;
assert((r = sysconf(_SC_PAGESIZE)) >= 0);
return (size_t)r;
}
size_t
round_up(size_t size)
{
size_t ps = get_pagesize();
return size + (ps - size % ps) % ps;
}
int
have_custom_malloc(void)
{
free(malloc(1));
return custom_malloc;
}
struct allocinfo *
get_allocinfo(void *ptr)
{
assert(ptr);
return (void *)((char *)ptr - sizeof(struct allocinfo));
}
void *
malloc(size_t size)
{
size_t alignment = get_pagesize();
while (alignment < sizeof(long long int))
alignment *= 2;
while (alignment < sizeof(long double))
alignment *= 2;
return memalign(alignment, size);
}
void *
calloc(size_t nelem, size_t elsize)
{
struct allocinfo *info;
void *ret;
assert(nelem && elsize); /* unspecified behaviour otherwise */
if (nelem > SIZE_MAX / elsize) {
errno = ENOMEM;
return NULL;
}
ret = malloc(nelem * elsize);
if (!ret)
return NULL;
memset(ret, 0, nelem * elsize);
info = get_allocinfo(ret);
info->zeroed = nelem * elsize;
return ret;
}
void *
realloc(void *ptr, size_t size)
{
struct allocinfo *info;
void *ret;
size_t n;
assert(size); /* unspecified behaviour otherwise */
if (!ptr)
return malloc(size);
ret = malloc(size);
if (!ret)
return malloc;
info = get_allocinfo(ret);
n = MIN(size, info->size);
info->zeroed = MIN(n, info->zeroed);
memcpy(ret, ptr, n);
free(ptr);
return ret;
}
void *
memalign(size_t alignment, size_t size)
{
struct allocinfo *info;
void *ptr;
size_t n;
uintptr_t off;
custom_malloc = 1;
assert(alignment);
assert(!(alignment & (alignment - 1UL)));
assert(size); /* unspecified behaviour otherwise */
if (alloc_fail_in && alloc_fail_in-- == 1)
goto enomem;
n = size;
if (n > SIZE_MAX - alignment)
goto enomem;
n += alignment;
if (n > SIZE_MAX - sizeof(struct allocinfo))
goto enomem;
n += sizeof(struct allocinfo);
ptr = mmap(NULL, n, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (!ptr)
goto enomem;
off = (uintptr_t)ptr;
off += sizeof(struct allocinfo);
off += (alignment - off % alignment) % alignment;
off -= (uintptr_t)ptr;
ptr = (char *)ptr + off;
info = get_allocinfo(ptr);
info->real_beginning = (char *)ptr - off;
info->real_size = n;
info->size = size;
info->extent = n - size - off;
info->alignment = alignment;
info->zeroed = 0;
info->refcount = 1;
return ptr;
enomem:
errno = ENOMEM;
return NULL;
}
int
posix_memalign(void **memptr, size_t alignment, size_t size)
{
int ret, saved_errno = errno;
void **volatile ptrp = memptr;
assert(!(alignment % sizeof(void *)));
assert(ptrp);
*memptr = memalign(alignment, size);
ret = *memptr ? ENOMEM : 0;
errno = saved_errno;
return ret;
}
void *
aligned_alloc(size_t alignment, size_t size)
{
assert(alignment);
assert(!(size % alignment));
return memalign(alignment, size);
}
void *
valloc(size_t size)
{
return memalign(get_pagesize(), size);
}
void *
pvalloc(size_t size)
{
return memalign(get_pagesize(), round_up(size));
}
void
free(void *ptr)
{
struct allocinfo *info;
if (!ptr)
return;
info = get_allocinfo(ptr);
assert(info->refcount);
if (info->refcount-- > 1)
return;
assert(!munmap(info->real_beginning, info->real_size));
}
|
