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
| | #include <stdlib.h>
#include <stdint.h>
#include <limits.h>
#include <errno.h>
#include "libc.h"
#define ALIGN 16
void *__expand_heap(size_t *);
static void *__simple_malloc(size_t n)
{
static char *cur, *end;
static volatile int lock[2];
size_t align=1, pad;
void *p;
if (!n) n++;
while (align<n && align<ALIGN)
align += align;
LOCK(lock);
pad = -(uintptr_t)cur & align-1;
if (n <= SIZE_MAX/2 + ALIGN) n += pad;
if (n > end-cur) {
size_t m = n;
char *new = __expand_heap(&m);
if (!new) {
UNLOCK(lock);
return 0;
}
if (new != end) {
cur = new;
n -= pad;
pad = 0;
}
end = new + m;
}
p = cur + pad;
cur += n;
UNLOCK(lock);
return p;
}
weak_alias(__simple_malloc, malloc);
weak_alias(__simple_malloc, __malloc0);
|