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
|
/* Copyright (C) 1995-1997 Robert de Bath <rdebath@cix.compulink.co.uk>
* This file is part of the Linux-8086 C library and is distributed
* under the GNU Library General Public License.
*/
#include <errno.h>
/****************************************************************************/
#if defined(__GNUC__) && defined(__i386__)
extern char * __brk_addr;
extern char * __brk();
#ifdef L___brk_addr
char * __brk_addr = 0; /* This holds the current return for sbrk(0) */
/* "mov %ebx,4(%esp),%ebx\n\t" "mov $45,%eax\n\t" */
char *
__brk(char * val)
{
char * retval;
__asm__(
"int $0x80"
: "=a" (retval)
: "0" (45), "b" (val)
);
return retval;
}
__brk_addr_init()
{
if( __brk_addr == 0 && (__brk_addr = __brk(0)) == 0 )
{
errno = ENOMEM;
return -1;
}
return 0;
}
#endif
#ifdef L_sbrk
char *
sbrk(brk_off)
int brk_off;
{
char * new_brk;
if( __brk_addr_init() ) return (char*)-1;
if( brk_off == 0 ) return __brk_addr;
new_brk = __brk_addr + brk_off;
__brk_addr = __brk(new_brk);
if( __brk_addr != new_brk )
{
errno = ENOMEM;
return (char*)-1;
}
return __brk_addr - brk_off;
}
#endif
#ifdef L_brk
int
brk(new_brk)
char * new_brk;
{
if( __brk_addr_init() ) return -1;
__brk_addr = __brk(new_brk);
if( __brk_addr == new_brk ) return 0;
errno = ENOMEM;
return -1;
}
#endif
#endif
|
