42 lines
851 B
C
42 lines
851 B
C
/* libc/sys/linux/brk.c - Change data segment size */
|
|
|
|
/* Written 2000 by Werner Almesberger */
|
|
|
|
|
|
#include <stddef.h> /* for NULL */
|
|
#include <sys/types.h>
|
|
#include <sys/unistd.h>
|
|
#include <machine/syscall.h>
|
|
|
|
|
|
static char *curr_brk = NULL;
|
|
|
|
|
|
#define __NR___brk __NR_brk /* Linux brk ain't no brk(2) */
|
|
|
|
static _syscall1(void *,__brk,void *,end_data_segment)
|
|
|
|
|
|
int brk(void *end_data_segment)
|
|
{
|
|
char *new_brk;
|
|
|
|
new_brk = __brk(end_data_segment);
|
|
if (new_brk != end_data_segment) return -1;
|
|
curr_brk = new_brk;
|
|
return 0;
|
|
}
|
|
|
|
|
|
void *sbrk(ptrdiff_t increment) /* SHOULD be ptrdiff_t */
|
|
{
|
|
char *old_brk,*new_brk;
|
|
|
|
if (!curr_brk) curr_brk = __brk(NULL);
|
|
new_brk = __brk(curr_brk+increment);
|
|
if (new_brk != curr_brk+increment) return (void *) -1;
|
|
old_brk = curr_brk;
|
|
curr_brk = new_brk;
|
|
return old_brk;
|
|
}
|