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/*
* Copyright (c) 2003 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the BSD
* License. This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY expressed or implied, including the implied
* warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. A copy
* of this license is available at http://www.opensource.org/licenses. Any
* Red Hat trademarks that are incorporated in the source code or documentation
* are not subject to the BSD License and may only be used or replicated with
* the express permission of Red Hat, Inc.
*/
#include <errno.h>
extern int __heap __far; /* beginning of heap */
extern int __heap_end __far; /* if at address 0, use stack pointer as limit */
static char *the_break = (char *)(& __heap);
int
is_addr_0 (int address)
{
return address ? 0 : 1;
}
void *
sbrk(int inc)
{
char *current_heap_limit = (char *) (& __heap_end);
/* is_addr_0 avoids optimizing out this block. */
if (is_addr_0 ((int) current_heap_limit))
{
int something;
int margin = 4096;
current_heap_limit = (char *) (& something) - margin;
}
if ((the_break + inc) < current_heap_limit)
{
void *rv = (void *) the_break;
the_break += inc;
return rv;
}
else
{
errno = ENOMEM;
return (void *) -1;
}
}
int
brk (void *ptr)
{
the_break = ptr;
return 0;
}
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