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/* brk system call for Linux/VAX.
Copyright (C) 2000, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <unistd.h>
#include <sys/syscall.h>
/* This must be initialized data because commons can't have aliases. */
extern void *__curbrk;
libc_hidden_proto(__curbrk)
void *__curbrk = NULL;
libc_hidden_data_def(__curbrk)
libc_hidden_proto(brk)
int
brk (void *addr)
{
register unsigned long int result __asm__ ("%%r0");
__asm__ (
" pushl %%ap \n" /* Start frame */
" pushl %2 \n" /* New top address we wish to get */
" pushl $1 \n" /* One argument */
" movl %%sp, %%ap \n" /* Finish frame */
" chmk %1 \n" /* Perform the system call */
" addl2 $8, %%sp \n" /* Remove pushed arg */
" movl (%%sp)+, %%ap \n" /* Get back %AP */
: "=r" (result)
: "0" (__NR_brk),
"g" (addr));
if ((void *) result < addr) {
__set_errno (ENOMEM);
return -1;
} else
__curbrk = (void *) result;
return 0;
}
libc_hidden_def(brk)
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