Subversion Repositories or1k_old

/* Copyright (C) 1993, 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Brendan Kehoe <brendan@zen.org>, 1993.

   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.  */

/* __brk is a special syscall under Linux since it never returns an
   error.  Instead, the error condition is indicated by returning the old
   break value (instead of the new, requested one).  */

#include <features.h>
#define _ERRNO_H
#include <bits/errno.h>

#ifdef __PIC__
.section .bss
        .align 3
        .globl __curbrk
__curbrk: .skip 8
        .type __curbrk,@object
        .size __curbrk,8
#else
.comm __curbrk, 8
#endif

        .text
.globl  __brk;
.align 3;
.ent  __brk , 0;

__brk:
    .frame $30 ,   8 , $26
        ldgp    $29, 0($27)
        subq    $30, 8, $30
#ifdef PROF
        .set noat
        lda     AT, _mcount
        jsr     AT, (AT), _mcount
        .set at
#endif
        .prologue 1

        /* Save the requested brk across the system call.  */
        stq     $16, 0($30)

        ldiq    $0, __NR_brk
        call_pal 131

        ldq     $16, 0($30)

        /* Be prepared for an OSF-style brk.  */
        bne     $19, $err1
        beq     $0, $ok

        /* Correctly handle the brk(0) query case.  */
        cmoveq  $16, $0, $16
        xor     $16, $0, $1
        bne     $1, $err0

        /* Update __curbrk and return cleanly.  */
        mov     $31, $0
$ok:    stq     $16, __curbrk
        addq    $30, 8, $30
        ret

        /* What a horrible way to die.  */
$err0:  ldi     $0, ENOMEM
$err1:  addq    $30, 8, $30
        jmp     $31, __syscall_error

        .end __brk

.weak    brk;
    brk    =   __brk