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brk.S revision 1.23 
      1 /*	$NetBSD: brk.S,v 1.23 2013/09/12 15:36:15 joerg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * William Jolitz.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  *
     34  *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
     35  */
     36 
     37 #include <machine/asm.h>
     38 #if defined(SYSLIBC_SCCS) && !defined(lint)
     39 	RCSID("$NetBSD: brk.S,v 1.23 2013/09/12 15:36:15 joerg Exp $")
     40 #endif /* SYSLIBC_SCCS and not lint */
     41 
     42 #include "SYS.h"
     43 
     44 	.globl	_end
     45 	.globl	_C_LABEL(__minbrk)
     46 	.globl	CURBRK
     47 
     48 #ifdef WEAK_ALIAS
     49 WEAK_ALIAS(brk, _brk)
     50 #endif
     51 
     52 	.data
     53 _C_LABEL(__minbrk):
     54 	.long	_end
     55 	.text
     56 
     57 ENTRY(_brk)
     58 #ifdef __PIC__
     59 	movl	4(%esp),%ecx
     60 	PIC_PROLOGUE
     61 	movl	PIC_GOT(_C_LABEL(__minbrk)),%edx
     62 	PIC_EPILOGUE
     63 	cmpl	%ecx,(%edx)
     64 	jb	1f
     65 	movl	(%edx),%ecx
     66 	movl	%ecx,4(%esp)
     67 1:
     68 	OSYSTRAP(break)	/* don't clobber %ecx */
     69 	jc	err
     70 	PIC_PROLOGUE
     71 	movl	PIC_GOT(CURBRK),%edx	# set up GOT addressing
     72 	PIC_EPILOGUE
     73 	movl	%ecx,(%edx)
     74 	xorl	%eax,%eax
     75 	ret
     76 err:
     77 	jmp	CERROR
     78 #else
     79 	movl	4(%esp),%ecx
     80 	cmpl	%ecx,_C_LABEL(__minbrk)
     81 	jb	1f
     82 	movl	_C_LABEL(__minbrk),%ecx
     83 	movl	%ecx,4(%esp)
     84 1:
     85 	OSYSTRAP(break)	/* don't clobber %ecx */
     86 	jc	err
     87 	movl	%ecx,CURBRK
     88 	xorl	%eax,%eax
     89 	ret
     90 err:
     91 	jmp	CERROR
     92 #endif
     93