xref: /titanic_50/usr/src/lib/libc/i386/unwind/unwind_frame.s (revision 9a70fc3be3b1e966bf78825cdb8d509963a6f0a1)
17c478bd9Sstevel@tonic-gate/*
27c478bd9Sstevel@tonic-gate * CDDL HEADER START
37c478bd9Sstevel@tonic-gate *
47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5*9a70fc3bSMark J. Nelson * Common Development and Distribution License (the "License").
6*9a70fc3bSMark J. Nelson * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate *
87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate * and limitations under the License.
127c478bd9Sstevel@tonic-gate *
137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate *
197c478bd9Sstevel@tonic-gate * CDDL HEADER END
207c478bd9Sstevel@tonic-gate */
217c478bd9Sstevel@tonic-gate/*
227c478bd9Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
237c478bd9Sstevel@tonic-gate * Use is subject to license terms.
247c478bd9Sstevel@tonic-gate */
257c478bd9Sstevel@tonic-gate
26*9a70fc3bSMark J. Nelson	.file	"unwind_frame.s"
277c478bd9Sstevel@tonic-gate
287c478bd9Sstevel@tonic-gate#include <SYS.h>
297c478bd9Sstevel@tonic-gate
307c478bd9Sstevel@tonic-gate/* Cancellation/thr_exit() stuff */
317c478bd9Sstevel@tonic-gate
327c478bd9Sstevel@tonic-gate/*
337c478bd9Sstevel@tonic-gate * _ex_unwind_local(void)
347c478bd9Sstevel@tonic-gate *
357c478bd9Sstevel@tonic-gate * Called only from _t_cancel().
367c478bd9Sstevel@tonic-gate * Unwind two frames and invoke _t_cancel(fp) again.
377c478bd9Sstevel@tonic-gate *
387c478bd9Sstevel@tonic-gate * Before this the call stack is: f4 f3 f2 f1 _t_cancel
397c478bd9Sstevel@tonic-gate * After this the call stack is:  f4 f3 f2 _t_cancel
407c478bd9Sstevel@tonic-gate *	(as if "call f1" is replaced by "call _t_cancel(fp)" in f2)
417c478bd9Sstevel@tonic-gate */
427c478bd9Sstevel@tonic-gate
437c478bd9Sstevel@tonic-gate	ENTRY(_ex_unwind_local)
447c478bd9Sstevel@tonic-gate	movl	(%ebp), %edx		/ pop first frame [ back to f1() ]
457c478bd9Sstevel@tonic-gate	movl	(%edx), %ebp		/ pop second frame [ back to f2() ]
467c478bd9Sstevel@tonic-gate	movl	4(%edx), %eax		/ save f2's return pc
477c478bd9Sstevel@tonic-gate	movl	%eax, (%edx)		/ mov it up for one arg
487c478bd9Sstevel@tonic-gate	movl	%edx, %esp		/ stack pointer at ret addr
497c478bd9Sstevel@tonic-gate	movl	%ebp, 4(%esp)
507c478bd9Sstevel@tonic-gate	jmp	_t_cancel
517c478bd9Sstevel@tonic-gate	SET_SIZE(_ex_unwind_local)
527c478bd9Sstevel@tonic-gate
537c478bd9Sstevel@tonic-gate/*
547c478bd9Sstevel@tonic-gate * _ex_clnup_handler(void *arg, void  (*clnup)(void *))
557c478bd9Sstevel@tonic-gate *
567c478bd9Sstevel@tonic-gate * Called only from _t_cancel().
577c478bd9Sstevel@tonic-gate * Unwind one frame, call the cleanup handler with argument arg from the
587c478bd9Sstevel@tonic-gate * restored frame, then jump to _t_cancel(fp) again from the restored frame.
597c478bd9Sstevel@tonic-gate */
607c478bd9Sstevel@tonic-gate
617c478bd9Sstevel@tonic-gate	ENTRY(_ex_clnup_handler)
627c478bd9Sstevel@tonic-gate	pushl	%ebp			/ save current frame pointer
637c478bd9Sstevel@tonic-gate	pushl	8(%esp)			/ first argument [arg]
647c478bd9Sstevel@tonic-gate	movl	(%ebp), %ebp		/ pop out one frame
657c478bd9Sstevel@tonic-gate	call	*16(%esp)		/ call handler [clnup]
667c478bd9Sstevel@tonic-gate	addl	$4, %esp
677c478bd9Sstevel@tonic-gate	popl	%eax			/ old frame pointer
687c478bd9Sstevel@tonic-gate	lea	4(%eax), %esp		/ stk points to old frame
697c478bd9Sstevel@tonic-gate	movl	%ebp, 4(%esp)		/ _t_cancel() gets frame pointer arg
707c478bd9Sstevel@tonic-gate	jmp	_t_cancel
717c478bd9Sstevel@tonic-gate	SET_SIZE(_ex_clnup_handler)
727c478bd9Sstevel@tonic-gate
737c478bd9Sstevel@tonic-gate/*
747c478bd9Sstevel@tonic-gate * _thrp_unwind(void *arg)
757c478bd9Sstevel@tonic-gate *
767c478bd9Sstevel@tonic-gate * Ignore the argument; jump to _t_cancel(fp) with caller's fp
777c478bd9Sstevel@tonic-gate */
787c478bd9Sstevel@tonic-gate	ENTRY(_thrp_unwind)
797c478bd9Sstevel@tonic-gate	movl	%ebp, 4(%esp)
807c478bd9Sstevel@tonic-gate	jmp	_t_cancel
817c478bd9Sstevel@tonic-gate	SET_SIZE(_thrp_unwind)
82