xref: /openbsd/lib/libc/arch/i386/gen/sigsetjmp.S (revision 4cfece93)
1/* $OpenBSD: sigsetjmp.S,v 1.10 2016/05/30 02:11:21 guenther Exp $ */
2/*-
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "SYS.h"
35
36	.global	__jmpxor
37
38ENTRY(sigsetjmp)
39	movl	4(%esp),%ecx
40	movl	8(%esp),%eax
41	movl	%eax,28(%ecx)
42	testl	%eax,%eax
43	jz	1f
44
45	pushl	$0			/* mask = empty */
46	pushl	$1			/* how = SIG_BLOCK */
47	subl	$4,%esp
48	movl	$(SYS_sigprocmask),%eax
49	int	$0x80			/* leave oset in %eax */
50	addl	$12,%esp
51	movl	%eax,24(%ecx)
52
531:	call	2f
542:	popl	%edx
55	addl	$__jmpxor-2b,%edx	# load cookie address
56
57	movl	%ebx, 4(%ecx)
58	movl	%esp,   %eax
59	xorl	8(%edx),%eax		# use esp cookie
60	movl	%eax, 8(%ecx)
61	movl	%ebp,   %eax
62	xorl	0(%edx),%eax		# use ebp cookie
63	movl	%eax,12(%ecx)
64	movl	%esi,16(%ecx)
65	movl	%edi,20(%ecx)
66	movl	4(%edx),%edx		# load eip cookie over cookie address
67	xorl	0(%esp),%edx
68	movl	%edx, 0(%ecx)
69	xorl	%eax,%eax
70	ret
71END(sigsetjmp)
72
73ENTRY(siglongjmp)
74	movl	4(%esp),%edx
75	cmpl	$0,28(%edx)
76	jz	1f
77
78	pushl	24(%edx)		/* mask from sc_mask */
79	pushl	$3			/* how = SIG_SETMASK */
80	subl	$4,%esp
81	movl	$(SYS_sigprocmask),%eax
82	int	$0x80
83	addl	$12,%esp
84
851:	call	2f
862:	popl	%ecx
87	addl	$__jmpxor-2b,%ecx	# load cookie address
88
89	movl	 4(%esp),%edx		# reload in case sigprocmask failed
90	movl	 8(%esp),%eax
91	movl	 4(%edx),%ebx
92	movl	 8(%edx),%esi		# load xor'ed esp into safe register
93	xorl	 8(%ecx),%esi		# use esp cookie
94	movl	   %esi, %esp		# un-xor'ed esp is safe to use
95	movl	12(%edx),%ebp
96	xorl	 0(%ecx),%ebp		# use ebp cookie
97	movl	16(%edx),%esi
98	movl	20(%edx),%edi
99
100	movl	 4(%ecx),%ecx		# load eip cookie over cookie address
101	xorl	 0(%edx),%ecx
102	testl	%eax,%eax
103	jnz	2f
104	incl	%eax
1052:	movl	%ecx,0(%esp)
106	ret
107END(siglongjmp)
108