xref: /openbsd-src/lib/libc/arch/amd64/gen/_setjmp.S (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1/*	$OpenBSD: _setjmp.S,v 1.3 2016/05/12 15:46:03 deraadt Exp $	*/
2/*	$NetBSD: _setjmp.S,v 1.1 2001/06/19 00:25:02 fvdl Exp $	*/
3
4/*
5 * Copyright (c) 2001 Wasabi Systems, Inc.
6 * All rights reserved.
7 *
8 * Written by Frank van der Linden for Wasabi Systems, Inc.
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. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *      This product includes software developed for the NetBSD Project by
21 *      Wasabi Systems, Inc.
22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23 *    or promote products derived from this software without specific prior
24 *    written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39
40#include <machine/asm.h>
41#include <machine/setjmp.h>
42
43	.hidden __jmpxor
44
45/*
46 * C library -- _setjmp, _longjmp
47 *
48 *	_longjmp(a,v)
49 * will generate a "return(v)" from the last call to
50 *	_setjmp(a)
51 * by restoring registers from the stack.
52 * The previous signal state is NOT restored.
53 */
54
55ENTRY(_setjmp)
56	movq    (%rsp),%r11
57	leaq	__jmpxor(%rip),%rcx
58	movq    %rbx,(_JB_RBX * 8)(%rdi)
59	movq	%rbp,%rax
60	xorq	(0*8)(%rcx),%rax
61	movq    %rax,(_JB_RBP * 8)(%rdi)
62	movq    %r12,(_JB_R12 * 8)(%rdi)
63	movq    %r13,(_JB_R13 * 8)(%rdi)
64	movq    %r14,(_JB_R14 * 8)(%rdi)
65	movq    %r15,(_JB_R15 * 8)(%rdi)
66	movq	%rsp,%rax
67	xorq	(1*8)(%rcx),%rax
68	movq    %rax,(_JB_RSP * 8)(%rdi)
69	movq	%r11,%rax
70	xorq	(2*8)(%rcx),%rax
71	movq    %rax,(_JB_PC  * 8)(%rdi)
72	xorq	%rcx,%rcx
73
74	xorq	%rax,%rax
75	ret
76END(_setjmp)
77
78ENTRY(_longjmp)
79	leaq	 __jmpxor(%rip),%rcx
80	movq    (_JB_RBX * 8)(%rdi),%rbx
81	movq    (_JB_RBP * 8)(%rdi),%r11
82	xorq    (0*8)(%rcx),%r11
83	movq	%r11,%rbp
84	movq    (_JB_R12 * 8)(%rdi),%r12
85	movq    (_JB_R13 * 8)(%rdi),%r13
86	movq    (_JB_R14 * 8)(%rdi),%r14
87	movq    (_JB_R15 * 8)(%rdi),%r15
88	movq    (_JB_RSP * 8)(%rdi),%r11
89	xorq	(1*8)(%rcx),%r11
90	movq	%r11,%rsp
91	movq    (_JB_PC  * 8)(%rdi),%r11
92	xorq	(2*8)(%rcx),%r11
93	xorq	%rcx,%rcx
94
95	movl	%esi,%eax
96	testl	%eax,%eax
97	jnz	1f
98	incl	%eax
991:	movq	%r11,0(%rsp)
100	ret
101END(_longjmp)
102