xref: /illumos-gate/usr/src/lib/libc/amd64/gen/setjmp.S (revision 5d9d9091f564c198a760790b0bfa72c44e17912b)
1*5d9d9091SRichard Lowe/*
2*5d9d9091SRichard Lowe * CDDL HEADER START
3*5d9d9091SRichard Lowe *
4*5d9d9091SRichard Lowe * The contents of this file are subject to the terms of the
5*5d9d9091SRichard Lowe * Common Development and Distribution License (the "License").
6*5d9d9091SRichard Lowe * You may not use this file except in compliance with the License.
7*5d9d9091SRichard Lowe *
8*5d9d9091SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*5d9d9091SRichard Lowe * or http://www.opensolaris.org/os/licensing.
10*5d9d9091SRichard Lowe * See the License for the specific language governing permissions
11*5d9d9091SRichard Lowe * and limitations under the License.
12*5d9d9091SRichard Lowe *
13*5d9d9091SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each
14*5d9d9091SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*5d9d9091SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the
16*5d9d9091SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying
17*5d9d9091SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner]
18*5d9d9091SRichard Lowe *
19*5d9d9091SRichard Lowe * CDDL HEADER END
20*5d9d9091SRichard Lowe */
21*5d9d9091SRichard Lowe
22*5d9d9091SRichard Lowe/*
23*5d9d9091SRichard Lowe * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
24*5d9d9091SRichard Lowe * Use is subject to license terms.
25*5d9d9091SRichard Lowe */
26*5d9d9091SRichard Lowe
27*5d9d9091SRichard Lowe	.file	"setjmp.s"
28*5d9d9091SRichard Lowe
29*5d9d9091SRichard Lowe/*
30*5d9d9091SRichard Lowe *	longjmp(env, val)
31*5d9d9091SRichard Lowe * will generate a "return(val)" from
32*5d9d9091SRichard Lowe * the last call to
33*5d9d9091SRichard Lowe *	setjmp(env)
34*5d9d9091SRichard Lowe * by restoring registers rip rsp rbp rbx r12 r13 r14 r15 from 'env'
35*5d9d9091SRichard Lowe * and doing a return.
36*5d9d9091SRichard Lowe */
37*5d9d9091SRichard Lowe
38*5d9d9091SRichard Lowe/*
39*5d9d9091SRichard Lowe * entry    reg   offset
40*5d9d9091SRichard Lowe * env[0] = %rbx  0	register variables
41*5d9d9091SRichard Lowe * env[1] = %r12  8
42*5d9d9091SRichard Lowe * env[2] = %r13  16
43*5d9d9091SRichard Lowe * env[3] = %r14  24
44*5d9d9091SRichard Lowe * env[4] = %r15  32
45*5d9d9091SRichard Lowe * env[5] = %rbp  40	stack frame
46*5d9d9091SRichard Lowe * env[6] = %rsp  48
47*5d9d9091SRichard Lowe * env[7] = %rip  56
48*5d9d9091SRichard Lowe */
49*5d9d9091SRichard Lowe
50*5d9d9091SRichard Lowe#include <sys/asm_linkage.h>
51*5d9d9091SRichard Lowe#include <../assym.h>
52*5d9d9091SRichard Lowe
53*5d9d9091SRichard Lowe	ANSI_PRAGMA_WEAK(setjmp,function)
54*5d9d9091SRichard Lowe	ANSI_PRAGMA_WEAK(longjmp,function)
55*5d9d9091SRichard Lowe
56*5d9d9091SRichard Lowe	ENTRY(setjmp)
57*5d9d9091SRichard Lowe	movq	%rbx, 0(%rdi)
58*5d9d9091SRichard Lowe	movq	%r12, 8(%rdi)
59*5d9d9091SRichard Lowe	movq	%r13, 16(%rdi)
60*5d9d9091SRichard Lowe	movq	%r14, 24(%rdi)
61*5d9d9091SRichard Lowe	movq	%r15, 32(%rdi)
62*5d9d9091SRichard Lowe	movq	%rbp, 40(%rdi)
63*5d9d9091SRichard Lowe	popq	%rdx		/* return address */
64*5d9d9091SRichard Lowe	movq	%rsp, 48(%rdi)
65*5d9d9091SRichard Lowe	movq	%rdx, 56(%rdi)
66*5d9d9091SRichard Lowe
67*5d9d9091SRichard Lowe	movq	%fs:UL_SIGLINK, %rax
68*5d9d9091SRichard Lowe	xorq	%rcx, %rcx
69*5d9d9091SRichard Lowe	testq	%rax, %rax	/* are we in a signal handler? */
70*5d9d9091SRichard Lowe	jnz	1f
71*5d9d9091SRichard Lowe	incq	%rcx		/* no, tell longjmp to clear ul_siglink */
72*5d9d9091SRichard Lowe1:	orq	%rcx, 48(%rdi)	/* low-order 1-bit flag in the saved %rsp */
73*5d9d9091SRichard Lowe
74*5d9d9091SRichard Lowe	xorl	%eax, %eax	/* return 0 */
75*5d9d9091SRichard Lowe	jmp	*%rdx
76*5d9d9091SRichard Lowe	SET_SIZE(setjmp)
77*5d9d9091SRichard Lowe
78*5d9d9091SRichard Lowe	ENTRY(longjmp)
79*5d9d9091SRichard Lowe	movq	0(%rdi), %rbx
80*5d9d9091SRichard Lowe	movq	8(%rdi), %r12
81*5d9d9091SRichard Lowe	movq	16(%rdi), %r13
82*5d9d9091SRichard Lowe	movq	24(%rdi), %r14
83*5d9d9091SRichard Lowe	movq	32(%rdi), %r15
84*5d9d9091SRichard Lowe	movq	40(%rdi), %rbp
85*5d9d9091SRichard Lowe
86*5d9d9091SRichard Lowe	movq	48(%rdi), %rax	/* test low-order bit in the saved %rsp */
87*5d9d9091SRichard Lowe	testq	$1, %rax
88*5d9d9091SRichard Lowe	jz	1f
89*5d9d9091SRichard Lowe	xorq	%rcx, %rcx	/* if set, clear ul_siglink */
90*5d9d9091SRichard Lowe	movq	%rcx, %fs:UL_SIGLINK
91*5d9d9091SRichard Lowe	subq	$1, %rax	/* clear the flag bit */
92*5d9d9091SRichard Lowe1:	movq	%rax, %rsp
93*5d9d9091SRichard Lowe
94*5d9d9091SRichard Lowe	movl	%esi, %eax
95*5d9d9091SRichard Lowe	test	%eax, %eax	/* if val != 0		*/
96*5d9d9091SRichard Lowe	jnz	1f		/* 	return val	*/
97*5d9d9091SRichard Lowe	incl	%eax		/* else return 1	*/
98*5d9d9091SRichard Lowe1:
99*5d9d9091SRichard Lowe	movq	56(%rdi), %rdx	/* return to caller of setjmp */
100*5d9d9091SRichard Lowe	jmp	*%rdx
101*5d9d9091SRichard Lowe	SET_SIZE(longjmp)
102