xref: /openbsd-src/lib/libc/arch/arm/gen/setjmp.S (revision ef6a97f90fece7355463263fff12b2349b091299)
1/*	$OpenBSD: setjmp.S,v 1.8 2022/05/24 17:21:17 guenther Exp $	*/
2/*	$NetBSD: setjmp.S,v 1.5 2003/04/05 23:08:51 bjh21 Exp $	*/
3
4/*
5 * Copyright (c) 1997 Mark Brinicombe
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by Mark Brinicombe
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "SYS.h"
37#include <machine/setjmp.h>
38
39	.hidden	__jmpxor
40
41/*
42 * C library -- setjmp, longjmp
43 *
44 *	longjmp(a,v)
45 * will generate a "return(v)" from the last call to
46 *	setjmp(a)
47 * by restoring registers from the stack.
48 * The previous signal state is restored.
49 */
50
51ENTRY(setjmp)
52	/* Block all signals and retrieve the old signal mask */
53	mov	r2, r0
54	mov	r1, #0x00000000
55	mov	r0, #0x00000001			/* SIG_BLOCK */
56	SYSTRAP(sigprocmask)
57
58	/* Store signal mask */
59	str	r0, [r2, #(29 * 4)]
60
61	ldr	r1, .Lsetjmp_magic
62	str	r1, [r2], #4
63
64	ldr	r12, .L_jmpxor_setjmp
651:	add	r12, pc, r12			/* r12 = &__jmpxor */
66	ldr	r3, [r12], #4			/* r3 = __jmpxor[1] */
67	ldr	r12, [r12] 			/* r12 = __jmpxor[0] */
68	eor	r12, r13, r12			/* r12 = sp ^ __jmpxor[0] */
69	eor	r3, lr, r3			/* r3 = lr ^ __jmpxor[1] */
70
71#ifdef SOFTFLOAT
72	add	r2, r2, #68
73#else
74	/* Store fpcsr */
75	vmrs	r1, fpscr
76	str	r1, [r2], #4
77	/* Store fp registers */
78	vstmia	r2!, {d8-d15}
79#endif	/* SOFTFLOAT */
80	/* Store integer registers */
81	stmia	r2, {r3-r12}
82
83	mov	r0, #0x00000000
84	mov	r12, r0				/* overwrite __jmpxor copies */
85	mov	r3, r0
86	mov	pc, lr
87
88.Lsetjmp_magic:
89	.word	_JB_MAGIC_SETJMP
90.L_jmpxor_setjmp:
91	.word	__jmpxor - 1b
92END_STRONG(setjmp)
93
94
95ENTRY(longjmp)
96	ldr	r2, .Lsetjmp_magic
97	ldr	r3, [r0]
98	teq	r2, r3
99	bne	.Lbotch
100
101	/* Fetch signal mask and call sigprocmask */
102	mov	r3, r0				/* r3 = jmpbuf */
103	mov	r2, r1				/* r2 = retvalue */
104	ldr	r1, [r0, #(29 * 4)]
105	mov	r0, #0x00000003			/* SIG_SETMASK */
106	SYSTRAP(sigprocmask)
107
108	add	r3, r3, #4
109#ifdef SOFTFLOAT
110	add	r3, r3, #68
111#else
112	/* Restore fpcsr */
113	ldr	r4, [r3], #4
114	vmsr	fpscr, r4
115	/* Restore fp registers */
116	vldmia	r3!, {d8-d15}
117#endif	/* SOFTFLOAT */
118	/* Restore integer registers */
119	ldmia	r3, {r3-r12}
120
121	ldr	r0, .L_jmpxor_longjmp
1221:	add	r0, pc, r0		/* r0 = &__jmpxor */
123	ldr	lr, [r0], #4		/* lr = __jmpxor[1] */
124	eor	lr, r3, lr		/* lr ^= jmpbuf[LR] */
125	ldr	r0, [r0] 		/* r0 = __jmpxor[0] */
126	eor	r13, r0, r12		/* sp = __jmpxor[0] ^ jmpbuf[SP] */
127	mov	r12, r2			/* overwrite __jmpxor copies */
128	mov	r3, r2
129
130	/* Validate sp and lr */
131	teq	sp, #0
132	teqne	lr, #0
133	beq	.Lbotch
134
135	/* Set return value */
136	mov	r0, r12
137	teq	r0, #0x00000000
138	moveq	r0, #0x00000001
139	mov	pc, lr
140
141.L_jmpxor_longjmp:
142	.word	__jmpxor - 1b
143
144	/* validation failed, die die die. */
145.Lbotch:
146	bl	_HIDDEN(abort)
147	b	. - 8		/* Cannot get here */
148END_STRONG(longjmp)
149