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/* $OpenBSD: setjmp.S,v 1.4 2020/10/18 17:51:39 mortimer Exp $ */
/*
* Copyright (c) 2020 Dale Rahn. All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "SYS.h"
#include <machine/asm.h>
/* int setjmp(jmp_buf env) */
#define JMP_r1 0x08
#define JMP_r14 0x10
#define JMP_r15 0x18
#define JMP_r16 0x20
#define JMP_r17 0x28
#define JMP_r18 0x30
#define JMP_r19 0x38
#define JMP_r20 0x40
#define JMP_r21 0x48
#define JMP_r22 0x50
#define JMP_r23 0x58
#define JMP_r24 0x60
#define JMP_r25 0x68
#define JMP_r26 0x70
#define JMP_r27 0x78
#define JMP_r28 0x80
#define JMP_r29 0x88
#define JMP_r30 0x90
#define JMP_r31 0x98
#define JMP_lr 0xa0
#define JMP_cr 0xa8
#define JMP_ctr 0xb0
#define JMP_xer 0xb8
#define JMP_sig 0xc0
.section .openbsd.randomdata,"aw",@progbits
.balign 4
.globl __jmpxor
.hidden __jmpxor
__jmpxor:
.zero 8*2 # (r1, lr)
END(__jmpxor)
.type __jmpxor,@object
/* int setjmp(jmp_buf env); */
ENTRY(setjmp)
mr %r5, %r3 /* save jmpbuf addr in r5 */
li %r3, 1 /* how = SIG_BLOCK */
li %r4, 0 /* oset = empty */
li %r0, SYS_sigprocmask
sc
std %r3, JMP_sig(%r5)
b 1f
nop
ENTRY(_setjmp)
mr %r5, %r3 /* save jmpbuf addr in r5 */
1:
RETGUARD_SETUP(setjmp, %r11)
addis %r7, %r2, __jmpxor@toc@ha
addi %r7, %r7, __jmpxor@toc@l
ld %r0, 0(%r7) /* xor for r1 */
ld %r7, 8(%r7) /* xor for lr, overwrite addr */
/* r1, r14-r31 */
xor %r0, %r0, %r1 /* use and overwrite the r1 xor */
std %r0, JMP_r1(%r5)
std %r14, JMP_r14(%r5)
std %r15, JMP_r15(%r5)
std %r16, JMP_r16(%r5)
std %r17, JMP_r17(%r5)
std %r18, JMP_r18(%r5)
std %r19, JMP_r19(%r5)
std %r20, JMP_r20(%r5)
std %r21, JMP_r21(%r5)
std %r22, JMP_r22(%r5)
std %r23, JMP_r23(%r5)
std %r24, JMP_r24(%r5)
std %r25, JMP_r25(%r5)
std %r26, JMP_r26(%r5)
std %r27, JMP_r27(%r5)
std %r28, JMP_r28(%r5)
std %r29, JMP_r29(%r5)
std %r30, JMP_r30(%r5)
std %r31, JMP_r31(%r5)
/* lr, cr, ctr, xer */
mflr %r6
xor %r7, %r6, %r7 /* use and overwrite the lr xor */
std %r7, JMP_lr(%r5)
mfcr %r0
std %r0, JMP_cr(%r5)
mfctr %r0
std %r0, JMP_ctr(%r5)
mfxer %r0
std %r0, JMP_xer(%r5)
/* floating point is all caller save */
li %r3, 0
RETGUARD_CHECK(setjmp, %r11)
blr
END(_setjmp)
END(setjmp)
/* void longjmp(jmp_buf env, int val); */
ENTRY(longjmp)
mr %r5, %r3 /* save jmpbuf addr in r5 */
mr %r6, %r4 /* save val in r6 */
li %r3, 3 /* how = SIG_SETMASK */
ld %r4, JMP_sig(%r5) /* oset from the jmpbuf */
li %r0, SYS_sigprocmask
sc
nop
b 1f
nop
/* _longjmp(jmp_buf env, int val); */
ENTRY(_longjmp)
mr %r5, %r3 /* save jmpbuf addr in r5 */
mr %r6, %r4 /* save val in r6 */
1:
addis %r9, %r2, __jmpxor@toc@ha
addi %r9, %r9, __jmpxor@toc@l
ld %r8, 0(%r9) /* xor for r1 */
ld %r9, 8(%r9) /* xor for lr, overwrite addr */
ld %r0, JMP_lr(%r5)
xor %r0, %r0, %r9 /* use the lr xor */
mtlr %r0
RETGUARD_SETUP(longjmp, %r11)
/* r1, r14-r31 */
ld %r0, JMP_r1(%r5)
xor %r1, %r0, %r8 /* use the r1 xor */
ld %r14, JMP_r14(%r5)
ld %r15, JMP_r15(%r5)
ld %r16, JMP_r16(%r5)
ld %r17, JMP_r17(%r5)
ld %r18, JMP_r18(%r5)
ld %r19, JMP_r19(%r5)
ld %r20, JMP_r20(%r5)
ld %r21, JMP_r21(%r5)
ld %r22, JMP_r22(%r5)
ld %r23, JMP_r23(%r5)
ld %r24, JMP_r24(%r5)
ld %r25, JMP_r25(%r5)
ld %r26, JMP_r26(%r5)
ld %r27, JMP_r27(%r5)
ld %r28, JMP_r28(%r5)
ld %r29, JMP_r29(%r5)
ld %r30, JMP_r30(%r5)
ld %r31, JMP_r31(%r5)
/* cr, lr, ctr, xer */
ld %r8, JMP_cr(%r5) /* overwrite the r1 xor */
mtcr %r8
ld %r9, JMP_ctr(%r5) /* overwrite the lr xor */
mtctr %r9
ld %r0, JMP_xer(%r5)
mtxer %r0
/* floating point is all caller save */
/* if return val in r6 == 0, return 1, not 0 */
mr %r3, %r6
cmpwi %r6, 0
bne 2f
li %r3, 1
2:
RETGUARD_CHECK(longjmp, %r11)
blr
END(_longjmp)
END(longjmp)
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