/*      $OpenBSD: sigsetjmp.S,v 1.4 2023/12/10 16:45:52 deraadt 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>

#define JMP_sigflag     0x00
#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
#define JMP_sigmask   0xc8


        .extern __jmpxor

/* int sigsetjmp(sigjmp_buf env, int savemask) */
ENTRY(sigsetjmp)
        RETGUARD_SETUP(sigsetjmp, %r11)
        mr      %r5, %r3                /* save jmpbuf addr in r5 */
        std     %r4, JMP_sigflag(%r5)
        or.     %r4, %r4, %r4
        beq     1f
        li      %r3, 1                  /* how = SIG_BLOCK */
        li      %r4, 0                  /* oset = empty */
        li      %r0, SYS_sigprocmask
99:     sc
        PINSYSCALL(SYS_sigprocmask, 99b)
        nop
        std     %r3, JMP_sigmask(5)
1:
        addis   %r7, %r2, __jmpxor@toc@ha
        addi    %r7, %r7, __jmpxor@toc@l
        ld      %r8, 0(%r7)             /* xor for r1 */
        ld      %r7, 8(%r7)             /* xor for lr, overwrite addr */

        /*      r1, r14-r31 */
        xor     %r0, %r8, %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    %r0
        xor     %r7, %r0, %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)
        mfctr   %r0
        mfxer   %r0
        std     %r0, JMP_xer(%r5)
        /* f14-f31, fpscr */
        li %r3, 0
        RETGUARD_CHECK(sigsetjmp, %r11)
        blr
END(sigsetjmp)


/* int siglongjmp(sigjmp_buf env, int val) */
ENTRY(siglongjmp)
        mr      %r5, %r3                /* save jmpbuf addr in r5 */
        mr      %r6, %r4                /* save val in r6 */
        ld      %r4, JMP_sigflag(%r5)   /* do we need to restore sigmask? */
        or.     %r4, %r4, %r4
        beq     1f

        li      %r3, 3                  /* how = SIG_SETMASK */
        ld      %r4, JMP_sigmask(%r5)   /* oset from the jmpbuf */
        li      %r0, SYS_sigprocmask
98:     sc
        PINSYSCALL(SYS_sigprocmask, 98b)
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(siglongjmp, %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(siglongjmp, %r11)
        blr
END(siglongjmp)