root/lib/libc/arch/i386/gen/sigsetjmp.S
/* $OpenBSD: sigsetjmp.S,v 1.14 2023/12/10 16:45:51 deraadt Exp $ */
/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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/setjmp.h>

        .global __jmpxor

ENTRY(sigsetjmp)
        movl    4(%esp),%ecx            # parameter, pointer to env
        movl    8(%esp),%eax            # parameter, savemask
        movl    %eax,(_JB_SIGFLAG * 4)(%ecx)
        testl   %eax,%eax
        jz      1f

        pushl   $0                      /* mask = empty */
        pushl   $1                      /* how = SIG_BLOCK */
        subl    $4,%esp
        movl    $(SYS_sigprocmask),%eax
99:     int     $0x80                   /* leave oset in %eax */
        PINSYSCALL(SYS_sigprocmask, 99b)
        addl    $12,%esp
        movl    %eax,(_JB_SIGMASK * 4)(%ecx)

1:      call    2f
2:      popl    %edx
        addl    $__jmpxor-2b,%edx       # load cookie address

        movl    %ebx,(_JB_EBX * 4)(%ecx)
        movl    %esp,%eax
        xorl    8(%edx),%eax            # use esp cookie
        movl    %eax,(_JB_ESP * 4)(%ecx)
        movl    %ebp,%eax
        xorl    0(%edx),%eax            # use ebp cookie
        movl    %eax,(_JB_EBP * 4)(%ecx)
        movl    %esi,(_JB_ESI * 4)(%ecx)
        movl    %edi,(_JB_EDI * 4)(%ecx)
        movl    4(%edx),%edx            # load eip cookie over cookie address
        xorl    0(%esp),%edx
        movl    %edx,(_JB_EIP * 4)(%ecx)
        fnstcw  (_JB_FCW * 4)(%ecx)
        xorl    %eax,%eax
        ret
END(sigsetjmp)

ENTRY(siglongjmp)
        movl    4(%esp),%edx            # parameter, pointer to env
        cmpl    $0,(_JB_SIGFLAG * 4)(%edx)
        jz      1f

        pushl   (_JB_SIGMASK * 4)(%edx) /* mask from sc_mask */
        pushl   $3                      /* how = SIG_SETMASK */
        subl    $4,%esp
        movl    $(SYS_sigprocmask),%eax
98:     int     $0x80
        PINSYSCALL(SYS_sigprocmask, 98b)
        addl    $12,%esp

1:      call    2f
2:      popl    %ecx
        addl    $__jmpxor-2b,%ecx       # load cookie address

        movl    4(%esp),%edx            # reload in case sigprocmask failed
        movl    8(%esp),%eax            # parameter, val
        fldcw   (_JB_FCW * 4)(%edx)
        movl    (_JB_EBX * 4)(%edx),%ebx
        movl    (_JB_ESP * 4)(%edx),%esi
        xorl    8(%ecx),%esi            # use esp cookie
        movl    %esi,%esp               # un-xor'ed esp is safe to use
        movl    (_JB_EBP * 4)(%edx),%ebp
        xorl    0(%ecx),%ebp            # use ebp cookie
        movl    (_JB_ESI * 4)(%edx),%esi
        movl    (_JB_EDI * 4)(%edx),%edi

        movl    4(%ecx),%ecx            # load eip cookie over cookie address
        xorl    (_JB_EIP * 4)(%edx),%ecx
        testl   %eax,%eax
        jnz     2f
        incl    %eax
2:      movl    %ecx,0(%esp)
        ret
END(siglongjmp)