/*      $NetBSD: signalsphandler.S,v 1.1 2025/04/20 22:31:01 riastradh Exp $    */

/*-
* Copyright (c) 2025 The NetBSD Foundation, Inc.
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

#define _LOCORE

#include <machine/asm.h>

RCSID("$NetBSD: signalsphandler.S,v 1.1 2025/04/20 22:31:01 riastradh Exp $")

/*
* signalsphandler(signo@rdi)
*
*      Signal handler.  Store the stack pointer on entry at the global
*      variable signalsp and return.
*/
ENTRY(signalsphandler)
       /*
        * `The end of the input argument area shall be aligned on a
        *  [16-byte] boundary.  In other words, the value of (%rsp + 8)
        *  is always a multiple of 16 when control is transferred to
        *  the function entry point.'
        *
        * To make it convenient for t_signal_and_sp.c, we subtract 8
        * from %rsp in order to get something congruent to zero modulo
        * the stack alignemnt.
        */
       movq    %rsp,_C_LABEL(signalsp)(%rip)
       addq    $-8,_C_LABEL(signalsp)(%rip)
       ret
END(signalsphandler)