root/sys/platform/pc64/x86_64/sigtramp.s
/*-
 * Copyright (c) 2003 Peter Wemm <peter@freeBSD.org>
 * 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 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/amd64/amd64/sigtramp.S,v 1.1 2003/05/01 01:05:21 peter Exp $
 */

#include <sys/syscall.h>

#include <machine/asmacros.h>

#include "assym.s"

        .text
/**********************************************************************
 *
 * Signal trampoline, copied to top of user stack
 *
 * arguments: %rdi, %rsi, %rdx, %rcx
 */
NON_GPROF_ENTRY(sigcode)
        call    *SIGF_HANDLER(%rsp)     /* call signal handler */
        lea     SIGF_UC(%rsp),%rdi      /* get ucontext_t */
        pushq   $0                      /* junk to fake return addr. */
        movq    $SYS_sigreturn,%rax
        syscall                         /* enter kernel with args */
0:      hlt                             /* trap priviliged instruction */
        jmp     0b

        ALIGN_TEXT
esigcode:

        .data
        .globl  szsigcode
szsigcode:
        .long   esigcode-sigcode