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/* $NetBSD: __sigtramp2.S,v 1.5 2021/11/21 23:58:09 thorpej Exp $ */
/*-
* Copyright (c) 2003 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.
*/
#include "SYS.h"
#include "assym.h"
/*
* The m68k signal trampoline is invoked only to return from
* the signal; the kernel calls the signal handler directly.
*
* On entry, stack looks like:
*
* ucontext structure [12+sizeof(siginfo_t)]
* siginfo structure [12]
* pointer to ucontext structure [8]
* pointer to siginfo structure [4]
* sp-> signal number [0]
*
* The DWARF register numbers are 0-7 (dX), 8-15 (aX), 16-23 (fpX),
* which maps nicely to _REG_D[0-7] and _REG_A[0-7]. For m68k, there
* is a DWARF pseudo-register for the return address, and additionally
* another DWARF pseudo-register for signal handler return addresses.
* We will specify both return address pseudo-registers (without
* explicitly specifying .cfi_return_column) to keep the compiler
* run-time happy with whichever one it decides to use.
*/
#define DWARF_RETURN_REG 24
#if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
#define DWARF_SIGRETURN_REG __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
#else
#define DWARF_SIGRETURN_REG 25
#endif
#define CFI_OFFSET_DWARF_REG(d, r) .cfi_offset d, r * 4
#define CFI_OFFSET(r) CFI_OFFSET_DWARF_REG(r, r)
.text
.cfi_startproc simple
.cfi_signal_frame
.cfi_def_cfa _REG_A7, 12 + SIZEOF_SIGINFO + UC_GREGS
CFI_OFFSET(_REG_D0)
CFI_OFFSET(_REG_D1)
CFI_OFFSET(_REG_D2)
CFI_OFFSET(_REG_D3)
CFI_OFFSET(_REG_D4)
CFI_OFFSET(_REG_D5)
CFI_OFFSET(_REG_D6)
CFI_OFFSET(_REG_D7)
CFI_OFFSET(_REG_A0)
CFI_OFFSET(_REG_A1)
CFI_OFFSET(_REG_A2)
CFI_OFFSET(_REG_A3)
CFI_OFFSET(_REG_A4)
CFI_OFFSET(_REG_A5)
CFI_OFFSET(_REG_A6)
CFI_OFFSET(_REG_A7)
CFI_OFFSET_DWARF_REG(DWARF_RETURN_REG, _REG_PC)
CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC)
/*
* The unwind entry includes one instruction slot prior to the trampoline
* because the unwinder will look up to (return PC - 1 insn) while unwinding.
* Normally this would be the jump / branch, but since there isn't one in
* this case, we place an explicit nop there instead.
*/
nop
ENTRY_NOPROFILE(__sigtramp_siginfo_2)
movl 8(%sp),%a0 /* get pointer to ucontext */
movl %a0,4(%sp) /* put it in the argument slot */
/* fake return address already there */
SYSTRAP(setcontext)
movl %d0,4(%sp) /* error code */
SYSTRAP(exit) /* exit */
.cfi_endproc
END(__sigtramp_siginfo_2)
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