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/* $NetBSD: __sigtramp2.S,v 1.7 2021/11/23 02:49:56 thorpej Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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 ARM64 signal trampoline is invoked only to return from
* the signal; the kernel calls the signal handler directly.
*
* On entry, the stack looks like:
*
* ucontext structure
* sp-> siginfo structure
* and x28 points to the ucontext
*
* A DWARF pseudo-register is used for the return address from the
* signal trampoline.
*/
#if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
#define DWARF_SIGRETURN_REG __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
#else
#define DWARF_SIGRETURN_REG 96
#endif
#define CFI_OFFSET_DWARF_REG(d, r) .cfi_offset d, r * 8
#define CFI_OFFSET(r) CFI_OFFSET_DWARF_REG(r, r)
.text
.cfi_startproc simple
.cfi_signal_frame
.cfi_def_cfa _REG_X28, _UC_GREGS
CFI_OFFSET(_REG_X0)
CFI_OFFSET(_REG_X1)
CFI_OFFSET(_REG_X2)
CFI_OFFSET(_REG_X3)
CFI_OFFSET(_REG_X4)
CFI_OFFSET(_REG_X5)
CFI_OFFSET(_REG_X6)
CFI_OFFSET(_REG_X7)
CFI_OFFSET(_REG_X8)
CFI_OFFSET(_REG_X9)
CFI_OFFSET(_REG_X10)
CFI_OFFSET(_REG_X11)
CFI_OFFSET(_REG_X12)
CFI_OFFSET(_REG_X13)
CFI_OFFSET(_REG_X14)
CFI_OFFSET(_REG_X15)
CFI_OFFSET(_REG_X16)
CFI_OFFSET(_REG_X17)
CFI_OFFSET(_REG_X18)
CFI_OFFSET(_REG_X19)
CFI_OFFSET(_REG_X20)
CFI_OFFSET(_REG_X21)
CFI_OFFSET(_REG_X22)
CFI_OFFSET(_REG_X23)
CFI_OFFSET(_REG_X24)
CFI_OFFSET(_REG_X25)
CFI_OFFSET(_REG_X26)
CFI_OFFSET(_REG_X27)
CFI_OFFSET(_REG_X28)
CFI_OFFSET(_REG_X29)
CFI_OFFSET(_REG_X30) /* a.k.a. _REG_LR */
CFI_OFFSET(_REG_X31) /* a.k.a. _REG_SP */
.cfi_return_column DWARF_SIGRETURN_REG
CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC)
/*
* The unwind entry includes the one instruction prior to the trampoline
* because the unwinder will look up (return PC - 1) 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_NP(__sigtramp_siginfo_2)
mov x0, x28 /* set the arg */
SYSTRAP(setcontext) /* and call setcontext */
/* If that failed, exit with the error code. */
SYSTRAP(exit)
.cfi_endproc
END(__sigtramp_siginfo_2)
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