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__sigtramp2.S revision 1.7 
      1 /*	$NetBSD: __sigtramp2.S,v 1.7 2022/06/26 14:37:13 skrll Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998-2001 Michael Shalayeff
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
     20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     22  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     26  * THE POSSIBILITY OF SUCH DAMAGE.
     27  *
     28  * Portitions of this file are derived from other sources, see
     29  * the copyrights and acknowledgements below.
     30  */
     31 /*
     32  * Copyright (c) 1990,1991,1992,1994 The University of Utah and
     33  * the Computer Systems Laboratory (CSL).  All rights reserved.
     34  *
     35  * THE UNIVERSITY OF UTAH AND CSL PROVIDE THIS SOFTWARE IN ITS "AS IS"
     36  * CONDITION, AND DISCLAIM ANY LIABILITY OF ANY KIND FOR ANY DAMAGES
     37  * WHATSOEVER RESULTING FROM ITS USE.
     38  *
     39  * CSL requests users of this software to return to csl-dist (at) cs.utah.edu any
     40  * improvements that they make and grant CSL redistribution rights.
     41  *
     42  *	Utah $Hdr: locore.s 1.62 94/12/15$
     43  */
     44 /*
     45  *  (c) Copyright 1988 HEWLETT-PACKARD COMPANY
     46  *
     47  *  To anyone who acknowledges that this file is provided "AS IS"
     48  *  without any express or implied warranty:
     49  *      permission to use, copy, modify, and distribute this file
     50  *  for any purpose is hereby granted without fee, provided that
     51  *  the above copyright notice and this notice appears in all
     52  *  copies, and that the name of Hewlett-Packard Company not be
     53  *  used in advertising or publicity pertaining to distribution
     54  *  of the software without specific, written prior permission.
     55  *  Hewlett-Packard Company makes no representations about the
     56  *  suitability of this software for any purpose.
     57  */
     58 
     59 #include "SYS.h"
     60 #include "assym.h"
     61 
     62 /*
     63  * The hppa signal trampoline is required to call the handler
     64  * possibily via a PLABEL.
     65  *
     66  * On entry, stack looks like:
     67  *
     68  *	sp->					[x]
     69  * r3,arg2->	ucontext structure
     70  *    arg1->	siginfo structure		[0]
     71  *
     72  * where
     73  *	x = HPPA_FRAME_ROUND(sizeof(sigframe_siginfo))
     74  *
     75  * and
     76  * 	struct sigframe_siginfo {
     77  *		siginfo_t sf_si;
     78  *		ucontext_t sf_uc;
     79  *	};
     80  *
     81  * The DWARF register numbers for the general purpose registers are the
     82  * same as the architected register numbers.  For HPPA, there is a DWARF
     83  * pseudo-register for signal handler return addresses.
     84  */
     85 
     86 #if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
     87 #define	DWARF_SIGRETURN_REG		__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
     88 #else
     89 #define	DWARF_SIGRETURN_REG		89	/* 61 on hppa64 */
     90 #endif
     91 
     92 #define	CFI_OFFSET_DWARF_REG(d, r)	.cfi_offset d, r * 4
     93 #define	CFI_OFFSET(r)			CFI_OFFSET_DWARF_REG(r, r)
     94 
     95 	.text
     96 	.cfi_startproc
     97 	.cfi_signal_frame
     98 	.cfi_def_cfa _REG_R30,  -SIZEOF_SIGTRAMP + SIZEOF_SIGINFO + _UC_GREGS
     99 	CFI_OFFSET(_REG_R1)
    100 	CFI_OFFSET(_REG_R2)
    101 	CFI_OFFSET(_REG_R3)
    102 	CFI_OFFSET(_REG_R4)
    103 	CFI_OFFSET(_REG_R5)
    104 	CFI_OFFSET(_REG_R6)
    105 	CFI_OFFSET(_REG_R7)
    106 	CFI_OFFSET(_REG_R8)
    107 	CFI_OFFSET(_REG_R9)
    108 	CFI_OFFSET(_REG_R10)
    109 	CFI_OFFSET(_REG_R11)
    110 	CFI_OFFSET(_REG_R12)
    111 	CFI_OFFSET(_REG_R13)
    112 	CFI_OFFSET(_REG_R14)
    113 	CFI_OFFSET(_REG_R15)
    114 	CFI_OFFSET(_REG_R16)
    115 	CFI_OFFSET(_REG_R17)
    116 	CFI_OFFSET(_REG_R18)
    117 	CFI_OFFSET(_REG_R19)
    118 	CFI_OFFSET(_REG_R20)
    119 	CFI_OFFSET(_REG_R21)
    120 	CFI_OFFSET(_REG_R22)
    121 	CFI_OFFSET(_REG_R23)
    122 	CFI_OFFSET(_REG_R24)
    123 	CFI_OFFSET(_REG_R25)
    124 	CFI_OFFSET(_REG_R26)
    125 	CFI_OFFSET(_REG_R27)
    126 	CFI_OFFSET(_REG_R28)
    127 	CFI_OFFSET(_REG_R29)
    128 	CFI_OFFSET(_REG_R30)
    129 	CFI_OFFSET(_REG_R31)
    130 	.cfi_return_column DWARF_SIGRETURN_REG
    131 	CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PCOQH)
    132 
    133 /*
    134  * The unwind entry includes one instruction slot prior to the trampoline
    135  * because the unwinder will look up to (return PC - 1 insn) while unwinding.
    136  * Normally this would be the jump / branch, but since there isn't one in
    137  * this case, we place an explicit nop there instead.
    138  */
    139 
    140 	nop
    141 
    142 ENTRY_NOPROFILE(__sigtramp_siginfo_2, 0)
    143 	.call
    144 
    145 	/*
    146 	 * Our sendsig() places the address of the signal handler in %arg3.
    147 	 * It may actually be a PLABEL.
    148 	 */
    149 	bb,>=,n	%arg3, 30, L$sigcode_bounce	; branch if not a PLABEL
    150 	depi	0, 31, 2, %arg3			; zero L bit in PLABEL pointer
    151 	ldw	4(%arg3), %r19			; load shared library linkage
    152 	ldw	0(%arg3), %arg3			; load real catcher address
    153 
    154 L$sigcode_bounce:
    155 
    156 	/*
    157 	 * This blr puts the address of the following nop in rp.
    158 	 * It also schedules the nop for execution, which is why
    159 	 * that instruction has to be a nop, or, rather, not any
    160 	 * instruction only meant to execute once the signal handler
    161 	 * returns.
    162 	 */
    163 	blr	%r0, %rp
    164 
    165 	/*
    166 	 * This bv schedules the instruction pointed to by arg3
    167 	 * for execution.  So, arg3 is the address of the signal
    168 	 * handler.
    169 	 */
    170 	bv,n	%r0(%arg3)
    171 	nop
    172 
    173 	/*
    174 	 * The signal handler has returned.  Since r3 is on the list
    175 	 * of callee-saved registers, it's whatever the sendsig
    176 	 * code wanted it set to.  Since we copy it into arg0,
    177 	 * it looks like sendsig leaves r3 holding the desired
    178 	 * single argument to sys_setcontext, i.e., the ucontext_t *.
    179 	 */
    180 
    181 	/* Make a SYS_setcontext system call. */
    182 	copy	%r3, %arg0
    183 	ldil	L%SYSCALLGATE, %r1
    184 	.call
    185 	ble	4(%sr2, %r1)
    186 	 ldi	SYS_setcontext, %t1
    187 
    188 	/* Make a SYS_exit system call. */
    189 	copy	%ret0, %arg0
    190 	ldil	L%SYSCALLGATE, %r1
    191 	.call
    192 	ble	4(%sr2, %r1)
    193 	 ldi	SYS_exit, %t1
    194 	.cfi_endproc
    195 EXIT(__sigtramp_siginfo_2)
    196