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__sigtramp2.S revision 1.3 
      1 /*	$NetBSD: __sigtramp2.S,v 1.3 2007/12/22 14:10:03 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  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by Michael Shalayeff.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
     25  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     26  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     27  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     29  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     31  * THE POSSIBILITY OF SUCH DAMAGE.
     32  *
     33  * Portitions of this file are derived from other sources, see
     34  * the copyrights and acknowledgements below.
     35  */
     36 /*
     37  * Copyright (c) 1990,1991,1992,1994 The University of Utah and
     38  * the Computer Systems Laboratory (CSL).  All rights reserved.
     39  *
     40  * THE UNIVERSITY OF UTAH AND CSL PROVIDE THIS SOFTWARE IN ITS "AS IS"
     41  * CONDITION, AND DISCLAIM ANY LIABILITY OF ANY KIND FOR ANY DAMAGES
     42  * WHATSOEVER RESULTING FROM ITS USE.
     43  *
     44  * CSL requests users of this software to return to csl-dist (at) cs.utah.edu any
     45  * improvements that they make and grant CSL redistribution rights.
     46  *
     47  *	Utah $Hdr: locore.s 1.62 94/12/15$
     48  */
     49 /*
     50  *  (c) Copyright 1988 HEWLETT-PACKARD COMPANY
     51  *
     52  *  To anyone who acknowledges that this file is provided "AS IS"
     53  *  without any express or implied warranty:
     54  *      permission to use, copy, modify, and distribute this file
     55  *  for any purpose is hereby granted without fee, provided that
     56  *  the above copyright notice and this notice appears in all
     57  *  copies, and that the name of Hewlett-Packard Company not be
     58  *  used in advertising or publicity pertaining to distribution
     59  *  of the software without specific, written prior permission.
     60  *  Hewlett-Packard Company makes no representations about the
     61  *  suitability of this software for any purpose.
     62  */
     63 
     64 #include "SYS.h"
     65 
     66 /*
     67  * The hppa signal trampoline is required to call the handler
     68  * possibily via a PLABEL.
     69  *
     70  * On entry, stack looks like:
     71  *
     72  *	sp->					[x]
     73  * r3,arg2->	ucontext structure
     74  *    arg1->	siginfo structure		[0]
     75  *
     76  * where
     77  *	x = HPPA_FRAME_ROUND(sizeof(sigframe_siginfo))
     78  *
     79  * and
     80  * 	struct sigframe_siginfo {
     81  *		siginfo_t sf_si;
     82  *		ucontext_t sf_uc;
     83  *	};
     84  */
     85 
     86 ENTRY_NOPROFILE(__sigtramp_siginfo_2, 0)
     87 	.call
     88 
     89 	/*
     90 	 * Our sendsig() places the address of the signal handler in %arg3.
     91 	 * It may actually be a PLABEL.
     92 	 */
     93 	bb,>=,n	%arg3, 30, L$sigcode_bounce	; branch if not a PLABEL
     94 	depi	0, 31, 2, %arg3			; zero L bit in PLABEL pointer
     95 	ldw	4(%arg3), %r19			; load shared library linkage
     96 	ldw	0(%arg3), %arg3			; load real catcher address
     97 
     98 L$sigcode_bounce:
     99 
    100 	/*
    101 	 * This blr puts the address of the following nop in rp.
    102 	 * It also schedules the nop for execution, which is why
    103 	 * that instruction has to be a nop, or, rather, not any
    104 	 * instruction only meant to execute once the signal handler
    105 	 * returns.
    106 	 */
    107 	blr	%r0, %rp
    108 
    109 	/*
    110 	 * This bv schedules the instruction pointed to by arg3
    111 	 * for execution.  So, arg3 is the address of the signal
    112 	 * handler.
    113 	 */
    114 	bv,n	%r0(%arg3)
    115 	nop
    116 
    117 	/*
    118 	 * The signal handler has returned.  Since r3 is on the list
    119 	 * of callee-saved registers, it's whatever the sendsig
    120 	 * code wanted it set to.  Since we copy it into arg0,
    121 	 * it looks like sendsig leaves r3 holding the desired
    122 	 * single argument to sys_setcontext, i.e., the ucontext_t *.
    123 	 */
    124 
    125 	/* Make a SYS_setcontext system call. */
    126 	copy	%r3, %arg0
    127 	ldil	L%SYSCALLGATE, %r1
    128 	.call
    129 	ble	4(%sr7, %r1)
    130 	ldi	SYS_setcontext, %t1
    131 
    132 	/* Make a SYS_exit system call. */
    133 	copy	%ret0, %arg0
    134 	ldil	L%SYSCALLGATE, %r1
    135 	.call
    136 	ble	4(%sr7, %r1)
    137 	ldi	SYS_exit, %t1
    138 EXIT(__sigtramp_siginfo_2)
    139