__sigtramp2.S revision 1.2 
1/*	$NetBSD: __sigtramp2.S,v 1.2 2005/06/05 19:01:04 chs 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@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
66ENTRY_NOPROFILE(__sigtramp_siginfo_2, 0)
67	.call
68
69	/*
70	 * Our sendsig() places the address of the signal handler in %arg3.
71	 * It may actually be a PLABEL.
72	 */
73	bb,>=,n	%arg3, 30, L$sigcode_bounce	; branch if not a PLABEL
74	depi	0, 31, 2, %arg3			; zero L bit in PLABEL pointer
75	ldw	4(%arg3), %r19			; load shared library linkage
76	ldw	0(%arg3), %arg3			; load real catcher address
77
78L$sigcode_bounce:
79
80	/*
81	 * This blr puts the address of the following nop in rp.
82	 * It also schedules the nop for execution, which is why
83	 * that instruction has to be a nop, or, rather, not any
84	 * instruction only meant to execute once the signal handler
85	 * returns.
86	 */
87	blr	%r0, %rp
88
89	/*
90	 * This bv schedules the instruction pointed to by arg3
91	 * for execution.  So, arg3 is the address of the signal
92	 * handler.
93	 */
94	bv,n	%r0(%arg3)
95	nop
96
97	/*
98	 * The signal handler has returned.  Since r3 is on the list
99	 * of callee-saved registers, it's whatever the sendsig
100	 * code wanted it set to.  Since we copy it into arg0,
101	 * it looks like sendsig leaves r3 holding the desired
102	 * single argument to sys_setcontext, i.e., the ucontext_t *.
103	 */
104
105	/* Make a SYS_setcontext system call. */
106	copy	%r3, %arg0
107	ldil	L%SYSCALLGATE, %r1
108	.call
109	ble	4(%sr7, %r1)
110	ldi	SYS_setcontext, %t1
111
112	/* Make a SYS_exit system call. */
113	copy	%ret0, %arg0
114	ldil	L%SYSCALLGATE, %r1
115	.call
116	ble	4(%sr7, %r1)
117	ldi	SYS_exit, %t1
118EXIT(__sigtramp_siginfo_2)
119