1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004 Olivier Houchard
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 AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/param.h>
30#include <sys/signal.h>
31#include <sys/ucontext.h>
32
33#include <machine/frame.h>
34#include <machine/sigframe.h>
35
36#include <errno.h>
37#include <stdarg.h>
38#include <stdlib.h>
39#include <unistd.h>
40#include <strings.h>
41#include <signal.h>
42
43__weak_reference(__signalcontext, signalcontext);
44
45extern void _ctx_start(void);
46
47int
48__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
49{
50	struct sigframe *sfp;
51	__greg_t *gr = ucp->uc_mcontext.__gregs;
52	unsigned int *sp;
53
54	sp = (unsigned int *)gr[_REG_SP];
55
56	sfp = (struct sigframe *)sp - 1;
57
58	bzero(sfp, sizeof(*sfp));
59	bcopy(ucp, &sfp->sf_uc, sizeof(*ucp));
60	sfp->sf_si.si_signo = sig;
61
62	gr[_REG_SP] = (__greg_t)sfp;
63	/* Wipe out frame pointer. */
64	gr[_REG_FP] = 0;
65	/* Arrange for return via the trampoline code. */
66	gr[_REG_PC] = (__greg_t)_ctx_start;
67	gr[_REG_R4] = (__greg_t)func;
68	gr[_REG_R5] = (__greg_t)ucp;
69	gr[_REG_R0] = (__greg_t)sig;
70	gr[_REG_R1] = (__greg_t)&sfp->sf_si;
71	gr[_REG_R2] = (__greg_t)&sfp->sf_uc;
72
73	ucp->uc_link = &sfp->sf_uc;
74	sigdelset(&ucp->uc_sigmask, sig);
75
76	return (0);
77}
78