1/*	$NetBSD: longjmp.c,v 1.5 2024/02/20 00:09:31 uwe Exp $	*/
2
3/*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christian Limpach.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "namespace.h"
33#include <sys/types.h>
34#include <ucontext.h>
35#include <signal.h>
36#include <stdlib.h>
37#include <string.h>
38#include <stddef.h>
39
40#define __LIBC12_SOURCE__
41#include <setjmp.h>
42#include <compat/include/setjmp.h>
43
44#include "assym.h"
45#include "sparc_longjmp.h"
46
47/*
48 * check that offsets in the above structures match their usage in the
49 * setjmp() side of this setup.  a jmp_buf is the 12-word contents of
50 * the sigcontext structure, plus 2 more words for g4 and g7.
51 */
52__CTASSERT(_SIZEOF_SC + _JB_G4 == offsetof(struct __jmp_buf,regs.g4));
53__CTASSERT(_SIZEOF_SC + _JB_G7 == offsetof(struct __jmp_buf,regs.g7));
54__CTASSERT(sizeof(jmp_buf) >= sizeof(struct __jmp_buf));
55
56/*
57 * Use setcontext to reload the stack pointer, program counter <pc,npc>, and
58 * set the return value in %o0.  The %i and %l registers will be reloaded
59 * from the place to which %sp points.
60 */
61void
62__longjmp14(jmp_buf env, int val)
63{
64	struct __jmp_buf *context = (void *)env;
65	struct sigcontext *sc = &context->sc;
66	struct __jmp_buf_regs_t *r = &context->regs;
67	ucontext_t uc;
68
69	/* Ensure non-zero SP */
70	if (sc->sc_sp == 0)
71		goto err;
72
73	/* Initialise the context */
74	memset(&uc, 0, sizeof(uc));
75
76	/*
77	 * Set _UC_{SET,CLR}STACK according to SS_ONSTACK.
78	 *
79	 * Restore the signal mask with sigprocmask() instead of _UC_SIGMASK,
80	 * since libpthread may want to interpose on signal handling.
81	 */
82	uc.uc_flags = _UC_CPU | (sc->sc_onstack ? _UC_SETSTACK : _UC_CLRSTACK);
83
84	sigprocmask(SIG_SETMASK, &sc->sc_mask, NULL);
85
86	/* Extract PSR, PC, NPC and SP from jmp_buf */
87	uc.uc_mcontext.__gregs[_REG_PSR] = sc->sc_psr;
88	uc.uc_mcontext.__gregs[_REG_PC] = sc->sc_pc;
89	uc.uc_mcontext.__gregs[_REG_nPC] = sc->sc_pc+4;
90	uc.uc_mcontext.__gregs[_REG_O6] = sc->sc_sp;
91	uc.uc_mcontext.__gregs[_REG_G2] = sc->sc_g1;
92	uc.uc_mcontext.__gregs[_REG_G3] = sc->sc_npc;
93	uc.uc_mcontext.__gregs[_REG_G4] = r->g4;
94	uc.uc_mcontext.__gregs[_REG_G7] = r->g7;
95
96	/* Set the return value; make sure it's non-zero */
97	uc.uc_mcontext.__gregs[_REG_O0] = (val != 0 ? val : 1);
98
99	setcontext(&uc);
100
101err:
102	longjmperror();
103	abort();
104	/* NOTREACHED */
105}
106