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 */
61 void
__longjmp14(jmp_buf env,int val)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
101 err:
102 longjmperror();
103 abort();
104 /* NOTREACHED */
105 }
106