1 /*-
2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/9/lib/libkse/thread/thr_sigaltstack.c 174689 2007-12-16 23:29:57Z deischen $");
29
30 #include "namespace.h"
31 #include <errno.h>
32 #include <signal.h>
33 #include "un-namespace.h"
34 #include "thr_private.h"
35
36 int _sigaltstack(stack_t *_ss, stack_t *_oss);
37
38 __weak_reference(_sigaltstack, sigaltstack);
39
40 int
_sigaltstack(stack_t * _ss,stack_t * _oss)41 _sigaltstack(stack_t *_ss, stack_t *_oss)
42 {
43 struct pthread *curthread = _get_curthread();
44 stack_t ss, oss;
45 int oonstack, errsave, ret;
46 kse_critical_t crit;
47
48 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) {
49 crit = _kse_critical_enter();
50 ret = __sys_sigaltstack(_ss, _oss);
51 errsave = errno;
52 /* Get a copy */
53 if (ret == 0 && _ss != NULL)
54 curthread->sigstk = *_ss;
55 _kse_critical_leave(crit);
56 errno = errsave;
57 return (ret);
58 }
59
60 if (_ss)
61 ss = *_ss;
62 if (_oss)
63 oss = *_oss;
64
65 /* Should get and set stack in atomic way */
66 crit = _kse_critical_enter();
67 oonstack = _thr_sigonstack(&ss);
68 if (_oss != NULL) {
69 oss = curthread->sigstk;
70 oss.ss_flags = (curthread->sigstk.ss_flags & SS_DISABLE)
71 ? SS_DISABLE : ((oonstack) ? SS_ONSTACK : 0);
72 }
73
74 if (_ss != NULL) {
75 if (oonstack) {
76 _kse_critical_leave(crit);
77 errno = EPERM;
78 return (-1);
79 }
80 if ((ss.ss_flags & ~SS_DISABLE) != 0) {
81 _kse_critical_leave(crit);
82 errno = EINVAL;
83 return (-1);
84 }
85 if (!(ss.ss_flags & SS_DISABLE)) {
86 if (ss.ss_size < MINSIGSTKSZ) {
87 _kse_critical_leave(crit);
88 errno = ENOMEM;
89 return (-1);
90 }
91 curthread->sigstk = ss;
92 } else {
93 curthread->sigstk.ss_flags |= SS_DISABLE;
94 }
95 }
96 _kse_critical_leave(crit);
97 if (_oss != NULL)
98 *_oss = oss;
99 return (0);
100 }
101
102 int
_thr_sigonstack(void * sp)103 _thr_sigonstack(void *sp)
104 {
105 struct pthread *curthread = _get_curthread();
106
107 return ((curthread->sigstk.ss_flags & SS_DISABLE) == 0 ?
108 (((size_t)sp - (size_t)curthread->sigstk.ss_sp) < curthread->sigstk.ss_size)
109 : 0);
110 }
111
112