1 /*
2  * Copyright (c) 2006, 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 unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD: src/lib/libpthread/thread/thr_rtld.c,v 1.5 2003/11/05 18:19:24 deischen Exp $
27  */
28 
29 #include "namespace.h"
30 #include <machine/tls.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <pthread.h>
34 
35 #include "un-namespace.h"
36 #include "rtld_lock.h"
37 #include "thr_private.h"
38 
39 static int	_thr_rtld_clr_flag(int);
40 static void	*_thr_rtld_lock_create(void);
41 static void	_thr_rtld_lock_destroy(void *);
42 static void	_thr_rtld_lock_release(void *);
43 static void	_thr_rtld_rlock_acquire(void *);
44 static int	_thr_rtld_set_flag(int);
45 static void	_thr_rtld_wlock_acquire(void *);
46 
47 static void *
48 _thr_rtld_lock_create(void)
49 {
50 	pthread_rwlock_t prwlock;
51 	if (_pthread_rwlock_init(&prwlock, NULL))
52 		return (NULL);
53 	return (prwlock);
54 }
55 
56 static void
57 _thr_rtld_lock_destroy(void *lock)
58 {
59 	pthread_rwlock_t prwlock;
60 
61 	prwlock = (pthread_rwlock_t)lock;
62 	if (prwlock != NULL)
63 		_pthread_rwlock_destroy(&prwlock);
64 }
65 
66 static void
67 _thr_rtld_rlock_acquire(void *lock)
68 {
69 	pthread_rwlock_t prwlock;
70 
71 	prwlock = (pthread_rwlock_t)lock;
72 	_pthread_rwlock_rdlock(&prwlock);
73 }
74 
75 static void
76 _thr_rtld_wlock_acquire(void *lock)
77 {
78 	pthread_rwlock_t prwlock;
79 
80 	prwlock = (pthread_rwlock_t)lock;
81 	_pthread_rwlock_wrlock(&prwlock);
82 }
83 
84 static void
85 _thr_rtld_lock_release(void *lock)
86 {
87 	pthread_rwlock_t prwlock;
88 
89 	prwlock = (pthread_rwlock_t)lock;
90 	_pthread_rwlock_unlock(&prwlock);
91 }
92 
93 
94 static int
95 _thr_rtld_set_flag(int mask)
96 {
97 	struct pthread *curthread;
98 	int bits;
99 
100 	curthread = tls_get_curthread();
101 	if (curthread != NULL) {
102 		bits = curthread->rtld_bits;
103 		curthread->rtld_bits |= mask;
104 	} else {
105 		bits = 0;
106 		PANIC("No current thread in rtld call");
107 	}
108 
109 	return (bits);
110 }
111 
112 static int
113 _thr_rtld_clr_flag(int mask)
114 {
115 	struct pthread *curthread;
116 	int bits;
117 
118 	curthread = tls_get_curthread();
119 	if (curthread != NULL) {
120 		bits = curthread->rtld_bits;
121 		curthread->rtld_bits &= ~mask;
122 	} else {
123 		bits = 0;
124 		PANIC("No current thread in rtld call");
125 	}
126 	return (bits);
127 }
128 
129 void
130 _thr_rtld_init(void)
131 {
132 	struct RtldLockInfo li;
133 	static int once = 0;
134 
135 	memset(&li, 0, sizeof(li));
136 	li.lock_create  = _thr_rtld_lock_create;
137 	li.lock_destroy = _thr_rtld_lock_destroy;
138 	li.rlock_acquire = _thr_rtld_rlock_acquire;
139 	li.wlock_acquire = _thr_rtld_wlock_acquire;
140 	li.lock_release  = _thr_rtld_lock_release;
141 	li.thread_set_flag = _thr_rtld_set_flag;
142 	li.thread_clr_flag = _thr_rtld_clr_flag;
143 	li.at_fork = NULL;
144 	_rtld_thread_init(&li);
145 	if (once == 0) {
146 		once = 1;
147 		_thr_atfork_kern(_rtld_thread_prefork,
148 				 _rtld_thread_postfork,
149 				 _rtld_thread_childfork);
150 	}
151 }
152 
153 void
154 _thr_rtld_fini(void)
155 {
156 	_rtld_thread_init(NULL);
157 }
158