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 <pthread.h>
33 
34 #include "un-namespace.h"
35 #include "rtld_lock.h"
36 #include "thr_private.h"
37 
38 static int	_thr_rtld_clr_flag(int);
39 static void	*_thr_rtld_lock_create(void);
40 static void	_thr_rtld_lock_destroy(void *);
41 static void	_thr_rtld_lock_release(void *);
42 static void	_thr_rtld_rlock_acquire(void *);
43 static int	_thr_rtld_set_flag(int);
44 static void	_thr_rtld_wlock_acquire(void *);
45 
46 static void *
47 _thr_rtld_lock_create(void)
48 {
49 	pthread_rwlock_t prwlock;
50 	if (_pthread_rwlock_init(&prwlock, NULL))
51 		return (NULL);
52 	return (prwlock);
53 }
54 
55 static void
56 _thr_rtld_lock_destroy(void *lock)
57 {
58 	pthread_rwlock_t prwlock;
59 
60 	prwlock = (pthread_rwlock_t)lock;
61 	if (prwlock != NULL)
62 		_pthread_rwlock_destroy(&prwlock);
63 }
64 
65 static void
66 _thr_rtld_rlock_acquire(void *lock)
67 {
68 	pthread_rwlock_t prwlock;
69 
70 	prwlock = (pthread_rwlock_t)lock;
71 	_pthread_rwlock_rdlock(&prwlock);
72 }
73 
74 static void
75 _thr_rtld_wlock_acquire(void *lock)
76 {
77 	pthread_rwlock_t prwlock;
78 
79 	prwlock = (pthread_rwlock_t)lock;
80 	_pthread_rwlock_wrlock(&prwlock);
81 }
82 
83 static void
84 _thr_rtld_lock_release(void *lock)
85 {
86 	pthread_rwlock_t prwlock;
87 
88 	prwlock = (pthread_rwlock_t)lock;
89 	_pthread_rwlock_unlock(&prwlock);
90 }
91 
92 
93 static int
94 _thr_rtld_set_flag(int mask)
95 {
96 	struct pthread *curthread;
97 	int bits;
98 
99 	curthread = tls_get_curthread();
100 	if (curthread != NULL) {
101 		bits = curthread->rtld_bits;
102 		curthread->rtld_bits |= mask;
103 	} else {
104 		bits = 0;
105 		PANIC("No current thread in rtld call");
106 	}
107 
108 	return (bits);
109 }
110 
111 static int
112 _thr_rtld_clr_flag(int mask)
113 {
114 	struct pthread *curthread;
115 	int bits;
116 
117 	curthread = tls_get_curthread();
118 	if (curthread != NULL) {
119 		bits = curthread->rtld_bits;
120 		curthread->rtld_bits &= ~mask;
121 	} else {
122 		bits = 0;
123 		PANIC("No current thread in rtld call");
124 	}
125 	return (bits);
126 }
127 
128 void
129 _thr_rtld_init(void)
130 {
131 	struct RtldLockInfo li;
132 
133 	li.lock_create  = _thr_rtld_lock_create;
134 	li.lock_destroy = _thr_rtld_lock_destroy;
135 	li.rlock_acquire = _thr_rtld_rlock_acquire;
136 	li.wlock_acquire = _thr_rtld_wlock_acquire;
137 	li.lock_release  = _thr_rtld_lock_release;
138 	li.thread_set_flag = _thr_rtld_set_flag;
139 	li.thread_clr_flag = _thr_rtld_clr_flag;
140 	li.at_fork = NULL;
141 	_rtld_thread_init(&li);
142 }
143 
144 void
145 _thr_rtld_fini(void)
146 {
147 	_rtld_thread_init(NULL);
148 }
149