xref: /freebsd/libexec/rtld-elf/rtld_lock.h (revision 95be9288f01f30a50440ea56d11468a2c6e18fed)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright 2003 Alexander Kabaev.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #ifndef _RTLD_LOCK_H_
31 #define	_RTLD_LOCK_H_
32 
33 #define	RTLI_VERSION	0x01
34 #define	MAX_RTLD_LOCKS	8
35 
36 struct RtldLockInfo
37 {
38 	unsigned int rtli_version;
39 	void *(*lock_create)(void);
40 	void  (*lock_destroy)(void *);
41 	void  (*rlock_acquire)(void *);
42 	void  (*wlock_acquire)(void *);
43 	void  (*lock_release)(void *);
44 	int   (*thread_set_flag)(int);
45 	int   (*thread_clr_flag)(int);
46 	void  (*at_fork)(void);
47 };
48 
49 #if defined(IN_RTLD) || defined(PTHREAD_KERNEL)
50 
51 void _rtld_thread_init(struct RtldLockInfo *) __exported;
52 void _rtld_atfork_pre(int *) __exported;
53 void _rtld_atfork_post(int *) __exported;
54 
55 #endif /* IN_RTLD || PTHREAD_KERNEL */
56 
57 #ifdef IN_RTLD
58 
59 struct rtld_lock;
60 typedef struct rtld_lock *rtld_lock_t;
61 
62 extern rtld_lock_t	rtld_bind_lock;
63 extern rtld_lock_t	rtld_libc_lock;
64 extern rtld_lock_t	rtld_phdr_lock;
65 
66 #define	RTLD_LOCK_UNLOCKED	0
67 #define	RTLD_LOCK_RLOCKED	1
68 #define	RTLD_LOCK_WLOCKED	2
69 
70 struct Struct_RtldLockState;
71 typedef struct Struct_RtldLockState RtldLockState;
72 
73 void	rlock_acquire(rtld_lock_t, RtldLockState *);
74 void 	wlock_acquire(rtld_lock_t, RtldLockState *);
75 void	lock_release(rtld_lock_t, RtldLockState *);
76 void	lock_upgrade(rtld_lock_t, RtldLockState *);
77 void	lock_restart_for_upgrade(RtldLockState *);
78 
79 #endif	/* IN_RTLD */
80 
81 #endif
82