xref: /openbsd/sys/sys/witness.h (revision 8c00de5e)
1 /*	$OpenBSD: witness.h,v 1.5 2019/04/23 13:35:12 visa Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following 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  * 3. Berkeley Software Design Inc's name may not be used to endorse or
15  *    promote products derived from this software without specific prior
16  *    written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	from BSDI Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp
31  * $FreeBSD: head/sys/sys/lock.h 313908 2017-02-18 01:52:10Z mjg $
32  */
33 
34 #ifndef _SYS_WITNESS_H_
35 #define _SYS_WITNESS_H_
36 
37 #include <sys/_lock.h>
38 
39 /*
40  * Lock classes are statically assigned an index into the global lock_classes
41  * array.  Debugging code looks up the lock class for a given lock object
42  * by indexing the array.
43  */
44 #define	LO_CLASSINDEX(lock) \
45 	((((lock)->lo_flags) & LO_CLASSMASK) >> LO_CLASSSHIFT)
46 #define	LOCK_CLASS(lock) \
47 	(lock_classes[LO_CLASSINDEX((lock))])
48 #define	LOCK_CLASS_MAX \
49 	(LO_CLASSMASK >> LO_CLASSSHIFT)
50 
51 /*
52  * Option flags passed to lock operations that witness also needs to know
53  * about or that are generic across all locks.
54  */
55 #define	LOP_NEWORDER	0x00000001	/* Define a new lock order. */
56 #define	LOP_QUIET	0x00000002	/* Don't log locking operations. */
57 #define	LOP_TRYLOCK	0x00000004	/* Don't check lock order. */
58 #define	LOP_EXCLUSIVE	0x00000008	/* Exclusive lock. */
59 #define	LOP_DUPOK	0x00000010	/* Don't check for duplicate acquires */
60 
61 /* Flags passed to witness_assert. */
62 #define	LA_MASKASSERT	0x000000ff	/* Mask for witness defined asserts. */
63 #define	LA_UNLOCKED	0x00000000	/* Lock is unlocked. */
64 #define	LA_LOCKED	0x00000001	/* Lock is at least share locked. */
65 #define	LA_SLOCKED	0x00000002	/* Lock is exactly share locked. */
66 #define	LA_XLOCKED	0x00000004	/* Lock is exclusively locked. */
67 #define	LA_RECURSED	0x00000008	/* Lock is recursed. */
68 #define	LA_NOTRECURSED	0x00000010	/* Lock is not recursed. */
69 
70 #ifdef _KERNEL
71 
72 void	witness_initialize(void);
73 void	witness_init(struct lock_object *, const struct lock_type *);
74 int	witness_defineorder(struct lock_object *, struct lock_object *);
75 void	witness_checkorder(struct lock_object *, int, struct lock_object *);
76 void	witness_lock(struct lock_object *, int);
77 void	witness_upgrade(struct lock_object *, int);
78 void	witness_downgrade(struct lock_object *, int);
79 void	witness_unlock(struct lock_object *, int);
80 int	witness_warn(int, struct lock_object *, const char *, ...);
81 void	witness_assert(const struct lock_object *, int);
82 void	witness_display_spinlock(struct lock_object *, struct proc *,
83 	    int (*)(const char *, ...));
84 int	witness_line(struct lock_object *);
85 void	witness_norelease(struct lock_object *);
86 void	witness_releaseok(struct lock_object *);
87 const char *witness_file(struct lock_object *);
88 void	witness_thread_exit(struct proc *);
89 int	witness_sysctl(int *, u_int, void *, size_t *, void *, size_t);
90 int	witness_sysctl_watch(void *, size_t *, void *, size_t);
91 
92 #ifdef	WITNESS
93 
94 /* Flags for witness_warn(). */
95 #define	WARN_KERNELOK	0x01	/* Kernel lock is exempt from this check. */
96 #define	WARN_PANIC	0x02	/* Panic if check fails. */
97 #define	WARN_SLEEPOK	0x04	/* Sleepable locks are exempt from check. */
98 
99 #define	WITNESS_INITIALIZE()						\
100 	witness_initialize()
101 
102 #define	WITNESS_INIT(lock, type)					\
103 	witness_init((lock), (type))
104 
105 #define	WITNESS_CHECKORDER(lock, flags, interlock)			\
106 	witness_checkorder((lock), (flags), (interlock))
107 
108 #define	WITNESS_DEFINEORDER(lock1, lock2)				\
109 	witness_defineorder((struct lock_object *)(lock1),		\
110 	    (struct lock_object *)(lock2))
111 
112 #define	WITNESS_LOCK(lock, flags)					\
113 	witness_lock((lock), (flags))
114 
115 #define	WITNESS_UPGRADE(lock, flags)					\
116 	witness_upgrade((lock), (flags))
117 
118 #define	WITNESS_DOWNGRADE(lock, flags)					\
119 	witness_downgrade((lock), (flags))
120 
121 #define	WITNESS_UNLOCK(lock, flags)					\
122 	witness_unlock((lock), (flags))
123 
124 #define	WITNESS_CHECK(flags, lock, fmt, ...)				\
125 	witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
126 
127 #define	WITNESS_WARN(flags, lock, fmt, ...)				\
128 	witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
129 
130 #define	WITNESS_NORELEASE(lock)						\
131 	witness_norelease(&(lock)->lock_object)
132 
133 #define	WITNESS_RELEASEOK(lock)						\
134 	witness_releaseok(&(lock)->lock_object)
135 
136 #define	WITNESS_THREAD_EXIT(p)						\
137 	witness_thread_exit((p))
138 
139 #else	/* WITNESS */
140 #define	WITNESS_INITIALIZE()					(void)0
141 #define	WITNESS_INIT(lock, type)				(void)0
142 #define	WITNESS_DEFINEORDER(lock1, lock2)	0
143 #define	WITNESS_CHECKORDER(lock, flagsi, interlock)		(void)0
144 #define	WITNESS_LOCK(lock, flags)				(void)0
145 #define	WITNESS_UPGRADE(lock, flags)				(void)0
146 #define	WITNESS_DOWNGRADE(lock, flags)				(void)0
147 #define	WITNESS_UNLOCK(lock, flags)				(void)0
148 #define	WITNESS_CHECK(flags, lock, fmt, ...)	0
149 #define	WITNESS_WARN(flags, lock, fmt, ...)			(void)0
150 #define	WITNESS_NORELEASE(lock)					(void)0
151 #define	WITNESS_RELEASEOK(lock)					(void)0
152 #define	WITNESS_THREAD_EXIT(p)					(void)0
153 #endif	/* WITNESS */
154 
155 #endif	/* _KERNEL */
156 #endif	/* _SYS_WITNESS_H_ */
157