1/* $OpenBSD: witness.h,v 1.7 2025/07/05 09:24:37 jsg 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
72void witness_initialize(void);
73void witness_init(struct lock_object *, const struct lock_type *);
74int witness_defineorder(struct lock_object *, struct lock_object *);
75void witness_checkorder(struct lock_object *, int, struct lock_object *);
76void witness_lock(struct lock_object *, int);
77void witness_upgrade(struct lock_object *, int);
78void witness_downgrade(struct lock_object *, int);
79void witness_unlock(struct lock_object *, int);
80void witness_setrelative(struct lock_object *, struct lock_object *, int);
81int witness_warn(int, struct lock_object *, const char *, ...);
82void witness_assert(const struct lock_object *, int);
83void witness_display_spinlock(struct lock_object *, struct proc *,
84 int (*)(const char *, ...));
85void witness_norelease(struct lock_object *);
86void witness_releaseok(struct lock_object *);
87void witness_thread_exit(struct proc *);
88int witness_sysctl(int *, u_int, void *, size_t *, void *, size_t);
89int witness_sysctl_watch(void *, size_t *, void *, size_t);
90
91#ifdef WITNESS
92
93/* Flags for witness_warn(). */
94#define WARN_KERNELOK 0x01 /* Kernel lock is exempt from this check. */
95#define WARN_PANIC 0x02 /* Panic if check fails. */
96#define WARN_SLEEPOK 0x04 /* Sleepable locks are exempt from check. */
97
98#define WITNESS_INITIALIZE() \
99 witness_initialize()
100
101#define WITNESS_INIT(lock, type) \
102 witness_init((lock), (type))
103
104#define WITNESS_CHECKORDER(lock, flags, interlock) \
105 witness_checkorder((lock), (flags), (interlock))
106
107#define WITNESS_DEFINEORDER(lock1, lock2) \
108 witness_defineorder((struct lock_object *)(lock1), \
109 (struct lock_object *)(lock2))
110
111#define WITNESS_LOCK(lock, flags) \
112 witness_lock((lock), (flags))
113
114#define WITNESS_UPGRADE(lock, flags) \
115 witness_upgrade((lock), (flags))
116
117#define WITNESS_DOWNGRADE(lock, flags) \
118 witness_downgrade((lock), (flags))
119
120#define WITNESS_UNLOCK(lock, flags) \
121 witness_unlock((lock), (flags))
122
123/* Set permitted child lock for lock. */
124#define WITNESS_SETCHILD(lock, child) \
125 witness_setrelative((lock), (child), 0)
126
127/* Set permitted parent lock for lock. */
128#define WITNESS_SETPARENT(lock, parent) \
129 witness_setrelative((lock), (parent), 1)
130
131#define WITNESS_CHECK(flags, lock, fmt, ...) \
132 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
133
134#define WITNESS_WARN(flags, lock, fmt, ...) \
135 witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)
136
137#define WITNESS_NORELEASE(lock) \
138 witness_norelease(&(lock)->lock_object)
139
140#define WITNESS_RELEASEOK(lock) \
141 witness_releaseok(&(lock)->lock_object)
142
143#define WITNESS_THREAD_EXIT(p) \
144 witness_thread_exit((p))
145
146#else /* WITNESS */
147#define WITNESS_INITIALIZE() (void)0
148#define WITNESS_INIT(lock, type) (void)0
149#define WITNESS_DEFINEORDER(lock1, lock2) 0
150#define WITNESS_CHECKORDER(lock, flagsi, interlock) (void)0
151#define WITNESS_LOCK(lock, flags) (void)0
152#define WITNESS_UPGRADE(lock, flags) (void)0
153#define WITNESS_DOWNGRADE(lock, flags) (void)0
154#define WITNESS_UNLOCK(lock, flags) (void)0
155#define WITNESS_SETCHILD(lock, child) (void)0
156#define WITNESS_SETPARENT(lock, parent) (void)0
157#define WITNESS_CHECK(flags, lock, fmt, ...) 0
158#define WITNESS_WARN(flags, lock, fmt, ...) (void)0
159#define WITNESS_NORELEASE(lock) (void)0
160#define WITNESS_RELEASEOK(lock) (void)0
161#define WITNESS_THREAD_EXIT(p) (void)0
162#endif /* WITNESS */
163
164#endif /* _KERNEL */
165#endif /* _SYS_WITNESS_H_ */