1/*-
  2 * SPDX-License-Identifier: BSD-3-Clause
  3 *
  4 * Copyright (c) 1999 Eivind Eklund <eivind@FreeBSD.org>
  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. Neither the name of the University nor the names of its contributors
 15 *    may be used to endorse or promote products derived from this software
 16 *    without specific prior written permission.
 17 *
 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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
 31#ifndef _SYS_KASSERT_H_
 32#define	_SYS_KASSERT_H_
 33
 34#include <sys/cdefs.h>
 35
 36#ifdef _KERNEL
 37extern const char *panicstr;	/* panic message */
 38extern bool panicked;
 39#define	KERNEL_PANICKED()	__predict_false(panicked)
 40
 41#ifdef	INVARIANTS		/* The option is always available */
 42#define	VNASSERT(exp, vp, msg) do {					\
 43	if (__predict_false(!(exp))) {					\
 44		vn_printf(vp, "VNASSERT failed: %s not true at %s:%d (%s)\n",\
 45		   #exp, __FILE__, __LINE__, __func__);	 		\
 46		kassert_panic msg;					\
 47	}								\
 48} while (0)
 49#define	MPASSERT(exp, mp, msg) do {					\
 50	if (__predict_false(!(exp))) {					\
 51		printf("MPASSERT mp %p failed: %s not true at %s:%d (%s)\n",\
 52		    (mp), #exp, __FILE__, __LINE__, __func__);		\
 53		kassert_panic msg;					\
 54	}								\
 55} while (0)
 56#define	VNPASS(exp, vp)	do {						\
 57	const char *_exp = #exp;					\
 58	VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)",	\
 59	    _exp, __FILE__, __LINE__, __func__));			\
 60} while (0)
 61#define	MPPASS(exp, mp)	do {						\
 62	const char *_exp = #exp;					\
 63	MPASSERT(exp, mp, ("condition %s not met at %s:%d (%s)",	\
 64	    _exp, __FILE__, __LINE__, __func__));			\
 65} while (0)
 66#define	__assert_unreachable() \
 67	panic("executing segment marked as unreachable at %s:%d (%s)\n", \
 68	    __FILE__, __LINE__, __func__)
 69#else	/* INVARIANTS */
 70#define	VNASSERT(exp, vp, msg) do { \
 71} while (0)
 72#define	MPASSERT(exp, mp, msg) do { \
 73} while (0)
 74#define	VNPASS(exp, vp) do { \
 75} while (0)
 76#define	MPPASS(exp, mp) do { \
 77} while (0)
 78#define	__assert_unreachable()	__unreachable()
 79#endif	/* INVARIANTS */
 80
 81#ifndef CTASSERT	/* Allow lint to override */
 82#define	CTASSERT(x)	_Static_assert(x, "compile-time assertion failed")
 83#endif
 84
 85/*
 86 * These functions need to be declared before the KASSERT macro is invoked in
 87 * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of
 88 * place compared to other function definitions in this header.  On the other
 89 * hand, this header is a bit disorganized anyway.
 90 */
 91void	panic(const char *, ...) __dead2 __printflike(1, 2);
 92void	vpanic(const char *, __va_list) __dead2 __printflike(1, 0);
 93#endif	/* _KERNEL */
 94
 95#if defined(_STANDALONE)
 96/*
 97 * Until we have more experience with KASSERTS that are called
 98 * from the boot loader, they are off. The bootloader does this
 99 * a little differently than the kernel (we just call printf atm).
100 * we avoid most of the common functions in the boot loader, so
101 * declare printf() here too.
102 */
103int	printf(const char *, ...) __printflike(1, 2);
104#  define kassert_panic printf
105#else /* !_STANDALONE */
106#  if defined(WITNESS) || defined(INVARIANT_SUPPORT)
107#    ifdef KASSERT_PANIC_OPTIONAL
108void	kassert_panic(const char *fmt, ...)  __printflike(1, 2);
109#    else
110#      define kassert_panic	panic
111#    endif /* KASSERT_PANIC_OPTIONAL */
112#  endif /* defined(WITNESS) || defined(INVARIANT_SUPPORT) */
113#endif /* _STANDALONE */
114
115/*
116 * Kernel assertion; see KASSERT(9) for details.
117 */
118#if (defined(_KERNEL) && defined(INVARIANTS)) || defined(_STANDALONE)
119#define	KASSERT(exp,msg) do {						\
120	if (__predict_false(!(exp)))					\
121		kassert_panic msg;					\
122} while (0)
123#else /* !(KERNEL && INVARIANTS) && !_STANDALONE */
124#define	KASSERT(exp,msg) do { \
125} while (0)
126#endif /* (_KERNEL && INVARIANTS) || _STANDALONE */
127
128#ifdef _KERNEL
129/*
130 * Macros for generating panic messages based on the exact condition text.
131 *
132 * NOTE: Use these with care, as the resulting message might omit key
133 * information required to understand the assertion failure. Consult the
134 * MPASS(9) man page for guidance.
135 */
136#define MPASS(ex)		MPASS4(ex, #ex, __FILE__, __LINE__)
137#define MPASS2(ex, what)	MPASS4(ex, what, __FILE__, __LINE__)
138#define MPASS3(ex, file, line)	MPASS4(ex, #ex, file, line)
139#define MPASS4(ex, what, file, line)					\
140	KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line))
141
142/*
143 * Assert that a pointer can be loaded from memory atomically.
144 *
145 * This assertion enforces stronger alignment than necessary.  For example,
146 * on some architectures, atomicity for unaligned loads will depend on
147 * whether or not the load spans multiple cache lines.
148 */
149#define	ASSERT_ATOMIC_LOAD_PTR(var, msg)				\
150	KASSERT(sizeof(var) == sizeof(void *) &&			\
151	    ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg)
152/*
153 * Assert that a thread is in critical(9) section.
154 */
155#define	CRITICAL_ASSERT(td)						\
156	KASSERT((td)->td_critnest >= 1, ("Not in critical section"))
157
158#endif /* _KERNEL */
159
160#endif	/* _SYS_KASSERT_H_ */