1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1999 Eivind Eklund <[email protected]> 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 37 extern const char *panicstr; /* panic message */ 38 extern 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 VNPASS(exp, vp) do { \ 50 const char *_exp = #exp; \ 51 VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)", \ 52 _exp, __FILE__, __LINE__, __func__)); \ 53 } while (0) 54 #define __assert_unreachable() \ 55 panic("executing segment marked as unreachable at %s:%d (%s)\n", \ 56 __FILE__, __LINE__, __func__) 57 #else /* INVARIANTS */ 58 #define VNASSERT(exp, vp, msg) do { \ 59 } while (0) 60 #define VNPASS(exp, vp) do { \ 61 } while (0) 62 #define __assert_unreachable() __unreachable() 63 #endif /* INVARIANTS */ 64 65 #ifndef CTASSERT /* Allow lint to override */ 66 #define CTASSERT(x) _Static_assert(x, "compile-time assertion failed") 67 #endif 68 69 /* 70 * These functions need to be declared before the KASSERT macro is invoked in 71 * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of 72 * place compared to other function definitions in this header. On the other 73 * hand, this header is a bit disorganized anyway. 74 */ 75 void panic(const char *, ...) __dead2 __printflike(1, 2); 76 void vpanic(const char *, __va_list) __dead2 __printflike(1, 0); 77 #endif /* _KERNEL */ 78 79 #if defined(_STANDALONE) 80 /* 81 * Until we have more experience with KASSERTS that are called 82 * from the boot loader, they are off. The bootloader does this 83 * a little differently than the kernel (we just call printf atm). 84 * we avoid most of the common functions in the boot loader, so 85 * declare printf() here too. 86 */ 87 int printf(const char *, ...) __printflike(1, 2); 88 # define kassert_panic printf 89 #else /* !_STANDALONE */ 90 # if defined(WITNESS) || defined(INVARIANT_SUPPORT) 91 # ifdef KASSERT_PANIC_OPTIONAL 92 void kassert_panic(const char *fmt, ...) __printflike(1, 2); 93 # else 94 # define kassert_panic panic 95 # endif /* KASSERT_PANIC_OPTIONAL */ 96 # endif /* defined(WITNESS) || defined(INVARIANT_SUPPORT) */ 97 #endif /* _STANDALONE */ 98 99 #if (defined(_KERNEL) && defined(INVARIANTS)) || defined(_STANDALONE) 100 #define KASSERT(exp,msg) do { \ 101 if (__predict_false(!(exp))) \ 102 kassert_panic msg; \ 103 } while (0) 104 #else /* !(KERNEL && INVARIANTS) && !_STANDALONE */ 105 #define KASSERT(exp,msg) do { \ 106 } while (0) 107 #endif /* (_KERNEL && INVARIANTS) || _STANDALONE */ 108 109 #ifdef _KERNEL 110 /* 111 * Helpful macros for quickly coming up with assertions with informative 112 * panic messages. 113 */ 114 #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__) 115 #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__) 116 #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line) 117 #define MPASS4(ex, what, file, line) \ 118 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line)) 119 120 /* 121 * Assert that a pointer can be loaded from memory atomically. 122 * 123 * This assertion enforces stronger alignment than necessary. For example, 124 * on some architectures, atomicity for unaligned loads will depend on 125 * whether or not the load spans multiple cache lines. 126 */ 127 #define ASSERT_ATOMIC_LOAD_PTR(var, msg) \ 128 KASSERT(sizeof(var) == sizeof(void *) && \ 129 ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg) 130 /* 131 * Assert that a thread is in critical(9) section. 132 */ 133 #define CRITICAL_ASSERT(td) \ 134 KASSERT((td)->td_critnest >= 1, ("Not in critical section")) 135 136 /* 137 * If we have already panic'd and this is the thread that called 138 * panic(), then don't block on any mutexes but silently succeed. 139 * Otherwise, the kernel will deadlock since the scheduler isn't 140 * going to run the thread that holds any lock we need. 141 */ 142 #define SCHEDULER_STOPPED_TD(td) ({ \ 143 MPASS((td) == curthread); \ 144 __predict_false((td)->td_stopsched); \ 145 }) 146 #define SCHEDULER_STOPPED() SCHEDULER_STOPPED_TD(curthread) 147 #endif /* _KERNEL */ 148 149 #endif /* _SYS_KASSERT_H_ */ 150