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/_types.h> 35 #include <sys/cdefs.h> 36 37 #ifdef _KERNEL 38 extern const char *panicstr; /* panic message */ 39 #define KERNEL_PANICKED() __predict_false(panicstr != NULL) 40 41 /* 42 * Trap accesses going through a pointer. 43 * 44 * Sample usage: you have a struct with numerous fields and by API contract 45 * only some of them get populated, even if the implementation temporary writes 46 * to them. You can use DEBUG_POISON_POINTER so that the consumer which should 47 * no be looking at the field gets caught. 48 * 49 * DEBUG_POISON_POINTER(obj->ptr); 50 * .... 51 * if (obj->ptr->field) // traps 52 */ 53 #ifdef INVARIANTS 54 55 extern void *poisoned_buf; 56 #define DEBUG_POISON_POINTER_VALUE poisoned_buf 57 58 #define DEBUG_POISON_POINTER(x) ({ \ 59 x = (DEBUG_POISON_POINTER_VALUE); \ 60 }) 61 62 #else 63 #define DEBUG_POISON_POINTER(x) 64 #endif 65 66 #ifdef INVARIANTS /* The option is always available */ 67 #define VNASSERT(exp, vp, msg) do { \ 68 if (__predict_false(!(exp))) { \ 69 vn_printf(vp, "VNASSERT failed: %s not true at %s:%d (%s)\n",\ 70 #exp, __FILE__, __LINE__, __func__); \ 71 kassert_panic msg; \ 72 } \ 73 } while (0) 74 #define MPASSERT(exp, mp, msg) do { \ 75 if (__predict_false(!(exp))) { \ 76 printf("MPASSERT mp %p failed: %s not true at %s:%d (%s)\n",\ 77 (mp), #exp, __FILE__, __LINE__, __func__); \ 78 kassert_panic msg; \ 79 } \ 80 } while (0) 81 #define VNPASS(exp, vp) do { \ 82 const char *_exp = #exp; \ 83 VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)", \ 84 _exp, __FILE__, __LINE__, __func__)); \ 85 } while (0) 86 #define MPPASS(exp, mp) do { \ 87 const char *_exp = #exp; \ 88 MPASSERT(exp, mp, ("condition %s not met at %s:%d (%s)", \ 89 _exp, __FILE__, __LINE__, __func__)); \ 90 } while (0) 91 #define __assert_unreachable() \ 92 panic("executing segment marked as unreachable at %s:%d (%s)\n", \ 93 __FILE__, __LINE__, __func__) 94 #else /* INVARIANTS */ 95 #define VNASSERT(exp, vp, msg) do { \ 96 } while (0) 97 #define MPASSERT(exp, mp, msg) do { \ 98 } while (0) 99 #define VNPASS(exp, vp) do { \ 100 } while (0) 101 #define MPPASS(exp, mp) do { \ 102 } while (0) 103 #define __assert_unreachable() __unreachable() 104 #endif /* INVARIANTS */ 105 106 #ifndef CTASSERT /* Allow lint to override */ 107 #define CTASSERT(x) _Static_assert(x, "compile-time assertion failed") 108 #endif 109 110 /* 111 * These functions need to be declared before the KASSERT macro is invoked in 112 * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of 113 * place compared to other function definitions in this header. On the other 114 * hand, this header is a bit disorganized anyway. 115 */ 116 void panic(const char *, ...) __dead2 __printflike(1, 2); 117 void vpanic(const char *, __va_list) __dead2 __printflike(1, 0); 118 #endif /* _KERNEL */ 119 120 #if defined(_STANDALONE) 121 /* 122 * Until we have more experience with KASSERTS that are called 123 * from the boot loader, they are off. The bootloader does this 124 * a little differently than the kernel (we just call printf atm). 125 * we avoid most of the common functions in the boot loader, so 126 * declare printf() here too. 127 */ 128 int printf(const char *, ...) __printflike(1, 2); 129 # define kassert_panic printf 130 #else /* !_STANDALONE */ 131 # if defined(WITNESS) || defined(INVARIANT_SUPPORT) 132 # ifdef KASSERT_PANIC_OPTIONAL 133 void kassert_panic(const char *fmt, ...) __printflike(1, 2); 134 # else 135 # define kassert_panic panic 136 # endif /* KASSERT_PANIC_OPTIONAL */ 137 # endif /* defined(WITNESS) || defined(INVARIANT_SUPPORT) */ 138 #endif /* _STANDALONE */ 139 140 /* 141 * Kernel assertion; see KASSERT(9) for details. 142 */ 143 #if (defined(_KERNEL) && defined(INVARIANTS)) || defined(_STANDALONE) 144 #define KASSERT(exp,msg) do { \ 145 if (__predict_false(!(exp))) \ 146 kassert_panic msg; \ 147 } while (0) 148 #else /* !(KERNEL && INVARIANTS) && !_STANDALONE */ 149 #define KASSERT(exp,msg) do { \ 150 } while (0) 151 #endif /* (_KERNEL && INVARIANTS) || _STANDALONE */ 152 153 #ifdef _KERNEL 154 /* 155 * Macros for generating panic messages based on the exact condition text. 156 * 157 * NOTE: Use these with care, as the resulting message might omit key 158 * information required to understand the assertion failure. Consult the 159 * MPASS(9) man page for guidance. 160 */ 161 #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__) 162 #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__) 163 #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line) 164 #define MPASS4(ex, what, file, line) \ 165 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line)) 166 167 /* 168 * Assert that a pointer can be loaded from memory atomically. 169 * 170 * This assertion enforces stronger alignment than necessary. For example, 171 * on some architectures, atomicity for unaligned loads will depend on 172 * whether or not the load spans multiple cache lines. 173 */ 174 #define ASSERT_ATOMIC_LOAD_PTR(var, msg) \ 175 KASSERT(sizeof(var) == sizeof(void *) && \ 176 ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg) 177 /* 178 * Assert that a thread is in critical(9) section. 179 */ 180 #define CRITICAL_ASSERT(td) \ 181 KASSERT((td)->td_critnest >= 1, ("Not in critical section")) 182 183 #endif /* _KERNEL */ 184 185 #endif /* _SYS_KASSERT_H_ */ 186