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 37 extern const char *panicstr; /* panic message */ 38 #define KERNEL_PANICKED() __predict_false(panicstr != NULL) 39 40 /* 41 * Trap accesses going through a pointer. Moreover if kasan is available trap 42 * reading the pointer itself. 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 != NULL) // traps with kasan, does not trap otherwise 52 * .... 53 * if (obj->ptr->field) // traps with and without kasan 54 */ 55 #ifdef INVARIANTS 56 57 #include <sys/asan.h> 58 59 extern caddr_t poisoned_buf; 60 #define DEBUG_POISON_POINTER_VALUE poisoned_buf 61 62 #define DEBUG_POISON_POINTER(x) ({ \ 63 x = (void *)(DEBUG_POISON_POINTER_VALUE); \ 64 kasan_mark(&x, 0, sizeof(x), KASAN_GENERIC_REDZONE); \ 65 }) 66 67 #else 68 #define DEBUG_POISON_POINTER(x) 69 #endif 70 71 #ifdef INVARIANTS /* The option is always available */ 72 #define VNASSERT(exp, vp, msg) do { \ 73 if (__predict_false(!(exp))) { \ 74 vn_printf(vp, "VNASSERT failed: %s not true at %s:%d (%s)\n",\ 75 #exp, __FILE__, __LINE__, __func__); \ 76 kassert_panic msg; \ 77 } \ 78 } while (0) 79 #define MPASSERT(exp, mp, msg) do { \ 80 if (__predict_false(!(exp))) { \ 81 printf("MPASSERT mp %p failed: %s not true at %s:%d (%s)\n",\ 82 (mp), #exp, __FILE__, __LINE__, __func__); \ 83 kassert_panic msg; \ 84 } \ 85 } while (0) 86 #define VNPASS(exp, vp) do { \ 87 const char *_exp = #exp; \ 88 VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)", \ 89 _exp, __FILE__, __LINE__, __func__)); \ 90 } while (0) 91 #define MPPASS(exp, mp) do { \ 92 const char *_exp = #exp; \ 93 MPASSERT(exp, mp, ("condition %s not met at %s:%d (%s)", \ 94 _exp, __FILE__, __LINE__, __func__)); \ 95 } while (0) 96 #define __assert_unreachable() \ 97 panic("executing segment marked as unreachable at %s:%d (%s)\n", \ 98 __FILE__, __LINE__, __func__) 99 #else /* INVARIANTS */ 100 #define VNASSERT(exp, vp, msg) do { \ 101 } while (0) 102 #define MPASSERT(exp, mp, msg) do { \ 103 } while (0) 104 #define VNPASS(exp, vp) do { \ 105 } while (0) 106 #define MPPASS(exp, mp) do { \ 107 } while (0) 108 #define __assert_unreachable() __unreachable() 109 #endif /* INVARIANTS */ 110 111 #ifndef CTASSERT /* Allow lint to override */ 112 #define CTASSERT(x) _Static_assert(x, "compile-time assertion failed") 113 #endif 114 115 /* 116 * These functions need to be declared before the KASSERT macro is invoked in 117 * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of 118 * place compared to other function definitions in this header. On the other 119 * hand, this header is a bit disorganized anyway. 120 */ 121 void panic(const char *, ...) __dead2 __printflike(1, 2); 122 void vpanic(const char *, __va_list) __dead2 __printflike(1, 0); 123 #endif /* _KERNEL */ 124 125 #if defined(_STANDALONE) 126 /* 127 * Until we have more experience with KASSERTS that are called 128 * from the boot loader, they are off. The bootloader does this 129 * a little differently than the kernel (we just call printf atm). 130 * we avoid most of the common functions in the boot loader, so 131 * declare printf() here too. 132 */ 133 int printf(const char *, ...) __printflike(1, 2); 134 # define kassert_panic printf 135 #else /* !_STANDALONE */ 136 # if defined(WITNESS) || defined(INVARIANT_SUPPORT) 137 # ifdef KASSERT_PANIC_OPTIONAL 138 void kassert_panic(const char *fmt, ...) __printflike(1, 2); 139 # else 140 # define kassert_panic panic 141 # endif /* KASSERT_PANIC_OPTIONAL */ 142 # endif /* defined(WITNESS) || defined(INVARIANT_SUPPORT) */ 143 #endif /* _STANDALONE */ 144 145 /* 146 * Kernel assertion; see KASSERT(9) for details. 147 */ 148 #if (defined(_KERNEL) && defined(INVARIANTS)) || defined(_STANDALONE) 149 #define KASSERT(exp,msg) do { \ 150 if (__predict_false(!(exp))) \ 151 kassert_panic msg; \ 152 } while (0) 153 #else /* !(KERNEL && INVARIANTS) && !_STANDALONE */ 154 #define KASSERT(exp,msg) do { \ 155 } while (0) 156 #endif /* (_KERNEL && INVARIANTS) || _STANDALONE */ 157 158 #ifdef _KERNEL 159 /* 160 * Macros for generating panic messages based on the exact condition text. 161 * 162 * NOTE: Use these with care, as the resulting message might omit key 163 * information required to understand the assertion failure. Consult the 164 * MPASS(9) man page for guidance. 165 */ 166 #define MPASS(ex) MPASS4(ex, #ex, __FILE__, __LINE__) 167 #define MPASS2(ex, what) MPASS4(ex, what, __FILE__, __LINE__) 168 #define MPASS3(ex, file, line) MPASS4(ex, #ex, file, line) 169 #define MPASS4(ex, what, file, line) \ 170 KASSERT((ex), ("Assertion %s failed at %s:%d", what, file, line)) 171 172 /* 173 * Assert that a pointer can be loaded from memory atomically. 174 * 175 * This assertion enforces stronger alignment than necessary. For example, 176 * on some architectures, atomicity for unaligned loads will depend on 177 * whether or not the load spans multiple cache lines. 178 */ 179 #define ASSERT_ATOMIC_LOAD_PTR(var, msg) \ 180 KASSERT(sizeof(var) == sizeof(void *) && \ 181 ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg) 182 /* 183 * Assert that a thread is in critical(9) section. 184 */ 185 #define CRITICAL_ASSERT(td) \ 186 KASSERT((td)->td_critnest >= 1, ("Not in critical section")) 187 188 #endif /* _KERNEL */ 189 190 #endif /* _SYS_KASSERT_H_ */ 191