1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_GENERIC_BUG_H 3 #define _ASM_GENERIC_BUG_H 4 5 #include <linux/compiler.h> 6 #include <linux/instrumentation.h> 7 #include <linux/once_lite.h> 8 9 #define CUT_HERE "------------[ cut here ]------------\n" 10 11 #ifdef CONFIG_GENERIC_BUG 12 #define BUGFLAG_WARNING (1 << 0) 13 #define BUGFLAG_ONCE (1 << 1) 14 #define BUGFLAG_DONE (1 << 2) 15 #define BUGFLAG_NO_CUT_HERE (1 << 3) /* CUT_HERE already sent */ 16 #define BUGFLAG_TAINT(taint) ((taint) << 8) 17 #define BUG_GET_TAINT(bug) ((bug)->flags >> 8) 18 #endif 19 20 #ifndef __ASSEMBLY__ 21 #include <linux/panic.h> 22 #include <linux/printk.h> 23 24 #ifdef CONFIG_BUG 25 26 #ifdef CONFIG_GENERIC_BUG 27 struct bug_entry { 28 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 29 unsigned long bug_addr; 30 #else 31 signed int bug_addr_disp; 32 #endif 33 #ifdef CONFIG_DEBUG_BUGVERBOSE 34 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 35 const char *file; 36 #else 37 signed int file_disp; 38 #endif 39 unsigned short line; 40 #endif 41 unsigned short flags; 42 }; 43 #endif /* CONFIG_GENERIC_BUG */ 44 45 /* 46 * Don't use BUG() or BUG_ON() unless there's really no way out; one 47 * example might be detecting data structure corruption in the middle 48 * of an operation that can't be backed out of. If the (sub)system 49 * can somehow continue operating, perhaps with reduced functionality, 50 * it's probably not BUG-worthy. 51 * 52 * If you're tempted to BUG(), think again: is completely giving up 53 * really the *only* solution? There are usually better options, where 54 * users don't need to reboot ASAP and can mostly shut down cleanly. 55 */ 56 #ifndef HAVE_ARCH_BUG 57 #define BUG() do { \ 58 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \ 59 barrier_before_unreachable(); \ 60 panic("BUG!"); \ 61 } while (0) 62 #endif 63 64 #ifndef HAVE_ARCH_BUG_ON 65 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 66 #endif 67 68 /* 69 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report 70 * significant kernel issues that need prompt attention if they should ever 71 * appear at runtime. 72 * 73 * Do not use these macros when checking for invalid external inputs 74 * (e.g. invalid system call arguments, or invalid data coming from 75 * network/devices), and on transient conditions like ENOMEM or EAGAIN. 76 * These macros should be used for recoverable kernel issues only. 77 * For invalid external inputs, transient conditions, etc use 78 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary. 79 * Do not include "BUG"/"WARNING" in format strings manually to make these 80 * conditions distinguishable from kernel issues. 81 * 82 * Use the versions with printk format strings to provide better diagnostics. 83 */ 84 #ifndef __WARN_FLAGS 85 extern __printf(4, 5) 86 void warn_slowpath_fmt(const char *file, const int line, unsigned taint, 87 const char *fmt, ...); 88 #define __WARN() __WARN_printf(TAINT_WARN, NULL) 89 #define __WARN_printf(taint, arg...) do { \ 90 instrumentation_begin(); \ 91 warn_slowpath_fmt(__FILE__, __LINE__, taint, arg); \ 92 instrumentation_end(); \ 93 } while (0) 94 #else 95 extern __printf(1, 2) void __warn_printk(const char *fmt, ...); 96 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN)) 97 #define __WARN_printf(taint, arg...) do { \ 98 instrumentation_begin(); \ 99 __warn_printk(arg); \ 100 __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\ 101 instrumentation_end(); \ 102 } while (0) 103 #define WARN_ON_ONCE(condition) ({ \ 104 int __ret_warn_on = !!(condition); \ 105 if (unlikely(__ret_warn_on)) \ 106 __WARN_FLAGS(BUGFLAG_ONCE | \ 107 BUGFLAG_TAINT(TAINT_WARN)); \ 108 unlikely(__ret_warn_on); \ 109 }) 110 #endif 111 112 /* used internally by panic.c */ 113 struct warn_args; 114 struct pt_regs; 115 116 void __warn(const char *file, int line, void *caller, unsigned taint, 117 struct pt_regs *regs, struct warn_args *args); 118 119 #ifndef WARN_ON 120 #define WARN_ON(condition) ({ \ 121 int __ret_warn_on = !!(condition); \ 122 if (unlikely(__ret_warn_on)) \ 123 __WARN(); \ 124 unlikely(__ret_warn_on); \ 125 }) 126 #endif 127 128 #ifndef WARN 129 #define WARN(condition, format...) ({ \ 130 int __ret_warn_on = !!(condition); \ 131 if (unlikely(__ret_warn_on)) \ 132 __WARN_printf(TAINT_WARN, format); \ 133 unlikely(__ret_warn_on); \ 134 }) 135 #endif 136 137 #define WARN_TAINT(condition, taint, format...) ({ \ 138 int __ret_warn_on = !!(condition); \ 139 if (unlikely(__ret_warn_on)) \ 140 __WARN_printf(taint, format); \ 141 unlikely(__ret_warn_on); \ 142 }) 143 144 #ifndef WARN_ON_ONCE 145 #define WARN_ON_ONCE(condition) \ 146 DO_ONCE_LITE_IF(condition, WARN_ON, 1) 147 #endif 148 149 #define WARN_ONCE(condition, format...) \ 150 DO_ONCE_LITE_IF(condition, WARN, 1, format) 151 152 #define WARN_TAINT_ONCE(condition, taint, format...) \ 153 DO_ONCE_LITE_IF(condition, WARN_TAINT, 1, taint, format) 154 155 #else /* !CONFIG_BUG */ 156 #ifndef HAVE_ARCH_BUG 157 #define BUG() do {} while (1) 158 #endif 159 160 #ifndef HAVE_ARCH_BUG_ON 161 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 162 #endif 163 164 #ifndef HAVE_ARCH_WARN_ON 165 #define WARN_ON(condition) ({ \ 166 int __ret_warn_on = !!(condition); \ 167 unlikely(__ret_warn_on); \ 168 }) 169 #endif 170 171 #ifndef WARN 172 #define WARN(condition, format...) ({ \ 173 int __ret_warn_on = !!(condition); \ 174 no_printk(format); \ 175 unlikely(__ret_warn_on); \ 176 }) 177 #endif 178 179 #define WARN_ON_ONCE(condition) WARN_ON(condition) 180 #define WARN_ONCE(condition, format...) WARN(condition, format) 181 #define WARN_TAINT(condition, taint, format...) WARN(condition, format) 182 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format) 183 184 #endif 185 186 /* 187 * WARN_ON_SMP() is for cases that the warning is either 188 * meaningless for !SMP or may even cause failures. 189 * It can also be used with values that are only defined 190 * on SMP: 191 * 192 * struct foo { 193 * [...] 194 * #ifdef CONFIG_SMP 195 * int bar; 196 * #endif 197 * }; 198 * 199 * void func(struct foo *zoot) 200 * { 201 * WARN_ON_SMP(!zoot->bar); 202 * 203 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), 204 * and should be a nop and return false for uniprocessor. 205 * 206 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set 207 * and x is true. 208 */ 209 #ifdef CONFIG_SMP 210 # define WARN_ON_SMP(x) WARN_ON(x) 211 #else 212 /* 213 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as 214 * a stand alone line statement or as a condition in an if () 215 * statement. 216 * A simple "0" would cause gcc to give a "statement has no effect" 217 * warning. 218 */ 219 # define WARN_ON_SMP(x) ({0;}) 220 #endif 221 222 /* 223 * WARN_ON_FUNCTION_MISMATCH() warns if a value doesn't match a 224 * function address, and can be useful for catching issues with 225 * callback functions, for example. 226 * 227 * With CONFIG_CFI_CLANG, the warning is disabled because the 228 * compiler replaces function addresses taken in C code with 229 * local jump table addresses, which breaks cross-module function 230 * address equality. 231 */ 232 #if defined(CONFIG_CFI_CLANG) && defined(CONFIG_MODULES) 233 # define WARN_ON_FUNCTION_MISMATCH(x, fn) ({ 0; }) 234 #else 235 # define WARN_ON_FUNCTION_MISMATCH(x, fn) WARN_ON_ONCE((x) != (fn)) 236 #endif 237 238 #endif /* __ASSEMBLY__ */ 239 240 #endif 241