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 7 #define CUT_HERE "------------[ cut here ]------------\n" 8 9 #ifdef CONFIG_GENERIC_BUG 10 #define BUGFLAG_WARNING (1 << 0) 11 #define BUGFLAG_ONCE (1 << 1) 12 #define BUGFLAG_DONE (1 << 2) 13 #define BUGFLAG_TAINT(taint) ((taint) << 8) 14 #define BUG_GET_TAINT(bug) ((bug)->flags >> 8) 15 #endif 16 17 #ifndef __ASSEMBLY__ 18 #include <linux/kernel.h> 19 20 #ifdef CONFIG_BUG 21 22 #ifdef CONFIG_GENERIC_BUG 23 struct bug_entry { 24 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 25 unsigned long bug_addr; 26 #else 27 signed int bug_addr_disp; 28 #endif 29 #ifdef CONFIG_DEBUG_BUGVERBOSE 30 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 31 const char *file; 32 #else 33 signed int file_disp; 34 #endif 35 unsigned short line; 36 #endif 37 unsigned short flags; 38 }; 39 #endif /* CONFIG_GENERIC_BUG */ 40 41 /* 42 * Don't use BUG() or BUG_ON() unless there's really no way out; one 43 * example might be detecting data structure corruption in the middle 44 * of an operation that can't be backed out of. If the (sub)system 45 * can somehow continue operating, perhaps with reduced functionality, 46 * it's probably not BUG-worthy. 47 * 48 * If you're tempted to BUG(), think again: is completely giving up 49 * really the *only* solution? There are usually better options, where 50 * users don't need to reboot ASAP and can mostly shut down cleanly. 51 */ 52 #ifndef HAVE_ARCH_BUG 53 #define BUG() do { \ 54 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \ 55 barrier_before_unreachable(); \ 56 panic("BUG!"); \ 57 } while (0) 58 #endif 59 60 #ifndef HAVE_ARCH_BUG_ON 61 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 62 #endif 63 64 /* 65 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report 66 * significant kernel issues that need prompt attention if they should ever 67 * appear at runtime. 68 * 69 * Do not use these macros when checking for invalid external inputs 70 * (e.g. invalid system call arguments, or invalid data coming from 71 * network/devices), and on transient conditions like ENOMEM or EAGAIN. 72 * These macros should be used for recoverable kernel issues only. 73 * For invalid external inputs, transient conditions, etc use 74 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary. 75 * Do not include "BUG"/"WARNING" in format strings manually to make these 76 * conditions distinguishable from kernel issues. 77 * 78 * Use the versions with printk format strings to provide better diagnostics. 79 */ 80 #ifndef __WARN_FLAGS 81 extern __printf(4, 5) 82 void warn_slowpath_fmt(const char *file, const int line, unsigned taint, 83 const char *fmt, ...); 84 #define __WARN() __WARN_printf(TAINT_WARN, NULL) 85 #define __WARN_printf(taint, arg...) \ 86 warn_slowpath_fmt(__FILE__, __LINE__, taint, arg) 87 #else 88 extern __printf(1, 2) void __warn_printk(const char *fmt, ...); 89 #define __WARN() do { \ 90 printk(KERN_WARNING CUT_HERE); \ 91 __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN)); \ 92 } while (0) 93 #define __WARN_printf(taint, arg...) do { \ 94 __warn_printk(arg); \ 95 __WARN_FLAGS(BUGFLAG_TAINT(taint)); \ 96 } while (0) 97 #define WARN_ON_ONCE(condition) ({ \ 98 int __ret_warn_on = !!(condition); \ 99 if (unlikely(__ret_warn_on)) \ 100 __WARN_FLAGS(BUGFLAG_ONCE | \ 101 BUGFLAG_TAINT(TAINT_WARN)); \ 102 unlikely(__ret_warn_on); \ 103 }) 104 #endif 105 106 /* used internally by panic.c */ 107 struct warn_args; 108 struct pt_regs; 109 110 void __warn(const char *file, int line, void *caller, unsigned taint, 111 struct pt_regs *regs, struct warn_args *args); 112 113 #ifndef WARN_ON 114 #define WARN_ON(condition) ({ \ 115 int __ret_warn_on = !!(condition); \ 116 if (unlikely(__ret_warn_on)) \ 117 __WARN(); \ 118 unlikely(__ret_warn_on); \ 119 }) 120 #endif 121 122 #ifndef WARN 123 #define WARN(condition, format...) ({ \ 124 int __ret_warn_on = !!(condition); \ 125 if (unlikely(__ret_warn_on)) \ 126 __WARN_printf(TAINT_WARN, format); \ 127 unlikely(__ret_warn_on); \ 128 }) 129 #endif 130 131 #define WARN_TAINT(condition, taint, format...) ({ \ 132 int __ret_warn_on = !!(condition); \ 133 if (unlikely(__ret_warn_on)) \ 134 __WARN_printf(taint, format); \ 135 unlikely(__ret_warn_on); \ 136 }) 137 138 #ifndef WARN_ON_ONCE 139 #define WARN_ON_ONCE(condition) ({ \ 140 static bool __section(.data.once) __warned; \ 141 int __ret_warn_once = !!(condition); \ 142 \ 143 if (unlikely(__ret_warn_once && !__warned)) { \ 144 __warned = true; \ 145 WARN_ON(1); \ 146 } \ 147 unlikely(__ret_warn_once); \ 148 }) 149 #endif 150 151 #define WARN_ONCE(condition, format...) ({ \ 152 static bool __section(.data.once) __warned; \ 153 int __ret_warn_once = !!(condition); \ 154 \ 155 if (unlikely(__ret_warn_once && !__warned)) { \ 156 __warned = true; \ 157 WARN(1, format); \ 158 } \ 159 unlikely(__ret_warn_once); \ 160 }) 161 162 #define WARN_TAINT_ONCE(condition, taint, format...) ({ \ 163 static bool __section(.data.once) __warned; \ 164 int __ret_warn_once = !!(condition); \ 165 \ 166 if (unlikely(__ret_warn_once && !__warned)) { \ 167 __warned = true; \ 168 WARN_TAINT(1, taint, format); \ 169 } \ 170 unlikely(__ret_warn_once); \ 171 }) 172 173 #else /* !CONFIG_BUG */ 174 #ifndef HAVE_ARCH_BUG 175 #define BUG() do {} while (1) 176 #endif 177 178 #ifndef HAVE_ARCH_BUG_ON 179 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 180 #endif 181 182 #ifndef HAVE_ARCH_WARN_ON 183 #define WARN_ON(condition) ({ \ 184 int __ret_warn_on = !!(condition); \ 185 unlikely(__ret_warn_on); \ 186 }) 187 #endif 188 189 #ifndef WARN 190 #define WARN(condition, format...) ({ \ 191 int __ret_warn_on = !!(condition); \ 192 no_printk(format); \ 193 unlikely(__ret_warn_on); \ 194 }) 195 #endif 196 197 #define WARN_ON_ONCE(condition) WARN_ON(condition) 198 #define WARN_ONCE(condition, format...) WARN(condition, format) 199 #define WARN_TAINT(condition, taint, format...) WARN(condition, format) 200 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format) 201 202 #endif 203 204 /* 205 * WARN_ON_SMP() is for cases that the warning is either 206 * meaningless for !SMP or may even cause failures. 207 * It can also be used with values that are only defined 208 * on SMP: 209 * 210 * struct foo { 211 * [...] 212 * #ifdef CONFIG_SMP 213 * int bar; 214 * #endif 215 * }; 216 * 217 * void func(struct foo *zoot) 218 * { 219 * WARN_ON_SMP(!zoot->bar); 220 * 221 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), 222 * and should be a nop and return false for uniprocessor. 223 * 224 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set 225 * and x is true. 226 */ 227 #ifdef CONFIG_SMP 228 # define WARN_ON_SMP(x) WARN_ON(x) 229 #else 230 /* 231 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as 232 * a stand alone line statement or as a condition in an if () 233 * statement. 234 * A simple "0" would cause gcc to give a "statement has no effect" 235 * warning. 236 */ 237 # define WARN_ON_SMP(x) ({0;}) 238 #endif 239 240 #endif /* __ASSEMBLY__ */ 241 242 #endif 243