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