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