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 #ifndef __WARN_FLAGS 91 extern __printf(4, 5) 92 void warn_slowpath_fmt(const char *file, const int line, unsigned taint, 93 const char *fmt, ...); 94 #define __WARN() __WARN_printf(TAINT_WARN, NULL) 95 #define __WARN_printf(taint, arg...) do { \ 96 instrumentation_begin(); \ 97 warn_slowpath_fmt(__FILE__, __LINE__, taint, arg); \ 98 instrumentation_end(); \ 99 } while (0) 100 #else 101 extern __printf(1, 2) void __warn_printk(const char *fmt, ...); 102 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN)) 103 #define __WARN_printf(taint, arg...) do { \ 104 instrumentation_begin(); \ 105 __warn_printk(arg); \ 106 __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\ 107 instrumentation_end(); \ 108 } while (0) 109 #define WARN_ON_ONCE(condition) ({ \ 110 int __ret_warn_on = !!(condition); \ 111 if (unlikely(__ret_warn_on)) \ 112 __WARN_FLAGS(BUGFLAG_ONCE | \ 113 BUGFLAG_TAINT(TAINT_WARN)); \ 114 unlikely(__ret_warn_on); \ 115 }) 116 #endif 117 118 /* used internally by panic.c */ 119 120 #ifndef WARN_ON 121 #define WARN_ON(condition) ({ \ 122 int __ret_warn_on = !!(condition); \ 123 if (unlikely(__ret_warn_on)) \ 124 __WARN(); \ 125 unlikely(__ret_warn_on); \ 126 }) 127 #endif 128 129 #ifndef WARN 130 #define WARN(condition, format...) ({ \ 131 int __ret_warn_on = !!(condition); \ 132 if (unlikely(__ret_warn_on)) \ 133 __WARN_printf(TAINT_WARN, format); \ 134 unlikely(__ret_warn_on); \ 135 }) 136 #endif 137 138 #define WARN_TAINT(condition, taint, format...) ({ \ 139 int __ret_warn_on = !!(condition); \ 140 if (unlikely(__ret_warn_on)) \ 141 __WARN_printf(taint, format); \ 142 unlikely(__ret_warn_on); \ 143 }) 144 145 #ifndef WARN_ON_ONCE 146 #define WARN_ON_ONCE(condition) \ 147 DO_ONCE_LITE_IF(condition, WARN_ON, 1) 148 #endif 149 150 #define WARN_ONCE(condition, format...) \ 151 DO_ONCE_LITE_IF(condition, WARN, 1, format) 152 153 #define WARN_TAINT_ONCE(condition, taint, format...) \ 154 DO_ONCE_LITE_IF(condition, WARN_TAINT, 1, taint, format) 155 156 #else /* !CONFIG_BUG */ 157 #ifndef HAVE_ARCH_BUG 158 #define BUG() do {} while (1) 159 #endif 160 161 #ifndef HAVE_ARCH_BUG_ON 162 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 163 #endif 164 165 #ifndef HAVE_ARCH_WARN_ON 166 #define WARN_ON(condition) ({ \ 167 int __ret_warn_on = !!(condition); \ 168 unlikely(__ret_warn_on); \ 169 }) 170 #endif 171 172 #ifndef WARN 173 #define WARN(condition, format...) ({ \ 174 int __ret_warn_on = !!(condition); \ 175 no_printk(format); \ 176 unlikely(__ret_warn_on); \ 177 }) 178 #endif 179 180 #define WARN_ON_ONCE(condition) WARN_ON(condition) 181 #define WARN_ONCE(condition, format...) WARN(condition, format) 182 #define WARN_TAINT(condition, taint, format...) WARN(condition, format) 183 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format) 184 185 #endif 186 187 /* 188 * WARN_ON_SMP() is for cases that the warning is either 189 * meaningless for !SMP or may even cause failures. 190 * It can also be used with values that are only defined 191 * on SMP: 192 * 193 * struct foo { 194 * [...] 195 * #ifdef CONFIG_SMP 196 * int bar; 197 * #endif 198 * }; 199 * 200 * void func(struct foo *zoot) 201 * { 202 * WARN_ON_SMP(!zoot->bar); 203 * 204 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), 205 * and should be a nop and return false for uniprocessor. 206 * 207 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set 208 * and x is true. 209 */ 210 #ifdef CONFIG_SMP 211 # define WARN_ON_SMP(x) WARN_ON(x) 212 #else 213 /* 214 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as 215 * a stand alone line statement or as a condition in an if () 216 * statement. 217 * A simple "0" would cause gcc to give a "statement has no effect" 218 * warning. 219 */ 220 # define WARN_ON_SMP(x) ({0;}) 221 #endif 222 223 #endif /* __ASSEMBLY__ */ 224 225 #endif 226