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