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 8 #define CUT_HERE "------------[ cut here ]------------\n" 9 10 #ifdef CONFIG_GENERIC_BUG 11 #define BUGFLAG_WARNING (1 << 0) 12 #define BUGFLAG_ONCE (1 << 1) 13 #define BUGFLAG_DONE (1 << 2) 14 #define BUGFLAG_NO_CUT_HERE (1 << 3) /* CUT_HERE already sent */ 15 #define BUGFLAG_TAINT(taint) ((taint) << 8) 16 #define BUG_GET_TAINT(bug) ((bug)->flags >> 8) 17 #endif 18 19 #ifndef __ASSEMBLY__ 20 #include <linux/kernel.h> 21 22 #ifdef CONFIG_BUG 23 24 #ifdef CONFIG_GENERIC_BUG 25 struct bug_entry { 26 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 27 unsigned long bug_addr; 28 #else 29 signed int bug_addr_disp; 30 #endif 31 #ifdef CONFIG_DEBUG_BUGVERBOSE 32 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 33 const char *file; 34 #else 35 signed int file_disp; 36 #endif 37 unsigned short line; 38 #endif 39 unsigned short flags; 40 }; 41 #endif /* CONFIG_GENERIC_BUG */ 42 43 /* 44 * Don't use BUG() or BUG_ON() unless there's really no way out; one 45 * example might be detecting data structure corruption in the middle 46 * of an operation that can't be backed out of. If the (sub)system 47 * can somehow continue operating, perhaps with reduced functionality, 48 * it's probably not BUG-worthy. 49 * 50 * If you're tempted to BUG(), think again: is completely giving up 51 * really the *only* solution? There are usually better options, where 52 * users don't need to reboot ASAP and can mostly shut down cleanly. 53 */ 54 #ifndef HAVE_ARCH_BUG 55 #define BUG() do { \ 56 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \ 57 barrier_before_unreachable(); \ 58 panic("BUG!"); \ 59 } while (0) 60 #endif 61 62 #ifndef HAVE_ARCH_BUG_ON 63 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 64 #endif 65 66 /* 67 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report 68 * significant kernel issues that need prompt attention if they should ever 69 * appear at runtime. 70 * 71 * Do not use these macros when checking for invalid external inputs 72 * (e.g. invalid system call arguments, or invalid data coming from 73 * network/devices), and on transient conditions like ENOMEM or EAGAIN. 74 * These macros should be used for recoverable kernel issues only. 75 * For invalid external inputs, transient conditions, etc use 76 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary. 77 * Do not include "BUG"/"WARNING" in format strings manually to make these 78 * conditions distinguishable from kernel issues. 79 * 80 * Use the versions with printk format strings to provide better diagnostics. 81 */ 82 #ifndef __WARN_FLAGS 83 extern __printf(4, 5) 84 void warn_slowpath_fmt(const char *file, const int line, unsigned taint, 85 const char *fmt, ...); 86 #define __WARN() __WARN_printf(TAINT_WARN, NULL) 87 #define __WARN_printf(taint, arg...) do { \ 88 instrumentation_begin(); \ 89 warn_slowpath_fmt(__FILE__, __LINE__, taint, arg); \ 90 instrumentation_end(); \ 91 } while (0) 92 #else 93 extern __printf(1, 2) void __warn_printk(const char *fmt, ...); 94 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN)) 95 #define __WARN_printf(taint, arg...) do { \ 96 instrumentation_begin(); \ 97 __warn_printk(arg); \ 98 __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\ 99 instrumentation_end(); \ 100 } while (0) 101 #define WARN_ON_ONCE(condition) ({ \ 102 int __ret_warn_on = !!(condition); \ 103 if (unlikely(__ret_warn_on)) \ 104 __WARN_FLAGS(BUGFLAG_ONCE | \ 105 BUGFLAG_TAINT(TAINT_WARN)); \ 106 unlikely(__ret_warn_on); \ 107 }) 108 #endif 109 110 /* used internally by panic.c */ 111 struct warn_args; 112 struct pt_regs; 113 114 void __warn(const char *file, int line, void *caller, unsigned taint, 115 struct pt_regs *regs, struct warn_args *args); 116 117 #ifndef WARN_ON 118 #define WARN_ON(condition) ({ \ 119 int __ret_warn_on = !!(condition); \ 120 if (unlikely(__ret_warn_on)) \ 121 __WARN(); \ 122 unlikely(__ret_warn_on); \ 123 }) 124 #endif 125 126 #ifndef WARN 127 #define WARN(condition, format...) ({ \ 128 int __ret_warn_on = !!(condition); \ 129 if (unlikely(__ret_warn_on)) \ 130 __WARN_printf(TAINT_WARN, format); \ 131 unlikely(__ret_warn_on); \ 132 }) 133 #endif 134 135 #define WARN_TAINT(condition, taint, format...) ({ \ 136 int __ret_warn_on = !!(condition); \ 137 if (unlikely(__ret_warn_on)) \ 138 __WARN_printf(taint, format); \ 139 unlikely(__ret_warn_on); \ 140 }) 141 142 #ifndef WARN_ON_ONCE 143 #define WARN_ON_ONCE(condition) ({ \ 144 static bool __section(".data.once") __warned; \ 145 int __ret_warn_once = !!(condition); \ 146 \ 147 if (unlikely(__ret_warn_once && !__warned)) { \ 148 __warned = true; \ 149 WARN_ON(1); \ 150 } \ 151 unlikely(__ret_warn_once); \ 152 }) 153 #endif 154 155 #define WARN_ONCE(condition, format...) ({ \ 156 static bool __section(".data.once") __warned; \ 157 int __ret_warn_once = !!(condition); \ 158 \ 159 if (unlikely(__ret_warn_once && !__warned)) { \ 160 __warned = true; \ 161 WARN(1, format); \ 162 } \ 163 unlikely(__ret_warn_once); \ 164 }) 165 166 #define WARN_TAINT_ONCE(condition, taint, format...) ({ \ 167 static bool __section(".data.once") __warned; \ 168 int __ret_warn_once = !!(condition); \ 169 \ 170 if (unlikely(__ret_warn_once && !__warned)) { \ 171 __warned = true; \ 172 WARN_TAINT(1, taint, format); \ 173 } \ 174 unlikely(__ret_warn_once); \ 175 }) 176 177 #else /* !CONFIG_BUG */ 178 #ifndef HAVE_ARCH_BUG 179 #define BUG() do {} while (1) 180 #endif 181 182 #ifndef HAVE_ARCH_BUG_ON 183 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 184 #endif 185 186 #ifndef HAVE_ARCH_WARN_ON 187 #define WARN_ON(condition) ({ \ 188 int __ret_warn_on = !!(condition); \ 189 unlikely(__ret_warn_on); \ 190 }) 191 #endif 192 193 #ifndef WARN 194 #define WARN(condition, format...) ({ \ 195 int __ret_warn_on = !!(condition); \ 196 no_printk(format); \ 197 unlikely(__ret_warn_on); \ 198 }) 199 #endif 200 201 #define WARN_ON_ONCE(condition) WARN_ON(condition) 202 #define WARN_ONCE(condition, format...) WARN(condition, format) 203 #define WARN_TAINT(condition, taint, format...) WARN(condition, format) 204 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format) 205 206 #endif 207 208 /* 209 * WARN_ON_SMP() is for cases that the warning is either 210 * meaningless for !SMP or may even cause failures. 211 * It can also be used with values that are only defined 212 * on SMP: 213 * 214 * struct foo { 215 * [...] 216 * #ifdef CONFIG_SMP 217 * int bar; 218 * #endif 219 * }; 220 * 221 * void func(struct foo *zoot) 222 * { 223 * WARN_ON_SMP(!zoot->bar); 224 * 225 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), 226 * and should be a nop and return false for uniprocessor. 227 * 228 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set 229 * and x is true. 230 */ 231 #ifdef CONFIG_SMP 232 # define WARN_ON_SMP(x) WARN_ON(x) 233 #else 234 /* 235 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as 236 * a stand alone line statement or as a condition in an if () 237 * statement. 238 * A simple "0" would cause gcc to give a "statement has no effect" 239 * warning. 240 */ 241 # define WARN_ON_SMP(x) ({0;}) 242 #endif 243 244 #endif /* __ASSEMBLY__ */ 245 246 #endif 247