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/panic.h> 21 #include <linux/printk.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 static bool __section(".data.once") __warned; \ 146 int __ret_warn_once = !!(condition); \ 147 \ 148 if (unlikely(__ret_warn_once && !__warned)) { \ 149 __warned = true; \ 150 WARN_ON(1); \ 151 } \ 152 unlikely(__ret_warn_once); \ 153 }) 154 #endif 155 156 #define WARN_ONCE(condition, format...) ({ \ 157 static bool __section(".data.once") __warned; \ 158 int __ret_warn_once = !!(condition); \ 159 \ 160 if (unlikely(__ret_warn_once && !__warned)) { \ 161 __warned = true; \ 162 WARN(1, format); \ 163 } \ 164 unlikely(__ret_warn_once); \ 165 }) 166 167 #define WARN_TAINT_ONCE(condition, taint, format...) ({ \ 168 static bool __section(".data.once") __warned; \ 169 int __ret_warn_once = !!(condition); \ 170 \ 171 if (unlikely(__ret_warn_once && !__warned)) { \ 172 __warned = true; \ 173 WARN_TAINT(1, taint, format); \ 174 } \ 175 unlikely(__ret_warn_once); \ 176 }) 177 178 #else /* !CONFIG_BUG */ 179 #ifndef HAVE_ARCH_BUG 180 #define BUG() do {} while (1) 181 #endif 182 183 #ifndef HAVE_ARCH_BUG_ON 184 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 185 #endif 186 187 #ifndef HAVE_ARCH_WARN_ON 188 #define WARN_ON(condition) ({ \ 189 int __ret_warn_on = !!(condition); \ 190 unlikely(__ret_warn_on); \ 191 }) 192 #endif 193 194 #ifndef WARN 195 #define WARN(condition, format...) ({ \ 196 int __ret_warn_on = !!(condition); \ 197 no_printk(format); \ 198 unlikely(__ret_warn_on); \ 199 }) 200 #endif 201 202 #define WARN_ON_ONCE(condition) WARN_ON(condition) 203 #define WARN_ONCE(condition, format...) WARN(condition, format) 204 #define WARN_TAINT(condition, taint, format...) WARN(condition, format) 205 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format) 206 207 #endif 208 209 /* 210 * WARN_ON_SMP() is for cases that the warning is either 211 * meaningless for !SMP or may even cause failures. 212 * It can also be used with values that are only defined 213 * on SMP: 214 * 215 * struct foo { 216 * [...] 217 * #ifdef CONFIG_SMP 218 * int bar; 219 * #endif 220 * }; 221 * 222 * void func(struct foo *zoot) 223 * { 224 * WARN_ON_SMP(!zoot->bar); 225 * 226 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), 227 * and should be a nop and return false for uniprocessor. 228 * 229 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set 230 * and x is true. 231 */ 232 #ifdef CONFIG_SMP 233 # define WARN_ON_SMP(x) WARN_ON(x) 234 #else 235 /* 236 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as 237 * a stand alone line statement or as a condition in an if () 238 * statement. 239 * A simple "0" would cause gcc to give a "statement has no effect" 240 * warning. 241 */ 242 # define WARN_ON_SMP(x) ({0;}) 243 #endif 244 245 /* 246 * WARN_ON_FUNCTION_MISMATCH() warns if a value doesn't match a 247 * function address, and can be useful for catching issues with 248 * callback functions, for example. 249 * 250 * With CONFIG_CFI_CLANG, the warning is disabled because the 251 * compiler replaces function addresses taken in C code with 252 * local jump table addresses, which breaks cross-module function 253 * address equality. 254 */ 255 #if defined(CONFIG_CFI_CLANG) && defined(CONFIG_MODULES) 256 # define WARN_ON_FUNCTION_MISMATCH(x, fn) ({ 0; }) 257 #else 258 # define WARN_ON_FUNCTION_MISMATCH(x, fn) WARN_ON_ONCE((x) != (fn)) 259 #endif 260 261 #endif /* __ASSEMBLY__ */ 262 263 #endif 264