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
24struct warn_args;
25struct pt_regs;
26
27void __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
33struct 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
91extern __printf(4, 5)
92void 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
101extern __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/*
224 * WARN_ON_FUNCTION_MISMATCH() warns if a value doesn't match a
225 * function address, and can be useful for catching issues with
226 * callback functions, for example.
227 *
228 * With CONFIG_CFI_CLANG, the warning is disabled because the
229 * compiler replaces function addresses taken in C code with
230 * local jump table addresses, which breaks cross-module function
231 * address equality.
232 */
233#if defined(CONFIG_CFI_CLANG) && defined(CONFIG_MODULES)
234# define WARN_ON_FUNCTION_MISMATCH(x, fn) ({ 0; })
235#else
236# define WARN_ON_FUNCTION_MISMATCH(x, fn) WARN_ON_ONCE((x) != (fn))
237#endif
238
239#endif /* __ASSEMBLY__ */
240
241#endif
242

source code of linux/include/asm-generic/bug.h