Linux kernel mirror (for testing)
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linux
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
7#define CUT_HERE "------------[ cut here ]------------\n"
8
9#ifdef CONFIG_GENERIC_BUG
10#define BUGFLAG_WARNING (1 << 0)
11#define BUGFLAG_ONCE (1 << 1)
12#define BUGFLAG_DONE (1 << 2)
13#define BUGFLAG_TAINT(taint) ((taint) << 8)
14#define BUG_GET_TAINT(bug) ((bug)->flags >> 8)
15#endif
16
17#ifndef __ASSEMBLY__
18#include <linux/kernel.h>
19
20#ifdef CONFIG_BUG
21
22#ifdef CONFIG_GENERIC_BUG
23struct bug_entry {
24#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
25 unsigned long bug_addr;
26#else
27 signed int bug_addr_disp;
28#endif
29#ifdef CONFIG_DEBUG_BUGVERBOSE
30#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
31 const char *file;
32#else
33 signed int file_disp;
34#endif
35 unsigned short line;
36#endif
37 unsigned short flags;
38};
39#endif /* CONFIG_GENERIC_BUG */
40
41/*
42 * Don't use BUG() or BUG_ON() unless there's really no way out; one
43 * example might be detecting data structure corruption in the middle
44 * of an operation that can't be backed out of. If the (sub)system
45 * can somehow continue operating, perhaps with reduced functionality,
46 * it's probably not BUG-worthy.
47 *
48 * If you're tempted to BUG(), think again: is completely giving up
49 * really the *only* solution? There are usually better options, where
50 * users don't need to reboot ASAP and can mostly shut down cleanly.
51 */
52#ifndef HAVE_ARCH_BUG
53#define BUG() do { \
54 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
55 barrier_before_unreachable(); \
56 panic("BUG!"); \
57} while (0)
58#endif
59
60#ifndef HAVE_ARCH_BUG_ON
61#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
62#endif
63
64#ifdef __WARN_FLAGS
65#define __WARN_TAINT(taint) __WARN_FLAGS(BUGFLAG_TAINT(taint))
66#define __WARN_ONCE_TAINT(taint) __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
67
68#define WARN_ON_ONCE(condition) ({ \
69 int __ret_warn_on = !!(condition); \
70 if (unlikely(__ret_warn_on)) \
71 __WARN_ONCE_TAINT(TAINT_WARN); \
72 unlikely(__ret_warn_on); \
73})
74#endif
75
76/*
77 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
78 * significant kernel issues that need prompt attention if they should ever
79 * appear at runtime.
80 *
81 * Do not use these macros when checking for invalid external inputs
82 * (e.g. invalid system call arguments, or invalid data coming from
83 * network/devices), and on transient conditions like ENOMEM or EAGAIN.
84 * These macros should be used for recoverable kernel issues only.
85 * For invalid external inputs, transient conditions, etc use
86 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
87 * Do not include "BUG"/"WARNING" in format strings manually to make these
88 * conditions distinguishable from kernel issues.
89 *
90 * Use the versions with printk format strings to provide better diagnostics.
91 */
92#ifndef __WARN_TAINT
93extern __printf(3, 4)
94void warn_slowpath_fmt(const char *file, const int line,
95 const char *fmt, ...);
96extern __printf(4, 5)
97void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
98 const char *fmt, ...);
99extern void warn_slowpath_null(const char *file, const int line);
100#define WANT_WARN_ON_SLOWPATH
101#define __WARN() warn_slowpath_null(__FILE__, __LINE__)
102#define __WARN_printf(arg...) warn_slowpath_fmt(__FILE__, __LINE__, arg)
103#define __WARN_printf_taint(taint, arg...) \
104 warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
105#else
106extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
107#define __WARN() do { \
108 printk(KERN_WARNING CUT_HERE); __WARN_TAINT(TAINT_WARN); \
109} while (0)
110#define __WARN_printf(arg...) __WARN_printf_taint(TAINT_WARN, arg)
111#define __WARN_printf_taint(taint, arg...) \
112 do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
113#endif
114
115/* used internally by panic.c */
116struct warn_args;
117struct pt_regs;
118
119void __warn(const char *file, int line, void *caller, unsigned taint,
120 struct pt_regs *regs, struct warn_args *args);
121
122#ifndef WARN_ON
123#define WARN_ON(condition) ({ \
124 int __ret_warn_on = !!(condition); \
125 if (unlikely(__ret_warn_on)) \
126 __WARN(); \
127 unlikely(__ret_warn_on); \
128})
129#endif
130
131#ifndef WARN
132#define WARN(condition, format...) ({ \
133 int __ret_warn_on = !!(condition); \
134 if (unlikely(__ret_warn_on)) \
135 __WARN_printf(format); \
136 unlikely(__ret_warn_on); \
137})
138#endif
139
140#define WARN_TAINT(condition, taint, format...) ({ \
141 int __ret_warn_on = !!(condition); \
142 if (unlikely(__ret_warn_on)) \
143 __WARN_printf_taint(taint, format); \
144 unlikely(__ret_warn_on); \
145})
146
147#ifndef WARN_ON_ONCE
148#define WARN_ON_ONCE(condition) ({ \
149 static bool __section(.data.once) __warned; \
150 int __ret_warn_once = !!(condition); \
151 \
152 if (unlikely(__ret_warn_once && !__warned)) { \
153 __warned = true; \
154 WARN_ON(1); \
155 } \
156 unlikely(__ret_warn_once); \
157})
158#endif
159
160#define WARN_ONCE(condition, format...) ({ \
161 static bool __section(.data.once) __warned; \
162 int __ret_warn_once = !!(condition); \
163 \
164 if (unlikely(__ret_warn_once && !__warned)) { \
165 __warned = true; \
166 WARN(1, format); \
167 } \
168 unlikely(__ret_warn_once); \
169})
170
171#define WARN_TAINT_ONCE(condition, taint, format...) ({ \
172 static bool __section(.data.once) __warned; \
173 int __ret_warn_once = !!(condition); \
174 \
175 if (unlikely(__ret_warn_once && !__warned)) { \
176 __warned = true; \
177 WARN_TAINT(1, taint, format); \
178 } \
179 unlikely(__ret_warn_once); \
180})
181
182#else /* !CONFIG_BUG */
183#ifndef HAVE_ARCH_BUG
184#define BUG() do {} while (1)
185#endif
186
187#ifndef HAVE_ARCH_BUG_ON
188#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
189#endif
190
191#ifndef HAVE_ARCH_WARN_ON
192#define WARN_ON(condition) ({ \
193 int __ret_warn_on = !!(condition); \
194 unlikely(__ret_warn_on); \
195})
196#endif
197
198#ifndef WARN
199#define WARN(condition, format...) ({ \
200 int __ret_warn_on = !!(condition); \
201 no_printk(format); \
202 unlikely(__ret_warn_on); \
203})
204#endif
205
206#define WARN_ON_ONCE(condition) WARN_ON(condition)
207#define WARN_ONCE(condition, format...) WARN(condition, format)
208#define WARN_TAINT(condition, taint, format...) WARN(condition, format)
209#define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
210
211#endif
212
213/*
214 * WARN_ON_SMP() is for cases that the warning is either
215 * meaningless for !SMP or may even cause failures.
216 * It can also be used with values that are only defined
217 * on SMP:
218 *
219 * struct foo {
220 * [...]
221 * #ifdef CONFIG_SMP
222 * int bar;
223 * #endif
224 * };
225 *
226 * void func(struct foo *zoot)
227 * {
228 * WARN_ON_SMP(!zoot->bar);
229 *
230 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
231 * and should be a nop and return false for uniprocessor.
232 *
233 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
234 * and x is true.
235 */
236#ifdef CONFIG_SMP
237# define WARN_ON_SMP(x) WARN_ON(x)
238#else
239/*
240 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
241 * a stand alone line statement or as a condition in an if ()
242 * statement.
243 * A simple "0" would cause gcc to give a "statement has no effect"
244 * warning.
245 */
246# define WARN_ON_SMP(x) ({0;})
247#endif
248
249#endif /* __ASSEMBLY__ */
250
251#endif