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