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