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
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/kernel.h>
21
22#ifdef CONFIG_BUG
23
24#ifdef CONFIG_GENERIC_BUG
25struct bug_entry {
26#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
27 unsigned long bug_addr;
28#else
29 signed int bug_addr_disp;
30#endif
31#ifdef CONFIG_DEBUG_BUGVERBOSE
32#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
33 const char *file;
34#else
35 signed int file_disp;
36#endif
37 unsigned short line;
38#endif
39 unsigned short flags;
40};
41#endif /* CONFIG_GENERIC_BUG */
42
43/*
44 * Don't use BUG() or BUG_ON() unless there's really no way out; one
45 * example might be detecting data structure corruption in the middle
46 * of an operation that can't be backed out of. If the (sub)system
47 * can somehow continue operating, perhaps with reduced functionality,
48 * it's probably not BUG-worthy.
49 *
50 * If you're tempted to BUG(), think again: is completely giving up
51 * really the *only* solution? There are usually better options, where
52 * users don't need to reboot ASAP and can mostly shut down cleanly.
53 */
54#ifndef HAVE_ARCH_BUG
55#define BUG() do { \
56 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
57 barrier_before_unreachable(); \
58 panic("BUG!"); \
59} while (0)
60#endif
61
62#ifndef HAVE_ARCH_BUG_ON
63#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
64#endif
65
66/*
67 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
68 * significant kernel issues that need prompt attention if they should ever
69 * appear at runtime.
70 *
71 * Do not use these macros when checking for invalid external inputs
72 * (e.g. invalid system call arguments, or invalid data coming from
73 * network/devices), and on transient conditions like ENOMEM or EAGAIN.
74 * These macros should be used for recoverable kernel issues only.
75 * For invalid external inputs, transient conditions, etc use
76 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
77 * Do not include "BUG"/"WARNING" in format strings manually to make these
78 * conditions distinguishable from kernel issues.
79 *
80 * Use the versions with printk format strings to provide better diagnostics.
81 */
82#ifndef __WARN_FLAGS
83extern __printf(4, 5)
84void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
85 const char *fmt, ...);
86#define __WARN() __WARN_printf(TAINT_WARN, NULL)
87#define __WARN_printf(taint, arg...) do { \
88 instrumentation_begin(); \
89 warn_slowpath_fmt(__FILE__, __LINE__, taint, arg); \
90 instrumentation_end(); \
91 } while (0)
92#else
93extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
94#define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
95#define __WARN_printf(taint, arg...) do { \
96 instrumentation_begin(); \
97 __warn_printk(arg); \
98 __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
99 instrumentation_end(); \
100 } while (0)
101#define WARN_ON_ONCE(condition) ({ \
102 int __ret_warn_on = !!(condition); \
103 if (unlikely(__ret_warn_on)) \
104 __WARN_FLAGS(BUGFLAG_ONCE | \
105 BUGFLAG_TAINT(TAINT_WARN)); \
106 unlikely(__ret_warn_on); \
107})
108#endif
109
110/* used internally by panic.c */
111struct warn_args;
112struct pt_regs;
113
114void __warn(const char *file, int line, void *caller, unsigned taint,
115 struct pt_regs *regs, struct warn_args *args);
116
117#ifndef WARN_ON
118#define WARN_ON(condition) ({ \
119 int __ret_warn_on = !!(condition); \
120 if (unlikely(__ret_warn_on)) \
121 __WARN(); \
122 unlikely(__ret_warn_on); \
123})
124#endif
125
126#ifndef WARN
127#define WARN(condition, format...) ({ \
128 int __ret_warn_on = !!(condition); \
129 if (unlikely(__ret_warn_on)) \
130 __WARN_printf(TAINT_WARN, format); \
131 unlikely(__ret_warn_on); \
132})
133#endif
134
135#define WARN_TAINT(condition, taint, format...) ({ \
136 int __ret_warn_on = !!(condition); \
137 if (unlikely(__ret_warn_on)) \
138 __WARN_printf(taint, format); \
139 unlikely(__ret_warn_on); \
140})
141
142#ifndef WARN_ON_ONCE
143#define WARN_ON_ONCE(condition) ({ \
144 static bool __section(".data.once") __warned; \
145 int __ret_warn_once = !!(condition); \
146 \
147 if (unlikely(__ret_warn_once && !__warned)) { \
148 __warned = true; \
149 WARN_ON(1); \
150 } \
151 unlikely(__ret_warn_once); \
152})
153#endif
154
155#define WARN_ONCE(condition, format...) ({ \
156 static bool __section(".data.once") __warned; \
157 int __ret_warn_once = !!(condition); \
158 \
159 if (unlikely(__ret_warn_once && !__warned)) { \
160 __warned = true; \
161 WARN(1, format); \
162 } \
163 unlikely(__ret_warn_once); \
164})
165
166#define WARN_TAINT_ONCE(condition, taint, format...) ({ \
167 static bool __section(".data.once") __warned; \
168 int __ret_warn_once = !!(condition); \
169 \
170 if (unlikely(__ret_warn_once && !__warned)) { \
171 __warned = true; \
172 WARN_TAINT(1, taint, format); \
173 } \
174 unlikely(__ret_warn_once); \
175})
176
177#else /* !CONFIG_BUG */
178#ifndef HAVE_ARCH_BUG
179#define BUG() do {} while (1)
180#endif
181
182#ifndef HAVE_ARCH_BUG_ON
183#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
184#endif
185
186#ifndef HAVE_ARCH_WARN_ON
187#define WARN_ON(condition) ({ \
188 int __ret_warn_on = !!(condition); \
189 unlikely(__ret_warn_on); \
190})
191#endif
192
193#ifndef WARN
194#define WARN(condition, format...) ({ \
195 int __ret_warn_on = !!(condition); \
196 no_printk(format); \
197 unlikely(__ret_warn_on); \
198})
199#endif
200
201#define WARN_ON_ONCE(condition) WARN_ON(condition)
202#define WARN_ONCE(condition, format...) WARN(condition, format)
203#define WARN_TAINT(condition, taint, format...) WARN(condition, format)
204#define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
205
206#endif
207
208/*
209 * WARN_ON_SMP() is for cases that the warning is either
210 * meaningless for !SMP or may even cause failures.
211 * It can also be used with values that are only defined
212 * on SMP:
213 *
214 * struct foo {
215 * [...]
216 * #ifdef CONFIG_SMP
217 * int bar;
218 * #endif
219 * };
220 *
221 * void func(struct foo *zoot)
222 * {
223 * WARN_ON_SMP(!zoot->bar);
224 *
225 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
226 * and should be a nop and return false for uniprocessor.
227 *
228 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
229 * and x is true.
230 */
231#ifdef CONFIG_SMP
232# define WARN_ON_SMP(x) WARN_ON(x)
233#else
234/*
235 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
236 * a stand alone line statement or as a condition in an if ()
237 * statement.
238 * A simple "0" would cause gcc to give a "statement has no effect"
239 * warning.
240 */
241# define WARN_ON_SMP(x) ({0;})
242#endif
243
244/*
245 * WARN_ON_FUNCTION_MISMATCH() warns if a value doesn't match a
246 * function address, and can be useful for catching issues with
247 * callback functions, for example.
248 *
249 * With CONFIG_CFI_CLANG, the warning is disabled because the
250 * compiler replaces function addresses taken in C code with
251 * local jump table addresses, which breaks cross-module function
252 * address equality.
253 */
254#if defined(CONFIG_CFI_CLANG) && defined(CONFIG_MODULES)
255# define WARN_ON_FUNCTION_MISMATCH(x, fn) ({ 0; })
256#else
257# define WARN_ON_FUNCTION_MISMATCH(x, fn) WARN_ON_ONCE((x) != (fn))
258#endif
259
260#endif /* __ASSEMBLY__ */
261
262#endif