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() __WARN_TAINT(TAINT_WARN)
108#define __WARN_printf(arg...) do { __warn_printk(arg); __WARN(); } while (0)
109#define __WARN_printf_taint(taint, arg...) \
110 do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
111#endif
112
113/* used internally by panic.c */
114struct warn_args;
115struct pt_regs;
116
117void __warn(const char *file, int line, void *caller, unsigned taint,
118 struct pt_regs *regs, struct warn_args *args);
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(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(taint, format); \
142 unlikely(__ret_warn_on); \
143})
144
145#ifndef WARN_ON_ONCE
146#define WARN_ON_ONCE(condition) ({ \
147 static bool __section(.data.once) __warned; \
148 int __ret_warn_once = !!(condition); \
149 \
150 if (unlikely(__ret_warn_once && !__warned)) { \
151 __warned = true; \
152 WARN_ON(1); \
153 } \
154 unlikely(__ret_warn_once); \
155})
156#endif
157
158#define WARN_ONCE(condition, format...) ({ \
159 static bool __section(.data.once) __warned; \
160 int __ret_warn_once = !!(condition); \
161 \
162 if (unlikely(__ret_warn_once && !__warned)) { \
163 __warned = true; \
164 WARN(1, format); \
165 } \
166 unlikely(__ret_warn_once); \
167})
168
169#define WARN_TAINT_ONCE(condition, taint, format...) ({ \
170 static bool __section(.data.once) __warned; \
171 int __ret_warn_once = !!(condition); \
172 \
173 if (unlikely(__ret_warn_once && !__warned)) { \
174 __warned = true; \
175 WARN_TAINT(1, taint, format); \
176 } \
177 unlikely(__ret_warn_once); \
178})
179
180#else /* !CONFIG_BUG */
181#ifndef HAVE_ARCH_BUG
182#define BUG() do {} while (1)
183#endif
184
185#ifndef HAVE_ARCH_BUG_ON
186#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
187#endif
188
189#ifndef HAVE_ARCH_WARN_ON
190#define WARN_ON(condition) ({ \
191 int __ret_warn_on = !!(condition); \
192 unlikely(__ret_warn_on); \
193})
194#endif
195
196#ifndef WARN
197#define WARN(condition, format...) ({ \
198 int __ret_warn_on = !!(condition); \
199 no_printk(format); \
200 unlikely(__ret_warn_on); \
201})
202#endif
203
204#define WARN_ON_ONCE(condition) WARN_ON(condition)
205#define WARN_ONCE(condition, format...) WARN(condition, format)
206#define WARN_TAINT(condition, taint, format...) WARN(condition, format)
207#define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
208
209#endif
210
211/*
212 * WARN_ON_SMP() is for cases that the warning is either
213 * meaningless for !SMP or may even cause failures.
214 * It can also be used with values that are only defined
215 * on SMP:
216 *
217 * struct foo {
218 * [...]
219 * #ifdef CONFIG_SMP
220 * int bar;
221 * #endif
222 * };
223 *
224 * void func(struct foo *zoot)
225 * {
226 * WARN_ON_SMP(!zoot->bar);
227 *
228 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
229 * and should be a nop and return false for uniprocessor.
230 *
231 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
232 * and x is true.
233 */
234#ifdef CONFIG_SMP
235# define WARN_ON_SMP(x) WARN_ON(x)
236#else
237/*
238 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
239 * a stand alone line statement or as a condition in an if ()
240 * statement.
241 * A simple "0" would cause gcc to give a "statement has no effect"
242 * warning.
243 */
244# define WARN_ON_SMP(x) ({0;})
245#endif
246
247#endif /* __ASSEMBLY__ */
248
249#endif
250