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 issues that need prompt attention if they should ever
79 * appear at runtime. Use the versions with printk format strings
80 * to provide better diagnostics.
81 */
82#ifndef __WARN_TAINT
83extern __printf(3, 4)
84void warn_slowpath_fmt(const char *file, const int line,
85 const char *fmt, ...);
86extern __printf(4, 5)
87void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
88 const char *fmt, ...);
89extern void warn_slowpath_null(const char *file, const int line);
90#define WANT_WARN_ON_SLOWPATH
91#define __WARN() warn_slowpath_null(__FILE__, __LINE__)
92#define __WARN_printf(arg...) warn_slowpath_fmt(__FILE__, __LINE__, arg)
93#define __WARN_printf_taint(taint, arg...) \
94 warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
95#else
96extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
97#define __WARN() __WARN_TAINT(TAINT_WARN)
98#define __WARN_printf(arg...) do { __warn_printk(arg); __WARN(); } while (0)
99#define __WARN_printf_taint(taint, arg...) \
100 do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
101#endif
102
103/* used internally by panic.c */
104struct warn_args;
105struct pt_regs;
106
107void __warn(const char *file, int line, void *caller, unsigned taint,
108 struct pt_regs *regs, struct warn_args *args);
109
110#ifndef WARN_ON
111#define WARN_ON(condition) ({ \
112 int __ret_warn_on = !!(condition); \
113 if (unlikely(__ret_warn_on)) \
114 __WARN(); \
115 unlikely(__ret_warn_on); \
116})
117#endif
118
119#ifndef WARN
120#define WARN(condition, format...) ({ \
121 int __ret_warn_on = !!(condition); \
122 if (unlikely(__ret_warn_on)) \
123 __WARN_printf(format); \
124 unlikely(__ret_warn_on); \
125})
126#endif
127
128#define WARN_TAINT(condition, taint, format...) ({ \
129 int __ret_warn_on = !!(condition); \
130 if (unlikely(__ret_warn_on)) \
131 __WARN_printf_taint(taint, format); \
132 unlikely(__ret_warn_on); \
133})
134
135#ifndef WARN_ON_ONCE
136#define WARN_ON_ONCE(condition) ({ \
137 static bool __section(.data.once) __warned; \
138 int __ret_warn_once = !!(condition); \
139 \
140 if (unlikely(__ret_warn_once && !__warned)) { \
141 __warned = true; \
142 WARN_ON(1); \
143 } \
144 unlikely(__ret_warn_once); \
145})
146#endif
147
148#define WARN_ONCE(condition, format...) ({ \
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(1, format); \
155 } \
156 unlikely(__ret_warn_once); \
157})
158
159#define WARN_TAINT_ONCE(condition, taint, format...) ({ \
160 static bool __section(.data.once) __warned; \
161 int __ret_warn_once = !!(condition); \
162 \
163 if (unlikely(__ret_warn_once && !__warned)) { \
164 __warned = true; \
165 WARN_TAINT(1, taint, format); \
166 } \
167 unlikely(__ret_warn_once); \
168})
169
170#else /* !CONFIG_BUG */
171#ifndef HAVE_ARCH_BUG
172#define BUG() do {} while (1)
173#endif
174
175#ifndef HAVE_ARCH_BUG_ON
176#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
177#endif
178
179#ifndef HAVE_ARCH_WARN_ON
180#define WARN_ON(condition) ({ \
181 int __ret_warn_on = !!(condition); \
182 unlikely(__ret_warn_on); \
183})
184#endif
185
186#ifndef WARN
187#define WARN(condition, format...) ({ \
188 int __ret_warn_on = !!(condition); \
189 no_printk(format); \
190 unlikely(__ret_warn_on); \
191})
192#endif
193
194#define WARN_ON_ONCE(condition) WARN_ON(condition)
195#define WARN_ONCE(condition, format...) WARN(condition, format)
196#define WARN_TAINT(condition, taint, format...) WARN(condition, format)
197#define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
198
199#endif
200
201/*
202 * WARN_ON_SMP() is for cases that the warning is either
203 * meaningless for !SMP or may even cause failures.
204 * This is usually used for cases that we have
205 * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
206 * returns 0 for uniprocessor settings.
207 * It can also be used with values that are only defined
208 * on SMP:
209 *
210 * struct foo {
211 * [...]
212 * #ifdef CONFIG_SMP
213 * int bar;
214 * #endif
215 * };
216 *
217 * void func(struct foo *zoot)
218 * {
219 * WARN_ON_SMP(!zoot->bar);
220 *
221 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
222 * and should be a nop and return false for uniprocessor.
223 *
224 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
225 * and x is true.
226 */
227#ifdef CONFIG_SMP
228# define WARN_ON_SMP(x) WARN_ON(x)
229#else
230/*
231 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
232 * a stand alone line statement or as a condition in an if ()
233 * statement.
234 * A simple "0" would cause gcc to give a "statement has no effect"
235 * warning.
236 */
237# define WARN_ON_SMP(x) ({0;})
238#endif
239
240#endif /* __ASSEMBLY__ */
241
242#endif
243