xref: /openbmc/linux/include/asm-generic/bug.h (revision 0bea2a65)
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
23 struct 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 	panic("BUG!"); \
56 } while (0)
57 #endif
58 
59 #ifndef HAVE_ARCH_BUG_ON
60 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
61 #endif
62 
63 #ifdef __WARN_FLAGS
64 #define __WARN_TAINT(taint)		__WARN_FLAGS(BUGFLAG_TAINT(taint))
65 #define __WARN_ONCE_TAINT(taint)	__WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
66 
67 #define WARN_ON_ONCE(condition) ({				\
68 	int __ret_warn_on = !!(condition);			\
69 	if (unlikely(__ret_warn_on))				\
70 		__WARN_ONCE_TAINT(TAINT_WARN);			\
71 	unlikely(__ret_warn_on);				\
72 })
73 #endif
74 
75 /*
76  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
77  * significant issues that need prompt attention if they should ever
78  * appear at runtime.  Use the versions with printk format strings
79  * to provide better diagnostics.
80  */
81 #ifndef __WARN_TAINT
82 extern __printf(3, 4)
83 void warn_slowpath_fmt(const char *file, const int line,
84 		       const char *fmt, ...);
85 extern __printf(4, 5)
86 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
87 			     const char *fmt, ...);
88 extern void warn_slowpath_null(const char *file, const int line);
89 #define WANT_WARN_ON_SLOWPATH
90 #define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
91 #define __WARN_printf(arg...)	warn_slowpath_fmt(__FILE__, __LINE__, arg)
92 #define __WARN_printf_taint(taint, arg...)				\
93 	warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
94 #else
95 extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
96 #define __WARN()		__WARN_TAINT(TAINT_WARN)
97 #define __WARN_printf(arg...)	do { __warn_printk(arg); __WARN(); } while (0)
98 #define __WARN_printf_taint(taint, arg...)				\
99 	do { __warn_printk(arg); __WARN_TAINT(taint); } while (0)
100 #endif
101 
102 /* used internally by panic.c */
103 struct warn_args;
104 struct pt_regs;
105 
106 void __warn(const char *file, int line, void *caller, unsigned taint,
107 	    struct pt_regs *regs, struct warn_args *args);
108 
109 #ifndef WARN_ON
110 #define WARN_ON(condition) ({						\
111 	int __ret_warn_on = !!(condition);				\
112 	if (unlikely(__ret_warn_on))					\
113 		__WARN();						\
114 	unlikely(__ret_warn_on);					\
115 })
116 #endif
117 
118 #ifndef WARN
119 #define WARN(condition, format...) ({					\
120 	int __ret_warn_on = !!(condition);				\
121 	if (unlikely(__ret_warn_on))					\
122 		__WARN_printf(format);					\
123 	unlikely(__ret_warn_on);					\
124 })
125 #endif
126 
127 #define WARN_TAINT(condition, taint, format...) ({			\
128 	int __ret_warn_on = !!(condition);				\
129 	if (unlikely(__ret_warn_on))					\
130 		__WARN_printf_taint(taint, format);			\
131 	unlikely(__ret_warn_on);					\
132 })
133 
134 #ifndef WARN_ON_ONCE
135 #define WARN_ON_ONCE(condition)	({				\
136 	static bool __section(.data.once) __warned;		\
137 	int __ret_warn_once = !!(condition);			\
138 								\
139 	if (unlikely(__ret_warn_once && !__warned)) {		\
140 		__warned = true;				\
141 		WARN_ON(1);					\
142 	}							\
143 	unlikely(__ret_warn_once);				\
144 })
145 #endif
146 
147 #define WARN_ONCE(condition, format...)	({			\
148 	static bool __section(.data.once) __warned;		\
149 	int __ret_warn_once = !!(condition);			\
150 								\
151 	if (unlikely(__ret_warn_once && !__warned)) {		\
152 		__warned = true;				\
153 		WARN(1, format);				\
154 	}							\
155 	unlikely(__ret_warn_once);				\
156 })
157 
158 #define WARN_TAINT_ONCE(condition, taint, 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_TAINT(1, taint, format);			\
165 	}							\
166 	unlikely(__ret_warn_once);				\
167 })
168 
169 #else /* !CONFIG_BUG */
170 #ifndef HAVE_ARCH_BUG
171 #define BUG() do {} while (1)
172 #endif
173 
174 #ifndef HAVE_ARCH_BUG_ON
175 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
176 #endif
177 
178 #ifndef HAVE_ARCH_WARN_ON
179 #define WARN_ON(condition) ({						\
180 	int __ret_warn_on = !!(condition);				\
181 	unlikely(__ret_warn_on);					\
182 })
183 #endif
184 
185 #ifndef WARN
186 #define WARN(condition, format...) ({					\
187 	int __ret_warn_on = !!(condition);				\
188 	no_printk(format);						\
189 	unlikely(__ret_warn_on);					\
190 })
191 #endif
192 
193 #define WARN_ON_ONCE(condition) WARN_ON(condition)
194 #define WARN_ONCE(condition, format...) WARN(condition, format)
195 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
196 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
197 
198 #endif
199 
200 /*
201  * WARN_ON_SMP() is for cases that the warning is either
202  * meaningless for !SMP or may even cause failures.
203  * This is usually used for cases that we have
204  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
205  * returns 0 for uniprocessor settings.
206  * It can also be used with values that are only defined
207  * on SMP:
208  *
209  * struct foo {
210  *  [...]
211  * #ifdef CONFIG_SMP
212  *	int bar;
213  * #endif
214  * };
215  *
216  * void func(struct foo *zoot)
217  * {
218  *	WARN_ON_SMP(!zoot->bar);
219  *
220  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
221  * and should be a nop and return false for uniprocessor.
222  *
223  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
224  * and x is true.
225  */
226 #ifdef CONFIG_SMP
227 # define WARN_ON_SMP(x)			WARN_ON(x)
228 #else
229 /*
230  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
231  * a stand alone line statement or as a condition in an if ()
232  * statement.
233  * A simple "0" would cause gcc to give a "statement has no effect"
234  * warning.
235  */
236 # define WARN_ON_SMP(x)			({0;})
237 #endif
238 
239 #endif /* __ASSEMBLY__ */
240 
241 #endif
242