xref: /linux/include/asm-generic/bug.h (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
1 #ifndef _ASM_GENERIC_BUG_H
2 #define _ASM_GENERIC_BUG_H
3 
4 #include <linux/compiler.h>
5 
6 #ifdef CONFIG_GENERIC_BUG
7 #define BUGFLAG_WARNING		(1 << 0)
8 #define BUGFLAG_TAINT(taint)	(BUGFLAG_WARNING | ((taint) << 8))
9 #define BUG_GET_TAINT(bug)	((bug)->flags >> 8)
10 #endif
11 
12 #ifndef __ASSEMBLY__
13 #include <linux/kernel.h>
14 
15 #ifdef CONFIG_BUG
16 
17 #ifdef CONFIG_GENERIC_BUG
18 struct bug_entry {
19 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
20 	unsigned long	bug_addr;
21 #else
22 	signed int	bug_addr_disp;
23 #endif
24 #ifdef CONFIG_DEBUG_BUGVERBOSE
25 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
26 	const char	*file;
27 #else
28 	signed int	file_disp;
29 #endif
30 	unsigned short	line;
31 #endif
32 	unsigned short	flags;
33 };
34 #endif	/* CONFIG_GENERIC_BUG */
35 
36 /*
37  * Don't use BUG() or BUG_ON() unless there's really no way out; one
38  * example might be detecting data structure corruption in the middle
39  * of an operation that can't be backed out of.  If the (sub)system
40  * can somehow continue operating, perhaps with reduced functionality,
41  * it's probably not BUG-worthy.
42  *
43  * If you're tempted to BUG(), think again:  is completely giving up
44  * really the *only* solution?  There are usually better options, where
45  * users don't need to reboot ASAP and can mostly shut down cleanly.
46  */
47 #ifndef HAVE_ARCH_BUG
48 #define BUG() do { \
49 	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
50 	panic("BUG!"); \
51 } while (0)
52 #endif
53 
54 #ifndef HAVE_ARCH_BUG_ON
55 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
56 #endif
57 
58 /*
59  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
60  * significant issues that need prompt attention if they should ever
61  * appear at runtime.  Use the versions with printk format strings
62  * to provide better diagnostics.
63  */
64 #ifndef __WARN_TAINT
65 extern __printf(3, 4)
66 void warn_slowpath_fmt(const char *file, const int line,
67 		       const char *fmt, ...);
68 extern __printf(4, 5)
69 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
70 			     const char *fmt, ...);
71 extern void warn_slowpath_null(const char *file, const int line);
72 #define WANT_WARN_ON_SLOWPATH
73 #define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
74 #define __WARN_printf(arg...)	warn_slowpath_fmt(__FILE__, __LINE__, arg)
75 #define __WARN_printf_taint(taint, arg...)				\
76 	warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
77 #else
78 #define __WARN()		__WARN_TAINT(TAINT_WARN)
79 #define __WARN_printf(arg...)	do { printk(arg); __WARN(); } while (0)
80 #define __WARN_printf_taint(taint, arg...)				\
81 	do { printk(arg); __WARN_TAINT(taint); } while (0)
82 #endif
83 
84 #ifndef WARN_ON
85 #define WARN_ON(condition) ({						\
86 	int __ret_warn_on = !!(condition);				\
87 	if (unlikely(__ret_warn_on))					\
88 		__WARN();						\
89 	unlikely(__ret_warn_on);					\
90 })
91 #endif
92 
93 #ifndef WARN
94 #define WARN(condition, format...) ({						\
95 	int __ret_warn_on = !!(condition);				\
96 	if (unlikely(__ret_warn_on))					\
97 		__WARN_printf(format);					\
98 	unlikely(__ret_warn_on);					\
99 })
100 #endif
101 
102 #define WARN_TAINT(condition, taint, format...) ({			\
103 	int __ret_warn_on = !!(condition);				\
104 	if (unlikely(__ret_warn_on))					\
105 		__WARN_printf_taint(taint, format);			\
106 	unlikely(__ret_warn_on);					\
107 })
108 
109 #define WARN_ON_ONCE(condition)	({				\
110 	static bool __section(.data.unlikely) __warned;		\
111 	int __ret_warn_once = !!(condition);			\
112 								\
113 	if (unlikely(__ret_warn_once))				\
114 		if (WARN_ON(!__warned)) 			\
115 			__warned = true;			\
116 	unlikely(__ret_warn_once);				\
117 })
118 
119 #define WARN_ONCE(condition, format...)	({			\
120 	static bool __section(.data.unlikely) __warned;		\
121 	int __ret_warn_once = !!(condition);			\
122 								\
123 	if (unlikely(__ret_warn_once))				\
124 		if (WARN(!__warned, format)) 			\
125 			__warned = true;			\
126 	unlikely(__ret_warn_once);				\
127 })
128 
129 #define WARN_TAINT_ONCE(condition, taint, format...)	({	\
130 	static bool __section(.data.unlikely) __warned;		\
131 	int __ret_warn_once = !!(condition);			\
132 								\
133 	if (unlikely(__ret_warn_once))				\
134 		if (WARN_TAINT(!__warned, taint, format))	\
135 			__warned = true;			\
136 	unlikely(__ret_warn_once);				\
137 })
138 
139 #else /* !CONFIG_BUG */
140 #ifndef HAVE_ARCH_BUG
141 #define BUG() do {} while (1)
142 #endif
143 
144 #ifndef HAVE_ARCH_BUG_ON
145 #define BUG_ON(condition) do { if (condition) ; } while (0)
146 #endif
147 
148 #ifndef HAVE_ARCH_WARN_ON
149 #define WARN_ON(condition) ({						\
150 	int __ret_warn_on = !!(condition);				\
151 	unlikely(__ret_warn_on);					\
152 })
153 #endif
154 
155 #ifndef WARN
156 #define WARN(condition, format...) ({					\
157 	int __ret_warn_on = !!(condition);				\
158 	no_printk(format);						\
159 	unlikely(__ret_warn_on);					\
160 })
161 #endif
162 
163 #define WARN_ON_ONCE(condition) WARN_ON(condition)
164 #define WARN_ONCE(condition, format...) WARN(condition, format)
165 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
166 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
167 
168 #endif
169 
170 /*
171  * WARN_ON_SMP() is for cases that the warning is either
172  * meaningless for !SMP or may even cause failures.
173  * This is usually used for cases that we have
174  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
175  * returns 0 for uniprocessor settings.
176  * It can also be used with values that are only defined
177  * on SMP:
178  *
179  * struct foo {
180  *  [...]
181  * #ifdef CONFIG_SMP
182  *	int bar;
183  * #endif
184  * };
185  *
186  * void func(struct foo *zoot)
187  * {
188  *	WARN_ON_SMP(!zoot->bar);
189  *
190  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
191  * and should be a nop and return false for uniprocessor.
192  *
193  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
194  * and x is true.
195  */
196 #ifdef CONFIG_SMP
197 # define WARN_ON_SMP(x)			WARN_ON(x)
198 #else
199 /*
200  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
201  * a stand alone line statement or as a condition in an if ()
202  * statement.
203  * A simple "0" would cause gcc to give a "statement has no effect"
204  * warning.
205  */
206 # define WARN_ON_SMP(x)			({0;})
207 #endif
208 
209 #endif /* __ASSEMBLY__ */
210 
211 #endif
212