xref: /openbmc/linux/include/asm-generic/bug.h (revision 81d67439)
1 #ifndef _ASM_GENERIC_BUG_H
2 #define _ASM_GENERIC_BUG_H
3 
4 #include <linux/compiler.h>
5 
6 #ifdef CONFIG_BUG
7 
8 #ifdef CONFIG_GENERIC_BUG
9 #ifndef __ASSEMBLY__
10 struct bug_entry {
11 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
12 	unsigned long	bug_addr;
13 #else
14 	signed int	bug_addr_disp;
15 #endif
16 #ifdef CONFIG_DEBUG_BUGVERBOSE
17 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
18 	const char	*file;
19 #else
20 	signed int	file_disp;
21 #endif
22 	unsigned short	line;
23 #endif
24 	unsigned short	flags;
25 };
26 #endif		/* __ASSEMBLY__ */
27 
28 #define BUGFLAG_WARNING		(1 << 0)
29 #define BUGFLAG_TAINT(taint)	(BUGFLAG_WARNING | ((taint) << 8))
30 #define BUG_GET_TAINT(bug)	((bug)->flags >> 8)
31 
32 #endif	/* CONFIG_GENERIC_BUG */
33 
34 /*
35  * Don't use BUG() or BUG_ON() unless there's really no way out; one
36  * example might be detecting data structure corruption in the middle
37  * of an operation that can't be backed out of.  If the (sub)system
38  * can somehow continue operating, perhaps with reduced functionality,
39  * it's probably not BUG-worthy.
40  *
41  * If you're tempted to BUG(), think again:  is completely giving up
42  * really the *only* solution?  There are usually better options, where
43  * users don't need to reboot ASAP and can mostly shut down cleanly.
44  */
45 #ifndef HAVE_ARCH_BUG
46 #define BUG() do { \
47 	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
48 	panic("BUG!"); \
49 } while (0)
50 #endif
51 
52 #ifndef HAVE_ARCH_BUG_ON
53 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
54 #endif
55 
56 /*
57  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
58  * significant issues that need prompt attention if they should ever
59  * appear at runtime.  Use the versions with printk format strings
60  * to provide better diagnostics.
61  */
62 #ifndef __WARN_TAINT
63 #ifndef __ASSEMBLY__
64 extern void warn_slowpath_fmt(const char *file, const int line,
65 		const char *fmt, ...) __attribute__((format(printf, 3, 4)));
66 extern void warn_slowpath_fmt_taint(const char *file, const int line,
67 				    unsigned taint, const char *fmt, ...)
68 	__attribute__((format(printf, 4, 5)));
69 extern void warn_slowpath_null(const char *file, const int line);
70 #define WANT_WARN_ON_SLOWPATH
71 #endif
72 #define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
73 #define __WARN_printf(arg...)	warn_slowpath_fmt(__FILE__, __LINE__, arg)
74 #define __WARN_printf_taint(taint, arg...)				\
75 	warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
76 #else
77 #define __WARN()		__WARN_TAINT(TAINT_WARN)
78 #define __WARN_printf(arg...)	do { printk(arg); __WARN(); } while (0)
79 #define __WARN_printf_taint(taint, arg...)				\
80 	do { printk(arg); __WARN_TAINT(taint); } while (0)
81 #endif
82 
83 #ifndef WARN_ON
84 #define WARN_ON(condition) ({						\
85 	int __ret_warn_on = !!(condition);				\
86 	if (unlikely(__ret_warn_on))					\
87 		__WARN();						\
88 	unlikely(__ret_warn_on);					\
89 })
90 #endif
91 
92 #ifndef WARN
93 #define WARN(condition, format...) ({						\
94 	int __ret_warn_on = !!(condition);				\
95 	if (unlikely(__ret_warn_on))					\
96 		__WARN_printf(format);					\
97 	unlikely(__ret_warn_on);					\
98 })
99 #endif
100 
101 #define WARN_TAINT(condition, taint, format...) ({			\
102 	int __ret_warn_on = !!(condition);				\
103 	if (unlikely(__ret_warn_on))					\
104 		__WARN_printf_taint(taint, format);			\
105 	unlikely(__ret_warn_on);					\
106 })
107 
108 #else /* !CONFIG_BUG */
109 #ifndef HAVE_ARCH_BUG
110 #define BUG() do {} while(0)
111 #endif
112 
113 #ifndef HAVE_ARCH_BUG_ON
114 #define BUG_ON(condition) do { if (condition) ; } while(0)
115 #endif
116 
117 #ifndef HAVE_ARCH_WARN_ON
118 #define WARN_ON(condition) ({						\
119 	int __ret_warn_on = !!(condition);				\
120 	unlikely(__ret_warn_on);					\
121 })
122 #endif
123 
124 #ifndef WARN
125 #define WARN(condition, format...) ({					\
126 	int __ret_warn_on = !!(condition);				\
127 	unlikely(__ret_warn_on);					\
128 })
129 #endif
130 
131 #define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
132 
133 #endif
134 
135 #define WARN_ON_ONCE(condition)	({				\
136 	static bool __warned;					\
137 	int __ret_warn_once = !!(condition);			\
138 								\
139 	if (unlikely(__ret_warn_once))				\
140 		if (WARN_ON(!__warned)) 			\
141 			__warned = true;			\
142 	unlikely(__ret_warn_once);				\
143 })
144 
145 #define WARN_ONCE(condition, format...)	({			\
146 	static bool __warned;					\
147 	int __ret_warn_once = !!(condition);			\
148 								\
149 	if (unlikely(__ret_warn_once))				\
150 		if (WARN(!__warned, format)) 			\
151 			__warned = true;			\
152 	unlikely(__ret_warn_once);				\
153 })
154 
155 #define WARN_TAINT_ONCE(condition, taint, format...)	({	\
156 	static bool __warned;					\
157 	int __ret_warn_once = !!(condition);			\
158 								\
159 	if (unlikely(__ret_warn_once))				\
160 		if (WARN_TAINT(!__warned, taint, format))	\
161 			__warned = true;			\
162 	unlikely(__ret_warn_once);				\
163 })
164 
165 /*
166  * WARN_ON_SMP() is for cases that the warning is either
167  * meaningless for !SMP or may even cause failures.
168  * This is usually used for cases that we have
169  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
170  * returns 0 for uniprocessor settings.
171  * It can also be used with values that are only defined
172  * on SMP:
173  *
174  * struct foo {
175  *  [...]
176  * #ifdef CONFIG_SMP
177  *	int bar;
178  * #endif
179  * };
180  *
181  * void func(struct foo *zoot)
182  * {
183  *	WARN_ON_SMP(!zoot->bar);
184  *
185  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
186  * and should be a nop and return false for uniprocessor.
187  *
188  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
189  * and x is true.
190  */
191 #ifdef CONFIG_SMP
192 # define WARN_ON_SMP(x)			WARN_ON(x)
193 #else
194 /*
195  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
196  * a stand alone line statement or as a condition in an if ()
197  * statement.
198  * A simple "0" would cause gcc to give a "statement has no effect"
199  * warning.
200  */
201 # define WARN_ON_SMP(x)			({0;})
202 #endif
203 
204 #endif
205