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 __printf(3, 4)
65 void warn_slowpath_fmt(const char *file, const int line,
66 		       const char *fmt, ...);
67 extern __printf(4, 5)
68 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
69 			     const char *fmt, ...);
70 extern void warn_slowpath_null(const char *file, const int line);
71 #define WANT_WARN_ON_SLOWPATH
72 #endif
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 #else /* !CONFIG_BUG */
110 #ifndef HAVE_ARCH_BUG
111 #define BUG() do {} while(0)
112 #endif
113 
114 #ifndef HAVE_ARCH_BUG_ON
115 #define BUG_ON(condition) do { if (condition) ; } while(0)
116 #endif
117 
118 #ifndef HAVE_ARCH_WARN_ON
119 #define WARN_ON(condition) ({						\
120 	int __ret_warn_on = !!(condition);				\
121 	unlikely(__ret_warn_on);					\
122 })
123 #endif
124 
125 #ifndef WARN
126 #define WARN(condition, format...) ({					\
127 	int __ret_warn_on = !!(condition);				\
128 	unlikely(__ret_warn_on);					\
129 })
130 #endif
131 
132 #define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
133 
134 #endif
135 
136 #define WARN_ON_ONCE(condition)	({				\
137 	static bool __section(.data.unlikely) __warned;		\
138 	int __ret_warn_once = !!(condition);			\
139 								\
140 	if (unlikely(__ret_warn_once))				\
141 		if (WARN_ON(!__warned)) 			\
142 			__warned = true;			\
143 	unlikely(__ret_warn_once);				\
144 })
145 
146 #define WARN_ONCE(condition, format...)	({			\
147 	static bool __section(.data.unlikely) __warned;		\
148 	int __ret_warn_once = !!(condition);			\
149 								\
150 	if (unlikely(__ret_warn_once))				\
151 		if (WARN(!__warned, format)) 			\
152 			__warned = true;			\
153 	unlikely(__ret_warn_once);				\
154 })
155 
156 #define WARN_TAINT_ONCE(condition, taint, format...)	({	\
157 	static bool __section(.data.unlikely) __warned;		\
158 	int __ret_warn_once = !!(condition);			\
159 								\
160 	if (unlikely(__ret_warn_once))				\
161 		if (WARN_TAINT(!__warned, taint, format))	\
162 			__warned = true;			\
163 	unlikely(__ret_warn_once);				\
164 })
165 
166 /*
167  * WARN_ON_SMP() is for cases that the warning is either
168  * meaningless for !SMP or may even cause failures.
169  * This is usually used for cases that we have
170  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
171  * returns 0 for uniprocessor settings.
172  * It can also be used with values that are only defined
173  * on SMP:
174  *
175  * struct foo {
176  *  [...]
177  * #ifdef CONFIG_SMP
178  *	int bar;
179  * #endif
180  * };
181  *
182  * void func(struct foo *zoot)
183  * {
184  *	WARN_ON_SMP(!zoot->bar);
185  *
186  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
187  * and should be a nop and return false for uniprocessor.
188  *
189  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
190  * and x is true.
191  */
192 #ifdef CONFIG_SMP
193 # define WARN_ON_SMP(x)			WARN_ON(x)
194 #else
195 /*
196  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
197  * a stand alone line statement or as a condition in an if ()
198  * statement.
199  * A simple "0" would cause gcc to give a "statement has no effect"
200  * warning.
201  */
202 # define WARN_ON_SMP(x)			({0;})
203 #endif
204 
205 #endif
206