xref: /linux/include/asm-generic/bug.h (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
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 /* used internally by panic.c */
85 struct warn_args;
86 
87 void __warn(const char *file, int line, void *caller, unsigned taint,
88 	    struct pt_regs *regs, struct warn_args *args);
89 
90 #ifndef WARN_ON
91 #define WARN_ON(condition) ({						\
92 	int __ret_warn_on = !!(condition);				\
93 	if (unlikely(__ret_warn_on))					\
94 		__WARN();						\
95 	unlikely(__ret_warn_on);					\
96 })
97 #endif
98 
99 #ifndef WARN
100 #define WARN(condition, format...) ({						\
101 	int __ret_warn_on = !!(condition);				\
102 	if (unlikely(__ret_warn_on))					\
103 		__WARN_printf(format);					\
104 	unlikely(__ret_warn_on);					\
105 })
106 #endif
107 
108 #define WARN_TAINT(condition, taint, format...) ({			\
109 	int __ret_warn_on = !!(condition);				\
110 	if (unlikely(__ret_warn_on))					\
111 		__WARN_printf_taint(taint, format);			\
112 	unlikely(__ret_warn_on);					\
113 })
114 
115 #define WARN_ON_ONCE(condition)	({				\
116 	static bool __section(.data.unlikely) __warned;		\
117 	int __ret_warn_once = !!(condition);			\
118 								\
119 	if (unlikely(__ret_warn_once && !__warned)) {		\
120 		__warned = true;				\
121 		WARN_ON(1);					\
122 	}							\
123 	unlikely(__ret_warn_once);				\
124 })
125 
126 #define WARN_ONCE(condition, format...)	({			\
127 	static bool __section(.data.unlikely) __warned;		\
128 	int __ret_warn_once = !!(condition);			\
129 								\
130 	if (unlikely(__ret_warn_once && !__warned)) {		\
131 		__warned = true;				\
132 		WARN(1, format);				\
133 	}							\
134 	unlikely(__ret_warn_once);				\
135 })
136 
137 #define WARN_TAINT_ONCE(condition, taint, format...)	({	\
138 	static bool __section(.data.unlikely) __warned;		\
139 	int __ret_warn_once = !!(condition);			\
140 								\
141 	if (unlikely(__ret_warn_once && !__warned)) {		\
142 		__warned = true;				\
143 		WARN_TAINT(1, taint, format);			\
144 	}							\
145 	unlikely(__ret_warn_once);				\
146 })
147 
148 #else /* !CONFIG_BUG */
149 #ifndef HAVE_ARCH_BUG
150 #define BUG() do {} while (1)
151 #endif
152 
153 #ifndef HAVE_ARCH_BUG_ON
154 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
155 #endif
156 
157 #ifndef HAVE_ARCH_WARN_ON
158 #define WARN_ON(condition) ({						\
159 	int __ret_warn_on = !!(condition);				\
160 	unlikely(__ret_warn_on);					\
161 })
162 #endif
163 
164 #ifndef WARN
165 #define WARN(condition, format...) ({					\
166 	int __ret_warn_on = !!(condition);				\
167 	no_printk(format);						\
168 	unlikely(__ret_warn_on);					\
169 })
170 #endif
171 
172 #define WARN_ON_ONCE(condition) WARN_ON(condition)
173 #define WARN_ONCE(condition, format...) WARN(condition, format)
174 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
175 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
176 
177 #endif
178 
179 /*
180  * WARN_ON_SMP() is for cases that the warning is either
181  * meaningless for !SMP or may even cause failures.
182  * This is usually used for cases that we have
183  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
184  * returns 0 for uniprocessor settings.
185  * It can also be used with values that are only defined
186  * on SMP:
187  *
188  * struct foo {
189  *  [...]
190  * #ifdef CONFIG_SMP
191  *	int bar;
192  * #endif
193  * };
194  *
195  * void func(struct foo *zoot)
196  * {
197  *	WARN_ON_SMP(!zoot->bar);
198  *
199  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
200  * and should be a nop and return false for uniprocessor.
201  *
202  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
203  * and x is true.
204  */
205 #ifdef CONFIG_SMP
206 # define WARN_ON_SMP(x)			WARN_ON(x)
207 #else
208 /*
209  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
210  * a stand alone line statement or as a condition in an if ()
211  * statement.
212  * A simple "0" would cause gcc to give a "statement has no effect"
213  * warning.
214  */
215 # define WARN_ON_SMP(x)			({0;})
216 #endif
217 
218 #endif /* __ASSEMBLY__ */
219 
220 #endif
221