xref: /linux/include/asm-generic/bug.h (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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_ONCE		(1 << 1)
9 #define BUGFLAG_DONE		(1 << 2)
10 #define BUGFLAG_TAINT(taint)	((taint) << 8)
11 #define BUG_GET_TAINT(bug)	((bug)->flags >> 8)
12 #endif
13 
14 #ifndef __ASSEMBLY__
15 #include <linux/kernel.h>
16 
17 #ifdef CONFIG_BUG
18 
19 #ifdef CONFIG_GENERIC_BUG
20 struct bug_entry {
21 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
22 	unsigned long	bug_addr;
23 #else
24 	signed int	bug_addr_disp;
25 #endif
26 #ifdef CONFIG_DEBUG_BUGVERBOSE
27 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
28 	const char	*file;
29 #else
30 	signed int	file_disp;
31 #endif
32 	unsigned short	line;
33 #endif
34 	unsigned short	flags;
35 };
36 #endif	/* CONFIG_GENERIC_BUG */
37 
38 /*
39  * Don't use BUG() or BUG_ON() unless there's really no way out; one
40  * example might be detecting data structure corruption in the middle
41  * of an operation that can't be backed out of.  If the (sub)system
42  * can somehow continue operating, perhaps with reduced functionality,
43  * it's probably not BUG-worthy.
44  *
45  * If you're tempted to BUG(), think again:  is completely giving up
46  * really the *only* solution?  There are usually better options, where
47  * users don't need to reboot ASAP and can mostly shut down cleanly.
48  */
49 #ifndef HAVE_ARCH_BUG
50 #define BUG() do { \
51 	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
52 	panic("BUG!"); \
53 } while (0)
54 #endif
55 
56 #ifndef HAVE_ARCH_BUG_ON
57 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
58 #endif
59 
60 #ifdef __WARN_FLAGS
61 #define __WARN_TAINT(taint)		__WARN_FLAGS(BUGFLAG_TAINT(taint))
62 #define __WARN_ONCE_TAINT(taint)	__WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
63 
64 #define WARN_ON_ONCE(condition) ({				\
65 	int __ret_warn_on = !!(condition);			\
66 	if (unlikely(__ret_warn_on))				\
67 		__WARN_ONCE_TAINT(TAINT_WARN);			\
68 	unlikely(__ret_warn_on);				\
69 })
70 #endif
71 
72 /*
73  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
74  * significant issues that need prompt attention if they should ever
75  * appear at runtime.  Use the versions with printk format strings
76  * to provide better diagnostics.
77  */
78 #ifndef __WARN_TAINT
79 extern __printf(3, 4)
80 void warn_slowpath_fmt(const char *file, const int line,
81 		       const char *fmt, ...);
82 extern __printf(4, 5)
83 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
84 			     const char *fmt, ...);
85 extern void warn_slowpath_null(const char *file, const int line);
86 #define WANT_WARN_ON_SLOWPATH
87 #define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
88 #define __WARN_printf(arg...)	warn_slowpath_fmt(__FILE__, __LINE__, arg)
89 #define __WARN_printf_taint(taint, arg...)				\
90 	warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
91 #else
92 #define __WARN()		__WARN_TAINT(TAINT_WARN)
93 #define __WARN_printf(arg...)	do { printk(arg); __WARN(); } while (0)
94 #define __WARN_printf_taint(taint, arg...)				\
95 	do { printk(arg); __WARN_TAINT(taint); } while (0)
96 #endif
97 
98 /* used internally by panic.c */
99 struct warn_args;
100 
101 void __warn(const char *file, int line, void *caller, unsigned taint,
102 	    struct pt_regs *regs, struct warn_args *args);
103 
104 #ifndef WARN_ON
105 #define WARN_ON(condition) ({						\
106 	int __ret_warn_on = !!(condition);				\
107 	if (unlikely(__ret_warn_on))					\
108 		__WARN();						\
109 	unlikely(__ret_warn_on);					\
110 })
111 #endif
112 
113 #ifndef WARN
114 #define WARN(condition, format...) ({					\
115 	int __ret_warn_on = !!(condition);				\
116 	if (unlikely(__ret_warn_on))					\
117 		__WARN_printf(format);					\
118 	unlikely(__ret_warn_on);					\
119 })
120 #endif
121 
122 #define WARN_TAINT(condition, taint, format...) ({			\
123 	int __ret_warn_on = !!(condition);				\
124 	if (unlikely(__ret_warn_on))					\
125 		__WARN_printf_taint(taint, format);			\
126 	unlikely(__ret_warn_on);					\
127 })
128 
129 #ifndef WARN_ON_ONCE
130 #define WARN_ON_ONCE(condition)	({				\
131 	static bool __section(.data.unlikely) __warned;		\
132 	int __ret_warn_once = !!(condition);			\
133 								\
134 	if (unlikely(__ret_warn_once && !__warned)) {		\
135 		__warned = true;				\
136 		WARN_ON(1);					\
137 	}							\
138 	unlikely(__ret_warn_once);				\
139 })
140 #endif
141 
142 #define WARN_ONCE(condition, format...)	({			\
143 	static bool __section(.data.unlikely) __warned;		\
144 	int __ret_warn_once = !!(condition);			\
145 								\
146 	if (unlikely(__ret_warn_once && !__warned)) {		\
147 		__warned = true;				\
148 		WARN(1, format);				\
149 	}							\
150 	unlikely(__ret_warn_once);				\
151 })
152 
153 #define WARN_TAINT_ONCE(condition, taint, format...)	({	\
154 	static bool __section(.data.unlikely) __warned;		\
155 	int __ret_warn_once = !!(condition);			\
156 								\
157 	if (unlikely(__ret_warn_once && !__warned)) {		\
158 		__warned = true;				\
159 		WARN_TAINT(1, taint, format);			\
160 	}							\
161 	unlikely(__ret_warn_once);				\
162 })
163 
164 #else /* !CONFIG_BUG */
165 #ifndef HAVE_ARCH_BUG
166 #define BUG() do {} while (1)
167 #endif
168 
169 #ifndef HAVE_ARCH_BUG_ON
170 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
171 #endif
172 
173 #ifndef HAVE_ARCH_WARN_ON
174 #define WARN_ON(condition) ({						\
175 	int __ret_warn_on = !!(condition);				\
176 	unlikely(__ret_warn_on);					\
177 })
178 #endif
179 
180 #ifndef WARN
181 #define WARN(condition, format...) ({					\
182 	int __ret_warn_on = !!(condition);				\
183 	no_printk(format);						\
184 	unlikely(__ret_warn_on);					\
185 })
186 #endif
187 
188 #define WARN_ON_ONCE(condition) WARN_ON(condition)
189 #define WARN_ONCE(condition, format...) WARN(condition, format)
190 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
191 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
192 
193 #endif
194 
195 /*
196  * WARN_ON_SMP() is for cases that the warning is either
197  * meaningless for !SMP or may even cause failures.
198  * This is usually used for cases that we have
199  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
200  * returns 0 for uniprocessor settings.
201  * It can also be used with values that are only defined
202  * on SMP:
203  *
204  * struct foo {
205  *  [...]
206  * #ifdef CONFIG_SMP
207  *	int bar;
208  * #endif
209  * };
210  *
211  * void func(struct foo *zoot)
212  * {
213  *	WARN_ON_SMP(!zoot->bar);
214  *
215  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
216  * and should be a nop and return false for uniprocessor.
217  *
218  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
219  * and x is true.
220  */
221 #ifdef CONFIG_SMP
222 # define WARN_ON_SMP(x)			WARN_ON(x)
223 #else
224 /*
225  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
226  * a stand alone line statement or as a condition in an if ()
227  * statement.
228  * A simple "0" would cause gcc to give a "statement has no effect"
229  * warning.
230  */
231 # define WARN_ON_SMP(x)			({0;})
232 #endif
233 
234 #endif /* __ASSEMBLY__ */
235 
236 #endif
237