1 #ifndef _LINUX_BUG_H
2 #define _LINUX_BUG_H
3
4 #include <asm/bug.h>
5
6 enum bug_trap_type {
7 BUG_TRAP_TYPE_NONE = 0,
8 BUG_TRAP_TYPE_WARN = 1,
9 BUG_TRAP_TYPE_BUG = 2,
10 };
11
12 struct pt_regs;
13
14 #ifdef __CHECKER__
15 #define BUILD_BUG_ON_NOT_POWER_OF_2(n)
16 #define BUILD_BUG_ON_ZERO(e) (0)
17 #define BUILD_BUG_ON_NULL(e) ((void*)0)
18 #define BUILD_BUG_ON(condition)
19 #define BUILD_BUG() (0)
20 #else /* __CHECKER__ */
21
22 /* Force a compilation error if a constant expression is not a power of 2 */
23 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
24 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
25
26 /* Force a compilation error if condition is true, but also produce a
27 result (of value 0 and type size_t), so the expression can be used
28 e.g. in a structure initializer (or where-ever else comma expressions
29 aren't permitted). */
30 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
31 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
32
33 /**
34 * BUILD_BUG_ON - break compile if a condition is true.
35 * @condition: the condition which the compiler should know is false.
36 *
37 * If you have some code which relies on certain constants being equal, or
38 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
39 * detect if someone changes it.
40 *
41 * The implementation uses gcc's reluctance to create a negative array, but
42 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
43 * to inline functions). So as a fallback we use the optimizer; if it can't
44 * prove the condition is false, it will cause a link error on the undefined
45 * "__build_bug_on_failed". This error message can be harder to track down
46 * though, hence the two different methods.
47 */
48 #ifndef __OPTIMIZE__
49 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
50 #else
51 extern int __build_bug_on_failed;
52 #define BUILD_BUG_ON(condition) \
53 do { \
54 ((void)sizeof(char[1 - 2*!!(condition)])); \
55 if (condition) __build_bug_on_failed = 1; \
56 } while(0)
57 #endif
58
59 /**
60 * BUILD_BUG - break compile if used.
61 *
62 * If you have some code that you expect the compiler to eliminate at
63 * build time, you should use BUILD_BUG to detect if it is
64 * unexpectedly used.
65 */
66 #define BUILD_BUG() \
67 do { \
68 extern void __build_bug_failed(void) \
69 __linktime_error("BUILD_BUG failed"); \
70 __build_bug_failed(); \
71 } while (0)
72
73 #endif /* __CHECKER__ */
74
75 #ifdef CONFIG_GENERIC_BUG
76 #include <asm-generic/bug.h>
77
is_warning_bug(const struct bug_entry * bug)78 static inline int is_warning_bug(const struct bug_entry *bug)
79 {
80 return bug->flags & BUGFLAG_WARNING;
81 }
82
83 const struct bug_entry *find_bug(unsigned long bugaddr);
84
85 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
86
87 /* These are defined by the architecture */
88 int is_valid_bugaddr(unsigned long addr);
89
90 #else /* !CONFIG_GENERIC_BUG */
91
report_bug(unsigned long bug_addr,struct pt_regs * regs)92 static inline enum bug_trap_type report_bug(unsigned long bug_addr,
93 struct pt_regs *regs)
94 {
95 return BUG_TRAP_TYPE_BUG;
96 }
97
98 #endif /* CONFIG_GENERIC_BUG */
99 #endif /* _LINUX_BUG_H */
100