blob: 6f3da08f4eba6ea5fd8014839c0169f2da74de99 [file] [log] [blame]
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -08001#ifndef _LINUX_BUG_H
2#define _LINUX_BUG_H
3
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -08004#include <asm/bug.h>
Daniel Santosa3ccc492013-02-21 16:41:52 -08005#include <linux/compiler.h>
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -08006
7enum bug_trap_type {
8 BUG_TRAP_TYPE_NONE = 0,
9 BUG_TRAP_TYPE_WARN = 1,
10 BUG_TRAP_TYPE_BUG = 2,
11};
12
Heiko Carstens608e2612007-07-15 23:41:39 -070013struct pt_regs;
14
Paul Gortmaker35edd912011-11-16 23:51:05 -050015#ifdef __CHECKER__
Jakub Kicinski3e9b3112016-08-31 12:46:44 +010016#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
Daniel Santosca623c92013-02-21 16:41:44 -080017#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
Paul Gortmaker35edd912011-11-16 23:51:05 -050018#define BUILD_BUG_ON_ZERO(e) (0)
19#define BUILD_BUG_ON_NULL(e) ((void*)0)
Tushar Beherac5782e92012-11-26 16:29:38 -080020#define BUILD_BUG_ON_INVALID(e) (0)
Daniel Santos9a8ab1c2013-02-21 16:41:55 -080021#define BUILD_BUG_ON_MSG(cond, msg) (0)
Daniel Santosca623c92013-02-21 16:41:44 -080022#define BUILD_BUG_ON(condition) (0)
Paul Gortmaker35edd912011-11-16 23:51:05 -050023#define BUILD_BUG() (0)
Kirill A. Shutemovff20c2e2016-03-01 09:45:14 +053024#define MAYBE_BUILD_BUG_ON(cond) (0)
Paul Gortmaker35edd912011-11-16 23:51:05 -050025#else /* __CHECKER__ */
26
27/* Force a compilation error if a constant expression is not a power of 2 */
Jakub Kicinski3e9b3112016-08-31 12:46:44 +010028#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \
29 BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
Paul Gortmaker35edd912011-11-16 23:51:05 -050030#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
31 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
32
33/* Force a compilation error if condition is true, but also produce a
34 result (of value 0 and type size_t), so the expression can be used
35 e.g. in a structure initializer (or where-ever else comma expressions
36 aren't permitted). */
37#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
38#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
39
Konstantin Khlebnikovbaf05aa2012-05-29 15:06:27 -070040/*
41 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
42 * expression but avoids the generation of any code, even if that expression
43 * has side-effects.
44 */
45#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
46
Paul Gortmaker35edd912011-11-16 23:51:05 -050047/**
Daniel Santos9a8ab1c2013-02-21 16:41:55 -080048 * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
49 * error message.
50 * @condition: the condition which the compiler should know is false.
51 *
52 * See BUILD_BUG_ON for description.
53 */
54#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
55
56/**
Paul Gortmaker35edd912011-11-16 23:51:05 -050057 * BUILD_BUG_ON - break compile if a condition is true.
58 * @condition: the condition which the compiler should know is false.
59 *
60 * If you have some code which relies on certain constants being equal, or
Daniel Santosa3ccc492013-02-21 16:41:52 -080061 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
Paul Gortmaker35edd912011-11-16 23:51:05 -050062 * detect if someone changes it.
63 *
Daniel Santosa3ccc492013-02-21 16:41:52 -080064 * The implementation uses gcc's reluctance to create a negative array, but gcc
65 * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
66 * inline functions). Luckily, in 4.3 they added the "error" function
67 * attribute just for this type of case. Thus, we use a negative sized array
68 * (should always create an error on gcc versions older than 4.4) and then call
69 * an undefined function with the error attribute (should always create an
70 * error on gcc 4.3 and later). If for some reason, neither creates a
71 * compile-time error, we'll still have a link-time error, which is harder to
72 * track down.
Paul Gortmaker35edd912011-11-16 23:51:05 -050073 */
74#ifndef __OPTIMIZE__
75#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
76#else
Daniel Santos9a8ab1c2013-02-21 16:41:55 -080077#define BUILD_BUG_ON(condition) \
78 BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
Paul Gortmaker35edd912011-11-16 23:51:05 -050079#endif
80
81/**
82 * BUILD_BUG - break compile if used.
83 *
84 * If you have some code that you expect the compiler to eliminate at
85 * build time, you should use BUILD_BUG to detect if it is
86 * unexpectedly used.
87 */
Daniel Santos9a8ab1c2013-02-21 16:41:55 -080088#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
Paul Gortmaker35edd912011-11-16 23:51:05 -050089
Kirill A. Shutemovff20c2e2016-03-01 09:45:14 +053090#define MAYBE_BUILD_BUG_ON(cond) \
91 do { \
92 if (__builtin_constant_p((cond))) \
93 BUILD_BUG_ON(cond); \
94 else \
95 BUG_ON(cond); \
96 } while (0)
97
Paul Gortmaker35edd912011-11-16 23:51:05 -050098#endif /* __CHECKER__ */
99
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -0800100#ifdef CONFIG_GENERIC_BUG
101#include <asm-generic/bug.h>
102
103static inline int is_warning_bug(const struct bug_entry *bug)
104{
105 return bug->flags & BUGFLAG_WARNING;
106}
107
108const struct bug_entry *find_bug(unsigned long bugaddr);
109
Heiko Carstens608e2612007-07-15 23:41:39 -0700110enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -0800111
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -0800112/* These are defined by the architecture */
113int is_valid_bugaddr(unsigned long addr);
114
115#else /* !CONFIG_GENERIC_BUG */
116
Heiko Carstens608e2612007-07-15 23:41:39 -0700117static inline enum bug_trap_type report_bug(unsigned long bug_addr,
118 struct pt_regs *regs)
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -0800119{
120 return BUG_TRAP_TYPE_BUG;
121}
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -0800122
123#endif /* CONFIG_GENERIC_BUG */
Syed Rameez Mustafacf9c1e42013-07-15 11:52:09 -0700124
125#ifdef CONFIG_PANIC_ON_DATA_CORRUPTION
126#define PANIC_CORRUPTION 1
127#else
128#define PANIC_CORRUPTION 0
129#endif /* CONFIG_PANIC_ON_DATA_CORRUPTION */
Jeremy Fitzhardinge7664c5a2006-12-08 02:36:19 -0800130#endif /* _LINUX_BUG_H */