1 #ifndef _LINUX_BUG_H 2 #define _LINUX_BUG_H 3 4 #include <asm/bug.h> 5 #include <linux/compiler.h> 6 7 enum bug_trap_type { 8 BUG_TRAP_TYPE_NONE = 0, 9 BUG_TRAP_TYPE_WARN = 1, 10 BUG_TRAP_TYPE_BUG = 2, 11 }; 12 13 struct pt_regs; 14 15 #ifdef __CHECKER__ 16 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) 17 #define BUILD_BUG_ON_ZERO(e) (0) 18 #define BUILD_BUG_ON_NULL(e) ((void*)0) 19 #define BUILD_BUG_ON_INVALID(e) (0) 20 #define BUILD_BUG_ON_MSG(cond, msg) (0) 21 #define BUILD_BUG_ON(condition) (0) 22 #define BUILD_BUG() (0) 23 #define MAYBE_BUILD_BUG_ON(cond) (0) 24 #else /* __CHECKER__ */ 25 26 /* Force a compilation error if a constant expression is not a power of 2 */ 27 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 28 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 29 30 /* Force a compilation error if condition is true, but also produce a 31 result (of value 0 and type size_t), so the expression can be used 32 e.g. in a structure initializer (or where-ever else comma expressions 33 aren't permitted). */ 34 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 35 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 36 37 /* 38 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the 39 * expression but avoids the generation of any code, even if that expression 40 * has side-effects. 41 */ 42 #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) 43 44 /** 45 * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied 46 * error message. 47 * @condition: the condition which the compiler should know is false. 48 * 49 * See BUILD_BUG_ON for description. 50 */ 51 #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) 52 53 /** 54 * BUILD_BUG_ON - break compile if a condition is true. 55 * @condition: the condition which the compiler should know is false. 56 * 57 * If you have some code which relies on certain constants being equal, or 58 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to 59 * detect if someone changes it. 60 * 61 * The implementation uses gcc's reluctance to create a negative array, but gcc 62 * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to 63 * inline functions). Luckily, in 4.3 they added the "error" function 64 * attribute just for this type of case. Thus, we use a negative sized array 65 * (should always create an error on gcc versions older than 4.4) and then call 66 * an undefined function with the error attribute (should always create an 67 * error on gcc 4.3 and later). If for some reason, neither creates a 68 * compile-time error, we'll still have a link-time error, which is harder to 69 * track down. 70 */ 71 #ifndef __OPTIMIZE__ 72 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 73 #else 74 #define BUILD_BUG_ON(condition) \ 75 BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) 76 #endif 77 78 /** 79 * BUILD_BUG - break compile if used. 80 * 81 * If you have some code that you expect the compiler to eliminate at 82 * build time, you should use BUILD_BUG to detect if it is 83 * unexpectedly used. 84 */ 85 #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") 86 87 #define MAYBE_BUILD_BUG_ON(cond) \ 88 do { \ 89 if (__builtin_constant_p((cond))) \ 90 BUILD_BUG_ON(cond); \ 91 else \ 92 BUG_ON(cond); \ 93 } while (0) 94 95 #endif /* __CHECKER__ */ 96 97 #ifdef CONFIG_GENERIC_BUG 98 #include <asm-generic/bug.h> 99 100 static inline int is_warning_bug(const struct bug_entry *bug) 101 { 102 return bug->flags & BUGFLAG_WARNING; 103 } 104 105 const struct bug_entry *find_bug(unsigned long bugaddr); 106 107 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); 108 109 /* These are defined by the architecture */ 110 int is_valid_bugaddr(unsigned long addr); 111 112 #else /* !CONFIG_GENERIC_BUG */ 113 114 static inline enum bug_trap_type report_bug(unsigned long bug_addr, 115 struct pt_regs *regs) 116 { 117 return BUG_TRAP_TYPE_BUG; 118 } 119 120 #endif /* CONFIG_GENERIC_BUG */ 121 #endif /* _LINUX_BUG_H */ 122