include/asm-generic/bug.h

   1 #ifndef _ASM_GENERIC_BUG_H
   2 #define _ASM_GENERIC_BUG_H
   3
   4 #include <linux/compiler.h>
   5
   6 #ifdef CONFIG_BUG
   7
   8 #ifdef CONFIG_GENERIC_BUG
   9 #ifndef __ASSEMBLY__
  10 struct bug_entry {
  11 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  12         unsigned long   bug_addr;
  13 #else
  14         signed int      bug_addr_disp;
  15 #endif
  16 #ifdef CONFIG_DEBUG_BUGVERBOSE
  17 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  18         const char      *file;
  19 #else
  20         signed int      file_disp;
  21 #endif
  22         unsigned short  line;
  23 #endif
  24         unsigned short  flags;
  25 };
  26 #endif          /* __ASSEMBLY__ */
  27
  28 #define BUGFLAG_WARNING         (1 << 0)
  29 #define BUGFLAG_TAINT(taint)    (BUGFLAG_WARNING | ((taint) << 8))
  30 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  31
  32 #endif  /* CONFIG_GENERIC_BUG */
  33
  34 /*
  35  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  36  * example might be detecting data structure corruption in the middle
  37  * of an operation that can't be backed out of.  If the (sub)system
  38  * can somehow continue operating, perhaps with reduced functionality,
  39  * it's probably not BUG-worthy.
  40  *
  41  * If you're tempted to BUG(), think again:  is completely giving up
  42  * really the *only* solution?  There are usually better options, where
  43  * users don't need to reboot ASAP and can mostly shut down cleanly.
  44  */
  45 #ifndef HAVE_ARCH_BUG
  46 #define BUG() do { \
  47         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  48         panic("BUG!"); \
  49 } while (0)
  50 #endif
  51
  52 #ifndef HAVE_ARCH_BUG_ON
  53 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
  54 #endif
  55
  56 /*
  57  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  58  * significant issues that need prompt attention if they should ever
  59  * appear at runtime.  Use the versions with printk format strings
  60  * to provide better diagnostics.
  61  */
  62 #ifndef __WARN_TAINT
  63 #ifndef __ASSEMBLY__
  64 extern __printf(3, 4)
  65 void warn_slowpath_fmt(const char *file, const int line,
  66                        const char *fmt, ...);
  67 extern __printf(4, 5)
  68 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  69                              const char *fmt, ...);
  70 extern void warn_slowpath_null(const char *file, const int line);
  71 #define WANT_WARN_ON_SLOWPATH
  72 #endif
  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 #ifndef WARN_ON
  85 #define WARN_ON(condition) ({                                           \
  86         int __ret_warn_on = !!(condition);                              \
  87         if (unlikely(__ret_warn_on))                                    \
  88                 __WARN();                                               \
  89         unlikely(__ret_warn_on);                                        \
  90 })
  91 #endif
  92
  93 #ifndef WARN
  94 #define WARN(condition, format...) ({                                           \
  95         int __ret_warn_on = !!(condition);                              \
  96         if (unlikely(__ret_warn_on))                                    \
  97                 __WARN_printf(format);                                  \
  98         unlikely(__ret_warn_on);                                        \
  99 })
 100 #endif
 101
 102 #define WARN_TAINT(condition, taint, format...) ({                      \
 103         int __ret_warn_on = !!(condition);                              \
 104         if (unlikely(__ret_warn_on))                                    \
 105                 __WARN_printf_taint(taint, format);                     \
 106         unlikely(__ret_warn_on);                                        \
 107 })
 108
 109 #else /* !CONFIG_BUG */
 110 #ifndef HAVE_ARCH_BUG
 111 #define BUG() do {} while(0)
 112 #endif
 113
 114 #ifndef HAVE_ARCH_BUG_ON
 115 #define BUG_ON(condition) do { if (condition) ; } while(0)
 116 #endif
 117
 118 #ifndef HAVE_ARCH_WARN_ON
 119 #define WARN_ON(condition) ({                                           \
 120         int __ret_warn_on = !!(condition);                              \
 121         unlikely(__ret_warn_on);                                        \
 122 })
 123 #endif
 124
 125 #ifndef WARN
 126 #define WARN(condition, format...) ({                                   \
 127         int __ret_warn_on = !!(condition);                              \
 128         unlikely(__ret_warn_on);                                        \
 129 })
 130 #endif
 131
 132 #define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
 133
 134 #endif
 135
 136 #define WARN_ON_ONCE(condition) ({                              \
 137         static bool __warned;                                   \
 138         int __ret_warn_once = !!(condition);                    \
 139                                                                 \
 140         if (unlikely(__ret_warn_once))                          \
 141                 if (WARN_ON(!__warned))                         \
 142                         __warned = true;                        \
 143         unlikely(__ret_warn_once);                              \
 144 })
 145
 146 #define WARN_ONCE(condition, format...) ({                      \
 147         static bool __warned;                                   \
 148         int __ret_warn_once = !!(condition);                    \
 149                                                                 \
 150         if (unlikely(__ret_warn_once))                          \
 151                 if (WARN(!__warned, format))                    \
 152                         __warned = true;                        \
 153         unlikely(__ret_warn_once);                              \
 154 })
 155
 156 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 157         static bool __warned;                                   \
 158         int __ret_warn_once = !!(condition);                    \
 159                                                                 \
 160         if (unlikely(__ret_warn_once))                          \
 161                 if (WARN_TAINT(!__warned, taint, format))       \
 162                         __warned = true;                        \
 163         unlikely(__ret_warn_once);                              \
 164 })
 165
 166 /*
 167  * WARN_ON_SMP() is for cases that the warning is either
 168  * meaningless for !SMP or may even cause failures.
 169  * This is usually used for cases that we have
 170  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 171  * returns 0 for uniprocessor settings.
 172  * It can also be used with values that are only defined
 173  * on SMP:
 174  *
 175  * struct foo {
 176  *  [...]
 177  * #ifdef CONFIG_SMP
 178  *      int bar;
 179  * #endif
 180  * };
 181  *
 182  * void func(struct foo *zoot)
 183  * {
 184  *      WARN_ON_SMP(!zoot->bar);
 185  *
 186  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 187  * and should be a nop and return false for uniprocessor.
 188  *
 189  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 190  * and x is true.
 191  */
 192 #ifdef CONFIG_SMP
 193 # define WARN_ON_SMP(x)                 WARN_ON(x)
 194 #else
 195 /*
 196  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 197  * a stand alone line statement or as a condition in an if ()
 198  * statement.
 199  * A simple "0" would cause gcc to give a "statement has no effect"
 200  * warning.
 201  */
 202 # define WARN_ON_SMP(x)                 ({0;})
 203 #endif
 204
 205 #endif