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 void warn_slowpath_fmt(const char *file, const int line,
  65                 const char *fmt, ...) __attribute__((format(printf, 3, 4)));
  66 extern void warn_slowpath_fmt_taint(const char *file, const int line,
  67                                     unsigned taint, const char *fmt, ...)
  68         __attribute__((format(printf, 4, 5)));
  69 extern void warn_slowpath_null(const char *file, const int line);
  70 #define WANT_WARN_ON_SLOWPATH
  71 #endif
  72 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
  73 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
  74 #define __WARN_printf_taint(taint, arg...)                              \
  75         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
  76 #else
  77 #define __WARN()                __WARN_TAINT(TAINT_WARN)
  78 #define __WARN_printf(arg...)   do { printk(arg); __WARN(); } while (0)
  79 #define __WARN_printf_taint(taint, arg...)                              \
  80         do { printk(arg); __WARN_TAINT(taint); } while (0)
  81 #endif
  82
  83 #ifndef WARN_ON
  84 #define WARN_ON(condition) ({                                           \
  85         int __ret_warn_on = !!(condition);                              \
  86         if (unlikely(__ret_warn_on))                                    \
  87                 __WARN();                                               \
  88         unlikely(__ret_warn_on);                                        \
  89 })
  90 #endif
  91
  92 #ifndef WARN
  93 #define WARN(condition, format...) ({                                           \
  94         int __ret_warn_on = !!(condition);                              \
  95         if (unlikely(__ret_warn_on))                                    \
  96                 __WARN_printf(format);                                  \
  97         unlikely(__ret_warn_on);                                        \
  98 })
  99 #endif
 100
 101 #define WARN_TAINT(condition, taint, format...) ({                      \
 102         int __ret_warn_on = !!(condition);                              \
 103         if (unlikely(__ret_warn_on))                                    \
 104                 __WARN_printf_taint(taint, format);                     \
 105         unlikely(__ret_warn_on);                                        \
 106 })
 107
 108 #else /* !CONFIG_BUG */
 109 #ifndef HAVE_ARCH_BUG
 110 #define BUG() do {} while(0)
 111 #endif
 112
 113 #ifndef HAVE_ARCH_BUG_ON
 114 #define BUG_ON(condition) do { if (condition) ; } while(0)
 115 #endif
 116
 117 #ifndef HAVE_ARCH_WARN_ON
 118 #define WARN_ON(condition) ({                                           \
 119         int __ret_warn_on = !!(condition);                              \
 120         unlikely(__ret_warn_on);                                        \
 121 })
 122 #endif
 123
 124 #ifndef WARN
 125 #define WARN(condition, format...) ({                                   \
 126         int __ret_warn_on = !!(condition);                              \
 127         unlikely(__ret_warn_on);                                        \
 128 })
 129 #endif
 130
 131 #define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
 132
 133 #endif
 134
 135 #define WARN_ON_ONCE(condition) ({                              \
 136         static bool __warned;                                   \
 137         int __ret_warn_once = !!(condition);                    \
 138                                                                 \
 139         if (unlikely(__ret_warn_once))                          \
 140                 if (WARN_ON(!__warned))                         \
 141                         __warned = true;                        \
 142         unlikely(__ret_warn_once);                              \
 143 })
 144
 145 #define WARN_ONCE(condition, format...) ({                      \
 146         static bool __warned;                                   \
 147         int __ret_warn_once = !!(condition);                    \
 148                                                                 \
 149         if (unlikely(__ret_warn_once))                          \
 150                 if (WARN(!__warned, format))                    \
 151                         __warned = true;                        \
 152         unlikely(__ret_warn_once);                              \
 153 })
 154
 155 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 156         static bool __warned;                                   \
 157         int __ret_warn_once = !!(condition);                    \
 158                                                                 \
 159         if (unlikely(__ret_warn_once))                          \
 160                 if (WARN_TAINT(!__warned, taint, format))       \
 161                         __warned = true;                        \
 162         unlikely(__ret_warn_once);                              \
 163 })
 164
 165 /*
 166  * WARN_ON_SMP() is for cases that the warning is either
 167  * meaningless for !SMP or may even cause failures.
 168  * This is usually used for cases that we have
 169  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 170  * returns 0 for uniprocessor settings.
 171  * It can also be used with values that are only defined
 172  * on SMP:
 173  *
 174  * struct foo {
 175  *  [...]
 176  * #ifdef CONFIG_SMP
 177  *      int bar;
 178  * #endif
 179  * };
 180  *
 181  * void func(struct foo *zoot)
 182  * {
 183  *      WARN_ON_SMP(!zoot->bar);
 184  *
 185  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 186  * and should be a nop and return false for uniprocessor.
 187  *
 188  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 189  * and x is true.
 190  */
 191 #ifdef CONFIG_SMP
 192 # define WARN_ON_SMP(x)                 WARN_ON(x)
 193 #else
 194 /*
 195  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 196  * a stand alone line statement or as a condition in an if ()
 197  * statement.
 198  * A simple "0" would cause gcc to give a "statement has no effect"
 199  * warning.
 200  */
 201 # define WARN_ON_SMP(x)                 ({0;})
 202 #endif
 203
 204 #endif