include/asm-generic/bug.h

   1 #ifndef _ASM_GENERIC_BUG_H
   2 #define _ASM_GENERIC_BUG_H
   3
   4 #include <linux/compiler.h>
   5 #include <linux/kernel.h>
   6
   7 #ifdef CONFIG_BUG
   8
   9 #ifdef CONFIG_GENERIC_BUG
  10 #ifndef __ASSEMBLY__
  11 struct bug_entry {
  12 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  13         unsigned long   bug_addr;
  14 #else
  15         signed int      bug_addr_disp;
  16 #endif
  17 #ifdef CONFIG_DEBUG_BUGVERBOSE
  18 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  19         const char      *file;
  20 #else
  21         signed int      file_disp;
  22 #endif
  23         unsigned short  line;
  24 #endif
  25         unsigned short  flags;
  26 };
  27 #endif          /* __ASSEMBLY__ */
  28
  29 #define BUGFLAG_WARNING         (1 << 0)
  30 #define BUGFLAG_TAINT(taint)    (BUGFLAG_WARNING | ((taint) << 8))
  31 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  32
  33 #endif  /* CONFIG_GENERIC_BUG */
  34
  35 /*
  36  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  37  * example might be detecting data structure corruption in the middle
  38  * of an operation that can't be backed out of.  If the (sub)system
  39  * can somehow continue operating, perhaps with reduced functionality,
  40  * it's probably not BUG-worthy.
  41  *
  42  * If you're tempted to BUG(), think again:  is completely giving up
  43  * really the *only* solution?  There are usually better options, where
  44  * users don't need to reboot ASAP and can mostly shut down cleanly.
  45  */
  46 #ifndef HAVE_ARCH_BUG
  47 #define BUG() do { \
  48         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  49         panic("BUG!"); \
  50 } while (0)
  51 #endif
  52
  53 #ifndef HAVE_ARCH_BUG_ON
  54 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
  55 #endif
  56
  57 /*
  58  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  59  * significant issues that need prompt attention if they should ever
  60  * appear at runtime.  Use the versions with printk format strings
  61  * to provide better diagnostics.
  62  */
  63 #ifndef __WARN_TAINT
  64 #ifndef __ASSEMBLY__
  65 extern __printf(3, 4)
  66 void warn_slowpath_fmt(const char *file, const int line,
  67                        const char *fmt, ...);
  68 extern __printf(4, 5)
  69 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  70                              const char *fmt, ...);
  71 extern void warn_slowpath_null(const char *file, const int line);
  72 #define WANT_WARN_ON_SLOWPATH
  73 #endif
  74 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
  75 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
  76 #define __WARN_printf_taint(taint, arg...)                              \
  77         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
  78 #else
  79 #define __WARN()                __WARN_TAINT(TAINT_WARN)
  80 #define __WARN_printf(arg...)   do { printk(arg); __WARN(); } while (0)
  81 #define __WARN_printf_taint(taint, arg...)                              \
  82         do { printk(arg); __WARN_TAINT(taint); } while (0)
  83 #endif
  84
  85 #ifndef WARN_ON
  86 #define WARN_ON(condition) ({                                           \
  87         int __ret_warn_on = !!(condition);                              \
  88         if (unlikely(__ret_warn_on))                                    \
  89                 __WARN();                                               \
  90         unlikely(__ret_warn_on);                                        \
  91 })
  92 #endif
  93
  94 #ifndef WARN
  95 #define WARN(condition, format...) ({                                           \
  96         int __ret_warn_on = !!(condition);                              \
  97         if (unlikely(__ret_warn_on))                                    \
  98                 __WARN_printf(format);                                  \
  99         unlikely(__ret_warn_on);                                        \
 100 })
 101 #endif
 102
 103 #define WARN_TAINT(condition, taint, format...) ({                      \
 104         int __ret_warn_on = !!(condition);                              \
 105         if (unlikely(__ret_warn_on))                                    \
 106                 __WARN_printf_taint(taint, format);                     \
 107         unlikely(__ret_warn_on);                                        \
 108 })
 109
 110 #else /* !CONFIG_BUG */
 111 #ifndef HAVE_ARCH_BUG
 112 #define BUG() do {} while(0)
 113 #endif
 114
 115 #ifndef HAVE_ARCH_BUG_ON
 116 #define BUG_ON(condition) do { if (condition) ; } while(0)
 117 #endif
 118
 119 #ifndef HAVE_ARCH_WARN_ON
 120 #define WARN_ON(condition) ({                                           \
 121         int __ret_warn_on = !!(condition);                              \
 122         unlikely(__ret_warn_on);                                        \
 123 })
 124 #endif
 125
 126 #ifndef WARN
 127 #define WARN(condition, format...) ({                                   \
 128         int __ret_warn_on = !!(condition);                              \
 129         unlikely(__ret_warn_on);                                        \
 130 })
 131 #endif
 132
 133 #define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
 134
 135 #endif
 136
 137 #define WARN_ON_ONCE(condition) ({                              \
 138         static bool __section(.data.unlikely) __warned;         \
 139         int __ret_warn_once = !!(condition);                    \
 140                                                                 \
 141         if (unlikely(__ret_warn_once))                          \
 142                 if (WARN_ON(!__warned))                         \
 143                         __warned = true;                        \
 144         unlikely(__ret_warn_once);                              \
 145 })
 146
 147 #define WARN_ONCE(condition, format...) ({                      \
 148         static bool __section(.data.unlikely) __warned;         \
 149         int __ret_warn_once = !!(condition);                    \
 150                                                                 \
 151         if (unlikely(__ret_warn_once))                          \
 152                 if (WARN(!__warned, format))                    \
 153                         __warned = true;                        \
 154         unlikely(__ret_warn_once);                              \
 155 })
 156
 157 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 158         static bool __section(.data.unlikely) __warned;         \
 159         int __ret_warn_once = !!(condition);                    \
 160                                                                 \
 161         if (unlikely(__ret_warn_once))                          \
 162                 if (WARN_TAINT(!__warned, taint, format))       \
 163                         __warned = true;                        \
 164         unlikely(__ret_warn_once);                              \
 165 })
 166
 167 /*
 168  * WARN_ON_SMP() is for cases that the warning is either
 169  * meaningless for !SMP or may even cause failures.
 170  * This is usually used for cases that we have
 171  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 172  * returns 0 for uniprocessor settings.
 173  * It can also be used with values that are only defined
 174  * on SMP:
 175  *
 176  * struct foo {
 177  *  [...]
 178  * #ifdef CONFIG_SMP
 179  *      int bar;
 180  * #endif
 181  * };
 182  *
 183  * void func(struct foo *zoot)
 184  * {
 185  *      WARN_ON_SMP(!zoot->bar);
 186  *
 187  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 188  * and should be a nop and return false for uniprocessor.
 189  *
 190  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 191  * and x is true.
 192  */
 193 #ifdef CONFIG_SMP
 194 # define WARN_ON_SMP(x)                 WARN_ON(x)
 195 #else
 196 /*
 197  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 198  * a stand alone line statement or as a condition in an if ()
 199  * statement.
 200  * A simple "0" would cause gcc to give a "statement has no effect"
 201  * warning.
 202  */
 203 # define WARN_ON_SMP(x)                 ({0;})
 204 #endif
 205
 206 #endif