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_GENERIC_BUG
   7 #define BUGFLAG_WARNING         (1 << 0)
   8 #define BUGFLAG_TAINT(taint)    (BUGFLAG_WARNING | ((taint) << 8))
   9 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  10 #endif
  11
  12 #ifndef __ASSEMBLY__
  13 #include <linux/kernel.h>
  14
  15 #ifdef CONFIG_BUG
  16
  17 #ifdef CONFIG_GENERIC_BUG
  18 struct bug_entry {
  19 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  20         unsigned long   bug_addr;
  21 #else
  22         signed int      bug_addr_disp;
  23 #endif
  24 #ifdef CONFIG_DEBUG_BUGVERBOSE
  25 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  26         const char      *file;
  27 #else
  28         signed int      file_disp;
  29 #endif
  30         unsigned short  line;
  31 #endif
  32         unsigned short  flags;
  33 };
  34 #endif  /* CONFIG_GENERIC_BUG */
  35
  36 /*
  37  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  38  * example might be detecting data structure corruption in the middle
  39  * of an operation that can't be backed out of.  If the (sub)system
  40  * can somehow continue operating, perhaps with reduced functionality,
  41  * it's probably not BUG-worthy.
  42  *
  43  * If you're tempted to BUG(), think again:  is completely giving up
  44  * really the *only* solution?  There are usually better options, where
  45  * users don't need to reboot ASAP and can mostly shut down cleanly.
  46  */
  47 #ifndef HAVE_ARCH_BUG
  48 #define BUG() do { \
  49         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  50         barrier_before_unreachable(); \
  51         panic("BUG!"); \
  52 } while (0)
  53 #endif
  54
  55 #ifndef HAVE_ARCH_BUG_ON
  56 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  57 #endif
  58
  59 /*
  60  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  61  * significant issues that need prompt attention if they should ever
  62  * appear at runtime.  Use the versions with printk format strings
  63  * to provide better diagnostics.
  64  */
  65 #ifndef __WARN_TAINT
  66 extern __printf(3, 4)
  67 void warn_slowpath_fmt(const char *file, const int line,
  68                        const char *fmt, ...);
  69 extern __printf(4, 5)
  70 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  71                              const char *fmt, ...);
  72 extern void warn_slowpath_null(const char *file, const int line);
  73 #define WANT_WARN_ON_SLOWPATH
  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 #define WARN_ON_ONCE(condition) ({                              \
 111         static bool __section(.data.unlikely) __warned;         \
 112         int __ret_warn_once = !!(condition);                    \
 113                                                                 \
 114         if (unlikely(__ret_warn_once))                          \
 115                 if (WARN_ON(!__warned))                         \
 116                         __warned = true;                        \
 117         unlikely(__ret_warn_once);                              \
 118 })
 119
 120 #define WARN_ONCE(condition, format...) ({                      \
 121         static bool __section(.data.unlikely) __warned;         \
 122         int __ret_warn_once = !!(condition);                    \
 123                                                                 \
 124         if (unlikely(__ret_warn_once))                          \
 125                 if (WARN(!__warned, format))                    \
 126                         __warned = true;                        \
 127         unlikely(__ret_warn_once);                              \
 128 })
 129
 130 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 131         static bool __section(.data.unlikely) __warned;         \
 132         int __ret_warn_once = !!(condition);                    \
 133                                                                 \
 134         if (unlikely(__ret_warn_once))                          \
 135                 if (WARN_TAINT(!__warned, taint, format))       \
 136                         __warned = true;                        \
 137         unlikely(__ret_warn_once);                              \
 138 })
 139
 140 #else /* !CONFIG_BUG */
 141 #ifndef HAVE_ARCH_BUG
 142 #define BUG() do {} while (1)
 143 #endif
 144
 145 #ifndef HAVE_ARCH_BUG_ON
 146 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 147 #endif
 148
 149 #ifndef HAVE_ARCH_WARN_ON
 150 #define WARN_ON(condition) ({                                           \
 151         int __ret_warn_on = !!(condition);                              \
 152         unlikely(__ret_warn_on);                                        \
 153 })
 154 #endif
 155
 156 #ifndef WARN
 157 #define WARN(condition, format...) ({                                   \
 158         int __ret_warn_on = !!(condition);                              \
 159         no_printk(format);                                              \
 160         unlikely(__ret_warn_on);                                        \
 161 })
 162 #endif
 163
 164 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 165 #define WARN_ONCE(condition, format...) WARN(condition, format)
 166 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 167 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 168
 169 #endif
 170
 171 /*
 172  * WARN_ON_SMP() is for cases that the warning is either
 173  * meaningless for !SMP or may even cause failures.
 174  * This is usually used for cases that we have
 175  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 176  * returns 0 for uniprocessor settings.
 177  * It can also be used with values that are only defined
 178  * on SMP:
 179  *
 180  * struct foo {
 181  *  [...]
 182  * #ifdef CONFIG_SMP
 183  *      int bar;
 184  * #endif
 185  * };
 186  *
 187  * void func(struct foo *zoot)
 188  * {
 189  *      WARN_ON_SMP(!zoot->bar);
 190  *
 191  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 192  * and should be a nop and return false for uniprocessor.
 193  *
 194  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 195  * and x is true.
 196  */
 197 #ifdef CONFIG_SMP
 198 # define WARN_ON_SMP(x)                 WARN_ON(x)
 199 #else
 200 /*
 201  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 202  * a stand alone line statement or as a condition in an if ()
 203  * statement.
 204  * A simple "0" would cause gcc to give a "statement has no effect"
 205  * warning.
 206  */
 207 # define WARN_ON_SMP(x)                 ({0;})
 208 #endif
 209
 210 #endif /* __ASSEMBLY__ */
 211
 212 #endif