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         panic("BUG!"); \
  51 } while (0)
  52 #endif
  53
  54 #ifndef HAVE_ARCH_BUG_ON
  55 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  56 #endif
  57
  58 /*
  59  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  60  * significant issues that need prompt attention if they should ever
  61  * appear at runtime.  Use the versions with printk format strings
  62  * to provide better diagnostics.
  63  */
  64 #ifndef __WARN_TAINT
  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 #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 /* used internally by panic.c */
  85 struct warn_args;
  86
  87 void __warn(const char *file, int line, void *caller, unsigned taint,
  88             struct pt_regs *regs, struct warn_args *args);
  89
  90 #ifndef WARN_ON
  91 #define WARN_ON(condition) ({                                           \
  92         int __ret_warn_on = !!(condition);                              \
  93         if (unlikely(__ret_warn_on))                                    \
  94                 __WARN();                                               \
  95         unlikely(__ret_warn_on);                                        \
  96 })
  97 #endif
  98
  99 #ifndef WARN
 100 #define WARN(condition, format...) ({                                           \
 101         int __ret_warn_on = !!(condition);                              \
 102         if (unlikely(__ret_warn_on))                                    \
 103                 __WARN_printf(format);                                  \
 104         unlikely(__ret_warn_on);                                        \
 105 })
 106 #endif
 107
 108 #define WARN_TAINT(condition, taint, format...) ({                      \
 109         int __ret_warn_on = !!(condition);                              \
 110         if (unlikely(__ret_warn_on))                                    \
 111                 __WARN_printf_taint(taint, format);                     \
 112         unlikely(__ret_warn_on);                                        \
 113 })
 114
 115 #define WARN_ON_ONCE(condition) ({                              \
 116         static bool __section(.data.unlikely) __warned;         \
 117         int __ret_warn_once = !!(condition);                    \
 118                                                                 \
 119         if (unlikely(__ret_warn_once && !__warned)) {           \
 120                 __warned = true;                                \
 121                 WARN_ON(1);                                     \
 122         }                                                       \
 123         unlikely(__ret_warn_once);                              \
 124 })
 125
 126 #define WARN_ONCE(condition, format...) ({                      \
 127         static bool __section(.data.unlikely) __warned;         \
 128         int __ret_warn_once = !!(condition);                    \
 129                                                                 \
 130         if (unlikely(__ret_warn_once && !__warned)) {           \
 131                 __warned = true;                                \
 132                 WARN(1, format);                                \
 133         }                                                       \
 134         unlikely(__ret_warn_once);                              \
 135 })
 136
 137 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 138         static bool __section(.data.unlikely) __warned;         \
 139         int __ret_warn_once = !!(condition);                    \
 140                                                                 \
 141         if (unlikely(__ret_warn_once && !__warned)) {           \
 142                 __warned = true;                                \
 143                 WARN_TAINT(1, taint, format);                   \
 144         }                                                       \
 145         unlikely(__ret_warn_once);                              \
 146 })
 147
 148 #else /* !CONFIG_BUG */
 149 #ifndef HAVE_ARCH_BUG
 150 #define BUG() do {} while (1)
 151 #endif
 152
 153 #ifndef HAVE_ARCH_BUG_ON
 154 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 155 #endif
 156
 157 #ifndef HAVE_ARCH_WARN_ON
 158 #define WARN_ON(condition) ({                                           \
 159         int __ret_warn_on = !!(condition);                              \
 160         unlikely(__ret_warn_on);                                        \
 161 })
 162 #endif
 163
 164 #ifndef WARN
 165 #define WARN(condition, format...) ({                                   \
 166         int __ret_warn_on = !!(condition);                              \
 167         no_printk(format);                                              \
 168         unlikely(__ret_warn_on);                                        \
 169 })
 170 #endif
 171
 172 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 173 #define WARN_ONCE(condition, format...) WARN(condition, format)
 174 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 175 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 176
 177 #endif
 178
 179 /*
 180  * WARN_ON_SMP() is for cases that the warning is either
 181  * meaningless for !SMP or may even cause failures.
 182  * This is usually used for cases that we have
 183  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 184  * returns 0 for uniprocessor settings.
 185  * It can also be used with values that are only defined
 186  * on SMP:
 187  *
 188  * struct foo {
 189  *  [...]
 190  * #ifdef CONFIG_SMP
 191  *      int bar;
 192  * #endif
 193  * };
 194  *
 195  * void func(struct foo *zoot)
 196  * {
 197  *      WARN_ON_SMP(!zoot->bar);
 198  *
 199  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 200  * and should be a nop and return false for uniprocessor.
 201  *
 202  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 203  * and x is true.
 204  */
 205 #ifdef CONFIG_SMP
 206 # define WARN_ON_SMP(x)                 WARN_ON(x)
 207 #else
 208 /*
 209  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 210  * a stand alone line statement or as a condition in an if ()
 211  * statement.
 212  * A simple "0" would cause gcc to give a "statement has no effect"
 213  * warning.
 214  */
 215 # define WARN_ON_SMP(x)                 ({0;})
 216 #endif
 217
 218 #endif /* __ASSEMBLY__ */
 219
 220 #endif