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_ONCE            (1 << 1)
   9 #define BUGFLAG_DONE            (1 << 2)
  10 #define BUGFLAG_TAINT(taint)    ((taint) << 8)
  11 #define BUG_GET_TAINT(bug)      ((bug)->flags >> 8)
  12 #endif
  13
  14 #ifndef __ASSEMBLY__
  15 #include <linux/kernel.h>
  16
  17 #ifdef CONFIG_BUG
  18
  19 #ifdef CONFIG_GENERIC_BUG
  20 struct bug_entry {
  21 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  22         unsigned long   bug_addr;
  23 #else
  24         signed int      bug_addr_disp;
  25 #endif
  26 #ifdef CONFIG_DEBUG_BUGVERBOSE
  27 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  28         const char      *file;
  29 #else
  30         signed int      file_disp;
  31 #endif
  32         unsigned short  line;
  33 #endif
  34         unsigned short  flags;
  35 };
  36 #endif  /* CONFIG_GENERIC_BUG */
  37
  38 /*
  39  * Don't use BUG() or BUG_ON() unless there's really no way out; one
  40  * example might be detecting data structure corruption in the middle
  41  * of an operation that can't be backed out of.  If the (sub)system
  42  * can somehow continue operating, perhaps with reduced functionality,
  43  * it's probably not BUG-worthy.
  44  *
  45  * If you're tempted to BUG(), think again:  is completely giving up
  46  * really the *only* solution?  There are usually better options, where
  47  * users don't need to reboot ASAP and can mostly shut down cleanly.
  48  */
  49 #ifndef HAVE_ARCH_BUG
  50 #define BUG() do { \
  51         printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
  52         panic("BUG!"); \
  53 } while (0)
  54 #endif
  55
  56 #ifndef HAVE_ARCH_BUG_ON
  57 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
  58 #endif
  59
  60 #ifdef __WARN_FLAGS
  61 #define __WARN_TAINT(taint)             __WARN_FLAGS(BUGFLAG_TAINT(taint))
  62 #define __WARN_ONCE_TAINT(taint)        __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
  63
  64 #define WARN_ON_ONCE(condition) ({                              \
  65         int __ret_warn_on = !!(condition);                      \
  66         if (unlikely(__ret_warn_on))                            \
  67                 __WARN_ONCE_TAINT(TAINT_WARN);                  \
  68         unlikely(__ret_warn_on);                                \
  69 })
  70 #endif
  71
  72 /*
  73  * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
  74  * significant issues that need prompt attention if they should ever
  75  * appear at runtime.  Use the versions with printk format strings
  76  * to provide better diagnostics.
  77  */
  78 #ifndef __WARN_TAINT
  79 extern __printf(3, 4)
  80 void warn_slowpath_fmt(const char *file, const int line,
  81                        const char *fmt, ...);
  82 extern __printf(4, 5)
  83 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  84                              const char *fmt, ...);
  85 extern void warn_slowpath_null(const char *file, const int line);
  86 #define WANT_WARN_ON_SLOWPATH
  87 #define __WARN()                warn_slowpath_null(__FILE__, __LINE__)
  88 #define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
  89 #define __WARN_printf_taint(taint, arg...)                              \
  90         warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
  91 #else
  92 #define __WARN()                __WARN_TAINT(TAINT_WARN)
  93 #define __WARN_printf(arg...)   do { printk(arg); __WARN(); } while (0)
  94 #define __WARN_printf_taint(taint, arg...)                              \
  95         do { printk(arg); __WARN_TAINT(taint); } while (0)
  96 #endif
  97
  98 /* used internally by panic.c */
  99 struct warn_args;
 100 struct pt_regs;
 101
 102 void __warn(const char *file, int line, void *caller, unsigned taint,
 103             struct pt_regs *regs, struct warn_args *args);
 104
 105 #ifndef WARN_ON
 106 #define WARN_ON(condition) ({                                           \
 107         int __ret_warn_on = !!(condition);                              \
 108         if (unlikely(__ret_warn_on))                                    \
 109                 __WARN();                                               \
 110         unlikely(__ret_warn_on);                                        \
 111 })
 112 #endif
 113
 114 #ifndef WARN
 115 #define WARN(condition, format...) ({                                   \
 116         int __ret_warn_on = !!(condition);                              \
 117         if (unlikely(__ret_warn_on))                                    \
 118                 __WARN_printf(format);                                  \
 119         unlikely(__ret_warn_on);                                        \
 120 })
 121 #endif
 122
 123 #define WARN_TAINT(condition, taint, format...) ({                      \
 124         int __ret_warn_on = !!(condition);                              \
 125         if (unlikely(__ret_warn_on))                                    \
 126                 __WARN_printf_taint(taint, format);                     \
 127         unlikely(__ret_warn_on);                                        \
 128 })
 129
 130 #ifndef WARN_ON_ONCE
 131 #define WARN_ON_ONCE(condition) ({                              \
 132         static bool __section(.data.unlikely) __warned;         \
 133         int __ret_warn_once = !!(condition);                    \
 134                                                                 \
 135         if (unlikely(__ret_warn_once && !__warned)) {           \
 136                 __warned = true;                                \
 137                 WARN_ON(1);                                     \
 138         }                                                       \
 139         unlikely(__ret_warn_once);                              \
 140 })
 141 #endif
 142
 143 #define WARN_ONCE(condition, format...) ({                      \
 144         static bool __section(.data.unlikely) __warned;         \
 145         int __ret_warn_once = !!(condition);                    \
 146                                                                 \
 147         if (unlikely(__ret_warn_once && !__warned)) {           \
 148                 __warned = true;                                \
 149                 WARN(1, format);                                \
 150         }                                                       \
 151         unlikely(__ret_warn_once);                              \
 152 })
 153
 154 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 155         static bool __section(.data.unlikely) __warned;         \
 156         int __ret_warn_once = !!(condition);                    \
 157                                                                 \
 158         if (unlikely(__ret_warn_once && !__warned)) {           \
 159                 __warned = true;                                \
 160                 WARN_TAINT(1, taint, format);                   \
 161         }                                                       \
 162         unlikely(__ret_warn_once);                              \
 163 })
 164
 165 #else /* !CONFIG_BUG */
 166 #ifndef HAVE_ARCH_BUG
 167 #define BUG() do {} while (1)
 168 #endif
 169
 170 #ifndef HAVE_ARCH_BUG_ON
 171 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 172 #endif
 173
 174 #ifndef HAVE_ARCH_WARN_ON
 175 #define WARN_ON(condition) ({                                           \
 176         int __ret_warn_on = !!(condition);                              \
 177         unlikely(__ret_warn_on);                                        \
 178 })
 179 #endif
 180
 181 #ifndef WARN
 182 #define WARN(condition, format...) ({                                   \
 183         int __ret_warn_on = !!(condition);                              \
 184         no_printk(format);                                              \
 185         unlikely(__ret_warn_on);                                        \
 186 })
 187 #endif
 188
 189 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 190 #define WARN_ONCE(condition, format...) WARN(condition, format)
 191 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 192 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 193
 194 #endif
 195
 196 /*
 197  * WARN_ON_SMP() is for cases that the warning is either
 198  * meaningless for !SMP or may even cause failures.
 199  * This is usually used for cases that we have
 200  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 201  * returns 0 for uniprocessor settings.
 202  * It can also be used with values that are only defined
 203  * on SMP:
 204  *
 205  * struct foo {
 206  *  [...]
 207  * #ifdef CONFIG_SMP
 208  *      int bar;
 209  * #endif
 210  * };
 211  *
 212  * void func(struct foo *zoot)
 213  * {
 214  *      WARN_ON_SMP(!zoot->bar);
 215  *
 216  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 217  * and should be a nop and return false for uniprocessor.
 218  *
 219  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 220  * and x is true.
 221  */
 222 #ifdef CONFIG_SMP
 223 # define WARN_ON_SMP(x)                 WARN_ON(x)
 224 #else
 225 /*
 226  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 227  * a stand alone line statement or as a condition in an if ()
 228  * statement.
 229  * A simple "0" would cause gcc to give a "statement has no effect"
 230  * warning.
 231  */
 232 # define WARN_ON_SMP(x)                 ({0;})
 233 #endif
 234
 235 #endif /* __ASSEMBLY__ */
 236
 237 #endif