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
 101 void __warn(const char *file, int line, void *caller, unsigned taint,
 102             struct pt_regs *regs, struct warn_args *args);
 103
 104 #ifndef WARN_ON
 105 #define WARN_ON(condition) ({                                           \
 106         int __ret_warn_on = !!(condition);                              \
 107         if (unlikely(__ret_warn_on))                                    \
 108                 __WARN();                                               \
 109         unlikely(__ret_warn_on);                                        \
 110 })
 111 #endif
 112
 113 #ifndef WARN
 114 #define WARN(condition, format...) ({                                   \
 115         int __ret_warn_on = !!(condition);                              \
 116         if (unlikely(__ret_warn_on))                                    \
 117                 __WARN_printf(format);                                  \
 118         unlikely(__ret_warn_on);                                        \
 119 })
 120 #endif
 121
 122 #define WARN_TAINT(condition, taint, format...) ({                      \
 123         int __ret_warn_on = !!(condition);                              \
 124         if (unlikely(__ret_warn_on))                                    \
 125                 __WARN_printf_taint(taint, format);                     \
 126         unlikely(__ret_warn_on);                                        \
 127 })
 128
 129 #ifndef WARN_ON_ONCE
 130 #define WARN_ON_ONCE(condition) ({                              \
 131         static bool __section(.data.unlikely) __warned;         \
 132         int __ret_warn_once = !!(condition);                    \
 133                                                                 \
 134         if (unlikely(__ret_warn_once && !__warned)) {           \
 135                 __warned = true;                                \
 136                 WARN_ON(1);                                     \
 137         }                                                       \
 138         unlikely(__ret_warn_once);                              \
 139 })
 140 #endif
 141
 142 #define WARN_ONCE(condition, format...) ({                      \
 143         static bool __section(.data.unlikely) __warned;         \
 144         int __ret_warn_once = !!(condition);                    \
 145                                                                 \
 146         if (unlikely(__ret_warn_once && !__warned)) {           \
 147                 __warned = true;                                \
 148                 WARN(1, format);                                \
 149         }                                                       \
 150         unlikely(__ret_warn_once);                              \
 151 })
 152
 153 #define WARN_TAINT_ONCE(condition, taint, format...)    ({      \
 154         static bool __section(.data.unlikely) __warned;         \
 155         int __ret_warn_once = !!(condition);                    \
 156                                                                 \
 157         if (unlikely(__ret_warn_once && !__warned)) {           \
 158                 __warned = true;                                \
 159                 WARN_TAINT(1, taint, format);                   \
 160         }                                                       \
 161         unlikely(__ret_warn_once);                              \
 162 })
 163
 164 #else /* !CONFIG_BUG */
 165 #ifndef HAVE_ARCH_BUG
 166 #define BUG() do {} while (1)
 167 #endif
 168
 169 #ifndef HAVE_ARCH_BUG_ON
 170 #define BUG_ON(condition) do { if (condition) BUG(); } while (0)
 171 #endif
 172
 173 #ifndef HAVE_ARCH_WARN_ON
 174 #define WARN_ON(condition) ({                                           \
 175         int __ret_warn_on = !!(condition);                              \
 176         unlikely(__ret_warn_on);                                        \
 177 })
 178 #endif
 179
 180 #ifndef WARN
 181 #define WARN(condition, format...) ({                                   \
 182         int __ret_warn_on = !!(condition);                              \
 183         no_printk(format);                                              \
 184         unlikely(__ret_warn_on);                                        \
 185 })
 186 #endif
 187
 188 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 189 #define WARN_ONCE(condition, format...) WARN(condition, format)
 190 #define WARN_TAINT(condition, taint, format...) WARN(condition, format)
 191 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
 192
 193 #endif
 194
 195 /*
 196  * WARN_ON_SMP() is for cases that the warning is either
 197  * meaningless for !SMP or may even cause failures.
 198  * This is usually used for cases that we have
 199  * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 200  * returns 0 for uniprocessor settings.
 201  * It can also be used with values that are only defined
 202  * on SMP:
 203  *
 204  * struct foo {
 205  *  [...]
 206  * #ifdef CONFIG_SMP
 207  *      int bar;
 208  * #endif
 209  * };
 210  *
 211  * void func(struct foo *zoot)
 212  * {
 213  *      WARN_ON_SMP(!zoot->bar);
 214  *
 215  * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 216  * and should be a nop and return false for uniprocessor.
 217  *
 218  * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 219  * and x is true.
 220  */
 221 #ifdef CONFIG_SMP
 222 # define WARN_ON_SMP(x)                 WARN_ON(x)
 223 #else
 224 /*
 225  * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 226  * a stand alone line statement or as a condition in an if ()
 227  * statement.
 228  * A simple "0" would cause gcc to give a "statement has no effect"
 229  * warning.
 230  */
 231 # define WARN_ON_SMP(x)                 ({0;})
 232 #endif
 233
 234 #endif /* __ASSEMBLY__ */
 235
 236 #endif