LXR linux/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
  18struct 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
  65extern __printf(3, 4)
  66void warn_slowpath_fmt(const char *file, const int line,
  67                       const char *fmt, ...);
  68extern __printf(4, 5)
  69void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
  70                             const char *fmt, ...);
  71extern 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 */
  85struct warn_args;
  86
  87void __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
 221