bug.h

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#ifndef _ASM_GENERIC_BUG_H
#define _ASM_GENERIC_BUG_H

#include <linux/compiler.h>

#ifdef CONFIG_GENERIC_BUG
#define BUGFLAG_WARNING     (1 << 0)
#define BUGFLAG_TAINT(taint)    (BUGFLAG_WARNING | ((taint) << 8))
#define BUG_GET_TAINT(bug)  ((bug)->flags >> 8)
#endif

#ifndef __ASSEMBLY__
#include <linux/kernel.h>

#ifdef CONFIG_BUG

#ifdef CONFIG_GENERIC_BUG
struct bug_entry {
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
    unsigned long   bug_addr;
#else
    signed int  bug_addr_disp;
#endif
#ifdef CONFIG_DEBUG_BUGVERBOSE
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
    const char  *file;
#else
    signed int  file_disp;
#endif
    unsigned short  line;
#endif
    unsigned short  flags;
};
#endif  /* CONFIG_GENERIC_BUG */

/*
 * Don't use BUG() or BUG_ON() unless there's really no way out; one
 * example might be detecting data structure corruption in the middle
 * of an operation that can't be backed out of.  If the (sub)system
 * can somehow continue operating, perhaps with reduced functionality,
 * it's probably not BUG-worthy.
 *
 * If you're tempted to BUG(), think again:  is completely giving up
 * really the *only* solution?  There are usually better options, where
 * users don't need to reboot ASAP and can mostly shut down cleanly.
 */
#ifndef HAVE_ARCH_BUG
#define BUG() do { \
    printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
    panic("BUG!"); \
} while (0)
#endif

#ifndef HAVE_ARCH_BUG_ON
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
#endif

/*
 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
 * significant issues that need prompt attention if they should ever
 * appear at runtime.  Use the versions with printk format strings
 * to provide better diagnostics.
 */
#ifndef __WARN_TAINT
extern __printf(3, 4)
void warn_slowpath_fmt(const char *file, const int line,
               const char *fmt, ...);
extern __printf(4, 5)
void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint,
                 const char *fmt, ...);
extern void warn_slowpath_null(const char *file, const int line);
#define WANT_WARN_ON_SLOWPATH
#define __WARN()        warn_slowpath_null(__FILE__, __LINE__)
#define __WARN_printf(arg...)   warn_slowpath_fmt(__FILE__, __LINE__, arg)
#define __WARN_printf_taint(taint, arg...)              \
    warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
#else
#define __WARN()        __WARN_TAINT(TAINT_WARN)
#define __WARN_printf(arg...)   do { printk(arg); __WARN(); } while (0)
#define __WARN_printf_taint(taint, arg...)              \
    do { printk(arg); __WARN_TAINT(taint); } while (0)
#endif

#ifndef WARN_ON
#define WARN_ON(condition) ({                       \
    int __ret_warn_on = !!(condition);              \
    if (unlikely(__ret_warn_on))                    \
        __WARN();                       \
    unlikely(__ret_warn_on);                    \
})
#endif

#ifndef WARN
#define WARN(condition, format...) ({                       \
    int __ret_warn_on = !!(condition);              \
    if (unlikely(__ret_warn_on))                    \
        __WARN_printf(format);                  \
    unlikely(__ret_warn_on);                    \
})
#endif

#define WARN_TAINT(condition, taint, format...) ({          \
    int __ret_warn_on = !!(condition);              \
    if (unlikely(__ret_warn_on))                    \
        __WARN_printf_taint(taint, format);         \
    unlikely(__ret_warn_on);                    \
})

#else /* !CONFIG_BUG */
#ifndef HAVE_ARCH_BUG
#define BUG() do {} while(0)
#endif

#ifndef HAVE_ARCH_BUG_ON
#define BUG_ON(condition) do { if (condition) ; } while(0)
#endif

#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON(condition) ({                       \
    int __ret_warn_on = !!(condition);              \
    unlikely(__ret_warn_on);                    \
})
#endif

#ifndef WARN
#define WARN(condition, format...) ({                   \
    int __ret_warn_on = !!(condition);              \
    unlikely(__ret_warn_on);                    \
})
#endif

#define WARN_TAINT(condition, taint, format...) WARN_ON(condition)

#endif

#define WARN_ON_ONCE(condition) ({              \
    static bool __section(.data.unlikely) __warned;     \
    int __ret_warn_once = !!(condition);            \
                                \
    if (unlikely(__ret_warn_once))              \
        if (WARN_ON(!__warned))             \
            __warned = true;            \
    unlikely(__ret_warn_once);              \
})

#define WARN_ONCE(condition, format...) ({          \
    static bool __section(.data.unlikely) __warned;     \
    int __ret_warn_once = !!(condition);            \
                                \
    if (unlikely(__ret_warn_once))              \
        if (WARN(!__warned, format))            \
            __warned = true;            \
    unlikely(__ret_warn_once);              \
})

#define WARN_TAINT_ONCE(condition, taint, format...)    ({  \
    static bool __section(.data.unlikely) __warned;     \
    int __ret_warn_once = !!(condition);            \
                                \
    if (unlikely(__ret_warn_once))              \
        if (WARN_TAINT(!__warned, taint, format))   \
            __warned = true;            \
    unlikely(__ret_warn_once);              \
})

/*
 * WARN_ON_SMP() is for cases that the warning is either
 * meaningless for !SMP or may even cause failures.
 * This is usually used for cases that we have
 * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
 * returns 0 for uniprocessor settings.
 * It can also be used with values that are only defined
 * on SMP:
 *
 * struct foo {
 *  [...]
 * #ifdef CONFIG_SMP
 *  int bar;
 * #endif
 * };
 *
 * void func(struct foo *zoot)
 * {
 *  WARN_ON_SMP(!zoot->bar);
 *
 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
 * and should be a nop and return false for uniprocessor.
 *
 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
 * and x is true.
 */
#ifdef CONFIG_SMP
# define WARN_ON_SMP(x)         WARN_ON(x)
#else
/*
 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
 * a stand alone line statement or as a condition in an if ()
 * statement.
 * A simple "0" would cause gcc to give a "statement has no effect"
 * warning.
 */
# define WARN_ON_SMP(x)         ({0;})
#endif

#endif /* __ASSEMBLY__ */

#endif