linux/include/asm-generic/bug.h

#ifndef _ASM_GENERIC_BUG_H
#define _ASM_GENERIC_BUG_H

#include <linux/compiler.h>

#ifdef CONFIG_BUG
#ifndef HAVE_ARCH_BUG
#define BUG() do { \
	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __FUNCTION__); \
	panic("BUG!"); \
} while (0)
#endif

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

#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON(condition) do { \
	if (unlikely((condition)!=0)) { \
		printk("BUG: warning at %s:%d/%s()\n", __FILE__, __LINE__, __FUNCTION__); \
		dump_stack(); \
	} \
} while (0)
#endif

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

#define WARN_ON_ONCE(condition)				\
({							\
	static int __warn_once = 1;			\
	int __ret = 0;					\
							\
	if (unlikely((condition) && __warn_once)) {	\
		__warn_once = 0;			\
		WARN_ON(1);				\
		__ret = 1;				\
	}						\
	__ret;						\
})

#ifdef CONFIG_SMP
# define WARN_ON_SMP(x)			WARN_ON(x)
#else
# define WARN_ON_SMP(x)			do { } while (0)
#endif

#endif