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kernel.h

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    kernel.h 21.99 KiB
    #ifndef _LINUX_KERNEL_H
    #define _LINUX_KERNEL_H
    
    /*
     * 'kernel.h' contains some often-used function prototypes etc
     */
    
    #ifdef __KERNEL__
    
    #include <stdarg.h>
    #include <linux/linkage.h>
    #include <linux/stddef.h>
    #include <linux/types.h>
    #include <linux/compiler.h>
    #include <linux/bitops.h>
    #include <linux/log2.h>
    #include <linux/typecheck.h>
    #include <linux/dynamic_debug.h>
    #include <asm/byteorder.h>
    #include <asm/bug.h>
    
    extern const char linux_banner[];
    extern const char linux_proc_banner[];
    
    #define USHORT_MAX	((u16)(~0U))
    #define SHORT_MAX	((s16)(USHORT_MAX>>1))
    #define SHORT_MIN	(-SHORT_MAX - 1)
    #define INT_MAX		((int)(~0U>>1))
    #define INT_MIN		(-INT_MAX - 1)
    #define UINT_MAX	(~0U)
    #define LONG_MAX	((long)(~0UL>>1))
    #define LONG_MIN	(-LONG_MAX - 1)
    #define ULONG_MAX	(~0UL)
    #define LLONG_MAX	((long long)(~0ULL>>1))
    #define LLONG_MIN	(-LLONG_MAX - 1)
    #define ULLONG_MAX	(~0ULL)
    
    #define STACK_MAGIC	0xdeadbeef
    
    #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
    #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
    #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
    #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
    
    #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
    
    #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
    #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
    #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
    #define DIV_ROUND_CLOSEST(x, divisor)(			\
    {							\
    	typeof(divisor) __divisor = divisor;		\
    	(((x) + ((__divisor) / 2)) / (__divisor));	\
    }							\
    )
    
    #define _RET_IP_		(unsigned long)__builtin_return_address(0)
    #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
    
    #ifdef CONFIG_LBDAF
    # include <asm/div64.h>
    # define sector_div(a, b) do_div(a, b)
    #else
    # define sector_div(n, b)( \
    { \
    	int _res; \
    	_res = (n) % (b); \
    	(n) /= (b); \
    	_res; \
    } \
    )
    #endif
    
    /**
     * upper_32_bits - return bits 32-63 of a number
     * @n: the number we're accessing
     *
     * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
     * the "right shift count >= width of type" warning when that quantity is
     * 32-bits.
     */
    #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
    
    /**
     * lower_32_bits - return bits 0-31 of a number
     * @n: the number we're accessing
     */
    #define lower_32_bits(n) ((u32)(n))
    
    #define	KERN_EMERG	"<0>"	/* system is unusable			*/
    #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
    #define	KERN_CRIT	"<2>"	/* critical conditions			*/
    #define	KERN_ERR	"<3>"	/* error conditions			*/
    #define	KERN_WARNING	"<4>"	/* warning conditions			*/
    #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
    #define	KERN_INFO	"<6>"	/* informational			*/
    #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
    
    /* Use the default kernel loglevel */
    #define KERN_DEFAULT	"<d>"
    /*
     * Annotation for a "continued" line of log printout (only done after a
     * line that had no enclosing \n). Only to be used by core/arch code
     * during early bootup (a continued line is not SMP-safe otherwise).
     */
    #define	KERN_CONT	"<c>"
    
    extern int console_printk[];
    
    #define console_loglevel (console_printk[0])
    #define default_message_loglevel (console_printk[1])
    #define minimum_console_loglevel (console_printk[2])
    #define default_console_loglevel (console_printk[3])
    
    struct completion;
    struct pt_regs;
    struct user;
    
    #ifdef CONFIG_PREEMPT_VOLUNTARY
    extern int _cond_resched(void);
    # define might_resched() _cond_resched()
    #else
    # define might_resched() do { } while (0)
    #endif
    
    #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
      void __might_sleep(char *file, int line, int preempt_offset);
    /**
     * might_sleep - annotation for functions that can sleep
     *
     * this macro will print a stack trace if it is executed in an atomic
     * context (spinlock, irq-handler, ...).
     *
     * This is a useful debugging help to be able to catch problems early and not
     * be bitten later when the calling function happens to sleep when it is not
     * supposed to.
     */
    # define might_sleep() \
    	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
    #else
      static inline void __might_sleep(char *file, int line, int preempt_offset) { }
    # define might_sleep() do { might_resched(); } while (0)
    #endif
    
    #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
    
    #define abs(x) ({				\
    		long __x = (x);			\
    		(__x < 0) ? -__x : __x;		\
    	})
    
    #ifdef CONFIG_PROVE_LOCKING
    void might_fault(void);
    #else
    static inline void might_fault(void)
    {
    	might_sleep();
    }
    #endif
    
    extern struct atomic_notifier_head panic_notifier_list;
    extern long (*panic_blink)(long time);
    NORET_TYPE void panic(const char * fmt, ...)
    	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
    extern void oops_enter(void);
    extern void oops_exit(void);
    extern int oops_may_print(void);
    NORET_TYPE void do_exit(long error_code)
    	ATTRIB_NORET;
    NORET_TYPE void complete_and_exit(struct completion *, long)
    	ATTRIB_NORET;
    extern unsigned long simple_strtoul(const char *,char **,unsigned int);
    extern long simple_strtol(const char *,char **,unsigned int);
    extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
    extern long long simple_strtoll(const char *,char **,unsigned int);
    extern int strict_strtoul(const char *, unsigned int, unsigned long *);
    extern int strict_strtol(const char *, unsigned int, long *);
    extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
    extern int strict_strtoll(const char *, unsigned int, long long *);
    extern int sprintf(char * buf, const char * fmt, ...)
    	__attribute__ ((format (printf, 2, 3)));
    extern int vsprintf(char *buf, const char *, va_list)
    	__attribute__ ((format (printf, 2, 0)));
    extern int snprintf(char * buf, size_t size, const char * fmt, ...)
    	__attribute__ ((format (printf, 3, 4)));
    extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
    	__attribute__ ((format (printf, 3, 0)));
    extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
    	__attribute__ ((format (printf, 3, 4)));
    extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
    	__attribute__ ((format (printf, 3, 0)));
    extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
    	__attribute__ ((format (printf, 2, 3)));
    extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
    
    extern int sscanf(const char *, const char *, ...)
    	__attribute__ ((format (scanf, 2, 3)));
    extern int vsscanf(const char *, const char *, va_list)
    	__attribute__ ((format (scanf, 2, 0)));
    
    extern int get_option(char **str, int *pint);
    extern char *get_options(const char *str, int nints, int *ints);
    extern unsigned long long memparse(const char *ptr, char **retptr);
    
    extern int core_kernel_text(unsigned long addr);
    extern int __kernel_text_address(unsigned long addr);
    extern int kernel_text_address(unsigned long addr);
    extern int func_ptr_is_kernel_text(void *ptr);
    
    struct pid;
    extern struct pid *session_of_pgrp(struct pid *pgrp);
    
    /*
     * FW_BUG
     * Add this to a message where you are sure the firmware is buggy or behaves
     * really stupid or out of spec. Be aware that the responsible BIOS developer
     * should be able to fix this issue or at least get a concrete idea of the
     * problem by reading your message without the need of looking at the kernel
     * code.
     * 
     * Use it for definite and high priority BIOS bugs.
     *
     * FW_WARN
     * Use it for not that clear (e.g. could the kernel messed up things already?)
     * and medium priority BIOS bugs.
     *
     * FW_INFO
     * Use this one if you want to tell the user or vendor about something
     * suspicious, but generally harmless related to the firmware.
     *
     * Use it for information or very low priority BIOS bugs.
     */
    #define FW_BUG		"[Firmware Bug]: "
    #define FW_WARN		"[Firmware Warn]: "
    #define FW_INFO		"[Firmware Info]: "
    
    #ifdef CONFIG_PRINTK
    asmlinkage int vprintk(const char *fmt, va_list args)
    	__attribute__ ((format (printf, 1, 0)));
    asmlinkage int printk(const char * fmt, ...)
    	__attribute__ ((format (printf, 1, 2))) __cold;
    
    extern int __printk_ratelimit(const char *func);
    #define printk_ratelimit() __printk_ratelimit(__func__)
    extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
    				   unsigned int interval_msec);
    
    extern int printk_delay_msec;
    
    /*
     * Print a one-time message (analogous to WARN_ONCE() et al):
     */
    #define printk_once(x...) ({			\
    	static bool __print_once = true;	\
    						\
    	if (__print_once) {			\
    		__print_once = false;		\
    		printk(x);			\
    	}					\
    })
    
    void log_buf_kexec_setup(void);
    #else
    static inline int vprintk(const char *s, va_list args)
    	__attribute__ ((format (printf, 1, 0)));
    static inline int vprintk(const char *s, va_list args) { return 0; }
    static inline int printk(const char *s, ...)
    	__attribute__ ((format (printf, 1, 2)));
    static inline int __cold printk(const char *s, ...) { return 0; }
    static inline int printk_ratelimit(void) { return 0; }
    static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
    					  unsigned int interval_msec)	\
    		{ return false; }
    
    /* No effect, but we still get type checking even in the !PRINTK case: */
    #define printk_once(x...) printk(x)
    
    static inline void log_buf_kexec_setup(void)
    {
    }
    #endif
    
    extern int printk_needs_cpu(int cpu);
    extern void printk_tick(void);
    
    extern void asmlinkage __attribute__((format(printf, 1, 2)))
    	early_printk(const char *fmt, ...);
    
    unsigned long int_sqrt(unsigned long);
    
    static inline void console_silent(void)
    {
    	console_loglevel = 0;
    }
    
    static inline void console_verbose(void)
    {
    	if (console_loglevel)
    		console_loglevel = 15;
    }
    
    extern void bust_spinlocks(int yes);
    extern void wake_up_klogd(void);
    extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
    extern int panic_timeout;
    extern int panic_on_oops;
    extern int panic_on_unrecovered_nmi;
    extern int panic_on_io_nmi;
    extern const char *print_tainted(void);
    extern void add_taint(unsigned flag);
    extern int test_taint(unsigned flag);
    extern unsigned long get_taint(void);
    extern int root_mountflags;
    
    /* Values used for system_state */
    extern enum system_states {
    	SYSTEM_BOOTING,
    	SYSTEM_RUNNING,
    	SYSTEM_HALT,
    	SYSTEM_POWER_OFF,
    	SYSTEM_RESTART,
    	SYSTEM_SUSPEND_DISK,
    } system_state;
    
    #define TAINT_PROPRIETARY_MODULE	0
    #define TAINT_FORCED_MODULE		1
    #define TAINT_UNSAFE_SMP		2
    #define TAINT_FORCED_RMMOD		3
    #define TAINT_MACHINE_CHECK		4
    #define TAINT_BAD_PAGE			5
    #define TAINT_USER			6
    #define TAINT_DIE			7
    #define TAINT_OVERRIDDEN_ACPI_TABLE	8
    #define TAINT_WARN			9
    #define TAINT_CRAP			10
    
    extern void dump_stack(void) __cold;
    
    enum {
    	DUMP_PREFIX_NONE,
    	DUMP_PREFIX_ADDRESS,
    	DUMP_PREFIX_OFFSET
    };
    extern void hex_dump_to_buffer(const void *buf, size_t len,
    				int rowsize, int groupsize,
    				char *linebuf, size_t linebuflen, bool ascii);
    extern void print_hex_dump(const char *level, const char *prefix_str,
    				int prefix_type, int rowsize, int groupsize,
    				const void *buf, size_t len, bool ascii);
    extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
    			const void *buf, size_t len);
    
    extern const char hex_asc[];
    #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
    #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
    
    static inline char *pack_hex_byte(char *buf, u8 byte)
    {
    	*buf++ = hex_asc_hi(byte);
    	*buf++ = hex_asc_lo(byte);
    	return buf;
    }
    
    #ifndef pr_fmt
    #define pr_fmt(fmt) fmt
    #endif
    
    #define pr_emerg(fmt, ...) \
            printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_alert(fmt, ...) \
            printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_crit(fmt, ...) \
            printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_err(fmt, ...) \
            printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_warning(fmt, ...) \
            printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_notice(fmt, ...) \
            printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_info(fmt, ...) \
            printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
    #define pr_cont(fmt, ...) \
    	printk(KERN_CONT fmt, ##__VA_ARGS__)
    
    /* pr_devel() should produce zero code unless DEBUG is defined */
    #ifdef DEBUG
    #define pr_devel(fmt, ...) \
    	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
    #else
    #define pr_devel(fmt, ...) \
    	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
    #endif
    
    /* If you are writing a driver, please use dev_dbg instead */
    #if defined(DEBUG)
    #define pr_debug(fmt, ...) \
    	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
    #elif defined(CONFIG_DYNAMIC_DEBUG)
    /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
    #define pr_debug(fmt, ...) do { \
    	dynamic_pr_debug(fmt, ##__VA_ARGS__); \
    	} while (0)
    #else
    #define pr_debug(fmt, ...) \
    	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
    #endif
    
    /*
     * General tracing related utility functions - trace_printk(),
     * tracing_on/tracing_off and tracing_start()/tracing_stop
     *
     * Use tracing_on/tracing_off when you want to quickly turn on or off
     * tracing. It simply enables or disables the recording of the trace events.
     * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
     * file, which gives a means for the kernel and userspace to interact.
     * Place a tracing_off() in the kernel where you want tracing to end.
     * From user space, examine the trace, and then echo 1 > tracing_on
     * to continue tracing.
     *
     * tracing_stop/tracing_start has slightly more overhead. It is used
     * by things like suspend to ram where disabling the recording of the
     * trace is not enough, but tracing must actually stop because things
     * like calling smp_processor_id() may crash the system.
     *
     * Most likely, you want to use tracing_on/tracing_off.
     */
    #ifdef CONFIG_RING_BUFFER
    void tracing_on(void);
    void tracing_off(void);
    /* trace_off_permanent stops recording with no way to bring it back */
    void tracing_off_permanent(void);
    int tracing_is_on(void);
    #else
    static inline void tracing_on(void) { }
    static inline void tracing_off(void) { }
    static inline void tracing_off_permanent(void) { }
    static inline int tracing_is_on(void) { return 0; }
    #endif
    #ifdef CONFIG_TRACING
    extern void tracing_start(void);
    extern void tracing_stop(void);
    extern void ftrace_off_permanent(void);
    
    extern void
    ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
    
    static inline void __attribute__ ((format (printf, 1, 2)))
    ____trace_printk_check_format(const char *fmt, ...)
    {
    }
    #define __trace_printk_check_format(fmt, args...)			\
    do {									\
    	if (0)								\
    		____trace_printk_check_format(fmt, ##args);		\
    } while (0)
    
    /**
     * trace_printk - printf formatting in the ftrace buffer
     * @fmt: the printf format for printing
     *
     * Note: __trace_printk is an internal function for trace_printk and
     *       the @ip is passed in via the trace_printk macro.
     *
     * This function allows a kernel developer to debug fast path sections
     * that printk is not appropriate for. By scattering in various
     * printk like tracing in the code, a developer can quickly see
     * where problems are occurring.
     *
     * This is intended as a debugging tool for the developer only.
     * Please refrain from leaving trace_printks scattered around in
     * your code.
     */
    
    #define trace_printk(fmt, args...)					\
    do {									\
    	__trace_printk_check_format(fmt, ##args);			\
    	if (__builtin_constant_p(fmt)) {				\
    		static const char *trace_printk_fmt			\
    		  __attribute__((section("__trace_printk_fmt"))) =	\
    			__builtin_constant_p(fmt) ? fmt : NULL;		\
    									\
    		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
    	} else								\
    		__trace_printk(_THIS_IP_, fmt, ##args);		\
    } while (0)
    
    extern int
    __trace_bprintk(unsigned long ip, const char *fmt, ...)
    	__attribute__ ((format (printf, 2, 3)));
    
    extern int
    __trace_printk(unsigned long ip, const char *fmt, ...)
    	__attribute__ ((format (printf, 2, 3)));
    
    extern void trace_dump_stack(void);
    
    /*
     * The double __builtin_constant_p is because gcc will give us an error
     * if we try to allocate the static variable to fmt if it is not a
     * constant. Even with the outer if statement.
     */
    #define ftrace_vprintk(fmt, vargs)					\
    do {									\
    	if (__builtin_constant_p(fmt)) {				\
    		static const char *trace_printk_fmt			\
    		  __attribute__((section("__trace_printk_fmt"))) =	\
    			__builtin_constant_p(fmt) ? fmt : NULL;		\
    									\
    		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
    	} else								\
    		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
    } while (0)
    
    extern int
    __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
    
    extern int
    __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
    
    extern void ftrace_dump(void);
    #else
    static inline void
    ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
    static inline int
    trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
    
    static inline void tracing_start(void) { }
    static inline void tracing_stop(void) { }
    static inline void ftrace_off_permanent(void) { }
    static inline int
    trace_printk(const char *fmt, ...)
    {
    	return 0;
    }
    static inline int
    ftrace_vprintk(const char *fmt, va_list ap)
    {
    	return 0;
    }
    static inline void ftrace_dump(void) { }
    #endif /* CONFIG_TRACING */
    
    /*
     *      Display an IP address in readable format.
     */
    
    #define NIPQUAD(addr) \
    	((unsigned char *)&addr)[0], \
    	((unsigned char *)&addr)[1], \
    	((unsigned char *)&addr)[2], \
    	((unsigned char *)&addr)[3]
    #define NIPQUAD_FMT "%u.%u.%u.%u"
    
    /*
     * min()/max()/clamp() macros that also do
     * strict type-checking.. See the
     * "unnecessary" pointer comparison.
     */
    #define min(x, y) ({				\
    	typeof(x) _min1 = (x);			\
    	typeof(y) _min2 = (y);			\
    	(void) (&_min1 == &_min2);		\
    	_min1 < _min2 ? _min1 : _min2; })
    
    #define max(x, y) ({				\
    	typeof(x) _max1 = (x);			\
    	typeof(y) _max2 = (y);			\
    	(void) (&_max1 == &_max2);		\
    	_max1 > _max2 ? _max1 : _max2; })
    
    /**
     * clamp - return a value clamped to a given range with strict typechecking
     * @val: current value
     * @min: minimum allowable value
     * @max: maximum allowable value
     *
     * This macro does strict typechecking of min/max to make sure they are of the
     * same type as val.  See the unnecessary pointer comparisons.
     */
    #define clamp(val, min, max) ({			\
    	typeof(val) __val = (val);		\
    	typeof(min) __min = (min);		\
    	typeof(max) __max = (max);		\
    	(void) (&__val == &__min);		\
    	(void) (&__val == &__max);		\
    	__val = __val < __min ? __min: __val;	\
    	__val > __max ? __max: __val; })
    
    /*
     * ..and if you can't take the strict
     * types, you can specify one yourself.
     *
     * Or not use min/max/clamp at all, of course.
     */
    #define min_t(type, x, y) ({			\
    	type __min1 = (x);			\
    	type __min2 = (y);			\
    	__min1 < __min2 ? __min1: __min2; })
    
    #define max_t(type, x, y) ({			\
    	type __max1 = (x);			\
    	type __max2 = (y);			\
    	__max1 > __max2 ? __max1: __max2; })
    
    /**
     * clamp_t - return a value clamped to a given range using a given type
     * @type: the type of variable to use
     * @val: current value
     * @min: minimum allowable value
     * @max: maximum allowable value
     *
     * This macro does no typechecking and uses temporary variables of type
     * 'type' to make all the comparisons.
     */
    #define clamp_t(type, val, min, max) ({		\
    	type __val = (val);			\
    	type __min = (min);			\
    	type __max = (max);			\
    	__val = __val < __min ? __min: __val;	\
    	__val > __max ? __max: __val; })
    
    /**
     * clamp_val - return a value clamped to a given range using val's type
     * @val: current value
     * @min: minimum allowable value
     * @max: maximum allowable value
     *
     * This macro does no typechecking and uses temporary variables of whatever
     * type the input argument 'val' is.  This is useful when val is an unsigned
     * type and min and max are literals that will otherwise be assigned a signed
     * integer type.
     */
    #define clamp_val(val, min, max) ({		\
    	typeof(val) __val = (val);		\
    	typeof(val) __min = (min);		\
    	typeof(val) __max = (max);		\
    	__val = __val < __min ? __min: __val;	\
    	__val > __max ? __max: __val; })
    
    
    /*
     * swap - swap value of @a and @b
     */
    #define swap(a, b) \
    	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
    
    /**
     * container_of - cast a member of a structure out to the containing structure
     * @ptr:	the pointer to the member.
     * @type:	the type of the container struct this is embedded in.
     * @member:	the name of the member within the struct.
     *
     */
    #define container_of(ptr, type, member) ({			\
    	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
    	(type *)( (char *)__mptr - offsetof(type,member) );})
    
    struct sysinfo;
    extern int do_sysinfo(struct sysinfo *info);
    
    #endif /* __KERNEL__ */
    
    #ifndef __EXPORTED_HEADERS__
    #ifndef __KERNEL__
    #warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders
    #endif /* __KERNEL__ */
    #endif /* __EXPORTED_HEADERS__ */
    
    #define SI_LOAD_SHIFT	16
    struct sysinfo {
    	long uptime;			/* Seconds since boot */
    	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
    	unsigned long totalram;		/* Total usable main memory size */
    	unsigned long freeram;		/* Available memory size */
    	unsigned long sharedram;	/* Amount of shared memory */
    	unsigned long bufferram;	/* Memory used by buffers */
    	unsigned long totalswap;	/* Total swap space size */
    	unsigned long freeswap;		/* swap space still available */
    	unsigned short procs;		/* Number of current processes */
    	unsigned short pad;		/* explicit padding for m68k */
    	unsigned long totalhigh;	/* Total high memory size */
    	unsigned long freehigh;		/* Available high memory size */
    	unsigned int mem_unit;		/* Memory unit size in bytes */
    	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
    };
    
    /* Force a compilation error if condition is true */
    #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
    
    /* Force a compilation error if condition is constant and true */
    #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
    
    /* Force a compilation error if condition is true, but also produce a
       result (of value 0 and type size_t), so the expression can be used
       e.g. in a structure initializer (or where-ever else comma expressions
       aren't permitted). */
    #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
    #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
    
    /* Trap pasters of __FUNCTION__ at compile-time */
    #define __FUNCTION__ (__func__)
    
    /* This helps us to avoid #ifdef CONFIG_NUMA */
    #ifdef CONFIG_NUMA
    #define NUMA_BUILD 1
    #else
    #define NUMA_BUILD 0
    #endif
    
    /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
    #ifdef CONFIG_FTRACE_MCOUNT_RECORD
    # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
    #endif
    
    #endif