include/linux/ftrace.h - kernel/msm-4.19 - Gitiles

 #ifndef _LINUX_FTRACE_H
 #define _LINUX_FTRACE_H

 #include <linux/linkage.h>
 #include <linux/fs.h>
 #include <linux/ktime.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
 #include <linux/bitops.h>
 #include <linux/sched.h>

 #ifdef CONFIG_FUNCTION_TRACER

 extern int ftrace_enabled;
 extern int
 ftrace_enable_sysctl(struct ctl_table *table, int write,
 		     struct file *filp, void __user *buffer, size_t *lenp,
 		     loff_t *ppos);

 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

 struct ftrace_ops {
 	ftrace_func_t	  func;
 	struct ftrace_ops *next;
 };

 extern int function_trace_stop;

 /*
  * Type of the current tracing.
  */
 enum ftrace_tracing_type_t {
 	FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 	FTRACE_TYPE_RETURN,	/* Hook the return of the function */
 };

 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 extern enum ftrace_tracing_type_t ftrace_tracing_type;

 /**
  * ftrace_stop - stop function tracer.
  *
  * A quick way to stop the function tracer. Note this an on off switch,
  * it is not something that is recursive like preempt_disable.
  * This does not disable the calling of mcount, it only stops the
  * calling of functions from mcount.
  */
 static inline void ftrace_stop(void)
 {
 	function_trace_stop = 1;
 }

 /**
  * ftrace_start - start the function tracer.
  *
  * This function is the inverse of ftrace_stop. This does not enable
  * the function tracing if the function tracer is disabled. This only
  * sets the function tracer flag to continue calling the functions
  * from mcount.
  */
 static inline void ftrace_start(void)
 {
 	function_trace_stop = 0;
 }

 /*
  * The ftrace_ops must be a static and should also
  * be read_mostly.  These functions do modify read_mostly variables
  * so use them sparely. Never free an ftrace_op or modify the
  * next pointer after it has been registered. Even after unregistering
  * it, the next pointer may still be used internally.
  */
 int register_ftrace_function(struct ftrace_ops *ops);
 int unregister_ftrace_function(struct ftrace_ops *ops);
 void clear_ftrace_function(void);

 extern void ftrace_stub(unsigned long a0, unsigned long a1);

 #else /* !CONFIG_FUNCTION_TRACER */
 # define register_ftrace_function(ops) do { } while (0)
 # define unregister_ftrace_function(ops) do { } while (0)
 # define clear_ftrace_function(ops) do { } while (0)
 static inline void ftrace_kill(void) { }
 static inline void ftrace_stop(void) { }
 static inline void ftrace_start(void) { }
 #endif /* CONFIG_FUNCTION_TRACER */

 #ifdef CONFIG_STACK_TRACER
 extern int stack_tracer_enabled;
 int
 stack_trace_sysctl(struct ctl_table *table, int write,
 		   struct file *file, void __user *buffer, size_t *lenp,
 		   loff_t *ppos);
 #endif

 #ifdef CONFIG_DYNAMIC_FTRACE
 /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
 #include <asm/ftrace.h>

 enum {
 	FTRACE_FL_FREE		= (1 << 0),
 	FTRACE_FL_FAILED	= (1 << 1),
 	FTRACE_FL_FILTER	= (1 << 2),
 	FTRACE_FL_ENABLED	= (1 << 3),
 	FTRACE_FL_NOTRACE	= (1 << 4),
 	FTRACE_FL_CONVERTED	= (1 << 5),
 	FTRACE_FL_FROZEN	= (1 << 6),
 };

 struct dyn_ftrace {
 	struct list_head	list;
 	unsigned long		ip; /* address of mcount call-site */
 	unsigned long		flags;
 	struct dyn_arch_ftrace	arch;
 };

 int ftrace_force_update(void);
 void ftrace_set_filter(unsigned char *buf, int len, int reset);

 /* defined in arch */
 extern int ftrace_ip_converted(unsigned long ip);
 extern int ftrace_dyn_arch_init(void *data);
 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 extern void ftrace_caller(void);
 extern void ftrace_call(void);
 extern void mcount_call(void);

 #ifndef FTRACE_ADDR
 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 #endif
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 extern void ftrace_graph_caller(void);
 extern int ftrace_enable_ftrace_graph_caller(void);
 extern int ftrace_disable_ftrace_graph_caller(void);
 #else
 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 #endif

 /**
  * ftrace_make_nop - convert code into top
  * @mod: module structure if called by module load initialization
  * @rec: the mcount call site record
  * @addr: the address that the call site should be calling
  *
  * This is a very sensitive operation and great care needs
  * to be taken by the arch.  The operation should carefully
  * read the location, check to see if what is read is indeed
  * what we expect it to be, and then on success of the compare,
  * it should write to the location.
  *
  * The code segment at @rec->ip should be a caller to @addr
  *
  * Return must be:
  *  0 on success
  *  -EFAULT on error reading the location
  *  -EINVAL on a failed compare of the contents
  *  -EPERM  on error writing to the location
  * Any other value will be considered a failure.
  */
 extern int ftrace_make_nop(struct module *mod,
 			   struct dyn_ftrace *rec, unsigned long addr);

 /**
  * ftrace_make_call - convert a nop call site into a call to addr
  * @rec: the mcount call site record
  * @addr: the address that the call site should call
  *
  * This is a very sensitive operation and great care needs
  * to be taken by the arch.  The operation should carefully
  * read the location, check to see if what is read is indeed
  * what we expect it to be, and then on success of the compare,
  * it should write to the location.
  *
  * The code segment at @rec->ip should be a nop
  *
  * Return must be:
  *  0 on success
  *  -EFAULT on error reading the location
  *  -EINVAL on a failed compare of the contents
  *  -EPERM  on error writing to the location
  * Any other value will be considered a failure.
  */
 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);


 /* May be defined in arch */
 extern int ftrace_arch_read_dyn_info(char *buf, int size);

 extern int skip_trace(unsigned long ip);

 extern void ftrace_release(void *start, unsigned long size);

 extern void ftrace_disable_daemon(void);
 extern void ftrace_enable_daemon(void);
 #else
 # define skip_trace(ip)				({ 0; })
 # define ftrace_force_update()			({ 0; })
 # define ftrace_set_filter(buf, len, reset)	do { } while (0)
 # define ftrace_disable_daemon()		do { } while (0)
 # define ftrace_enable_daemon()			do { } while (0)
 static inline void ftrace_release(void *start, unsigned long size) { }
 #endif /* CONFIG_DYNAMIC_FTRACE */

 /* totally disable ftrace - can not re-enable after this */
 void ftrace_kill(void);

 static inline void tracer_disable(void)
 {
 #ifdef CONFIG_FUNCTION_TRACER
 	ftrace_enabled = 0;
 #endif
 }

 /*
  * Ftrace disable/restore without lock. Some synchronization mechanism
  * must be used to prevent ftrace_enabled to be changed between
  * disable/restore.
  */
 static inline int __ftrace_enabled_save(void)
 {
 #ifdef CONFIG_FUNCTION_TRACER
 	int saved_ftrace_enabled = ftrace_enabled;
 	ftrace_enabled = 0;
 	return saved_ftrace_enabled;
 #else
 	return 0;
 #endif
 }

 static inline void __ftrace_enabled_restore(int enabled)
 {
 #ifdef CONFIG_FUNCTION_TRACER
 	ftrace_enabled = enabled;
 #endif
 }

 #ifdef CONFIG_FRAME_POINTER
 /* TODO: need to fix this for ARM */
 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 #else
 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 # define CALLER_ADDR1 0UL
 # define CALLER_ADDR2 0UL
 # define CALLER_ADDR3 0UL
 # define CALLER_ADDR4 0UL
 # define CALLER_ADDR5 0UL
 # define CALLER_ADDR6 0UL
 #endif

 #ifdef CONFIG_IRQSOFF_TRACER
   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 #else
 # define time_hardirqs_on(a0, a1)		do { } while (0)
 # define time_hardirqs_off(a0, a1)		do { } while (0)
 #endif

 #ifdef CONFIG_PREEMPT_TRACER
   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 #else
 # define trace_preempt_on(a0, a1)		do { } while (0)
 # define trace_preempt_off(a0, a1)		do { } while (0)
 #endif

 #ifdef CONFIG_TRACING
 extern int ftrace_dump_on_oops;

 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);

 /**
  * ftrace_printk - printf formatting in the ftrace buffer
  * @fmt: the printf format for printing
  *
  * Note: __ftrace_printk is an internal function for ftrace_printk and
  *       the @ip is passed in via the ftrace_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 ftrace_printks scattered around in
  * your code.
  */
 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
 extern int
 __ftrace_printk(unsigned long ip, const char *fmt, ...)
 	__attribute__ ((format (printf, 2, 3)));
 extern void ftrace_dump(void);
 #else
 static inline void
 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 static inline int
 ftrace_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
 ftrace_printk(const char *fmt, ...)
 {
 	return 0;
 }
 static inline void ftrace_dump(void) { }
 #endif

 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 extern void ftrace_init(void);
 extern void ftrace_init_module(struct module *mod,
 			       unsigned long *start, unsigned long *end);
 #else
 static inline void ftrace_init(void) { }
 static inline void
 ftrace_init_module(struct module *mod,
 		   unsigned long *start, unsigned long *end) { }
 #endif

 enum {
 	POWER_NONE = 0,
 	POWER_CSTATE = 1,
 	POWER_PSTATE = 2,
 };

 struct power_trace {
 #ifdef CONFIG_POWER_TRACER
 	ktime_t			stamp;
 	ktime_t			end;
 	int			type;
 	int			state;
 #endif
 };

 #ifdef CONFIG_POWER_TRACER
 extern void trace_power_start(struct power_trace *it, unsigned int type,
 					unsigned int state);
 extern void trace_power_mark(struct power_trace *it, unsigned int type,
 					unsigned int state);
 extern void trace_power_end(struct power_trace *it);
 #else
 static inline void trace_power_start(struct power_trace *it, unsigned int type,
 					unsigned int state) { }
 static inline void trace_power_mark(struct power_trace *it, unsigned int type,
 					unsigned int state) { }
 static inline void trace_power_end(struct power_trace *it) { }
 #endif


 /*
  * Structure that defines an entry function trace.
  */
 struct ftrace_graph_ent {
 	unsigned long func; /* Current function */
 	int depth;
 };

 /*
  * Structure that defines a return function trace.
  */
 struct ftrace_graph_ret {
 	unsigned long func; /* Current function */
 	unsigned long long calltime;
 	unsigned long long rettime;
 	/* Number of functions that overran the depth limit for current task */
 	unsigned long overrun;
 	int depth;
 };

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER

 /*
  * Sometimes we don't want to trace a function with the function
  * graph tracer but we want them to keep traced by the usual function
  * tracer if the function graph tracer is not configured.
  */
 #define __notrace_funcgraph		notrace

 /*
  * We want to which function is an entrypoint of a hardirq.
  * That will help us to put a signal on output.
  */
 #define __irq_entry		 __attribute__((__section__(".irqentry.text")))

 /* Limits of hardirq entrypoints */
 extern char __irqentry_text_start[];
 extern char __irqentry_text_end[];

 #define FTRACE_RETFUNC_DEPTH 50
 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 /* Type of the callback handlers for tracing function graph*/
 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */

 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 				trace_func_graph_ent_t entryfunc);

 extern void ftrace_graph_stop(void);

 /* The current handlers in use */
 extern trace_func_graph_ret_t ftrace_graph_return;
 extern trace_func_graph_ent_t ftrace_graph_entry;

 extern void unregister_ftrace_graph(void);

 extern void ftrace_graph_init_task(struct task_struct *t);
 extern void ftrace_graph_exit_task(struct task_struct *t);

 static inline int task_curr_ret_stack(struct task_struct *t)
 {
 	return t->curr_ret_stack;
 }

 static inline void pause_graph_tracing(void)
 {
 	atomic_inc(&current->tracing_graph_pause);
 }

 static inline void unpause_graph_tracing(void)
 {
 	atomic_dec(&current->tracing_graph_pause);
 }
 #else

 #define __notrace_funcgraph
 #define __irq_entry

 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 static inline void ftrace_graph_exit_task(struct task_struct *t) { }

 static inline int task_curr_ret_stack(struct task_struct *tsk)
 {
 	return -1;
 }

 static inline void pause_graph_tracing(void) { }
 static inline void unpause_graph_tracing(void) { }
 #endif

 #ifdef CONFIG_TRACING
 #include <linux/sched.h>

 /* flags for current->trace */
 enum {
 	TSK_TRACE_FL_TRACE_BIT	= 0,
 	TSK_TRACE_FL_GRAPH_BIT	= 1,
 };
 enum {
 	TSK_TRACE_FL_TRACE	= 1 << TSK_TRACE_FL_TRACE_BIT,
 	TSK_TRACE_FL_GRAPH	= 1 << TSK_TRACE_FL_GRAPH_BIT,
 };

 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 {
 	set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 }

 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 {
 	clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 }

 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 {
 	return tsk->trace & TSK_TRACE_FL_TRACE;
 }

 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 {
 	set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 }

 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 {
 	clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 }

 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 {
 	return tsk->trace & TSK_TRACE_FL_GRAPH;
 }

 #endif /* CONFIG_TRACING */


 #ifdef CONFIG_HW_BRANCH_TRACER

 void trace_hw_branch(u64 from, u64 to);
 void trace_hw_branch_oops(void);

 #else /* CONFIG_HW_BRANCH_TRACER */

 static inline void trace_hw_branch(u64 from, u64 to) {}
 static inline void trace_hw_branch_oops(void) {}

 #endif /* CONFIG_HW_BRANCH_TRACER */

 #endif /* _LINUX_FTRACE_H */
	#ifndef _LINUX_FTRACE_H
	#define _LINUX_FTRACE_H

	#include <linux/linkage.h>
	#include <linux/fs.h>
	#include <linux/ktime.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/module.h>
	#include <linux/kallsyms.h>
	#include <linux/bitops.h>
	#include <linux/sched.h>

	#ifdef CONFIG_FUNCTION_TRACER

	extern int ftrace_enabled;
	extern int
	ftrace_enable_sysctl(struct ctl_table *table, int write,
	struct file filp, void __user buffer, size_t *lenp,
	loff_t *ppos);

	typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

	struct ftrace_ops {
	ftrace_func_t func;
	struct ftrace_ops *next;
	};

	extern int function_trace_stop;

	/*
	* Type of the current tracing.
	*/
	enum ftrace_tracing_type_t {
	FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
	FTRACE_TYPE_RETURN, /* Hook the return of the function */
	};

	/* Current tracing type, default is FTRACE_TYPE_ENTER */
	extern enum ftrace_tracing_type_t ftrace_tracing_type;

	/**
	* ftrace_stop - stop function tracer.
	*
	* A quick way to stop the function tracer. Note this an on off switch,
	* it is not something that is recursive like preempt_disable.
	* This does not disable the calling of mcount, it only stops the
	* calling of functions from mcount.
	*/
	static inline void ftrace_stop(void)
	{
	function_trace_stop = 1;
	}

	/**
	* ftrace_start - start the function tracer.
	*
	* This function is the inverse of ftrace_stop. This does not enable
	* the function tracing if the function tracer is disabled. This only
	* sets the function tracer flag to continue calling the functions
	* from mcount.
	*/
	static inline void ftrace_start(void)
	{
	function_trace_stop = 0;
	}

	/*
	* The ftrace_ops must be a static and should also
	* be read_mostly. These functions do modify read_mostly variables
	* so use them sparely. Never free an ftrace_op or modify the
	* next pointer after it has been registered. Even after unregistering
	* it, the next pointer may still be used internally.
	*/
	int register_ftrace_function(struct ftrace_ops *ops);
	int unregister_ftrace_function(struct ftrace_ops *ops);
	void clear_ftrace_function(void);

	extern void ftrace_stub(unsigned long a0, unsigned long a1);

	#else /* !CONFIG_FUNCTION_TRACER */
	# define register_ftrace_function(ops) do { } while (0)
	# define unregister_ftrace_function(ops) do { } while (0)
	# define clear_ftrace_function(ops) do { } while (0)
	static inline void ftrace_kill(void) { }
	static inline void ftrace_stop(void) { }
	static inline void ftrace_start(void) { }
	#endif /* CONFIG_FUNCTION_TRACER */

	#ifdef CONFIG_STACK_TRACER
	extern int stack_tracer_enabled;
	int
	stack_trace_sysctl(struct ctl_table *table, int write,
	struct file file, void __user buffer, size_t *lenp,
	loff_t *ppos);
	#endif

	#ifdef CONFIG_DYNAMIC_FTRACE
	/* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
	#include <asm/ftrace.h>

	enum {
	FTRACE_FL_FREE = (1 << 0),
	FTRACE_FL_FAILED = (1 << 1),
	FTRACE_FL_FILTER = (1 << 2),
	FTRACE_FL_ENABLED = (1 << 3),
	FTRACE_FL_NOTRACE = (1 << 4),
	FTRACE_FL_CONVERTED = (1 << 5),
	FTRACE_FL_FROZEN = (1 << 6),
	};

	struct dyn_ftrace {
	struct list_head list;
	unsigned long ip; /* address of mcount call-site */
	unsigned long flags;
	struct dyn_arch_ftrace arch;
	};

	int ftrace_force_update(void);
	void ftrace_set_filter(unsigned char *buf, int len, int reset);

	/* defined in arch */
	extern int ftrace_ip_converted(unsigned long ip);
	extern int ftrace_dyn_arch_init(void *data);
	extern int ftrace_update_ftrace_func(ftrace_func_t func);
	extern void ftrace_caller(void);
	extern void ftrace_call(void);
	extern void mcount_call(void);

	#ifndef FTRACE_ADDR
	#define FTRACE_ADDR ((unsigned long)ftrace_caller)
	#endif
	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	extern void ftrace_graph_caller(void);
	extern int ftrace_enable_ftrace_graph_caller(void);
	extern int ftrace_disable_ftrace_graph_caller(void);
	#else
	static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
	static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
	#endif

	/**
	* ftrace_make_nop - convert code into top
	* @mod: module structure if called by module load initialization
	* @rec: the mcount call site record
	* @addr: the address that the call site should be calling
	*
	* This is a very sensitive operation and great care needs
	* to be taken by the arch. The operation should carefully
	* read the location, check to see if what is read is indeed
	* what we expect it to be, and then on success of the compare,
	* it should write to the location.
	*
	* The code segment at @rec->ip should be a caller to @addr
	*
	* Return must be:
	* 0 on success
	* -EFAULT on error reading the location
	* -EINVAL on a failed compare of the contents
	* -EPERM on error writing to the location
	* Any other value will be considered a failure.
	*/
	extern int ftrace_make_nop(struct module *mod,
	struct dyn_ftrace *rec, unsigned long addr);

	/**
	* ftrace_make_call - convert a nop call site into a call to addr
	* @rec: the mcount call site record
	* @addr: the address that the call site should call
	*
	* This is a very sensitive operation and great care needs
	* to be taken by the arch. The operation should carefully
	* read the location, check to see if what is read is indeed
	* what we expect it to be, and then on success of the compare,
	* it should write to the location.
	*
	* The code segment at @rec->ip should be a nop
	*
	* Return must be:
	* 0 on success
	* -EFAULT on error reading the location
	* -EINVAL on a failed compare of the contents
	* -EPERM on error writing to the location
	* Any other value will be considered a failure.
	*/
	extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);


	/* May be defined in arch */
	extern int ftrace_arch_read_dyn_info(char *buf, int size);

	extern int skip_trace(unsigned long ip);

	extern void ftrace_release(void *start, unsigned long size);

	extern void ftrace_disable_daemon(void);
	extern void ftrace_enable_daemon(void);
	#else
	# define skip_trace(ip) ({ 0; })
	# define ftrace_force_update() ({ 0; })
	# define ftrace_set_filter(buf, len, reset) do { } while (0)
	# define ftrace_disable_daemon() do { } while (0)
	# define ftrace_enable_daemon() do { } while (0)
	static inline void ftrace_release(void *start, unsigned long size) { }
	#endif /* CONFIG_DYNAMIC_FTRACE */

	/* totally disable ftrace - can not re-enable after this */
	void ftrace_kill(void);

	static inline void tracer_disable(void)
	{
	#ifdef CONFIG_FUNCTION_TRACER
	ftrace_enabled = 0;
	#endif
	}

	/*
	* Ftrace disable/restore without lock. Some synchronization mechanism
	* must be used to prevent ftrace_enabled to be changed between
	* disable/restore.
	*/
	static inline int __ftrace_enabled_save(void)
	{
	#ifdef CONFIG_FUNCTION_TRACER
	int saved_ftrace_enabled = ftrace_enabled;
	ftrace_enabled = 0;
	return saved_ftrace_enabled;
	#else
	return 0;
	#endif
	}

	static inline void __ftrace_enabled_restore(int enabled)
	{
	#ifdef CONFIG_FUNCTION_TRACER
	ftrace_enabled = enabled;
	#endif
	}

	#ifdef CONFIG_FRAME_POINTER
	/* TODO: need to fix this for ARM */
	# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
	# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
	# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
	# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
	# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
	# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
	# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
	#else
	# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
	# define CALLER_ADDR1 0UL
	# define CALLER_ADDR2 0UL
	# define CALLER_ADDR3 0UL
	# define CALLER_ADDR4 0UL
	# define CALLER_ADDR5 0UL
	# define CALLER_ADDR6 0UL
	#endif

	#ifdef CONFIG_IRQSOFF_TRACER
	extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
	extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
	#else
	# define time_hardirqs_on(a0, a1) do { } while (0)
	# define time_hardirqs_off(a0, a1) do { } while (0)
	#endif

	#ifdef CONFIG_PREEMPT_TRACER
	extern void trace_preempt_on(unsigned long a0, unsigned long a1);
	extern void trace_preempt_off(unsigned long a0, unsigned long a1);
	#else
	# define trace_preempt_on(a0, a1) do { } while (0)
	# define trace_preempt_off(a0, a1) do { } while (0)
	#endif

	#ifdef CONFIG_TRACING
	extern int ftrace_dump_on_oops;

	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);

	/**
	* ftrace_printk - printf formatting in the ftrace buffer
	* @fmt: the printf format for printing
	*
	* Note: __ftrace_printk is an internal function for ftrace_printk and
	* the @ip is passed in via the ftrace_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 ftrace_printks scattered around in
	* your code.
	*/
	# define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
	extern int
	__ftrace_printk(unsigned long ip, const char *fmt, ...)
	__attribute__ ((format (printf, 2, 3)));
	extern void ftrace_dump(void);
	#else
	static inline void
	ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
	static inline int
	ftrace_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
	ftrace_printk(const char *fmt, ...)
	{
	return 0;
	}
	static inline void ftrace_dump(void) { }
	#endif

	#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	extern void ftrace_init(void);
	extern void ftrace_init_module(struct module *mod,
	unsigned long start, unsigned long end);
	#else
	static inline void ftrace_init(void) { }
	static inline void
	ftrace_init_module(struct module *mod,
	unsigned long start, unsigned long end) { }
	#endif

	enum {
	POWER_NONE = 0,
	POWER_CSTATE = 1,
	POWER_PSTATE = 2,
	};

	struct power_trace {
	#ifdef CONFIG_POWER_TRACER
	ktime_t stamp;
	ktime_t end;
	int type;
	int state;
	#endif
	};

	#ifdef CONFIG_POWER_TRACER
	extern void trace_power_start(struct power_trace *it, unsigned int type,
	unsigned int state);
	extern void trace_power_mark(struct power_trace *it, unsigned int type,
	unsigned int state);
	extern void trace_power_end(struct power_trace *it);
	#else
	static inline void trace_power_start(struct power_trace *it, unsigned int type,
	unsigned int state) { }
	static inline void trace_power_mark(struct power_trace *it, unsigned int type,
	unsigned int state) { }
	static inline void trace_power_end(struct power_trace *it) { }
	#endif


	/*
	* Structure that defines an entry function trace.
	*/
	struct ftrace_graph_ent {
	unsigned long func; /* Current function */
	int depth;
	};

	/*
	* Structure that defines a return function trace.
	*/
	struct ftrace_graph_ret {
	unsigned long func; /* Current function */
	unsigned long long calltime;
	unsigned long long rettime;
	/* Number of functions that overran the depth limit for current task */
	unsigned long overrun;
	int depth;
	};

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	/*
	* Sometimes we don't want to trace a function with the function
	* graph tracer but we want them to keep traced by the usual function
	* tracer if the function graph tracer is not configured.
	*/
	#define __notrace_funcgraph notrace

	/*
	* We want to which function is an entrypoint of a hardirq.
	* That will help us to put a signal on output.
	*/
	#define __irq_entry __attribute__((__section__(".irqentry.text")))

	/* Limits of hardirq entrypoints */
	extern char __irqentry_text_start[];
	extern char __irqentry_text_end[];

	#define FTRACE_RETFUNC_DEPTH 50
	#define FTRACE_RETSTACK_ALLOC_SIZE 32
	/* Type of the callback handlers for tracing function graph*/
	typedef void (trace_func_graph_ret_t)(struct ftrace_graph_ret ); /* return */
	typedef int (trace_func_graph_ent_t)(struct ftrace_graph_ent ); /* entry */

	extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
	trace_func_graph_ent_t entryfunc);

	extern void ftrace_graph_stop(void);

	/* The current handlers in use */
	extern trace_func_graph_ret_t ftrace_graph_return;
	extern trace_func_graph_ent_t ftrace_graph_entry;

	extern void unregister_ftrace_graph(void);

	extern void ftrace_graph_init_task(struct task_struct *t);
	extern void ftrace_graph_exit_task(struct task_struct *t);

	static inline int task_curr_ret_stack(struct task_struct *t)
	{
	return t->curr_ret_stack;
	}

	static inline void pause_graph_tracing(void)
	{
	atomic_inc(&current->tracing_graph_pause);
	}

	static inline void unpause_graph_tracing(void)
	{
	atomic_dec(&current->tracing_graph_pause);
	}
	#else

	#define __notrace_funcgraph
	#define __irq_entry

	static inline void ftrace_graph_init_task(struct task_struct *t) { }
	static inline void ftrace_graph_exit_task(struct task_struct *t) { }

	static inline int task_curr_ret_stack(struct task_struct *tsk)
	{
	return -1;
	}

	static inline void pause_graph_tracing(void) { }
	static inline void unpause_graph_tracing(void) { }
	#endif

	#ifdef CONFIG_TRACING
	#include <linux/sched.h>

	/* flags for current->trace */
	enum {
	TSK_TRACE_FL_TRACE_BIT = 0,
	TSK_TRACE_FL_GRAPH_BIT = 1,
	};
	enum {
	TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
	TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
	};

	static inline void set_tsk_trace_trace(struct task_struct *tsk)
	{
	set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
	}

	static inline void clear_tsk_trace_trace(struct task_struct *tsk)
	{
	clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
	}

	static inline int test_tsk_trace_trace(struct task_struct *tsk)
	{
	return tsk->trace & TSK_TRACE_FL_TRACE;
	}

	static inline void set_tsk_trace_graph(struct task_struct *tsk)
	{
	set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
	}

	static inline void clear_tsk_trace_graph(struct task_struct *tsk)
	{
	clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
	}

	static inline int test_tsk_trace_graph(struct task_struct *tsk)
	{
	return tsk->trace & TSK_TRACE_FL_GRAPH;
	}

	#endif /* CONFIG_TRACING */


	#ifdef CONFIG_HW_BRANCH_TRACER

	void trace_hw_branch(u64 from, u64 to);
	void trace_hw_branch_oops(void);

	#else /* CONFIG_HW_BRANCH_TRACER */

	static inline void trace_hw_branch(u64 from, u64 to) {}
	static inline void trace_hw_branch_oops(void) {}

	#endif /* CONFIG_HW_BRANCH_TRACER */

	#endif /* _LINUX_FTRACE_H */