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  • #ifndef _LINUX_KERNEL_TRACE_H
    #define _LINUX_KERNEL_TRACE_H
    
    #include <linux/fs.h>
    #include <asm/atomic.h>
    #include <linux/sched.h>
    #include <linux/clocksource.h>
    
    #include <linux/ring_buffer.h>
    
    #include <linux/mmiotrace.h>
    
    #include <linux/tracepoint.h>
    
    #include <linux/ftrace.h>
    
    #include <linux/trace_seq.h>
    
    enum trace_type {
    	__TRACE_FIRST_TYPE = 0,
    
    	TRACE_FN,
    	TRACE_CTX,
    	TRACE_WAKE,
    	TRACE_STACK,
    
    	TRACE_MMIO_RW,
    	TRACE_MMIO_MAP,
    
    	__TRACE_LAST_TYPE,
    
    #undef __field
    #define __field(type, item)		type	item;
    
    #undef __field_struct
    #define __field_struct(type, item)	__field(type, item)
    
    #undef __field_desc
    #define __field_desc(type, container, item)
    
    #undef __array
    #define __array(type, item, size)	type	item[size];
    
    #undef __array_desc
    #define __array_desc(type, container, item, size)
    
    #undef __dynamic_array
    #define __dynamic_array(type, item)	type	item[];
    
    #undef F_STRUCT
    #define F_STRUCT(args...)		args
    
    #undef FTRACE_ENTRY
    #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)	\
    	struct struct_name {					\
    		struct trace_entry	ent;			\
    		tstruct						\
    	}
    
    #undef TP_ARGS
    #define TP_ARGS(args...)	args
    
    #undef FTRACE_ENTRY_DUP
    #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
    
    /*
     * syscalls are special, and need special handling, this is why
     * they are not included in trace_entries.h
     */
    
    struct syscall_trace_enter {
    	struct trace_entry	ent;
    	int			nr;
    	unsigned long		args[];
    };
    
    struct syscall_trace_exit {
    	struct trace_entry	ent;
    	int			nr;
    
    struct kprobe_trace_entry_head {
    
    	struct trace_entry	ent;
    	unsigned long		ip;
    };
    
    
    struct kretprobe_trace_entry_head {
    
    	struct trace_entry	ent;
    	unsigned long		func;
    	unsigned long		ret_ip;
    };
    
    
    /*
     * trace_flag_type is an enumeration that holds different
     * states when a trace occurs. These are:
    
     *  IRQS_OFF		- interrupts were disabled
    
     *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
    
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     *  NEED_RESCHED	- reschedule is requested
    
     *  HARDIRQ		- inside an interrupt handler
     *  SOFTIRQ		- inside a softirq handler
    
     */
    enum trace_flag_type {
    	TRACE_FLAG_IRQS_OFF		= 0x01,
    
    	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
    	TRACE_FLAG_NEED_RESCHED		= 0x04,
    	TRACE_FLAG_HARDIRQ		= 0x08,
    	TRACE_FLAG_SOFTIRQ		= 0x10,
    
    #define TRACE_BUF_SIZE		1024
    
    
    /*
     * The CPU trace array - it consists of thousands of trace entries
     * plus some other descriptor data: (for example which task started
     * the trace, etc.)
     */
    struct trace_array_cpu {
    	atomic_t		disabled;
    
    	void			*buffer_page;	/* ring buffer spare */
    
    	unsigned long		saved_latency;
    	unsigned long		critical_start;
    	unsigned long		critical_end;
    	unsigned long		critical_sequence;
    	unsigned long		nice;
    	unsigned long		policy;
    	unsigned long		rt_priority;
    
    	unsigned long		skipped_entries;
    
    	cycle_t			preempt_timestamp;
    	pid_t			pid;
    	uid_t			uid;
    	char			comm[TASK_COMM_LEN];
    };
    
    /*
     * The trace array - an array of per-CPU trace arrays. This is the
     * highest level data structure that individual tracers deal with.
     * They have on/off state as well:
     */
    struct trace_array {
    
    	struct ring_buffer	*buffer;
    
    	unsigned long		entries;
    	int			cpu;
    	cycle_t			time_start;
    
    	struct task_struct	*waiter;
    
    	struct trace_array_cpu	*data[NR_CPUS];
    };
    
    
    #define FTRACE_CMP_TYPE(var, type) \
    	__builtin_types_compatible_p(typeof(var), type *)
    
    #undef IF_ASSIGN
    #define IF_ASSIGN(var, entry, etype, id)		\
    	if (FTRACE_CMP_TYPE(var, etype)) {		\
    		var = (typeof(var))(entry);		\
    		WARN_ON(id && (entry)->type != id);	\
    		break;					\
    	}
    
    /* Will cause compile errors if type is not found. */
    extern void __ftrace_bad_type(void);
    
    /*
     * The trace_assign_type is a verifier that the entry type is
     * the same as the type being assigned. To add new types simply
     * add a line with the following format:
     *
     * IF_ASSIGN(var, ent, type, id);
     *
     *  Where "type" is the trace type that includes the trace_entry
     *  as the "ent" item. And "id" is the trace identifier that is
     *  used in the trace_type enum.
     *
     *  If the type can have more than one id, then use zero.
     */
    #define trace_assign_type(var, ent)					\
    	do {								\
    		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
    		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
    		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
    
    		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
    
    		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
    
    		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
    
    		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
    			  TRACE_MMIO_RW);				\
    		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
    			  TRACE_MMIO_MAP);				\
    
    		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
    
    		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
    			  TRACE_GRAPH_ENT);		\
    		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
    			  TRACE_GRAPH_RET);		\
    
    		__ftrace_bad_type();					\
    	} while (0)
    
    /*
     * An option specific to a tracer. This is a boolean value.
     * The bit is the bit index that sets its value on the
     * flags value in struct tracer_flags.
     */
    struct tracer_opt {
    
    	const char	*name; /* Will appear on the trace_options file */
    	u32		bit; /* Mask assigned in val field in tracer_flags */
    
    };
    
    /*
     * The set of specific options for a tracer. Your tracer
     * have to set the initial value of the flags val.
     */
    struct tracer_flags {
    	u32			val;
    
    	struct tracer_opt	*opts;
    
    };
    
    /* Makes more easy to define a tracer opt */
    #define TRACER_OPT(s, b)	.name = #s, .bit = b
    
    
    /**
     * struct tracer - a specific tracer and its callbacks to interact with debugfs
     * @name: the name chosen to select it on the available_tracers file
     * @init: called when one switches to this tracer (echo name > current_tracer)
     * @reset: called when one switches to another tracer
     * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
     * @stop: called when tracing is paused (echo 0 > tracing_enabled)
     * @open: called when the trace file is opened
     * @pipe_open: called when the trace_pipe file is opened
     * @wait_pipe: override how the user waits for traces on trace_pipe
     * @close: called when the trace file is released
    
     * @pipe_close: called when the trace_pipe file is released
    
     * @read: override the default read callback on trace_pipe
     * @splice_read: override the default splice_read callback on trace_pipe
     * @selftest: selftest to run on boot (see trace_selftest.c)
     * @print_headers: override the first lines that describe your columns
     * @print_line: callback that prints a trace
     * @set_flag: signals one of your private flags changed (trace_options file)
     * @flags: your private flags
    
     */
    struct tracer {
    	const char		*name;
    
    	int			(*init)(struct trace_array *tr);
    
    	void			(*reset)(struct trace_array *tr);
    
    	void			(*start)(struct trace_array *tr);
    	void			(*stop)(struct trace_array *tr);
    
    	void			(*open)(struct trace_iterator *iter);
    
    	void			(*pipe_open)(struct trace_iterator *iter);
    
    	void			(*wait_pipe)(struct trace_iterator *iter);
    
    	void			(*close)(struct trace_iterator *iter);
    
    	void			(*pipe_close)(struct trace_iterator *iter);
    
    	ssize_t			(*read)(struct trace_iterator *iter,
    					struct file *filp, char __user *ubuf,
    					size_t cnt, loff_t *ppos);
    
    	ssize_t			(*splice_read)(struct trace_iterator *iter,
    					       struct file *filp,
    					       loff_t *ppos,
    					       struct pipe_inode_info *pipe,
    					       size_t len,
    					       unsigned int flags);
    
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    #ifdef CONFIG_FTRACE_STARTUP_TEST
    	int			(*selftest)(struct tracer *trace,
    					    struct trace_array *tr);
    #endif
    
    	enum print_line_t	(*print_line)(struct trace_iterator *iter);
    
    	/* If you handled the flag setting, return 0 */
    	int			(*set_flag)(u32 old_flags, u32 bit, int set);
    
    	struct tracer		*next;
    
    	struct tracer_flags	*flags;
    
    #define TRACE_PIPE_ALL_CPU	-1
    
    
    int tracer_init(struct tracer *t, struct trace_array *tr);
    
    int tracing_is_enabled(void);
    
    void trace_wake_up(void);
    
    void tracing_reset(struct trace_array *tr, int cpu);
    
    void tracing_reset_online_cpus(struct trace_array *tr);
    
    void tracing_reset_current(int cpu);
    void tracing_reset_current_online_cpus(void);
    
    int tracing_open_generic(struct inode *inode, struct file *filp);
    
    struct dentry *trace_create_file(const char *name,
    				 mode_t mode,
    				 struct dentry *parent,
    				 void *data,
    				 const struct file_operations *fops);
    
    
    struct dentry *tracing_init_dentry(void);
    
    struct ring_buffer_event *
    trace_buffer_lock_reserve(struct ring_buffer *buffer,
    			  int type,
    			  unsigned long len,
    			  unsigned long flags,
    			  int pc);
    void trace_buffer_unlock_commit(struct ring_buffer *buffer,
    
    				struct ring_buffer_event *event,
    				unsigned long flags, int pc);
    
    
    struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
    						struct trace_array_cpu *data);
    
    
    struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
    					  int *ent_cpu, u64 *ent_ts);
    
    
    int trace_empty(struct trace_iterator *iter);
    
    void *trace_find_next_entry_inc(struct trace_iterator *iter);
    
    void trace_init_global_iter(struct trace_iterator *iter);
    
    void tracing_iter_reset(struct trace_iterator *iter, int cpu);
    
    
    void default_wait_pipe(struct trace_iterator *iter);
    void poll_wait_pipe(struct trace_iterator *iter);
    
    
    void ftrace(struct trace_array *tr,
    			    struct trace_array_cpu *data,
    			    unsigned long ip,
    			    unsigned long parent_ip,
    
    			    unsigned long flags, int pc);
    
    void tracing_sched_switch_trace(struct trace_array *tr,
    				struct task_struct *prev,
    				struct task_struct *next,
    
    				unsigned long flags, int pc);
    
    
    void tracing_sched_wakeup_trace(struct trace_array *tr,
    				struct task_struct *wakee,
    				struct task_struct *cur,
    
    				unsigned long flags, int pc);
    
    void trace_function(struct trace_array *tr,
    		    unsigned long ip,
    		    unsigned long parent_ip,
    
    		    unsigned long flags, int pc);
    
    void trace_graph_function(struct trace_array *tr,
    		    unsigned long ip,
    		    unsigned long parent_ip,
    		    unsigned long flags, int pc);
    
    void trace_default_header(struct seq_file *m);
    void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
    int trace_empty(struct trace_iterator *iter);
    
    void trace_graph_return(struct ftrace_graph_ret *trace);
    
    int trace_graph_entry(struct ftrace_graph_ent *trace);
    
    void tracing_start_cmdline_record(void);
    void tracing_stop_cmdline_record(void);
    
    void tracing_sched_switch_assign_trace(struct trace_array *tr);
    void tracing_stop_sched_switch_record(void);
    void tracing_start_sched_switch_record(void);
    
    int register_tracer(struct tracer *type);
    void unregister_tracer(struct tracer *type);
    
    int is_tracing_stopped(void);
    
    enum trace_file_type {
    	TRACE_FILE_LAT_FMT	= 1,
    	TRACE_FILE_ANNOTATE	= 2,
    };
    
    extern cpumask_var_t __read_mostly tracing_buffer_mask;
    
    #define for_each_tracing_cpu(cpu)	\
    	for_each_cpu(cpu, tracing_buffer_mask)
    
    
    extern unsigned long nsecs_to_usecs(unsigned long nsecs);
    
    
    extern unsigned long tracing_thresh;
    
    
    extern unsigned long tracing_max_latency;
    
    void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
    void update_max_tr_single(struct trace_array *tr,
    			  struct task_struct *tsk, int cpu);
    
    #endif /* CONFIG_TRACER_MAX_TRACE */
    
    #ifdef CONFIG_STACKTRACE
    
    void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
    
    void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
    
    			    int pc);
    
    void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
    		   int pc);
    #else
    
    static inline void ftrace_trace_stack(struct ring_buffer *buffer,
    
    				      unsigned long flags, int skip, int pc)
    {
    }
    
    
    static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
    
    					  unsigned long flags, int pc)
    {
    }
    
    static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
    				 int skip, int pc)
    {
    }
    #endif /* CONFIG_STACKTRACE */
    
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    extern cycle_t ftrace_now(int cpu);
    
    extern void trace_find_cmdline(int pid, char comm[]);
    
    #ifdef CONFIG_DYNAMIC_FTRACE
    extern unsigned long ftrace_update_tot_cnt;
    
    #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
    extern int DYN_FTRACE_TEST_NAME(void);
    
    #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
    extern int DYN_FTRACE_TEST_NAME2(void);
    
    extern int ring_buffer_expanded;
    extern bool tracing_selftest_disabled;
    
    DECLARE_PER_CPU(int, ftrace_cpu_disabled);
    
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    #ifdef CONFIG_FTRACE_STARTUP_TEST
    extern int trace_selftest_startup_function(struct tracer *trace,
    					   struct trace_array *tr);
    
    extern int trace_selftest_startup_function_graph(struct tracer *trace,
    						 struct trace_array *tr);
    
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    extern int trace_selftest_startup_irqsoff(struct tracer *trace,
    					  struct trace_array *tr);
    extern int trace_selftest_startup_preemptoff(struct tracer *trace,
    					     struct trace_array *tr);
    extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
    						 struct trace_array *tr);
    extern int trace_selftest_startup_wakeup(struct tracer *trace,
    					 struct trace_array *tr);
    
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    extern int trace_selftest_startup_nop(struct tracer *trace,
    					 struct trace_array *tr);
    
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    extern int trace_selftest_startup_sched_switch(struct tracer *trace,
    					       struct trace_array *tr);
    
    extern int trace_selftest_startup_branch(struct tracer *trace,
    					 struct trace_array *tr);
    
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    #endif /* CONFIG_FTRACE_STARTUP_TEST */
    
    
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    extern void *head_page(struct trace_array_cpu *data);
    
    extern unsigned long long ns2usecs(cycle_t nsec);
    
    trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
    
    trace_vprintk(unsigned long ip, const char *fmt, va_list args);
    
    extern int
    trace_array_vprintk(struct trace_array *tr,
    		    unsigned long ip, const char *fmt, va_list args);
    int trace_array_printk(struct trace_array *tr,
    		       unsigned long ip, const char *fmt, ...);
    
    void trace_printk_seq(struct trace_seq *s);
    enum print_line_t print_trace_line(struct trace_iterator *iter);
    
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    extern unsigned long trace_flags;
    
    
    extern int trace_clock_id;
    
    
    /* Standard output formatting function used for function return traces */
    
    
    /* Flag options */
    #define TRACE_GRAPH_PRINT_OVERRUN       0x1
    #define TRACE_GRAPH_PRINT_CPU           0x2
    #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
    #define TRACE_GRAPH_PRINT_PROC          0x8
    #define TRACE_GRAPH_PRINT_DURATION      0x10
    #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
    
    
    extern enum print_line_t
    print_graph_function_flags(struct trace_iterator *iter, u32 flags);
    extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
    
    extern enum print_line_t
    trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
    
    extern void graph_trace_open(struct trace_iterator *iter);
    extern void graph_trace_close(struct trace_iterator *iter);
    extern int __trace_graph_entry(struct trace_array *tr,
    			       struct ftrace_graph_ent *trace,
    			       unsigned long flags, int pc);
    extern void __trace_graph_return(struct trace_array *tr,
    				 struct ftrace_graph_ret *trace,
    				 unsigned long flags, int pc);
    
    
    
    #ifdef CONFIG_DYNAMIC_FTRACE
    /* TODO: make this variable */
    #define FTRACE_GRAPH_MAX_FUNCS		32
    
    extern int ftrace_graph_filter_enabled;
    
    extern int ftrace_graph_count;
    extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
    
    static inline int ftrace_graph_addr(unsigned long addr)
    {
    	int i;
    
    
    	if (!ftrace_graph_filter_enabled)
    
    		return 1;
    
    	for (i = 0; i < ftrace_graph_count; i++) {
    		if (addr == ftrace_graph_funcs[i])
    			return 1;
    	}
    
    	return 0;
    }
    
    static inline int ftrace_graph_addr(unsigned long addr)
    {
    	return 1;
    
    }
    #endif /* CONFIG_DYNAMIC_FTRACE */
    #else /* CONFIG_FUNCTION_GRAPH_TRACER */
    
    print_graph_function_flags(struct trace_iterator *iter, u32 flags)
    
    #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
    
    extern struct list_head ftrace_pids;
    
    #ifdef CONFIG_FUNCTION_TRACER
    
    static inline int ftrace_trace_task(struct task_struct *task)
    {
    
    	if (list_empty(&ftrace_pids))
    
    		return 1;
    
    	return test_tsk_trace_trace(task);
    }
    
    #else
    static inline int ftrace_trace_task(struct task_struct *task)
    {
    	return 1;
    }
    #endif
    
    /*
     * struct trace_parser - servers for reading the user input separated by spaces
     * @cont: set if the input is not complete - no final space char was found
     * @buffer: holds the parsed user input
    
     * @idx: user input length
    
     * @size: buffer size
     */
    struct trace_parser {
    	bool		cont;
    	char		*buffer;
    	unsigned	idx;
    	unsigned	size;
    };
    
    static inline bool trace_parser_loaded(struct trace_parser *parser)
    {
    	return (parser->idx != 0);
    }
    
    static inline bool trace_parser_cont(struct trace_parser *parser)
    {
    	return parser->cont;
    }
    
    static inline void trace_parser_clear(struct trace_parser *parser)
    {
    	parser->cont = false;
    	parser->idx = 0;
    }
    
    extern int trace_parser_get_init(struct trace_parser *parser, int size);
    extern void trace_parser_put(struct trace_parser *parser);
    extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
    	size_t cnt, loff_t *ppos);
    
    
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    /*
     * trace_iterator_flags is an enumeration that defines bit
     * positions into trace_flags that controls the output.
     *
     * NOTE: These bits must match the trace_options array in
     *       trace.c.
     */
    
    enum trace_iterator_flags {
    	TRACE_ITER_PRINT_PARENT		= 0x01,
    	TRACE_ITER_SYM_OFFSET		= 0x02,
    	TRACE_ITER_SYM_ADDR		= 0x04,
    	TRACE_ITER_VERBOSE		= 0x08,
    	TRACE_ITER_RAW			= 0x10,
    	TRACE_ITER_HEX			= 0x20,
    	TRACE_ITER_BIN			= 0x40,
    	TRACE_ITER_BLOCK		= 0x80,
    	TRACE_ITER_STACKTRACE		= 0x100,
    
    	TRACE_ITER_PRINTK		= 0x200,
    	TRACE_ITER_PREEMPTONLY		= 0x400,
    	TRACE_ITER_BRANCH		= 0x800,
    	TRACE_ITER_ANNOTATE		= 0x1000,
    	TRACE_ITER_USERSTACKTRACE       = 0x2000,
    	TRACE_ITER_SYM_USEROBJ          = 0x4000,
    	TRACE_ITER_PRINTK_MSGONLY	= 0x8000,
    	TRACE_ITER_CONTEXT_INFO		= 0x10000, /* Print pid/cpu/time */
    	TRACE_ITER_LATENCY_FMT		= 0x20000,
    	TRACE_ITER_SLEEP_TIME		= 0x40000,
    	TRACE_ITER_GRAPH_TIME		= 0x80000,
    
    	TRACE_ITER_RECORD_CMD		= 0x100000,
    
    	TRACE_ITER_OVERWRITE		= 0x200000,
    
    /*
     * TRACE_ITER_SYM_MASK masks the options in trace_flags that
     * control the output of kernel symbols.
     */
    #define TRACE_ITER_SYM_MASK \
    	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
    
    
    extern struct tracer nop_trace;
    
    
    #ifdef CONFIG_BRANCH_TRACER
    
    extern int enable_branch_tracing(struct trace_array *tr);
    extern void disable_branch_tracing(void);
    static inline int trace_branch_enable(struct trace_array *tr)
    
    	if (trace_flags & TRACE_ITER_BRANCH)
    		return enable_branch_tracing(tr);
    
    static inline void trace_branch_disable(void)
    
    {
    	/* due to races, always disable */
    
    	disable_branch_tracing();
    
    static inline int trace_branch_enable(struct trace_array *tr)
    
    static inline void trace_branch_disable(void)
    
    #endif /* CONFIG_BRANCH_TRACER */
    
    /* set ring buffers to default size if not already done so */
    int tracing_update_buffers(void);
    
    
    /* trace event type bit fields, not numeric */
    enum {
    	TRACE_EVENT_TYPE_PRINTF		= 1,
    	TRACE_EVENT_TYPE_RAW		= 2,
    };
    
    
    struct ftrace_event_field {
    	struct list_head	link;
    	char			*name;
    	char			*type;
    
    struct event_filter {
    
    	int			n_preds;	/* Number assigned */
    	int			a_preds;	/* allocated */
    
    	struct filter_pred	*preds;
    
    	char			*filter_string;
    
    struct event_subsystem {
    	struct list_head	list;
    	const char		*name;
    	struct dentry		*entry;
    
    	struct event_filter	*filter;
    
    #define FILTER_PRED_INVALID	((unsigned short)-1)
    #define FILTER_PRED_IS_RIGHT	(1 << 15)
    
    #define FILTER_PRED_FOLD	(1 << 15)
    
    /*
     * The max preds is the size of unsigned short with
     * two flags at the MSBs. One bit is used for both the IS_RIGHT
     * and FOLD flags. The other is reserved.
     *
     * 2^14 preds is way more than enough.
     */
    #define MAX_FILTER_PRED		16384
    
    struct filter_pred;
    
    typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
    
    typedef int (*regex_match_func)(char *str, struct regex *r, int len);
    
    
    	MATCH_FRONT_ONLY,
    	MATCH_MIDDLE_ONLY,
    	MATCH_END_ONLY,
    };
    
    
    struct regex {
    	char			pattern[MAX_FILTER_STR_VAL];
    	int			len;
    	int			field_len;
    	regex_match_func	match;
    };
    
    
    struct filter_pred {
    
    	filter_pred_fn_t 	fn;
    	u64 			val;
    	struct regex		regex;
    
    	/*
    	 * Leaf nodes use field_name, ops is used by AND and OR
    	 * nodes. The field_name is always freed when freeing a pred.
    	 * We can overload field_name for ops and have it freed
    	 * as well.
    	 */
    	union {
    		char		*field_name;
    		unsigned short	*ops;
    	};
    
    	unsigned short		index;
    	unsigned short		parent;
    	unsigned short		left;
    	unsigned short		right;
    
    extern struct list_head ftrace_common_fields;
    
    
    extern enum regex_type
    filter_parse_regex(char *buff, int len, char **search, int *not);
    
    extern void print_event_filter(struct ftrace_event_call *call,
    
    extern int apply_event_filter(struct ftrace_event_call *call,
    			      char *filter_string);
    extern int apply_subsystem_event_filter(struct event_subsystem *system,
    					char *filter_string);
    extern void print_subsystem_event_filter(struct event_subsystem *system,
    
    extern int filter_assign_type(const char *type);
    
    struct list_head *
    trace_get_fields(struct ftrace_event_call *event_call);
    
    
    filter_check_discard(struct ftrace_event_call *call, void *rec,
    
    	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
    
    	    !filter_match_preds(call->filter, rec)) {
    
    		ring_buffer_discard_commit(buffer, event);
    		return 1;
    	}
    
    	return 0;
    
    extern void trace_event_enable_cmd_record(bool enable);
    
    
    extern struct mutex event_mutex;
    
    extern struct list_head ftrace_events;
    
    extern const char *__start___trace_bprintk_fmt[];
    extern const char *__stop___trace_bprintk_fmt[];
    
    
    #undef FTRACE_ENTRY
    #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)		\
    
    	extern struct ftrace_event_call					\
    	__attribute__((__aligned__(4))) event_##call;
    
    #undef FTRACE_ENTRY_DUP
    #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)		\
    	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
    #include "trace_entries.h"
    
    /* Only current can touch trace_recursion */
    #define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
    #define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
    
    /* Ring buffer has the 10 LSB bits to count */
    #define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
    
    /* for function tracing recursion */
    #define TRACE_INTERNAL_BIT		(1<<11)
    #define TRACE_GLOBAL_BIT		(1<<12)
    
    #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (bit); } while (0)
    #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(bit); } while (0)
    #define trace_recursion_test(bit)	((current)->trace_recursion & (bit))
    
    
    #endif /* _LINUX_KERNEL_TRACE_H */