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26 results

cls_api.c

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    • Cong Wang's avatar
      1697c4bb
      net_sched: carefully handle tcf_block_put() · 1697c4bb
      Cong Wang authored
      
      As pointed out by Jiri, there is still a race condition between
      tcf_block_put() and tcf_chain_destroy() in a RCU callback. There
      is no way to make it correct without proper locking or synchronization,
      because both operate on a shared list.
      
      Locking is hard, because the only lock we can pick here is a spinlock,
      however, in tc_dump_tfilter() we iterate this list with a sleeping
      function called (tcf_chain_dump()), which makes using a lock to protect
      chain_list almost impossible.
      
      Jiri suggested the idea of holding a refcnt before flushing, this works
      because it guarantees us there would be no parallel tcf_chain_destroy()
      during the loop, therefore the race condition is gone. But we have to
      be very careful with proper synchronization with RCU callbacks.
      
      Suggested-by: default avatarJiri Pirko <jiri@mellanox.com>
      Cc: Jamal Hadi Salim <jhs@mojatatu.com>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1697c4bb
      History
      net_sched: carefully handle tcf_block_put()
      Cong Wang authored
      
      As pointed out by Jiri, there is still a race condition between
      tcf_block_put() and tcf_chain_destroy() in a RCU callback. There
      is no way to make it correct without proper locking or synchronization,
      because both operate on a shared list.
      
      Locking is hard, because the only lock we can pick here is a spinlock,
      however, in tc_dump_tfilter() we iterate this list with a sleeping
      function called (tcf_chain_dump()), which makes using a lock to protect
      chain_list almost impossible.
      
      Jiri suggested the idea of holding a refcnt before flushing, this works
      because it guarantees us there would be no parallel tcf_chain_destroy()
      during the loop, therefore the race condition is gone. But we have to
      be very careful with proper synchronization with RCU callbacks.
      
      Suggested-by: default avatarJiri Pirko <jiri@mellanox.com>
      Cc: Jamal Hadi Salim <jhs@mojatatu.com>
      Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    trace.h 62.52 KiB
    // SPDX-License-Identifier: GPL-2.0
    
    #ifndef _LINUX_KERNEL_TRACE_H
    #define _LINUX_KERNEL_TRACE_H
    
    #include <linux/fs.h>
    #include <linux/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/hw_breakpoint.h>
    #include <linux/trace_seq.h>
    #include <linux/trace_events.h>
    #include <linux/compiler.h>
    #include <linux/glob.h>
    
    #ifdef CONFIG_FTRACE_SYSCALLS
    #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
    #include <asm/syscall.h>	/* some archs define it here */
    #endif
    
    enum trace_type {
    	__TRACE_FIRST_TYPE = 0,
    
    	TRACE_FN,
    	TRACE_CTX,
    	TRACE_WAKE,
    	TRACE_STACK,
    	TRACE_PRINT,
    	TRACE_BPRINT,
    	TRACE_MMIO_RW,
    	TRACE_MMIO_MAP,
    	TRACE_BRANCH,
    	TRACE_GRAPH_RET,
    	TRACE_GRAPH_ENT,
    	TRACE_USER_STACK,
    	TRACE_BLK,
    	TRACE_BPUTS,
    	TRACE_HWLAT,
    	TRACE_RAW_DATA,
    
    	__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, filter)	\
    	struct struct_name {						\
    		struct trace_entry	ent;				\
    		tstruct							\
    	}
    
    #undef FTRACE_ENTRY_DUP
    #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
    
    #undef FTRACE_ENTRY_REG
    #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
    			 filter, regfn) \
    	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
    		     filter)
    
    #undef FTRACE_ENTRY_PACKED
    #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
    			    filter)					\
    	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
    		     filter) __packed
    
    #include "trace_entries.h"
    
    /*
     * 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;
    	long			ret;
    };
    
    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
     *  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,
    	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
    	TRACE_FLAG_NMI			= 0x40,
    };
    
    #define TRACE_BUF_SIZE		1024
    
    struct trace_array;
    
    /*
     * 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		entries;
    	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;
    	u64			preempt_timestamp;
    	pid_t			pid;
    	kuid_t			uid;
    	char			comm[TASK_COMM_LEN];
    
    	bool			ignore_pid;
    #ifdef CONFIG_FUNCTION_TRACER
    	bool			ftrace_ignore_pid;
    #endif
    };
    
    struct tracer;
    struct trace_option_dentry;
    
    struct trace_buffer {
    	struct trace_array		*tr;
    	struct ring_buffer		*buffer;
    	struct trace_array_cpu __percpu	*data;
    	u64				time_start;
    	int				cpu;
    };
    
    #define TRACE_FLAGS_MAX_SIZE		32
    
    struct trace_options {
    	struct tracer			*tracer;
    	struct trace_option_dentry	*topts;
    };
    
    struct trace_pid_list {
    	int				pid_max;
    	unsigned long			*pids;
    };
    
    typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
    
    /**
     * struct cond_snapshot - conditional snapshot data and callback
     *
     * The cond_snapshot structure encapsulates a callback function and
     * data associated with the snapshot for a given tracing instance.
     *
     * When a snapshot is taken conditionally, by invoking
     * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
     * passed in turn to the cond_snapshot.update() function.  That data
     * can be compared by the update() implementation with the cond_data
     * contained wihin the struct cond_snapshot instance associated with
     * the trace_array.  Because the tr->max_lock is held throughout the
     * update() call, the update() function can directly retrieve the
     * cond_snapshot and cond_data associated with the per-instance
     * snapshot associated with the trace_array.
     *
     * The cond_snapshot.update() implementation can save data to be
     * associated with the snapshot if it decides to, and returns 'true'
     * in that case, or it returns 'false' if the conditional snapshot
     * shouldn't be taken.
     *
     * The cond_snapshot instance is created and associated with the
     * user-defined cond_data by tracing_cond_snapshot_enable().
     * Likewise, the cond_snapshot instance is destroyed and is no longer
     * associated with the trace instance by
     * tracing_cond_snapshot_disable().
     *
     * The method below is required.
     *
     * @update: When a conditional snapshot is invoked, the update()
     *	callback function is invoked with the tr->max_lock held.  The
     *	update() implementation signals whether or not to actually
     *	take the snapshot, by returning 'true' if so, 'false' if no
     *	snapshot should be taken.  Because the max_lock is held for
     *	the duration of update(), the implementation is safe to
     *	directly retrieven and save any implementation data it needs
     *	to in association with the snapshot.
     */
    struct cond_snapshot {
    	void				*cond_data;
    	cond_update_fn_t		update;
    };
    
    /*
     * 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 list_head	list;
    	char			*name;
    	struct trace_buffer	trace_buffer;
    #ifdef CONFIG_TRACER_MAX_TRACE
    	/*
    	 * The max_buffer is used to snapshot the trace when a maximum
    	 * latency is reached, or when the user initiates a snapshot.
    	 * Some tracers will use this to store a maximum trace while
    	 * it continues examining live traces.
    	 *
    	 * The buffers for the max_buffer are set up the same as the trace_buffer
    	 * When a snapshot is taken, the buffer of the max_buffer is swapped
    	 * with the buffer of the trace_buffer and the buffers are reset for
    	 * the trace_buffer so the tracing can continue.
    	 */
    	struct trace_buffer	max_buffer;
    	bool			allocated_snapshot;
    #endif
    #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
    	unsigned long		max_latency;
    #endif
    	struct trace_pid_list	__rcu *filtered_pids;
    	/*
    	 * max_lock is used to protect the swapping of buffers
    	 * when taking a max snapshot. The buffers themselves are
    	 * protected by per_cpu spinlocks. But the action of the swap
    	 * needs its own lock.
    	 *
    	 * This is defined as a arch_spinlock_t in order to help
    	 * with performance when lockdep debugging is enabled.
    	 *
    	 * It is also used in other places outside the update_max_tr
    	 * so it needs to be defined outside of the
    	 * CONFIG_TRACER_MAX_TRACE.
    	 */
    	arch_spinlock_t		max_lock;
    	int			buffer_disabled;
    #ifdef CONFIG_FTRACE_SYSCALLS
    	int			sys_refcount_enter;
    	int			sys_refcount_exit;
    	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
    	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
    #endif
    	int			stop_count;
    	int			clock_id;
    	int			nr_topts;
    	bool			clear_trace;
    	int			buffer_percent;
    	unsigned int		n_err_log_entries;
    	struct tracer		*current_trace;
    	unsigned int		trace_flags;
    	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
    	unsigned int		flags;
    	raw_spinlock_t		start_lock;
    	struct list_head	err_log;
    	struct dentry		*dir;
    	struct dentry		*options;
    	struct dentry		*percpu_dir;
    	struct dentry		*event_dir;
    	struct trace_options	*topts;
    	struct list_head	systems;
    	struct list_head	events;
    	struct trace_event_file *trace_marker_file;
    	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
    	int			ref;
    #ifdef CONFIG_FUNCTION_TRACER
    	struct ftrace_ops	*ops;
    	struct trace_pid_list	__rcu *function_pids;
    #ifdef CONFIG_DYNAMIC_FTRACE
    	/* All of these are protected by the ftrace_lock */
    	struct list_head	func_probes;
    	struct list_head	mod_trace;
    	struct list_head	mod_notrace;
    #endif
    	/* function tracing enabled */
    	int			function_enabled;
    #endif
    	int			time_stamp_abs_ref;
    	struct list_head	hist_vars;
    #ifdef CONFIG_TRACER_SNAPSHOT
    	struct cond_snapshot	*cond_snapshot;
    #endif
    };
    
    enum {
    	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
    };
    
    extern struct list_head ftrace_trace_arrays;
    
    extern struct mutex trace_types_lock;
    
    extern int trace_array_get(struct trace_array *tr);
    extern void trace_array_put(struct trace_array *tr);
    
    extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
    extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
    
    extern bool trace_clock_in_ns(struct trace_array *tr);
    
    /*
     * The global tracer (top) should be the first trace array added,
     * but we check the flag anyway.
     */
    static inline struct trace_array *top_trace_array(void)
    {
    	struct trace_array *tr;
    
    	if (list_empty(&ftrace_trace_arrays))
    		return NULL;
    
    	tr = list_entry(ftrace_trace_arrays.prev,
    			typeof(*tr), list);
    	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
    	return tr;
    }
    
    #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 != 0 && (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 bputs_entry, TRACE_BPUTS);	\
    		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
    		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
    		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;
    	struct tracer		*trace;
    };
    
    /* Makes more easy to define a tracer opt */
    #define TRACER_OPT(s, b)	.name = #s, .bit = b
    
    
    struct trace_option_dentry {
    	struct tracer_opt		*opt;
    	struct tracer_flags		*flags;
    	struct trace_array		*tr;
    	struct dentry			*entry;
    };
    
    /**
     * struct tracer - a specific tracer and its callbacks to interact with tracefs
     * @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_on)
     * @stop: called when tracing is paused (echo 0 > tracing_on)
     * @update_thresh: called when tracing_thresh is updated
     * @open: called when the trace file is opened
     * @pipe_open: called when the trace_pipe file is opened
     * @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);
    	int			(*update_thresh)(struct trace_array *tr);
    	void			(*open)(struct trace_iterator *iter);
    	void			(*pipe_open)(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);
    #ifdef CONFIG_FTRACE_STARTUP_TEST
    	int			(*selftest)(struct tracer *trace,
    					    struct trace_array *tr);
    #endif
    	void			(*print_header)(struct seq_file *m);
    	enum print_line_t	(*print_line)(struct trace_iterator *iter);
    	/* If you handled the flag setting, return 0 */
    	int			(*set_flag)(struct trace_array *tr,
    					    u32 old_flags, u32 bit, int set);
    	/* Return 0 if OK with change, else return non-zero */
    	int			(*flag_changed)(struct trace_array *tr,
    						u32 mask, int set);
    	struct tracer		*next;
    	struct tracer_flags	*flags;
    	int			enabled;
    	int			ref;
    	bool			print_max;
    	bool			allow_instances;
    #ifdef CONFIG_TRACER_MAX_TRACE
    	bool			use_max_tr;
    #endif
    	/* True if tracer cannot be enabled in kernel param */
    	bool			noboot;
    };
    
    
    /* Only current can touch trace_recursion */
    
    /*
     * For function tracing recursion:
     *  The order of these bits are important.
     *
     *  When function tracing occurs, the following steps are made:
     *   If arch does not support a ftrace feature:
     *    call internal function (uses INTERNAL bits) which calls...
     *   If callback is registered to the "global" list, the list
     *    function is called and recursion checks the GLOBAL bits.
     *    then this function calls...
     *   The function callback, which can use the FTRACE bits to
     *    check for recursion.
     *
     * Now if the arch does not suppport a feature, and it calls
     * the global list function which calls the ftrace callback
     * all three of these steps will do a recursion protection.
     * There's no reason to do one if the previous caller already
     * did. The recursion that we are protecting against will
     * go through the same steps again.
     *
     * To prevent the multiple recursion checks, if a recursion
     * bit is set that is higher than the MAX bit of the current
     * check, then we know that the check was made by the previous
     * caller, and we can skip the current check.
     */
    enum {
    	TRACE_BUFFER_BIT,
    	TRACE_BUFFER_NMI_BIT,
    	TRACE_BUFFER_IRQ_BIT,
    	TRACE_BUFFER_SIRQ_BIT,
    
    	/* Start of function recursion bits */
    	TRACE_FTRACE_BIT,
    	TRACE_FTRACE_NMI_BIT,
    	TRACE_FTRACE_IRQ_BIT,
    	TRACE_FTRACE_SIRQ_BIT,
    
    	/* INTERNAL_BITs must be greater than FTRACE_BITs */
    	TRACE_INTERNAL_BIT,
    	TRACE_INTERNAL_NMI_BIT,
    	TRACE_INTERNAL_IRQ_BIT,
    	TRACE_INTERNAL_SIRQ_BIT,
    
    	TRACE_BRANCH_BIT,
    /*
     * Abuse of the trace_recursion.
     * As we need a way to maintain state if we are tracing the function
     * graph in irq because we want to trace a particular function that
     * was called in irq context but we have irq tracing off. Since this
     * can only be modified by current, we can reuse trace_recursion.
     */
    	TRACE_IRQ_BIT,
    
    	/* Set if the function is in the set_graph_function file */
    	TRACE_GRAPH_BIT,
    
    	/*
    	 * In the very unlikely case that an interrupt came in
    	 * at a start of graph tracing, and we want to trace
    	 * the function in that interrupt, the depth can be greater
    	 * than zero, because of the preempted start of a previous
    	 * trace. In an even more unlikely case, depth could be 2
    	 * if a softirq interrupted the start of graph tracing,
    	 * followed by an interrupt preempting a start of graph
    	 * tracing in the softirq, and depth can even be 3
    	 * if an NMI came in at the start of an interrupt function
    	 * that preempted a softirq start of a function that
    	 * preempted normal context!!!! Luckily, it can't be
    	 * greater than 3, so the next two bits are a mask
    	 * of what the depth is when we set TRACE_GRAPH_BIT
    	 */
    
    	TRACE_GRAPH_DEPTH_START_BIT,
    	TRACE_GRAPH_DEPTH_END_BIT,
    
    	/*
    	 * To implement set_graph_notrace, if this bit is set, we ignore
    	 * function graph tracing of called functions, until the return
    	 * function is called to clear it.
    	 */
    	TRACE_GRAPH_NOTRACE_BIT,
    };
    
    #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
    #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
    #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
    
    #define trace_recursion_depth() \
    	(((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
    #define trace_recursion_set_depth(depth) \
    	do {								\
    		current->trace_recursion &=				\
    			~(3 << TRACE_GRAPH_DEPTH_START_BIT);		\
    		current->trace_recursion |=				\
    			((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT;	\
    	} while (0)
    
    #define TRACE_CONTEXT_BITS	4
    
    #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
    #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
    
    #define TRACE_LIST_START	TRACE_INTERNAL_BIT
    #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
    
    #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
    
    static __always_inline int trace_get_context_bit(void)
    {
    	int bit;
    
    	if (in_interrupt()) {
    		if (in_nmi())
    			bit = 0;
    
    		else if (in_irq())
    			bit = 1;
    		else
    			bit = 2;
    	} else
    		bit = 3;
    
    	return bit;
    }
    
    static __always_inline int trace_test_and_set_recursion(int start, int max)
    {
    	unsigned int val = current->trace_recursion;
    	int bit;
    
    	/* A previous recursion check was made */
    	if ((val & TRACE_CONTEXT_MASK) > max)
    		return 0;
    
    	bit = trace_get_context_bit() + start;
    	if (unlikely(val & (1 << bit)))
    		return -1;
    
    	val |= 1 << bit;
    	current->trace_recursion = val;
    	barrier();
    
    	return bit;
    }
    
    static __always_inline void trace_clear_recursion(int bit)
    {
    	unsigned int val = current->trace_recursion;
    
    	if (!bit)
    		return;
    
    	bit = 1 << bit;
    	val &= ~bit;
    
    	barrier();
    	current->trace_recursion = val;
    }
    
    static inline struct ring_buffer_iter *
    trace_buffer_iter(struct trace_iterator *iter, int cpu)
    {
    	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
    }
    
    int tracer_init(struct tracer *t, struct trace_array *tr);
    int tracing_is_enabled(void);
    void tracing_reset_online_cpus(struct trace_buffer *buf);
    void tracing_reset_current(int cpu);
    void tracing_reset_all_online_cpus(void);
    int tracing_open_generic(struct inode *inode, struct file *filp);
    bool tracing_is_disabled(void);
    bool tracer_tracing_is_on(struct trace_array *tr);
    void tracer_tracing_on(struct trace_array *tr);
    void tracer_tracing_off(struct trace_array *tr);
    struct dentry *trace_create_file(const char *name,
    				 umode_t mode,
    				 struct dentry *parent,
    				 void *data,
    				 const struct file_operations *fops);
    
    struct dentry *tracing_init_dentry(void);
    
    struct ring_buffer_event;
    
    struct ring_buffer_event *
    trace_buffer_lock_reserve(struct ring_buffer *buffer,
    			  int type,
    			  unsigned long len,
    			  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);
    
    void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
    					struct ring_buffer_event *event);
    
    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);
    
    unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
    unsigned long trace_total_entries(struct trace_array *tr);
    
    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_latency_header(struct seq_file *m);
    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 set_graph_array(struct trace_array *tr);
    
    void tracing_start_cmdline_record(void);
    void tracing_stop_cmdline_record(void);
    void tracing_start_tgid_record(void);
    void tracing_stop_tgid_record(void);
    
    int register_tracer(struct tracer *type);
    int is_tracing_stopped(void);
    
    loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
    
    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;
    
    /* PID filtering */
    
    extern int pid_max;
    
    bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
    			     pid_t search_pid);
    bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
    			    struct task_struct *task);
    void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
    				  struct task_struct *self,
    				  struct task_struct *task);
    void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
    void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
    int trace_pid_show(struct seq_file *m, void *v);
    void trace_free_pid_list(struct trace_pid_list *pid_list);
    int trace_pid_write(struct trace_pid_list *filtered_pids,
    		    struct trace_pid_list **new_pid_list,
    		    const char __user *ubuf, size_t cnt);
    
    #ifdef CONFIG_TRACER_MAX_TRACE
    void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
    		   void *cond_data);
    void update_max_tr_single(struct trace_array *tr,
    			  struct task_struct *tsk, int cpu);
    #endif /* CONFIG_TRACER_MAX_TRACE */
    
    #ifdef CONFIG_STACKTRACE
    void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
    		   int pc);
    #else
    static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
    				 int skip, int pc)
    {
    }
    #endif /* CONFIG_STACKTRACE */
    
    extern u64 ftrace_now(int cpu);
    
    extern void trace_find_cmdline(int pid, char comm[]);
    extern int trace_find_tgid(int pid);
    extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
    
    #ifdef CONFIG_DYNAMIC_FTRACE
    extern unsigned long ftrace_update_tot_cnt;
    void ftrace_init_trace_array(struct trace_array *tr);
    #else
    static inline void ftrace_init_trace_array(struct trace_array *tr) { }
    #endif
    #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 bool ring_buffer_expanded;
    extern bool tracing_selftest_disabled;
    
    #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);
    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);
    extern int trace_selftest_startup_nop(struct tracer *trace,
    					 struct trace_array *tr);
    extern int trace_selftest_startup_branch(struct tracer *trace,
    					 struct trace_array *tr);
    /*
     * Tracer data references selftest functions that only occur
     * on boot up. These can be __init functions. Thus, when selftests
     * are enabled, then the tracers need to reference __init functions.
     */
    #define __tracer_data		__refdata
    #else
    /* Tracers are seldom changed. Optimize when selftests are disabled. */
    #define __tracer_data		__read_mostly
    #endif /* CONFIG_FTRACE_STARTUP_TEST */
    
    extern void *head_page(struct trace_array_cpu *data);
    extern unsigned long long ns2usecs(u64 nsec);
    extern int
    trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
    extern int
    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, ...);
    int trace_array_printk_buf(struct ring_buffer *buffer,
    			   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);
    
    extern char trace_find_mark(unsigned long long duration);
    
    struct ftrace_hash;
    
    struct ftrace_mod_load {
    	struct list_head	list;
    	char			*func;
    	char			*module;
    	int			 enable;
    };
    
    enum {
    	FTRACE_HASH_FL_MOD	= (1 << 0),
    };
    
    struct ftrace_hash {
    	unsigned long		size_bits;
    	struct hlist_head	*buckets;
    	unsigned long		count;
    	unsigned long		flags;
    	struct rcu_head		rcu;
    };
    
    struct ftrace_func_entry *
    ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
    
    static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
    {
    	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
    }
    
    /* Standard output formatting function used for function return traces */
    #ifdef CONFIG_FUNCTION_GRAPH_TRACER
    
    /* 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
    #define TRACE_GRAPH_PRINT_REL_TIME      0x40
    #define TRACE_GRAPH_PRINT_IRQS          0x80
    #define TRACE_GRAPH_PRINT_TAIL          0x100
    #define TRACE_GRAPH_SLEEP_TIME          0x200
    #define TRACE_GRAPH_GRAPH_TIME          0x400
    #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
    #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
    
    extern void ftrace_graph_sleep_time_control(bool enable);
    
    #ifdef CONFIG_FUNCTION_PROFILER
    extern void ftrace_graph_graph_time_control(bool enable);
    #else
    static inline void ftrace_graph_graph_time_control(bool enable) { }
    #endif
    
    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 void
    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
    extern struct ftrace_hash *ftrace_graph_hash;
    extern struct ftrace_hash *ftrace_graph_notrace_hash;
    
    static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
    {
    	unsigned long addr = trace->func;
    	int ret = 0;
    
    	preempt_disable_notrace();
    
    	if (ftrace_hash_empty(ftrace_graph_hash)) {
    		ret = 1;
    		goto out;
    	}
    
    	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
    
    		/*
    		 * This needs to be cleared on the return functions
    		 * when the depth is zero.
    		 */
    		trace_recursion_set(TRACE_GRAPH_BIT);
    		trace_recursion_set_depth(trace->depth);
    
    		/*
    		 * If no irqs are to be traced, but a set_graph_function
    		 * is set, and called by an interrupt handler, we still
    		 * want to trace it.
    		 */
    		if (in_irq())
    			trace_recursion_set(TRACE_IRQ_BIT);
    		else
    			trace_recursion_clear(TRACE_IRQ_BIT);
    		ret = 1;
    	}
    
    out:
    	preempt_enable_notrace();
    	return ret;
    }
    
    static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
    {
    	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
    	    trace->depth == trace_recursion_depth())
    		trace_recursion_clear(TRACE_GRAPH_BIT);
    }
    
    static inline int ftrace_graph_notrace_addr(unsigned long addr)
    {
    	int ret = 0;
    
    	preempt_disable_notrace();
    
    	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
    		ret = 1;
    
    	preempt_enable_notrace();
    	return ret;
    }
    #else
    static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
    {
    	return 1;
    }
    
    static inline int ftrace_graph_notrace_addr(unsigned long addr)
    {
    	return 0;
    }
    static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
    { }
    #endif /* CONFIG_DYNAMIC_FTRACE */
    
    extern unsigned int fgraph_max_depth;
    
    static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
    {
    	/* trace it when it is-nested-in or is a function enabled. */
    	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
    		 ftrace_graph_addr(trace)) ||
    		(trace->depth < 0) ||
    		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
    }
    
    #else /* CONFIG_FUNCTION_GRAPH_TRACER */
    static inline enum print_line_t
    print_graph_function_flags(struct trace_iterator *iter, u32 flags)
    {
    	return TRACE_TYPE_UNHANDLED;
    }
    #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
    
    extern struct list_head ftrace_pids;
    
    #ifdef CONFIG_FUNCTION_TRACER
    struct ftrace_func_command {
    	struct list_head	list;
    	char			*name;
    	int			(*func)(struct trace_array *tr,
    					struct ftrace_hash *hash,
    					char *func, char *cmd,
    					char *params, int enable);
    };
    extern bool ftrace_filter_param __initdata;
    static inline int ftrace_trace_task(struct trace_array *tr)
    {
    	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
    }
    extern int ftrace_is_dead(void);
    int ftrace_create_function_files(struct trace_array *tr,
    				 struct dentry *parent);
    void ftrace_destroy_function_files(struct trace_array *tr);
    void ftrace_init_global_array_ops(struct trace_array *tr);
    void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
    void ftrace_reset_array_ops(struct trace_array *tr);
    void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
    void ftrace_init_tracefs_toplevel(struct trace_array *tr,
    				  struct dentry *d_tracer);
    void ftrace_clear_pids(struct trace_array *tr);
    int init_function_trace(void);
    void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
    #else
    static inline int ftrace_trace_task(struct trace_array *tr)
    {
    	return 1;
    }
    static inline int ftrace_is_dead(void) { return 0; }
    static inline int
    ftrace_create_function_files(struct trace_array *tr,
    			     struct dentry *parent)
    {
    	return 0;
    }
    static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
    static inline __init void
    ftrace_init_global_array_ops(struct trace_array *tr) { }
    static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
    static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
    static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
    static inline void ftrace_clear_pids(struct trace_array *tr) { }
    static inline int init_function_trace(void) { return 0; }
    static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
    /* ftace_func_t type is not defined, use macro instead of static inline */
    #define ftrace_init_array_ops(tr, func) do { } while (0)
    #endif /* CONFIG_FUNCTION_TRACER */
    
    #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
    
    struct ftrace_probe_ops {
    	void			(*func)(unsigned long ip,
    					unsigned long parent_ip,
    					struct trace_array *tr,
    					struct ftrace_probe_ops *ops,
    					void *data);
    	int			(*init)(struct ftrace_probe_ops *ops,
    					struct trace_array *tr,
    					unsigned long ip, void *init_data,
    					void **data);
    	void			(*free)(struct ftrace_probe_ops *ops,
    					struct trace_array *tr,
    					unsigned long ip, void *data);
    	int			(*print)(struct seq_file *m,
    					 unsigned long ip,
    					 struct ftrace_probe_ops *ops,
    					 void *data);
    };
    
    struct ftrace_func_mapper;
    typedef int (*ftrace_mapper_func)(void *data);
    
    struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
    void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
    					   unsigned long ip);
    int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
    			       unsigned long ip, void *data);
    void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
    				   unsigned long ip);
    void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
    			     ftrace_mapper_func free_func);
    
    extern int
    register_ftrace_function_probe(char *glob, struct trace_array *tr,
    			       struct ftrace_probe_ops *ops, void *data);
    extern int
    unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
    				      struct ftrace_probe_ops *ops);
    extern void clear_ftrace_function_probes(struct trace_array *tr);
    
    int register_ftrace_command(struct ftrace_func_command *cmd);
    int unregister_ftrace_command(struct ftrace_func_command *cmd);
    
    void ftrace_create_filter_files(struct ftrace_ops *ops,
    				struct dentry *parent);
    void ftrace_destroy_filter_files(struct ftrace_ops *ops);
    #else
    struct ftrace_func_command;
    
    static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
    {
    	return -EINVAL;
    }
    static inline __init int unregister_ftrace_command(char *cmd_name)
    {
    	return -EINVAL;
    }
    static inline void clear_ftrace_function_probes(struct trace_array *tr)
    {
    }
    
    /*
     * The ops parameter passed in is usually undefined.
     * This must be a macro.
     */
    #define ftrace_create_filter_files(ops, parent) do { } while (0)
    #define ftrace_destroy_filter_files(ops) do { } while (0)
    #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
    
    bool ftrace_event_is_function(struct trace_event_call *call);
    
    /*
     * 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);
    
    /*
     * Only create function graph options if function graph is configured.
     */
    #ifdef CONFIG_FUNCTION_GRAPH_TRACER
    # define FGRAPH_FLAGS						\
    		C(DISPLAY_GRAPH,	"display-graph"),
    #else
    # define FGRAPH_FLAGS
    #endif
    
    #ifdef CONFIG_BRANCH_TRACER
    # define BRANCH_FLAGS					\
    		C(BRANCH,		"branch"),
    #else
    # define BRANCH_FLAGS
    #endif
    
    #ifdef CONFIG_FUNCTION_TRACER
    # define FUNCTION_FLAGS						\
    		C(FUNCTION,		"function-trace"),	\
    		C(FUNC_FORK,		"function-fork"),
    # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
    #else
    # define FUNCTION_FLAGS
    # define FUNCTION_DEFAULT_FLAGS		0UL
    # define TRACE_ITER_FUNC_FORK		0UL
    #endif
    
    #ifdef CONFIG_STACKTRACE
    # define STACK_FLAGS				\
    		C(STACKTRACE,		"stacktrace"),
    #else
    # define STACK_FLAGS
    #endif
    
    /*
     * 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 (this macro guarantees it).
     */
    #define TRACE_FLAGS						\
    		C(PRINT_PARENT,		"print-parent"),	\
    		C(SYM_OFFSET,		"sym-offset"),		\
    		C(SYM_ADDR,		"sym-addr"),		\
    		C(VERBOSE,		"verbose"),		\
    		C(RAW,			"raw"),			\
    		C(HEX,			"hex"),			\
    		C(BIN,			"bin"),			\
    		C(BLOCK,		"block"),		\
    		C(PRINTK,		"trace_printk"),	\
    		C(ANNOTATE,		"annotate"),		\
    		C(USERSTACKTRACE,	"userstacktrace"),	\
    		C(SYM_USEROBJ,		"sym-userobj"),		\
    		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
    		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
    		C(LATENCY_FMT,		"latency-format"),	\
    		C(RECORD_CMD,		"record-cmd"),		\
    		C(RECORD_TGID,		"record-tgid"),		\
    		C(OVERWRITE,		"overwrite"),		\
    		C(STOP_ON_FREE,		"disable_on_free"),	\
    		C(IRQ_INFO,		"irq-info"),		\
    		C(MARKERS,		"markers"),		\
    		C(EVENT_FORK,		"event-fork"),		\
    		FUNCTION_FLAGS					\
    		FGRAPH_FLAGS					\
    		STACK_FLAGS					\
    		BRANCH_FLAGS
    
    /*
     * By defining C, we can make TRACE_FLAGS a list of bit names
     * that will define the bits for the flag masks.
     */
    #undef C
    #define C(a, b) TRACE_ITER_##a##_BIT
    
    enum trace_iterator_bits {
    	TRACE_FLAGS
    	/* Make sure we don't go more than we have bits for */
    	TRACE_ITER_LAST_BIT
    };
    
    /*
     * By redefining C, we can make TRACE_FLAGS a list of masks that
     * use the bits as defined above.
     */
    #undef C
    #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
    
    enum trace_iterator_flags { TRACE_FLAGS };
    
    /*
     * 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 (tr->trace_flags & TRACE_ITER_BRANCH)
    		return enable_branch_tracing(tr);
    	return 0;
    }
    static inline void trace_branch_disable(void)
    {
    	/* due to races, always disable */
    	disable_branch_tracing();
    }
    #else
    static inline int trace_branch_enable(struct trace_array *tr)
    {
    	return 0;
    }
    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);
    
    struct ftrace_event_field {
    	struct list_head	link;
    	const char		*name;
    	const char		*type;
    	int			filter_type;
    	int			offset;
    	int			size;
    	int			is_signed;
    };
    
    struct prog_entry;
    
    struct event_filter {
    	struct prog_entry __rcu	*prog;
    	char			*filter_string;
    };
    
    struct event_subsystem {
    	struct list_head	list;
    	const char		*name;
    	struct event_filter	*filter;
    	int			ref_count;
    };
    
    struct trace_subsystem_dir {
    	struct list_head		list;
    	struct event_subsystem		*subsystem;
    	struct trace_array		*tr;
    	struct dentry			*entry;
    	int				ref_count;
    	int				nr_events;
    };
    
    extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
    				     struct ring_buffer *buffer,
    				     struct ring_buffer_event *event);
    
    void trace_buffer_unlock_commit_regs(struct trace_array *tr,
    				     struct ring_buffer *buffer,
    				     struct ring_buffer_event *event,
    				     unsigned long flags, int pc,
    				     struct pt_regs *regs);
    
    static inline void trace_buffer_unlock_commit(struct trace_array *tr,
    					      struct ring_buffer *buffer,
    					      struct ring_buffer_event *event,
    					      unsigned long flags, int pc)
    {
    	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
    }
    
    DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
    DECLARE_PER_CPU(int, trace_buffered_event_cnt);
    void trace_buffered_event_disable(void);
    void trace_buffered_event_enable(void);
    
    static inline void
    __trace_event_discard_commit(struct ring_buffer *buffer,
    			     struct ring_buffer_event *event)
    {
    	if (this_cpu_read(trace_buffered_event) == event) {
    		/* Simply release the temp buffer */
    		this_cpu_dec(trace_buffered_event_cnt);
    		return;
    	}
    	ring_buffer_discard_commit(buffer, event);
    }
    
    /*
     * Helper function for event_trigger_unlock_commit{_regs}().
     * If there are event triggers attached to this event that requires
     * filtering against its fields, then they wil be called as the
     * entry already holds the field information of the current event.
     *
     * It also checks if the event should be discarded or not.
     * It is to be discarded if the event is soft disabled and the
     * event was only recorded to process triggers, or if the event
     * filter is active and this event did not match the filters.
     *
     * Returns true if the event is discarded, false otherwise.
     */
    static inline bool
    __event_trigger_test_discard(struct trace_event_file *file,
    			     struct ring_buffer *buffer,
    			     struct ring_buffer_event *event,
    			     void *entry,
    			     enum event_trigger_type *tt)
    {
    	unsigned long eflags = file->flags;
    
    	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
    		*tt = event_triggers_call(file, entry, event);
    
    	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
    	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
    	     !filter_match_preds(file->filter, entry))) {
    		__trace_event_discard_commit(buffer, event);
    		return true;
    	}
    
    	return false;
    }
    
    /**
     * event_trigger_unlock_commit - handle triggers and finish event commit
     * @file: The file pointer assoctiated to the event
     * @buffer: The ring buffer that the event is being written to
     * @event: The event meta data in the ring buffer
     * @entry: The event itself
     * @irq_flags: The state of the interrupts at the start of the event
     * @pc: The state of the preempt count at the start of the event.
     *
     * This is a helper function to handle triggers that require data
     * from the event itself. It also tests the event against filters and
     * if the event is soft disabled and should be discarded.
     */
    static inline void
    event_trigger_unlock_commit(struct trace_event_file *file,
    			    struct ring_buffer *buffer,
    			    struct ring_buffer_event *event,
    			    void *entry, unsigned long irq_flags, int pc)
    {
    	enum event_trigger_type tt = ETT_NONE;
    
    	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
    		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
    
    	if (tt)
    		event_triggers_post_call(file, tt);
    }
    
    /**
     * event_trigger_unlock_commit_regs - handle triggers and finish event commit
     * @file: The file pointer assoctiated to the event
     * @buffer: The ring buffer that the event is being written to
     * @event: The event meta data in the ring buffer
     * @entry: The event itself
     * @irq_flags: The state of the interrupts at the start of the event
     * @pc: The state of the preempt count at the start of the event.
     *
     * This is a helper function to handle triggers that require data
     * from the event itself. It also tests the event against filters and
     * if the event is soft disabled and should be discarded.
     *
     * Same as event_trigger_unlock_commit() but calls
     * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
     */
    static inline void
    event_trigger_unlock_commit_regs(struct trace_event_file *file,
    				 struct ring_buffer *buffer,
    				 struct ring_buffer_event *event,
    				 void *entry, unsigned long irq_flags, int pc,
    				 struct pt_regs *regs)
    {
    	enum event_trigger_type tt = ETT_NONE;
    
    	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
    		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
    						irq_flags, pc, regs);
    
    	if (tt)
    		event_triggers_post_call(file, tt);
    }
    
    #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;
    struct regex;
    
    typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
    
    typedef int (*regex_match_func)(char *str, struct regex *r, int len);
    
    enum regex_type {
    	MATCH_FULL = 0,
    	MATCH_FRONT_ONLY,
    	MATCH_MIDDLE_ONLY,
    	MATCH_END_ONLY,
    	MATCH_GLOB,
    	MATCH_INDEX,
    };
    
    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;
    	unsigned short		*ops;
    	struct ftrace_event_field *field;
    	int 			offset;
    	int			not;
    	int 			op;
    };
    
    static inline bool is_string_field(struct ftrace_event_field *field)
    {
    	return field->filter_type == FILTER_DYN_STRING ||
    	       field->filter_type == FILTER_STATIC_STRING ||
    	       field->filter_type == FILTER_PTR_STRING ||
    	       field->filter_type == FILTER_COMM;
    }
    
    static inline bool is_function_field(struct ftrace_event_field *field)
    {
    	return field->filter_type == FILTER_TRACE_FN;
    }
    
    extern enum regex_type
    filter_parse_regex(char *buff, int len, char **search, int *not);
    extern void print_event_filter(struct trace_event_file *file,
    			       struct trace_seq *s);
    extern int apply_event_filter(struct trace_event_file *file,
    			      char *filter_string);
    extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
    					char *filter_string);
    extern void print_subsystem_event_filter(struct event_subsystem *system,
    					 struct trace_seq *s);
    extern int filter_assign_type(const char *type);
    extern int create_event_filter(struct trace_array *tr,
    			       struct trace_event_call *call,
    			       char *filter_str, bool set_str,
    			       struct event_filter **filterp);
    extern void free_event_filter(struct event_filter *filter);
    
    struct ftrace_event_field *
    trace_find_event_field(struct trace_event_call *call, char *name);
    
    extern void trace_event_enable_cmd_record(bool enable);
    extern void trace_event_enable_tgid_record(bool enable);
    
    extern int event_trace_init(void);
    extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
    extern int event_trace_del_tracer(struct trace_array *tr);
    
    extern struct trace_event_file *__find_event_file(struct trace_array *tr,
    						  const char *system,
    						  const char *event);
    extern struct trace_event_file *find_event_file(struct trace_array *tr,
    						const char *system,
    						const char *event);
    
    static inline void *event_file_data(struct file *filp)
    {
    	return READ_ONCE(file_inode(filp)->i_private);
    }
    
    extern struct mutex event_mutex;
    extern struct list_head ftrace_events;
    
    extern const struct file_operations event_trigger_fops;
    extern const struct file_operations event_hist_fops;
    
    #ifdef CONFIG_HIST_TRIGGERS
    extern int register_trigger_hist_cmd(void);
    extern int register_trigger_hist_enable_disable_cmds(void);
    #else
    static inline int register_trigger_hist_cmd(void) { return 0; }
    static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
    #endif
    
    extern int register_trigger_cmds(void);
    extern void clear_event_triggers(struct trace_array *tr);
    
    struct event_trigger_data {
    	unsigned long			count;
    	int				ref;
    	struct event_trigger_ops	*ops;
    	struct event_command		*cmd_ops;
    	struct event_filter __rcu	*filter;
    	char				*filter_str;
    	void				*private_data;
    	bool				paused;
    	bool				paused_tmp;
    	struct list_head		list;
    	char				*name;
    	struct list_head		named_list;
    	struct event_trigger_data	*named_data;
    };
    
    /* Avoid typos */
    #define ENABLE_EVENT_STR	"enable_event"
    #define DISABLE_EVENT_STR	"disable_event"
    #define ENABLE_HIST_STR		"enable_hist"
    #define DISABLE_HIST_STR	"disable_hist"
    
    struct enable_trigger_data {
    	struct trace_event_file		*file;
    	bool				enable;
    	bool				hist;
    };
    
    extern int event_enable_trigger_print(struct seq_file *m,
    				      struct event_trigger_ops *ops,
    				      struct event_trigger_data *data);
    extern void event_enable_trigger_free(struct event_trigger_ops *ops,
    				      struct event_trigger_data *data);
    extern int event_enable_trigger_func(struct event_command *cmd_ops,
    				     struct trace_event_file *file,
    				     char *glob, char *cmd, char *param);
    extern int event_enable_register_trigger(char *glob,
    					 struct event_trigger_ops *ops,
    					 struct event_trigger_data *data,
    					 struct trace_event_file *file);
    extern void event_enable_unregister_trigger(char *glob,
    					    struct event_trigger_ops *ops,
    					    struct event_trigger_data *test,
    					    struct trace_event_file *file);
    extern void trigger_data_free(struct event_trigger_data *data);
    extern int event_trigger_init(struct event_trigger_ops *ops,
    			      struct event_trigger_data *data);
    extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
    					      int trigger_enable);
    extern void update_cond_flag(struct trace_event_file *file);
    extern int set_trigger_filter(char *filter_str,
    			      struct event_trigger_data *trigger_data,
    			      struct trace_event_file *file);
    extern struct event_trigger_data *find_named_trigger(const char *name);
    extern bool is_named_trigger(struct event_trigger_data *test);
    extern int save_named_trigger(const char *name,
    			      struct event_trigger_data *data);
    extern void del_named_trigger(struct event_trigger_data *data);
    extern void pause_named_trigger(struct event_trigger_data *data);
    extern void unpause_named_trigger(struct event_trigger_data *data);
    extern void set_named_trigger_data(struct event_trigger_data *data,
    				   struct event_trigger_data *named_data);
    extern struct event_trigger_data *
    get_named_trigger_data(struct event_trigger_data *data);
    extern int register_event_command(struct event_command *cmd);
    extern int unregister_event_command(struct event_command *cmd);
    extern int register_trigger_hist_enable_disable_cmds(void);
    
    /**
     * struct event_trigger_ops - callbacks for trace event triggers
     *
     * The methods in this structure provide per-event trigger hooks for
     * various trigger operations.
     *
     * All the methods below, except for @init() and @free(), must be
     * implemented.
     *
     * @func: The trigger 'probe' function called when the triggering
     *	event occurs.  The data passed into this callback is the data
     *	that was supplied to the event_command @reg() function that
     *	registered the trigger (see struct event_command) along with
     *	the trace record, rec.
     *
     * @init: An optional initialization function called for the trigger
     *	when the trigger is registered (via the event_command reg()
     *	function).  This can be used to perform per-trigger
     *	initialization such as incrementing a per-trigger reference
     *	count, for instance.  This is usually implemented by the
     *	generic utility function @event_trigger_init() (see
     *	trace_event_triggers.c).
     *
     * @free: An optional de-initialization function called for the
     *	trigger when the trigger is unregistered (via the
     *	event_command @reg() function).  This can be used to perform
     *	per-trigger de-initialization such as decrementing a
     *	per-trigger reference count and freeing corresponding trigger
     *	data, for instance.  This is usually implemented by the
     *	generic utility function @event_trigger_free() (see
     *	trace_event_triggers.c).
     *
     * @print: The callback function invoked to have the trigger print
     *	itself.  This is usually implemented by a wrapper function
     *	that calls the generic utility function @event_trigger_print()
     *	(see trace_event_triggers.c).
     */
    struct event_trigger_ops {
    	void			(*func)(struct event_trigger_data *data,
    					void *rec,
    					struct ring_buffer_event *rbe);
    	int			(*init)(struct event_trigger_ops *ops,
    					struct event_trigger_data *data);
    	void			(*free)(struct event_trigger_ops *ops,
    					struct event_trigger_data *data);
    	int			(*print)(struct seq_file *m,
    					 struct event_trigger_ops *ops,
    					 struct event_trigger_data *data);
    };
    
    /**
     * struct event_command - callbacks and data members for event commands
     *
     * Event commands are invoked by users by writing the command name
     * into the 'trigger' file associated with a trace event.  The
     * parameters associated with a specific invocation of an event
     * command are used to create an event trigger instance, which is
     * added to the list of trigger instances associated with that trace
     * event.  When the event is hit, the set of triggers associated with
     * that event is invoked.
     *
     * The data members in this structure provide per-event command data
     * for various event commands.
     *
     * All the data members below, except for @post_trigger, must be set
     * for each event command.
     *
     * @name: The unique name that identifies the event command.  This is
     *	the name used when setting triggers via trigger files.
     *
     * @trigger_type: A unique id that identifies the event command
     *	'type'.  This value has two purposes, the first to ensure that
     *	only one trigger of the same type can be set at a given time
     *	for a particular event e.g. it doesn't make sense to have both
     *	a traceon and traceoff trigger attached to a single event at
     *	the same time, so traceon and traceoff have the same type
     *	though they have different names.  The @trigger_type value is
     *	also used as a bit value for deferring the actual trigger
     *	action until after the current event is finished.  Some
     *	commands need to do this if they themselves log to the trace
     *	buffer (see the @post_trigger() member below).  @trigger_type
     *	values are defined by adding new values to the trigger_type
     *	enum in include/linux/trace_events.h.
     *
     * @flags: See the enum event_command_flags below.
     *
     * All the methods below, except for @set_filter() and @unreg_all(),
     * must be implemented.
     *
     * @func: The callback function responsible for parsing and
     *	registering the trigger written to the 'trigger' file by the
     *	user.  It allocates the trigger instance and registers it with
     *	the appropriate trace event.  It makes use of the other
     *	event_command callback functions to orchestrate this, and is
     *	usually implemented by the generic utility function
     *	@event_trigger_callback() (see trace_event_triggers.c).
     *
     * @reg: Adds the trigger to the list of triggers associated with the
     *	event, and enables the event trigger itself, after
     *	initializing it (via the event_trigger_ops @init() function).
     *	This is also where commands can use the @trigger_type value to
     *	make the decision as to whether or not multiple instances of
     *	the trigger should be allowed.  This is usually implemented by
     *	the generic utility function @register_trigger() (see
     *	trace_event_triggers.c).
     *
     * @unreg: Removes the trigger from the list of triggers associated
     *	with the event, and disables the event trigger itself, after
     *	initializing it (via the event_trigger_ops @free() function).
     *	This is usually implemented by the generic utility function
     *	@unregister_trigger() (see trace_event_triggers.c).
     *
     * @unreg_all: An optional function called to remove all the triggers
     *	from the list of triggers associated with the event.  Called
     *	when a trigger file is opened in truncate mode.
     *
     * @set_filter: An optional function called to parse and set a filter
     *	for the trigger.  If no @set_filter() method is set for the
     *	event command, filters set by the user for the command will be
     *	ignored.  This is usually implemented by the generic utility
     *	function @set_trigger_filter() (see trace_event_triggers.c).
     *
     * @get_trigger_ops: The callback function invoked to retrieve the
     *	event_trigger_ops implementation associated with the command.
     */
    struct event_command {
    	struct list_head	list;
    	char			*name;
    	enum event_trigger_type	trigger_type;
    	int			flags;
    	int			(*func)(struct event_command *cmd_ops,
    					struct trace_event_file *file,
    					char *glob, char *cmd, char *params);
    	int			(*reg)(char *glob,
    				       struct event_trigger_ops *ops,
    				       struct event_trigger_data *data,
    				       struct trace_event_file *file);
    	void			(*unreg)(char *glob,
    					 struct event_trigger_ops *ops,
    					 struct event_trigger_data *data,
    					 struct trace_event_file *file);
    	void			(*unreg_all)(struct trace_event_file *file);
    	int			(*set_filter)(char *filter_str,
    					      struct event_trigger_data *data,
    					      struct trace_event_file *file);
    	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
    };
    
    /**
     * enum event_command_flags - flags for struct event_command
     *
     * @POST_TRIGGER: A flag that says whether or not this command needs
     *	to have its action delayed until after the current event has
     *	been closed.  Some triggers need to avoid being invoked while
     *	an event is currently in the process of being logged, since
     *	the trigger may itself log data into the trace buffer.  Thus
     *	we make sure the current event is committed before invoking
     *	those triggers.  To do that, the trigger invocation is split
     *	in two - the first part checks the filter using the current
     *	trace record; if a command has the @post_trigger flag set, it
     *	sets a bit for itself in the return value, otherwise it
     *	directly invokes the trigger.  Once all commands have been
     *	either invoked or set their return flag, the current record is
     *	either committed or discarded.  At that point, if any commands
     *	have deferred their triggers, those commands are finally
     *	invoked following the close of the current event.  In other
     *	words, if the event_trigger_ops @func() probe implementation
     *	itself logs to the trace buffer, this flag should be set,
     *	otherwise it can be left unspecified.
     *
     * @NEEDS_REC: A flag that says whether or not this command needs
     *	access to the trace record in order to perform its function,
     *	regardless of whether or not it has a filter associated with
     *	it (filters make a trigger require access to the trace record
     *	but are not always present).
     */
    enum event_command_flags {
    	EVENT_CMD_FL_POST_TRIGGER	= 1,
    	EVENT_CMD_FL_NEEDS_REC		= 2,
    };
    
    static inline bool event_command_post_trigger(struct event_command *cmd_ops)
    {
    	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
    }
    
    static inline bool event_command_needs_rec(struct event_command *cmd_ops)
    {
    	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
    }
    
    extern int trace_event_enable_disable(struct trace_event_file *file,
    				      int enable, int soft_disable);
    extern int tracing_alloc_snapshot(void);
    extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
    extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
    
    extern int tracing_snapshot_cond_disable(struct trace_array *tr);
    extern void *tracing_cond_snapshot_data(struct trace_array *tr);
    
    extern const char *__start___trace_bprintk_fmt[];
    extern const char *__stop___trace_bprintk_fmt[];
    
    extern const char *__start___tracepoint_str[];
    extern const char *__stop___tracepoint_str[];
    
    void trace_printk_control(bool enabled);
    void trace_printk_init_buffers(void);
    void trace_printk_start_comm(void);
    int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
    int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
    
    #define MAX_EVENT_NAME_LEN	64
    
    extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
    extern ssize_t trace_parse_run_command(struct file *file,
    		const char __user *buffer, size_t count, loff_t *ppos,
    		int (*createfn)(int, char**));
    
    extern unsigned int err_pos(char *cmd, const char *str);
    extern void tracing_log_err(struct trace_array *tr,
    			    const char *loc, const char *cmd,
    			    const char **errs, u8 type, u8 pos);
    
    /*
     * Normal trace_printk() and friends allocates special buffers
     * to do the manipulation, as well as saves the print formats
     * into sections to display. But the trace infrastructure wants
     * to use these without the added overhead at the price of being
     * a bit slower (used mainly for warnings, where we don't care
     * about performance). The internal_trace_puts() is for such
     * a purpose.
     */
    #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
    
    #undef FTRACE_ENTRY
    #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
    	extern struct trace_event_call					\
    	__aligned(4) event_##call;
    #undef FTRACE_ENTRY_DUP
    #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
    	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
    		     filter)
    #undef FTRACE_ENTRY_PACKED
    #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
    	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
    		     filter)
    
    #include "trace_entries.h"
    
    #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
    int perf_ftrace_event_register(struct trace_event_call *call,
    			       enum trace_reg type, void *data);
    #else
    #define perf_ftrace_event_register NULL
    #endif
    
    #ifdef CONFIG_FTRACE_SYSCALLS
    void init_ftrace_syscalls(void);
    const char *get_syscall_name(int syscall);
    #else
    static inline void init_ftrace_syscalls(void) { }
    static inline const char *get_syscall_name(int syscall)
    {
    	return NULL;
    }
    #endif
    
    #ifdef CONFIG_EVENT_TRACING
    void trace_event_init(void);
    void trace_event_eval_update(struct trace_eval_map **map, int len);
    #else
    static inline void __init trace_event_init(void) { }
    static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
    #endif
    
    #ifdef CONFIG_TRACER_SNAPSHOT
    void tracing_snapshot_instance(struct trace_array *tr);
    int tracing_alloc_snapshot_instance(struct trace_array *tr);
    #else
    static inline void tracing_snapshot_instance(struct trace_array *tr) { }
    static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
    {
    	return 0;
    }
    #endif
    
    #ifdef CONFIG_PREEMPT_TRACER
    void tracer_preempt_on(unsigned long a0, unsigned long a1);
    void tracer_preempt_off(unsigned long a0, unsigned long a1);
    #else
    static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
    static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
    #endif
    #ifdef CONFIG_IRQSOFF_TRACER
    void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
    void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
    #else
    static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
    static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
    #endif
    
    extern struct trace_iterator *tracepoint_print_iter;
    
    /*
     * Reset the state of the trace_iterator so that it can read consumed data.
     * Normally, the trace_iterator is used for reading the data when it is not
     * consumed, and must retain state.
     */
    static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
    {
    	const size_t offset = offsetof(struct trace_iterator, seq);
    
    	/*
    	 * Keep gcc from complaining about overwriting more than just one
    	 * member in the structure.
    	 */
    	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
    
    	iter->pos = -1;
    }
    
    #endif /* _LINUX_KERNEL_TRACE_H */