// SPDX-License-Identifier: GPL-2.0

  /*
   *
   * Function graph tracer.

   * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>

   * Mostly borrowed from function tracer which
   * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
   *
   */

  #include <linux/uaccess.h>
  #include <linux/ftrace.h>

  #include <linux/interrupt.h>

  #include <linux/slab.h>

  #include <linux/fs.h>
  
  #include "trace.h"

  #include "trace_output.h"

  static bool kill_ftrace_graph;
  
  /**
   * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
   *
   * ftrace_graph_stop() is called when a severe error is detected in
   * the function graph tracing. This function is called by the critical
   * paths of function graph to keep those paths from doing any more harm.
   */
  bool ftrace_graph_is_dead(void)
  {
  	return kill_ftrace_graph;
  }
  
  /**
   * ftrace_graph_stop - set to permanently disable function graph tracincg
   *
   * In case of an error int function graph tracing, this is called
   * to try to keep function graph tracing from causing any more harm.
   * Usually this is pretty severe and this is called to try to at least
   * get a warning out to the user.
   */
  void ftrace_graph_stop(void)
  {
  	kill_ftrace_graph = true;

  }

  /* When set, irq functions will be ignored */
  static int ftrace_graph_skip_irqs;

  struct fgraph_cpu_data {

  	pid_t		last_pid;
  	int		depth;

  	int		depth_irq;

  	int		ignore;

  	unsigned long	enter_funcs[FTRACE_RETFUNC_DEPTH];

  };
  
  struct fgraph_data {

  	struct fgraph_cpu_data __percpu *cpu_data;

  
  	/* Place to preserve last processed entry. */
  	struct ftrace_graph_ent_entry	ent;
  	struct ftrace_graph_ret_entry	ret;
  	int				failed;
  	int				cpu;

  };

  #define TRACE_GRAPH_INDENT	2

  unsigned int fgraph_max_depth;

  static struct tracer_opt trace_opts[] = {

  	/* Display overruns? (for self-debug purpose) */

  	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
  	/* Display CPU ? */
  	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
  	/* Display Overhead ? */
  	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },

  	/* Display proc name/pid */
  	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },

  	/* Display duration of execution */
  	{ TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
  	/* Display absolute time of an entry */
  	{ TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },

  	/* Display interrupts */
  	{ TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },

  	/* Display function name after trailing } */
  	{ TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },

  	/* Include sleep time (scheduled out) between entry and return */
  	{ TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) },
  	/* Include time within nested functions */
  	{ TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) },

  	{ } /* Empty entry */
  };
  
  static struct tracer_flags tracer_flags = {

  	/* Don't display overruns, proc, or tail by default */

  	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |

  	       TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS |
  	       TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME,

  	.opts = trace_opts
  };

  static struct trace_array *graph_array;

  /*
   * DURATION column is being also used to display IRQ signs,
   * following values are used by print_graph_irq and others
   * to fill in space into DURATION column.
   */
  enum {

  	FLAGS_FILL_FULL  = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
  	FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
  	FLAGS_FILL_END   = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,

  };

  static void

  print_graph_duration(struct trace_array *tr, unsigned long long duration,
  		     struct trace_seq *s, u32 flags);

  /* Add a function return address to the trace stack on thread info.*/

  static int

  ftrace_push_return_trace(unsigned long ret, unsigned long func,

  			 unsigned long frame_pointer, unsigned long *retp)

  {

  	unsigned long long calltime;

  	int index;

  	if (unlikely(ftrace_graph_is_dead()))
  		return -EBUSY;

  	if (!current->ret_stack)
  		return -EBUSY;

  	/*
  	 * We must make sure the ret_stack is tested before we read
  	 * anything else.
  	 */
  	smp_rmb();

  	/* The return trace stack is full */
  	if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
  		atomic_inc(&current->trace_overrun);
  		return -EBUSY;
  	}

  	/*
  	 * The curr_ret_stack is an index to ftrace return stack of
  	 * current task.  Its value should be in [0, FTRACE_RETFUNC_
  	 * DEPTH) when the function graph tracer is used.  To support
  	 * filtering out specific functions, it makes the index
  	 * negative by subtracting huge value (FTRACE_NOTRACE_DEPTH)
  	 * so when it sees a negative index the ftrace will ignore
  	 * the record.  And the index gets recovered when returning
  	 * from the filtered function by adding the FTRACE_NOTRACE_
  	 * DEPTH and then it'll continue to record functions normally.
  	 *
  	 * The curr_ret_stack is initialized to -1 and get increased
  	 * in this function.  So it can be less than -1 only if it was
  	 * filtered out via ftrace_graph_notrace_addr() which can be

  	 * set from set_graph_notrace file in tracefs by user.

  	 */
  	if (current->curr_ret_stack < -1)
  		return -EBUSY;

  	calltime = trace_clock_local();

  	index = ++current->curr_ret_stack;

  	if (ftrace_graph_notrace_addr(func))
  		current->curr_ret_stack -= FTRACE_NOTRACE_DEPTH;

  	barrier();
  	current->ret_stack[index].ret = ret;
  	current->ret_stack[index].func = func;

  	current->ret_stack[index].calltime = calltime;

  #ifdef HAVE_FUNCTION_GRAPH_FP_TEST

  	current->ret_stack[index].fp = frame_pointer;

  #endif

  #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  	current->ret_stack[index].retp = retp;
  #endif

  	return 0;
  }

  int function_graph_enter(unsigned long ret, unsigned long func,
  			 unsigned long frame_pointer, unsigned long *retp)
  {
  	struct ftrace_graph_ent trace;
  
  	trace.func = func;

  	trace.depth = ++current->curr_ret_depth;

  	if (ftrace_push_return_trace(ret, func,
  				     frame_pointer, retp))
  		goto out;

  	/* Only trace if the calling function expects to */
  	if (!ftrace_graph_entry(&trace))
  		goto out_ret;

  	return 0;

   out_ret:
  	current->curr_ret_stack--;

   out:
  	current->curr_ret_depth--;
  	return -EBUSY;

  }

  /* Retrieve a function return address to the trace stack on thread info.*/

  static void

  ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
  			unsigned long frame_pointer)

  {
  	int index;
  
  	index = current->curr_ret_stack;

  	/*
  	 * A negative index here means that it's just returned from a
  	 * notrace'd function.  Recover index to get an original
  	 * return address.  See ftrace_push_return_trace().
  	 *
  	 * TODO: Need to check whether the stack gets corrupted.
  	 */
  	if (index < 0)
  		index += FTRACE_NOTRACE_DEPTH;
  
  	if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) {

  		ftrace_graph_stop();
  		WARN_ON(1);
  		/* Might as well panic, otherwise we have no where to go */
  		*ret = (unsigned long)panic;
  		return;
  	}

  #ifdef HAVE_FUNCTION_GRAPH_FP_TEST

  	/*
  	 * The arch may choose to record the frame pointer used
  	 * and check it here to make sure that it is what we expect it
  	 * to be. If gcc does not set the place holder of the return
  	 * address in the frame pointer, and does a copy instead, then
  	 * the function graph trace will fail. This test detects this
  	 * case.
  	 *
  	 * Currently, x86_32 with optimize for size (-Os) makes the latest
  	 * gcc do the above.

  	 *
  	 * Note, -mfentry does not use frame pointers, and this test
  	 *  is not needed if CC_USING_FENTRY is set.

  	 */
  	if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
  		ftrace_graph_stop();
  		WARN(1, "Bad frame pointer: expected %lx, received %lx
  "

  		     "  from func %ps return to %lx
  ",

  		     current->ret_stack[index].fp,
  		     frame_pointer,
  		     (void *)current->ret_stack[index].func,
  		     current->ret_stack[index].ret);
  		*ret = (unsigned long)panic;
  		return;
  	}
  #endif

  	*ret = current->ret_stack[index].ret;
  	trace->func = current->ret_stack[index].func;
  	trace->calltime = current->ret_stack[index].calltime;
  	trace->overrun = atomic_read(&current->trace_overrun);

  	trace->depth = current->curr_ret_depth--;
  	/*
  	 * We still want to trace interrupts coming in if
  	 * max_depth is set to 1. Make sure the decrement is
  	 * seen before ftrace_graph_return.
  	 */
  	barrier();

  }
  
  /*
   * Send the trace to the ring-buffer.
   * @return the original return address.
   */

  unsigned long ftrace_return_to_handler(unsigned long frame_pointer)

  {
  	struct ftrace_graph_ret trace;
  	unsigned long ret;

  	ftrace_pop_return_trace(&trace, &ret, frame_pointer);

  	trace.rettime = trace_clock_local();

  	ftrace_graph_return(&trace);
  	/*
  	 * The ftrace_graph_return() may still access the current
  	 * ret_stack structure, we need to make sure the update of
  	 * curr_ret_stack is after that.
  	 */

  	barrier();
  	current->curr_ret_stack--;

  	/*
  	 * The curr_ret_stack can be less than -1 only if it was
  	 * filtered out and it's about to return from the function.
  	 * Recover the index and continue to trace normal functions.
  	 */
  	if (current->curr_ret_stack < -1) {
  		current->curr_ret_stack += FTRACE_NOTRACE_DEPTH;
  		return ret;
  	}

  
  	if (unlikely(!ret)) {
  		ftrace_graph_stop();
  		WARN_ON(1);
  		/* Might as well panic. What else to do? */
  		ret = (unsigned long)panic;
  	}
  
  	return ret;
  }

  /**
   * ftrace_graph_ret_addr - convert a potentially modified stack return address
   *			   to its original value
   *
   * This function can be called by stack unwinding code to convert a found stack
   * return address ('ret') to its original value, in case the function graph
   * tracer has modified it to be 'return_to_handler'.  If the address hasn't
   * been modified, the unchanged value of 'ret' is returned.
   *
   * 'idx' is a state variable which should be initialized by the caller to zero
   * before the first call.
   *
   * 'retp' is a pointer to the return address on the stack.  It's ignored if
   * the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
   */
  #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
  				    unsigned long ret, unsigned long *retp)
  {
  	int index = task->curr_ret_stack;
  	int i;
  
  	if (ret != (unsigned long)return_to_handler)
  		return ret;
  
  	if (index < -1)
  		index += FTRACE_NOTRACE_DEPTH;
  
  	if (index < 0)
  		return ret;
  
  	for (i = 0; i <= index; i++)
  		if (task->ret_stack[i].retp == retp)
  			return task->ret_stack[i].ret;
  
  	return ret;
  }
  #else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
  unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
  				    unsigned long ret, unsigned long *retp)
  {
  	int task_idx;
  
  	if (ret != (unsigned long)return_to_handler)
  		return ret;
  
  	task_idx = task->curr_ret_stack;
  
  	if (!task->ret_stack || task_idx < *idx)
  		return ret;
  
  	task_idx -= *idx;
  	(*idx)++;
  
  	return task->ret_stack[task_idx].ret;
  }
  #endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */

  int __trace_graph_entry(struct trace_array *tr,

  				struct ftrace_graph_ent *trace,
  				unsigned long flags,
  				int pc)
  {

  	struct trace_event_call *call = &event_funcgraph_entry;

  	struct ring_buffer_event *event;

  	struct ring_buffer *buffer = tr->trace_buffer.buffer;

  	struct ftrace_graph_ent_entry *entry;

  	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,

  					  sizeof(*entry), flags, pc);
  	if (!event)
  		return 0;
  	entry	= ring_buffer_event_data(event);
  	entry->graph_ent			= *trace;

  	if (!call_filter_check_discard(call, entry, buffer, event))

  		trace_buffer_unlock_commit_nostack(buffer, event);

  
  	return 1;
  }

  static inline int ftrace_graph_ignore_irqs(void)
  {

  	if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))

  		return 0;
  
  	return in_irq();
  }

  int trace_graph_entry(struct ftrace_graph_ent *trace)
  {
  	struct trace_array *tr = graph_array;
  	struct trace_array_cpu *data;
  	unsigned long flags;
  	long disabled;
  	int ret;
  	int cpu;
  	int pc;

  	if (!ftrace_trace_task(tr))

  		return 0;

  	if (ftrace_graph_ignore_func(trace))
  		return 0;
  
  	if (ftrace_graph_ignore_irqs())

  		return 0;

  	/*
  	 * Do not trace a function if it's filtered by set_graph_notrace.
  	 * Make the index of ret stack negative to indicate that it should
  	 * ignore further functions.  But it needs its own ret stack entry
  	 * to recover the original index in order to continue tracing after
  	 * returning from the function.
  	 */
  	if (ftrace_graph_notrace_addr(trace->func))
  		return 1;

  	/*
  	 * Stop here if tracing_threshold is set. We only write function return
  	 * events to the ring buffer.
  	 */
  	if (tracing_thresh)
  		return 1;

  	local_irq_save(flags);
  	cpu = raw_smp_processor_id();

  	data = per_cpu_ptr(tr->trace_buffer.data, cpu);

  	disabled = atomic_inc_return(&data->disabled);
  	if (likely(disabled == 1)) {
  		pc = preempt_count();
  		ret = __trace_graph_entry(tr, trace, flags, pc);
  	} else {
  		ret = 0;
  	}

  
  	atomic_dec(&data->disabled);
  	local_irq_restore(flags);
  
  	return ret;
  }

  static void
  __trace_graph_function(struct trace_array *tr,
  		unsigned long ip, unsigned long flags, int pc)
  {
  	u64 time = trace_clock_local();
  	struct ftrace_graph_ent ent = {
  		.func  = ip,
  		.depth = 0,
  	};
  	struct ftrace_graph_ret ret = {
  		.func     = ip,
  		.depth    = 0,
  		.calltime = time,
  		.rettime  = time,
  	};
  
  	__trace_graph_entry(tr, &ent, flags, pc);
  	__trace_graph_return(tr, &ret, flags, pc);
  }
  
  void
  trace_graph_function(struct trace_array *tr,
  		unsigned long ip, unsigned long parent_ip,
  		unsigned long flags, int pc)
  {

  	__trace_graph_function(tr, ip, flags, pc);
  }

  void __trace_graph_return(struct trace_array *tr,

  				struct ftrace_graph_ret *trace,
  				unsigned long flags,
  				int pc)
  {

  	struct trace_event_call *call = &event_funcgraph_exit;

  	struct ring_buffer_event *event;

  	struct ring_buffer *buffer = tr->trace_buffer.buffer;

  	struct ftrace_graph_ret_entry *entry;

  	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,

  					  sizeof(*entry), flags, pc);
  	if (!event)
  		return;
  	entry	= ring_buffer_event_data(event);
  	entry->ret				= *trace;

  	if (!call_filter_check_discard(call, entry, buffer, event))

  		trace_buffer_unlock_commit_nostack(buffer, event);

  }
  
  void trace_graph_return(struct ftrace_graph_ret *trace)
  {
  	struct trace_array *tr = graph_array;
  	struct trace_array_cpu *data;
  	unsigned long flags;
  	long disabled;
  	int cpu;
  	int pc;

  	ftrace_graph_addr_finish(trace);

  	local_irq_save(flags);
  	cpu = raw_smp_processor_id();

  	data = per_cpu_ptr(tr->trace_buffer.data, cpu);

  	disabled = atomic_inc_return(&data->disabled);
  	if (likely(disabled == 1)) {
  		pc = preempt_count();
  		__trace_graph_return(tr, trace, flags, pc);
  	}

  	atomic_dec(&data->disabled);
  	local_irq_restore(flags);
  }

  void set_graph_array(struct trace_array *tr)
  {
  	graph_array = tr;
  
  	/* Make graph_array visible before we start tracing */
  
  	smp_mb();
  }

  static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)

  {

  	ftrace_graph_addr_finish(trace);

  	if (tracing_thresh &&
  	    (trace->rettime - trace->calltime < tracing_thresh))
  		return;
  	else
  		trace_graph_return(trace);
  }

  static int graph_trace_init(struct trace_array *tr)
  {

  	int ret;

  	set_graph_array(tr);

  	if (tracing_thresh)
  		ret = register_ftrace_graph(&trace_graph_thresh_return,

  					    &trace_graph_entry);

  	else
  		ret = register_ftrace_graph(&trace_graph_return,
  					    &trace_graph_entry);

  	if (ret)
  		return ret;
  	tracing_start_cmdline_record();
  
  	return 0;

  }
  
  static void graph_trace_reset(struct trace_array *tr)
  {

  	tracing_stop_cmdline_record();
  	unregister_ftrace_graph();

  }

  static int graph_trace_update_thresh(struct trace_array *tr)

  {
  	graph_trace_reset(tr);
  	return graph_trace_init(tr);
  }

  static int max_bytes_for_cpu;

  static void print_graph_cpu(struct trace_seq *s, int cpu)

  {

  	/*
  	 * Start with a space character - to make it stand out
  	 * to the right a bit when trace output is pasted into
  	 * email:
  	 */

  	trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);

  }

  #define TRACE_GRAPH_PROCINFO_LENGTH	14

  static void print_graph_proc(struct trace_seq *s, pid_t pid)

  {

  	char comm[TASK_COMM_LEN];

  	/* sign + log10(MAX_INT) + '\0' */
  	char pid_str[11];

  	int spaces = 0;

  	int len;
  	int i;

  	trace_find_cmdline(pid, comm);

  	comm[7] = '\0';
  	sprintf(pid_str, "%d", pid);
  
  	/* 1 stands for the "-" character */
  	len = strlen(comm) + strlen(pid_str) + 1;
  
  	if (len < TRACE_GRAPH_PROCINFO_LENGTH)
  		spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
  
  	/* First spaces to align center */

  	for (i = 0; i < spaces / 2; i++)
  		trace_seq_putc(s, ' ');

  	trace_seq_printf(s, "%s-%s", comm, pid_str);

  
  	/* Last spaces to align center */

  	for (i = 0; i < spaces - (spaces / 2); i++)
  		trace_seq_putc(s, ' ');

  }

  static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)

  {

  	trace_seq_putc(s, ' ');
  	trace_print_lat_fmt(s, entry);

  }

  /* If the pid changed since the last trace, output this event */

  static void

  verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)

  {

  	pid_t prev_pid;

  	pid_t *last_pid;

  	if (!data)

  		return;

  	last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);

  
  	if (*last_pid == pid)

  		return;

  	prev_pid = *last_pid;
  	*last_pid = pid;

  	if (prev_pid == -1)

  		return;

  /*
   * Context-switch trace line:
  
   ------------------------------------------
   | 1)  migration/0--1  =>  sshd-1755
   ------------------------------------------
  
   */

  	trace_seq_puts(s, " ------------------------------------------
  ");
  	print_graph_cpu(s, cpu);
  	print_graph_proc(s, prev_pid);
  	trace_seq_puts(s, " => ");
  	print_graph_proc(s, pid);
  	trace_seq_puts(s, "
   ------------------------------------------
  
  ");

  }

  static struct ftrace_graph_ret_entry *
  get_return_for_leaf(struct trace_iterator *iter,

  		struct ftrace_graph_ent_entry *curr)
  {

  	struct fgraph_data *data = iter->private;
  	struct ring_buffer_iter *ring_iter = NULL;

  	struct ring_buffer_event *event;
  	struct ftrace_graph_ret_entry *next;

  	/*
  	 * If the previous output failed to write to the seq buffer,
  	 * then we just reuse the data from before.
  	 */
  	if (data && data->failed) {
  		curr = &data->ent;
  		next = &data->ret;
  	} else {

  		ring_iter = trace_buffer_iter(iter, iter->cpu);

  
  		/* First peek to compare current entry and the next one */
  		if (ring_iter)
  			event = ring_buffer_iter_peek(ring_iter, NULL);
  		else {
  			/*
  			 * We need to consume the current entry to see
  			 * the next one.
  			 */

  			ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,

  					    NULL, NULL);

  			event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,

  						 NULL, NULL);

  		}

  		if (!event)
  			return NULL;
  
  		next = ring_buffer_event_data(event);

  		if (data) {
  			/*
  			 * Save current and next entries for later reference
  			 * if the output fails.
  			 */
  			data->ent = *curr;

  			/*
  			 * If the next event is not a return type, then
  			 * we only care about what type it is. Otherwise we can
  			 * safely copy the entire event.
  			 */
  			if (next->ent.type == TRACE_GRAPH_RET)
  				data->ret = *next;
  			else
  				data->ret.ent.type = next->ent.type;

  		}
  	}

  
  	if (next->ent.type != TRACE_GRAPH_RET)

  		return NULL;

  
  	if (curr->ent.pid != next->ent.pid ||
  			curr->graph_ent.func != next->ret.func)

  		return NULL;

  	/* this is a leaf, now advance the iterator */
  	if (ring_iter)
  		ring_buffer_read(ring_iter, NULL);
  
  	return next;

  }

  static void print_graph_abs_time(u64 t, struct trace_seq *s)

  {
  	unsigned long usecs_rem;
  
  	usecs_rem = do_div(t, NSEC_PER_SEC);
  	usecs_rem /= 1000;

  	trace_seq_printf(s, "%5lu.%06lu |  ",
  			 (unsigned long)t, usecs_rem);

  }

  static void

  print_graph_irq(struct trace_iterator *iter, unsigned long addr,

  		enum trace_type type, int cpu, pid_t pid, u32 flags)

  {

  	struct trace_array *tr = iter->tr;

  	struct trace_seq *s = &iter->seq;

  	struct trace_entry *ent = iter->ent;

  
  	if (addr < (unsigned long)__irqentry_text_start ||
  		addr >= (unsigned long)__irqentry_text_end)

  		return;

  	if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {

  		/* Absolute time */

  		if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
  			print_graph_abs_time(iter->ts, s);

  		/* Cpu */

  		if (flags & TRACE_GRAPH_PRINT_CPU)
  			print_graph_cpu(s, cpu);

  		/* Proc */
  		if (flags & TRACE_GRAPH_PRINT_PROC) {

  			print_graph_proc(s, pid);
  			trace_seq_puts(s, " | ");

  		}

  
  		/* Latency format */

  		if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)

  			print_graph_lat_fmt(s, ent);

  	}

  	/* No overhead */

  	print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START);

  	if (type == TRACE_GRAPH_ENT)

  		trace_seq_puts(s, "==========>");

  	else

  		trace_seq_puts(s, "<==========");

  	print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END);

  	trace_seq_putc(s, '
  ');

  }

  void

  trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)

  {
  	unsigned long nsecs_rem = do_div(duration, 1000);

  	/* log10(ULONG_MAX) + '\0' */

  	char usecs_str[21];

  	char nsecs_str[5];

  	int len;

  	int i;

  	sprintf(usecs_str, "%lu", (unsigned long) duration);

  
  	/* Print msecs */

  	trace_seq_printf(s, "%s", usecs_str);

  	len = strlen(usecs_str);

  
  	/* Print nsecs (we don't want to exceed 7 numbers) */
  	if (len < 7) {

  		size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
  
  		snprintf(nsecs_str, slen, "%03lu", nsecs_rem);

  		trace_seq_printf(s, ".%s", nsecs_str);

  		len += strlen(nsecs_str) + 1;

  	}

  	trace_seq_puts(s, " us ");

  
  	/* Print remaining spaces to fit the row's width */

  	for (i = len; i < 8; i++)

  		trace_seq_putc(s, ' ');

  }

  static void

  print_graph_duration(struct trace_array *tr, unsigned long long duration,
  		     struct trace_seq *s, u32 flags)

  {

  	if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||

  	    !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))

  		return;

  
  	/* No real adata, just filling the column with spaces */

  	switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
  	case FLAGS_FILL_FULL:

  		trace_seq_puts(s, "              |  ");
  		return;

  	case FLAGS_FILL_START:

  		trace_seq_puts(s, "  ");
  		return;

  	case FLAGS_FILL_END:

  		trace_seq_puts(s, " |");
  		return;

  	}
  
  	/* Signal a overhead of time execution to the output */

  	if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
  		trace_seq_printf(s, "%c ", trace_find_mark(duration));
  	else

  		trace_seq_puts(s, "  ");

  	trace_print_graph_duration(duration, s);
  	trace_seq_puts(s, "|  ");

  }

  /* Case of a leaf function on its call entry */

  static enum print_line_t

  print_graph_entry_leaf(struct trace_iterator *iter,

  		struct ftrace_graph_ent_entry *entry,

  		struct ftrace_graph_ret_entry *ret_entry,
  		struct trace_seq *s, u32 flags)

  {

  	struct fgraph_data *data = iter->private;

  	struct trace_array *tr = iter->tr;

  	struct ftrace_graph_ret *graph_ret;

  	struct ftrace_graph_ent *call;
  	unsigned long long duration;

  	int cpu = iter->cpu;

  	int i;

  	graph_ret = &ret_entry->ret;
  	call = &entry->graph_ent;
  	duration = graph_ret->rettime - graph_ret->calltime;

  	if (data) {

  		struct fgraph_cpu_data *cpu_data;

  
  		cpu_data = per_cpu_ptr(data->cpu_data, cpu);

  		/* If a graph tracer ignored set_graph_notrace */
  		if (call->depth < -1)
  			call->depth += FTRACE_NOTRACE_DEPTH;

  		/*
  		 * Comments display at + 1 to depth. Since
  		 * this is a leaf function, keep the comments
  		 * equal to this depth.
  		 */

  		cpu_data->depth = call->depth - 1;
  
  		/* No need to keep this function around for this depth */

  		if (call->depth < FTRACE_RETFUNC_DEPTH &&
  		    !WARN_ON_ONCE(call->depth < 0))

  			cpu_data->enter_funcs[call->depth] = 0;

  	}

  	/* Overhead and duration */

  	print_graph_duration(tr, duration, s, flags);

  	/* Function */

  	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
  		trace_seq_putc(s, ' ');

  	trace_seq_printf(s, "%ps();
  ", (void *)call->func);

  	print_graph_irq(iter, graph_ret->func, TRACE_GRAPH_RET,
  			cpu, iter->ent->pid, flags);

  	return trace_handle_return(s);

  }
  
  static enum print_line_t

  print_graph_entry_nested(struct trace_iterator *iter,
  			 struct ftrace_graph_ent_entry *entry,

  			 struct trace_seq *s, int cpu, u32 flags)

  {

  	struct ftrace_graph_ent *call = &entry->graph_ent;

  	struct fgraph_data *data = iter->private;

  	struct trace_array *tr = iter->tr;

  	int i;
  
  	if (data) {

  		struct fgraph_cpu_data *cpu_data;

  		int cpu = iter->cpu;

  		/* If a graph tracer ignored set_graph_notrace */
  		if (call->depth < -1)
  			call->depth += FTRACE_NOTRACE_DEPTH;

  		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
  		cpu_data->depth = call->depth;
  
  		/* Save this function pointer to see if the exit matches */

  		if (call->depth < FTRACE_RETFUNC_DEPTH &&
  		    !WARN_ON_ONCE(call->depth < 0))

  			cpu_data->enter_funcs[call->depth] = call->func;

  	}

  	/* No time */

  	print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);

  	/* Function */

  	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
  		trace_seq_putc(s, ' ');
  
  	trace_seq_printf(s, "%ps() {
  ", (void *)call->func);

  	if (trace_seq_has_overflowed(s))

  		return TRACE_TYPE_PARTIAL_LINE;

  	/*
  	 * we already consumed the current entry to check the next one
  	 * and see if this is a leaf.
  	 */
  	return TRACE_TYPE_NO_CONSUME;

  }

  static void

  print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,

  		     int type, unsigned long addr, u32 flags)

  {

  	struct fgraph_data *data = iter->private;

  	struct trace_entry *ent = iter->ent;

  	struct trace_array *tr = iter->tr;

  	int cpu = iter->cpu;

  	/* Pid */

  	verif_pid(s, ent->pid, cpu, data);

  	if (type)

  		/* Interrupt */

  		print_graph_irq(iter, addr, type, cpu, ent->pid, flags);

  	if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))

  		return;

  	/* Absolute time */

  	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
  		print_graph_abs_time(iter->ts, s);

  	/* Cpu */

  	if (flags & TRACE_GRAPH_PRINT_CPU)
  		print_graph_cpu(s, cpu);

  
  	/* Proc */

  	if (flags & TRACE_GRAPH_PRINT_PROC) {

  		print_graph_proc(s, ent->pid);
  		trace_seq_puts(s, " | ");

  	}

  	/* Latency format */

  	if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)

  		print_graph_lat_fmt(s, ent);

  	return;

  }

  /*
   * Entry check for irq code
   *
   * returns 1 if
   *  - we are inside irq code

   *  - we just entered irq code

   *
   * retunns 0 if
   *  - funcgraph-interrupts option is set
   *  - we are not inside irq code
   */
  static int
  check_irq_entry(struct trace_iterator *iter, u32 flags,
  		unsigned long addr, int depth)
  {
  	int cpu = iter->cpu;

  	int *depth_irq;

  	struct fgraph_data *data = iter->private;

  	/*
  	 * If we are either displaying irqs, or we got called as
  	 * a graph event and private data does not exist,
  	 * then we bypass the irq check.
  	 */
  	if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
  	    (!data))

  		return 0;

  	depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

  	/*
  	 * We are inside the irq code
  	 */
  	if (*depth_irq >= 0)
  		return 1;
  
  	if ((addr < (unsigned long)__irqentry_text_start) ||
  	    (addr >= (unsigned long)__irqentry_text_end))
  		return 0;
  
  	/*
  	 * We are entering irq code.
  	 */
  	*depth_irq = depth;
  	return 1;
  }
  
  /*
   * Return check for irq code
   *
   * returns 1 if
   *  - we are inside irq code
   *  - we just left irq code
   *
   * returns 0 if
   *  - funcgraph-interrupts option is set
   *  - we are not inside irq code
   */
  static int
  check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
  {
  	int cpu = iter->cpu;

  	int *depth_irq;

  	struct fgraph_data *data = iter->private;

  	/*
  	 * If we are either displaying irqs, or we got called as
  	 * a graph event and private data does not exist,
  	 * then we bypass the irq check.
  	 */
  	if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
  	    (!data))

  		return 0;

  	depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

  	/*
  	 * We are not inside the irq code.
  	 */
  	if (*depth_irq == -1)
  		return 0;
  
  	/*
  	 * We are inside the irq code, and this is returning entry.
  	 * Let's not trace it and clear the entry depth, since
  	 * we are out of irq code.
  	 *
  	 * This condition ensures that we 'leave the irq code' once
  	 * we are out of the entry depth. Thus protecting us from
  	 * the RETURN entry loss.
  	 */
  	if (*depth_irq >= depth) {
  		*depth_irq = -1;
  		return 1;
  	}
  
  	/*
  	 * We are inside the irq code, and this is not the entry.
  	 */
  	return 1;
  }

  static enum print_line_t
  print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,

  			struct trace_iterator *iter, u32 flags)

  {

  	struct fgraph_data *data = iter->private;

  	struct ftrace_graph_ent *call = &field->graph_ent;
  	struct ftrace_graph_ret_entry *leaf_ret;

  	static enum print_line_t ret;
  	int cpu = iter->cpu;

  	if (check_irq_entry(iter, flags, call->func, call->depth))
  		return TRACE_TYPE_HANDLED;

  	print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);

  	leaf_ret = get_return_for_leaf(iter, field);
  	if (leaf_ret)

  		ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);

  	else

  		ret = print_graph_entry_nested(iter, field, s, cpu, flags);

  	if (data) {
  		/*
  		 * If we failed to write our output, then we need to make
  		 * note of it. Because we already consumed our entry.
  		 */
  		if (s->full) {
  			data->failed = 1;
  			data->cpu = cpu;
  		} else
  			data->failed = 0;
  	}
  
  	return ret;

  }
  
  static enum print_line_t

  print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,

  		   struct trace_entry *ent, struct trace_iterator *iter,
  		   u32 flags)

  {

  	unsigned long long duration = trace->rettime - trace->calltime;

  	struct fgraph_data *data = iter->private;

  	struct trace_array *tr = iter->tr;

  	pid_t pid = ent->pid;
  	int cpu = iter->cpu;

  	int func_match = 1;

  	int i;

  	if (check_irq_return(iter, flags, trace->depth))
  		return TRACE_TYPE_HANDLED;

  	if (data) {

  		struct fgraph_cpu_data *cpu_data;
  		int cpu = iter->cpu;
  
  		cpu_data = per_cpu_ptr(data->cpu_data, cpu);

  
  		/*
  		 * Comments display at + 1 to depth. This is the
  		 * return from a function, we now want the comments
  		 * to display at the same level of the bracket.
  		 */

  		cpu_data->depth = trace->depth - 1;

  		if (trace->depth < FTRACE_RETFUNC_DEPTH &&
  		    !WARN_ON_ONCE(trace->depth < 0)) {

  			if (cpu_data->enter_funcs[trace->depth] != trace->func)
  				func_match = 0;
  			cpu_data->enter_funcs[trace->depth] = 0;
  		}

  	}

  	print_graph_prologue(iter, s, 0, 0, flags);

  	/* Overhead and duration */

  	print_graph_duration(tr, duration, s, flags);

  	/* Closing brace */

  	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
  		trace_seq_putc(s, ' ');

  	/*
  	 * If the return function does not have a matching entry,
  	 * then the entry was lost. Instead of just printing
  	 * the '}' and letting the user guess what function this

  	 * belongs to, write out the function name. Always do
  	 * that if the funcgraph-tail option is enabled.

  	 */

  	if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
  		trace_seq_puts(s, "}
  ");
  	else
  		trace_seq_printf(s, "} /* %ps */
  ", (void *)trace->func);

  	/* Overrun */

  	if (flags & TRACE_GRAPH_PRINT_OVERRUN)
  		trace_seq_printf(s, " (Overruns: %lu)
  ",
  				 trace->overrun);

  	print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
  			cpu, pid, flags);

  	return trace_handle_return(s);

  }

  static enum print_line_t

  print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
  		    struct trace_iterator *iter, u32 flags)

  {

  	struct trace_array *tr = iter->tr;
  	unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);

  	struct fgraph_data *data = iter->private;

  	struct trace_event *event;

  	int depth = 0;

  	int ret;

  	int i;
  
  	if (data)

  		depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;

  	print_graph_prologue(iter, s, 0, 0, flags);

  	/* No time */

  	print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);

  	/* Indentation */

  	if (depth > 0)

  		for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
  			trace_seq_putc(s, ' ');

  
  	/* The comment */

  	trace_seq_puts(s, "/* ");

  	switch (iter->ent->type) {

  	case TRACE_BPUTS:
  		ret = trace_print_bputs_msg_only(iter);
  		if (ret != TRACE_TYPE_HANDLED)
  			return ret;
  		break;

  	case TRACE_BPRINT:
  		ret = trace_print_bprintk_msg_only(iter);
  		if (ret != TRACE_TYPE_HANDLED)
  			return ret;
  		break;
  	case TRACE_PRINT:
  		ret = trace_print_printk_msg_only(iter);
  		if (ret != TRACE_TYPE_HANDLED)
  			return ret;
  		break;
  	default:
  		event = ftrace_find_event(ent->type);
  		if (!event)
  			return TRACE_TYPE_UNHANDLED;

  		ret = event->funcs->trace(iter, sym_flags, event);

  		if (ret != TRACE_TYPE_HANDLED)
  			return ret;
  	}

  	if (trace_seq_has_overflowed(s))
  		goto out;

  	/* Strip ending newline */

  	if (s->buffer[s->seq.len - 1] == '
  ') {
  		s->buffer[s->seq.len - 1] = '\0';
  		s->seq.len--;

  	}

  	trace_seq_puts(s, " */
  ");

   out:

  	return trace_handle_return(s);

  }

  enum print_line_t

  print_graph_function_flags(struct trace_iterator *iter, u32 flags)

  {

  	struct ftrace_graph_ent_entry *field;
  	struct fgraph_data *data = iter->private;

  	struct trace_entry *entry = iter->ent;

  	struct trace_seq *s = &iter->seq;

  	int cpu = iter->cpu;
  	int ret;
  
  	if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
  		per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
  		return TRACE_TYPE_HANDLED;
  	}
  
  	/*
  	 * If the last output failed, there's a possibility we need
  	 * to print out the missing entry which would never go out.
  	 */
  	if (data && data->failed) {
  		field = &data->ent;
  		iter->cpu = data->cpu;

  		ret = print_graph_entry(field, s, iter, flags);

  		if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
  			per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
  			ret = TRACE_TYPE_NO_CONSUME;
  		}
  		iter->cpu = cpu;
  		return ret;
  	}

  	switch (entry->type) {
  	case TRACE_GRAPH_ENT: {

  		/*
  		 * print_graph_entry() may consume the current event,
  		 * thus @field may become invalid, so we need to save it.
  		 * sizeof(struct ftrace_graph_ent_entry) is very small,
  		 * it can be safely saved at the stack.
  		 */

  		struct ftrace_graph_ent_entry saved;

  		trace_assign_type(field, entry);

  		saved = *field;

  		return print_graph_entry(&saved, s, iter, flags);

  	}
  	case TRACE_GRAPH_RET: {
  		struct ftrace_graph_ret_entry *field;
  		trace_assign_type(field, entry);

  		return print_graph_return(&field->ret, s, entry, iter, flags);

  	}

  	case TRACE_STACK:
  	case TRACE_FN:
  		/* dont trace stack and functions as comments */
  		return TRACE_TYPE_UNHANDLED;

  	default:

  		return print_graph_comment(s, entry, iter, flags);

  	}

  
  	return TRACE_TYPE_HANDLED;

  }

  static enum print_line_t

  print_graph_function(struct trace_iterator *iter)
  {

  	return print_graph_function_flags(iter, tracer_flags.val);

  }
  
  static enum print_line_t

  print_graph_function_event(struct trace_iterator *iter, int flags,
  			   struct trace_event *event)

  {
  	return print_graph_function(iter);
  }

  static void print_lat_header(struct seq_file *s, u32 flags)

  {
  	static const char spaces[] = "                "	/* 16 spaces */
  		"    "					/* 4 spaces */
  		"                 ";			/* 17 spaces */
  	int size = 0;

  	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)

  		size += 16;

  	if (flags & TRACE_GRAPH_PRINT_CPU)

  		size += 4;

  	if (flags & TRACE_GRAPH_PRINT_PROC)

  		size += 17;
  
  	seq_printf(s, "#%.*s  _-----=> irqs-off        
  ", size, spaces);
  	seq_printf(s, "#%.*s / _----=> need-resched    
  ", size, spaces);
  	seq_printf(s, "#%.*s| / _---=> hardirq/softirq 
  ", size, spaces);
  	seq_printf(s, "#%.*s|| / _--=> preempt-depth   
  ", size, spaces);

  	seq_printf(s, "#%.*s||| /                      
  ", size, spaces);

  }

  static void __print_graph_headers_flags(struct trace_array *tr,
  					struct seq_file *s, u32 flags)

  {

  	int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT;

  
  	if (lat)

  		print_lat_header(s, flags);

  	/* 1st line */

  	seq_putc(s, '#');

  	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)

  		seq_puts(s, "     TIME       ");

  	if (flags & TRACE_GRAPH_PRINT_CPU)

  		seq_puts(s, " CPU");

  	if (flags & TRACE_GRAPH_PRINT_PROC)

  		seq_puts(s, "  TASK/PID       ");

  	if (lat)

  		seq_puts(s, "||||");

  	if (flags & TRACE_GRAPH_PRINT_DURATION)

  		seq_puts(s, "  DURATION   ");
  	seq_puts(s, "               FUNCTION CALLS
  ");

  
  	/* 2nd line */

  	seq_putc(s, '#');

  	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)

  		seq_puts(s, "      |         ");

  	if (flags & TRACE_GRAPH_PRINT_CPU)

  		seq_puts(s, " |  ");

  	if (flags & TRACE_GRAPH_PRINT_PROC)

  		seq_puts(s, "   |    |        ");

  	if (lat)

  		seq_puts(s, "||||");

  	if (flags & TRACE_GRAPH_PRINT_DURATION)

  		seq_puts(s, "   |   |      ");
  	seq_puts(s, "               |   |   |   |
  ");

  }

  static void print_graph_headers(struct seq_file *s)

  {
  	print_graph_headers_flags(s, tracer_flags.val);
  }

  void print_graph_headers_flags(struct seq_file *s, u32 flags)
  {
  	struct trace_iterator *iter = s->private;

  	struct trace_array *tr = iter->tr;

  	if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))

  		return;

  	if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) {

  		/* print nothing if the buffers are empty */
  		if (trace_empty(iter))
  			return;
  
  		print_trace_header(s, iter);

  	}

  	__print_graph_headers_flags(tr, s, flags);

  }

  void graph_trace_open(struct trace_iterator *iter)

  {

  	/* pid and depth on the last trace processed */

  	struct fgraph_data *data;

  	gfp_t gfpflags;

  	int cpu;

  	iter->private = NULL;

  	/* We can be called in atomic context via ftrace_dump() */
  	gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
  
  	data = kzalloc(sizeof(*data), gfpflags);

  	if (!data)

  		goto out_err;

  	data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags);

  	if (!data->cpu_data)
  		goto out_err_free;
  
  	for_each_possible_cpu(cpu) {
  		pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
  		int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
  		int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);

  		int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

  		*pid = -1;
  		*depth = 0;
  		*ignore = 0;

  		*depth_irq = -1;

  	}

  	iter->private = data;

  
  	return;
  
   out_err_free:
  	kfree(data);
   out_err:

  	pr_warn("function graph tracer: not enough memory
  ");

  }

  void graph_trace_close(struct trace_iterator *iter)

  {

  	struct fgraph_data *data = iter->private;
  
  	if (data) {
  		free_percpu(data->cpu_data);
  		kfree(data);
  	}

  }

  static int
  func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)

  {
  	if (bit == TRACE_GRAPH_PRINT_IRQS)
  		ftrace_graph_skip_irqs = !set;

  	if (bit == TRACE_GRAPH_SLEEP_TIME)
  		ftrace_graph_sleep_time_control(set);
  
  	if (bit == TRACE_GRAPH_GRAPH_TIME)
  		ftrace_graph_graph_time_control(set);

  	return 0;
  }

  static struct trace_event_functions graph_functions = {
  	.trace		= print_graph_function_event,
  };

  static struct trace_event graph_trace_entry_event = {
  	.type		= TRACE_GRAPH_ENT,

  	.funcs		= &graph_functions,

  };
  
  static struct trace_event graph_trace_ret_event = {
  	.type		= TRACE_GRAPH_RET,

  	.funcs		= &graph_functions

  };

  static struct tracer graph_trace __tracer_data = {

  	.name		= "function_graph",

  	.update_thresh	= graph_trace_update_thresh,

  	.open		= graph_trace_open,

  	.pipe_open	= graph_trace_open,

  	.close		= graph_trace_close,

  	.pipe_close	= graph_trace_close,

  	.init		= graph_trace_init,
  	.reset		= graph_trace_reset,

  	.print_line	= print_graph_function,
  	.print_header	= print_graph_headers,

  	.flags		= &tracer_flags,

  	.set_flag	= func_graph_set_flag,

  #ifdef CONFIG_FTRACE_SELFTEST
  	.selftest	= trace_selftest_startup_function_graph,
  #endif

  };

  
  static ssize_t
  graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
  		  loff_t *ppos)
  {
  	unsigned long val;
  	int ret;
  
  	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
  	if (ret)
  		return ret;

  	fgraph_max_depth = val;

  
  	*ppos += cnt;
  
  	return cnt;
  }
  
  static ssize_t
  graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
  		 loff_t *ppos)
  {
  	char buf[15]; /* More than enough to hold UINT_MAX + "
  "*/
  	int n;