trace_functions_graph.c 33.1 KB
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/*
 *
 * Function graph tracer.
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 * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
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 * Mostly borrowed from function tracer which
 * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
 *
 */
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
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#include <linux/slab.h>
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#include <linux/fs.h>

#include "trace.h"
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#include "trace_output.h"
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/* When set, irq functions will be ignored */
static int ftrace_graph_skip_irqs;

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struct fgraph_cpu_data {
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	pid_t		last_pid;
	int		depth;
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	int		depth_irq;
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	int		ignore;
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	unsigned long	enter_funcs[FTRACE_RETFUNC_DEPTH];
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};

struct fgraph_data {
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	struct fgraph_cpu_data __percpu *cpu_data;
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	/* Place to preserve last processed entry. */
	struct ftrace_graph_ent_entry	ent;
	struct ftrace_graph_ret_entry	ret;
	int				failed;
	int				cpu;
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};

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#define TRACE_GRAPH_INDENT	2
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/* Flag options */
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#define TRACE_GRAPH_PRINT_OVERRUN	0x1
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#define TRACE_GRAPH_PRINT_CPU		0x2
#define TRACE_GRAPH_PRINT_OVERHEAD	0x4
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#define TRACE_GRAPH_PRINT_PROC		0x8
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#define TRACE_GRAPH_PRINT_DURATION	0x10
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#define TRACE_GRAPH_PRINT_ABS_TIME	0x20
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#define TRACE_GRAPH_PRINT_IRQS		0x40
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static struct tracer_opt trace_opts[] = {
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	/* Display overruns? (for self-debug purpose) */
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	{ 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) },
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	/* Display proc name/pid */
	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
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	/* 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) },
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	/* Display interrupts */
	{ TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
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	{ } /* Empty entry */
};

static struct tracer_flags tracer_flags = {
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	/* Don't display overruns and proc by default */
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	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
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	       TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS,
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	.opts = trace_opts
};

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static struct trace_array *graph_array;
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/* Add a function return address to the trace stack on thread info.*/
int
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ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
			 unsigned long frame_pointer)
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{
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	unsigned long long calltime;
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	int index;

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

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

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

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	calltime = trace_clock_local();

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	index = ++current->curr_ret_stack;
	barrier();
	current->ret_stack[index].ret = ret;
	current->ret_stack[index].func = func;
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	current->ret_stack[index].calltime = calltime;
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	current->ret_stack[index].subtime = 0;
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	current->ret_stack[index].fp = frame_pointer;
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	*depth = index;

	return 0;
}

/* Retrieve a function return address to the trace stack on thread info.*/
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static void
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ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
			unsigned long frame_pointer)
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{
	int index;

	index = current->curr_ret_stack;

	if (unlikely(index < 0)) {
		ftrace_graph_stop();
		WARN_ON(1);
		/* Might as well panic, otherwise we have no where to go */
		*ret = (unsigned long)panic;
		return;
	}

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#ifdef CONFIG_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.
	 */
	if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
		ftrace_graph_stop();
		WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
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		     "  from func %ps return to %lx\n",
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		     current->ret_stack[index].fp,
		     frame_pointer,
		     (void *)current->ret_stack[index].func,
		     current->ret_stack[index].ret);
		*ret = (unsigned long)panic;
		return;
	}
#endif

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	*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 = index;
}

/*
 * Send the trace to the ring-buffer.
 * @return the original return address.
 */
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unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
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{
	struct ftrace_graph_ret trace;
	unsigned long ret;

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	ftrace_pop_return_trace(&trace, &ret, frame_pointer);
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	trace.rettime = trace_clock_local();
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	ftrace_graph_return(&trace);
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	barrier();
	current->curr_ret_stack--;
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	if (unlikely(!ret)) {
		ftrace_graph_stop();
		WARN_ON(1);
		/* Might as well panic. What else to do? */
		ret = (unsigned long)panic;
	}

	return ret;
}

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int __trace_graph_entry(struct trace_array *tr,
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				struct ftrace_graph_ent *trace,
				unsigned long flags,
				int pc)
{
	struct ftrace_event_call *call = &event_funcgraph_entry;
	struct ring_buffer_event *event;
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	struct ring_buffer *buffer = tr->buffer;
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	struct ftrace_graph_ent_entry *entry;

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	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
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		return 0;

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	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
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					  sizeof(*entry), flags, pc);
	if (!event)
		return 0;
	entry	= ring_buffer_event_data(event);
	entry->graph_ent			= *trace;
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	if (!filter_current_check_discard(buffer, call, entry, event))
		ring_buffer_unlock_commit(buffer, event);
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	return 1;
}

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static inline int ftrace_graph_ignore_irqs(void)
{
	if (!ftrace_graph_skip_irqs)
		return 0;

	return in_irq();
}

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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(current))
		return 0;

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	/* trace it when it is-nested-in or is a function enabled. */
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	if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
	      ftrace_graph_ignore_irqs())
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		return 0;

	local_irq_save(flags);
	cpu = raw_smp_processor_id();
	data = tr->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;
}

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int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
{
	if (tracing_thresh)
		return 1;
	else
		return trace_graph_entry(trace);
}

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void __trace_graph_return(struct trace_array *tr,
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				struct ftrace_graph_ret *trace,
				unsigned long flags,
				int pc)
{
	struct ftrace_event_call *call = &event_funcgraph_exit;
	struct ring_buffer_event *event;
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	struct ring_buffer *buffer = tr->buffer;
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	struct ftrace_graph_ret_entry *entry;

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	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
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		return;

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	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
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					  sizeof(*entry), flags, pc);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	entry->ret				= *trace;
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	if (!filter_current_check_discard(buffer, call, entry, event))
		ring_buffer_unlock_commit(buffer, event);
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}

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;

	local_irq_save(flags);
	cpu = raw_smp_processor_id();
	data = tr->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);
}

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void set_graph_array(struct trace_array *tr)
{
	graph_array = tr;

	/* Make graph_array visible before we start tracing */

	smp_mb();
}

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void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
{
	if (tracing_thresh &&
	    (trace->rettime - trace->calltime < tracing_thresh))
		return;
	else
		trace_graph_return(trace);
}

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static int graph_trace_init(struct trace_array *tr)
{
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	int ret;

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	set_graph_array(tr);
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	if (tracing_thresh)
		ret = register_ftrace_graph(&trace_graph_thresh_return,
					    &trace_graph_thresh_entry);
	else
		ret = register_ftrace_graph(&trace_graph_return,
					    &trace_graph_entry);
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	if (ret)
		return ret;
	tracing_start_cmdline_record();

	return 0;
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}

static void graph_trace_reset(struct trace_array *tr)
{
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	tracing_stop_cmdline_record();
	unregister_ftrace_graph();
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}

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static int max_bytes_for_cpu;
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static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
	int ret;

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	/*
	 * Start with a space character - to make it stand out
	 * to the right a bit when trace output is pasted into
	 * email:
	 */
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	ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
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	if (!ret)
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		return TRACE_TYPE_PARTIAL_LINE;

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	return TRACE_TYPE_HANDLED;
}

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#define TRACE_GRAPH_PROCINFO_LENGTH	14

static enum print_line_t
print_graph_proc(struct trace_seq *s, pid_t pid)
{
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	char comm[TASK_COMM_LEN];
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	/* sign + log10(MAX_INT) + '\0' */
	char pid_str[11];
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	int spaces = 0;
	int ret;
	int len;
	int i;
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	trace_find_cmdline(pid, comm);
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	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++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Last spaces to align center */
	for (i = 0; i < spaces - (spaces / 2); i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
	return TRACE_TYPE_HANDLED;
}

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static enum print_line_t
print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
{
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	if (!trace_seq_putc(s, ' '))
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		return 0;

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	return trace_print_lat_fmt(s, entry);
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}

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/* If the pid changed since the last trace, output this event */
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static enum print_line_t
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verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
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{
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	pid_t prev_pid;
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	pid_t *last_pid;
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	int ret;
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	if (!data)
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		return TRACE_TYPE_HANDLED;

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	last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
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	if (*last_pid == pid)
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		return TRACE_TYPE_HANDLED;
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	prev_pid = *last_pid;
	*last_pid = pid;
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	if (prev_pid == -1)
		return TRACE_TYPE_HANDLED;
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/*
 * Context-switch trace line:

 ------------------------------------------
 | 1)  migration/0--1  =>  sshd-1755
 ------------------------------------------

 */
	ret = trace_seq_printf(s,
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		" ------------------------------------------\n");
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	if (!ret)
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		return TRACE_TYPE_PARTIAL_LINE;
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	ret = print_graph_cpu(s, cpu);
	if (ret == TRACE_TYPE_PARTIAL_LINE)
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		return TRACE_TYPE_PARTIAL_LINE;
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	ret = print_graph_proc(s, prev_pid);
	if (ret == TRACE_TYPE_PARTIAL_LINE)
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		return TRACE_TYPE_PARTIAL_LINE;
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	ret = trace_seq_printf(s, " => ");
	if (!ret)
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		return TRACE_TYPE_PARTIAL_LINE;
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	ret = print_graph_proc(s, pid);
	if (ret == TRACE_TYPE_PARTIAL_LINE)
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		return TRACE_TYPE_PARTIAL_LINE;
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	ret = trace_seq_printf(s,
		"\n ------------------------------------------\n\n");
	if (!ret)
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		return TRACE_TYPE_PARTIAL_LINE;
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	return TRACE_TYPE_HANDLED;
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}

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static struct ftrace_graph_ret_entry *
get_return_for_leaf(struct trace_iterator *iter,
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		struct ftrace_graph_ent_entry *curr)
{
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	struct fgraph_data *data = iter->private;
	struct ring_buffer_iter *ring_iter = NULL;
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	struct ring_buffer_event *event;
	struct ftrace_graph_ret_entry *next;

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	/*
	 * 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 {
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		ring_iter = iter->buffer_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.
			 */
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			ring_buffer_consume(iter->tr->buffer, iter->cpu,
					    NULL, NULL);
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			event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
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						 NULL, NULL);
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		}
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		if (!event)
			return NULL;

		next = ring_buffer_event_data(event);
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		if (data) {
			/*
			 * Save current and next entries for later reference
			 * if the output fails.
			 */
			data->ent = *curr;
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			/*
			 * 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;
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		}
	}
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	if (next->ent.type != TRACE_GRAPH_RET)
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		return NULL;
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	if (curr->ent.pid != next->ent.pid ||
			curr->graph_ent.func != next->ret.func)
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		return NULL;
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	/* this is a leaf, now advance the iterator */
	if (ring_iter)
		ring_buffer_read(ring_iter, NULL);

	return next;
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}

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/* Signal a overhead of time execution to the output */
static int
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print_graph_overhead(unsigned long long duration, struct trace_seq *s,
		     u32 flags)
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{
	/* If duration disappear, we don't need anything */
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	if (!(flags & TRACE_GRAPH_PRINT_DURATION))
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		return 1;

	/* Non nested entry or return */
	if (duration == -1)
		return trace_seq_printf(s, "  ");

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	if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
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		/* Duration exceeded 100 msecs */
		if (duration > 100000ULL)
			return trace_seq_printf(s, "! ");

		/* Duration exceeded 10 msecs */
		if (duration > 10000ULL)
			return trace_seq_printf(s, "+ ");
	}

	return trace_seq_printf(s, "  ");
}

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static int 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;

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

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static enum print_line_t
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print_graph_irq(struct trace_iterator *iter, unsigned long addr,
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		enum trace_type type, int cpu, pid_t pid, u32 flags)
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{
	int ret;
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	struct trace_seq *s = &iter->seq;
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	if (addr < (unsigned long)__irqentry_text_start ||
		addr >= (unsigned long)__irqentry_text_end)
		return TRACE_TYPE_UNHANDLED;

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	/* Absolute time */
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	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
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		ret = print_graph_abs_time(iter->ts, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

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	/* Cpu */
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	if (flags & TRACE_GRAPH_PRINT_CPU) {
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		ret = print_graph_cpu(s, cpu);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
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	/* Proc */
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	if (flags & TRACE_GRAPH_PRINT_PROC) {
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		ret = print_graph_proc(s, pid);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
		ret = trace_seq_printf(s, " | ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
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	/* No overhead */
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	ret = print_graph_overhead(-1, s, flags);
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	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
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	if (type == TRACE_GRAPH_ENT)
		ret = trace_seq_printf(s, "==========>");
	else
		ret = trace_seq_printf(s, "<==========");

	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Don't close the duration column if haven't one */
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	if (flags & TRACE_GRAPH_PRINT_DURATION)
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		trace_seq_printf(s, " |");
	ret = trace_seq_printf(s, "\n");
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	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
	return TRACE_TYPE_HANDLED;
}
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enum print_line_t
trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
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{
	unsigned long nsecs_rem = do_div(duration, 1000);
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	/* log10(ULONG_MAX) + '\0' */
	char msecs_str[21];
	char nsecs_str[5];
	int ret, len;
	int i;

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

	/* Print msecs */
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	ret = trace_seq_printf(s, "%s", msecs_str);
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	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	len = strlen(msecs_str);

	/* Print nsecs (we don't want to exceed 7 numbers) */
	if (len < 7) {
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		snprintf(nsecs_str, min(sizeof(nsecs_str), 8UL - len), "%03lu",
			 nsecs_rem);
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		ret = trace_seq_printf(s, ".%s", nsecs_str);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
		len += strlen(nsecs_str);
	}

	ret = trace_seq_printf(s, " us ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Print remaining spaces to fit the row's width */
	for (i = len; i < 7; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
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	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
print_graph_duration(unsigned long long duration, struct trace_seq *s)
{
	int ret;

	ret = trace_print_graph_duration(duration, s);
	if (ret != TRACE_TYPE_HANDLED)
		return ret;
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	ret = trace_seq_printf(s, "|  ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

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	return TRACE_TYPE_HANDLED;
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}

/* Case of a leaf function on its call entry */
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static enum print_line_t
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print_graph_entry_leaf(struct trace_iterator *iter,
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		struct ftrace_graph_ent_entry *entry,
709 710
		struct ftrace_graph_ret_entry *ret_entry,
		struct trace_seq *s, u32 flags)
711
{
712
	struct fgraph_data *data = iter->private;
713 714 715
	struct ftrace_graph_ret *graph_ret;
	struct ftrace_graph_ent *call;
	unsigned long long duration;
716
	int ret;
717
	int i;
718

719 720 721 722
	graph_ret = &ret_entry->ret;
	call = &entry->graph_ent;
	duration = graph_ret->rettime - graph_ret->calltime;

723
	if (data) {
724
		struct fgraph_cpu_data *cpu_data;
725
		int cpu = iter->cpu;
726 727

		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
728 729 730 731 732 733

		/*
		 * Comments display at + 1 to depth. Since
		 * this is a leaf function, keep the comments
		 * equal to this depth.
		 */
734 735 736 737 738
		cpu_data->depth = call->depth - 1;

		/* No need to keep this function around for this depth */
		if (call->depth < FTRACE_RETFUNC_DEPTH)
			cpu_data->enter_funcs[call->depth] = 0;
739 740
	}

741
	/* Overhead */
742
	ret = print_graph_overhead(duration, s, flags);
743 744
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
745 746

	/* Duration */
747
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
748 749 750 751
		ret = print_graph_duration(duration, s);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
752

753 754 755 756 757 758 759
	/* Function */
	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

760
	ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
761 762 763 764 765 766 767
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
768 769
print_graph_entry_nested(struct trace_iterator *iter,
			 struct ftrace_graph_ent_entry *entry,
770
			 struct trace_seq *s, int cpu, u32 flags)
771 772
{
	struct ftrace_graph_ent *call = &entry->graph_ent;
773 774 775 776 777
	struct fgraph_data *data = iter->private;
	int ret;
	int i;

	if (data) {
778
		struct fgraph_cpu_data *cpu_data;
779 780
		int cpu = iter->cpu;

781 782 783 784 785 786
		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)
			cpu_data->enter_funcs[call->depth] = call->func;
787
	}
788 789

	/* No overhead */
790
	ret = print_graph_overhead(-1, s, flags);
791 792
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
793

794
	/* No time */
795
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
796 797 798 799 800
		ret = trace_seq_printf(s, "            |  ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

801
	/* Function */
802 803
	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
804 805
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
806 807
	}

808
	ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
809 810 811
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

812 813 814 815 816
	/*
	 * we already consumed the current entry to check the next one
	 * and see if this is a leaf.
	 */
	return TRACE_TYPE_NO_CONSUME;
817 818
}

819
static enum print_line_t
820
print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
821
		     int type, unsigned long addr, u32 flags)
822
{
823
	struct fgraph_data *data = iter->private;
824
	struct trace_entry *ent = iter->ent;
825 826
	int cpu = iter->cpu;
	int ret;
827

828
	/* Pid */
829
	if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
830 831
		return TRACE_TYPE_PARTIAL_LINE;

832 833
	if (type) {
		/* Interrupt */
834
		ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
835 836 837
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
838

839
	/* Absolute time */
840
	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
841 842 843 844 845
		ret = print_graph_abs_time(iter->ts, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

846
	/* Cpu */
847
	if (flags & TRACE_GRAPH_PRINT_CPU) {
848
		ret = print_graph_cpu(s, cpu);
849 850 851 852 853
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Proc */
854
	if (flags & TRACE_GRAPH_PRINT_PROC) {
855
		ret = print_graph_proc(s, ent->pid);
856 857 858 859
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;

		ret = trace_seq_printf(s, " | ");
860 861 862
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
863

864 865 866 867 868 869 870
	/* Latency format */
	if (trace_flags & TRACE_ITER_LATENCY_FMT) {
		ret = print_graph_lat_fmt(s, ent);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}

871 872 873
	return 0;
}

874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959
/*
 * Entry check for irq code
 *
 * returns 1 if
 *  - we are inside irq code
 *  - we just extered 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;
	struct fgraph_data *data = iter->private;
	int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

	if (flags & TRACE_GRAPH_PRINT_IRQS)
		return 0;

	/*
	 * 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;
	struct fgraph_data *data = iter->private;
	int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

	if (flags & TRACE_GRAPH_PRINT_IRQS)
		return 0;

	/*
	 * 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;
}

960 961
static enum print_line_t
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
962
			struct trace_iterator *iter, u32 flags)
963
{
964
	struct fgraph_data *data = iter->private;
965 966
	struct ftrace_graph_ent *call = &field->graph_ent;
	struct ftrace_graph_ret_entry *leaf_ret;
967 968
	static enum print_line_t ret;
	int cpu = iter->cpu;
969

970 971 972
	if (check_irq_entry(iter, flags, call->func, call->depth))
		return TRACE_TYPE_HANDLED;

973
	if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
974 975
		return TRACE_TYPE_PARTIAL_LINE;

976 977
	leaf_ret = get_return_for_leaf(iter, field);
	if (leaf_ret)
978
		ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
979
	else
980
		ret = print_graph_entry_nested(iter, field, s, cpu, flags);
981

982 983 984 985 986 987 988 989 990 991 992 993 994
	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;
995 996
}

997 998
static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
999 1000
		   struct trace_entry *ent, struct trace_iterator *iter,
		   u32 flags)
1001
{
1002
	unsigned long long duration = trace->rettime - trace->calltime;
1003 1004 1005
	struct fgraph_data *data = iter->private;
	pid_t pid = ent->pid;
	int cpu = iter->cpu;
1006
	int func_match = 1;
1007 1008 1009
	int ret;
	int i;

1010 1011 1012
	if (check_irq_return(iter, flags, trace->depth))
		return TRACE_TYPE_HANDLED;

1013
	if (data) {
1014 1015 1016 1017
		struct fgraph_cpu_data *cpu_data;
		int cpu = iter->cpu;

		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1018 1019 1020 1021 1022 1023

		/*
		 * 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.
		 */
1024 1025 1026 1027 1028 1029 1030
		cpu_data->depth = trace->depth - 1;

		if (trace->depth < FTRACE_RETFUNC_DEPTH) {
			if (cpu_data->enter_funcs[trace->depth] != trace->func)
				func_match = 0;
			cpu_data->enter_funcs[trace->depth] = 0;
		}
1031
	}
1032

1033
	if (print_graph_prologue(iter, s, 0, 0, flags))
1034 1035
		return TRACE_TYPE_PARTIAL_LINE;

1036
	/* Overhead */
1037
	ret = print_graph_overhead(duration, s, flags);
1038 1039
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
1040 1041

	/* Duration */
1042
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
1043 1044 1045 1046
		ret = print_graph_duration(duration, s);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
1047 1048

	/* Closing brace */
1049 1050
	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
1051 1052
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
1053 1054
	}

1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	/*
	 * 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.
	 */
	if (func_match) {
		ret = trace_seq_printf(s, "}\n");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	} else {
1066
		ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1067 1068 1069
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
1070

1071
	/* Overrun */
1072
	if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1073 1074
		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
					trace->overrun);
1075 1076
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
1077
	}
1078

1079 1080
	ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
			      cpu, pid, flags);
1081 1082 1083
	if (ret == TRACE_TYPE_PARTIAL_LINE)
		return TRACE_TYPE_PARTIAL_LINE;

1084 1085 1086
	return TRACE_TYPE_HANDLED;
}

1087
static enum print_line_t
1088 1089
print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
		    struct trace_iterator *iter, u32 flags)
1090
{
1091
	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1092
	struct fgraph_data *data = iter->private;
1093
	struct trace_event *event;
1094
	int depth = 0;
1095
	int ret;
1096 1097 1098
	int