trace_functions_graph.c 34.7 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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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);
}

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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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		size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);

		snprintf(nsecs_str, slen, "%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;
	}
715 716 717 718 719 720 721 722 723 724 725
	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;
726 727 728 729 730

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

731
	return TRACE_TYPE_HANDLED;
732 733 734
}

/* Case of a leaf function on its call entry */
735
static enum print_line_t
736
print_graph_entry_leaf(struct trace_iterator *iter,
737
		struct ftrace_graph_ent_entry *entry,
738 739
		struct ftrace_graph_ret_entry *ret_entry,
		struct trace_seq *s, u32 flags)
740
{
741
	struct fgraph_data *data = iter->private;
742 743 744
	struct ftrace_graph_ret *graph_ret;
	struct ftrace_graph_ent *call;
	unsigned long long duration;
745
	int ret;
746
	int i;
747

748 749 750 751
	graph_ret = &ret_entry->ret;
	call = &entry->graph_ent;
	duration = graph_ret->rettime - graph_ret->calltime;

752
	if (data) {
753
		struct fgraph_cpu_data *cpu_data;
754
		int cpu = iter->cpu;
755 756

		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
757 758 759 760 761 762

		/*
		 * Comments display at + 1 to depth. Since
		 * this is a leaf function, keep the comments
		 * equal to this depth.
		 */
763 764 765 766 767
		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;
768 769
	}

770
	/* Overhead */
771
	ret = print_graph_overhead(duration, s, flags);
772 773
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
774 775

	/* Duration */
776
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
777 778 779 780
		ret = print_graph_duration(duration, s);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
781

782 783 784 785 786 787 788
	/* Function */
	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

789
	ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
790 791 792 793 794 795 796
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
797 798
print_graph_entry_nested(struct trace_iterator *iter,
			 struct ftrace_graph_ent_entry *entry,
799
			 struct trace_seq *s, int cpu, u32 flags)
800 801
{
	struct ftrace_graph_ent *call = &entry->graph_ent;
802 803 804 805 806
	struct fgraph_data *data = iter->private;
	int ret;
	int i;

	if (data) {
807
		struct fgraph_cpu_data *cpu_data;
808 809
		int cpu = iter->cpu;

810 811 812 813 814 815
		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;
816
	}
817 818

	/* No overhead */
819
	ret = print_graph_overhead(-1, s, flags);
820 821
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
822

823
	/* No time */
824
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
825 826 827 828 829
		ret = trace_seq_printf(s, "            |  ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

830
	/* Function */
831 832
	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
833 834
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
835 836
	}

837
	ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
838 839 840
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

841 842 843 844 845
	/*
	 * we already consumed the current entry to check the next one
	 * and see if this is a leaf.
	 */
	return TRACE_TYPE_NO_CONSUME;
846 847
}

848
static enum print_line_t
849
print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
850
		     int type, unsigned long addr, u32 flags)
851
{
852
	struct fgraph_data *data = iter->private;
853
	struct trace_entry *ent = iter->ent;
854 855
	int cpu = iter->cpu;
	int ret;
856

857
	/* Pid */
858
	if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
859 860
		return TRACE_TYPE_PARTIAL_LINE;

861 862
	if (type) {
		/* Interrupt */
863
		ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
864 865 866
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
867

868
	/* Absolute time */
869
	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
870 871 872 873 874
		ret = print_graph_abs_time(iter->ts, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

875
	/* Cpu */
876
	if (flags & TRACE_GRAPH_PRINT_CPU) {
877
		ret = print_graph_cpu(s, cpu);
878 879 880 881 882
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Proc */
883
	if (flags & TRACE_GRAPH_PRINT_PROC) {
884
		ret = print_graph_proc(s, ent->pid);
885 886 887 888
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;

		ret = trace_seq_printf(s, " | ");
889 890 891
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
892

893 894 895 896 897 898 899
	/* 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;
	}

900 901 902
	return 0;
}

903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918
/*
 * 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;
919
	int *depth_irq;
920 921
	struct fgraph_data *data = iter->private;

922 923 924 925 926 927 928
	/*
	 * 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))
929 930
		return 0;

931 932
	depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964
	/*
	 * 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;
965
	int *depth_irq;
966 967
	struct fgraph_data *data = iter->private;

968 969 970 971 972 973 974
	/*
	 * 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))
975 976
		return 0;

977 978
	depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);

979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004
	/*
	 * 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;
}

1005 1006
static enum print_line_t
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1007
			struct trace_iterator *iter, u32 flags)
1008
{
1009
	struct fgraph_data *data = iter->private;
1010 1011
	struct ftrace_graph_ent *call = &field->graph_ent;
	struct ftrace_graph_ret_entry *leaf_ret;
1012 1013
	static enum print_line_t ret;
	int cpu = iter->cpu;
1014

1015 1016 1017
	if (check_irq_entry(iter, flags, call->func, call->depth))
		return TRACE_TYPE_HANDLED;

1018
	if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
1019 1020
		return TRACE_TYPE_PARTIAL_LINE;

1021 1022
	leaf_ret = get_return_for_leaf(iter, field);
	if (leaf_ret)
1023
		ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1024
	else
1025
		ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1026

1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039
	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;
1040 1041
}

1042 1043
static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1044 1045
		   struct trace_entry *ent, struct trace_iterator *iter,
		   u32 flags)
1046
{
1047
	unsigned long long duration = trace->rettime - trace->calltime;
1048 1049 1050
	struct fgraph_data *data = iter->private;
	pid_t pid = ent->pid;
	int cpu = iter->cpu;
1051
	int func_match = 1;
1052 1053 1054
	int ret;
	int i;

1055 1056 1057
	if (check_irq_return(iter, flags, trace->depth))
		return TRACE_TYPE_HANDLED;

1058
	if (data) {
1059 1060 1061 1062
		struct fgraph_cpu_data *cpu_data;
		int cpu = iter->cpu;

		cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1063 1064 1065 1066 1067 1068

		/*
		 * 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.
		 */
1069 1070 1071 1072 1073 1074 1075
		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;
		}
1076
	}
1077

1078
	if (print_graph_prologue(iter, s, 0, 0, flags))
1079 1080
		return TRACE_TYPE_PARTIAL_LINE;

1081
	/* Overhead */
1082
	ret = print_graph_overhead(duration, s, flags);
1083 1084
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;
1085 1086

	/* Duration */
1087
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
1088 1089 1090 1091
		ret = print_graph_duration(duration, s);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}
1092 1093

	/* Closing brace */
1094 1095
	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
1096 1097
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
1098 1099
	}

1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110
	/*
	 * 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 {
1111
		ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1112 1113 1114
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
1115

1116
	/* Overrun */
1117
	if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1118 1119
		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
					trace->overrun);
1120 1121
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
1122
	}
1123

1124 1125
	ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
			      cpu, pid, flags);
1126 1127 1128
	if (ret == TRACE_TYPE_PARTIAL_LINE)
		return TRACE_TYPE_PARTIAL_LINE;

1129 1130 1131
	return TRACE_TYPE_HANDLED;
}

1132
static enum print_line_t
1133 1134
print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
		    struct trace_iterator *iter, u32 flags)
1135
{
1136
	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1137
	struct fgraph_data *data = iter->private;
1138
	struct trace_event *event;
1139
	int depth = 0;
1140
	int ret;
1141 1142 1143
	int i;

	if (data)
1144
		depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1145

1146
	if (print_graph_prologue(iter, s, 0, 0, flags))
1147 1148
		return TRACE_TYPE_PARTIAL_LINE;

1149
	/* No overhead */
1150
	ret = print_graph_overhead(-1, s, flags);
1151 1152 1153 1154
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* No time */
1155
	if (flags & TRACE_GRAPH_PRINT_DURATION) {
1156
		ret = trace_seq_printf(s, "            |  ");
1157 1158 1159 1160 1161
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Indentation */
1162 1163
	if (depth > 0)
		for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1164 1165 1166 1167 1168 1169
			ret = trace_seq_printf(s, " ");
			if (!ret)
				return TRACE_TYPE_PARTIAL_LINE;
		}

	/* The comment */
1170 1171 1172 1173
	ret = trace_seq_printf(s, "/* ");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189
	switch (iter->ent->type) {
	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;

1190
		ret = event->funcs->trace(iter, sym_flags, event);
1191 1192 1193
		if (ret != TRACE_TYPE_HANDLED)
			return ret;
	}
1194

1195 1196 1197 1198 1199 1200
	/* Strip ending newline */
	if (s->buffer[s->len - 1] == '\n') {
		s->buffer[s->len - 1] = '\0';
		s->len--;
	}

1201 1202 1203 1204 1205 1206 1207 1208
	ret = trace_seq_printf(s, " */\n");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}


1209
enum print_line_t
1210
__print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1211
{
1212 1213
	struct ftrace_graph_ent_entry *field;
	struct fgraph_data *data = iter->private;
1214
	struct trace_entry *entry = iter->ent;
1215
	struct trace_seq *s = &iter->seq;
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230
	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;
1231
		ret = print_graph_entry(field, s, iter, flags);
1232 1233 1234 1235 1236 1237 1238
		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;
	}
1239

1240 1241
	switch (entry->type) {
	case TRACE_GRAPH_ENT: {
1242 1243 1244 1245 1246 1247
		/*
		 * 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.
		 */
1248
		struct ftrace_graph_ent_entry saved;
1249