path: root/kernel/trace/trace_functions_graph.c

// 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"

/* 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-