[mirror_ubuntu-bionic-kernel.git] / kernel / trace / trace_functions_graph.c

/*
 *
 * Function graph tracer.
 * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
 * 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>
#include <linux/fs.h>

#include "trace.h"

#define TRACE_GRAPH_INDENT	2

/* Flag options */
#define TRACE_GRAPH_PRINT_OVERRUN	0x1
#define TRACE_GRAPH_PRINT_CPU		0x2
#define TRACE_GRAPH_PRINT_OVERHEAD	0x4

static struct tracer_opt trace_opts[] = {
	/* Display overruns ? */
	{ 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) },
	{ } /* Empty entry */
};

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

/* pid on the last trace processed */
static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };

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

	for_each_online_cpu(cpu)
		tracing_reset(tr, cpu);

	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 inline int log10_cpu(int nb)
{
	if (nb / 100)
		return 3;
	if (nb / 10)
		return 2;
	return 1;
}

static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
	int i;
	int ret;
	int log10_this = log10_cpu(cpu);
	int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));


	for (i = 0; i < log10_all - log10_this; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
	ret = trace_seq_printf(s, "%d) ", cpu);
	if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	return TRACE_TYPE_HANDLED;
}


/* If the pid changed since the last trace, output this event */
static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
{
	char *comm;

	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
		return 1;

	last_pid[cpu] = pid;
	comm = trace_find_cmdline(pid);

	return trace_seq_printf(s, "\n------------8<---------- thread %s-%d"
				    " ------------8<----------\n\n",
				    cpu, comm, pid);
}

static bool
trace_branch_is_leaf(struct trace_iterator *iter,
		struct ftrace_graph_ent_entry *curr)
{
	struct ring_buffer_iter *ring_iter;
	struct ring_buffer_event *event;
	struct ftrace_graph_ret_entry *next;

	ring_iter = iter->buffer_iter[iter->cpu];

	if (!ring_iter)
		return false;

	event = ring_buffer_iter_peek(ring_iter, NULL);

	if (!event)
		return false;

	next = ring_buffer_event_data(event);

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

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

	return true;
}


static inline int
print_graph_duration(unsigned long long duration, struct trace_seq *s)
{
	unsigned long nsecs_rem = do_div(duration, 1000);
	return trace_seq_printf(s, "%4llu.%3lu us | ", duration, nsecs_rem);
}

/* Signal a overhead of time execution to the output */
static int
print_graph_overhead(unsigned long long duration, struct trace_seq *s)
{
	/* 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, "  ");
}

/* 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 trace_seq *s)
{
	struct ftrace_graph_ret_entry *ret_entry;
	struct ftrace_graph_ret *graph_ret;
	struct ring_buffer_event *event;
	struct ftrace_graph_ent *call;
	unsigned long long duration;
	int ret;
	int i;

	event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
	ret_entry = ring_buffer_event_data(event);
	graph_ret = &ret_entry->ret;
	call = &entry->graph_ent;
	duration = graph_ret->rettime - graph_ret->calltime;

	/* Must not exceed 8 characters: 9999.999 us */
	if (duration > 10000000ULL)
		duration = 9999999ULL;

	/* Overhead */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
		ret = print_graph_overhead(duration, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Duration */
	ret = print_graph_duration(duration, s);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

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

	ret = seq_print_ip_sym(s, call->func, 0);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

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

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
			struct trace_seq *s)
{
	int i;
	int ret;
	struct ftrace_graph_ent *call = &entry->graph_ent;

	/* No overhead */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
		ret = trace_seq_printf(s, "  ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* No time */
	ret = trace_seq_printf(s, "        |     ");

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

	ret = seq_print_ip_sym(s, call->func, 0);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	ret = trace_seq_printf(s, "() {\n");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
			struct trace_iterator *iter, int cpu)
{
	int ret;
	struct trace_entry *ent = iter->ent;

	/* Pid */
	if (!verif_pid(s, ent->pid, cpu))
		return TRACE_TYPE_PARTIAL_LINE;

	/* Cpu */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
		ret = print_graph_cpu(s, cpu);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	if (trace_branch_is_leaf(iter, field))
		return print_graph_entry_leaf(iter, field, s);
	else
		return print_graph_entry_nested(field, s);

}

static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
		   struct trace_entry *ent, int cpu)
{
	int i;
	int ret;
	unsigned long long duration = trace->rettime - trace->calltime;

	/* Must not exceed 8 characters: xxxx.yyy us */
	if (duration > 10000000ULL)
		duration = 9999999ULL;

	/* Pid */
	if (!verif_pid(s, ent->pid, cpu))
		return TRACE_TYPE_PARTIAL_LINE;

	/* Cpu */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
		ret = print_graph_cpu(s, cpu);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Overhead */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
		ret = print_graph_overhead(duration, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Duration */
	ret = print_graph_duration(duration, s);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

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

	ret = trace_seq_printf(s, "}\n");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Overrun */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
					trace->overrun);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
	return TRACE_TYPE_HANDLED;
}

enum print_line_t
print_graph_function(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry = iter->ent;

	switch (entry->type) {
	case TRACE_GRAPH_ENT: {
		struct ftrace_graph_ent_entry *field;
		trace_assign_type(field, entry);
		return print_graph_entry(field, s, iter,
					 iter->cpu);
	}
	case TRACE_GRAPH_RET: {
		struct ftrace_graph_ret_entry *field;
		trace_assign_type(field, entry);
		return print_graph_return(&field->ret, s, entry, iter->cpu);
	}
	default:
		return TRACE_TYPE_UNHANDLED;
	}
}

static struct tracer graph_trace __read_mostly = {
	.name	     = "function_graph",
	.init	     = graph_trace_init,
	.reset	     = graph_trace_reset,
	.print_line = print_graph_function,
	.flags		= &tracer_flags,
};

static __init int init_graph_trace(void)
{
	return register_tracer(&graph_trace);
}

device_initcall(init_graph_trace);
Commit	Line	Data
fb52607a FW	1	/*
	2	*
	3	* Function graph tracer.
	4	* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
	5	* Mostly borrowed from function tracer which
	6	* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
	7	*
	8	*/
	9	#include <linux/debugfs.h>
	10	#include <linux/uaccess.h>
	11	#include <linux/ftrace.h>
	12	#include <linux/fs.h>
	13
	14	#include "trace.h"
	15
287b6e68	16	#define TRACE_GRAPH_INDENT 2
fb52607a	17
1a056155	18	/* Flag options */
fb52607a	19	#define TRACE_GRAPH_PRINT_OVERRUN 0x1
1a056155 FW	20	#define TRACE_GRAPH_PRINT_CPU 0x2
	21	#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
	22
fb52607a	23	static struct tracer_opt trace_opts[] = {
1a056155 FW	24	/* Display overruns ? */
	25	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
	26	/* Display CPU ? */
	27	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
	28	/* Display Overhead ? */
	29	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
fb52607a FW	30	{ } /* Empty entry */
	31	};
	32
	33	static struct tracer_flags tracer_flags = {
1a056155 FW	34	/* Don't display overruns by default */
1a056155 FW	35	.val = TRACE_GRAPH_PRINT_CPU \| TRACE_GRAPH_PRINT_OVERHEAD,
fb52607a FW	36	.opts = trace_opts
	37	};
	38
287b6e68	39	/* pid on the last trace processed */
437f24fb	40	static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
fb52607a FW	41
	42	static int graph_trace_init(struct trace_array *tr)
	43	{
660c7f9b SR	44	int cpu, ret;
660c7f9b SR	45
fb52607a FW	46	for_each_online_cpu(cpu)
	47	tracing_reset(tr, cpu);
	48
660c7f9b	49	ret = register_ftrace_graph(&trace_graph_return,
287b6e68	50	&trace_graph_entry);
660c7f9b SR	51	if (ret)
	52	return ret;
	53	tracing_start_cmdline_record();
	54
	55	return 0;
fb52607a FW	56	}
	57
	58	static void graph_trace_reset(struct trace_array *tr)
	59	{
660c7f9b SR	60	tracing_stop_cmdline_record();
660c7f9b SR	61	unregister_ftrace_graph();
fb52607a FW	62	}
fb52607a FW	63
1a056155 FW	64	static inline int log10_cpu(int nb)
	65	{
	66	if (nb / 100)
	67	return 3;
	68	if (nb / 10)
	69	return 2;
	70	return 1;
	71	}
	72
	73	static enum print_line_t
	74	print_graph_cpu(struct trace_seq *s, int cpu)
	75	{
	76	int i;
	77	int ret;
	78	int log10_this = log10_cpu(cpu);
	79	int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));
	80
	81
	82	for (i = 0; i < log10_all - log10_this; i++) {
	83	ret = trace_seq_printf(s, " ");
	84	if (!ret)
	85	return TRACE_TYPE_PARTIAL_LINE;
	86	}
	87	ret = trace_seq_printf(s, "%d) ", cpu);
	88	if (!ret)
	89	return TRACE_TYPE_PARTIAL_LINE;
	90	return TRACE_TYPE_HANDLED;
	91	}
	92
	93
287b6e68	94	/* If the pid changed since the last trace, output this event */
437f24fb	95	static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
287b6e68	96	{
660c7f9b SR	97	char *comm;
660c7f9b SR	98
437f24fb	99	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
287b6e68	100	return 1;
fb52607a	101
437f24fb	102	last_pid[cpu] = pid;
660c7f9b SR	103	comm = trace_find_cmdline(pid);
660c7f9b SR	104
1a056155	105	return trace_seq_printf(s, "\n------------8<---------- thread %s-%d"
287b6e68	106	" ------------8<----------\n\n",
437f24fb	107	cpu, comm, pid);
287b6e68 FW	108	}
287b6e68 FW	109
83a8df61 FW	110	static bool
	111	trace_branch_is_leaf(struct trace_iterator *iter,
	112	struct ftrace_graph_ent_entry *curr)
	113	{
	114	struct ring_buffer_iter *ring_iter;
	115	struct ring_buffer_event *event;
	116	struct ftrace_graph_ret_entry *next;
	117
	118	ring_iter = iter->buffer_iter[iter->cpu];
	119
	120	if (!ring_iter)
	121	return false;
	122
1a056155	123	event = ring_buffer_iter_peek(ring_iter, NULL);
83a8df61 FW	124
	125	if (!event)
	126	return false;
	127
	128	next = ring_buffer_event_data(event);
	129
	130	if (next->ent.type != TRACE_GRAPH_RET)
	131	return false;
	132
	133	if (curr->ent.pid != next->ent.pid \|\|
	134	curr->graph_ent.func != next->ret.func)
	135	return false;
	136
	137	return true;
	138	}
	139
	140
	141	static inline int
	142	print_graph_duration(unsigned long long duration, struct trace_seq *s)
	143	{
	144	unsigned long nsecs_rem = do_div(duration, 1000);
1a056155	145	return trace_seq_printf(s, "%4llu.%3lu us \| ", duration, nsecs_rem);
83a8df61 FW	146	}
	147
	148	/* Signal a overhead of time execution to the output */
	149	static int
	150	print_graph_overhead(unsigned long long duration, struct trace_seq *s)
	151	{
	152	/* Duration exceeded 100 msecs */
	153	if (duration > 100000ULL)
	154	return trace_seq_printf(s, "! ");
	155
	156	/* Duration exceeded 10 msecs */
	157	if (duration > 10000ULL)
	158	return trace_seq_printf(s, "+ ");
	159
	160	return trace_seq_printf(s, " ");
	161	}
	162
	163	/* Case of a leaf function on its call entry */
287b6e68	164	static enum print_line_t
83a8df61 FW	165	print_graph_entry_leaf(struct trace_iterator *iter,
83a8df61 FW	166	struct ftrace_graph_ent_entry entry, struct trace_seq s)
fb52607a	167	{
83a8df61 FW	168	struct ftrace_graph_ret_entry *ret_entry;
	169	struct ftrace_graph_ret *graph_ret;
	170	struct ring_buffer_event *event;
	171	struct ftrace_graph_ent *call;
	172	unsigned long long duration;
fb52607a	173	int ret;
1a056155	174	int i;
fb52607a	175
83a8df61 FW	176	event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
	177	ret_entry = ring_buffer_event_data(event);
	178	graph_ret = &ret_entry->ret;
	179	call = &entry->graph_ent;
	180	duration = graph_ret->rettime - graph_ret->calltime;
	181
1a056155 FW	182	/* Must not exceed 8 characters: 9999.999 us */
	183	if (duration > 10000000ULL)
	184	duration = 9999999ULL;
	185
83a8df61	186	/* Overhead */
1a056155 FW	187	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
	188	ret = print_graph_overhead(duration, s);
	189	if (!ret)
	190	return TRACE_TYPE_PARTIAL_LINE;
	191	}
	192
	193	/* Duration */
	194	ret = print_graph_duration(duration, s);
83a8df61	195	if (!ret)
437f24fb SR	196	return TRACE_TYPE_PARTIAL_LINE;
437f24fb SR	197
83a8df61 FW	198	/* Function */
	199	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
	200	ret = trace_seq_printf(s, " ");
	201	if (!ret)
	202	return TRACE_TYPE_PARTIAL_LINE;
	203	}
	204
	205	ret = seq_print_ip_sym(s, call->func, 0);
	206	if (!ret)
	207	return TRACE_TYPE_PARTIAL_LINE;
	208
1a056155	209	ret = trace_seq_printf(s, "();\n");
83a8df61 FW	210	if (!ret)
	211	return TRACE_TYPE_PARTIAL_LINE;
	212
	213	return TRACE_TYPE_HANDLED;
	214	}
	215
	216	static enum print_line_t
	217	print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
	218	struct trace_seq *s)
	219	{
	220	int i;
	221	int ret;
	222	struct ftrace_graph_ent *call = &entry->graph_ent;
	223
	224	/* No overhead */
1a056155 FW	225	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
	226	ret = trace_seq_printf(s, " ");
	227	if (!ret)
	228	return TRACE_TYPE_PARTIAL_LINE;
	229	}
	230
	231	/* No time */
	232	ret = trace_seq_printf(s, " \| ");
83a8df61 FW	233
83a8df61 FW	234	/* Function */
287b6e68 FW	235	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
287b6e68 FW	236	ret = trace_seq_printf(s, " ");
fb52607a FW	237	if (!ret)
fb52607a FW	238	return TRACE_TYPE_PARTIAL_LINE;
287b6e68 FW	239	}
	240
	241	ret = seq_print_ip_sym(s, call->func, 0);
	242	if (!ret)
	243	return TRACE_TYPE_PARTIAL_LINE;
	244
1a056155	245	ret = trace_seq_printf(s, "() {\n");
83a8df61 FW	246	if (!ret)
	247	return TRACE_TYPE_PARTIAL_LINE;
	248
287b6e68 FW	249	return TRACE_TYPE_HANDLED;
	250	}
	251
83a8df61 FW	252	static enum print_line_t
	253	print_graph_entry(struct ftrace_graph_ent_entry field, struct trace_seq s,
	254	struct trace_iterator *iter, int cpu)
	255	{
	256	int ret;
	257	struct trace_entry *ent = iter->ent;
	258
1a056155	259	/* Pid */
83a8df61 FW	260	if (!verif_pid(s, ent->pid, cpu))
	261	return TRACE_TYPE_PARTIAL_LINE;
	262
1a056155 FW	263	/* Cpu */
	264	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
	265	ret = print_graph_cpu(s, cpu);
	266	if (!ret)
	267	return TRACE_TYPE_PARTIAL_LINE;
	268	}
83a8df61 FW	269
	270	if (trace_branch_is_leaf(iter, field))
	271	return print_graph_entry_leaf(iter, field, s);
	272	else
	273	return print_graph_entry_nested(field, s);
	274
	275	}
	276
287b6e68 FW	277	static enum print_line_t
287b6e68 FW	278	print_graph_return(struct ftrace_graph_ret trace, struct trace_seq s,
437f24fb	279	struct trace_entry *ent, int cpu)
287b6e68 FW	280	{
	281	int i;
	282	int ret;
83a8df61	283	unsigned long long duration = trace->rettime - trace->calltime;
287b6e68	284
1a056155 FW	285	/* Must not exceed 8 characters: xxxx.yyy us */
	286	if (duration > 10000000ULL)
	287	duration = 9999999ULL;
	288
83a8df61	289	/* Pid */
437f24fb SR	290	if (!verif_pid(s, ent->pid, cpu))
	291	return TRACE_TYPE_PARTIAL_LINE;
	292
83a8df61	293	/* Cpu */
1a056155 FW	294	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
	295	ret = print_graph_cpu(s, cpu);
	296	if (!ret)
	297	return TRACE_TYPE_PARTIAL_LINE;
	298	}
fb52607a	299
83a8df61	300	/* Overhead */
1a056155 FW	301	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
	302	ret = print_graph_overhead(duration, s);
	303	if (!ret)
	304	return TRACE_TYPE_PARTIAL_LINE;
	305	}
	306
	307	/* Duration */
	308	ret = print_graph_duration(duration, s);
83a8df61 FW	309	if (!ret)
	310	return TRACE_TYPE_PARTIAL_LINE;
	311
	312	/* Closing brace */
287b6e68 FW	313	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
287b6e68 FW	314	ret = trace_seq_printf(s, " ");
fb52607a FW	315	if (!ret)
fb52607a FW	316	return TRACE_TYPE_PARTIAL_LINE;
287b6e68 FW	317	}
287b6e68 FW	318
1a056155	319	ret = trace_seq_printf(s, "}\n");
287b6e68 FW	320	if (!ret)
287b6e68 FW	321	return TRACE_TYPE_PARTIAL_LINE;
fb52607a	322
83a8df61	323	/* Overrun */
287b6e68 FW	324	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
	325	ret = trace_seq_printf(s, " (Overruns: %lu)\n",
	326	trace->overrun);
fb52607a FW	327	if (!ret)
fb52607a FW	328	return TRACE_TYPE_PARTIAL_LINE;
287b6e68 FW	329	}
	330	return TRACE_TYPE_HANDLED;
	331	}
	332
	333	enum print_line_t
	334	print_graph_function(struct trace_iterator *iter)
	335	{
	336	struct trace_seq *s = &iter->seq;
	337	struct trace_entry *entry = iter->ent;
fb52607a	338
287b6e68 FW	339	switch (entry->type) {
	340	case TRACE_GRAPH_ENT: {
	341	struct ftrace_graph_ent_entry *field;
	342	trace_assign_type(field, entry);
83a8df61	343	return print_graph_entry(field, s, iter,
437f24fb	344	iter->cpu);
287b6e68 FW	345	}
	346	case TRACE_GRAPH_RET: {
	347	struct ftrace_graph_ret_entry *field;
	348	trace_assign_type(field, entry);
437f24fb	349	return print_graph_return(&field->ret, s, entry, iter->cpu);
287b6e68 FW	350	}
	351	default:
	352	return TRACE_TYPE_UNHANDLED;
fb52607a	353	}
fb52607a FW	354	}
	355
	356	static struct tracer graph_trace __read_mostly = {
83a8df61	357	.name = "function_graph",
fb52607a FW	358	.init = graph_trace_init,
	359	.reset = graph_trace_reset,
	360	.print_line = print_graph_function,
	361	.flags = &tracer_flags,
	362	};
	363
	364	static __init int init_graph_trace(void)
	365	{
	366	return register_tracer(&graph_trace);
	367	}
	368
	369	device_initcall(init_graph_trace);