kernel/trace/trace_boot.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * trace_boot.c
  * Tracing kernel boot-time
  */

 #define pr_fmt(fmt)	"trace_boot: " fmt

 #include <linux/bootconfig.h>
 #include <linux/cpumask.h>
 #include <linux/ftrace.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mutex.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/trace.h>
 #include <linux/trace_events.h>

 #include "trace.h"

 #define MAX_BUF_LEN 256

 static void __init
 trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
 {
 	struct xbc_node *anode;
 	const char *p;
 	char buf[MAX_BUF_LEN];
 	unsigned long v = 0;

 	/* Common ftrace options */
 	xbc_node_for_each_array_value(node, "options", anode, p) {
 		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
 			pr_err("String is too long: %s\n", p);
 			continue;
 		}

 		if (trace_set_options(tr, buf) < 0)
 			pr_err("Failed to set option: %s\n", buf);
 	}

 	p = xbc_node_find_value(node, "tracing_on", NULL);
 	if (p && *p != '\0') {
 		if (kstrtoul(p, 10, &v))
 			pr_err("Failed to set tracing on: %s\n", p);
 		if (v)
 			tracer_tracing_on(tr);
 		else
 			tracer_tracing_off(tr);
 	}

 	p = xbc_node_find_value(node, "trace_clock", NULL);
 	if (p && *p != '\0') {
 		if (tracing_set_clock(tr, p) < 0)
 			pr_err("Failed to set trace clock: %s\n", p);
 	}

 	p = xbc_node_find_value(node, "buffer_size", NULL);
 	if (p && *p != '\0') {
 		v = memparse(p, NULL);
 		if (v < PAGE_SIZE)
 			pr_err("Buffer size is too small: %s\n", p);
 		if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
 			pr_err("Failed to resize trace buffer to %s\n", p);
 	}

 	p = xbc_node_find_value(node, "cpumask", NULL);
 	if (p && *p != '\0') {
 		cpumask_var_t new_mask;

 		if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
 			if (cpumask_parse(p, new_mask) < 0 ||
 			    tracing_set_cpumask(tr, new_mask) < 0)
 				pr_err("Failed to set new CPU mask %s\n", p);
 			free_cpumask_var(new_mask);
 		}
 	}
 }

 #ifdef CONFIG_EVENT_TRACING
 static void __init
 trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
 {
 	struct xbc_node *anode;
 	char buf[MAX_BUF_LEN];
 	const char *p;

 	xbc_node_for_each_array_value(node, "events", anode, p) {
 		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
 			pr_err("String is too long: %s\n", p);
 			continue;
 		}

 		if (ftrace_set_clr_event(tr, buf, 1) < 0)
 			pr_err("Failed to enable event: %s\n", p);
 	}
 }

 #ifdef CONFIG_KPROBE_EVENTS
 static int __init
 trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
 {
 	struct dynevent_cmd cmd;
 	struct xbc_node *anode;
 	char buf[MAX_BUF_LEN];
 	const char *val;
 	int ret = 0;

 	xbc_node_for_each_array_value(node, "probes", anode, val) {
 		kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);

 		ret = kprobe_event_gen_cmd_start(&cmd, event, val);
 		if (ret) {
 			pr_err("Failed to generate probe: %s\n", buf);
 			break;
 		}

 		ret = kprobe_event_gen_cmd_end(&cmd);
 		if (ret) {
 			pr_err("Failed to add probe: %s\n", buf);
 			break;
 		}
 	}

 	return ret;
 }
 #else
 static inline int __init
 trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
 {
 	pr_err("Kprobe event is not supported.\n");
 	return -ENOTSUPP;
 }
 #endif

 #ifdef CONFIG_SYNTH_EVENTS
 static int __init
 trace_boot_add_synth_event(struct xbc_node *node, const char *event)
 {
 	struct dynevent_cmd cmd;
 	struct xbc_node *anode;
 	char buf[MAX_BUF_LEN];
 	const char *p;
 	int ret;

 	synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);

 	ret = synth_event_gen_cmd_start(&cmd, event, NULL);
 	if (ret)
 		return ret;

 	xbc_node_for_each_array_value(node, "fields", anode, p) {
 		ret = synth_event_add_field_str(&cmd, p);
 		if (ret)
 			return ret;
 	}

 	ret = synth_event_gen_cmd_end(&cmd);
 	if (ret < 0)
 		pr_err("Failed to add synthetic event: %s\n", buf);

 	return ret;
 }
 #else
 static inline int __init
 trace_boot_add_synth_event(struct xbc_node *node, const char *event)
 {
 	pr_err("Synthetic event is not supported.\n");
 	return -ENOTSUPP;
 }
 #endif

 static void __init
 trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
 			  struct xbc_node *enode)
 {
 	struct trace_event_file *file;
 	struct xbc_node *anode;
 	char buf[MAX_BUF_LEN];
 	const char *p, *group, *event;

 	group = xbc_node_get_data(gnode);
 	event = xbc_node_get_data(enode);

 	if (!strcmp(group, "kprobes"))
 		if (trace_boot_add_kprobe_event(enode, event) < 0)
 			return;
 	if (!strcmp(group, "synthetic"))
 		if (trace_boot_add_synth_event(enode, event) < 0)
 			return;

 	mutex_lock(&event_mutex);
 	file = find_event_file(tr, group, event);
 	if (!file) {
 		pr_err("Failed to find event: %s:%s\n", group, event);
 		goto out;
 	}

 	p = xbc_node_find_value(enode, "filter", NULL);
 	if (p && *p != '\0') {
 		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
 			pr_err("filter string is too long: %s\n", p);
 		else if (apply_event_filter(file, buf) < 0)
 			pr_err("Failed to apply filter: %s\n", buf);
 	}

 	xbc_node_for_each_array_value(enode, "actions", anode, p) {
 		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
 			pr_err("action string is too long: %s\n", p);
 		else if (trigger_process_regex(file, buf) < 0)
 			pr_err("Failed to apply an action: %s\n", buf);
 	}

 	if (xbc_node_find_value(enode, "enable", NULL)) {
 		if (trace_event_enable_disable(file, 1, 0) < 0)
 			pr_err("Failed to enable event node: %s:%s\n",
 				group, event);
 	}
 out:
 	mutex_unlock(&event_mutex);
 }

 static void __init
 trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
 {
 	struct xbc_node *gnode, *enode;

 	node = xbc_node_find_child(node, "event");
 	if (!node)
 		return;
 	/* per-event key starts with "event.GROUP.EVENT" */
 	xbc_node_for_each_child(node, gnode)
 		xbc_node_for_each_child(gnode, enode)
 			trace_boot_init_one_event(tr, gnode, enode);
 }
 #else
 #define trace_boot_enable_events(tr, node) do {} while (0)
 #define trace_boot_init_events(tr, node) do {} while (0)
 #endif

 #ifdef CONFIG_DYNAMIC_FTRACE
 static void __init
 trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
 {
 	struct xbc_node *anode;
 	const char *p;
 	char *q;

 	xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
 		q = kstrdup(p, GFP_KERNEL);
 		if (!q)
 			return;
 		if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
 			pr_err("Failed to add %s to ftrace filter\n", p);
 		else
 			ftrace_filter_param = true;
 		kfree(q);
 	}
 	xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
 		q = kstrdup(p, GFP_KERNEL);
 		if (!q)
 			return;
 		if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
 			pr_err("Failed to add %s to ftrace filter\n", p);
 		else
 			ftrace_filter_param = true;
 		kfree(q);
 	}
 }
 #else
 #define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
 #endif

 static void __init
 trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
 {
 	const char *p;

 	trace_boot_set_ftrace_filter(tr, node);

 	p = xbc_node_find_value(node, "tracer", NULL);
 	if (p && *p != '\0') {
 		if (tracing_set_tracer(tr, p) < 0)
 			pr_err("Failed to set given tracer: %s\n", p);
 	}

 	/* Since tracer can free snapshot buffer, allocate snapshot here.*/
 	if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
 		if (tracing_alloc_snapshot_instance(tr) < 0)
 			pr_err("Failed to allocate snapshot buffer\n");
 	}
 }

 static void __init
 trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
 {
 	trace_boot_set_instance_options(tr, node);
 	trace_boot_init_events(tr, node);
 	trace_boot_enable_events(tr, node);
 	trace_boot_enable_tracer(tr, node);
 }

 static void __init
 trace_boot_init_instances(struct xbc_node *node)
 {
 	struct xbc_node *inode;
 	struct trace_array *tr;
 	const char *p;

 	node = xbc_node_find_child(node, "instance");
 	if (!node)
 		return;

 	xbc_node_for_each_child(node, inode) {
 		p = xbc_node_get_data(inode);
 		if (!p || *p == '\0')
 			continue;

 		tr = trace_array_get_by_name(p);
 		if (!tr) {
 			pr_err("Failed to get trace instance %s\n", p);
 			continue;
 		}
 		trace_boot_init_one_instance(tr, inode);
 		trace_array_put(tr);
 	}
 }

 static int __init trace_boot_init(void)
 {
 	struct xbc_node *trace_node;
 	struct trace_array *tr;

 	trace_node = xbc_find_node("ftrace");
 	if (!trace_node)
 		return 0;

 	tr = top_trace_array();
 	if (!tr)
 		return 0;

 	/* Global trace array is also one instance */
 	trace_boot_init_one_instance(tr, trace_node);
 	trace_boot_init_instances(trace_node);

 	disable_tracing_selftest("running boot-time tracing");

 	return 0;
 }
 /*
  * Start tracing at the end of core-initcall, so that it starts tracing
  * from the beginning of postcore_initcall.
  */
 core_initcall_sync(trace_boot_init);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* trace_boot.c
	* Tracing kernel boot-time
	*/

	#define pr_fmt(fmt) "trace_boot: " fmt

	#include <linux/bootconfig.h>
	#include <linux/cpumask.h>
	#include <linux/ftrace.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/mutex.h>
	#include <linux/string.h>
	#include <linux/slab.h>
	#include <linux/trace.h>
	#include <linux/trace_events.h>

	#include "trace.h"

	#define MAX_BUF_LEN 256

	static void __init
	trace_boot_set_instance_options(struct trace_array tr, struct xbc_node node)
	{
	struct xbc_node *anode;
	const char *p;
	char buf[MAX_BUF_LEN];
	unsigned long v = 0;

	/* Common ftrace options */
	xbc_node_for_each_array_value(node, "options", anode, p) {
	if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
	pr_err("String is too long: %s\n", p);
	continue;
	}

	if (trace_set_options(tr, buf) < 0)
	pr_err("Failed to set option: %s\n", buf);
	}

	p = xbc_node_find_value(node, "tracing_on", NULL);
	if (p && *p != '\0') {
	if (kstrtoul(p, 10, &v))
	pr_err("Failed to set tracing on: %s\n", p);
	if (v)
	tracer_tracing_on(tr);
	else
	tracer_tracing_off(tr);
	}

	p = xbc_node_find_value(node, "trace_clock", NULL);
	if (p && *p != '\0') {
	if (tracing_set_clock(tr, p) < 0)
	pr_err("Failed to set trace clock: %s\n", p);
	}

	p = xbc_node_find_value(node, "buffer_size", NULL);
	if (p && *p != '\0') {
	v = memparse(p, NULL);
	if (v < PAGE_SIZE)
	pr_err("Buffer size is too small: %s\n", p);
	if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
	pr_err("Failed to resize trace buffer to %s\n", p);
	}

	p = xbc_node_find_value(node, "cpumask", NULL);
	if (p && *p != '\0') {
	cpumask_var_t new_mask;

	if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
	if (cpumask_parse(p, new_mask) < 0 \|\|
	tracing_set_cpumask(tr, new_mask) < 0)
	pr_err("Failed to set new CPU mask %s\n", p);
	free_cpumask_var(new_mask);
	}
	}
	}

	#ifdef CONFIG_EVENT_TRACING
	static void __init
	trace_boot_enable_events(struct trace_array tr, struct xbc_node node)
	{
	struct xbc_node *anode;
	char buf[MAX_BUF_LEN];
	const char *p;

	xbc_node_for_each_array_value(node, "events", anode, p) {
	if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
	pr_err("String is too long: %s\n", p);
	continue;
	}

	if (ftrace_set_clr_event(tr, buf, 1) < 0)
	pr_err("Failed to enable event: %s\n", p);
	}
	}

	#ifdef CONFIG_KPROBE_EVENTS
	static int __init
	trace_boot_add_kprobe_event(struct xbc_node node, const char event)
	{
	struct dynevent_cmd cmd;
	struct xbc_node *anode;
	char buf[MAX_BUF_LEN];
	const char *val;
	int ret = 0;

	xbc_node_for_each_array_value(node, "probes", anode, val) {
	kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);

	ret = kprobe_event_gen_cmd_start(&cmd, event, val);
	if (ret) {
	pr_err("Failed to generate probe: %s\n", buf);
	break;
	}

	ret = kprobe_event_gen_cmd_end(&cmd);
	if (ret) {
	pr_err("Failed to add probe: %s\n", buf);
	break;
	}
	}

	return ret;
	}
	#else
	static inline int __init
	trace_boot_add_kprobe_event(struct xbc_node node, const char event)
	{
	pr_err("Kprobe event is not supported.\n");
	return -ENOTSUPP;
	}
	#endif

	#ifdef CONFIG_SYNTH_EVENTS
	static int __init
	trace_boot_add_synth_event(struct xbc_node node, const char event)
	{
	struct dynevent_cmd cmd;
	struct xbc_node *anode;
	char buf[MAX_BUF_LEN];
	const char *p;
	int ret;

	synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);

	ret = synth_event_gen_cmd_start(&cmd, event, NULL);
	if (ret)
	return ret;

	xbc_node_for_each_array_value(node, "fields", anode, p) {
	ret = synth_event_add_field_str(&cmd, p);
	if (ret)
	return ret;
	}

	ret = synth_event_gen_cmd_end(&cmd);
	if (ret < 0)
	pr_err("Failed to add synthetic event: %s\n", buf);

	return ret;
	}
	#else
	static inline int __init
	trace_boot_add_synth_event(struct xbc_node node, const char event)
	{
	pr_err("Synthetic event is not supported.\n");
	return -ENOTSUPP;
	}
	#endif

	static void __init
	trace_boot_init_one_event(struct trace_array tr, struct xbc_node gnode,
	struct xbc_node *enode)
	{
	struct trace_event_file *file;
	struct xbc_node *anode;
	char buf[MAX_BUF_LEN];
	const char p, group, *event;

	group = xbc_node_get_data(gnode);
	event = xbc_node_get_data(enode);

	if (!strcmp(group, "kprobes"))
	if (trace_boot_add_kprobe_event(enode, event) < 0)
	return;
	if (!strcmp(group, "synthetic"))
	if (trace_boot_add_synth_event(enode, event) < 0)
	return;

	mutex_lock(&event_mutex);
	file = find_event_file(tr, group, event);
	if (!file) {
	pr_err("Failed to find event: %s:%s\n", group, event);
	goto out;
	}

	p = xbc_node_find_value(enode, "filter", NULL);
	if (p && *p != '\0') {
	if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
	pr_err("filter string is too long: %s\n", p);
	else if (apply_event_filter(file, buf) < 0)
	pr_err("Failed to apply filter: %s\n", buf);
	}

	xbc_node_for_each_array_value(enode, "actions", anode, p) {
	if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
	pr_err("action string is too long: %s\n", p);
	else if (trigger_process_regex(file, buf) < 0)
	pr_err("Failed to apply an action: %s\n", buf);
	}

	if (xbc_node_find_value(enode, "enable", NULL)) {
	if (trace_event_enable_disable(file, 1, 0) < 0)
	pr_err("Failed to enable event node: %s:%s\n",
	group, event);
	}
	out:
	mutex_unlock(&event_mutex);
	}

	static void __init
	trace_boot_init_events(struct trace_array tr, struct xbc_node node)
	{
	struct xbc_node gnode, enode;

	node = xbc_node_find_child(node, "event");
	if (!node)
	return;
	/* per-event key starts with "event.GROUP.EVENT" */
	xbc_node_for_each_child(node, gnode)
	xbc_node_for_each_child(gnode, enode)
	trace_boot_init_one_event(tr, gnode, enode);
	}
	#else
	#define trace_boot_enable_events(tr, node) do {} while (0)
	#define trace_boot_init_events(tr, node) do {} while (0)
	#endif

	#ifdef CONFIG_DYNAMIC_FTRACE
	static void __init
	trace_boot_set_ftrace_filter(struct trace_array tr, struct xbc_node node)
	{
	struct xbc_node *anode;
	const char *p;
	char *q;

	xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
	q = kstrdup(p, GFP_KERNEL);
	if (!q)
	return;
	if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
	pr_err("Failed to add %s to ftrace filter\n", p);
	else
	ftrace_filter_param = true;
	kfree(q);
	}
	xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
	q = kstrdup(p, GFP_KERNEL);
	if (!q)
	return;
	if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
	pr_err("Failed to add %s to ftrace filter\n", p);
	else
	ftrace_filter_param = true;
	kfree(q);
	}
	}
	#else
	#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
	#endif

	static void __init
	trace_boot_enable_tracer(struct trace_array tr, struct xbc_node node)
	{
	const char *p;

	trace_boot_set_ftrace_filter(tr, node);

	p = xbc_node_find_value(node, "tracer", NULL);
	if (p && *p != '\0') {
	if (tracing_set_tracer(tr, p) < 0)
	pr_err("Failed to set given tracer: %s\n", p);
	}

	/* Since tracer can free snapshot buffer, allocate snapshot here.*/
	if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
	if (tracing_alloc_snapshot_instance(tr) < 0)
	pr_err("Failed to allocate snapshot buffer\n");
	}
	}

	static void __init
	trace_boot_init_one_instance(struct trace_array tr, struct xbc_node node)
	{
	trace_boot_set_instance_options(tr, node);
	trace_boot_init_events(tr, node);
	trace_boot_enable_events(tr, node);
	trace_boot_enable_tracer(tr, node);
	}

	static void __init
	trace_boot_init_instances(struct xbc_node *node)
	{
	struct xbc_node *inode;
	struct trace_array *tr;
	const char *p;

	node = xbc_node_find_child(node, "instance");
	if (!node)
	return;

	xbc_node_for_each_child(node, inode) {
	p = xbc_node_get_data(inode);
	if (!p \|\| *p == '\0')
	continue;

	tr = trace_array_get_by_name(p);
	if (!tr) {
	pr_err("Failed to get trace instance %s\n", p);
	continue;
	}
	trace_boot_init_one_instance(tr, inode);
	trace_array_put(tr);
	}
	}

	static int __init trace_boot_init(void)
	{
	struct xbc_node *trace_node;
	struct trace_array *tr;

	trace_node = xbc_find_node("ftrace");
	if (!trace_node)
	return 0;

	tr = top_trace_array();
	if (!tr)
	return 0;

	/* Global trace array is also one instance */
	trace_boot_init_one_instance(tr, trace_node);
	trace_boot_init_instances(trace_node);

	disable_tracing_selftest("running boot-time tracing");

	return 0;
	}
	/*
	* Start tracing at the end of core-initcall, so that it starts tracing
	* from the beginning of postcore_initcall.
	*/
	core_initcall_sync(trace_boot_init);