// 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 __inittrace_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, "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_TRACINGstatic void __inittrace_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_EVENTSstatic int __inittrace_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)			break; 		ret = kprobe_event_gen_cmd_end(&cmd);		if (ret)			pr_err("Failed to add probe: %s\n", buf);	} 	return ret;}#elsestatic inline int __inittrace_boot_add_kprobe_event(struct xbc_node *node, const char *event){	pr_err("Kprobe event is not supported.\n");	return -ENOTSUPP;}#endif #ifdef CONFIG_HIST_TRIGGERSstatic int __inittrace_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;}#elsestatic inline int __inittrace_boot_add_synth_event(struct xbc_node *node, const char *event){	pr_err("Synthetic event is not supported.\n");	return -ENOTSUPP;}#endif static void __inittrace_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 __inittrace_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_FTRACEstatic void __inittrace_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 __inittrace_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);	}} static void __inittrace_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 __inittrace_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); 	return 0;} fs_initcall(trace_boot_init);