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// SPDX-License-Identifier: GPL-2.0
/*
* trace_boot.c
* Tracing kernel boot-time
*/
#define pr_fmt(fmt) "trace_boot: " fmt
#include <linux/ftrace.h>
#include <linux/init.h>
#include <linux/bootconfig.h>
#include "trace.h"
#define MAX_BUF_LEN 256
extern int trace_set_options(struct trace_array *tr, char *option);
extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
unsigned long size, int cpu_id);
static void __init
trace_boot_set_ftrace_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);
}
}
#ifdef CONFIG_EVENT_TRACING
extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
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);
}
}
#else
#define trace_boot_enable_events(tr, node) do {} while (0)
#endif
static void __init
trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
{
const char *p;
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 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;
trace_boot_set_ftrace_options(tr, trace_node);
trace_boot_enable_events(tr, trace_node);
trace_boot_enable_tracer(tr, trace_node);
return 0;
}
fs_initcall(trace_boot_init);
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