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/*
* ring buffer based initcalls tracer
*
* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
*
*/
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
#include <linux/kallsyms.h>
#include "trace.h"
static struct trace_array *boot_trace;
static bool pre_initcalls_finished;
/* Tells the boot tracer that the pre_smp_initcalls are finished.
* So we are ready .
* It doesn't enable sched events tracing however.
* You have to call enable_boot_trace to do so.
*/
void start_boot_trace(void)
{
pre_initcalls_finished = true;
}
void enable_boot_trace(void)
{
if (pre_initcalls_finished)
tracing_start_sched_switch_record();
}
void disable_boot_trace(void)
{
if (pre_initcalls_finished)
tracing_stop_sched_switch_record();
}
static void reset_boot_trace(struct trace_array *tr)
{
int cpu;
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
tracing_reset(tr, cpu);
}
static void boot_trace_init(struct trace_array *tr)
{
int cpu;
boot_trace = tr;
for_each_cpu_mask(cpu, cpu_possible_map)
tracing_reset(tr, cpu);
tracing_sched_switch_assign_trace(tr);
}
static void boot_trace_ctrl_update(struct trace_array *tr)
{
if (tr->ctrl)
enable_boot_trace();
else
disable_boot_trace();
}
static enum print_line_t initcall_print_line(struct trace_iterator *iter)
{
int ret;
struct trace_entry *entry = iter->ent;
struct trace_boot *field = (struct trace_boot *)entry;
struct boot_trace *it = &field->initcall;
struct trace_seq *s = &iter->seq;
struct timespec calltime = ktime_to_timespec(it->calltime);
struct timespec rettime = ktime_to_timespec(it->rettime);
if (entry->type == TRACE_BOOT) {
ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n",
calltime.tv_sec,
calltime.tv_nsec,
it->func, it->caller);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
"returned %d after %lld msecs\n",
rettime.tv_sec,
rettime.tv_nsec,
it->func, it->result, it->duration);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
return TRACE_TYPE_UNHANDLED;
}
struct tracer boot_tracer __read_mostly =
{
.name = "initcall",
.init = boot_trace_init,
.reset = reset_boot_trace,
.ctrl_update = boot_trace_ctrl_update,
.print_line = initcall_print_line,
};
void trace_boot(struct boot_trace *it, initcall_t fn)
{
struct ring_buffer_event *event;
struct trace_boot *entry;
struct trace_array_cpu *data;
unsigned long irq_flags;
struct trace_array *tr = boot_trace;
if (!pre_initcalls_finished)
return;
/* Get its name now since this function could
* disappear because it is in the .init section.
*/
sprint_symbol(it->func, (unsigned long)fn);
preempt_disable();
data = tr->data[smp_processor_id()];
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
&irq_flags);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
tracing_generic_entry_update(&entry->ent, 0, 0);
entry->ent.type = TRACE_BOOT;
entry->initcall = *it;
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
trace_wake_up();
out:
preempt_enable();
}
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