1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/*
* 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 "trace.h"
static struct trace_array *boot_trace;
static int trace_boot_enabled;
/* Should be started after do_pre_smp_initcalls() in init/main.c */
void start_boot_trace(void)
{
trace_boot_enabled = 1;
}
void stop_boot_trace(struct trace_array *tr)
{
trace_boot_enabled = 0;
}
static void boot_trace_init(struct trace_array *tr)
{
int cpu;
boot_trace = tr;
trace_boot_enabled = 0;
for_each_cpu_mask(cpu, cpu_possible_map)
tracing_reset(tr, cpu);
}
static void boot_trace_ctrl_update(struct trace_array *tr)
{
if (tr->ctrl)
start_boot_trace();
else
stop_boot_trace(tr);
}
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;
if (entry->type == TRACE_BOOT) {
ret = trace_seq_printf(s, "%pF called from %i "
"returned %d after %lld msecs\n",
it->func, it->caller, it->result,
it->duration);
if (ret)
return TRACE_TYPE_HANDLED;
else
return TRACE_TYPE_PARTIAL_LINE;
}
return TRACE_TYPE_UNHANDLED;
}
struct tracer boot_tracer __read_mostly =
{
.name = "initcall",
.init = boot_trace_init,
.reset = stop_boot_trace,
.ctrl_update = boot_trace_ctrl_update,
.print_line = initcall_print_line,
};
void trace_boot(struct boot_trace *it)
{
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 (!trace_boot_enabled)
return;
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();
}
|
