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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/*
* 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"
#include "trace_output.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 (boot_trace && pre_initcalls_finished)
tracing_start_sched_switch_record();
}
void disable_boot_trace(void)
{
if (boot_trace && pre_initcalls_finished)
tracing_stop_sched_switch_record();
}
static int boot_trace_init(struct trace_array *tr)
{
int cpu;
boot_trace = tr;
if (!tr)
return 0;
for_each_cpu(cpu, cpu_possible_mask)
tracing_reset(tr, cpu);
tracing_sched_switch_assign_trace(tr);
return 0;
}
static enum print_line_t
initcall_call_print_line(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
struct trace_seq *s = &iter->seq;
struct trace_boot_call *field;
struct boot_trace_call *call;
u64 ts;
unsigned long nsec_rem;
int ret;
trace_assign_type(field, entry);
call = &field->boot_call;
ts = iter->ts;
nsec_rem = do_div(ts, 1000000000);
ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n",
(unsigned long)ts, nsec_rem, call->func, call->caller);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
else
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
initcall_ret_print_line(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
struct trace_seq *s = &iter->seq;
struct trace_boot_ret *field;
struct boot_trace_ret *init_ret;
u64 ts;
unsigned long nsec_rem;
int ret;
trace_assign_type(field, entry);
init_ret = &field->boot_ret;
ts = iter->ts;
nsec_rem = do_div(ts, 1000000000);
ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
"returned %d after %llu msecs\n",
(unsigned long) ts,
nsec_rem,
init_ret->func, init_ret->result, init_ret->duration);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
else
return TRACE_TYPE_HANDLED;
}
static enum print_line_t initcall_print_line(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
switch (entry->type) {
case TRACE_BOOT_CALL:
return initcall_call_print_line(iter);
case TRACE_BOOT_RET:
return initcall_ret_print_line(iter);
default:
return TRACE_TYPE_UNHANDLED;
}
}
struct tracer boot_tracer __read_mostly =
{
.name = "initcall",
.init = boot_trace_init,
.reset = tracing_reset_online_cpus,
.print_line = initcall_print_line,
};
void trace_boot_call(struct boot_trace_call *bt, initcall_t fn)
{
struct ring_buffer_event *event;
struct trace_boot_call *entry;
struct trace_array *tr = boot_trace;
if (!tr || !pre_initcalls_finished)
return;
/* Get its name now since this function could
* disappear because it is in the .init section.
*/
sprint_symbol(bt->func, (unsigned long)fn);
preempt_disable();
event = trace_buffer_lock_reserve(tr, TRACE_BOOT_CALL,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->boot_call = *bt;
trace_buffer_unlock_commit(tr, event, 0, 0);
out:
preempt_enable();
}
void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn)
{
struct ring_buffer_event *event;
struct trace_boot_ret *entry;
struct trace_array *tr = boot_trace;
if (!tr || !pre_initcalls_finished)
return;
sprint_symbol(bt->func, (unsigned long)fn);
preempt_disable();
event = trace_buffer_lock_reserve(tr, TRACE_BOOT_RET,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->boot_ret = *bt;
trace_buffer_unlock_commit(tr, event, 0, 0);
out:
preempt_enable();
}
|
