2 * ring buffer based initcalls tracer
4 * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
8 #include <linux/init.h>
9 #include <linux/debugfs.h>
10 #include <linux/ftrace.h>
11 #include <linux/kallsyms.h>
15 static struct trace_array
*boot_trace
;
16 static int trace_boot_enabled
;
19 /* Should be started after do_pre_smp_initcalls() in init/main.c */
20 void start_boot_trace(void)
22 trace_boot_enabled
= 1;
25 void stop_boot_trace(void)
27 trace_boot_enabled
= 0;
30 void reset_boot_trace(struct trace_array
*tr
)
35 static void boot_trace_init(struct trace_array
*tr
)
40 trace_boot_enabled
= 0;
42 for_each_cpu_mask(cpu
, cpu_possible_map
)
43 tracing_reset(tr
, cpu
);
46 static void boot_trace_ctrl_update(struct trace_array
*tr
)
54 static enum print_line_t
initcall_print_line(struct trace_iterator
*iter
)
57 struct trace_entry
*entry
= iter
->ent
;
58 struct trace_boot
*field
= (struct trace_boot
*)entry
;
59 struct boot_trace
*it
= &field
->initcall
;
60 struct trace_seq
*s
= &iter
->seq
;
61 struct timespec calltime
= ktime_to_timespec(it
->calltime
);
62 struct timespec rettime
= ktime_to_timespec(it
->rettime
);
64 if (entry
->type
== TRACE_BOOT
) {
65 ret
= trace_seq_printf(s
, "[%5ld.%09ld] calling %s @ %i\n",
68 it
->func
, it
->caller
);
70 return TRACE_TYPE_PARTIAL_LINE
;
72 ret
= trace_seq_printf(s
, "[%5ld.%09ld] initcall %s "
73 "returned %d after %lld msecs\n",
76 it
->func
, it
->result
, it
->duration
);
79 return TRACE_TYPE_PARTIAL_LINE
;
80 return TRACE_TYPE_HANDLED
;
82 return TRACE_TYPE_UNHANDLED
;
85 struct tracer boot_tracer __read_mostly
=
88 .init
= boot_trace_init
,
89 .reset
= reset_boot_trace
,
90 .ctrl_update
= boot_trace_ctrl_update
,
91 .print_line
= initcall_print_line
,
94 void trace_boot(struct boot_trace
*it
, initcall_t fn
)
96 struct ring_buffer_event
*event
;
97 struct trace_boot
*entry
;
98 struct trace_array_cpu
*data
;
99 unsigned long irq_flags
;
100 struct trace_array
*tr
= boot_trace
;
102 if (!trace_boot_enabled
)
105 /* Get its name now since this function could
106 * disappear because it is in the .init section.
108 sprint_symbol(it
->func
, (unsigned long)fn
);
110 data
= tr
->data
[smp_processor_id()];
112 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
116 entry
= ring_buffer_event_data(event
);
117 tracing_generic_entry_update(&entry
->ent
, 0, 0);
118 entry
->ent
.type
= TRACE_BOOT
;
119 entry
->initcall
= *it
;
120 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);