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Commit | Line | Data |
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d13744cd FW |
1 | /* |
2 | * ring buffer based initcalls tracer | |
3 | * | |
4 | * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com> | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <linux/init.h> | |
9 | #include <linux/debugfs.h> | |
10 | #include <linux/ftrace.h> | |
5601020f | 11 | #include <linux/kallsyms.h> |
d13744cd FW |
12 | |
13 | #include "trace.h" | |
14 | ||
15 | static struct trace_array *boot_trace; | |
71566a0d | 16 | static bool pre_initcalls_finished; |
d13744cd | 17 | |
71566a0d FW |
18 | /* Tells the boot tracer that the pre_smp_initcalls are finished. |
19 | * So we are ready . | |
20 | * It doesn't enable sched events tracing however. | |
21 | * You have to call enable_boot_trace to do so. | |
22 | */ | |
d13744cd FW |
23 | void start_boot_trace(void) |
24 | { | |
71566a0d FW |
25 | pre_initcalls_finished = true; |
26 | } | |
27 | ||
28 | void enable_boot_trace(void) | |
29 | { | |
d7ad44b6 FW |
30 | if (pre_initcalls_finished) |
31 | tracing_start_cmdline_record(); | |
d13744cd FW |
32 | } |
33 | ||
71566a0d | 34 | void disable_boot_trace(void) |
d13744cd | 35 | { |
d7ad44b6 FW |
36 | if (pre_initcalls_finished) |
37 | tracing_stop_cmdline_record(); | |
d13744cd FW |
38 | } |
39 | ||
79a9d461 | 40 | static void reset_boot_trace(struct trace_array *tr) |
097d036a | 41 | { |
79a9d461 | 42 | sched_switch_trace.reset(tr); |
097d036a FW |
43 | } |
44 | ||
d13744cd FW |
45 | static void boot_trace_init(struct trace_array *tr) |
46 | { | |
47 | int cpu; | |
48 | boot_trace = tr; | |
49 | ||
d13744cd | 50 | for_each_cpu_mask(cpu, cpu_possible_map) |
3928a8a2 | 51 | tracing_reset(tr, cpu); |
d7ad44b6 FW |
52 | |
53 | sched_switch_trace.init(tr); | |
d13744cd FW |
54 | } |
55 | ||
56 | static void boot_trace_ctrl_update(struct trace_array *tr) | |
57 | { | |
58 | if (tr->ctrl) | |
71566a0d | 59 | enable_boot_trace(); |
d13744cd | 60 | else |
71566a0d | 61 | disable_boot_trace(); |
d13744cd FW |
62 | } |
63 | ||
9e9efffb | 64 | static enum print_line_t initcall_print_line(struct trace_iterator *iter) |
d13744cd | 65 | { |
9e9efffb | 66 | int ret; |
d13744cd | 67 | struct trace_entry *entry = iter->ent; |
777e208d SR |
68 | struct trace_boot *field = (struct trace_boot *)entry; |
69 | struct boot_trace *it = &field->initcall; | |
d13744cd | 70 | struct trace_seq *s = &iter->seq; |
cb5ab742 FW |
71 | struct timespec calltime = ktime_to_timespec(it->calltime); |
72 | struct timespec rettime = ktime_to_timespec(it->rettime); | |
d13744cd | 73 | |
9e9efffb | 74 | if (entry->type == TRACE_BOOT) { |
8a5d900c | 75 | ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n", |
cb5ab742 FW |
76 | calltime.tv_sec, |
77 | calltime.tv_nsec, | |
78 | it->func, it->caller); | |
79 | if (!ret) | |
9e9efffb | 80 | return TRACE_TYPE_PARTIAL_LINE; |
5601020f | 81 | |
8a5d900c | 82 | ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s " |
cb5ab742 FW |
83 | "returned %d after %lld msecs\n", |
84 | rettime.tv_sec, | |
85 | rettime.tv_nsec, | |
86 | it->func, it->result, it->duration); | |
5601020f | 87 | |
cb5ab742 FW |
88 | if (!ret) |
89 | return TRACE_TYPE_PARTIAL_LINE; | |
90 | return TRACE_TYPE_HANDLED; | |
9e9efffb FW |
91 | } |
92 | return TRACE_TYPE_UNHANDLED; | |
d13744cd FW |
93 | } |
94 | ||
95 | struct tracer boot_tracer __read_mostly = | |
96 | { | |
97 | .name = "initcall", | |
98 | .init = boot_trace_init, | |
097d036a | 99 | .reset = reset_boot_trace, |
d13744cd FW |
100 | .ctrl_update = boot_trace_ctrl_update, |
101 | .print_line = initcall_print_line, | |
102 | }; | |
103 | ||
5601020f | 104 | void trace_boot(struct boot_trace *it, initcall_t fn) |
d13744cd | 105 | { |
3928a8a2 | 106 | struct ring_buffer_event *event; |
777e208d | 107 | struct trace_boot *entry; |
d13744cd FW |
108 | struct trace_array_cpu *data; |
109 | unsigned long irq_flags; | |
110 | struct trace_array *tr = boot_trace; | |
111 | ||
71566a0d | 112 | if (!pre_initcalls_finished) |
d13744cd FW |
113 | return; |
114 | ||
5601020f FW |
115 | /* Get its name now since this function could |
116 | * disappear because it is in the .init section. | |
117 | */ | |
118 | sprint_symbol(it->func, (unsigned long)fn); | |
d13744cd FW |
119 | preempt_disable(); |
120 | data = tr->data[smp_processor_id()]; | |
121 | ||
3928a8a2 SR |
122 | event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), |
123 | &irq_flags); | |
124 | if (!event) | |
125 | goto out; | |
126 | entry = ring_buffer_event_data(event); | |
38697053 | 127 | tracing_generic_entry_update(&entry->ent, 0, 0); |
777e208d SR |
128 | entry->ent.type = TRACE_BOOT; |
129 | entry->initcall = *it; | |
3928a8a2 | 130 | ring_buffer_unlock_commit(tr->buffer, event, irq_flags); |
d13744cd | 131 | |
d13744cd FW |
132 | trace_wake_up(); |
133 | ||
3928a8a2 | 134 | out: |
d13744cd FW |
135 | preempt_enable(); |
136 | } |