127 lines
2.7 KiB
C
127 lines
2.7 KiB
C
/*
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* ring buffer based initcalls tracer
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*
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* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
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*
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*/
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#include <linux/init.h>
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#include <linux/debugfs.h>
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#include <linux/ftrace.h>
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#include <linux/kallsyms.h>
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#include "trace.h"
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static struct trace_array *boot_trace;
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static int trace_boot_enabled;
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/* Should be started after do_pre_smp_initcalls() in init/main.c */
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void start_boot_trace(void)
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{
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trace_boot_enabled = 1;
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}
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void stop_boot_trace(void)
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{
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trace_boot_enabled = 0;
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}
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void reset_boot_trace(struct trace_array *tr)
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{
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stop_boot_trace();
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}
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static void boot_trace_init(struct trace_array *tr)
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{
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int cpu;
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boot_trace = tr;
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trace_boot_enabled = 0;
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for_each_cpu_mask(cpu, cpu_possible_map)
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tracing_reset(tr, cpu);
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}
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static void boot_trace_ctrl_update(struct trace_array *tr)
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{
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if (tr->ctrl)
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start_boot_trace();
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else
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stop_boot_trace();
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}
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static enum print_line_t initcall_print_line(struct trace_iterator *iter)
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{
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int ret;
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struct trace_entry *entry = iter->ent;
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struct trace_boot *field = (struct trace_boot *)entry;
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struct boot_trace *it = &field->initcall;
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struct trace_seq *s = &iter->seq;
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struct timespec calltime = ktime_to_timespec(it->calltime);
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struct timespec rettime = ktime_to_timespec(it->rettime);
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if (entry->type == TRACE_BOOT) {
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ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n",
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calltime.tv_sec,
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calltime.tv_nsec,
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it->func, it->caller);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
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"returned %d after %lld msecs\n",
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rettime.tv_sec,
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rettime.tv_nsec,
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it->func, it->result, it->duration);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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return TRACE_TYPE_HANDLED;
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}
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return TRACE_TYPE_UNHANDLED;
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}
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struct tracer boot_tracer __read_mostly =
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{
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.name = "initcall",
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.init = boot_trace_init,
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.reset = reset_boot_trace,
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.ctrl_update = boot_trace_ctrl_update,
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.print_line = initcall_print_line,
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};
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void trace_boot(struct boot_trace *it, initcall_t fn)
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{
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struct ring_buffer_event *event;
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struct trace_boot *entry;
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struct trace_array_cpu *data;
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unsigned long irq_flags;
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struct trace_array *tr = boot_trace;
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if (!trace_boot_enabled)
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return;
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/* Get its name now since this function could
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* disappear because it is in the .init section.
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*/
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sprint_symbol(it->func, (unsigned long)fn);
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preempt_disable();
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data = tr->data[smp_processor_id()];
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event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
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&irq_flags);
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if (!event)
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goto out;
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entry = ring_buffer_event_data(event);
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tracing_generic_entry_update(&entry->ent, 0, 0);
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entry->ent.type = TRACE_BOOT;
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entry->initcall = *it;
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ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
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trace_wake_up();
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out:
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preempt_enable();
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}
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