187 lines
4.0 KiB
C
187 lines
4.0 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 bool pre_initcalls_finished;
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/* Tells the boot tracer that the pre_smp_initcalls are finished.
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* So we are ready .
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* It doesn't enable sched events tracing however.
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* You have to call enable_boot_trace to do so.
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*/
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void start_boot_trace(void)
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{
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pre_initcalls_finished = true;
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}
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void enable_boot_trace(void)
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{
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if (pre_initcalls_finished)
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tracing_start_sched_switch_record();
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}
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void disable_boot_trace(void)
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{
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if (pre_initcalls_finished)
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tracing_stop_sched_switch_record();
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}
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static int 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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for_each_cpu(cpu, cpu_possible_mask)
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tracing_reset(tr, cpu);
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tracing_sched_switch_assign_trace(tr);
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return 0;
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}
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static enum print_line_t
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initcall_call_print_line(struct trace_iterator *iter)
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{
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struct trace_entry *entry = iter->ent;
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struct trace_seq *s = &iter->seq;
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struct trace_boot_call *field;
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struct boot_trace_call *call;
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u64 ts;
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unsigned long nsec_rem;
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int ret;
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trace_assign_type(field, entry);
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call = &field->boot_call;
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ts = iter->ts;
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nsec_rem = do_div(ts, 1000000000);
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ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n",
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(unsigned long)ts, nsec_rem, call->func, call->caller);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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else
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return TRACE_TYPE_HANDLED;
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}
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static enum print_line_t
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initcall_ret_print_line(struct trace_iterator *iter)
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{
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struct trace_entry *entry = iter->ent;
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struct trace_seq *s = &iter->seq;
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struct trace_boot_ret *field;
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struct boot_trace_ret *init_ret;
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u64 ts;
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unsigned long nsec_rem;
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int ret;
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trace_assign_type(field, entry);
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init_ret = &field->boot_ret;
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ts = iter->ts;
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nsec_rem = do_div(ts, 1000000000);
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ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
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"returned %d after %llu msecs\n",
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(unsigned long) ts,
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nsec_rem,
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init_ret->func, init_ret->result, init_ret->duration);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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else
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return TRACE_TYPE_HANDLED;
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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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struct trace_entry *entry = iter->ent;
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switch (entry->type) {
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case TRACE_BOOT_CALL:
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return initcall_call_print_line(iter);
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case TRACE_BOOT_RET:
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return initcall_ret_print_line(iter);
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default:
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return TRACE_TYPE_UNHANDLED;
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}
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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 = tracing_reset_online_cpus,
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.print_line = initcall_print_line,
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};
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void trace_boot_call(struct boot_trace_call *bt, initcall_t fn)
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{
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struct ring_buffer_event *event;
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struct trace_boot_call *entry;
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unsigned long irq_flags;
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struct trace_array *tr = boot_trace;
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if (!pre_initcalls_finished)
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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(bt->func, (unsigned long)fn);
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preempt_disable();
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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_CALL;
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entry->boot_call = *bt;
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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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void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn)
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{
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struct ring_buffer_event *event;
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struct trace_boot_ret *entry;
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unsigned long irq_flags;
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struct trace_array *tr = boot_trace;
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if (!pre_initcalls_finished)
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return;
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sprint_symbol(bt->func, (unsigned long)fn);
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preempt_disable();
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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_RET;
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entry->boot_ret = *bt;
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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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