linux/kernel/trace/trace_preemptirq.c
Sven Schnelle 73ac74c7d4 lockdep: fix order in trace_hardirqs_off_caller()
Switch order so that locking state is consistent even
if the IRQ tracer calls into lockdep again.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 10:08:07 +02:00

134 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* preemptoff and irqoff tracepoints
*
* Copyright (C) Joel Fernandes (Google) <joel@joelfernandes.org>
*/
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/kprobes.h>
#include "trace.h"
#define CREATE_TRACE_POINTS
#include <trace/events/preemptirq.h>
#ifdef CONFIG_TRACE_IRQFLAGS
/* Per-cpu variable to prevent redundant calls when IRQs already off */
static DEFINE_PER_CPU(int, tracing_irq_cpu);
/*
* Like trace_hardirqs_on() but without the lockdep invocation. This is
* used in the low level entry code where the ordering vs. RCU is important
* and lockdep uses a staged approach which splits the lockdep hardirq
* tracking into a RCU on and a RCU off section.
*/
void trace_hardirqs_on_prepare(void)
{
if (this_cpu_read(tracing_irq_cpu)) {
if (!in_nmi())
trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);
tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
this_cpu_write(tracing_irq_cpu, 0);
}
}
EXPORT_SYMBOL(trace_hardirqs_on_prepare);
NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
void trace_hardirqs_on(void)
{
if (this_cpu_read(tracing_irq_cpu)) {
if (!in_nmi())
trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
this_cpu_write(tracing_irq_cpu, 0);
}
lockdep_hardirqs_on_prepare(CALLER_ADDR0);
lockdep_hardirqs_on(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_on);
NOKPROBE_SYMBOL(trace_hardirqs_on);
/*
* Like trace_hardirqs_off() but without the lockdep invocation. This is
* used in the low level entry code where the ordering vs. RCU is important
* and lockdep uses a staged approach which splits the lockdep hardirq
* tracking into a RCU on and a RCU off section.
*/
void trace_hardirqs_off_finish(void)
{
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
if (!in_nmi())
trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);
}
}
EXPORT_SYMBOL(trace_hardirqs_off_finish);
NOKPROBE_SYMBOL(trace_hardirqs_off_finish);
void trace_hardirqs_off(void)
{
lockdep_hardirqs_off(CALLER_ADDR0);
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
if (!in_nmi())
trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
}
}
EXPORT_SYMBOL(trace_hardirqs_off);
NOKPROBE_SYMBOL(trace_hardirqs_off);
__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
{
if (this_cpu_read(tracing_irq_cpu)) {
if (!in_nmi())
trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
tracer_hardirqs_on(CALLER_ADDR0, caller_addr);
this_cpu_write(tracing_irq_cpu, 0);
}
lockdep_hardirqs_on_prepare(CALLER_ADDR0);
lockdep_hardirqs_on(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_on_caller);
NOKPROBE_SYMBOL(trace_hardirqs_on_caller);
__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
{
lockdep_hardirqs_off(CALLER_ADDR0);
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, caller_addr);
if (!in_nmi())
trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
}
}
EXPORT_SYMBOL(trace_hardirqs_off_caller);
NOKPROBE_SYMBOL(trace_hardirqs_off_caller);
#endif /* CONFIG_TRACE_IRQFLAGS */
#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
if (!in_nmi())
trace_preempt_enable_rcuidle(a0, a1);
tracer_preempt_on(a0, a1);
}
void trace_preempt_off(unsigned long a0, unsigned long a1)
{
if (!in_nmi())
trace_preempt_disable_rcuidle(a0, a1);
tracer_preempt_off(a0, a1);
}
#endif