b8333d22a3
We have debug infrastructure built on top of preempt/irq disable/enable
events. This requires modifications to the kernel tracing code. Since
this is not feasible with GKI, we started with registering to the
existing preemptirq trace events. However the performance of wide
variety of use cases are regressed as the rate of preemptirq events
is super high and generic trace events are slow.
Since GKI allows optimized trace events via restricted trace hooks,
add the same for preemptirq event.
This patch reverts commit d94fa9dcf5, which itself was a revert, effectively bringing back the original
change (Ic8d3cdd1c1aa6a9267d0b755694fedffa2ea8e36)
Bug: 174541725
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Sai Harshini Nimmala <quic_snimmala@quicinc.com>
Change-Id: I24a3cdf17abf41e7512438516b2cfe561802c666
[jstultz: Reworked commit message]
Signed-off-by: John Stultz <jstultz@google.com>
137 lines
3.6 KiB
C
137 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* preemptoff and irqoff tracepoints
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*
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* Copyright (C) Joel Fernandes (Google) <joel@joelfernandes.org>
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*/
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#include <linux/kallsyms.h>
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#include <linux/uaccess.h>
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#include <linux/module.h>
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#include <linux/ftrace.h>
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#include <linux/kprobes.h>
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#include "trace.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/preemptirq.h>
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#undef CREATE_TRACE_POINTS
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#include <trace/hooks/preemptirq.h>
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/*
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* Use regular trace points on architectures that implement noinstr
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* tooling: these calls will only happen with RCU enabled, which can
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* use a regular tracepoint.
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*
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* On older architectures, use the rcuidle tracing methods (which
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* aren't NMI-safe - so exclude NMI contexts):
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*/
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#ifdef CONFIG_ARCH_WANTS_NO_INSTR
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#define trace(point) trace_##point
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#else
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#define trace(point) if (!in_nmi()) trace_##point##_rcuidle
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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/* Per-cpu variable to prevent redundant calls when IRQs already off */
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static DEFINE_PER_CPU(int, tracing_irq_cpu);
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/*
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* Like trace_hardirqs_on() but without the lockdep invocation. This is
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* used in the low level entry code where the ordering vs. RCU is important
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* and lockdep uses a staged approach which splits the lockdep hardirq
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* tracking into a RCU on and a RCU off section.
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*/
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void trace_hardirqs_on_prepare(void)
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{
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if (this_cpu_read(tracing_irq_cpu)) {
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trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);
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if (!in_nmi()) {
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trace_android_rvh_irqs_enable(CALLER_ADDR0,
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CALLER_ADDR1);
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}
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tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
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this_cpu_write(tracing_irq_cpu, 0);
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}
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}
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EXPORT_SYMBOL(trace_hardirqs_on_prepare);
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NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
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void trace_hardirqs_on(void)
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{
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if (this_cpu_read(tracing_irq_cpu)) {
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trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);
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if (!in_nmi()) {
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trace_android_rvh_irqs_enable(CALLER_ADDR0,
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CALLER_ADDR1);
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}
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tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
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this_cpu_write(tracing_irq_cpu, 0);
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}
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lockdep_hardirqs_on_prepare();
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lockdep_hardirqs_on(CALLER_ADDR0);
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}
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EXPORT_SYMBOL(trace_hardirqs_on);
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NOKPROBE_SYMBOL(trace_hardirqs_on);
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/*
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* Like trace_hardirqs_off() but without the lockdep invocation. This is
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* used in the low level entry code where the ordering vs. RCU is important
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* and lockdep uses a staged approach which splits the lockdep hardirq
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* tracking into a RCU on and a RCU off section.
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*/
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void trace_hardirqs_off_finish(void)
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{
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if (!this_cpu_read(tracing_irq_cpu)) {
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this_cpu_write(tracing_irq_cpu, 1);
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tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
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trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);
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if (!in_nmi()) {
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trace_android_rvh_irqs_disable(CALLER_ADDR0,
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CALLER_ADDR1);
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}
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}
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}
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EXPORT_SYMBOL(trace_hardirqs_off_finish);
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NOKPROBE_SYMBOL(trace_hardirqs_off_finish);
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void trace_hardirqs_off(void)
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{
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lockdep_hardirqs_off(CALLER_ADDR0);
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if (!this_cpu_read(tracing_irq_cpu)) {
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this_cpu_write(tracing_irq_cpu, 1);
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tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
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trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);
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if (!in_nmi()) {
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trace_android_rvh_irqs_disable(CALLER_ADDR0,
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CALLER_ADDR1);
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}
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}
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}
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EXPORT_SYMBOL(trace_hardirqs_off);
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NOKPROBE_SYMBOL(trace_hardirqs_off);
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#endif /* CONFIG_TRACE_IRQFLAGS */
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#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
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void trace_preempt_on(unsigned long a0, unsigned long a1)
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{
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trace(preempt_enable)(a0, a1);
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if (!in_nmi()) {
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trace_android_rvh_preempt_enable(a0, a1);
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}
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tracer_preempt_on(a0, a1);
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}
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void trace_preempt_off(unsigned long a0, unsigned long a1)
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{
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trace(preempt_disable)(a0, a1);
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if (!in_nmi()) {
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trace_android_rvh_preempt_disable(a0, a1);
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}
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tracer_preempt_off(a0, a1);
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}
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#endif
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