// 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 <linux/hardirq.h>#include "trace.h" #define CREATE_TRACE_POINTS#include <trace/events/preemptirq.h> /* * Use regular trace points on architectures that implement noinstr * tooling: these calls will only happen with RCU enabled, which can * use a regular tracepoint. * * On older architectures, RCU may not be watching in idle. In that * case, wake up RCU to watch while calling the tracepoint. These * aren't NMI-safe - so exclude NMI contexts: */#ifdef CONFIG_ARCH_WANTS_NO_INSTR#define trace(point, args)	trace_##point(args)#else#define trace(point, args)					\	do {							\		if (__trace_##point##_enabled()) {		\			bool exit_rcu = false;			\			if (in_nmi())				\				break;				\			if (!IS_ENABLED(CONFIG_TINY_RCU) &&	\			    is_idle_task(current)) {		\				ct_irq_enter();			\				exit_rcu = true;		\			}					\			trace_##point(args);			\			if (exit_rcu)				\				ct_irq_exit();			\		}						\	} while (0)#endif #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)) {		trace(irq_enable, TP_ARGS(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)) {		trace(irq_enable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));		tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);		this_cpu_write(tracing_irq_cpu, 0);	} 	lockdep_hardirqs_on_prepare();	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);		trace(irq_disable, TP_ARGS(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);		trace(irq_disable, TP_ARGS(CALLER_ADDR0, CALLER_ADDR1));	}}EXPORT_SYMBOL(trace_hardirqs_off);NOKPROBE_SYMBOL(trace_hardirqs_off);#endif /* CONFIG_TRACE_IRQFLAGS */ #ifdef CONFIG_TRACE_PREEMPT_TOGGLE void trace_preempt_on(unsigned long a0, unsigned long a1){	trace(preempt_enable, TP_ARGS(a0, a1));	tracer_preempt_on(a0, a1);} void trace_preempt_off(unsigned long a0, unsigned long a1){	trace(preempt_disable, TP_ARGS(a0, a1));	tracer_preempt_off(a0, a1);}#endif