Commit 17cc2b55 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

cpuidle: Ensure ct_cpuidle_enter() is always called from noinstr/__cpuidle 



Tracing (kprobes included) and other compiler instrumentation relies
on a normal kernel runtime. Therefore all functions that disable RCU
should be noinstr, as should all functions that are called while RCU
is disabled.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230112195542.212914195@infradead.org
parent 1c38b061

drivers/cpuidle/cpuidle.c

+28 −9
Original line number Diff line number Diff line
@@ -137,11 +137,13 @@ int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 
}



#ifdef CONFIG_SUSPEND

static void enter_s2idle_proper(struct cpuidle_driver *drv,

static noinstr void enter_s2idle_proper(struct cpuidle_driver *drv,

					 struct cpuidle_device *dev, int index)

{

	ktime_t time_start, time_end;

	struct cpuidle_state *target_state = &drv->states[index];

	ktime_t time_start, time_end;



	instrumentation_begin();



	time_start = ns_to_ktime(local_clock());
@@ -152,13 +154,18 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, 
	 * suspended is generally unsafe.

	 */

	stop_critical_timings();

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {

		ct_cpuidle_enter();

		/* Annotate away the indirect call */

		instrumentation_begin();

	}

	target_state->enter_s2idle(dev, drv, index);

	if (WARN_ON_ONCE(!irqs_disabled()))

		raw_local_irq_disable();

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {

		instrumentation_end();

		ct_cpuidle_exit();

	}

	tick_unfreeze();

	start_critical_timings();
@@ -166,6 +173,7 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, 


	dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start);

	dev->states_usage[index].s2idle_usage++;

	instrumentation_end();

}



/**
@@ -200,7 +208,8 @@ int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) 
 * @drv: cpuidle driver for this cpu

 * @index: index into the states table in @drv of the state to enter

 */

int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,

noinstr int cpuidle_enter_state(struct cpuidle_device *dev,

				 struct cpuidle_driver *drv,

				 int index)

{

	int entered_state;
@@ -209,6 +218,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, 
	bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP);

	ktime_t time_start, time_end;



	instrumentation_begin();



	/*

	 * Tell the time framework to switch to a broadcast timer because our

	 * local timer will be shut down.  If a local timer is used from another
@@ -235,15 +246,21 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, 
	time_start = ns_to_ktime(local_clock());



	stop_critical_timings();

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {

		ct_cpuidle_enter();

		/* Annotate away the indirect call */

		instrumentation_begin();

	}



	entered_state = target_state->enter(dev, drv, index);



	if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter))

		raw_local_irq_disable();



	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) {

		instrumentation_end();

		ct_cpuidle_exit();

	}

	start_critical_timings();



	sched_clock_idle_wakeup_event();
@@ -306,6 +323,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, 
		dev->states_usage[index].rejected++;

	}



	instrumentation_end();



	return entered_state;

}