Commit 11385539 authored by Johannes Berg's avatar Johannes Berg Committed by Richard Weinberger
Browse files

um: time-travel: Correct time event IRQ delivery 



Lockdep (on 5.10-rc) points out that we're delivering IRQs while IRQs
are not even enabled, which clearly shouldn't happen. Defer the time
event IRQ delivery until they actually are enabled.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent cae20ba0

arch/um/include/shared/common-offsets.h

+3 −0
Original line number Diff line number Diff line
@@ -40,3 +40,6 @@ DEFINE(UML_CONFIG_UML_X86, CONFIG_UML_X86); 
#ifdef CONFIG_64BIT

DEFINE(UML_CONFIG_64BIT, CONFIG_64BIT);

#endif

#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT

DEFINE(UML_CONFIG_UML_TIME_TRAVEL_SUPPORT, CONFIG_UML_TIME_TRAVEL_SUPPORT);

#endif

arch/um/include/shared/os.h

+3 −0
Original line number Diff line number Diff line
@@ -342,4 +342,7 @@ extern void unblock_signals_trace(void); 
extern void um_trace_signals_on(void);

extern void um_trace_signals_off(void);



/* time-travel */

extern void deliver_time_travel_irqs(void);



#endif

arch/um/kernel/time.c

+38 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ static bool time_travel_start_set; 
static unsigned long long time_travel_start;

static unsigned long long time_travel_time;

static LIST_HEAD(time_travel_events);

static LIST_HEAD(time_travel_irqs);

static unsigned long long time_travel_timer_interval;

static unsigned long long time_travel_next_event;

static struct time_travel_event time_travel_timer_event;
@@ -324,6 +325,35 @@ void time_travel_periodic_timer(struct time_travel_event *e) 
	deliver_alarm();

}



void deliver_time_travel_irqs(void)

{

	struct time_travel_event *e;

	unsigned long flags;



	/*

	 * Don't do anything for most cases. Note that because here we have

	 * to disable IRQs (and re-enable later) we'll actually recurse at

	 * the end of the function, so this is strictly necessary.

	 */

	if (likely(list_empty(&time_travel_irqs)))

		return;



	local_irq_save(flags);

	irq_enter();

	while ((e = list_first_entry_or_null(&time_travel_irqs,

					     struct time_travel_event,

					     list))) {

		WARN(e->time != time_travel_time,

		     "time moved from %lld to %lld before IRQ delivery\n",

		     time_travel_time, e->time);

		list_del(&e->list);

		e->pending = false;

		e->fn(e);

	}

	irq_exit();

	local_irq_restore(flags);

}



static void time_travel_deliver_event(struct time_travel_event *e)

{

	if (e == &time_travel_timer_event) {
@@ -332,6 +362,14 @@ static void time_travel_deliver_event(struct time_travel_event *e) 
		 * by itself, so must handle it specially here

		 */

		e->fn(e);

	} else if (irqs_disabled()) {

		list_add_tail(&e->list, &time_travel_irqs);

		/*

		 * set pending again, it was set to false when the

		 * event was deleted from the original list, but

		 * now it's still pending until we deliver the IRQ.

		 */

		e->pending = true;

	} else {

		unsigned long flags;

arch/um/os-Linux/signal.c

+3 −0
Original line number Diff line number Diff line
@@ -271,6 +271,9 @@ void unblock_signals(void) 
		return;



	signals_enabled = 1;

#ifdef UML_CONFIG_UML_TIME_TRAVEL_SUPPORT

	deliver_time_travel_irqs();

#endif



	/*

	 * We loop because the IRQ handler returns with interrupts off.  So,

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