um: fix time travel mode

Unfortunately, my build fix for when time travel mode isn't
enabled broke time travel mode, because I forgot that we need
to use the timer time after the timer has been marked disabled,
and thus need to leave the time stored instead of zeroing it.

Fix that by splitting the inline into two, so we can call only
the _mode() one in the relevant code path.

Fixes: b482e48d29 ("um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORT")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/include/shared/timer-internal.h

@@ -34,10 +34,13 @@ static inline void time_travel_set_time(unsigned long long ns)
 	time_travel_time = ns;
 }
 
-static inline void time_travel_set_timer(enum time_travel_timer_mode mode,
-					 unsigned long long expiry)
+static inline void time_travel_set_timer_mode(enum time_travel_timer_mode mode)
 {
 	time_travel_timer_mode = mode;
+}
+
+static inline void time_travel_set_timer_expiry(unsigned long long expiry)
+{
 	time_travel_timer_expiry = expiry;
 }
 #else
@@ -50,8 +53,11 @@ static inline void time_travel_set_time(unsigned long long ns)
 {
 }
 
-static inline void time_travel_set_timer(enum time_travel_timer_mode mode,
-					 unsigned long long expiry)
+static inline void time_travel_set_timer_mode(enum time_travel_timer_mode mode)
+{
+}
+
+static inline void time_travel_set_timer_expiry(unsigned long long expiry)
 {
 }
 

arch/um/kernel/process.c

@@ -213,7 +213,7 @@ static void time_travel_sleep(unsigned long long duration)
 	if (time_travel_timer_mode != TT_TMR_DISABLED ||
 	    time_travel_timer_expiry < next) {
 		if (time_travel_timer_mode == TT_TMR_ONESHOT)
-			time_travel_set_timer(TT_TMR_DISABLED, 0);
+			time_travel_set_timer_mode(TT_TMR_DISABLED);
 		/*
 		 * time_travel_time will be adjusted in the timer
 		 * IRQ handler so it works even when the signal

arch/um/kernel/time.c

@@ -50,7 +50,7 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 static int itimer_shutdown(struct clock_event_device *evt)
 {
 	if (time_travel_mode != TT_MODE_OFF)
-		time_travel_set_timer(TT_TMR_DISABLED, 0);
+		time_travel_set_timer_mode(TT_TMR_DISABLED);
 
 	if (time_travel_mode != TT_MODE_INFCPU)
 		os_timer_disable();
@@ -62,9 +62,10 @@ static int itimer_set_periodic(struct clock_event_device *evt)
 {
 	unsigned long long interval = NSEC_PER_SEC / HZ;
 
-	if (time_travel_mode != TT_MODE_OFF)
-		time_travel_set_timer(TT_TMR_PERIODIC,
-				      time_travel_time + interval);
+	if (time_travel_mode != TT_MODE_OFF) {
+		time_travel_set_timer_mode(TT_TMR_PERIODIC);
+		time_travel_set_timer_expiry(time_travel_time + interval);
+	}
 
 	if (time_travel_mode != TT_MODE_INFCPU)
 		os_timer_set_interval(interval);
@@ -77,9 +78,10 @@ static int itimer_next_event(unsigned long delta,
 {
 	delta += 1;
 
-	if (time_travel_mode != TT_MODE_OFF)
-		time_travel_set_timer(TT_TMR_ONESHOT,
-				      time_travel_time + delta);
+	if (time_travel_mode != TT_MODE_OFF) {
+		time_travel_set_timer_mode(TT_TMR_ONESHOT);
+		time_travel_set_timer_expiry(time_travel_time + delta);
+	}
 
 	if (time_travel_mode != TT_MODE_INFCPU)
 		return os_timer_one_shot(delta);