From f065f41f48569122b5bcddbd1ba2354f7cc29fdc Mon Sep 17 00:00:00 2001 From: Barry Song <21cnbao@gmail.com> Date: Tue, 15 Dec 2009 16:45:34 -0800 Subject: [PATCH] timecompare: fix half-Y2K38 problem in timecompare_update while calculating offset ktime will overflow from 03:14:07 UTC on Tuesday, 19 January 2038, ktime_add() in timecompare_update() will overflow a half earlier. As a result, wrong offset will be gotten, then cause some strange problems. Signed-off-by: Barry Song <21cnbao@gmail.com> Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Patrick Ohly Cc: David S. Miller Cc: John Stultz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/time/timecompare.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c index 96ff643a5a59..12f5c55090be 100644 --- a/kernel/time/timecompare.c +++ b/kernel/time/timecompare.c @@ -89,7 +89,7 @@ int timecompare_offset(struct timecompare *sync, * source time */ sample.offset = - ktime_to_ns(ktime_add(end, start)) / 2 - + (ktime_to_ns(end) + ktime_to_ns(start)) / 2 - ts; /* simple insertion sort based on duration */