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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-12 16:16:29 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-12 16:16:29 -0800
commita0e5056e3b733ecb7d3089f8e1e6529525490ab9 (patch)
treebadb1c482b291cd942e8c7955246f8b044e900bb
parentf2ea97cbae25af2ec2ccfe892211c39147a8b4dc (diff)
parentd911e03d097bdc01363df5d81c43f69432eb785c (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux into akpm
Pull s390 regression fix from Martin Schwidefsky: "The recent fix for the s390 sched_clock() function uncovered yet another bug in s390_next_ktime which causes an endless loop in KVM. This regression should be fixed before v3.8. I keep the fingers crossed that this is the last one for v3.8." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/timer: avoid overflow when programming clock comparator
-rw-r--r--arch/s390/kernel/time.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index a5f4f5a..0aa98db 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -120,6 +120,9 @@ static int s390_next_ktime(ktime_t expires,
nsecs = ktime_to_ns(ktime_add(timespec_to_ktime(ts), expires));
do_div(nsecs, 125);
S390_lowcore.clock_comparator = sched_clock_base_cc + (nsecs << 9);
+ /* Program the maximum value if we have an overflow (== year 2042) */
+ if (unlikely(S390_lowcore.clock_comparator < sched_clock_base_cc))
+ S390_lowcore.clock_comparator = -1ULL;
set_clock_comparator(S390_lowcore.clock_comparator);
return 0;
}