s390/time: select CLOCKSOURCE_VALIDATE_LAST_CYCLE
The value returned by read_tod_clock() will overflow on September 17th 2042.
To avoid that system time jumps back select CLOCKSOURCE_VALIDATE_LAST_CYCLE
which enables a sanity check in order to prevent negative "delta" values.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 0df33cf..d95d323 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -125,6 +125,7 @@
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN
select HAVE_ARCH_KASAN_VMALLOC
+ select CLOCKSOURCE_VALIDATE_LAST_CYCLE
select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_SOFT_DIRTY