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 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -125,6 +125,7 @@ config S390
        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