This enables UBSAN for s390. We have to disable the null sanitizer
as s390 code does access memory via a null pointer (the prefix page).
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>