Add a separate "[vvar]" mapping for the vdso datapage, since it
doesn't need to be executable or COW-able.
This is actually the s390 implementation of commit 8715493852
("arm64: vdso: put vdso datapage in a separate vma")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>