s390/hugetlb: fix prepare_hugepage_range() check for 2 GB hugepages

stable inclusion
from stable-v5.10.142
commit 0361d50e86c0a87feefa3d723deea9e4d5317341
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6CSFH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0361d50e86c0a87feefa3d723deea9e4d5317341



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commit 7c8d42fd upstream.

The alignment check in prepare_hugepage_range() is wrong for 2 GB
hugepages, it only checks for 1 MB hugepage alignment.

This can result in kernel crash in __unmap_hugepage_range() at the
BUG_ON(start & ~huge_page_mask(h)) alignment check, for mappings
created with MAP_FIXED at unaligned address.

Fix this by correctly handling multiple hugepage sizes, similar to the
generic version of prepare_hugepage_range().

Fixes: d08de8e2 ("s390/mm: add support for 2GB hugepages")
Cc: <stable@vger.kernel.org> # 4.8+
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
Reviewed-by: Zheng Zengkai <zhengzengkai@huawei.com>