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

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commit 7c8d42fdf1 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: d08de8e2d8 ("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>
This commit is contained in:
Gerald Schaefer 2022-08-19 18:53:43 +02:00 • committed by Greg Kroah-Hartman
commit 0361d50e86
1 changed files with 4 additions and 2 deletions
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6
arch/s390/include/asm/hugetlb.h
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@ -28,9 +28,11 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
static inline int prepare_hugepage_range(struct file *file,
unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
struct hstate *h = hstate_file(file);
if (len & ~huge_page_mask(h))
return -EINVAL;
if (addr & ~HPAGE_MASK)
if (addr & ~huge_page_mask(h))
return -EINVAL;
return 0;
}