The patch titled Subject: mm/hmm: Fix bad subpage pointer in try_to_unmap_one has been added to the -mm tree. Its filename is mm-hmm-fix-bad-subpage-pointer-in-try_to_unmap_one.patch

This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-hmm-fix-bad-subpage-pointer-in-t... and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-hmm-fix-bad-subpage-pointer-in-t...

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------------------------------------------------------ From: Ralph Campbell rcampbell@nvidia.com Subject: mm/hmm: Fix bad subpage pointer in try_to_unmap_one

When migrating a ZONE device private page from device memory to system memory, the subpage pointer is initialized from a swap pte which computes an invalid page pointer. A kernel panic results such as:

BUG: unable to handle page fault for address: ffffea1fffffffc8

Initialize subpage correctly before calling page_remove_rmap().

Link: http://lkml.kernel.org/r/20190709223556.28908-1-rcampbell@nvidia.com Fixes: a5430dda8a3a1c ("mm/migrate: support un-addressable ZONE_DEVICE page in migration") Signed-off-by: Ralph Campbell rcampbell@nvidia.com Cc: "Jérôme Glisse" jglisse@redhat.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Jason Gunthorpe jgg@mellanox.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/rmap.c | 1 + 1 file changed, 1 insertion(+)

--- a/mm/rmap.c~mm-hmm-fix-bad-subpage-pointer-in-try_to_unmap_one +++ a/mm/rmap.c @@ -1476,6 +1476,7 @@ static bool try_to_unmap_one(struct page * No need to invalidate here it will synchronize on * against the special swap migration pte. */ + subpage = page; goto discard; }

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Patches currently in -mm which might be from rcampbell@nvidia.com are

mm-hmm-fix-bad-subpage-pointer-in-try_to_unmap_one.patch