mm/migrate.c: fix potential indeterminate pte entry in migrate_vma_insert_page()

[ Upstream commit 34f5e9b9d1990d286199084efa752530ee3d8297 ]

If the zone device page does not belong to un-addressable device memory,
the variable entry will be uninitialized and lead to indeterminate pte
entry ultimately.  Fix this unexpected case and warn about it.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: df6ad69838 ("mm/device-public-memory: device memory cache coherent with CPU")
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Rafael Aquini <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
This commit is contained in:
Miaohe Lin 2021-05-04 18:37:10 -07:00 • committed by Greg Kroah-Hartman
commit dde73137ce

View file

@ -2771,6 +2771,13 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
swp_entry = make_device_private_entry(page, vma->vm_flags & VM_WRITE);
entry = swp_entry_to_pte(swp_entry);
} else {
/*
* For now we only support migrating to un-addressable
* device memory.
*/
pr_warn_once("Unsupported ZONE_DEVICE page type.\n");
goto abort;
}
} else {
entry = mk_pte(page, vma->vm_page_prot);