From: Miaohe Lin linmiaohe@huawei.com
[ 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/20210325131524.48181-4-linmiaohe@huawei.com Fixes: df6ad69838fc ("mm/device-public-memory: device memory cache coherent with CPU") Signed-off-by: Miaohe Lin linmiaohe@huawei.com Reviewed-by: David Hildenbrand david@redhat.com Cc: Alistair Popple apopple@nvidia.com Cc: Jerome Glisse jglisse@redhat.com Cc: Rafael Aquini aquini@redhat.com Cc: Yang Shi shy828301@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/migrate.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/mm/migrate.c b/mm/migrate.c index 62b81d5257aa..773622cffe77 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2973,6 +2973,13 @@ 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);