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[1/2] mm/migrate: Fixup setting UFFD_WP flag

Message ID 20200824083128.12684-1-alistair@popple.id.au
State New
Headers show
Series [1/2] mm/migrate: Fixup setting UFFD_WP flag | expand

Commit Message

Alistair Popple Aug. 24, 2020, 8:31 a.m. UTC
Commit f45ec5ff16a75 ("userfaultfd: wp: support swap and page
migration") introduced support for tracking the uffd wp bit during page
migration. However the non-swap PTE variant was used to set the flag for
zone device private pages which are a type of swap page.

This leads to corruption of the swap offset if the original PTE has the
uffd_wp flag set.

Fixes: f45ec5ff16a75 ("userfaultfd: wp: support swap and page migration")
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Cc: stable@vger.kernel.org
---
 mm/migrate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

diff --git a/mm/migrate.c b/mm/migrate.c
index 34a842a8eb6a..ddb64253fe3e 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -251,7 +251,7 @@  static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 				entry = make_device_private_entry(new, pte_write(pte));
 				pte = swp_entry_to_pte(entry);
 				if (pte_swp_uffd_wp(*pvmw.pte))
-					pte = pte_mkuffd_wp(pte);
+					pte = pte_swp_mkuffd_wp(pte);
 			}
 		}