This is a note to let you know that I've just added the patch titled
mm/migrate: fixup setting UFFD_WP flag
to the 5.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-migrate-fixup-setting-uffd_wp-flag.patch
and it can be found in the queue-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ebdf8321eeeb623aed60f7ed16f7445363230118 Mon Sep 17 00:00:00 2001
From: Alistair Popple <alistair@xxxxxxxxxxxx>
Date: Fri, 4 Sep 2020 16:35:58 -0700
Subject: mm/migrate: fixup setting UFFD_WP flag
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From: Alistair Popple <alistair@xxxxxxxxxxxx>
commit ebdf8321eeeb623aed60f7ed16f7445363230118 upstream.
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@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200825064232.10023-1-alistair@xxxxxxxxxxxx
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -251,7 +251,7 @@ static bool remove_migration_pte(struct
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);
}
}
Patches currently in stable-queue which might be from alistair@xxxxxxxxxxxx are
queue-5.8/mm-rmap-fixup-copying-of-soft-dirty-and-uffd-ptes.patch
queue-5.8/mm-migrate-fixup-setting-uffd_wp-flag.patch
