The patch titled
Subject: mm: call arch_swap_restore() from unuse_pte()
has been added to the -mm mm-unstable branch. Its filename is
mm-call-arch_swap_restore-from-unuse_pte.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-call-arch_swap_restore-from-unuse_pte.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Peter Collingbourne <pcc@xxxxxxxxxx>
Subject: mm: call arch_swap_restore() from unuse_pte()
Date: Mon, 22 May 2023 17:43:09 -0700
We would like to move away from requiring architectures to restore
metadata from swap in the set_pte_at() implementation, as this is not only
error-prone but adds complexity to the arch-specific code. This requires
us to call arch_swap_restore() before calling swap_free() whenever pages
are restored from swap. We are currently doing so everywhere except in
unuse_pte(); do so there as well.
Link: https://lkml.kernel.org/r/20230523004312.1807357-3-pcc@xxxxxxxxxx
Link: https://linux-review.googlesource.com/id/I68276653e612d64cde271ce1b5a99ae05d6bbc4f
Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Alexandru Elisei <alexandru.elisei@xxxxxxx>
Cc: Chinwen Chang <chinwen.chang@xxxxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: kasan-dev <kasan-dev@xxxxxxxxxxxxxxxx>
Cc: "Kuan-Ying Lee (æ??å? ç©?)" <Kuan-Ying.Lee@xxxxxxxxxxxx>
Cc: Qun-Wei Lin <qun-wei.lin@xxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/mm/swapfile.c~mm-call-arch_swap_restore-from-unuse_pte
+++ a/mm/swapfile.c
@@ -1778,6 +1778,13 @@ static int unuse_pte(struct vm_area_stru
goto setpte;
}
+ /*
+ * Some architectures may have to restore extra metadata to the page
+ * when reading from swap. This metadata may be indexed by swap entry
+ * so this must be called before swap_free().
+ */
+ arch_swap_restore(entry, page_folio(page));
+
/* See do_swap_page() */
BUG_ON(!PageAnon(page) && PageMappedToDisk(page));
BUG_ON(PageAnon(page) && PageAnonExclusive(page));
_
Patches currently in -mm which might be from pcc@xxxxxxxxxx are
mm-call-arch_swap_restore-from-do_swap_page.patch
mm-call-arch_swap_restore-from-unuse_pte.patch
arm64-mte-simplify-swap-tag-restoration-logic.patch
