The patch titled
Subject: mm/migrate: revert "mm/migrate: fix wrongly apply write bit after mkdirty on sparc64"
has been added to the -mm mm-unstable branch. Its filename is
mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/migrate: revert "mm/migrate: fix wrongly apply write bit after mkdirty on sparc64"
Date: Tue, 11 Apr 2023 16:25:10 +0200
This reverts commit 96a9c287e25d ("mm/migrate: fix wrongly apply write bit
after mkdirty on sparc64").
Now that sparc64 mkdirty handling is fixed and no longer sets a PTE/PMD
writable that shouldn't be writable, let's revert the temporary fix.
The mkdirty mm selftest still passes with this change on sparc64.
Note that loongarch handling was fixed in commit bf2f34a506e6 ("LoongArch:
Set _PAGE_DIRTY only if _PAGE_WRITE is set in {pmd,pte}_mkdirty()").
Link: https://lkml.kernel.org/r/20230411142512.438404-5-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 6 ++----
mm/migrate.c | 2 --
2 files changed, 2 insertions(+), 6 deletions(-)
--- a/mm/huge_memory.c~mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64
+++ a/mm/huge_memory.c
@@ -3335,6 +3335,8 @@ void remove_migration_pmd(struct page_vm
pmde = mk_huge_pmd(new, READ_ONCE(vma->vm_page_prot));
if (pmd_swp_soft_dirty(*pvmw->pmd))
pmde = pmd_mksoft_dirty(pmde);
+ if (is_writable_migration_entry(entry))
+ pmde = maybe_pmd_mkwrite(pmde, vma);
if (pmd_swp_uffd_wp(*pvmw->pmd))
pmde = pmd_mkuffd_wp(pmde);
if (!is_migration_entry_young(entry))
@@ -3342,10 +3344,6 @@ void remove_migration_pmd(struct page_vm
/* NOTE: this may contain setting soft-dirty on some archs */
if (PageDirty(new) && is_migration_entry_dirty(entry))
pmde = pmd_mkdirty(pmde);
- if (is_writable_migration_entry(entry))
- pmde = maybe_pmd_mkwrite(pmde, vma);
- else
- pmde = pmd_wrprotect(pmde);
if (PageAnon(new)) {
rmap_t rmap_flags = RMAP_COMPOUND;
--- a/mm/migrate.c~mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64
+++ a/mm/migrate.c
@@ -225,8 +225,6 @@ static bool remove_migration_pte(struct
pte = maybe_mkwrite(pte, vma);
else if (pte_swp_uffd_wp(*pvmw.pte))
pte = pte_mkuffd_wp(pte);
- else
- pte = pte_wrprotect(pte);
if (folio_test_anon(folio) && !is_readable_migration_entry(entry))
rmap_flags |= RMAP_EXCLUSIVE;
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-userfaultfd-fix-uffd-wp-handling-for-thp-migration-entries.patch
m68k-mm-use-correct-bit-number-in-_page_swp_exclusive-comment.patch
mm-userfaultfd-dont-consider-uffd-wp-bit-of-writable-migration-entries.patch
selftests-mm-reuse-read_pmd_pagesize-in-cow-selftest.patch
selftests-mm-mkdirty-test-behavior-of-ptepmd_mkdirty-on-vmas-without-write-permissions.patch
sparc-mm-dont-unconditionally-set-hw-writable-bit-when-setting-pte-dirty-on-64bit.patch
mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64.patch
mm-huge_memory-revert-partly-revert-mm-thp-carry-over-dirty-bit-when-thp-splits-on-pmd.patch
mm-huge_memory-conditionally-call-maybe_mkwrite-and-drop-pte_wrprotect-in-__split_huge_pmd_locked.patch
