[merged mm-stable] mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64.patch removed from -mm tree

[merged mm-stable] mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/migrate: revert "mm/migrate: fix wrongly apply write bit after mkdirty on sparc64"
has been removed from the -mm tree.  Its filename was
     mm-migrate-revert-mm-migrate-fix-wrongly-apply-write-bit-after-mkdirty-on-sparc64.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
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@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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
@@ -3276,6 +3276,8 @@ 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))
@@ -3283,10 +3285,6 @@ 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@redhat.com are

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
mm-dont-check-vma-write-permissions-if-the-pte-pmd-indicates-write-permissions.patch