[merged mm-stable] s390-mm-add-missing-ctor-dtor-on-page-table-upgrade.patch removed from -mm tree

[merged mm-stable] s390-mm-add-missing-ctor-dtor-on-page-table-upgrade.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: s390/mm: add missing ctor/dtor on page table upgrade
has been removed from the -mm tree.  Its filename was
     s390-mm-add-missing-ctor-dtor-on-page-table-upgrade.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: Alexander Gordeev <agordeev@linux.ibm.com>
Subject: s390/mm: add missing ctor/dtor on page table upgrade
Date: Thu, 23 Jan 2025 17:03:49 +0100

Commit 78966b550289 ("s390: pgtable: add statistics for PUD and P4D level
page table") misses the call to pagetable_p4d_ctor() against a newly
allocated P4D table in crst_table_upgrade();

Commit 68c601de75d8 ("mm: introduce ctor/dtor at PGD level") misses the
call to pagetable_pgd_ctor() against a newly allocated PGD and the call to
pagetable_dtor() against a newly allocated P4D that is about to be freed
on crst_table_upgrade() PGD upgrade fail path.

The missed constructors and destructor break (at least) the page table
accounting when a process memory space is upgraded.

Link: https://lkml.kernel.org/r/20250123160349.200154-1-agordeev@linux.ibm.com
Fixes: 78966b550289 ("s390: pgtable: add statistics for PUD and P4D level page table")
Fixes: 68c601de75d8 ("mm: introduce ctor/dtor at PGD level")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Closes: https://lore.kernel.org/all/20250122074954.8685-A-hca@linux.ibm.com/
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/s390/mm/pgalloc.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/s390/mm/pgalloc.c~s390-mm-add-missing-ctor-dtor-on-page-table-upgrade
+++ a/arch/s390/mm/pgalloc.c
@@ -88,12 +88,14 @@ int crst_table_upgrade(struct mm_struct
 		if (unlikely(!p4d))
 			goto err_p4d;
 		crst_table_init(p4d, _REGION2_ENTRY_EMPTY);
+		pagetable_p4d_ctor(virt_to_ptdesc(p4d));
 	}
 	if (end > _REGION1_SIZE) {
 		pgd = crst_table_alloc(mm);
 		if (unlikely(!pgd))
 			goto err_pgd;
 		crst_table_init(pgd, _REGION1_ENTRY_EMPTY);
+		pagetable_pgd_ctor(virt_to_ptdesc(pgd));
 	}
 
 	spin_lock_bh(&mm->page_table_lock);
@@ -130,6 +132,7 @@ int crst_table_upgrade(struct mm_struct
 	return 0;
 
 err_pgd:
+	pagetable_dtor(virt_to_ptdesc(p4d));
 	crst_table_free(mm, p4d);
 err_p4d:
 	return -ENOMEM;
_

Patches currently in -mm which might be from agordeev@linux.ibm.com are