The patch titled
Subject: s390/mm: add missing ctor/dtor on page table upgrade
has been added to the -mm mm-unstable branch. Its filename is
s390-mm-add-missing-ctor-dtor-on-page-table-upgrade.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/s390-mm-add-missing-ctor-dtor-on-page-table-upgrade.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: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx
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@xxxxxxxxxxxxx>
Reported-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Closes: https://lore.kernel.org/all/20250122074954.8685-A-hca@xxxxxxxxxxxxx/
Suggested-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Reviewed-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Acked-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxx are
s390-mm-add-missing-ctor-dtor-on-page-table-upgrade.patch
