+ mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix2.patch added to mm-unstable branch

+ mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix2.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/khugepaged: collapse_pte_mapped_thp() with mmap_read_lock(): fix2
has been added to the -mm mm-unstable branch.  Its filename is
     mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix2.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix2.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: Hugh Dickins <hughd@google.com>
Subject: mm/khugepaged: collapse_pte_mapped_thp() with mmap_read_lock(): fix2
Date: Sat, 5 Aug 2023 20:59:27 -0700 (PDT)

Use ptep_clear() instead of pte_clear(): when CONFIG_PAGE_TABLE_CHECK=y,
ptep_clear() adds some accounting, missing which would cause a BUG later.

Link: https://lkml.kernel.org/r/e0197433-8a47-6a65-534d-eda26eeb78b0@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Qi Zheng <zhengqi.arch@bytedance.com>
Closes: https://lore.kernel.org/linux-mm/0df84f9f-e9b0-80b1-4c9e-95abc1a73a96@bytedance.com/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/khugepaged.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/khugepaged.c~mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix2
+++ a/mm/khugepaged.c
@@ -1655,7 +1655,7 @@ int collapse_pte_mapped_thp(struct mm_st
 		 * TLB flush can be left until pmdp_collapse_flush() does it.
 		 * PTE dirty? Shmem page is already dirty; file is read-only.
 		 */
-		pte_clear(mm, addr, pte);
+		ptep_clear(mm, addr, pte);
 		page_remove_rmap(page, vma, false);
 		nr_ptes++;
 	}
_

Patches currently in -mm which might be from hughd@google.com are

mm-userfaultfd-add-new-uffdio_poison-ioctl-fix.patch
mm-pgtable-add-rcu_read_lock-and-rcu_read_unlocks.patch
mm-pgtable-add-pae-safety-to-__pte_offset_map.patch
arm-adjust_pte-use-pte_offset_map_nolock.patch
powerpc-assert_pte_locked-use-pte_offset_map_nolock.patch
powerpc-assert_pte_locked-use-pte_offset_map_nolock-fix.patch
powerpc-add-pte_free_defer-for-pgtables-sharing-page.patch
sparc-add-pte_free_defer-for-pte_t-pgtable_t.patch
s390-add-pte_free_defer-for-pgtables-sharing-page.patch
s390-add-pte_free_defer-for-pgtables-sharing-page-fix.patch
mm-pgtable-add-pte_free_defer-for-pgtable-as-page.patch
mm-khugepaged-retract_page_tables-without-mmap-or-vma-lock.patch
mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock.patch
mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix.patch
mm-khugepaged-collapse_pte_mapped_thp-with-mmap_read_lock-fix2.patch
mm-khugepaged-delete-khugepaged_collapse_pte_mapped_thps.patch
mm-khugepaged-delete-khugepaged_collapse_pte_mapped_thps-fix.patch
mm-delete-mmap_write_trylock-and-vma_try_start_write.patch
mm-pgtable-notes-on-pte_offset_map.patch