The patch titled
Subject: mm: teach mincore_hugetlb about pte markers
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-teach-mincore_hugetlb-about-pte-markers.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-teach-mincore_hugetlb-about-pte-markers.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: James Houghton <jthoughton@xxxxxxxxxx>
Subject: mm: teach mincore_hugetlb about pte markers
Date: Thu, 2 Mar 2023 22:24:04 +0000
By checking huge_pte_none(), we incorrectly classify PTE markers as
"present". Instead, check huge_pte_none_mostly(), classifying PTE markers
the same as if the PTE were completely blank.
PTE markers, unlike other kinds of swap entries, don't reference any
physical page and don't indicate that a physical page was mapped
previously. As such, treat them as non-present for the sake of mincore().
Link: https://lkml.kernel.org/r/20230302222404.175303-1-jthoughton@xxxxxxxxxx
Fixes: 5c041f5d1f23 ("mm: teach core mm about pte markers")
Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx>
Acked-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: James Houghton <jthoughton@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/mincore.c~mm-teach-mincore_hugetlb-about-pte-markers
+++ a/mm/mincore.c
@@ -33,7 +33,7 @@ static int mincore_hugetlb(pte_t *pte, u
* Hugepages under user process are always in RAM and never
* swapped out, but theoretically it needs to be checked.
*/
- present = pte && !huge_pte_none(huge_ptep_get(pte));
+ present = pte && !huge_pte_none_mostly(huge_ptep_get(pte));
for (; addr != end; vec++, addr += PAGE_SIZE)
*vec = present;
walk->private = vec;
_
Patches currently in -mm which might be from jthoughton@xxxxxxxxxx are
mm-teach-mincore_hugetlb-about-pte-markers.patch
