The patch titled
Subject: mm/debug_vm_pgtable/pmd_clear: don't use pmd/pud_clear on pte entries
has been added to the -mm tree. Its filename is
mm-debug_vm_pgtable-pmd_clear-dont-use-pmd-pud_clear-on-pte-entries.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-debug_vm_pgtable-pmd_clear-dont-use-pmd-pud_clear-on-pte-entries.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-debug_vm_pgtable-pmd_clear-dont-use-pmd-pud_clear-on-pte-entries.patch
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------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Subject: mm/debug_vm_pgtable/pmd_clear: don't use pmd/pud_clear on pte entries
pmd_clear() should not be used to clear pmd level pte entries.
Link: https://lkml.kernel.org/r/20200902114222.181353-12-aneesh.kumar@xxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/debug_vm_pgtable.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-pmd_clear-dont-use-pmd-pud_clear-on-pte-entries
+++ a/mm/debug_vm_pgtable.c
@@ -196,6 +196,8 @@ static void __init pmd_advanced_tests(st
pmd = READ_ONCE(*pmdp);
WARN_ON(pmd_young(pmd));
+ /* Clear the pte entries */
+ pmdp_huge_get_and_clear(mm, vaddr, pmdp);
pgtable = pgtable_trans_huge_withdraw(mm, pmdp);
}
@@ -319,6 +321,8 @@ static void __init pud_advanced_tests(st
pudp_test_and_clear_young(vma, vaddr, pudp);
pud = READ_ONCE(*pudp);
WARN_ON(pud_young(pud));
+
+ pudp_huge_get_and_clear(mm, vaddr, pudp);
}
static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
@@ -442,8 +446,6 @@ static void __init pud_populate_tests(st
* This entry points to next level page table page.
* Hence this must not qualify as pud_bad().
*/
- pmd_clear(pmdp);
- pud_clear(pudp);
pud_populate(mm, pudp, pmdp);
pud = READ_ONCE(*pudp);
WARN_ON(pud_bad(pud));
@@ -575,7 +577,6 @@ static void __init pmd_populate_tests(st
* This entry points to next level page table page.
* Hence this must not qualify as pmd_bad().
*/
- pmd_clear(pmdp);
pmd_populate(mm, pmdp, pgtable);
pmd = READ_ONCE(*pmdp);
WARN_ON(pmd_bad(pmd));
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxx are
powerpc-mm-add-debug_vm-warn-for-pmd_clear.patch
powerpc-mm-move-setting-pte-specific-flags-to-pfn_pte.patch
mm-debug_vm_pgtable-ppc64-avoid-setting-top-bits-in-radom-value.patch
mm-debug_vm_pgtables-hugevmap-use-the-arch-helper-to-identify-huge-vmap-support.patch
mm-debug_vm_pgtable-savedwrite-enable-savedwrite-test-with-config_numa_balancing.patch
mm-debug_vm_pgtable-thp-mark-the-pte-entry-huge-before-using-set_pmd-pud_at.patch
mm-debug_vm_pgtable-set_pte-pmd-pud-dont-use-set__at-to-update-an-existing-pte-entry.patch
mm-debug_vm_pgtable-locks-move-non-page-table-modifying-test-together.patch
mm-debug_vm_pgtable-locks-take-correct-page-table-lock.patch
mm-debug_vm_pgtable-thp-use-page-table-depost-withdraw-with-thp.patch
mm-debug_vm_pgtable-pmd_clear-dont-use-pmd-pud_clear-on-pte-entries.patch
mm-debug_vm_pgtable-hugetlb-disable-hugetlb-test-on-ppc64.patch
mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch
