+ mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch added to -mm tree

+ mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/debug_vm_pgtable: avoid none pte in pte_clear_test
has been added to the -mm tree.  Its filename is
     mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch

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------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: mm/debug_vm_pgtable: avoid none pte in pte_clear_test

pte_clear_tests operate on an existing pte entry.  Make sure that is not a
none pte entry.

Link: https://lkml.kernel.org/r/20200902114222.181353-14-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/debug_vm_pgtable.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test
+++ a/mm/debug_vm_pgtable.c
@@ -542,9 +542,10 @@ static void __init pgd_populate_tests(st
 #endif /* PAGETABLE_P4D_FOLDED */
 
 static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
-				   unsigned long vaddr)
+				   unsigned long pfn, unsigned long vaddr,
+				   pgprot_t prot)
 {
-	pte_t pte = ptep_get(ptep);
+	pte_t pte = pfn_pte(pfn, prot);
 
 	pr_debug("Validating PTE clear\n");
 	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
@@ -1049,7 +1050,7 @@ static int __init debug_vm_pgtable(void)
 
 	ptl = pte_lockptr(mm, pmdp);
 	spin_lock(ptl);
-	pte_clear_tests(mm, ptep, vaddr);
+	pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot);
 	pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
 	pte_unmap_unlock(ptep, ptl);
 
_

Patches currently in -mm which might be from aneesh.kumar@linux.ibm.com 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