Subject: [PATCH v4 13/13] mm/debug_vm_pgtable: Avoid none pte in pte_clear_test

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Wed, 2 Sep 2020 17:12:22 +0530

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

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 mm/debug_vm_pgtable.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 9afa1354326b..c36530c69e33 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -542,9 +542,10 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
 #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);
 
-- 
2.26.2