[v3,11/13] mm/debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries

Commit Message

Aneesh Kumar K.V Aug. 27, 2020, 8:04 a.m. UTC

pmd_clear() should not be used to clear pmd level pte entries.

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

Patch

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 0a6e771ebd13..a188b6e4e37e 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -196,6 +196,8 @@  static void __init pmd_advanced_tests(struct mm_struct *mm,
 	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);
 }
 
@@ -321,6 +323,8 @@  static void __init pud_advanced_tests(struct mm_struct *mm,
 	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)
@@ -444,8 +448,6 @@  static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
 	 * 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));
@@ -577,7 +579,6 @@  static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
 	 * 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));