Subject: [PATCH v2 10/13] mm/debug_vm_pgtable/locks: Take correct page table lock

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Wed, 19 Aug 2020 18:31:04 +0530

Make sure we call pte accessors with correct lock held.

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 mm/debug_vm_pgtable.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 69fe3cd8126c..8f7a8ccb5a54 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -1024,33 +1024,39 @@ static int __init debug_vm_pgtable(void)
 	pmd_thp_tests(pmd_aligned, prot);
 	pud_thp_tests(pud_aligned, prot);
 
+	hugetlb_basic_tests(pte_aligned, prot);
+
 	/*
 	 * Page table modifying tests
 	 */
-	pte_clear_tests(mm, ptep, vaddr);
-	pmd_clear_tests(mm, pmdp);
-	pud_clear_tests(mm, pudp);
-	p4d_clear_tests(mm, p4dp);
-	pgd_clear_tests(mm, pgdp);
 
 	ptep = pte_alloc_map_lock(mm, pmdp, vaddr, &ptl);
+	pte_clear_tests(mm, ptep, vaddr);
 	pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
-	pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
-	pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
-	hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
-
+	pte_unmap_unlock(ptep, ptl);
 
+	ptl = pmd_lock(mm, pmdp);
+	pmd_clear_tests(mm, pmdp);
+	pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
 	pmd_huge_tests(pmdp, pmd_aligned, prot);
+	pmd_populate_tests(mm, pmdp, saved_ptep);
+	spin_unlock(ptl);
+
+	ptl = pud_lock(mm, pudp);
+	pud_clear_tests(mm, pudp);
+	pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
 	pud_huge_tests(pudp, pud_aligned, prot);
+	pud_populate_tests(mm, pudp, saved_pmdp);
+	spin_unlock(ptl);
 
-	pte_unmap_unlock(ptep, ptl);
+	//hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
 
-	pmd_populate_tests(mm, pmdp, saved_ptep);
-	pud_populate_tests(mm, pudp, saved_pmdp);
+	spin_lock(&mm->page_table_lock);
+	p4d_clear_tests(mm, p4dp);
+	pgd_clear_tests(mm, pgdp);
 	p4d_populate_tests(mm, p4dp, saved_pudp);
 	pgd_populate_tests(mm, pgdp, saved_p4dp);
-
-	hugetlb_basic_tests(pte_aligned, prot);
+	spin_unlock(&mm->page_table_lock);
 
 	p4d_free(mm, saved_p4dp);
 	pud_free(mm, saved_pudp);
-- 
2.26.2