mm/debug_vm_pgtable/locks: take correct page table lock

Make sure we call pte accessors with correct lock held.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lkml.kernel.org/r/20200902114222.181353-10-aneesh.kumar@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 3ed3fb6..d9f00ee 100644 (file)
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -1033,30 +1033,39 @@ static int __init debug_vm_pgtable(void)
 
        hugetlb_basic_tests(pte_aligned, prot);
 
-       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);
+       /*
+        * Page table modifying tests. They need to hold
+        * proper page table lock.
+        */
 
        ptl = pte_lockptr(mm, pmdp);
        spin_lock(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);
-       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);
        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);
+       spin_unlock(&mm->page_table_lock);
 
        p4d_free(mm, saved_p4dp);
        pud_free(mm, saved_pudp);