From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Subject: mm/debug_vm_pgtable/locks: take correct page table lock Make sure we call pte accessors with correct lock held. Link: https://lkml.kernel.org/r/20200902114222.181353-10-aneesh.kumar@xxxxxxxxxxxxx Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/debug_vm_pgtable.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) --- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-locks-take-correct-page-table-lock +++ a/mm/debug_vm_pgtable.c @@ -1035,30 +1035,39 @@ 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); _
