On 09/02/2020 05:12 PM, Aneesh Kumar K.V wrote:
> Make sure we call pte accessors with correct lock held.
>
> Signed-off-by: Aneesh Kumar K.V
> ---
> mm/debug_vm_pgtable.c | 35 ++-
> 1 file changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index f59cf6a9b05e..2bc1952e5f83 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/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(>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(>page_table_lock);
>
> p4d_free(mm, saved_p4dp);
> pud_free(mm, saved_pudp);
>
This patch, in itself looks good but will probably require folding with
the previous one to prevent the git bisect problem on arm64.
