set_pte_at() should not be used to set a pte entry at locations that already holds a valid pte entry. Architectures like ppc64 don't do TLB invalidate in set_pte_at() and hence expect it to be used to set locations that are not a valid PTE. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> --- mm/debug_vm_pgtable.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 4c32063a8acf..02a7c20aa4a2 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -81,8 +81,6 @@ static void __init pte_advanced_tests(struct mm_struct *mm, pte = ptep_get(ptep); WARN_ON(pte_write(pte)); - pte = pfn_pte(pfn, prot); - set_pte_at(mm, vaddr, ptep, pte); ptep_get_and_clear(mm, vaddr, ptep); pte = ptep_get(ptep); WARN_ON(!pte_none(pte)); @@ -97,12 +95,14 @@ static void __init pte_advanced_tests(struct mm_struct *mm, pte = ptep_get(ptep); WARN_ON(!(pte_write(pte) && pte_dirty(pte))); - pte = pfn_pte(pfn, prot); - set_pte_at(mm, vaddr, ptep, pte); ptep_get_and_clear_full(mm, vaddr, ptep, 1); pte = ptep_get(ptep); WARN_ON(!pte_none(pte)); + /* + * We should clear pte before we do set_pte_at + */ + pte = ptep_get_and_clear(mm, vaddr, ptep); pte = pte_mkyoung(pte); set_pte_at(mm, vaddr, ptep, pte); ptep_test_and_clear_young(vma, vaddr, ptep); -- 2.26.2
