Re: [PATCH V3] mm/debug_vm_pgtable: Add [pte|pmd]_mkwrite_novma() tests
From: Huang, Ying
Date: Thu Oct 23 2025 - 22:00:35 EST
Anshuman Khandual <anshuman.khandual@xxxxxxx> writes:
> Add some [pte|pmd]_mkwrite_novma() relevant tests.
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Huang Ying <ying.huang@xxxxxxxxxxxxxxxxx>
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> These tests clear on arm64 platform after the following recent patch.
>
> https://lore.kernel.org/all/20251015023712.46598-1-ying.huang@xxxxxxxxxxxxxxxxx/
>
> Changes in V3:
>
> - Added a new test combination per Huang
>
> Changes in V2:
>
> https://lore.kernel.org/all/20251022032951.3498553-1-anshuman.khandual@xxxxxxx/
>
> - Added a new test combination per Huang
>
> Changes in V1:
>
> https://lore.kernel.org/all/20251021024424.2390325-1-anshuman.khandual@xxxxxxx/
>
> mm/debug_vm_pgtable.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 830107b6dd08..133543ca2821 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -102,6 +102,12 @@ static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
> WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte, args->vma))));
> WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte))));
> WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
> +
> + WARN_ON(!pte_dirty(pte_mkwrite_novma(pte_mkdirty(pte))));
> + WARN_ON(pte_dirty(pte_mkwrite_novma(pte_mkclean(pte))));
> + WARN_ON(!pte_write(pte_mkdirty(pte_mkwrite_novma(pte))));
> + WARN_ON(!pte_write(pte_mkwrite_novma(pte_wrprotect(pte))));
> + WARN_ON(pte_write(pte_wrprotect(pte_mkwrite_novma(pte))));
> }
>
> static void __init pte_advanced_tests(struct pgtable_debug_args *args)
> @@ -195,6 +201,13 @@ static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
> WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd, args->vma))));
> WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd))));
> WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd))));
> +
> + WARN_ON(!pmd_dirty(pmd_mkwrite_novma(pmd_mkdirty(pmd))));
> + WARN_ON(pmd_dirty(pmd_mkwrite_novma(pmd_mkclean(pmd))));
> + WARN_ON(!pmd_write(pmd_mkdirty(pmd_mkwrite_novma(pmd))));
> + WARN_ON(!pmd_write(pmd_mkwrite_novma(pmd_wrprotect(pmd))));
> + WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite_novma(pmd))));
> +
> /*
> * A huge page does not point to next level page table
> * entry. Hence this must qualify as pmd_bad().
LGTM, feel free to add my
Reviewed-by: Huang Ying <ying.huang@xxxxxxxxxxxxxxxxx>
in the future versions.
---
Best Regards,
Huang, Ying