Re: [PATCH] mm: debug_vm_pgtable: Don't use __P000 directly

[Guo Ren]

Sorry, the patch forgets to add --prefix PATCH V2, abandon.

Review the V2, thx.

On Fri, Sep 24, 2021 at 2:07 PM <guoren@xxxxxxxxxx> wrote:
>
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> The __Pxxx/__Sxxx macros are only for protection_map[] init. All
> usage of them in linux should come from protection_map array.
>
> Because a lot of architectures would re-initilize protection_map[]
> array, eg: x86-mem_encrypt, m68k-motorola, mips, arm, sparc.
>
> Using __P000 is not rigorous.
>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>
> ---
>
> Changes since V2:
>  - s/init protection_map[]/protection_map[] init/
>  - s/Becasue/Because/
>  - Remove unclear part
>  - Replace __P000 and __S000 with protection_map[0] and
>    protection_map[8]
> ---
>  mm/debug_vm_pgtable.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 1403639302e4..228e3954b90c 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -1104,13 +1104,14 @@ static int __init init_args(struct pgtable_debug_args *args)
>         /*
>          * Initialize the debugging data.
>          *
> -        * __P000 (or even __S000) will help create page table entries with
> -        * PROT_NONE permission as required for pxx_protnone_tests().
> +        * protection_map[0] (or even protection_map[8]) will help create
> +        * page table entries with PROT_NONE permission as required for
> +        * pxx_protnone_tests().
>          */
>         memset(args, 0, sizeof(*args));
>         args->vaddr              = get_random_vaddr();
>         args->page_prot          = vm_get_page_prot(VMFLAGS);
> -       args->page_prot_none     = __P000;
> +       args->page_prot_none     = protection_map[0];
>         args->is_contiguous_page = false;
>         args->pud_pfn            = ULONG_MAX;
>         args->pmd_pfn            = ULONG_MAX;
> --
> 2.25.1
>


-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/