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From: Guo Ren <guoren@kernel.org>
To: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Linux-MM <linux-mm@kvack.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Guo Ren <guoren@linux.alibaba.com>
Subject: Re: [PATCH V2] mm: debug_vm_pgtable: Don't use __P000 directly
Date: Mon, 27 Sep 2021 14:21:41 +0800	[thread overview]
Message-ID: <CAJF2gTRmvYBG5=NN4-53z2Gk-bC42LOHsEzHV6cnruoq1Xh0LA@mail.gmail.com> (raw)
In-Reply-To: <30c10b5f-1b26-e0a8-8185-6fa3296d68dc@arm.com>

Got it, thanks!

On Mon, Sep 27, 2021 at 10:16 AM Anshuman Khandual
<anshuman.khandual@arm.com> wrote:
>
>
>
> On 9/24/21 11:38 AM, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > 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@linux.alibaba.com>
> > Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
>
> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
>
>
> >
> > ---
> >
> > 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;
> >



-- 
Best Regards
 Guo Ren

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

      reply	other threads:[~2021-09-27  6:21 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24  6:08 [PATCH V2] mm: debug_vm_pgtable: Don't use __P000 directly guoren
2021-09-27  2:17 ` Anshuman Khandual
2021-09-27  6:21   ` Guo Ren [this message]

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