linux-kernel - Re: [PATCH] arm64/mm: Define PTE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAMj1kXE0mCPSKLyNUkLZXLntX-=aCGKdn5b3Zgme3PbyYFgFdg@mail.gmail.com>
Date: Fri, 7 Mar 2025 12:16:34 +0100
From: Ard Biesheuvel <ardb@...nel.org>
To: Anshuman Khandual <anshuman.khandual@....com>
Cc: Ryan Roberts <ryan.roberts@....com>, linux-arm-kernel@...ts.infradead.org, 
	Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>, 
	Mark Rutland <mark.rutland@....com>, Andrey Ryabinin <ryabinin.a.a@...il.com>, 
	Alexander Potapenko <glider@...gle.com>, Andrey Konovalov <andreyknvl@...il.com>, 
	Dmitry Vyukov <dvyukov@...gle.com>, linux-kernel@...r.kernel.org, 
	kasan-dev@...glegroups.com
Subject: Re: [PATCH] arm64/mm: Define PTE_SHIFT

On Fri, 7 Mar 2025 at 10:21, Anshuman Khandual
<anshuman.khandual@....com> wrote:
>
>
>
> On 3/7/25 14:37, Ryan Roberts wrote:
> > On 07/03/2025 05:08, Anshuman Khandual wrote:
> >> Address bytes shifted with a single 64 bit page table entry (any page table
> >> level) has been always hard coded as 3 (aka 2^3 = 8). Although intuitive it
> >> is not very readable or easy to reason about. Besides it is going to change
> >> with D128, where each 128 bit page table entry will shift address bytes by
> >> 4 (aka 2^4 = 16) instead.
> >>
> >> Let's just formalise this address bytes shift value into a new macro called
> >> PTE_SHIFT establishing a logical abstraction, thus improving readability as
> >> well. This does not cause any functional change.
> >>
> >> Cc: Catalin Marinas <catalin.marinas@....com>
> >> Cc: Will Deacon <will@...nel.org>
> >> Cc: Mark Rutland <mark.rutland@....com>
> >> Cc: Andrey Ryabinin <ryabinin.a.a@...il.com>
> >> Cc: Alexander Potapenko <glider@...gle.com>
> >> Cc: Andrey Konovalov <andreyknvl@...il.com>
> >> Cc: Dmitry Vyukov <dvyukov@...gle.com>
> >> Cc: Ard Biesheuvel <ardb@...nel.org>
> >> Cc: Ryan Roberts <ryan.roberts@....com>
> >> Cc: linux-arm-kernel@...ts.infradead.org
> >> Cc: linux-kernel@...r.kernel.org
> >> Cc: kasan-dev@...glegroups.com
> >> Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
> >
> >
> > +1 for PTDESC_ORDER
>
> Alright.
>

Agreed.

> >
> > Implementation looks good to me so:
> >
> > Reviewed-by: Ryan Roberts <ryan.roberts@....com>
>

With PTDESC_ORDER used throughout,

Acked-by: Ard Biesheuvel <ardb@...nel.org>