linux-kernel - Re: [PATCH v4 27/34] KVM: arm64: Always zero invalid PTEs

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20210311173338.GB31378@willie-the-truck>
Date:   Thu, 11 Mar 2021 17:33:38 +0000
From:   Will Deacon <will@...nel.org>
To:     Quentin Perret <qperret@...gle.com>
Cc:     catalin.marinas@....com, maz@...nel.org, james.morse@....com,
        julien.thierry.kdev@...il.com, suzuki.poulose@....com,
        android-kvm@...gle.com, linux-kernel@...r.kernel.org,
        kernel-team@...roid.com, kvmarm@...ts.cs.columbia.edu,
        linux-arm-kernel@...ts.infradead.org, tabba@...gle.com,
        mark.rutland@....com, dbrazdil@...gle.com, mate.toth-pal@....com,
        seanjc@...gle.com, robh+dt@...nel.org, ardb@...nel.org
Subject: Re: [PATCH v4 27/34] KVM: arm64: Always zero invalid PTEs

On Wed, Mar 10, 2021 at 05:57:44PM +0000, Quentin Perret wrote:
> kvm_set_invalid_pte() currently only clears bit 0 from a PTE because
> stage2_map_walk_table_post() needs to be able to follow the anchor. In
> preparation for re-using bits 63-02 from invalid PTEs, make sure to zero

Why do you exclude bit 1 from this range?

> it entirely by ensuring to cache the anchor's child upfront.
> 
> Suggested-by: Will Deacon <will@...nel.org>
> Signed-off-by: Quentin Perret <qperret@...gle.com>
> ---
>  arch/arm64/kvm/hyp/pgtable.c | 26 ++++++++++++++++----------
>  1 file changed, 16 insertions(+), 10 deletions(-)

For the patch:

Acked-by: Will Deacon <will@...nel.org>

Will