linux-kernel - Re: [PATCH v4 03/17] arm64: kvm: stop treating register x18 as caller save

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: <63921b46250e2eb8eb9fcf0f8ec93b0c@www.loen.fr>
Date:   Mon, 04 Nov 2019 14:39:34 +0109
From:   Marc Zyngier <maz@...nel.org>
To:     Sami Tolvanen <samitolvanen@...gle.com>
Cc:     Will Deacon <will@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Dave Martin <dave.martin@....com>,
        Kees Cook <keescook@...omium.org>,
        Laura Abbott <labbott@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Jann Horn <jannh@...gle.com>,
        Miguel Ojeda <miguel.ojeda.sandonis@...il.com>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        <clang-built-linux@...glegroups.com>,
        <kernel-hardening@...ts.openwall.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 03/17] arm64: kvm: stop treating register x18 as  caller save

On 2019-11-04 12:13, Marc Zyngier wrote:
> Hi Sami,
>
> On 2019-11-01 23:20, Sami Tolvanen wrote:
>> From: Ard Biesheuvel <ard.biesheuvel@...aro.org>
>>
>> In preparation of reserving x18, stop treating it as caller save in
>> the KVM guest entry/exit code. Currently, the code assumes there is
>> no need to preserve it for the host, given that it would have been
>> assumed clobbered anyway by the function call to __guest_enter().
>> Instead, preserve its value and restore it upon return.
>>
>> Link: https://patchwork.kernel.org/patch/9836891/
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
>> [Sami: updated commit message, switched from x18 to x29 for the 
>> guest
>> context]
>> Signed-off-by: Sami Tolvanen <samitolvanen@...gle.com>
>> Reviewed-by: Kees Cook <keescook@...omium.org>
>
> If you intend for this to be merged via the arm64 tree, please add my
>
> Reviewed-by: Marc Zyngier <marc.zyngier@....com>

Erm... Muscle memory strikes again. Please ignore the above and use the
following instead:

Reviewed-by: Marc Zyngier <maz@...nel.org>

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...