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From:   Daniel Axtens <dja@axtens.net>
To:     Michal Suchanek <msuchanek@suse.de>, keyrings@vger.kernel.org
Cc:     Rob Herring <robh@kernel.org>, linux-s390@vger.kernel.org,
        Vasily Gorbik <gor@linux.ibm.com>,
        Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Jessica Yu <jeyu@kernel.org>, linux-kernel@vger.kernel.org,
        David Howells <dhowells@redhat.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Paul Mackerras <paulus@samba.org>,
        Hari Bathini <hbathini@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Michal Suchanek <msuchanek@suse.de>,
        linuxppc-dev@lists.ozlabs.org,
        Frank van der Linden <fllinden@amazon.com>,
        Thiago Jung Bauermann <bauerman@linux.ibm.com>
Subject: Re: [PATCH 0/3] KEXEC_SIG with appended signature
In-Reply-To: <cover.1635948742.git.msuchanek@suse.de>
References: <cover.1635948742.git.msuchanek@suse.de>
Date:   Fri, 05 Nov 2021 21:55:52 +1100
Message-ID: <87czneeurr.fsf@dja-thinkpad.axtens.net>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Michal Suchanek <msuchanek@suse.de> writes:

> S390 uses appended signature for kernel but implements the check
> separately from module loader.
>
> Support for secure boot on powerpc with appended signature is planned -
> grub patches submitted upstream but not yet merged.

Power Non-Virtualised / OpenPower already supports secure boot via kexec
with signature verification via IMA. I think you have now sent a
follow-up series that merges some of the IMA implementation, I just
wanted to make sure it was clear that we actually already have support
for this in the kernel, it's just grub that is getting new support.

> This is an attempt at unified appended signature verification.

I am always in favour of fewer reimplementations of the same feature in
the kernel :)

Regards,
Daniel

>
> Thanks
>
> Michal
>
> Michal Suchanek (3):
>   s390/kexec_file: Don't opencode appended signature verification.
>   module: strip the signature marker in the verification function.
>   powerpc/kexec_file: Add KEXEC_SIG support.
>
>  arch/powerpc/Kconfig                  | 11 +++++++
>  arch/powerpc/kexec/elf_64.c           | 14 +++++++++
>  arch/s390/kernel/machine_kexec_file.c | 42 +++------------------------
>  include/linux/verification.h          |  3 ++
>  kernel/module-internal.h              |  2 --
>  kernel/module.c                       | 11 +++----
>  kernel/module_signing.c               | 32 ++++++++++++++------
>  7 files changed, 59 insertions(+), 56 deletions(-)
>
> -- 
> 2.31.1