Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v4 1/5] powerpc: Refactor kexec functions to move arch
 independent code to IMA
To:     Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc:     zohar@linux.ibm.com, robh@kernel.org, gregkh@linuxfoundation.org,
        james.morse@arm.com, catalin.marinas@arm.com, sashal@kernel.org,
        will@kernel.org, mpe@ellerman.id.au, benh@kernel.crashing.org,
        paulus@samba.org, robh+dt@kernel.org, frowand.list@gmail.com,
        vincenzo.frascino@arm.com, mark.rutland@arm.com,
        dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com,
        pasha.tatashin@soleen.com, allison@lohutok.net,
        kstewart@linuxfoundation.org, takahiro.akashi@linaro.org,
        tglx@linutronix.de, masahiroy@kernel.org, bhsharma@redhat.com,
        mbrugger@suse.com, hsinyi@chromium.org, tao.li@vivo.com,
        christophe.leroy@c-s.fr, linux-integrity@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        prsriva@linux.microsoft.com, balajib@linux.microsoft.com
References: <20200819172134.11243-1-nramas@linux.microsoft.com>
 <20200819172134.11243-2-nramas@linux.microsoft.com>
 <875z938xwy.fsf@morokweng.localdomain>
From:   Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Message-ID: <3897c55e-11d2-113a-5cef-db750b33772f@linux.microsoft.com>
Date:   Fri, 28 Aug 2020 10:40:58 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <875z938xwy.fsf@morokweng.localdomain>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 8/27/20 4:35 PM, Thiago Jung Bauermann wrote:
> 
> Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:
> 
>> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer() that
>> handle carrying forward the IMA measurement logs on kexec for powerpc
>> do not have architecture specific code, but they are currently defined
>> for powerpc only.
>>
>> Move these functions to IMA subsystem so that it can be used for other
>> architectures as well. A later patch in this series will use these
>> functions for carrying forward the IMA measurement log for ARM64.
>>
>> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
>> "linux,ima-kexec-buffer", that is added to the DTB to hold
>> the address and the size of the memory reserved to carry
>> the IMA measurement log.
>>
>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> 
> This patch removes two functions from arch/powerpc/kexec/ima.c, but adds
> four to security/integrity/ima/ima_kexec.c. The extra ones are
> get_addr_size_cells() and do_get_kexec_buffer(), which are being copied
> from the powerpc code but can't be removed yet because they're still
> used there by remove_ima_buffer() and setup_ima_buffer().
> 
> On the next patch you remove the need for these functions in powerpc
> code and therefore delete them. This confused me at first, so I think it
> would be cleared if you put patch 2 first in the series and then on this
> patch you can simply move the four functions and delete them from
> arch/powerpc/kexec/ima.c.
> 
> If you prefer to keep the current order, it's worth mentioning on the
> commit log where get_addr_size_cells() and do_get_kexec_buffer() are
> coming from.
> 
> Regardless:
> 
> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> 

Thanks for reviewing the changes Thiago.

I'll update the commit log to describe the changes related to 
get_addr_size_cells() and do_get_kexec_buffer().

  -lakshmi