Re: [PATCH v8 2/4] powerpc: Refactor kexec functions to move arch independent code to ima

From: Mimi Zohar <zohar@linux.ibm.com>
To: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
	bauerman@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
Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, prsriva@linux.microsoft.com,
	balajib@linux.microsoft.com
Subject: Re: [PATCH v8 2/4] powerpc: Refactor kexec functions to move arch independent code to ima
Date: Tue, 03 Nov 2020 14:50:21 -0500	[thread overview]
Message-ID: <f45e865c005ce05a6bc376e14c089937197e2aeb.camel@linux.ibm.com> (raw)
In-Reply-To: <397f1bbf-46bf-b522-616b-2e006ef30e70@linux.microsoft.com>

On Tue, 2020-11-03 at 11:23 -0800, Lakshmi Ramasubramanian wrote:
> On 11/3/20 6:55 AM, Mimi Zohar wrote:
> 
> Hi Mimi,
> 
> > 
> > On Fri, 2020-10-30 at 10:44 -0700, Lakshmi Ramasubramanian wrote:
> >> 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 ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
> >> subsystem. A later patch in this series will use these functions for
> >> carrying forward the IMA measurement log for ARM64.
> >>
> >> With the above refactoring arch/powerpc/kexec/ima.c contains only
> >> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
> >> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
> >> when CONFIG_IMA_KEXEC is enabled.
> >>
> >> 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>
> > 
> > Similar comments to 1/4.
> > -  Last line of first paragraph can be rephrased like " ... on kexec,
> > do not contain architecture specific code, but are currently limited to
> > powerpc."
> Sure.
> 
> > -  This patch should be limited to moving existing functions.
> > Truncate the Subject line to "Move arch independent IMA kexec functions
> > to ima_kexec.c."
> Will do.
> 
> > - Don't refer to a later patch, but explain the purpose here.  For
> > example, "Move ... , making them accessible to other archs."
> Sure.
> 
> > - The definition of "FDT_PROP_IMA_KEXEC_BUFFER" should be made as a
> > separate, prepartory patch, prior to the existing 1/4.  The resulting
> > code being moved in this patch (and similarly for 1/4) will be exactly
> > the same as the code being deleted.
> 
> Definition of FDT_PROP_IMA_KEXEC_BUFFER will be made as a preparatory 
> patch as you'd mentioned in the comments for [PATCH 1/4].
> 
> Will split [PATCH 2/4] as listed below:
> 
> PATCH #1: Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to 
> IMA, along with deleting them in arch/powerpc/kexec/ima.c

No, other than the comments above, this patch is fine.  It moves
ima_get_kexec_buffer() and ima_free_kexec_buffer() to ima_kexec.c.

Mimi