Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

Mimi Zohar
2021-02-10T20:58:02Z

On Wed, 2021-02-10 at 14:42 -0600, Rob Herring wrote:
> On Wed, Feb 10, 2021 at 11:33 AM Lakshmi Ramasubramanian
> <nramas@linux.microsoft.com> wrote:
> >
> > On 2/10/21 9:15 AM, Rob Herring wrote:
> > > On Tue, Feb 09, 2021 at 10:21:50AM -0800, Lakshmi Ramasubramanian wrote:
> > >> On kexec file load Integrity Measurement Architecture (IMA) subsystem
> > >> may verify the IMA signature of the kernel and initramfs, and measure
> > >> it. The command line parameters passed to the kernel in the kexec call
> > >> may also be measured by IMA. A remote attestation service can verify
> > >> a TPM quote based on the TPM event log, the IMA measurement list, and
> > >> the TPM PCR data. This can be achieved only if the IMA measurement log
> > >> is carried over from the current kernel to the next kernel across
> > >> the kexec call.
> > >>
> > >> powerpc already supports carrying forward the IMA measurement log on
> > >> kexec. This patch set adds support for carrying forward the IMA
> > >> measurement log on kexec on ARM64.
> > >>
> > >> This patch set moves the platform independent code defined for powerpc
> > >> such that it can be reused for other platforms as well. A chosen node
> > >> "linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
> > >> the address and the size of the memory reserved to carry
> > >> the IMA measurement log.
> > >>
> > >> This patch set has been tested for ARM64 platform using QEMU.
> > >> I would like help from the community for testing this change on powerpc.
> > >> Thanks.
> > >>
> > >> This patch set is based on
> > >> commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
> > >> in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
> > >> "next-integrity" branch.
> > >
> > > Is that a hard dependency still? Given this is now almost entirely
> > > deleting arch code and adding drivers/of/ code, I was going to apply it.
> > >
> >
> > I tried applying the patches in Linus' mainline branch -
> > PATCH #5 0005-powerpc-Move-ima-buffer-fields-to-struct-kimage.patch
> > doesn't apply.
> >
> > But if I apply the dependent patch set (link given below), all the
> > patches in this patch set apply fine.
> >
> > https://patchwork.kernel.org/project/linux-integrity/patch/20210204174951.25771-2-nramas@linux.microsoft.com/
>
> Ideally, we don't apply the same patch in 2 branches. It looks like
> there's a conflict but no real dependence on the above patch (the
> ima_buffer part). The conflict seems trivial enough that Linus can
> resolve it in the merge window.
>
> Or Mimi can take the whole thing if preferred?

How about I create a topic branch with just the two patches, allowing
both of us to merge it? There shouldn't be a problem with re-writing
next-integrity history.

Mimi