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

From: Lakshmi Ramasubramanian
Date: Tue Nov 03 2020 - 15:05:28 EST


On 11/3/20 11:50 AM, Mimi Zohar wrote:
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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Prakhar Srivastava <prsriva@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>

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.


Ok - I will do the updates in the patch description only and keep the code changes as is. Thanks for clarifying.

-lakshmi