Re: [PATCH v4 1/5] powerpc: Refactor kexec functions to move arch independent code to IMA

Lakshmi Ramasubramanian
2020-08-28T17:41:07Z

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