Re: [PATCH v13 2/6] powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c

Lakshmi Ramasubramanian
2020-12-22T18:54:28Z

On 12/22/20 6:26 AM, Mimi Zohar wrote:

Hi Mimi,

>
> On Sat, 2020-12-19 at 09:57 -0800, Lakshmi Ramasubramanian wrote:
>>
>> diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
>> index 4aff6846c772..b6c52608cb49 100644
>> --- a/arch/powerpc/kexec/Makefile
>> +++ b/arch/powerpc/kexec/Makefile
>> @@ -9,13 +9,6 @@ obj-$(CONFIG_PPC32) += relocate_32.o
>>
>> obj-$(CONFIG_KEXEC_FILE) += file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
>>
>> -ifdef CONFIG_HAVE_IMA_KEXEC
>> -ifdef CONFIG_IMA
>> -obj-y += ima.o
>> -endif
>> -endif
>
> Notice how "kexec/ima.o" is only included if the architecture supports
> it and IMA is configured. In addition only if CONFIG_IMA_KEXEC is
> configured, is the IMA measurement list carried across kexec. After
> moving the rest of ima.c to drivers/of/kexec.c, this changes. Notice
> how drivers/of/Kconfig includes kexec.o:
>
> obj-$(CONFIG_KEXEC_FILE) += kexec.o
>
> It is not dependent on CONFIG_HAVE_IMA_KEXEC. Shouldn't all of the
> functions defined in ima.c being moved to kexec.o be defined within a
> CONFIG_HAVE_IMA_KEXEC ifdef?
>

Thanks for reviewing the changes.

In "drivers/of/kexec.c" the function remove_ima_buffer() is defined
under "#ifdef CONFIG_HAVE_IMA_KEXEC"

setup_ima_buffer() is defined under "#ifdef CONFIG_IMA_KEXEC" - the same
way it was defined in "arch/powerpc/kexec/ima.c".

As you know, CONFIG_IMA_KEXEC depends on CONFIG_HAVE_IMA_KEXEC (as
defined in "security/integrity/ima/Kconfig").

ima_get_kexec_buffer() and ima_free_kexec_buffer() are unconditionally
defined in "drivers/of/kexec.c" even though they are called only when
CONFIG_HAVE_IMA_KEXEC is enabled. I will update these two functions to
be moved under "#ifdef CONFIG_HAVE_IMA_KEXEC"

Rob/Mimi/Thiago - Please let me know if you have other comments in the
v13 patches. Will address those as well and post v14.

thanks,
-lakshmi