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

[Lakshmi Ramasubramanian]

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