Re: [PATCH 9/9] module: Reorder functions

[Ard Biesheuvel]

On Mon, 20 Apr 2020 at 15:37, Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> wrote:
>
> On 4/20/2020 5:01 AM, Ard Biesheuvel wrote:
> > Is that the only prerequisite? I.e., is it sufficient for another
> > architecture to add -ffunction-sections to the module CFLAGS to get
> > this functionality? (assuming it defines CONFIG_FG_KASLR=y)
>
> I suspect you also need/want at least normal KASLR enabled as
> a "does it even make sense" common sense threshold

Fair enough. But that is more of a policy concern than a functional concern.

FWIW I took patches #8 and #9, hardwired a couple of CONFIG_FG_KASLR=y
checks and added the -ffunction-sections GCC option for the modules,
and everything appears to be working as expected on arm64. I was just
wondering if I was missing something.

Note that arm64 does not have a decompressor, so there the fine
grained randomization of the core kernel is not really feasible using
the approach presented here.