Re: [PATCH v4 10/10] module: Reorder functions

From: Jessica Yu
Date: Tue Jul 28 2020 - 13:29:16 EST

+++ Kristen Carlson Accardi [17/07/20 10:00 -0700]:
Introduce a new config option to allow modules to be re-ordered
by function. This option can be enabled independently of the
kernel text KASLR or FG_KASLR settings so that it can be used
by architectures that do not support either of these features.
This option will be selected by default if CONFIG_FG_KASLR is

If a module has functions split out into separate text sections
(i.e. compiled with the -ffunction-sections flag), reorder the
functions to provide some code diversification to modules.

Signed-off-by: Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Tested-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Tested-by: Tony Luck <tony.luck@xxxxxxxxx>

Hi Kristen!

I've boot tested this on x86, (un)loaded some modules, and checked
their resulting section addresses as a quick sanity test. Feel free
to add my:

Acked-by: Jessica Yu <jeyu@xxxxxxxxxx>
Tested-by: Jessica Yu <jeyu@xxxxxxxxxx>

Thank you!