[PATCH v2] ima: defer arch_ima_get_secureboot() call to IMA init time

[Mimi Zohar]

[Cc'ing linuxppc-dev at lists.ozlabs.org]

On Tue, 2020-10-13 at 10:18 +0200, Ard Biesheuvel wrote:
> Chester reports that it is necessary to introduce a new way to pass
> the EFI secure boot status between the EFI stub and the core kernel
> on ARM systems. The usual way of obtaining this information is by
> checking the SecureBoot and SetupMode EFI variables, but this can
> only be done after the EFI variable workqueue is created, which
> occurs in a subsys_initcall(), whereas arch_ima_get_secureboot()
> is called much earlier by the IMA framework.
> 
> However, the IMA framework itself is started as a late_initcall,
> and the only reason the call to arch_ima_get_secureboot() occurs
> so early is because it happens in the context of a __setup()
> callback that parses the ima_appraise= command line parameter.
> 
> So let's refactor this code a little bit, by using a core_param()
> callback to capture the command line argument, and deferring any
> reasoning based on its contents to the IMA init routine.
> 
> Cc: Chester Lin <clin at suse.com>
> Cc: Mimi Zohar <zohar at linux.ibm.com>
> Cc: Dmitry Kasatkin <dmitry.kasatkin at gmail.com>
> Cc: James Morris <jmorris at namei.org>
> Cc: "Serge E. Hallyn" <serge at hallyn.com>
> Link: https://lore.kernel.org/linux-arm-kernel/20200904072905.25332-2-clin@suse.com/
> Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
> ---
> v2: rebase onto series 'integrity: improve user feedback for invalid bootparams'

Thanks, Ard.  Based on my initial, limited testing on Power, it looks
good, but I'm hesistant to include it in the integrity 5.10 pull
request without it having been in linux-next and some additional
testing.  It's now queued in the next-integrity-testing branch awaiting
some tags.

thanks,

Mimi