Messages in this thread | | | Subject | Re: LockDown that allows read of /dev/mem ? | From | "Enrico Weigelt, metux IT consult" <> | Date | Fri, 2 Jul 2021 09:42:31 +0200 |
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On 21.06.21 17:29, David F. wrote:
Hi,
> Lockdown required by secure boot and shim signing (prevent acpi > patching), root because it's main use is a utility boot disk. If > lockdown could be forced when secure boot active but not when not > active, that be best, but I'm not seeing that option. The other > option maybe to modify open_port on mem.c to do the secure boot check. > However searching EFI_SECURE_BOOT doesn't exist in 5.10.x as in > efi_enabled(EFI_SECURE_BOOT) - It appears that is some other patch > that is not applied to the base, I do see struct boot_params has a > secure_boot field set, but can I access that from mem.c? If not, is > efi_get_secureboot() function available when /drivers/char/mem.c may > be used?
I'd rather try not using /dev/mem at all.
What exactly do you really need it for, in that specific case ?
--mtx
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