Re: [PATCH 17/24] acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down

[David Howells]

Dave Young <dyoung@xxxxxxxxxx> wrote:

> > > This option allows userspace to pass the RSDP address to the kernel, which
> > > makes it possible for a user to circumvent any restrictions imposed on
> > > loading modules.  Ignore the option when the kernel is locked down.
> > 
> > I'm not really sure here.
> > 
> > What exactly is the mechanism?
> 
> Actually this acpi_rsdp param is created for EFI kexec reboot in old
> days when we had not supported persistent efi vm space across kexec
> reboot. At that time kexec reboot runs as noefi mode, it can not find
> the acpi root table thus kernel will hang early.
> 
> Now kexec can support EFI boot so this param is not necessary for most
> user unless they still use efi=old_map.

Is this patch now unnecessary?

David