Comment 161 for bug 1040557

On Tue, Feb 26, 2013 at 05:51:40PM -0000, hanishkvc wrote:
> I have a query related to the FIx. Shouldn't the right fix for this bug
> if one wants to use secure boot and uefi to boot their system be the
> noefi boot param related fix added to linux kernels around 15th Feb i.e

Using a 'noefi' boot param is, in various senses, the exact opposite of what
we want for the samsung-laptop module. The samsung-laptop module needs to
know that it's running under uefi and not attempt to poke the firmware in
various spots - because doing so appears to result in a machine check
exception. Booting with 'noefi' should ensure the Linux kernel never
triggers the bricking bug in the samsung firmware, but it would also not
result in correct behavior.

> And if I get things correctly then passing noefi to linux kernel as a
> boot param will disable the use of efi runtime services by the kernel
> and its modules. And that is the 100% sure way of ensuring that under
> linux one cann't trigger this bug in the normal sense

Technically, I believe that this only prevents the *kernel* from using efi
runtime services but does not prevent user space from writing to the EFI
variable space as root. I could be wrong, though.