Re: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

[Peter Zijlstra]

On Thu, Sep 06, 2018 at 04:27:48PM -0700, Sai Praneeth Prakhya wrote:
> From: Sai Praneeth <sai.praneeth.prakhya@xxxxxxxxx>
> 
> There may exist some buggy UEFI firmware implementations that might
> access efi regions other than EFI_RUNTIME_SERVICES_<CODE/DATA> even
> after the kernel has assumed control of the platform. This violates UEFI
> specification.
> 
> If selected, this debug option will print a warning message if the UEFI
> firmware tries to access any memory region which it shouldn't. Along
> with the warning, the efi page fault handler will also try to recover
> from the page fault triggered by the firmware so that the machine
> doesn't hang.

Why make this optional?