Re: [PATCH 4/6] efi: Get the secure boot status

From: Lukas Wunner
Date: Tue Nov 22 2016 - 15:35:07 EST


On Tue, Nov 22, 2016 at 02:52:01PM +0000, David Howells wrote:
> Lukas Wunner <lukas@xxxxxxxxx> wrote:
> > You dropped the efi_system_table_t *sys_table_arg argument but this
> > isn't defined anywhere as a static global.
>
> It seems to me that passing this value in on x86 is probably a bad idea as
> it's not mixed-mode safe. Should I just pass NULL there in that case?

It's safe, it's merely a pointer below 4 Gig. Just on dereference it
needs to be cast to the correct variant. Passing in sys_table_arg is
done all over the place in the EFI stub, see e.g. efi_printk().

Best regards,

Lukas