Re: [PATCHv2 1/3] x86, ptdump: Add section for EFI runtime services

From: Borislav Petkov
Date: Tue Oct 28 2014 - 14:58:06 EST


On Sun, Oct 12, 2014 at 02:55:15PM +0200, Mathias Krause wrote:

...

> There's a lengthy comment in arch/x86/platform/efi/efi.c that mentions
> the duplication of pgd entries -- and therefore whole hierarchies --
> between trampoline_pgd and init_level4_pgt. And, ironically, that
> comment is yours from earlier this year. Looks like you forgot about
> that in the meantime ;)

Absolutely - you can see how crazy I am about UEFI :-)

Ok, thanks for refreshing this for me, your patch is good, so

Acked-by: Borislav Petkov <bp@xxxxxxx>

What this whole story shows, however, is that the EFI mappings are in
fact in the kernel page table and this shouldn't be IMO - I'd like to
very much have them split because otherwise there's no need to switch
page tables at all. And besides, having UEFI in its own address space is
a good thing in itself anyway.

So, I've already hacked up something to have a completely separate EFI
page table - need to find out why it doesn't work yet but qemu was
b0rked until recently so we had to deal with that first... bla bla.

Thanks :-)

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/