Re: [GIT PULL] x86/boot changes for v6.10
From: Ingo Molnar
Date: Wed May 15 2024 - 04:10:06 EST
* Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
> On Tue, 14 May 2024 at 03:03, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Sun, 12 May 2024 at 23:51, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> > >
> > > - Re-introduce a bootloader quirk wrt. CR4 handling
> >
> > I've pulled this, but shouldn't the compressed boot also just stop
> > setting the G flag that it didn't understand?
> >
>
> I agree. But not setting CR4 to a known value is what caused the
> regression, and that could cause other problems down the road, so
> fixing it was arguably more important.
>
> More than happy to send another patch to clear the G bit from the page
> table entries created by the decompressor, but at this point, it
> shouldn't make a difference.
Please - we shouldn't be creating page table entries with random G bits set
in them. The boot code should at least pretend to maintain the illusion
that it knows what it's doing. ;-)
Thanks,
Ingo