Re: [PATCH] x86/setup: fix low identity map for >= 2GB kernel range

From: Krzysztof Mazur
Date: Fri Nov 06 2015 - 09:11:46 EST


On Fri, Nov 06, 2015 at 02:27:33PM +0100, Borislav Petkov wrote:
> On Fri, Nov 06, 2015 at 02:18:36PM +0100, Krzysztof Mazur wrote:
> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> > index a3cccbf..37c8ea8 100644
> > --- a/arch/x86/kernel/setup.c
> > +++ b/arch/x86/kernel/setup.c
> > @@ -1180,7 +1180,7 @@ void __init setup_arch(char **cmdline_p)
> > */
> > clone_pgd_range(initial_page_table,
> > swapper_pg_dir + KERNEL_PGD_BOUNDARY,
> > - KERNEL_PGD_PTRS);
> > + min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
> > #endif
> >
> > tboot_probe();
>
> http://git.kernel.org/tip/1c5dac914794f0170e1582d8ffdee52d30e0e4dd
>

Thanks and sorry. Yes, it has been already fixed. I've rechecked only
mainline.

However, I think that there should be
min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY), not just KERNEL_PGD_BOUNDARY
(usually 768 for normal 1G/3G split), because swapper_pg_dir has only
1024 entries and 768+768 is 1536.

Krzysiek
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