Re: [PATCH v4 15/75] x86/boot/compressed/64: Always switch to own page-table

Kees Cook
2020-07-15T01:23:51Z

On Tue, Jul 14, 2020 at 02:08:17PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
>
> When booted through startup_64 the kernel keeps running on the EFI
> page-table until the KASLR code sets up its own page-table. Without
> KASLR the pre-decompression boot code never switches off the EFI
> page-table. Change that by unconditionally switching to a kernel
> controlled page-table after relocation.
>
> This makes sure we can make changes to the mapping when necessary, for
> example map pages unencrypted in SEV and SEV-ES guests.
>
> Also remove the debug_putstr() calls in initialize_identity_maps()
> because the function now runs before console_init() is called.
>
> Signed-off-by: Joerg Roedel <jroedel@suse.de>

Reviewed-by: Kees Cook <keescook@chromium.org>

--
Kees Cook