x86/boot/compressed/64: Always switch to own page table

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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 the kernel 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.

 [ bp: Massage commit message. ]

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200907131613.12703-17-joro@8bytes.org

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This commit is contained in:

Joerg Roedel 2020-09-07 15:15:17 +02:00 • committed by Borislav Petkov

parent 8b0d3b3b41

commit ca0e22d4f0

3 changed files with 32 additions and 25 deletions

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3

arch/x86/boot/compressed/head_64.S

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51

arch/x86/boot/compressed/ident_map_64.c

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3

arch/x86/boot/compressed/kaslr.c

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