Re: [PATCH v4 05/29] x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables()

From: Borislav Petkov
Date: Mon Jun 27 2016 - 03:19:30 EST


Andy Lutomirski <luto@xxxxxxxxxx> wrote:

>kernel_unmap_pages_in_pgd() is dangerous: if a pgd entry in
>init_mm.pgd were to be cleared, callers would need to ensure that
>the pgd entry hadn't been propagated to any other pgd.
>
>Its only caller was efi_cleanup_page_tables(), and that, in turn,
>was unused, so just delete both functions. This leaves a couple of
>other helpers unused, so delete them, too.
>
>Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
>Cc: linux-efi@xxxxxxxxxxxxxxx
>Reviewed-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
>Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
>---
> arch/x86/include/asm/efi.h | 1 -
> arch/x86/include/asm/pgtable_types.h | 2 --
> arch/x86/mm/pageattr.c | 28 ----------------------------
> arch/x86/platform/efi/efi.c | 2 --
> arch/x86/platform/efi/efi_32.c | 3 ---
> arch/x86/platform/efi/efi_64.c | 5 -----
> 6 files changed, 41 deletions(-)

Acked-by: Borislav Petkov <bp@xxxxxxx>

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