On Mon, Jan 14, 2019 at 04:27:17PM +0100, Alexander Graf wrote:
> In order to enforce NX semantics on non-code pages, UEFI firmware
> may require that all code is EFI_PAGE_SIZE (4k) aligned. A similar
> change has recently been applied to edk2 to accomodate for the same
> fact:
>
> https://lists.01.org/pipermail/edk2-devel/2018-December/033708.html
>
> This patch adapts grub to also implement the same alignment guarantees
> and thus ensures we can boot even when strict permission checks are in
> place.
>
> Signed-off-by: Alexander Graf <ag...@suse.de>
>
> ---
>
> v1 -> v2:
>
> - Mention only NX requirement in patch description
> - Use GRUB_EFI_PAGE_SIZE
>
> v2 -> v3:
>
> - Apply alignment to all architectures
> ---
> util/mkimage.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/util/mkimage.c b/util/mkimage.c
> index a670db456..6b372cba5 100644
> --- a/util/mkimage.c
> +++ b/util/mkimage.c
> @@ -39,6 +39,7 @@
> #include <string.h>
> #include <stdlib.h>
> #include <assert.h>
> +#include <grub/efi/memory.h>
> #include <grub/efi/pe32.h>
> #include <grub/uboot/image.h>
> #include <grub/arm/reloc.h>
> @@ -66,14 +67,14 @@
> + sizeof (struct grub_pe32_coff_header) \
> + sizeof (struct grub_pe32_optional_header)
> \
> + 4 * sizeof (struct
> grub_pe32_section_table), \
> - GRUB_PE32_SECTION_ALIGNMENT)
> + GRUB_EFI_PAGE_SIZE)
>
> #define EFI64_HEADER_SIZE ALIGN_UP (GRUB_PE32_MSDOS_STUB_SIZE
> \
> + GRUB_PE32_SIGNATURE_SIZE \
> + sizeof (struct grub_pe32_coff_header) \
> + sizeof (struct grub_pe64_optional_header)
> \
> + 4 * sizeof (struct
> grub_pe32_section_table), \
> - GRUB_PE32_SECTION_ALIGNMENT)
> + GRUB_EFI_PAGE_SIZE)
GRUB_PE32_SECTION_ALIGNMENT should be changed to GRUB_PE32_FILE_ALIGNMENT.
However, earlier GRUB_PE32_FILE_ALIGNMENT should be defined as 0x20. Yeah,
I know that this is contrary to the PE/COFF spec. Though everybody uses
that value. Even MS...
Then below in the util/mkimage.c some code should look more or less like that:
reloc_addr = ALIGN_UP (header_size + core_size,
GRUB_PE32_FILE_ALIGNMENT);
pe_size = ALIGN_UP (reloc_addr + layout.reloc_size,
GRUB_PE32_FILE_ALIGNMENT);
...and...
o->file_alignment = grub_host_to_target32 (GRUB_PE32_FILE_ALIGNMENT);
Last line should be changed at least in two places.
Daniel
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