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 <address@hidden>
---
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.