grub2/0174-nx-set-the-nx-compatible-flag-in-EFI-grub-images.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Tue, 22 Mar 2022 10:57:20 -0400
Subject: [PATCH] nx: set the nx compatible flag in EFI grub images

For NX, we need the grub binary to announce that it is compatible with
the NX feature.  This implies that when loading the executable grub
image, several attributes are true:

- the binary doesn't need an executable stack
- the binary doesn't need sections to be both executable and writable
- the binary knows how to use the EFI Memory Attributes protocol on code
  it is loading.

This patch adds a definition for the PE DLL Characteristics flag
GRUB_PE32_NX_COMPAT, and changes grub-mkimage to set that flag.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 util/mkimage.c          | 1 +
 include/grub/efi/pe32.h | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/util/mkimage.c b/util/mkimage.c
index e2bb4d4cd05..425d920ff92 100644
--- a/util/mkimage.c
+++ b/util/mkimage.c
@@ -1438,6 +1438,7 @@ grub_install_generate_image (const char *dir, const char *prefix,
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdangling-pointer"
 #endif
+	PE_OHDR (o32, o64, dll_characteristics) = grub_host_to_target16 (GRUB_PE32_NX_COMPAT);
 	PE_OHDR (o32, o64, header_size) = grub_host_to_target32 (header_size);
 	PE_OHDR (o32, o64, entry_addr) = grub_host_to_target32 (layout.start_address);
 	PE_OHDR (o32, o64, image_base) = 0;
diff --git a/include/grub/efi/pe32.h b/include/grub/efi/pe32.h
index 4e6e9d254bd..9887e14b278 100644
--- a/include/grub/efi/pe32.h
+++ b/include/grub/efi/pe32.h
@@ -231,6 +231,8 @@ struct grub_pe64_optional_header
 
 #define GRUB_PE32_SUBSYSTEM_EFI_APPLICATION	10
 
+#define GRUB_PE32_NX_COMPAT	0x0100
+
 #define GRUB_PE32_NUM_DATA_DIRECTORIES	16
 
 struct grub_pe32_section_table