From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <[email protected]>
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 <[email protected]>
(cherry picked from commit 0c7f1aed5a87f75051b421903a900ccb4bbd795a)
(cherry picked from commit 2f9446d488da96de963f4ffe03b0a1c60a4664f5)
[rharwood: fix uninitialized use of stack_attrs]
Signed-off-by: Robbie Harwood <[email protected]>
---
 util/mkimage.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/util/mkimage.c b/util/mkimage.c
index 16418e245d..c77025904c 100644
--- a/util/mkimage.c
+++ b/util/mkimage.c
@@ -1358,6 +1358,7 @@ grub_install_generate_image (const char *dir, const char *prefix,
 	    section = (struct grub_pe32_section_table *)(o64 + 1);
 	  }
 
+	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;