[PATCH] MdeModulePkg/DxeCore: base code protection on permission attributes

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Instead of assuming that a PE/COFF section of type EFI_IMAGE_SCN_CNT_CODE
can always be mapped read-only, classify a section as a code section only
if it has the executable attribute set and the writable attribute cleared.

This adheres more closely to the PE/COFF spec, and avoids issues with
Linux OS loaders that consists of a single read/write/execute section.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
index 1142dcc5a83d..3e037607a6be 100644
--- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
+++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
@@ -533,7 +533,7 @@ ProtectUefiImageCommon (
       Name[7]
       ));
 
-    if ((Section[Index].Characteristics & EFI_IMAGE_SCN_CNT_CODE) != 0) {
+    if ((Section[Index].Characteristics & (EFI_IMAGE_SCN_MEM_WRITE | EFI_IMAGE_SCN_MEM_EXECUTE)) == EFI_IMAGE_SCN_MEM_EXECUTE) {
       DEBUG ((DEBUG_VERBOSE, "  VirtualSize          - 0x%08x\n", Section[Index].Misc.VirtualSize));
       DEBUG ((DEBUG_VERBOSE, "  VirtualAddress       - 0x%08x\n", Section[Index].VirtualAddress));
       DEBUG ((DEBUG_VERBOSE, "  SizeOfRawData        - 0x%08x\n", Section[Index].SizeOfRawData));
-- 
2.7.4