[RFC PATCH v2 1/7] MdePkg: Update MemoryAttributesTable to v2.10

["Ard Biesheuvel" <ardb@kernel.org>]

UEFI v2.10 introduces a new flag to the memory attributes table to
inform the OS whether or not runtime services code regions were emitted
by the compiler with guard instructions for forward edge control flow
integrity enforcement.

So update our definition accordingly.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Acked-by: Michael Kubacki <michael.kubacki@microsoft.com>
---
 MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c | 2 +-
 MdePkg/Include/Guid/MemoryAttributesTable.h        | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c b/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
index e07921371187..82fa026bceb9 100644
--- a/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
+++ b/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
@@ -182,7 +182,7 @@ InstallMemoryAttributesTable (
   MemoryAttributesTable->Version         = EFI_MEMORY_ATTRIBUTES_TABLE_VERSION;
   MemoryAttributesTable->NumberOfEntries = RuntimeEntryCount;
   MemoryAttributesTable->DescriptorSize  = (UINT32)DescriptorSize;
-  MemoryAttributesTable->Reserved        = 0;
+  MemoryAttributesTable->Flags           = 0;
   DEBUG ((DEBUG_VERBOSE, "MemoryAttributesTable:\n"));
   DEBUG ((DEBUG_VERBOSE, "  Version              - 0x%08x\n", MemoryAttributesTable->Version));
   DEBUG ((DEBUG_VERBOSE, "  NumberOfEntries      - 0x%08x\n", MemoryAttributesTable->NumberOfEntries));
diff --git a/MdePkg/Include/Guid/MemoryAttributesTable.h b/MdePkg/Include/Guid/MemoryAttributesTable.h
index 82f83a67b96d..238c14ff92df 100644
--- a/MdePkg/Include/Guid/MemoryAttributesTable.h
+++ b/MdePkg/Include/Guid/MemoryAttributesTable.h
@@ -17,11 +17,15 @@ typedef struct {
   UINT32    Version;
   UINT32    NumberOfEntries;
   UINT32    DescriptorSize;
-  UINT32    Reserved;
+  UINT32    Flags;
   // EFI_MEMORY_DESCRIPTOR Entry[1];
 } EFI_MEMORY_ATTRIBUTES_TABLE;
 
-#define EFI_MEMORY_ATTRIBUTES_TABLE_VERSION  0x00000001
+#define EFI_MEMORY_ATTRIBUTES_TABLE_VERSION  0x00000002
+
+#define EFI_MEMORY_ATTRIBUTES_FLAGS_RT_FORWARD_CONTROL_FLOW_GUARD  0x1
+// BIT0 implies that Runtime code includes the forward control flow guard
+// instruction, such as X86 CET-IBT or ARM BTI.
 
 extern EFI_GUID  gEfiMemoryAttributesTableGuid;
 
-- 
2.39.1