[edk2-platforms][PATCH V4 8/8] Platform/Loongson: Enable zero address protection.

["xianglai" <lixianglai@loongson.cn>]

Set the 0 page property to unreadable, non-writable, non-executable

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Chao Li <lichao@loongson.cn>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: xianglai li <lixianglai@loongson.cn>
---
 .../LoongArchQemuPkg/Library/MmuLib/MmuBaseLibPei.inf     | 2 ++
 .../Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCore.c | 8 +++++++-
 .../LoongArchQemuPkg/Library/MmuLib/MmuLibCorePei.c       | 5 +++++
 Platform/Loongson/LoongArchQemuPkg/Loongson.dsc           | 2 ++
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuBaseLibPei.inf b/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuBaseLibPei.inf
index 12848eecfe..d7ab37eea4 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuBaseLibPei.inf
+++ b/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuBaseLibPei.inf
@@ -28,6 +28,7 @@
   MdePkg/MdePkg.dec
   Platform/Loongson/LoongArchQemuPkg/Loongson.dec
   OvmfPkg/OvmfPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
 
 [PCD]
   gLoongArchQemuPkgTokenSpaceGuid.PcdSwapPageDir
@@ -38,6 +39,7 @@
   gLoongArchQemuPkgTokenSpaceGuid.PcdFlashSecFvSize
   gLoongArchQemuPkgTokenSpaceGuid.PcdFlashSecFvBase
   gLoongArchQemuPkgTokenSpaceGuid.PcdRamSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
 
 [LibraryClasses]
   MemoryAllocationLib
diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCore.c b/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCore.c
index dac38c63f2..a45bcbdb6d 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCore.c
+++ b/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCore.c
@@ -735,10 +735,16 @@ EfiAttributeToLoongArchAttribute (
   }
 
   // Write protection attributes
-  if ((EfiAttributes & EFI_MEMORY_RO) != 0) {
+  if (((EfiAttributes & EFI_MEMORY_RO) != 0) ||
+      ((EfiAttributes & EFI_MEMORY_WP) != 0))
+  {
     LoongArchAttributes &= ~PAGE_DIRTY;
   }
 
+  if (EfiAttributes & EFI_MEMORY_RP) {
+    LoongArchAttributes |= PAGE_NO_READ;
+  }
+
   //eXecute protection attribute
   if ((EfiAttributes & EFI_MEMORY_XP) != 0) {
     LoongArchAttributes |= PAGE_NO_EXEC;
diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCorePei.c b/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCorePei.c
index 32a7fc0beb..a21233e796 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCorePei.c
+++ b/Platform/Loongson/LoongArchQemuPkg/Library/MmuLib/MmuLibCorePei.c
@@ -21,6 +21,7 @@
 #include <Library/QemuFwCfgLib.h>
 #include "MmuLibCore.h"
 #include <Library/CacheMaintenanceLib.h>
+#include <Library/MmuLib.h>
 
 /**
   Return the Virtual Memory Map of your platform
@@ -170,6 +171,10 @@ ConfigureMmu (VOID)
     MemoryTable++;
   }
 
+  if (PcdGet8 (PcdNullPointerDetectionPropertyMask) & BIT0) {
+    LoongArchSetMemoryAttributes (0, EFI_PAGE_SIZE, EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_WP);
+  }
+
   TlbReEntry = AllocatePages (1);
   if (TlbReEntry == NULL) {
     goto FreeTranslationTable;
diff --git a/Platform/Loongson/LoongArchQemuPkg/Loongson.dsc b/Platform/Loongson/LoongArchQemuPkg/Loongson.dsc
index 05913db144..13145cf051 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Loongson.dsc
+++ b/Platform/Loongson/LoongArchQemuPkg/Loongson.dsc
@@ -365,6 +365,8 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize         | 0x40000
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize       | 0x40000
 
+  gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask   | 1
+
 ################################################################################
 #
 # Pcd Dynamic Section - list of all EDK II PCD Entries defined by this Platform
-- 
2.31.1