MdeModulePkg/Core: fix feature conflict between NX and heap guard

[mirror_edk2.git] / MdeModulePkg / Core / Dxe / Misc / MemoryProtection.c

diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
index a4705bc7ce343f002fb933829e9cecfaa3ec7987..455ed35f9a36541272ea21effd7d13f23f5caf84 100644 (file)
--- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
+++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
@@ -48,6 +48,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Protocol/SimpleFileSystem.h>\r
 \r
 #include "DxeMain.h"\r
+#include "Mem/HeapGuard.h"\r
 \r
 #define CACHE_ATTRIBUTE_MASK   (EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP)\r
 #define MEMORY_ATTRIBUTE_MASK  (EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RO)\r
@@ -1202,6 +1203,27 @@ ApplyMemoryProtectionPolicy (
     return EFI_SUCCESS;\r
   }\r
 \r
+  //\r
+  // Don't overwrite Guard pages, which should be the first and/or last page,\r
+  // if any.\r
+  //\r
+  if (IsHeapGuardEnabled ()) {\r
+    if (IsGuardPage (Memory))  {\r
+      Memory += EFI_PAGE_SIZE;\r
+      Length -= EFI_PAGE_SIZE;\r
+      if (Length == 0) {\r
+        return EFI_SUCCESS;\r
+      }\r
+    }\r
+\r
+    if (IsGuardPage (Memory + Length - EFI_PAGE_SIZE))  {\r
+      Length -= EFI_PAGE_SIZE;\r
+      if (Length == 0) {\r
+        return EFI_SUCCESS;\r
+      }\r
+    }\r
+  }\r
+\r
   //\r
   // Update the executable permissions according to the DXE memory\r
   // protection policy, but only if\r