MdeModulePkg/DxeIpl: Implement NULL pointer detection

[mirror_edk2.git] / MdeModulePkg / Core / DxeIplPeim / Ia32 / DxeLoadFunc.c

diff --git a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c
index 1957326caf6247f0cde76d316e34952cb3d5837d..96f57184447061b02831ac09cf755e857fcbb7b8 100644 (file)
--- a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c
+++ b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c
@@ -123,7 +123,9 @@ Create4GPageTablesIa32Pae (
     PageDirectoryPointerEntry->Bits.Present = 1;\r
 \r
     for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress += SIZE_2MB) {\r
-      if ((PhysicalAddress < StackBase + StackSize) && ((PhysicalAddress + SIZE_2MB) > StackBase)) {\r
+      if ((IsNullDetectionEnabled () && PhysicalAddress == 0)\r
+          || ((PhysicalAddress < StackBase + StackSize)\r
+              && ((PhysicalAddress + SIZE_2MB) > StackBase))) {\r
         //\r
         // Need to split this 2M page that covers stack range.\r
         //\r
@@ -240,6 +242,10 @@ HandOffToDxeCore (
   EFI_PEI_VECTOR_HANDOFF_INFO_PPI *VectorHandoffInfoPpi;\r
   BOOLEAN                   BuildPageTablesIa32Pae;\r
 \r
+  if (IsNullDetectionEnabled ()) {\r
+    ClearFirst4KPage (HobList.Raw);\r
+  }\r
+\r
   Status = PeiServicesAllocatePages (EfiBootServicesData, EFI_SIZE_TO_PAGES (STACK_SIZE), &BaseOfStack);\r
   ASSERT_EFI_ERROR (Status);\r
 \r
@@ -379,10 +385,15 @@ HandOffToDxeCore (
     TopOfStack = (EFI_PHYSICAL_ADDRESS) (UINTN) ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);\r
 \r
     PageTables = 0;\r
-    BuildPageTablesIa32Pae = (BOOLEAN) (PcdGetBool (PcdSetNxForStack) && IsIa32PaeSupport () && IsExecuteDisableBitAvailable ());\r
+    BuildPageTablesIa32Pae = (BOOLEAN) (IsIa32PaeSupport () &&\r
+                                        (IsNullDetectionEnabled () ||\r
+                                         (PcdGetBool (PcdSetNxForStack) &&\r
+                                          IsExecuteDisableBitAvailable ())));\r
     if (BuildPageTablesIa32Pae) {\r
       PageTables = Create4GPageTablesIa32Pae (BaseOfStack, STACK_SIZE);\r
-      EnableExecuteDisableBit ();\r
+      if (IsExecuteDisableBitAvailable ()) {\r
+        EnableExecuteDisableBit();\r
+      }\r
     }\r
 \r
     //\r