ArmPkg: ArmExceptionLib: Fixing exception vector and type casting

The current VectorBase is taking value from a 64bit PCD into a UINTN
value, which could have truncated value for 32bit system.

In addition, the comparison between UINTN and INTN could lead to
undesired comparison outcome or compiler complaints.

This change updates all of them to be UINT64 based operation.

Cc: Leif Lindholm <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Sami Mujawar <[email protected]>

Signed-off-by: Kun Qin <[email protected]>

ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c

@@ -91,7 +91,7 @@ InitializeCpuExceptionHandlers (
   )
 {
   RETURN_STATUS  Status;
-  UINTN          VectorBase;
+  UINT64         VectorBase;
 
   Status = EFI_SUCCESS;
 
@@ -113,17 +113,17 @@ InitializeCpuExceptionHandlers (
 
     // We do not copy the Exception Table at PcdGet64(PcdCpuVectorBaseAddress). We just set Vector
     // Base Address to point into CpuDxe code.
-    VectorBase = (UINTN)ExceptionHandlersStart;
+    VectorBase = (UINT64)(UINTN)ExceptionHandlersStart;
 
     Status = RETURN_SUCCESS;
   }
 
   if (!RETURN_ERROR (Status)) {
     // call the architecture-specific routine to prepare for the new vector
     // configuration to take effect
-    ArchVectorConfig (VectorBase);
+    ArchVectorConfig ((UINTN)VectorBase);
 
-    ArmWriteVBar (VectorBase);
+    ArmWriteVBar ((UINTN)VectorBase);
   }
 
   return RETURN_SUCCESS;
@@ -172,7 +172,7 @@ CopyExceptionHandlers (
   }
 
   // Copy our assembly code into the page that contains the exception vectors.
-  CopyMem ((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);
+  CopyMem ((VOID *)VectorBase, (VOID *)(UINTN)ExceptionHandlersStart, Length);
 
   //
   // Initialize the C entry points for interrupts
@@ -226,7 +226,7 @@ RegisterCpuInterruptHandler (
   IN EFI_CPU_INTERRUPT_HANDLER  ExceptionHandler
   )
 {
-  if (ExceptionType > gMaxExceptionNumber) {
+  if ((UINTN)ExceptionType > gMaxExceptionNumber) {
     return RETURN_UNSUPPORTED;
   }
 
@@ -273,7 +273,7 @@ CommonCExceptionHandler (
   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
   )
 {
-  if (ExceptionType <= gMaxExceptionNumber) {
+  if ((UINTN)ExceptionType <= gMaxExceptionNumber) {
     if (gExceptionHandlers[ExceptionType]) {
       gExceptionHandlers[ExceptionType](ExceptionType, SystemContext);
       return;