SecurityPkg: Tcg2Smm: Refine type cast in pointer abstraction

Pointer subtraction is not performed by pointers to elements of the same
array object. Such behavior is undefined by C11 standard and might lead to
potential issues, Refine pointer subtraction by first casting each pointer
to UINTN.

Cc: Hao Wu <hao.a.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Hao Wu <hao.a.wu@intel.com>

diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
index 6eb62ae64ca3c7ec49ce158b045885c2aea81b1d..c3cee834ae8dbb6d65cc47bec21d36ba5814391b 100644 (file)
--- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
+++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
@@ -543,7 +543,7 @@ UpdatePossibleResource (
   //\r
   DataPtr += 2;\r
   if (DataPtr < DataEndPtr) {\r
-    SetMem(DataPtr, (UINTN)(DataEndPtr - DataPtr), AML_NOOP_OP);\r
+    SetMem(DataPtr, (UINTN)DataEndPtr - (UINTN)DataPtr, AML_NOOP_OP);\r
   }\r
 \r
   return EFI_SUCCESS;\r