MdePkg/BasePrintLib: Do not do operations with NULL

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Harry Liebel <Harry.Liebel@arm.com>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>
Reviewed-by: Gao, Liming <liming.gao@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15646 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 14 insertions, 7 deletions

diff --git a/MdePkg/Library/BasePrintLib/PrintLibInternal.c b/MdePkg/Library/BasePrintLib/PrintLibInternal.c
index c4fd755eec..e61aed9fda 100644
--- a/MdePkg/Library/BasePrintLib/PrintLibInternal.c
+++ b/MdePkg/Library/BasePrintLib/PrintLibInternal.c
@@ -373,17 +373,21 @@ BasePrintLibSPrintMarker (
   }

 

   LengthToReturn = 0;

+  EndBuffer = NULL;

+  OriginalBuffer = NULL;

 

   //

   // Reserve space for the Null terminator.

   //

-  BufferSize--;

-  OriginalBuffer = Buffer;

+  if (Buffer != NULL) {

+    BufferSize--;

+    OriginalBuffer = Buffer;

 

-  //

-  // Set the tag for the end of the input Buffer.

-  //

-  EndBuffer      = Buffer + BufferSize * BytesPerOutputCharacter;

+    //

+    // Set the tag for the end of the input Buffer.

+    //

+    EndBuffer = Buffer + BufferSize * BytesPerOutputCharacter;

+  }

 

   if ((Flags & FORMAT_UNICODE) != 0) {

     //

@@ -411,7 +415,10 @@ BasePrintLibSPrintMarker (
   //

   // Loop until the end of the format string is reached or the output buffer is full

   //

-  while (FormatCharacter != 0 && Buffer < EndBuffer) {

+  while (FormatCharacter != 0) {

+    if ((Buffer != NULL) && (Buffer >= EndBuffer)) {

+      break;

+    }

     //

     // Clear all the flag bits except those that may have been passed in

     //