MdeModulePkg/FvSimpleFileSystem: fix assertions when FV is empty

The original code will assert when dealing with those empty FVs. The fix is used to solve this bug. Cc: Chao Zhang <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Feng Tian <[email protected]> Reviewed-by: Chao Zhang <[email protected]>
WalonLi · Aug 3, 2016 · ebd2be6 · ebd2be6
1 parent 846ea5f
commit ebd2be6
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/MdeModulePkg/Universal/FvSimpleFileSystemDxe/FvSimpleFileSystem.c b/MdeModulePkg/Universal/FvSimpleFileSystemDxe/FvSimpleFileSystem.c
@@ -526,7 +526,10 @@ FvSimpleFileSystemOpen (
     InitializeListHead (&NewFile->Link);
     InsertHeadList (&Instance->FileHead, &NewFile->Link);
 
-    NewFile->DirReadNext = FVFS_GET_FIRST_FILE_INFO (Instance);
+    NewFile->DirReadNext = NULL;
+    if (!IsListEmpty (&Instance->FileInfoHead)) {
+      NewFile->DirReadNext = FVFS_GET_FIRST_FILE_INFO (Instance);
+    }
 
     *NewHandle = &NewFile->FileProtocol;
     return EFI_SUCCESS;
@@ -821,7 +824,9 @@ FvSimpleFileSystemSetPosition (
     //
     // Reset directory position to first entry
     //
-    File->DirReadNext = FVFS_GET_FIRST_FILE_INFO (Instance);
+    if (File->DirReadNext) {
+      File->DirReadNext = FVFS_GET_FIRST_FILE_INFO (Instance); 
+    }
   } else if (Position == 0xFFFFFFFFFFFFFFFFull) {
     File->Position = File->FvFileInfo->FileInfo.FileSize;
   } else {

diff --git a/MdeModulePkg/Universal/FvSimpleFileSystemDxe/FvSimpleFileSystemEntryPoint.c b/MdeModulePkg/Universal/FvSimpleFileSystemDxe/FvSimpleFileSystemEntryPoint.c
@@ -223,7 +223,11 @@ FvSimpleFileSystemOpenVolume (
     }
   }
 
-  Instance->Root->DirReadNext = FVFS_GET_FIRST_FILE_INFO (Instance);
+  Instance->Root->DirReadNext = NULL;
+  if (!IsListEmpty (&Instance->FileInfoHead)) {
+    Instance->Root->DirReadNext = FVFS_GET_FIRST_FILE_INFO (Instance);
+  }
+
   *RootFile = &Instance->Root->FileProtocol;
   return Status;
 }