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 <chao.b.zhang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Chao Zhang <chao.b.zhang@intel.com>

2 files changed, 12 insertions, 3 deletions

diff --git a/MdeModulePkg/Universal/FvSimpleFileSystemDxe/FvSimpleFileSystem.c b/MdeModulePkg/Universal/FvSimpleFileSystemDxe/FvSimpleFileSystem.c
index c6137aca1f..b81110ff98 100644
--- 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
index 7167fb950b..4e6089b057 100644
--- 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;

 }