MdeModulePkg: Add extra RestoreTpl() call in DiskIo

Adds a call to RestoreTpl() in DiskIo2ReadWriteDisk(). While the current
implementation does not technically violate spec on raise/restore TPL,
this extra call ensures symmetry between RaiseTpl and RestoreTpl calls,
which makes analysis of TPL correctness simpler and permits certain
non-standard TPL usages that some platforms require.

Signed-off-by: Kenneth Lautner <kenlautner3@gmail.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c b/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c
index 38af39f41e..15dfa3699f 100644
--- a/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c
+++ b/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c
@@ -847,6 +847,7 @@ DiskIo2ReadWriteDisk (
   DISK_IO_SUBTASK         *Subtask;

   DISK_IO2_TASK           *Task;

   EFI_TPL                 OldTpl;

+  EFI_TPL                 OldTpl1;

   BOOLEAN                 Blocking;

   BOOLEAN                 SubtaskBlocking;

   LIST_ENTRY              *SubtasksPtr;

@@ -977,7 +978,7 @@ DiskIo2ReadWriteDisk (
     }

   }

 

-  gBS->RaiseTPL (TPL_NOTIFY);

+  OldTpl1 = gBS->RaiseTPL (TPL_NOTIFY);

 

   //

   // Remove all the remaining subtasks when failure.

@@ -1012,6 +1013,7 @@ DiskIo2ReadWriteDisk (
     FreePool (Task);

   }

 

+  gBS->RestoreTPL (OldTpl1);

   gBS->RestoreTPL (OldTpl);

 

   return Status;