[PATCH] ArmPlatformPkg/PlatformIntelBdsLib: don't clobber ConSplitter handle

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

The InitializeConsolePipe() routine takes care to only set its output
argument *Interface if it is not already set, to prevent overwriting
the ConSplitter interface pointer that may have already been assigned.

However, the associated OUT argument 'Handle' is clobbered by the
subsequent unnecessary LocateDevicePath() invocation, which should
similarly be made dependent on whether *Interface has been set
already.

Reported-by: "Lee, Terry Ping-Chung" <terry.lee@hpe.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---

Terry: does this work for you? Thanks.

 ArmPlatformPkg/Library/PlatformIntelBdsLib/IntelBdsPlatform.c | 25 ++++++++++----------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/ArmPlatformPkg/Library/PlatformIntelBdsLib/IntelBdsPlatform.c b/ArmPlatformPkg/Library/PlatformIntelBdsLib/IntelBdsPlatform.c
index 885866854329..f8e04efea63d 100644
--- a/ArmPlatformPkg/Library/PlatformIntelBdsLib/IntelBdsPlatform.c
+++ b/ArmPlatformPkg/Library/PlatformIntelBdsLib/IntelBdsPlatform.c
@@ -148,12 +148,19 @@ InitializeConsolePipe (
 
     Status = BdsLibConnectDevicePath (DevicePath);
     if (!EFI_ERROR (Status)) {
-      //
-      // If BdsLibConnectDevicePath () succeeded, *Handle must have a non-NULL
-      // value. So ASSERT that this is the case.
-      //
-      gBS->LocateDevicePath (&gEfiDevicePathProtocolGuid, &DevicePath, Handle);
-      ASSERT (*Handle != NULL);
+
+      // If the console splitter driver is not supported by the platform then
+      // use the first Device Path instance for the console interface.
+      if (*Interface == NULL) {
+        //
+        // If BdsLibConnectDevicePath () succeeded, *Handle must have a non-NULL
+        // value. So ASSERT that this is the case.
+        //
+        gBS->LocateDevicePath (&gEfiDevicePathProtocolGuid, &DevicePath, Handle);
+        ASSERT (*Handle != NULL);
+
+        gBS->HandleProtocol (*Handle, Protocol, Interface);
+      }
     }
     DEBUG_CODE_BEGIN();
       if (EFI_ERROR(Status)) {
@@ -172,12 +179,6 @@ InitializeConsolePipe (
         }
       }
     DEBUG_CODE_END();
-
-    // If the console splitter driver is not supported by the platform then use the first Device Path
-    // instance for the console interface.
-    if (!EFI_ERROR(Status) && (*Interface == NULL)) {
-      Status = gBS->HandleProtocol (*Handle, Protocol, Interface);
-    }
   }
 
   // No Device Path has been defined for this console interface. We take the first protocol implementation
-- 
2.7.4