From: Amit Kumar <amit.ak@samsung.com>
Date: Fri, 23 Jun 2017 10:09:47 +0000 (+0800)
Subject: MdeModulePkg/DxeCore: Fixed Interface returned by CoreOpenProtocol
X-Git-Tag: edk2-stable201903~3359
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=89f7f2cdf0266619976cb53b45b5de1aba2f8fac

MdeModulePkg/DxeCore: Fixed Interface returned by CoreOpenProtocol

Change since v4: Revise the patch based on V4 sent by Amit Kumar
1) Only return the corresponding protocol interface in *Interface
if the return status is EFI_SUCCESS or EFI_ALREADY_STARTED.
2) Interface is returned unmodified for all error conditions except
EFI_UNSUPPORTED and EFI_ALREADY_STARTED, NULL will be returned in
*Interface when EFI_UNSUPPORTED and Attributes is not
EFI_OPEN_PROTOCOL_TEST_PROTOCOL, the protocol interface will be
returned in *Interface when EFI_ALREADY_STARTED.

Change since v3:
1) Fixed issue when Attributes = EFI_OPEN_PROTOCOL_TEST_PROTOCOL
and Inteface = NULL case. [Reported by:star.zeng at intel.com]

Change Since v2:
1) Modified to use EFI_ERROR to get status code

Change since v1:
1) Fixed typo protocal to protocol
2) Fixed coding style

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Amit Kumar <amit.ak@samsung.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Gabriel Somlo <gsomlo@gmail.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Amit Kumar <amit.ak@samsung.com>
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Gabriel Somlo <gsomlo@gmail.com>
---

diff --git a/MdeModulePkg/Core/Dxe/Hand/Handle.c b/MdeModulePkg/Core/Dxe/Hand/Handle.c
index 9b2809dbe5..3ed187b279 100644
--- a/MdeModulePkg/Core/Dxe/Hand/Handle.c
+++ b/MdeModulePkg/Core/Dxe/Hand/Handle.c
@@ -1004,12 +1004,8 @@ CoreOpenProtocol (
   //
   // Check for invalid Interface
   //
-  if (Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
-    if (Interface == NULL) {
-      return EFI_INVALID_PARAMETER;
-    } else {
-      *Interface = NULL;
-    }
+  if ((Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) && (Interface == NULL)) {
+    return EFI_INVALID_PARAMETER;
   }
 
   //
@@ -1076,12 +1072,6 @@ CoreOpenProtocol (
     goto Done;
   }
 
-  //
-  // This is the protocol interface entry for this protocol
-  //
-  if (Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
-    *Interface = Prot->Interface;
-  }
   Status = EFI_SUCCESS;
 
   ByDriver        = FALSE;
@@ -1177,8 +1167,28 @@ CoreOpenProtocol (
   }
 
 Done:
+
+  if (Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
+    //
+    // Keep Interface unmodified in case of any Error
+    // except EFI_ALREADY_STARTED and EFI_UNSUPPORTED.
+    //
+    if (!EFI_ERROR (Status) || Status == EFI_ALREADY_STARTED) {
+      //
+      // EFI_ALREADY_STARTED is not an error for bus driver.
+      // Return the corresponding protocol interface.
+      //
+      *Interface = Prot->Interface;
+    } else if (Status == EFI_UNSUPPORTED) {
+      //
+      // Return NULL Interface if Unsupported Protocol.
+      //
+      *Interface = NULL;
+    }
+  }
+
   //
-  // Done. Release the database lock are return
+  // Done. Release the database lock and return
   //
   CoreReleaseProtocolLock ();
   return Status;