Re: [PATCH V3] MdeModulePkg/DxeCore: Fixed Interface returned by CoreOpenProtocol

["Zeng, Star" <star.zeng@intel.com>]

Amit,

If consumer calls OpenProtocol with Attributes = EFI_OPEN_PROTOCOL_TEST_PROTOCOL and Interface = NULL, and the protocol could not be found, how could the code with the patch work to assign *Interface = NULL?

And also UEFI spec has words Interface will be ignored if Attributes is EFI_OPEN_PROTOCOL_TEST_PROTOCOL.
“InterfaceSupplies the address where a pointer to the corresponding Protocol Interface is returned. NULL will be returned in *Interface if a structure is not associated with Protocol. This parameter is optional, and will be ignored if Attributes is EFI_OPEN_PROTOCOL_TEST_PROTOCOL.”

Thanks,
Star
From: Amit Kumar [mailto:amit.ak@samsung.com]
Sent: Thursday, June 22, 2017 8:54 PM
To: edk2-devel@lists.01.org; Gao, Liming <liming.gao@intel.com>; Zeng, Star <star.zeng@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Tian, Feng <feng.tian@intel.com>
Subject: RE: RE: [edk2] [PATCH V3] MdeModulePkg/DxeCore: Fixed Interface returned by CoreOpenProtocol


>>Should the code
>>
>>+    // Return NULL Interface if Unsupported Protocol
>>+    *Interface = NULL;
>>
>>be
>>
>>+    if (Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {
>>+      // Return NULL Interface if Unsupported Protocol
>>+      *Interface = NULL;
>>+    }
>>
>>to cover the case Attributes = EFI_OPEN_PROTOCOL_TEST_PROTOCOL and Interface = NULL?
>>
>>
>>Thanks,
>>Star



Hello Star,



It looks like and you suggestion is apt and satisfies the use case scenarios of EFI_OPEN_PROTOCOL_TEST_PROTOCOL.

But if we talk of UEFI Spec 2.7, I think the patch is good enough .

I would like to have some suggestion here from all the concerned people, if agreed I would add these changes to the patch.



Thanks And Regards

Amit





--------- Original Message ---------

Sender : Zeng, Star <star.zeng@intel.com<mailto:star.zeng@intel.com>>

Date : 2017-06-20 15:28 (GMT+5:30)

Title : RE: [edk2] [PATCH V3] MdeModulePkg/DxeCore: Fixed Interface returned by CoreOpenProtocol

To : Amit Kumar<amit.ak@samsung.com<mailto:amit.ak@samsung.com>>, null<edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>>

CC : null<liming.gao@intel.com<mailto:liming.gao@intel.com>>, null<star.zeng@intel.com<mailto:star.zeng@intel.com>>



Should the code



+    // Return NULL Interface if Unsupported Protocol

+    *Interface = NULL;



be



+    if (Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {

+      // Return NULL Interface if Unsupported Protocol

+      *Interface = NULL;

+    }



to cover the case Attributes = EFI_OPEN_PROTOCOL_TEST_PROTOCOL and Interface = NULL?





Thanks,

Star

-----Original Message-----

From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Amit Kumar

Sent: Monday, June 19, 2017 8:24 PM

To: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>

Cc: Tian, Feng <feng.tian@intel.com<mailto:feng.tian@intel.com>>

Subject: [edk2] [PATCH V3] MdeModulePkg/DxeCore: Fixed Interface returned by CoreOpenProtocol



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



Modified source code to update Interface as per spec.

1) In case of Protocol is un-supported, interface should be returned NULL.

2) In case of any error, interface should not be modified.

3) In case of Test Protocol, interface is optional.



Contributed-under: TianoCore Contribution Agreement 1.0

Signed-off-by: Amit Kumar <amit.ak@samsung.com<mailto:amit.ak@samsung.com>>

---

 MdeModulePkg/Core/Dxe/Hand/Handle.c | 24 ++++++++++++------------

 1 file changed, 12 insertions(+), 12 deletions(-)



diff --git a/MdeModulePkg/Core/Dxe/Hand/Handle.c b/MdeModulePkg/Core/Dxe/Hand/Handle.c

index 1c25521..6de300f 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;

   }



   //

@@ -1073,15 +1069,11 @@ CoreOpenProtocol (

   Prot = CoreGetProtocolInterface (UserHandle, Protocol);

   if (Prot == NULL) {

     Status = EFI_UNSUPPORTED;

+    // Return NULL Interface if Unsupported Protocol

+    *Interface = NULL;

     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;

@@ -1175,6 +1167,14 @@ CoreOpenProtocol (

   }



 Done:

+

+  //

+  // This is the protocol interface entry for this protocol.

+  // In case of any Error, Interface should not be updated as per spec.

+  //

+  if (!EFI_ERROR (Status) && Attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) {

+    *Interface = Prot->Interface;

+  }

   //

   // Done. Release the database lock are return

   //

--

1.9.1



_______________________________________________

edk2-devel mailing list

edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>

https://lists.01.org/mailman/listinfo/edk2-devel



[cid:image001.png@01D2EB9B.0901B210]

[http://ext.samsung.net/mail/ext/v1/external/status/update?userid=amit.ak&do=bWFpbElEPTIwMTcwNjIyMTI1NDE5ZXBjbXM1cDM4NDkyNjBiOGMyNmYyMzM1MjJlMTYwYzlhMzQ2OTMzZSZyZWNpcGllbnRBZGRyZXNzPXN0YXIuemVuZ0BpbnRlbC5jb20_]