Re: [edk2-devel] [PATCH 09/35] MdeModulePkg: stop abusing EFI_EVENT for protocol notify registration

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 9/17/19 9:49 PM, Laszlo Ersek wrote:
> EfiCreateProtocolNotifyEvent() takes a (VOID**) for "Registration",
> similarly to gBS->RegisterProtocolNotify(). We should pass the address of
> an actual pointer-to-VOID, and not the address of an EFI_EVENT. EFI_EVENT
> just happens to be specified as (VOID*), and has nothing to do with the
> registration.
> 
> The same applies to gMmst->MmRegisterProtocolNotify().
> 
> "mFtwRegistration", "mFvRegistration", and "mFvbRegistration" are used for
> nothing else.
> 
> This change is a no-op in practice; it's a semantic improvement.
> 
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Zhichao Gao <zhichao.gao@intel.com>
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
> 
> Notes:
>     lightly tested, as these modules (except LoadFileOnFv2) are part of the
>     ArmVirt and/or OVMF platforms
> 
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c | 2 +-
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c | 2 +-
>  MdeModulePkg/Universal/LoadFileOnFv2/LoadFileOnFv2.c                 | 2 +-
>  MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c             | 2 +-
>  4 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> index ae8f117905cd..de38ea028af1 100644
> --- a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> +++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> @@ -47,7 +47,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
>  
>  #include <Library/UefiBootServicesTableLib.h>
>  #include "FaultTolerantWrite.h"
> -EFI_EVENT                                 mFvbRegistration = NULL;
> +VOID                                      *mFvbRegistration = NULL;
>  
>  
>  /**
> diff --git a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> index e8e935a85b5b..9612b394865b 100644
> --- a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> +++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> @@ -56,7 +56,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
>  #include "FaultTolerantWriteSmmCommon.h"
>  #include <Protocol/MmEndOfDxe.h>
>  
> -EFI_EVENT                                 mFvbRegistration = NULL;
> +VOID                                      *mFvbRegistration = NULL;
>  EFI_FTW_DEVICE                            *mFtwDevice      = NULL;
>  
>  ///
> diff --git a/MdeModulePkg/Universal/LoadFileOnFv2/LoadFileOnFv2.c b/MdeModulePkg/Universal/LoadFileOnFv2/LoadFileOnFv2.c
> index 4af2da05e145..43fa6ce12875 100644
> --- a/MdeModulePkg/Universal/LoadFileOnFv2/LoadFileOnFv2.c
> +++ b/MdeModulePkg/Universal/LoadFileOnFv2/LoadFileOnFv2.c
> @@ -36,7 +36,7 @@ typedef struct {
>  #define LOAD_FILE_ON_FV2_PRIVATE_DATA_FROM_THIS(a) CR (a, LOAD_FILE_ON_FV2_PRIVATE_DATA, LoadFile, LOAD_FILE_ON_FV2_PRIVATE_DATA_SIGNATURE)
>  #define LOAD_FILE_ON_FV2_PRIVATE_DATA_FROM_LINK(a) CR (a, LOAD_FILE_ON_FV2_PRIVATE_DATA, Link, LOAD_FILE_ON_FV2_PRIVATE_DATA_SIGNATURE)
>  
> -EFI_EVENT  mFvRegistration;
> +VOID       *mFvRegistration;
>  LIST_ENTRY mPrivateDataList;
>  
>  /**
> diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
> index 3d232bb36cb4..7d2b6c8e1fad 100644
> --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
> +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
> @@ -13,7 +13,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
>  
>  EFI_HANDLE                          mHandle                    = NULL;
>  EFI_EVENT                           mVirtualAddressChangeEvent = NULL;
> -EFI_EVENT                           mFtwRegistration           = NULL;
> +VOID                                *mFtwRegistration          = NULL;
>  VOID                                ***mVarCheckAddressPointer = NULL;
>  UINTN                               mVarCheckAddressPointerCount = 0;
>  EDKII_VARIABLE_LOCK_PROTOCOL        mVariableLock              = { VariableLockRequestToLock };

Surprisingly the one declared in
MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c is correct :)

Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>