Re: [PATCH] UserAuthFeaturePkg/UserAuthenticationDxeSmm: The SMI to handle the user authentication should be unregister before booting to OS

["Dandan Bi" <dandan.bi@intel.com>]

Hi Hao,


Some minor comments below. Please check inline.



Thanks,
Dandan

> -----Original Message-----
> From: Shi, Hao <hao.shi@intel.com>
> Sent: Thursday, September 23, 2021 12:02 PM
> To: devel@edk2.groups.io
> Cc: Shi, Hao <hao.shi@intel.com>; Bi, Dandan <dandan.bi@intel.com>
> Subject: [PATCH] UserAuthFeaturePkg/UserAuthenticationDxeSmm: The
> SMI to handle the user authentication should be unregister before booting
> to OS
> 
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3648
> 
> Register SmmExitBootServices and SmmLegacyBoot callback function to
> unregister this handler.
> 
> Signed-off-by: Hao Shi <hao.shi@intel.com>
> 
> ---
>  .../UserAuthenticationSmm.c                   | 34 +++++++++++++++++++
>  .../UserAuthenticationSmm.inf                 |  2 ++
>  2 files changed, 36 insertions(+)
> 
> diff --git
> a/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthenticationDx
> eSmm/UserAuthenticationSmm.c
> b/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthenticationDx
> eSmm/UserAuthenticationSmm.c
> index 07e834eb..30f889dd 100644
> ---
> a/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthenticationDx
> eSmm/UserAuthenticationSmm.c
> +++
> b/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthentication
> +++ DxeSmm/UserAuthenticationSmm.c
> @@ -13,6 +13,7 @@ UINTN                           mAdminPasswordTryCount = 0;
> 
>  BOOLEAN                         mNeedReVerify = TRUE;
>  BOOLEAN                         mPasswordVerified = FALSE;
> +EFI_HANDLE                      mSmmHandle = NULL;
> 
>  /**
>    Verify if the password is correct.
> @@ -612,6 +613,30 @@ EXIT:
>    return EFI_SUCCESS;
>  }
> 
> +/**
> +  Performs Exit Boot Services UserAuthentication actions
> +
> +  @param[in] Protocol   Points to the protocol's unique identifier.
> +  @param[in] Interface  Points to the interface instance.
> +  @param[in] Handle     The handle on which the interface was installed.
> +
> +  @retval EFI_SUCCESS   Notification runs successfully.
> +**/
> +EFI_STATUS
> +EFIAPI
> +UaExitBootServices (
> +  IN CONST EFI_GUID     *Protocol,
> +  IN VOID               *Interface,
> +  IN EFI_HANDLE         Handle
> +  )
> +{
> +  DEBUG ((DEBUG_INFO, "Unregister User Authentication Smi\n"));
> +
> +  gSmst->SmiHandlerUnRegister(mSmmHandle);
> +
> +  return EFI_SUCCESS;
> +}
> +
>  /**
>    Main entry for this driver.
> 
> @@ -633,6 +658,7 @@ PasswordSmmInit (
>    EDKII_VARIABLE_LOCK_PROTOCOL          *VariableLock;
>    CHAR16
> PasswordHistoryName[sizeof(USER_AUTHENTICATION_VAR_NAME)/sizeof(
> CHAR16) + 5];
>    UINTN                                 Index;
> +  EFI_EVENT                           ExitBootServicesEvent;
Please take care the alignment between new added code and old ones.

> 
>    ASSERT (PASSWORD_HASH_SIZE == SHA256_DIGEST_SIZE);
>    ASSERT (PASSWORD_HISTORY_CHECK_COUNT < 0xFFFF); @@ -663,6
> +689,14 @@ PasswordSmmInit (
>    if (EFI_ERROR (Status)) {
>      return Status;
>    }
> +  mSmmHandle = SmmHandle;
Could we only use one global variable for register and unregister? Then can remove this statement.

> +  //
> +  // Register for SmmExitBootServices and SmmLegacyBoot notification.
> +  //
> +  Status = gSmst->SmmRegisterProtocolNotify
> + (&gEdkiiSmmExitBootServicesProtocolGuid, UaExitBootServices,
> + &ExitBootServicesEvent);  ASSERT_EFI_ERROR (Status);  Status =
> + gSmst->SmmRegisterProtocolNotify (&gEdkiiSmmLegacyBootProtocolGuid,
> + UaExitBootServices, &ExitBootServicesEvent);  ASSERT_EFI_ERROR
> + (Status);

Could we not use &ExitBootServicesEvent for these two RegisterProtocolNotify? One generic name for both or two specific names for each?

> 
>    if (IsPasswordCleared()) {
>      DEBUG ((DEBUG_INFO, "IsPasswordCleared\n")); diff --git
> a/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthenticationDx
> eSmm/UserAuthenticationSmm.inf
> b/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthenticationDx
> eSmm/UserAuthenticationSmm.inf
> index 0b33b194..d73a2fe2 100644
> ---
> a/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthenticationDx
> eSmm/UserAuthenticationSmm.inf
> +++
> b/Features/Intel/UserInterface/UserAuthFeaturePkg/UserAuthentication
> +++ DxeSmm/UserAuthenticationSmm.inf
> @@ -48,6 +48,8 @@
>  [Protocols]
>    gEdkiiVariableLockProtocolGuid                ## CONSUMES
>    gEfiSmmVariableProtocolGuid                   ## CONSUMES
> +  gEdkiiSmmExitBootServicesProtocolGuid         ## CONSUMES
> +  gEdkiiSmmLegacyBootProtocolGuid               ## CONSUMES
> 
>  [Depex]
>    gEfiSmmVariableProtocolGuid AND gEfiVariableWriteArchProtocolGuid
> --
> 2.26.2.windows.1