Re: [edk2-devel] [PATCH V2 4/9] MdeModulePkg/Variable: Add local auth status in VariableParsing

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: Kubacki, Michael A
> Sent: Friday, October 04, 2019 2:35 AM
> To: Wu, Hao A; devel@edk2.groups.io
> Cc: Bi, Dandan; Ard Biesheuvel; Dong, Eric; Laszlo Ersek; Gao, Liming; Kinney,
> Michael D; Ni, Ray; Wang, Jian J; Yao, Jiewen
> Subject: RE: [edk2-devel] [PATCH V2 4/9] MdeModulePkg/Variable: Add local
> auth status in VariableParsing
> 
> I will make the following changes in V3:
> 
> > InitVariableParsing() seems an internal function, the 'EFIAPI' keyword can
> be
> > dropped. Please help to update the function definition in .C file as well.
> 
> I will remove the EFIAPI keyword.
> 
> > > diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > index 1a57d7e1ba..53d797152c 100644
> > > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > @@ -3326,6 +3326,9 @@ InitNonVolatileVariableStore (
> > >    mVariableModuleGlobal->MaxVariableSize = PcdGet32
> > > (PcdMaxVariableSize);
> > >    mVariableModuleGlobal->MaxAuthVariableSize = ((PcdGet32
> > > (PcdMaxAuthVariableSize) != 0) ? PcdGet32 (PcdMaxAuthVariableSize) :
> > > mVariableModuleGlobal->MaxVariableSize);
> > >
> > > +  Status = InitVariableParsing (mVariableModuleGlobal-
> > > >VariableGlobal.AuthFormat);
> > > +  ASSERT_EFI_ERROR (Status);
> > > +
> >
> >
> > After the above initialization, mVariableModuleGlobal-
> > >VariableGlobal.AuthFormat
> > will be changed temporarily within
> > ConvertNormalVarStorageToAuthVarStorage() if normal HOB variable store
> > will be converted to the auth format:
> >
> > VOID *
> > ConvertNormalVarStorageToAuthVarStorage (
> >   VARIABLE_STORE_HEADER *NormalVarStorage
> >   )
> > {
> >   ...
> >   //
> >   // Set AuthFormat as FALSE for normal variable storage
> >   //
> >   mVariableModuleGlobal->VariableGlobal.AuthFormat = FALSE;
> >   ...
> >   //
> >   // Restore AuthFormat
> >   //
> >   mVariableModuleGlobal->VariableGlobal.AuthFormat = TRUE;
> >   return AuthVarStorage;
> > }
> >
> >
> > I think there will be issues in such converting, since I found that at least
> > GetVariableHeaderSize() and NameSizeOfVariable() get called during the
> > execution of ConvertNormalVarStorageToAuthVarStorage(). And they are
> > checking 'mAuthFormat' rather than 'mVariableModuleGlobal-
> > >VariableGlobal.AuthFormat'.
> >
> >
> 
> You're right that will be a problem. I missed this temporary change in the
> value.
> I'm going to have all the functions dependent on authentication status in
> VariableParsing.c take it as a parameter and let the respective drivers linked
> against it maintain their own single copy of the authentication state.


I am really sorry for not raising this question until I saw the latest patch
series:

Is it possible to call the InitVariableParsing() function (maybe a rename for
the function for better understanding) for the temporary changes for
'mVariableModuleGlobal->VariableGlobal.AuthFormat' in function
ConvertNormalVarStorageToAuthVarStorage()?

In my opinion, doing so can avoid changing many function interfaces.

Best Regards,
Hao Wu


> 
> > >    //
> > >    // Parse non-volatile variable data and get last variable offset.
> > >    //
> > > @@ -3756,18 +3759,13 @@ VariableCommonInitialize (
> > >
> > >    //
> > >    // mVariableModuleGlobal->VariableGlobal.AuthFormat
> > > -  // has been initialized in InitNonVolatileVariableStore().
> > > +  // is initialized in InitNonVolatileVariableStore().
> > >    //
> > >    if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > >      DEBUG ((EFI_D_INFO, "Variable driver will work with auth variable
> > > format!\n"));
> > > -    //
> > > -    // Set AuthSupport to FALSE first, VariableWriteServiceInitialize() will
> > > initialize it.
> > > -    //
> > > -    mVariableModuleGlobal->VariableGlobal.AuthSupport = FALSE;
> > >      VariableGuid = &gEfiAuthenticatedVariableGuid;
> > >    } else {
> > >      DEBUG ((EFI_D_INFO, "Variable driver will work without auth
> > > variable support!\n"));
> > > -    mVariableModuleGlobal->VariableGlobal.AuthSupport = FALSE;
> >
> >
> > Not sure why the above changes belong to this patch.
> > Could you help to double confirm?
> 
> This was used during testing and is not needed. I will remove it.
> 
> Thanks,
> Michael
> 
> > -----Original Message-----
> > From: Wu, Hao A <hao.a.wu@intel.com>
> > Sent: Thursday, October 3, 2019 1:04 AM
> > To: devel@edk2.groups.io; Kubacki, Michael A
> > <michael.a.kubacki@intel.com>
> > Cc: Bi, Dandan <dandan.bi@intel.com>; Ard Biesheuvel
> > <ard.biesheuvel@linaro.org>; Dong, Eric <eric.dong@intel.com>; Laszlo
> Ersek
> > <lersek@redhat.com>; Gao, Liming <liming.gao@intel.com>; Kinney,
> Michael
> > D <michael.d.kinney@intel.com>; Ni, Ray <ray.ni@intel.com>; Wang, Jian J
> > <jian.j.wang@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>
> > Subject: RE: [edk2-devel] [PATCH V2 4/9] MdeModulePkg/Variable: Add
> local
> > auth status in VariableParsing
> >
> > Inline comments below:
> >
> >
> > > -----Original Message-----
> > > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf
> Of
> > > Kubacki, Michael A
> > > Sent: Saturday, September 28, 2019 9:47 AM
> > > To: devel@edk2.groups.io
> > > Cc: Bi, Dandan; Ard Biesheuvel; Dong, Eric; Laszlo Ersek; Gao, Liming;
> > > Kinney, Michael D; Ni, Ray; Wang, Jian J; Wu, Hao A; Yao, Jiewen
> > > Subject: [edk2-devel] [PATCH V2 4/9] MdeModulePkg/Variable: Add local
> > > auth status in VariableParsing
> > >
> > > The file VariableParsing.c provides generic functionality related to
> > > parsing variable related structures and information. In order to
> > > calculate offsets for certain operations, the functions must know if
> > > authenticated variables are enabled as this increases the size of
> > > variable headers.
> > >
> > > This change removes linking against a global variable in an external
> > > file in favor of a statically scoped variable in VariableParsing.c
> > > Because this file is unaware of how the authenticated variable status
> > > is determined, the variable is set through a function interface
> > > invoked during variable driver initialization.
> > >
> > > Cc: Dandan Bi <dandan.bi@intel.com>
> > > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > > Cc: Eric Dong <eric.dong@intel.com>
> > > Cc: Laszlo Ersek <lersek@redhat.com>
> > > Cc: Liming Gao <liming.gao@intel.com>
> > > Cc: Michael D Kinney <michael.d.kinney@intel.com>
> > > Cc: Ray Ni <ray.ni@intel.com>
> > > Cc: Jian J Wang <jian.j.wang@intel.com>
> > > Cc: Hao A Wu <hao.a.wu@intel.com>
> > > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > > Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
> > > ---
> > >  MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.h | 14
> > > +++++++++
> > >  MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c        | 10
> +++---
> > >  MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.c | 33
> > > ++++++++++++++++----
> > >  3 files changed, 45 insertions(+), 12 deletions(-)
> > >
> > > diff --git
> > > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.h
> > > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.h
> > > index 6f2000f3ee..3eba590634 100644
> > > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.h
> > > +++
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.h
> > > @@ -308,4 +308,18 @@ UpdateVariableInfo (
> > >    IN OUT VARIABLE_INFO_ENTRY  **VariableInfo
> > >    );
> > >
> > > +/**
> > > +  Initializes context needed for variable parsing functions.
> > > +
> > > +  @param[in]       AuthFormat          If true then indicates authenticated
> > > variables are supported
> > > +
> > > +  @retval          EFI_SUCCESS         Initialized successfully
> > > +  @retval          Others              An error occurred during initialization
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +InitVariableParsing (
> >
> >
> > InitVariableParsing() seems an internal function, the 'EFIAPI' keyword can
> be
> > dropped. Please help to update the function definition in .C file as well.
> >
> >
> > > +  IN  BOOLEAN   AuthFormat
> > > +  );
> > > +
> > >  #endif
> > > diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > index 1a57d7e1ba..53d797152c 100644
> > > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
> > > @@ -3326,6 +3326,9 @@ InitNonVolatileVariableStore (
> > >    mVariableModuleGlobal->MaxVariableSize = PcdGet32
> > > (PcdMaxVariableSize);
> > >    mVariableModuleGlobal->MaxAuthVariableSize = ((PcdGet32
> > > (PcdMaxAuthVariableSize) != 0) ? PcdGet32 (PcdMaxAuthVariableSize) :
> > > mVariableModuleGlobal->MaxVariableSize);
> > >
> > > +  Status = InitVariableParsing (mVariableModuleGlobal-
> > > >VariableGlobal.AuthFormat);
> > > +  ASSERT_EFI_ERROR (Status);
> > > +
> >
> >
> > After the above initialization, mVariableModuleGlobal-
> > >VariableGlobal.AuthFormat
> > will be changed temporarily within
> > ConvertNormalVarStorageToAuthVarStorage() if normal HOB variable store
> > will be converted to the auth format:
> >
> > VOID *
> > ConvertNormalVarStorageToAuthVarStorage (
> >   VARIABLE_STORE_HEADER *NormalVarStorage
> >   )
> > {
> >   ...
> >   //
> >   // Set AuthFormat as FALSE for normal variable storage
> >   //
> >   mVariableModuleGlobal->VariableGlobal.AuthFormat = FALSE;
> >   ...
> >   //
> >   // Restore AuthFormat
> >   //
> >   mVariableModuleGlobal->VariableGlobal.AuthFormat = TRUE;
> >   return AuthVarStorage;
> > }
> >
> >
> > I think there will be issues in such converting, since I found that at least
> > GetVariableHeaderSize() and NameSizeOfVariable() get called during the
> > execution of ConvertNormalVarStorageToAuthVarStorage(). And they are
> > checking 'mAuthFormat' rather than 'mVariableModuleGlobal-
> > >VariableGlobal.AuthFormat'.
> >
> >
> > >    //
> > >    // Parse non-volatile variable data and get last variable offset.
> > >    //
> > > @@ -3756,18 +3759,13 @@ VariableCommonInitialize (
> > >
> > >    //
> > >    // mVariableModuleGlobal->VariableGlobal.AuthFormat
> > > -  // has been initialized in InitNonVolatileVariableStore().
> > > +  // is initialized in InitNonVolatileVariableStore().
> > >    //
> > >    if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > >      DEBUG ((EFI_D_INFO, "Variable driver will work with auth variable
> > > format!\n"));
> > > -    //
> > > -    // Set AuthSupport to FALSE first, VariableWriteServiceInitialize() will
> > > initialize it.
> > > -    //
> > > -    mVariableModuleGlobal->VariableGlobal.AuthSupport = FALSE;
> > >      VariableGuid = &gEfiAuthenticatedVariableGuid;
> > >    } else {
> > >      DEBUG ((EFI_D_INFO, "Variable driver will work without auth
> > > variable support!\n"));
> > > -    mVariableModuleGlobal->VariableGlobal.AuthSupport = FALSE;
> >
> >
> > Not sure why the above changes belong to this patch.
> > Could you help to double confirm?
> >
> > Best Regards,
> > Hao Wu
> >
> >
> > >      VariableGuid = &gEfiVariableGuid;
> > >    }
> > >
> > > diff --git
> > > a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.c
> > > b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.c
> > > index 394195342d..0a47f6d10d 100644
> > > --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.c
> > > +++
> b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.c
> > > @@ -9,6 +9,8 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> > >
> > >  #include "VariableParsing.h"
> > >
> > > +STATIC  BOOLEAN   mAuthFormat;
> > > +
> > >  /**
> > >
> > >    This code checks if variable header is valid or not.
> > > @@ -88,7 +90,7 @@ GetVariableHeaderSize (  {
> > >    UINTN Value;
> > >
> > > -  if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > > +  if (mAuthFormat) {
> > >      Value = sizeof (AUTHENTICATED_VARIABLE_HEADER);
> > >    } else {
> > >      Value = sizeof (VARIABLE_HEADER); @@ -114,7 +116,7 @@
> > > NameSizeOfVariable (
> > >    AUTHENTICATED_VARIABLE_HEADER *AuthVariable;
> > >
> > >    AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *) Variable;
> > > -  if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > > +  if (mAuthFormat) {
> > >      if (AuthVariable->State == (UINT8) (-1) ||
> > >         AuthVariable->DataSize == (UINT32) (-1) ||
> > >         AuthVariable->NameSize == (UINT32) (-1) || @@ -149,7 +151,7 @@
> > > SetNameSizeOfVariable (
> > >    AUTHENTICATED_VARIABLE_HEADER *AuthVariable;
> > >
> > >    AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *) Variable;
> > > -  if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > > +  if (mAuthFormat) {
> > >      AuthVariable->NameSize = (UINT32) NameSize;
> > >    } else {
> > >      Variable->NameSize = (UINT32) NameSize; @@ -173,7 +175,7 @@
> > > DataSizeOfVariable (
> > >    AUTHENTICATED_VARIABLE_HEADER *AuthVariable;
> > >
> > >    AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *) Variable;
> > > -  if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > > +  if (mAuthFormat) {
> > >      if (AuthVariable->State == (UINT8) (-1) ||
> > >         AuthVariable->DataSize == (UINT32) (-1) ||
> > >         AuthVariable->NameSize == (UINT32) (-1) || @@ -208,7 +210,7 @@
> > > SetDataSizeOfVariable (
> > >    AUTHENTICATED_VARIABLE_HEADER *AuthVariable;
> > >
> > >    AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *) Variable;
> > > -  if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > > +  if (mAuthFormat) {
> > >      AuthVariable->DataSize = (UINT32) DataSize;
> > >    } else {
> > >      Variable->DataSize = (UINT32) DataSize; @@ -248,7 +250,7 @@
> > > GetVendorGuidPtr (
> > >    AUTHENTICATED_VARIABLE_HEADER *AuthVariable;
> > >
> > >    AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *) Variable;
> > > -  if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
> > > +  if (mAuthFormat) {
> > >      return &AuthVariable->VendorGuid;
> > >    } else {
> > >      return &Variable->VendorGuid;
> > > @@ -746,3 +748,22 @@ UpdateVariableInfo (
> > >      }
> > >    }
> > >  }
> > > +
> > > +/**
> > > +  Initializes context needed for variable parsing functions.
> > > +
> > > +  @param[in]       AuthFormat          If true then indicates authenticated
> > > variables are supported
> > > +
> > > +  @retval          EFI_SUCCESS         Initialized successfully
> > > +  @retval          Others              An error occurred during initialization
> > > +**/
> > > +EFI_STATUS
> > > +EFIAPI
> > > +InitVariableParsing (
> > > +  IN  BOOLEAN   AuthFormat
> > > +  )
> > > +{
> > > +  mAuthFormat = AuthFormat;
> > > +
> > > +  return EFI_SUCCESS;
> > > +}
> > > --
> > > 2.16.2.windows.1
> > >
> > >
> > > 
> >
>