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MdeModulePkg/Variable/RuntimeDxe: move SecureBootHook() decl to new header

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If the platform supports SMM, a gRT->SetVariable() call at boot time
results in the following call tree to SecureBootHook():

  RuntimeServiceSetVariable()      [VariableSmmRuntimeDxe.c, unprivileged]
    SmmVariableHandler()           [VariableSmm.c,             PRIVILEGED]
      VariableServiceSetVariable() [Variable.c,                PRIVILEGED]
        SecureBootHook()           [VariableSmm.c,             PRIVILEGED]
          //
          // do nothing
          //
    SecureBootHook()               [Measurement.c,           unprivileged]
      //
      // measure variable if it
      // is related to SB policy
      //

And if the platform does not support SMM:

  VariableServiceSetVariable()     [Variable.c,              unprivileged]
    SecureBootHook()               [Measurement.c,           unprivileged]
      //
      // measure variable if it
      // is related to SB policy
      //

In other words, the measurement always happens outside of SMM.

Because there are two implementations of the SecureBootHook() API, one
that is called from SMM and does nothing, and another that is called
outside of SMM and measures variables, the function declaration should be
in a header file. This way the compiler can enforce that the function
declaration and all function definitions match.

"Variable.h" is used for "including common header files, defining internal
structures and functions used by Variable modules". Technically, we could
declare SecureBootHook() in "Variable.h". However, "Measurement.c" and
"VariableSmmRuntimeDxe.c" themselves do not include "Variable.h", and that
is likely intentional -- "Variable.h" exposes so much of the privileged
variable implementation that it is likely excluded from these C source
files on purpose.

Therefore introduce a new header file called "PrivilegePolymorphic.h".
"Variable.h" includes this header (so that all C source files that have
been allowed to see the variable internals learn about the new
SecureBootHook() declaration immediately). In "Measurement.c" and
"VariableSmmRuntimeDxe.c", include *only* the new header.

This change cleans up commit fa0737a839d0 ("MdeModulePkg Variable: Merge
from Auth Variable driver in SecurityPkg", 2015-07-01).

Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ladi Prosek <lprosek@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Tested-by: Ladi Prosek <lprosek@redhat.com>
This commit is contained in:
Laszlo Ersek 2017-09-30 13:40:32 +02:00
parent 35ac962b54
commit 00663d047f
8 changed files with 47 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
MdeModulePkg/Universal/Variable/RuntimeDxe/Measurement.c
View File

@ -24,6 +24,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#include <Library/BaseLib.h>
#include <Library/TpmMeasurementLib.h>
#include "PrivilegePolymorphic.h"
typedef struct {
CHAR16 *VariableName;
EFI_GUID *VendorGuid;

38
MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h Normal file
View File

@ -0,0 +1,38 @@
/** @file
Polymorphic functions that are called from both the privileged driver (i.e.,
the DXE_SMM variable module) and the non-privileged drivers (i.e., one or
both of the DXE_RUNTIME variable modules).
Each of these functions has two implementations, appropriate for privileged
vs. non-privileged driver code.
Copyright (c) 2017, Red Hat, Inc.<BR>
Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available
under the terms and conditions of the BSD License which accompanies this
distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#ifndef _PRIVILEGE_POLYMORPHIC_H_
#define _PRIVILEGE_POLYMORPHIC_H_
#include <Uefi/UefiBaseType.h>
/**
SecureBoot Hook for auth variable update.
@param[in] VariableName Name of Variable to be found.
@param[in] VendorGuid Variable vendor GUID.
**/
VOID
EFIAPI
SecureBootHook (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid
);
#endif

14
MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
View File

@ -97,20 +97,6 @@ AUTH_VAR_LIB_CONTEXT_IN mAuthContextIn = {
AUTH_VAR_LIB_CONTEXT_OUT mAuthContextOut;
/**
SecureBoot Hook for auth variable update.
@param[in] VariableName Name of Variable to be found.
@param[in] VendorGuid Variable vendor GUID.
**/
VOID
EFIAPI
SecureBootHook (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid
);
/**
Initialization for MOR Lock Control.

2
MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h
View File

@ -44,6 +44,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#include <Guid/FaultTolerantWrite.h>
#include <Guid/VarErrorFlag.h>
#include "PrivilegePolymorphic.h"
#define EFI_VARIABLE_ATTRIBUTES_MASK (EFI_VARIABLE_NON_VOLATILE | \
EFI_VARIABLE_BOOTSERVICE_ACCESS | \
EFI_VARIABLE_RUNTIME_ACCESS | \

1
MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
View File

@ -41,6 +41,7 @@
Variable.c
VariableDxe.c
Variable.h
PrivilegePolymorphic.h
Measurement.c
TcgMorLockDxe.c
VarCheck.c

1
MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
View File

@ -51,6 +51,7 @@
VariableSmm.c
VarCheck.c
Variable.h
PrivilegePolymorphic.h
VariableExLib.c
TcgMorLockSmm.c

16
MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
View File

@ -44,6 +44,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#include <Guid/EventGroup.h>
#include <Guid/SmmVariableCommon.h>
#include "PrivilegePolymorphic.h"
EFI_HANDLE mHandle = NULL;
EFI_SMM_VARIABLE_PROTOCOL *mSmmVariable = NULL;
EFI_EVENT mVirtualAddressChangeEvent = NULL;
@ -56,20 +58,6 @@ EFI_LOCK mVariableServicesLock;
EDKII_VARIABLE_LOCK_PROTOCOL mVariableLock;
EDKII_VAR_CHECK_PROTOCOL mVarCheck;
/**
SecureBoot Hook for SetVariable.
@param[in] VariableName Name of Variable to be found.
@param[in] VendorGuid Variable vendor GUID.
**/
VOID
EFIAPI
SecureBootHook (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid
);
/**
Some Secure Boot Policy Variable may update following other variable changes(SecureBoot follows PK change, etc).
Record their initial State when variable write service is ready.

1
MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.inf
View File

@ -42,6 +42,7 @@
[Sources]
VariableSmmRuntimeDxe.c
PrivilegePolymorphic.h
Measurement.c
[Packages]