Files
system76-edk2/MdeModulePkg/Universal/Variable/RuntimeDxe/SpeculationBarrierDxe.c
Hao Wu 49395ea0bc MdeModulePkg/Variable: Update to consume SpeculationBarrier
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1417

Since BaseLib API AsmLfence() is a x86 arch specific API and should be
avoided using in generic codes, this commit replaces the usage of
AsmLfence() with arch-generic API SpeculationBarrier().

Please note that speculation execution barriers are intended to be
asserted for SMM codes, hence, this commit still preserve an empty
implementation of the speculation execution barrier for the DXE codes.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
2018-12-25 09:16:11 +08:00

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C

/** @file
Barrier to stop speculative execution (DXE version).
Copyright (c) 2018, 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.
**/
#include "Variable.h"
/**
This service is consumed by the variable modules to place a barrier to stop
speculative execution.
Ensures that no later instruction will execute speculatively, until all prior
instructions have completed.
**/
VOID
VariableSpeculationBarrier (
VOID
)
{
//
// Do nothing.
//
}