d9f1cac51b
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1417 X86 specific BaseLib API AsmLfence() was introduced to address the Spectre Variant 1 (CVE-2017-5753) issue. The purpose of this API is to insert barriers to stop speculative execution. However, the API is highly architecture (X86) specific, and thus should be avoided using across generic code. To address this issue, this patch will add a new BaseLib API called SpeculationBarrier(). Different architectures will have different implementations for this API. For IA32 and x64, the implementation of SpeculationBarrier() will directly call AsmLfence(). For ARM and AARCH64, this patch will add a temporary empty implementation as a placeholder. We hope experts in ARM can help to contribute the actual implementation. For EBC, similar to the ARM and AARCH64 cases, a temporary empty implementation is added. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Michael D Kinney <michael.d.kinney@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Hao Wu <hao.a.wu@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>
33 lines
850 B
C
33 lines
850 B
C
/** @file
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SpeculationBarrier() function for IA32 and x64.
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Copyright (C) 2018, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials are licensed and made available
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under the terms and conditions of the BSD License which accompanies this
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distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php.
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
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WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#include <Library/BaseLib.h>
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/**
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Uses as a barrier to stop speculative execution.
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Ensures that no later instruction will execute speculatively, until all prior
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instructions have completed.
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**/
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VOID
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EFIAPI
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SpeculationBarrier (
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VOID
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)
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{
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AsmLfence ();
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}
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