2ecd829972
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1193 This commit will add a new BaseLib API AsmLfence(). This API will perform a serializing operation on all load-from-memory instructions that were issued prior to the call of this function. Please note that this API is only available on IA-32 and x64. The purpose of adding this API is to mitigate of the [CVE-2017-5753] Bounds Check Bypass issue when untrusted data are being processed within SMM. More details can be referred at the 'Bounds check bypass mitigation' section at the below link: https://software.intel.com/security-software-guidance/insights/host-firmware-speculative-execution-side-channel-mitigation Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Michael D Kinney <michael.d.kinney@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Hao Wu <hao.a.wu@intel.com> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com> Acked-by: Laszlo Ersek <lersek@redhat.com> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
38 lines
1.2 KiB
NASM
38 lines
1.2 KiB
NASM
;------------------------------------------------------------------------------ ;
|
|
; 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.
|
|
;
|
|
; Module Name:
|
|
;
|
|
; Lfence.nasm
|
|
;
|
|
; Abstract:
|
|
;
|
|
; Performs a serializing operation on all load-from-memory instructions that
|
|
; were issued prior to the call of this function.
|
|
;
|
|
; Notes:
|
|
;
|
|
;------------------------------------------------------------------------------
|
|
|
|
DEFAULT REL
|
|
SECTION .text
|
|
|
|
;------------------------------------------------------------------------------
|
|
; VOID
|
|
; EFIAPI
|
|
; AsmLfence (
|
|
; VOID
|
|
; );
|
|
;------------------------------------------------------------------------------
|
|
global ASM_PFX(AsmLfence)
|
|
ASM_PFX(AsmLfence):
|
|
lfence
|
|
ret
|