From c0959b4426b2da45cdb8146a5116bb4fd9b86534 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 6 Feb 2019 00:08:22 +0000 Subject: MdePkg/BaseLib: implement SpeculationBarrier() for ARM and AArch64 Replace the dummy C implementation of SpeculationBarrier() with implementations consisting of the recommended DSB SY + ISB sequence, as recommended by ARM in the whitepaper "Cache Speculation Side-channels" version 2.4, dated October 2018. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel Reviewed-by: Liming Gao Reviewed-by: Leif Lindholm --- MdePkg/Library/BaseLib/Arm/SpeculationBarrier.S | 39 +++++++++++++++++++++++ MdePkg/Library/BaseLib/Arm/SpeculationBarrier.asm | 39 +++++++++++++++++++++++ MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c | 30 ----------------- 3 files changed, 78 insertions(+), 30 deletions(-) create mode 100644 MdePkg/Library/BaseLib/Arm/SpeculationBarrier.S create mode 100644 MdePkg/Library/BaseLib/Arm/SpeculationBarrier.asm delete mode 100644 MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c (limited to 'MdePkg/Library/BaseLib/Arm') diff --git a/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.S b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.S new file mode 100644 index 0000000000..7857558aba --- /dev/null +++ b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.S @@ -0,0 +1,39 @@ +##------------------------------------------------------------------------------ +# +# SpeculationBarrier() for AArch64 +# +# Copyright (c) 2019, Linaro Ltd. All rights reserved. +# +# 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. +# +##------------------------------------------------------------------------------ + +.text +.p2align 2 + +GCC_ASM_EXPORT(SpeculationBarrier) + + +#/** +# Uses as a barrier to stop speculative execution. +# +# Ensures that no later instruction will execute speculatively, until all prior +# instructions have completed. +# +#**/ +#VOID +#EFIAPI +#SpeculationBarrier ( +# VOID +# ); +# +ASM_PFX(SpeculationBarrier): + dsb + isb + bx lr diff --git a/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.asm b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.asm new file mode 100644 index 0000000000..425cd3de9e --- /dev/null +++ b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.asm @@ -0,0 +1,39 @@ +;------------------------------------------------------------------------------ +; +; SpeculationBarrier() for AArch64 +; +; Copyright (c) 2019, Linaro Ltd. All rights reserved. +; +; 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. +; +;------------------------------------------------------------------------------ + + EXPORT SpeculationBarrier + + AREA MemoryBarriers, CODE, READONLY + +;/** +; Uses as a barrier to stop speculative execution. +; +; Ensures that no later instruction will execute speculatively, until all prior +; instructions have completed. +; +;**/ +;VOID +;EFIAPI +;SpeculationBarrier ( +; VOID +; ); +; +SpeculationBarrier + dsb + isb + bx lr + + END diff --git a/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c deleted file mode 100644 index 8a6165a102..0000000000 --- a/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c +++ /dev/null @@ -1,30 +0,0 @@ -/** @file - SpeculationBarrier() function for ARM. - - Copyright (C) 2018, Intel Corporation. All rights reserved.
- - 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. - -**/ - - -/** - Uses as a barrier to stop speculative execution. - - Ensures that no later instruction will execute speculatively, until all prior - instructions have completed. - -**/ -VOID -EFIAPI -SpeculationBarrier ( - VOID - ) -{ -} -- cgit v1.2.3