From f62ad322695d16178db464dc062fe0af592c6780 Mon Sep 17 00:00:00 2001 From: Dimitris Papastamos Date: Thu, 30 Nov 2017 14:53:53 +0000 Subject: Workaround for CVE-2017-5715 on Cortex A57 and A72 Invalidate the Branch Target Buffer (BTB) on entry to EL3 by disabling and enabling the MMU. To achieve this without performing any branch instruction, a per-cpu vbar is installed which executes the workaround and then branches off to the corresponding vector entry in the main vector table. A side effect of this change is that the main vbar is configured before any reset handling. This is to allow the per-cpu reset function to override the vbar setting. This workaround is enabled by default on the affected CPUs. Change-Id: I97788d38463a5840a410e3cea85ed297a1678265 Signed-off-by: Dimitris Papastamos --- docs/cpu-specific-build-macros.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'docs/cpu-specific-build-macros.rst') diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst index f74b4593..014817d3 100644 --- a/docs/cpu-specific-build-macros.rst +++ b/docs/cpu-specific-build-macros.rst @@ -11,6 +11,15 @@ This document describes the various build options present in the CPU specific operations framework to enable errata workarounds and to enable optimizations for a specific CPU on a platform. +Security Vulnerability Workarounds +---------------------------------- + +ARM Trusted Firmware exports a series of build flags which control which +security vulnerability workarounds should be applied at runtime. + +- ``WORKAROUND_CVE_2017_5715``: Enables the security workaround for + `CVE-2017-5715`_. Defaults to 1. + CPU Errata Workarounds ---------------------- @@ -142,6 +151,7 @@ architecture that can be enabled by the platform as desired. *Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.* +.. _CVE-2017-5715: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=2017-5715 .. _Cortex-A53 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm048406/Cortex_A53_MPCore_Software_Developers_Errata_Notice.pdf .. _Cortex-A57 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm049219/cortex_a57_mpcore_software_developers_errata_notice.pdf .. _Cortex-A72 MPCore Software Developers Errata Notice: http://infocenter.arm.com/help/topic/com.arm.doc.epm012079/index.html -- cgit v1.2.3