From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 12C9F6B0278 for ; Wed, 20 Dec 2017 16:59:30 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id n126so3037881wma.7 for ; Wed, 20 Dec 2017 13:59:30 -0800 (PST) Received: from Galois.linutronix.de (Galois.linutronix.de. [2a01:7a0:2:106d:700::1]) by mx.google.com with ESMTPS id s2si14655266wrs.115.2017.12.20.13.59.28 for (version=TLS1_2 cipher=AES128-SHA bits=128/128); Wed, 20 Dec 2017 13:59:29 -0800 (PST) Message-Id: <20171220215444.718688274@linutronix.de> Date: Wed, 20 Dec 2017 22:35:53 +0100 From: Thomas Gleixner Subject: [patch V181 50/54] x86/mm/pti: Add Kconfig References: <20171220213503.672610178@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0056-x86-mm-pti-Add-Kconfig.patch Sender: owner-linux-mm@kvack.org List-ID: To: LKML Cc: x86@kernel.org, Linus Torvalds , Andy Lutomirsky , Peter Zijlstra , Dave Hansen , Borislav Petkov , Greg KH , keescook@google.com, hughd@google.com, Brian Gerst , Josh Poimboeuf , Denys Vlasenko , Rik van Riel , Boris Ostrovsky , Juergen Gross , David Laight , Eduardo Valentin , aliguori@amazon.com, Will Deacon , Vlastimil Babka , daniel.gruss@iaik.tugraz.at, Dave Hansen , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-mm@kvack.org From: Dave Hansen Finally allow CONFIG_PAGE_TABLE_ISOLATION to be enabled. PARAVIRT generally requires that the kernel not manage its own page tables. It also means that the hypervisor and kernel must agree wholeheartedly about what format the page tables are in and what they contain. PAGE_TABLE_ISOLATION, unfortunately, changes the rules and they can not be used together. I've seen conflicting feedback from maintainers lately about whether they want the Kconfig magic to go first or last in a patch series. It's going last here because the partially-applied series leads to kernels that can not boot in a bunch of cases. I did a run through the entire series with CONFIG_PAGE_TABLE_ISOLATION=y to look for build errors, though. [ tglx: Removed SMP and !PARAVIRT dependencies as they not longer exist ] Signed-off-by: Dave Hansen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org --- security/Kconfig | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/security/Kconfig +++ b/security/Kconfig @@ -54,6 +54,16 @@ config SECURITY_NETWORK implement socket and networking access controls. If you are unsure how to answer this question, answer N. +config PAGE_TABLE_ISOLATION + bool "Remove the kernel mapping in user mode" + depends on X86_64 && !UML + help + This feature reduces the number of hardware side channels by + ensuring that the majority of kernel addresses are not mapped + into userspace. + + See Documentation/x86/pagetable-isolation.txt for more details. + config SECURITY_INFINIBAND bool "Infiniband Security Hooks" depends on SECURITY && INFINIBAND -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org