Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756442AbeAHUp3 (ORCPT + 1 other); Mon, 8 Jan 2018 15:45:29 -0500 Received: from terminus.zytor.com ([65.50.211.136]:46327 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755739AbeAHUp2 (ORCPT ); Mon, 8 Jan 2018 15:45:28 -0500 Date: Mon, 8 Jan 2018 12:42:41 -0800 From: tip-bot for Dave Hansen Message-ID: Cc: hpa@zytor.com, law@redhat.com, jcm@redhat.com, tim.c.chen@linux.intel.com, aarcange@redhat.com, dwmw@amazon.co.uk, gnomes@lxorguk.ukuu.org.uk, pbonzini@redhat.com, dave.hansen@linux.intel.com, torvalds@linux-foundation.org, nickc@redhat.com, andi@firstfloor.org, tglx@linutronix.de, dave.hansen@intel.com, gregkh@linux-foundation.org, mingo@kernel.org, linux-kernel@vger.kernel.org Reply-To: pbonzini@redhat.com, dave.hansen@linux.intel.com, dwmw@amazon.co.uk, gnomes@lxorguk.ukuu.org.uk, jcm@redhat.com, tim.c.chen@linux.intel.com, aarcange@redhat.com, hpa@zytor.com, law@redhat.com, gregkh@linux-foundation.org, mingo@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, dave.hansen@intel.com, nickc@redhat.com, torvalds@linux-foundation.org, andi@firstfloor.org In-Reply-To: <20180108102805.GK25546@redhat.com> References: <20180108102805.GK25546@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/pti] x86/tboot: Unbreak tboot with PTI enabled Git-Commit-ID: 262b6b30087246abf09d6275eb0c0dc421bcbe38 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Commit-ID: 262b6b30087246abf09d6275eb0c0dc421bcbe38 Gitweb: https://git.kernel.org/tip/262b6b30087246abf09d6275eb0c0dc421bcbe38 Author: Dave Hansen AuthorDate: Sat, 6 Jan 2018 18:41:14 +0100 Committer: Thomas Gleixner CommitDate: Mon, 8 Jan 2018 17:29:18 +0100 x86/tboot: Unbreak tboot with PTI enabled This is another case similar to what EFI does: create a new set of page tables, map some code at a low address, and jump to it. PTI mistakes this low address for userspace and mistakenly marks it non-executable in an effort to make it unusable for userspace. Undo the poison to allow execution. Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig") Signed-off-by: Dave Hansen Signed-off-by: Andrea Arcangeli Signed-off-by: Thomas Gleixner Cc: Alan Cox Cc: Tim Chen Cc: Jon Masters Cc: Dave Hansen Cc: Andi Kleen Cc: Jeff Law Cc: Paolo Bonzini Cc: Linus Torvalds Cc: Greg Kroah-Hartman Cc: David" Cc: Nick Clifton Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180108102805.GK25546@redhat.com --- arch/x86/kernel/tboot.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index a4eb279..75869a4 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -127,6 +127,7 @@ static int map_tboot_page(unsigned long vaddr, unsigned long pfn, p4d = p4d_alloc(&tboot_mm, pgd, vaddr); if (!p4d) return -1; + pgd->pgd &= ~_PAGE_NX; pud = pud_alloc(&tboot_mm, p4d, vaddr); if (!pud) return -1;