Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753272AbeADMNc (ORCPT + 1 other); Thu, 4 Jan 2018 07:13:32 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:40064 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753072AbeADMJv (ORCPT ); Thu, 4 Jan 2018 07:09:51 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Meelis Roos , Thomas Gleixner , Borislav Petkov , Tom Lendacky Subject: [PATCH 4.14 04/14] x86/pti: Make sure the user/kernel PTEs match Date: Thu, 4 Jan 2018 13:09:21 +0100 Message-Id: <20180104120917.613562991@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180104120917.043667757@linuxfoundation.org> References: <20180104120917.043667757@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 52994c256df36fda9a715697431cba9daecb6b11 upstream. Meelis reported that his K8 Athlon64 emits MCE warnings when PTI is enabled: [Hardware Error]: Error Addr: 0x0000ffff81e000e0 [Hardware Error]: MC1 Error: L1 TLB multimatch. [Hardware Error]: cache level: L1, tx: INSN The address is in the entry area, which is mapped into kernel _AND_ user space. That's special because we switch CR3 while we are executing there. User mapping: 0xffffffff81e00000-0xffffffff82000000 2M ro PSE GLB x pmd Kernel mapping: 0xffffffff81000000-0xffffffff82000000 16M ro PSE x pmd So the K8 is complaining that the TLB entries differ. They differ in the GLB bit. Drop the GLB bit when installing the user shared mapping. Fixes: 6dc72c3cbca0 ("x86/mm/pti: Share entry text PMD") Reported-by: Meelis Roos Signed-off-by: Thomas Gleixner Tested-by: Meelis Roos Cc: Borislav Petkov Cc: Tom Lendacky Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801031407180.1957@nanos Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pti.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -367,7 +367,8 @@ static void __init pti_setup_espfix64(vo static void __init pti_clone_entry_text(void) { pti_clone_pmds((unsigned long) __entry_text_start, - (unsigned long) __irqentry_text_end, _PAGE_RW); + (unsigned long) __irqentry_text_end, + _PAGE_RW | _PAGE_GLOBAL); } /*