Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751734AbeADAh5 (ORCPT + 1 other); Wed, 3 Jan 2018 19:37:57 -0500 Received: from mail-pl0-f48.google.com ([209.85.160.48]:46745 "EHLO mail-pl0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751066AbeADAhz (ORCPT ); Wed, 3 Jan 2018 19:37:55 -0500 X-Google-Smtp-Source: ACJfBotKRKpKHVP0bFSC2E34Ypqx96XDNpeG7SphU5QyRUwdmZk3Hf+bbOT9YxDFHPEIk0mXLtMN5w== Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (1.0) Subject: Re: "bad pmd" errors + oops with KPTI on 4.14.11 after loading X.509 certs From: Andy Lutomirski X-Mailer: iPhone Mail (15C153) In-Reply-To: <20180104003303.GA1654@trogon.sfo.coreos.systems> Date: Wed, 3 Jan 2018 16:37:53 -0800 Cc: Greg Kroah-Hartman , x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Andy Lutomirski , Dave Hansen , Peter Zijlstra Content-Transfer-Encoding: 8BIT Message-Id: References: <20180103084600.GA31648@trogon.sfo.coreos.systems> <20180103092016.GA23772@kroah.com> <20180104003303.GA1654@trogon.sfo.coreos.systems> To: Benjamin Gilbert Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: > On Jan 3, 2018, at 4:33 PM, Benjamin Gilbert wrote: > >> On Wed, Jan 03, 2018 at 10:20:16AM +0100, Greg Kroah-Hartman wrote: >> Ick, not good, any chance you can test 4.15-rc6 to verify that the issue >> is also there (or not)? > > I haven't been able to reproduce this on 4.15-rc6. Ah. Maybe try rebuilding a bad kernel with free_ldt_pgtables() modified to do nothing, and the read /sys/kernel/debug/page_tables/current (or current_kernel, or whatever it's called). The problem may be obvious. > > --Benjamin Gilbert