Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752208AbeACL5s (ORCPT + 1 other); Wed, 3 Jan 2018 06:57:48 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:39194 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145AbeACL5r (ORCPT ); Wed, 3 Jan 2018 06:57:47 -0500 Date: Wed, 3 Jan 2018 12:57:45 +0100 (CET) From: Thomas Gleixner To: Lars Wendler cc: LKML , x86@kernel.org, Borislav Betkov , Andy Lutomirski , Dave Hansen , Peter Zijlstra , Greg KH Subject: Re: CONFIG_PAGE_TABLE_ISOLATION=y on x86_64 causes gcc to segfault when building x86_32 binaries In-Reply-To: <20180103123723.1dd26828@abudhabi.paradoxon.rec> Message-ID: References: <20180103123723.1dd26828@abudhabi.paradoxon.rec> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Lars, On Wed, 3 Jan 2018, Lars Wendler wrote: Thanks for the report. > I already had a conversation with Thomas Gleixner about this issue and > he asked me to post it here. > > After upgrading my system to vanilla 4.14.11 kernel with > CONFIG_PAGE_TABLE_ISOLATION=y I could no longer build any 32bit > binaries because gcc (7.2.0) segfaults. That's a 64bit binary, right? > This only happens with CONFIG_PAGE_TABLE_ISOLATION=y > I can get rid of this issue by setting CONFIG_PAGE_TABLE_ISOLATION=n > _or_ adding pti=off to the kernel command line (the latter was > suggested by Thomas). > > Please find attached the kernel's config together with the dmesg output > of the kernel that produces segfaults and the one with pti=off. I also > attached a config.log file from a build where gcc segfaulted. > > If you need more information, please don't hesitate to ask. will do. Thanks, tglx