From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99123C6787C for ; Fri, 12 Oct 2018 18:10:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71B4D20645 for ; Fri, 12 Oct 2018 18:10:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 71B4D20645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727042AbeJMBn6 (ORCPT ); Fri, 12 Oct 2018 21:43:58 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:46195 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725981AbeJMBn6 (ORCPT ); Fri, 12 Oct 2018 21:43:58 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id B02C880A50; Fri, 12 Oct 2018 20:10:12 +0200 (CEST) Date: Fri, 12 Oct 2018 20:10:11 +0200 From: Pavel Machek To: Ingo Molnar , arnd@arndb.de, akpm@linux-foundation.org, luto@kernel.org, dave.hansen@linux.intel.com, jroedel@suse.de, keescook@chromium.org, torvalds@linux-foundation.org, toshi.kani@hpe.com Cc: Thomas Gleixner , sfr@canb.auug.org.au, kernel list , mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org Subject: Avoid VLA in pgd_alloc kills boot on 32-bit machines was Re: -next20181010,1011 regression: thinkpad x60 (32 bit) dies during boot. Message-ID: <20181012181011.GA9098@amd> References: <20181010195920.GA13860@amd> <20181010200331.GA13975@amd> <20181011180328.GA6740@amd> <20181012102459.GA4469@amd> <20181012105254.GA114888@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="k+w/mQv8wyuph6w0" Content-Disposition: inline In-Reply-To: <20181012105254.GA114888@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --k+w/mQv8wyuph6w0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > > So what came in between -next20181005 and the first bad one? kernel/s= ched/* > > > being the first place to look at. > >=20 > > kernel/sched does not seem to contain anything too scary. > >=20 > > I know that -next20181005 works ok, and I know -next20181010 is > > bad. Is there easy way to bisect using that information? I can do > > bisect between -next and mainline, but that's a lot of patches and > > thus not much fun :-(. > >=20 > > In the meantime, I reproduced the failure with T40p. Is there someone > > with working x86-32 in -next? >=20 > Does latest -tip fail too? If yes then I suspect bisection would be neede= d. And the winner is... [1be3f247c2882a82279cbcf43717581ea943b692] x86/mm: Avoid VLA in pgd_alloc() "Kernel stack is corrupted in: pgd_alloc" panic kind of suggests this is right commit. --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --k+w/mQv8wyuph6w0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlvA44MACgkQMOfwapXb+vIrlQCbBgdRd0mW4NBaj7ZH9F4pb8pA eLoAnjsoazRFhA3VL0aetMS7oIk16Sbj =mzvd -----END PGP SIGNATURE----- --k+w/mQv8wyuph6w0--