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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 17E6EC4360C for ; Wed, 16 Oct 2019 08:20:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E58D02168B for ; Wed, 16 Oct 2019 08:20:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571214029; bh=PezwXMZriBrz2Y9bP1EWUNdc1Ffp6TkPYKSmkacCBzw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZApRRndVjg/VaSdMZGKOK21N4Ed6T83OZP2dxK/I99YV9nJYZdnhJ+CIUVa/gsBf+ /CR8egyWuUUexRJb8d+2DxAT0lgT6Y3CuLVHwqJ8vhMeagda3joxSjbX3/bdRgXTxF vRJHTMmidAhC3pmrgek03sIVRoH/Asyc6Yzp7My0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391437AbfJPIU2 (ORCPT ); Wed, 16 Oct 2019 04:20:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:32772 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726949AbfJPIU2 (ORCPT ); Wed, 16 Oct 2019 04:20:28 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8F4AEBA75; Wed, 16 Oct 2019 08:20:24 +0000 (UTC) Date: Wed, 16 Oct 2019 10:20:22 +0200 From: Michal Hocko To: Anshuman Khandual Cc: Qian Cai , linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Greg Kroah-Hartman , Thomas Gleixner , Mike Rapoport , Jason Gunthorpe , Dan Williams , Peter Zijlstra , Mark Rutland , Mark Brown , Steven Price , Ard Biesheuvel , Masahiro Yamada , Kees Cook , Tetsuo Handa , Matthew Wilcox , Sri Krishna chowdary , Dave Hansen , Russell King - ARM Linux , Michael Ellerman , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , "David S. Miller" , Vineet Gupta , James Hogan , Paul Burton , Ralf Baechle , "Kirill A . Shutemov" , Gerald Schaefer , Christophe Leroy , Mike Kravetz , linux-snps-arc@lists.infradead.org, linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V6 0/2] mm/debug: Add tests validating architecture page table helpers Message-ID: <20191016082022.GN317@dhcp22.suse.cz> References: <1571131302-32290-1-git-send-email-anshuman.khandual@arm.com> <1571150502.5937.39.camel@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Tue 15-10-19 20:51:11, Anshuman Khandual wrote: > > > On 10/15/2019 08:11 PM, Qian Cai wrote: > > The x86 will crash with linux-next during boot due to this series (v5) with the > > config below plus CONFIG_DEBUG_VM_PGTABLE=y. I am not sure if v6 would address > > it. > > > > https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config > > > > [   33.862600][    T1] page:ffffea0009000000 is uninitialized and poisoned > > [   33.862608][    T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff > > ffffff871140][    T1]  ? _raw_spin_unlock_irq+0x27/0x40 > > [   33.871140][    T1]  ? rest_init+0x307/0x307 > > [   33.871140][    T1]  kernel_init+0x11/0x139 > > [   33.871140][    T1]  ? rest_init+0x307/0x307 > > [   33.871140][    T1]  ret_from_fork+0x27/0x50 > > [   33.871140][    T1] Modules linked in: > > [   33.871140][    T1] ---[ end trace e99d392b0f7befbd ]--- > > [   33.871140][    T1] RIP: 0010:alloc_gigantic_page_order+0x3fe/0x490 > > Hmm, with defconfig (DEBUG_VM=y and DEBUG_VM_PGTABLE=y) it does not crash but > with the config above, it does. Just wondering if it is possible that these > pages might not been initialized yet because DEFERRED_STRUCT_PAGE_INIT=y ? Quite likely. You need to wait for page_alloc_init_late to finish. > > [ 13.898549][ T1] page:ffffea0005000000 is uninitialized and poisoned > [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff > [ 13.898549][ T1] raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff > [ 13.898549][ T1] page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) > [ 13.898549][ T1] ------------[ cut here ]------------ > [ 13.898549][ T1] kernel BUG at ./include/linux/mm.h:1107! > [ 13.898549][ T1] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI > [ 13.898549][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc3-next-20191015+ # -- Michal Hocko SUSE Labs