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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1D742C352B6 for ; Mon, 13 Apr 2020 14:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBD072073E for ; Mon, 13 Apr 2020 14:14:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fD9zVjsE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730444AbgDMOOq (ORCPT ); Mon, 13 Apr 2020 10:14:46 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:22781 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730417AbgDMOOp (ORCPT ); Mon, 13 Apr 2020 10:14:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586787283; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9pz4ecCGHpD54VRs30aCWNG0g9ZT3H7m50d0kjdfWfs=; b=fD9zVjsEb4Gp3NZaS9CpwAwDvBDV9Coeb3s0tTDtkoFXvaRlZrTEdJxRWGpwv3ToEJSLs0 KxQ5RcRZQk+R3RhFq4wrJFq0NpuIi4J9iMk9SUxM7HPbt0DQI806OgdbCW5o+whCriCw1Q WUrz68zkfOJroUz0cd5zNv2nZWHCWfk= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-456-CvR-o-1PMPuf_GA8HkEPQg-1; Mon, 13 Apr 2020 10:14:33 -0400 X-MC-Unique: CvR-o-1PMPuf_GA8HkEPQg-1 Received: by mail-qv1-f72.google.com with SMTP id y18so2692811qvx.1 for ; Mon, 13 Apr 2020 07:14:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=9pz4ecCGHpD54VRs30aCWNG0g9ZT3H7m50d0kjdfWfs=; b=hgrsJCqaOiym+aMK+dJ9pX1smwmgQEuQGyQfTtU0GQ8/IOE2HcIGAnuQgdLk01GFsQ 4g9sw9ILyhDWxwKWC1NywZwhpmHHzN6HG9yIZiOkOJjEMtSo/T1XAh3yYVvdu5NZiALy 95swEP9sxskLKI+pCaicAgNAZEX75uYzY8E3Vc0HRJrIbIoyySYsWHTk0YdGoZa6G9rI IIsO9WB7x74elznDbfirCqpddH0684IrlCiXV1lDCPgGfIeyKp56idYyd9QVW8bgX7Zt fez90e2JL7WwBXxSl3f101a8QthMzuvXamIMKyYnorYDFfPUwTsLrgG7PK962odXttm9 GHnA== X-Gm-Message-State: AGi0PubhiaicuoMWhQ8GjDAR3wOVsSfYImupqI/CDYSI6IsoWzM+hmve a5YpHxU5+eXHuPN+bcDipkWlVuEDVtVKDibdc7xJG22dENgKkW4G39TROcMwR2iamgnJ0jBevQT twnjbs/rNPOzJpzqeLMV/Sed2 X-Received: by 2002:a37:bb01:: with SMTP id l1mr16169738qkf.37.1586787272940; Mon, 13 Apr 2020 07:14:32 -0700 (PDT) X-Google-Smtp-Source: APiQypLcyXUmdwZ9EVtC8gVeFjagGEC3vAwbmtSkkop0oHmZV9eVJO4cB8zuzUmSpI+KklOCOl2lAQ== X-Received: by 2002:a37:bb01:: with SMTP id l1mr16169713qkf.37.1586787272633; Mon, 13 Apr 2020 07:14:32 -0700 (PDT) Received: from xz-x1 ([2607:9880:19c0:32::2]) by smtp.gmail.com with ESMTPSA id w2sm2374972qtv.42.2020.04.13.07.14.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Apr 2020 07:14:31 -0700 (PDT) Date: Mon, 13 Apr 2020 10:14:29 -0400 From: Peter Xu To: Naresh Kamboju Cc: open list , "open list:KERNEL SELFTEST FRAMEWORK" , linux-mm , lkft-triage@lists.linaro.org, Shuah Khan , Anders Roxell , Christophe Leroy , Andrew Morton , Leonardo Bras , Michael Ellerman , Mike Rapoport , Arnd Bergmann , Jules Irenge , "Huang, Ying" , Pankaj Gupta , Rik van Riel , Hugh Dickins , Minchan Kim , Mel Gorman , Dave Hansen , Mateusz Nosek , Sebastian Andrzej Siewior , Kees Cook , Vlastimil Babka , Hillf Danton Subject: Re: i386: selftests: vm: compaction_test: BUG: kernel NULL pointer dereference, address: 00000000 Message-ID: <20200413141429.GE38470@xz-x1> References: <20200412214150.GB38470@xz-x1> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 13, 2020 at 04:51:25PM +0530, Naresh Kamboju wrote: > On Mon, 13 Apr 2020 at 03:12, Peter Xu wrote: > > And since this one is very easy to reproduce, I finally noticed that > > we have wrongly enabled uffd-wp on x86_32, which is definely not going > > to work... Because we'll use bit 2 of swap entry assuming that's the > > uffd-wp bit, while that's part of swp offset on 32bit systems. > > > > Naresh, could you try whether below change fixes the issue for you? > > > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > > index 8d078642b4be..7ac524d1316e 100644 > > --- a/arch/x86/Kconfig > > +++ b/arch/x86/Kconfig > > @@ -149,7 +149,7 @@ config X86 > > select HAVE_ARCH_TRACEHOOK > > select HAVE_ARCH_TRANSPARENT_HUGEPAGE > > select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 > > - select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD > > + select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD > > select HAVE_ARCH_VMAP_STACK if X86_64 > > select HAVE_ARCH_WITHIN_STACK_FRAMES > > select HAVE_ASM_MODVERSIONS > > > > Tested-by: Naresh Kamboju > > The above patch tested and did not notice the crash. > + cd /opt/kselftests/default-in-kernel/vm/ > + ./compaction_test > No of huge pages allocated = 297 > + ./compaction_test > [ 46.059785] kauditd_printk_skb: 15 callbacks suppressed > [ 46.059786] audit: type=1334 audit(1586776582.927:25): prog-id=17 op=UNLOAD > [ 46.071997] audit: type=1334 audit(1586776582.927:26): prog-id=16 op=UNLOAD > No of huge pages allocated = 160 > > Full test log, > https://lkft.validation.linaro.org/scheduler/job/1362495#L1308 > > Build artifacts. > https://builds.tuxbuild.com/w0ol7cCsGan0wzPp7bNqkg/ Thanks! I'll post a formal patch soon. -- Peter Xu