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=-4.0 required=3.0 tests=BAYES_00,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 54699C4338F for ; Mon, 23 Aug 2021 18:47:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A1CB613CD for ; Mon, 23 Aug 2021 18:47:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230021AbhHWSrp (ORCPT ); Mon, 23 Aug 2021 14:47:45 -0400 Received: from mail-ot1-f48.google.com ([209.85.210.48]:38690 "EHLO mail-ot1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229969AbhHWSro (ORCPT ); Mon, 23 Aug 2021 14:47:44 -0400 Received: by mail-ot1-f48.google.com with SMTP id i8-20020a056830402800b0051afc3e373aso27698555ots.5; Mon, 23 Aug 2021 11:47:01 -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=3/McVAfQzdWCgsaBYCI92abaGtNzjiUr1eGcfPA6e9I=; b=h1qT2W7ynmMkyEFj/3HVsRvBiK3X6BDil5kH64PJcEh+Vn04qcSL6UBA2crZ3c/xQF 1vPWlG8JbOB1yfKQ+KikeGeY77LRibM2lXTeE1D0ECXUOXPeJL4W0YTN555Mz/+whGmR wINwdrcwQMQPvVCS6Q8jQEZTtA8oUVetFexJJcdxYmlAO+C0e9i2QlXPnY9MnYaQLGGW XmG/XnjTCfrBNiH8afkRtRJJTpdDDyqRr/V/tGaG2h6QinTcfo/CRslj+IPTiM95MlQG Se+B8P645zViG2yf/kfFwwfebCFaOGMl2p41KFxV+k5/y1sbXhzRvBBKEjOlK2OpgFR0 dAKA== X-Gm-Message-State: AOAM533DmFrrn4/t+eNz9kUGFSIJGsqCvo2775JTtrKAnX7jpY00T66a mFaC6nj3j5B6NQYCunyXwA== X-Google-Smtp-Source: ABdhPJxbcjQiojN1mwIrX21huEkSPMH+Qj+DGDKN7au8gtOH1WuXaaNQMQAdldSwuAJqA0nhnhb6pQ== X-Received: by 2002:aca:3156:: with SMTP id x83mr12568758oix.124.1629744421524; Mon, 23 Aug 2021 11:47:01 -0700 (PDT) Received: from robh.at.kernel.org (66-90-148-213.dyn.grandenetworks.net. [66.90.148.213]) by smtp.gmail.com with ESMTPSA id c37sm2565548otu.60.2021.08.23.11.47.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Aug 2021 11:47:00 -0700 (PDT) Received: (nullmailer pid 2504374 invoked by uid 1000); Mon, 23 Aug 2021 18:46:59 -0000 Date: Mon, 23 Aug 2021 13:46:59 -0500 From: Rob Herring To: Frank Rowand Cc: Marc Zyngier , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH] of: Don't allow __of_attached_node_sysfs() without CONFIG_SYSFS Message-ID: References: <20210820144722.169226-1-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Sun, Aug 22, 2021 at 11:01:15PM -0500, Frank Rowand wrote: > Hi Marc, > > On 8/20/21 9:47 AM, Marc Zyngier wrote: > > Trying to boot without SYSFS, but with OF_DYNAMIC quickly > > results in a crash: > > > > [ 0.088460] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070 > > [...] > > [ 0.103927] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.14.0-rc3 #4179 > > [ 0.105810] Hardware name: linux,dummy-virt (DT) > > [ 0.107147] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) > > [ 0.108876] pc : kernfs_find_and_get_ns+0x3c/0x7c > > [ 0.110244] lr : kernfs_find_and_get_ns+0x3c/0x7c > > [...] > > [ 0.134087] Call trace: > > [ 0.134800] kernfs_find_and_get_ns+0x3c/0x7c > > [ 0.136054] safe_name+0x4c/0xd0 > > [ 0.136994] __of_attach_node_sysfs+0xf8/0x124 > > [ 0.138287] of_core_init+0x90/0xfc > > [ 0.139296] driver_init+0x30/0x4c > > [ 0.140283] kernel_init_freeable+0x160/0x1b8 > > [ 0.141543] kernel_init+0x30/0x140 > > [ 0.142561] ret_from_fork+0x10/0x18 > > > > While not having sysfs isn't a very common option these days, > > it is still expected that such configuration would work. > > > > Paper over it by bailing out from __of_attach_node_sysfs() if > > CONFIG_SYSFS isn't enabled. > > CONFIG_SYSFS should be automatically selected when CONFIG_OF_DYNAMIC > is enabled, and it should not be possible to disable CONFIG_SYSFS > in this case. That used to be true, but isn't now. Rob