From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: linux-next: Tree for Jan 20 -- Kernel panic - Unable to mount root fs Date: Wed, 21 Jan 2015 09:51:15 -0800 Message-ID: <54BFE713.20807@roeck-us.net> References: <20150120165655.GA10904@kria> <20150121153910.GD22884@ulmo.nvidia.com> <20150121155407.GA18701@kria> <6942214.D1ODllqz3j@sifl> <20150121173810.GP29656@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Sabrina Dubroca , Thierry Reding , Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-audit@redhat.com, Richard Guy Briggs To: Al Viro , Paul Moore Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:48407 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752198AbbAURvY (ORCPT ); Wed, 21 Jan 2015 12:51:24 -0500 Received: from mailnull by bh-25.webhostbox.net with sa-checked (Exim 4.82) (envelope-from ) id 1YDzR5-002vbm-R3 for linux-fsdevel@vger.kernel.org; Wed, 21 Jan 2015 17:51:24 +0000 In-Reply-To: <20150121173810.GP29656@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 01/21/2015 09:38 AM, Al Viro wrote: > On Wed, Jan 21, 2015 at 11:16:23AM -0500, Paul Moore wrote: >> On Wednesday, January 21, 2015 04:54:07 PM Sabrina Dubroca wrote: >>> 2015-01-21, 16:39:12 +0100, Thierry Reding wrote: >>>> That doesn't seem to help, at least in my case. >>> >>> Same here. >> >> Okay, thanks for trying. Sorry that didn't resolve things. >> >>> Well, it's probably not an audit issue. I tried audit=0 on the >>> commandline, and I just rebuilt a kernel with CONFIG_AUDIT=n, and it's >>> still panicing. This should have fixed any audit-related issue, >>> right? >> >> Most likely. Back to the code I go ... > > FWIW, I really wonder if populate_rootfs() (run ultimately from > kernel_init(), by way of kernel_init_freeable(), do_basic_setup() and > do_initcalls()) ends up with some side effects as far as struct filename > are concerned... > > Note that if we _ever_ hit reuse logics there, we are going to get bogus > matches asoddingplenty - *all* those sys_mkdir(), etc. are going to be > with filenames in the same reused buffer. So if anything in there leaks > from one call to another, we are going to have a mess on hands. > > Another place where that can be a problem is devtmpfs - there's a kernel > thread doing actual mkdir, mknod, etc. in that abomination and if _that_ > ends up accumulating aushit entries, we'll end up with interesting problems. > > Folks, could you print the value of audit_dummy_context() in populate_rootfs() > and in drivers/base/devtmpfs.c:devtmpfsd()? > populate_rootfs: audit_dummy_context() returns 1 Guenter