From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753291AbYKXPGB (ORCPT ); Mon, 24 Nov 2008 10:06:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751178AbYKXPFx (ORCPT ); Mon, 24 Nov 2008 10:05:53 -0500 Received: from ey-out-2122.google.com ([74.125.78.24]:38659 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751095AbYKXPFx (ORCPT ); Mon, 24 Nov 2008 10:05:53 -0500 Message-ID: Date: Mon, 24 Nov 2008 16:05:51 +0100 From: "Kay Sievers" To: "Patrick McHardy" Subject: Re: Regression - Re: 2.6.28-rc2: runaway loop modprobe char-major-5-1 Cc: "Meelis Roos" , "Linux Kernel list" In-Reply-To: <492AACB4.9070903@trash.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <49071A84.3080706@trash.net> <492AACB4.9070903@trash.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 24, 2008 at 14:31, Patrick McHardy wrote: > Meelis Roos wrote: >>>> >>>> request_module: runaway loop modprobe char-major-5-1 >>>> >>>> and then hangs. >>>> >>>> char-major-5-1 seems to mean ttyS0. >>> >>> I'm seeing the same problem on a Debian unstable system using >>> initramfs and dm-crypt, but it seems to be caused by userspace >>> changes, using an old initramfs image with just the new modules >>> added manually works fine (well, breaks elsewhere). >> >> I have done some eveninfs testing, taking apart and putting together my >> own initramfs. It looks like this is a kernel bug, not userspace - the hang >> happens after initramfs is unpacked and after VFS and quotas are installed, >> and after "msgmni has been set to 627" message but before BSG loading >> message and before io scheduler initialization. And log before init is >> executed from initramfs (and no modprobe is executed either, as my wrapper >> does not run). >> >> Rerepeating, same userspace generats fine initramfs for 2.6.27 and the >> initramfs contents are the same except modules tree that is for different >> version. >> >> It happens on 2 of my computers, both have custom config (serial compiled >> in, not modular). The hang happens before ttyS driver initialization. > > char-major-5-1 is /dev/console here. > >> Seems like a kernel regression to me. > > It does, I changed some configuration options from =m to =y and > it started working again. Unfortunately I'm unable to find the > exact option that fixed it since I don't have the previous > configuration anymore and random attempts to trigger the problem > again failed. Maybe you just miss /dev/console in initramfs? That would trigger the kernel forked modprobe with that major/minor. Some device nodes must be created or included in initramfs before any action is taken. Kay