Re: Regression - Re: 2.6.28-rc2: runaway loop modprobe char-major-5-1

[Patrick McHardy <kaber@trash.net>]

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.