Re: UML kernel failed to start betvee 2.6.8-rc8 and current git sources

Jeff Dike
2008-07-10T19:30:58Z

On Thu, Jul 10, 2008 at 08:09:59PM +0200, Toralf Förster wrote:
> At Thursday 10 July 2008 18:35:15 Jeff Dike wrote :
>
> > What's the host?
>
> tfoerste@n22 ~ $ uname -a
> Linux n22 2.6.25-gentoo-r6 #4 Thu Jul 10 19:49:36 CEST 2008 i686 Intel(R) Pentium(R) M processor 1700MHz GenuineIntel GNU/Linux
>
> BTW, this works fine and shows only the config :
> n22 ~ # linux-v2.6.26-rc8-227 --showconfig
>
> whereas this failed:
>
> n22 ~ # linux-v2.6.26-rc9-56 --showconfig
> Locating the bottom of the address space ... 0x0
> Locating the top of the address space ... 0xc0000000

OK, I believe you're seeing the same bug as Uli saw here:

http://marc.info/?l=linux-kernel&m=121011518003727&w=2

More precise symptoms are here:

http://marc.info/?l=linux-kernel&m=121011722806093&w=2

I never did figure that one out. I had the same kernel version, same
toolchain, same everything as far as I could see, and I couldn't
reproduce it, except with a binary that he gave me.

You're seeing it on i386, whereas he saw it on x86_64.

The underlying problem is that somehow the UML initcalls aren't being
run, which is why you're seeing all zeros in the register dump.

If you bisect this, I bet you end up at the no-unit-at-a-time patch
that he ended up at. And I have no idea what that has to do with
anything.