Re: Regression in 2.6.23-pre Was: Problems with 2.6.23-rc6 on AMDGeode LX800

From: H. Peter Anvin
Date: Wed Sep 26 2007 - 10:10:57 EST


Joerg Pommnitz wrote:
> Hello all,
> this is what git bisect told me about the problem:
>
> jpo@jpo-laptop:~/linux-2.6$ git bisect good
> 4fd06960f120e02e9abc802a09f9511c400042a5 is first bad commit
> commit 4fd06960f120e02e9abc802a09f9511c400042a5
> Author: H. Peter Anvin <hpa@xxxxxxxxx>
> Date: Wed Jul 11 12:18:56 2007 -0700
>
> Use the new x86 setup code for i386
>
> This patch hooks the new x86 setup code into the Makefile machinery. It
> also adapts boot/tools/build.c to a two-file (as opposed to three-file)
> universe, and simplifies it substantially.
>
> Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>
> :040000 040000 6560eb5b7e40d93813276544bced8c478f9067f5 fe5f90d9ca08e526559815789175602ba2c51743 M arch
>

There is something very fishy.

The only documentation you've given us so far is a screen shot which
contained a message ("BIOS data check successful") which doesn't occur
in the kernel.

The loader string doesn't look all that familiar either; it looks like
an extremely old version of SYSLINUX, but that doesn't contain that
message either.

INT 6 is #UD, the undefined instruction exception. This is consistent with:

> Its hitting a bug - specifically (from bootmem.c:125):
> BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);

However, all that tells us is that reserve_bootmem_core() was either
called with a bad address or bdata->node_low_pfn is garbage. In
particular, without knowing how it got there it's hard to know for sure.

Could you send me the boot messages from a working kernel boot?

-hpa

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