Re: v2.6.26-rc7: BUG: unable to handle kernel NULL pointer dereference

[Jason Wessel <jason.wessel@windriver.com>]

Vegard Nossum wrote:
> On Thu, Jun 26, 2008 at 4:15 AM, Andrew Morton
> <akpm@linux-foundation.org> wrote:
>   
>> Could.  But arch/x86/kernel/smpboot.c is an x86-tree file.  I'd expect
>> the x86 maintainers would like a usable changelog and a Tested-by: (if
>> indeed Vegard tested it).
>>     
>
> Hi,
>
> I had the patch (on top of v2.6.26-rc8) in testing for a couple of
> hours now, but like I expected, the APIC error is really hard to
> reproduce. So I fear that we never hit the failure case in the first
> place. On the other hand... I hit a number of (other?) problems:
>
> 1. Spontaneous reboot. This could have been the APIC error thing, I
> have no way to know. I've never seen this before.
> 2. NULL pointer dereference in pick_next_task_fair(). Not new.
> 3. NULL pointer dereference in page_cgroup_zoneinfo. Never seen this
> before (see screenshot #1).
> 4. Page fault in I'm guessing configure_kgdbts() during boot. Never
> seen this before either (screenshot #2).
>   

How often does #4 occur?

Perhaps you can email me directly the .config and kernel boot arguments
you used?  It would be good to determine if the #4 is a victim or
culprit of the crash.  If it is a culprit I would like to try and fix it.

Thanks,
Jason.