[Crash-utility] Re: invalid kernel virtual address: cc08 type: "cpu number (per_cpu)"

[Bob Montgomery]

On Thu, 2009-11-12 at 13:39 +0000, Dave Anderson wrote:
> ----- "Bob Montgomery" <bob.montgomery at hp.com> wrote:

> 
> > In the real smp case, we'll still try to read the small offset (cc08)
> > like an address, but be spared any embarrassment by the QUIET|
> > RETURN_ON_ERROR fix.
> 
> Just to be clear, I think that we agree that:
> 
>  (1) the QUIET|RETURN_ON_ERROR be applied in both functions,
>  (2) the kt->__per_cpu_offset[] NULL-check should be completely dropped
>      in x86_64_per_cpu_init(), and 
>  (3) the kt->__per_cpu_offset[] NULL-check should still be applied in 
>      x86_64_get_smp_cpus() since that loop pre-requires that it's SMP.

I think (3) makes it apparent what we're trying to prevent, but even
without the NULL-check, if we go ahead and access cc08, the QUIET|
RETURN_ON_ERROR fix alone would save us, I think.  Either way my problem
goes away :-)

Is the next version getting close, or do we need to patch 4.1.0
internally for a while?

Bob Montgomery