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

Mike Travis
2008-06-23T16:58:59Z

Rusty Russell wrote:
> On Monday 23 June 2008 02:29:07 Vegard Nossum wrote:
>> And the (cpu < nr_cpu_ids) fails because the CPU has just been
>> offlined (or failed to initialize, but it's the same thing), while
>> NR_CPUS is the value that was compiled in as CONFIG_NR_CPUS (so the
>> former check will always be true).
>>
>> I don't think it is valid to ask for a per_cpu() variable on a CPU
>> which does not exist, though
>
> Yes it is. As long as cpu_possible(cpu), per_cpu(cpu) is valid.
>
> The number check should be removed: checking cpu_possible() is sufficient.
>
> Hope that helps,
> Rusty.

I don't see a check for index being out of range in cpu_possible().

Thanks,
Mike