Re: [PATCH] percpu: fix first chunk match in per_cpu_ptr_to_phys()

[Tejun Heo <tj@kernel.org>]

On 06/18/2010 02:30 PM, Cliff Wickman wrote:
> On Fri, Jun 18, 2010 at 11:56:16AM +0200, Tejun Heo wrote:
>> per_cpu_ptr_to_phys() determines whether the passed in @addr belongs
>> to the first_chunk or not by just matching the address against the
>> address range of the base unit (unit0, used by cpu0).  When an adress
>> from another cpu was passed in, it will always determine that the
>> address doesn't belong to the first chunk even when it does.  This
>> makes the function return a bogus physical address which may lead to
>> crash.
>>
>> This problem was discovered by Cliff Wickman while investigating a
>> crash during kdump on a SGI UV system.
>>
>> Signed-off-by: Tejun Heo <tj@kernel.org>
>> Reported-by: Cliff Wickman <cpw@sgi.com>
>> ---
>> Can you please verify this one?  I added a small optimization so that
>> it doesn't suck too bad on large machines and it works fine here but
>> it would be great to have your Tested-by:.
> 
> Yep.  Works fine on 32p UV.
> 
> Tested-by: Cliff Wickman <cpw@sgi.com>

Great, thanks.  Will push it to mainline and -stable.

-- 
tejun