Re: [PATCH] Fix NULL pointer for Xen guests

[Prarit Bhargava <prarit@redhat.com>]

On 04/28/2010 02:26 PM, Andrew Morton wrote:
> On Tue, 27 Apr 2010 11:24:42 -0400
> Prarit Bhargava<prarit@redhat.com>  wrote:
>
>    
>> Upstream PV guests fail to boot because of a NULL pointer.  It is possible that
>> xen guests have irq_desc->chip_data = NULL.
>>
>> Test for NULL chip_data pointer before attempting to complete an irq move.
>>
>> Signed-off-by: Prarit Bhargava<prarit@redhat.com>
>> Acked-by: Suresh Siddha<suresh.b.siddha@intel.com>
>>
>> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
>> index 127b871..eb2789c 100644
>> --- a/arch/x86/kernel/apic/io_apic.c
>> +++ b/arch/x86/kernel/apic/io_apic.c
>> @@ -2545,6 +2545,9 @@ void irq_force_complete_move(int irq)
>>   	struct irq_desc *desc = irq_to_desc(irq);
>>   	struct irq_cfg *cfg = desc->chip_data;
>>
>> +	if (!cfg)
>> +		return;
>> +
>>   	__irq_complete_move(&desc, cfg->vector);
>>   }
>>   #else
>>      
> I assume this is needed for 2.6.34?
>
> What about 2.6.33.x and earlier?
>    

Hey Andrew,

I actually pinged Chris Wright to see about including this in the 
-stable branches.  I haven't heard anything back so I'll reping him.

P.