Re: [PATCH 3 of 7] IOMMU: Sanitise pointer work

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 13/06/11 19:13, Keir Fraser wrote:
> On 13/06/2011 18:02, "Andrew Cooper" <andrew.cooper3@citrix.com> wrote:
>
>> Check for null pointers before calling function pointers.
> But they're never NULL? This one's a bit pointless.
>
>  -- Keir
>
This patch was a direct result of comments regarding my previous attempt
to make a crash_shutdown iommu_op.  Are we happy to assume that noone in
the future is going to partially implement an iommu_ops structure?

~Andrew
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>>
>> diff -r 1c3d2e4d06fe -r 68efd418b6f1 xen/drivers/passthrough/iommu.c
>> --- a/xen/drivers/passthrough/iommu.c Mon Jun 13 17:45:43 2011 +0100
>> +++ b/xen/drivers/passthrough/iommu.c Mon Jun 13 17:45:43 2011 +0100
>> @@ -407,17 +407,17 @@ unsigned int iommu_read_apic_from_ire(un
>>      return ops->read_apic_from_ire(apic, reg);
>>  }
>>  
>> -void iommu_resume()
>> +void iommu_resume(void)
>>  {
>>      const struct iommu_ops *ops = iommu_get_ops();
>> -    if ( iommu_enabled )
>> +    if ( iommu_enabled && ops && ops->resume )
>>          ops->resume();
>>  }
>>  
>> -void iommu_suspend()
>> +void iommu_suspend(void)
>>  {
>>      const struct iommu_ops *ops = iommu_get_ops();
>> -    if ( iommu_enabled )
>> +    if ( iommu_enabled && ops && ops->suspend )
>>          ops->suspend();
>>  }
>>  
>>
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>

-- 
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com