Re: [PATCH for 4.5] xen/arm: Initialize the domain vgic lock

[Julien Grall <julien.grall@linaro.org>]

On 18/12/2014 12:12, Ian Campbell wrote:
> On Thu, 2014-12-18 at 12:05 +0000, Julien Grall wrote:
>> Hi Ian,
>>
>> On 18/12/2014 09:47, Ian Campbell wrote:
>>> On Wed, 2014-12-17 at 15:40 +0000, Julien Grall wrote:
>>>> The domain vgic lock is used uninitialized.
>>>>
>>>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>>>
>>> Acked-by: Ian Campbell <ian.campbell@citrix.com>
>>>
>>>> ---
>>>>       This is a bug fix for Xen 4.5 and Xen 4.4. The vgic lock is used
>>>>       unitialized. Luckily we only use the field "raw" which is reset to 0
>>>>       during the domain allocation.
>>>>
>>>>       There is no harm to apply for Xen 4.5 because it will correctly set
>>>>       the spin_lock structure for a later usage.
>>>
>>> By your above reasoning there is also no point, is there? That said, I
>>> think we should take this since as you say it is harmless and good
>>> practice to initialise spinlocks even if not strictly necessary.
>>
>> It's necessary to initialize spinlocks, not all the field of the
>> spinlock is using the value 0 at initialization time.
>
> You said "...we only use the field "raw" which is reset to 0...". Was
> that statement inaccurate?

It's accurate in the current. I should have give more details earlier, 
sorry.

Regards,

-- 
Julien Grall