Re: [Qemu-devel] [RFC 01/10] target-arm: protect cpu_exclusive_*.

[Paolo Bonzini]

On 03/03/2015 16:33, Mark Burton wrote:
> 
>> On 3 Mar 2015, at 16:32, Paolo Bonzini <address@hidden> wrote:
>>
>>
>>
>> On 03/03/2015 16:29, Mark Burton wrote:
>>>
>>> ps. on our bug - we believe somehow the STREX is being marked as
>>> failed, but actually succeeds to write something.  There are only 3
>>> ways the strex can fail: 1/ the address doesn't match - in which case
>>> no ST will be attempted 2/ the value doesn't match - which means - no
>>> ST attempted 3/ the store starts, but causes a TLB fill/exception…
>>>
>>> The 3rd has 2 possibilities - the TLB is filled, and the store goes
>>> ahead totally normally - there should be no ‘fail’ - or an exception
>>> is generated in which case we will long jump away and never return.
>>
>> When do you release the lock?
>>
> (Thanks Paolo!)
> 
> We release the lock in either
> a) the end of the strex
> or
> b) in the ‘raise_exception’

That seems right... Can you post the patch?

Paolo