Re: [PATCH] vm_event: make sure the domain is paused in key domctls

[Razvan Cojocaru <rcojocaru@bitdefender.com>]

On 01/28/2016 04:10 PM, Andrew Cooper wrote:
> On 28/01/16 13:52, Razvan Cojocaru wrote:
>> This patch pauses the domain for all writes through the 'ad'
>> pointer in monitor_domctl(), defers a domain_unpause() call until
>> after the CRs are updated for the MONITOR_EVENT_WRITE_CTRLREG
>> case, and makes sure that the domain is paused for both vm_event
>> enable and disable cases in vm_event_domctl().
>> Thanks go to Andrew Cooper for his review and suggestions.
>>
>> Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
> 
> Would you mind annotating each of the checks for d != current->domain
> with /* no domain_pause(). */, which is our normal practice.

Nice, doing that allowed me to find and modify this code:

1137 #ifdef CONFIG_HAS_MEM_ACCESS
1138     case XEN_DOMCTL_set_access_required:
1139         if ( unlikely(current->domain == d) ) /* no domain_pause() */
1140             ret = -EPERM;
1141         else
1142         {
1143             domain_pause(d);
1144             p2m_get_hostp2m(d)->access_required =
1145                 op->u.access_required.access_required;
1146             domain_unpause(d);
1147         }
1148         break;
1149 #endif

(there was no domain_pause(d) / domain_unpause(d)) before.


Thanks,
Razvan