[CRIU] Re: [PATCH 3/4] restorer: Do restore futex robust lists

[Cyrill Gorcunov]

On Fri, Aug 10, 2012 at 12:12:24PM +0400, Stanislav Kinsbursky wrote:
> 10.08.2012 12:03, Cyrill Gorcunov пишет:
> >On Fri, Aug 10, 2012 at 11:52:33AM +0400, Pavel Emelyanov wrote:
> >>On 08/10/2012 10:23 AM, Cyrill Gorcunov wrote:
> >>>On Fri, Aug 10, 2012 at 06:43:04AM +0400, Pavel Emelyanov wrote:
> >>>>On 08/09/2012 09:36 PM, Cyrill Gorcunov wrote:
> >>>>>Updated version attached
> >>>>
> >>>>Looks OK. One question:
> >>>>
> >>>>>+	if (core->thread_info->has_futex_rla &&
> >>>>>+	    core->thread_info->has_futex_rla_len) {
> >>>>
> >>>>What guarantees, that the optional fields will be set
> >>>>to zero when absent?
> >>>
> >>>This is done by pb library.
> >>
> >>Even if you don't specify the default value?
> >
> >Yes, it's a bit tricky :) Lets look at protobuf source code
> 
> It this set to zero is a part of the protocol, then it's alright.
> But if it's just a trick in current implementation - then we can't rely on it.

Well, it should be part of ABI, otherwise a bunch of programs which
use pb will fail on update.

	Cyrill