From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jim Fehlig <jfehlig@suse.com>
Subject: Re: [PATCH 2/2] libxl: fix stale timeout event callback
 race
Date: Thu, 13 Dec 2012 08:57:54 -0700
Message-ID: <50C9FB02.7010204@suse.com>
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To: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>, Ian Campbell <Ian.Campbell@citrix.com>, Bamvor Jian Zhang <bjzhang@suse.com>
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Ian Jackson wrote:
> Jim Fehlig writes ("Re: [Xen-devel] [PATCH 2/2] libxl: fix stale timeout event callback race"):
>   
>> Yes, after thinking about it some more, I agree.
>>
>> As for the modify callback, do you agree that it is fine to ignore the
>> timeval parameter and just update the timer in libvirt's event loop to
>> fire immediately?  I.e. always treat the timeval parameter as containing
>> {0,0} regardless of "old" or "new" libxl?
>>     
>
> Yes.  That is fine.
>
> The reason is that old libxl doesn't ever call this function and new
> libxl always calls it with {0,0}.  If you're worried about this, add
> an assertion :-).  But it's theoretical.
>
>   
>> I think my patch here is correct
>> http://lists.xen.org/archives/html/xen-devel/2012-12/msg00985.html
>>     
>
> Having thought about it, I agree, provided that you also fix the
> potential integer overflow in libxlTimeoutRegisterEventHook.
>   

Right.  I'll squash a fix to handle that into my current patch and send
it to the libvirt dev list, cc'ing xen-devel too.

Regards,
Jim