Re: libxl: cannot start guest

[Christoph Egger <Christoph.Egger@amd.com>]

On 05/22/12 15:21, Ian Campbell wrote:

> On Tue, 2012-05-22 at 14:18 +0100, Christoph Egger wrote:
>> I thinkIn xs_talkv() something must fail.
>>
>>> The only thing which springs to mind is that it may generate an
>>> @IntroduceDomain watch event. However xl is single threaded so we won't
>>> process that event until we unwind to whichever point we do an event
>>> loop iteration, in which case the corruption would have to happen later
>>> than right after xs_introduce_domain().
>>>
>>> Did you manage to determine if "Bad file descriptor" was due to it being
>>> closed vs. the value being corrupted?
>>
>> My suspicion is that
>>
>>    if (msg.type != type)
>>
>> in xs_talkv() is true.
>>
> 
> Yes, that definitely seems worth investigating.


Ok, I got it.

xenstored crashes due to dereferencing NULL pointer.

In xenstored_domain.c, map_interface()  *xcg_handle is NULL
and in xc_gnttab.c, xc_gnttab_map_grant_ref() it is dereferenced.

Christoph



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