[CRIU] error in VDSO remap

[Tycho Andersen]

Hi Pavel,

On Tue, Jun 02, 2015 at 08:21:17AM +0300, Pavel Emelyanov wrote:
> On 06/02/2015 06:39 AM, Tycho Andersen wrote:
> > Hi all,
> > 
> > When I try and c/r with current trunk, sometimes I get an error in the
> > vdso remap code. The error message looks garbled (I am using current
> > trunk), so I'm not sure what's really going on. Two examples are:
> > 
> > http://paste.ubuntu.com/11510594/
> > http://paste.ubuntu.com/11511094/
> > 
> > This doesn't happen every time, but maybe 30% of the time.
> > 
> > Any ideas?
> 
> In the kernel code I can find only one reason for the EFAULT from
> mremap -- the region we're trying to remap is not strictly included
> into some single vma. IOW inside the (addr, addr + size) region
> there should be either one whole vma or its part, but no two vmas
> and no holes in the start or end of it.
> 
> Can you stop (sleep 1000) the restoring task right after this message
> and look inside its /proc/self/maps to compare what it remaps vs
> what it really has?

Here's the maps:

http://paste.ubuntu.com/11552302/

and here's my log:

http://paste.ubuntu.com/11552304/

It looks like it's trying to map something onto the end of the last
region? I'm still having trouble parsing the error message, as it
doesn't really match the format string.

Tycho