[CRIU] error in VDSO remap

[Pavel Emelyanov]

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?

-- Pavel