fix building crash driver on s390

[Josh Boyer]

On Tue, Nov 26, 2013 at 06:30:33PM +0100, Dan Horák wrote:
> On Tue, 26 Nov 2013 08:10:24 -0500
> Josh Boyer <jwboyer at redhat.com> wrote:
> 
> > On Tue, Nov 26, 2013 at 12:31:53PM +0100, Dan Horák wrote:
> > > Hi,
> > > 
> > > currently the crash driver is disabled in rawhide, but enabled as
> > > module in f20 and stabilization branch. The following snippet make
> > > it build on s390
> > > 
> > > diff -up a/arch/s390/mm/maccess.c.crash b/arch/s390/mm/maccess.c
> > > --- a/arch/s390/mm/maccess.c.crash	2013-11-26
> > > 10:51:55.188222879 -0500 +++ b/arch/s390/mm/maccess.c
> > > 2013-11-26 10:52:43.718223592 -0500 @@ -228,3 +228,6 @@ void
> > > unxlate_dev_mem_ptr(unsigned long a if ((void *) addr != buf)
> > >  		free_page((unsigned long) buf);
> > >  }
> > > +
> > > +EXPORT_SYMBOL(xlate_dev_mem_ptr);
> > > +EXPORT_SYMBOL(unxlate_dev_mem_ptr);
> > > 
> > > I think it should get appended to the crash driver patch.
> > 
> > Is this something anyone is in a position to test on s390x?  I'm fine
> > with adding it to the patch, but if nobody is going to use crash on
> > s390x I'm curious if we should leave it enabled.
> 
> crash itself is maintained by IBM for s390x, so I guess we should keep all
> arches the same when possible. Kyle probably has more information.
> 
> I just tried the command from rhbz#492803
> crash -d7 /usr/lib/debug/lib/modules/3.13.0-0.rc1.git2.1.fc21.s390x/vmlinux
> on kernel with the crash driver enabled and it works if I can see.

OK.

josh