Use stable sort for ld -r relocs

[Mike Frysinger]

On 27 Aug 2015 10:58, Alan Modra wrote:
> On Wed, Aug 26, 2015 at 06:04:41PM -0400, Mike Frysinger wrote:
> > On 26 Aug 2015 23:32, Alan Modra wrote:
> > > A number of targets emit multiple relocs at a given r_offset, and
> > > depend on those relocs staying in their original order.  qsort doesn't
> > > satisfy this requirement, although it appears from my non-rigorous
> > > testing that glibc's msort.c implementation may in fact be stable.
> > > 
> > > I made the mistake of backporting my PR 17666 fix to 2.25.1, thinking
> > > the code had enough time to settle on mainline, but for anyone with a
> > > system libc that provides an unstable qsort this will mean 2.25.1
> > > ld -r may be broken on some targets.
> > > 
> > > 	PR 18867
> > > 	* elflink.c (cmp_ext32l_r_offset, cmp_ext32b_r_offset): Delete.
> > > 	(cmp_ext64l_r_offset, cmp_ext64b_r_offset): Delete.
> > > 	(ext32l_r_offset, ext32b_r_offset, ext64l_r_offset, ext64b_r_offset):
> > > 	New functions.
> > > 	(elf_link_adjust_relocs): Use an insertion sort to sort relocs.
> > 
> > were you planning on making another change ?  i tested master
> > (1dc7a6235090327d7b5586f85e6115c3cd13ed83) and it still crashes
> > on alpha.  this hack makes things work:
> > --- a/bfd/elflink.c
> > +++ b/bfd/elflink.c
> > ...
> > -      sort = bed->sort_relocs_p == NULL || (*bed->sort_relocs_p) (o);
> > +      sort = 0; //bed->sort_relocs_p == NULL || (*bed->sort_relocs_p) (o);
> 
> Yes, I'm going to turn off reloc sorting on alpha.

thanks, that works.  planning on putting both fixes into the 2.25 branch too ?
-mike