Re: Recent removal of a.out and COFF support for sparc

[Andrew Pinski <pinskia at gmail dot com>]

On Wed, Aug 8, 2018 at 2:23 PM John Paul Adrian Glaubitz
<glaubitz@physik.fu-berlin.de> wrote:
>
> On 08/08/2018 08:27 PM, Maciej W. Rozycki wrote:
> > On Wed, 8 Aug 2018, John Paul Adrian Glaubitz wrote:
> >
> >>> Gold supports only a small fraction of the platforms that BFD does,
> >>
> >> Which of the platforms that are still relevant for commercial applications
> >> are supported by BFD which are not supported by Gold?
> >>
> >> As far as I know, Gold support x86*, POWER*, ARM*, s390* and MIPS* which
> >> covers all of the targets that distributions like Fedora, openSUSE and
> >> Debian consider as supported release architectures.
> >
> >  We have dozens of bare metal targets which only have support in BFD.
>
> Which is my whole point. If you remove all these targets from BFD, what
> would be the point of still using it over Gold or LLVM's LLD?
>
> It's the same argument I see with gcc. One of it's huge selling points
> is the plethora of targets it supports. If you go ahead now and cut
> out all targets except for the current mainstream targets, you are
> removing one huge advantage that gcc has over LLVM.

If people would step up, it would not be such an issue.
Take a look at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86772 .
All of the unconfirmed bug reports linked against this meta-bug about
a possible security in generated code.
Yes most of the targets that are left are in-order and won't have this
issue but it just shows which targets are not being maintained.
This bug report shows what targets are have actual maintainace.  And
people can't complain about their favorite target getting removed if
it has an obvious possible security hole happening.
Also you can see there are some "non-mainstream" targets which have
been fixed including m68k and xstormy16.

Thanks,
Andrew


>
> > Some of these architectures happen to have Linux support too, for embedded
> > applications.  All the world is not Linux.  And all the world are not
> > distributions either.  Freescale S12Z is the most recent addition I
> > believe, and has no gold support AFAICT.
>
> Yep. And that's why I think it's better to keep BFD useful for various
> targets and not bother about potential vulnerabilities which don't really
> pose a threat in the real world, e.g. the threat that someone is sending
> a user a manipulated object file and asking them to open it with "readelf"
> or "objcopy" running as root.
>
> Adrian
>
> --
>  .''`.  John Paul Adrian Glaubitz
> : :' :  Debian Developer - glaubitz@debian.org
> `. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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