[Xenomai] Won`t build on new Debian Stable

Henning Schild henning.schild at siemens.com
Fri Oct 13 12:26:53 CEST 2017


Am Fri, 13 Oct 2017 11:37:30 +0200
schrieb Norbert Lange <nolange79 at gmail.com>:

> Actually your idea of just adding -r would work aswell, and looks
> cleaner and more robust to me.

Ok, in that case it would still be nice to understand why it works and
what "-r" does to gcc.

If you like that better send another patch and we will see what
Philippe says.

Henning

> I started with the wrong ideas because of the usual POSIX argument
> parsing like "tar -xzf file.tar.gz" being interpreted as  "tar -x -z
> -f file.tar.gz".
> 
> 2017-10-13 11:31 GMT+02:00 Henning Schild
> <henning.schild at siemens.com>:
> > That looks good to me.
> >
> > Henning
> >
> > Am Fri, 13 Oct 2017 10:38:26 +0200
> > schrieb Norbert Lange <nolange79 at gmail.com>:
> >  
> >> Second attempt at fixing it, you could surely make this more
> >> complex using autohell but I am not going there.
> >>
> >> If I understood correctly this script is only necessary if the
> >> application is linked -static?
> >> Means I would try to avoid using it, aslong I dont explicitly want
> >> to do that.
> >>
> >> Kind regards,
> >> Norbert
> >>
> >> 2017-10-13 9:40 GMT+02:00 Norbert Lange <nolange79 at gmail.com>:  
> >> > Ok I just realized there is a "-Ur" option, aside from "-U -r".
> >> >
> >> > You get alot otherwise undocumented flags with "gcc --help -v"
> >> > BTW
> >> >
> >> > 2017-10-13 9:13 GMT+02:00 Norbert Lange <nolange79 at gmail.com>:  
> >> >> Hello,
> >> >>
> >> >> I tracked down the source of information to this:
> >> >> https://wiki.ubuntu.com/SecurityTeam/PIE
> >> >>
> >> >> I changed the flags from "-Wl,-Ur" to "-Wl,-U -r", so you wont
> >> >> get an explanation from me, why -U has to be passed for the
> >> >> linker. And by the way, gcc accepts -U aswell, so this might be
> >> >> preferable to be used directly too.
> >> >>
> >> >> I don`t know why those flags aren' t documented, bug in gcc
> >> >> documentation? As far as I understand is that gcc is smart
> >> >> enough to correctly deal with the flags gcc directly received,
> >> >> but the linker lacks that information.
> >> >>
> >> >> I don' t know what the issue is with the C++ Constructors, in
> >> >> the context of this change?
> >> >> (I heard about the issues if those reside in a shared library,
> >> >> use function from libcobald and don't depend on libcobald.
> >> >> Which is more of a broken build to me if you don't add the
> >> >> depended libs, and will bite you the same way if you use GCCs
> >> >> constructor attribute)
> >> >>
> >> >> Kind regards,
> >> >> Norbert.
> >> >>
> >> >> 2017-10-12 10:33 GMT+02:00 Henning Schild
> >> >> <henning.schild at siemens.com>:  
> >> >>> Hey Norbert,
> >> >>>
> >> >>> thanks for looking into that again! Could you please explain
> >> >>> how and why that works, or point out what to look at in flint?
> >> >>> Mailing list thread, commit, something like that.
> >> >>>
> >> >>> As far as i can see gcc now gets a "-r" which i do not find in
> >> >>> the manpage. And ld gets a "-U" which i do not find in its
> >> >>> manpage. And there is something about c++ constructors which
> >> >>> might change the behaviour of xenomai.
> >> >>>
> >> >>> Henning
> >> >>>
> >> >>> Am Tue, 10 Oct 2017 16:38:50 +0200
> >> >>> schrieb Norbert Lange <nolange79 at gmail.com>:
> >> >>>  
> >> >>>> Some highly trivial fix attached!
> >> >>>> Its strange that this flag is not documented in the manual (I
> >> >>>> found out abaout this fix from
> >> >>>> https://launchpad.net/ubuntu/+source/flint)
> >> >>>>
> >> >>>> Norbert Lange
> >> >>>>
> >> >>>> 2017-08-10 11:49 GMT+02:00 Henning Schild
> >> >>>> <henning.schild at siemens.com>:  
> >> >>>> > Hi Norbert,
> >> >>>> >
> >> >>>> > Thanks! In fact that issue has come up before and a similar
> >> >>>> > workaround was described. It should be fixed, patches
> >> >>>> > welcome!
> >> >>>> >
> >> >>>> > Henning
> >> >>>> >
> >> >>>> > Am Wed, 9 Aug 2017 16:21:02 +0200
> >> >>>> > schrieb Norbert Lange <nolange79 at gmail.com>:
> >> >>>> >  
> >> >>>> >> Hello,
> >> >>>> >>
> >> >>>> >> Building the xenomai package won`t work because debian now
> >> >>>> >> defaults to using pie, and the linker will complain with
> >> >>>> >> "ld: -r and -pie may not be used together"
> >> >>>> >>
> >> >>>> >> A workaround for now is to add the flags manually:
> >> >>>> >> ../xenomai-3.0.5/configure LDFLAGS=-no-pie CFLAGS="-fno-PIE
> >> >>>> >> -fno-pie -no-pie"
> >> >>>> >>
> >> >>>> >> A real fix would be similar to
> >> >>>> >> http://lists.gnu.org/archive/html/bug-grub/2016-11/msg00011.html
> >> >>>> >> (no-pie is not supported on old and other compilers)
> >> >>>> >>
> >> >>>> >> Kind regards,
> >> >>>> >> Norbert
> >> >>>> >>
> >> >>>> >> _______________________________________________
> >> >>>> >> Xenomai mailing list
> >> >>>> >> Xenomai at xenomai.org
> >> >>>> >> https://xenomai.org/mailman/listinfo/xenomai  
> >> >>>> >  
> >> >>>  
> >  




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