[Olsr-dev] compile error on native ARMv7 / Ubuntu15.04

Bastian Bittorf (spam-protected)
Mon Nov 9 14:25:05 CET 2015

* Henning Rogge <(spam-protected)> [09.11.2015 13:54]:
> > (so only add it when NOT crosscompiling)
> This would be just a crude hack...
> on some platforms you will need fPIC... it doesn't matter if you
> crosscompile for them or not.

hmmm...the problem is at least solved for OpenWrt,
because there are specific platform optimizations added.

> on others you don't need it, don't want it (or cannot use it?).

you can always use it, but it has performance issues on some arch's.

> Does someone know the size difference between fPIC executables and
> "normal ones"?

numbers for olsrd

ARMv7: (the daemon itself does compile withpout PIC, but not cfgfile_gen.o) 
  987.344 olsrd -> make
1.005.288 olsrd -> make EXTRA_CFLAGS=-fPIC

1.111.838 olsrd -> make
1.146.205 olsrd -> make EXTRA_CFLAGS=-fPIC

so: it adds about 20k-30k unstripped.
> And does OpenWRT support address layout randomization?

only when enabled ("hardening kernel").

bye, bastian

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