[Buildroot] Two or three stages gcc build?

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Khem,

Any input on the below questions? :-)

Thanks!

Thomas

On Thu, 19 Sep 2013 07:02:55 +0200, Thomas Petazzoni wrote:
> Dear Khem Raj,
> 
> On Fri, 6 Sep 2013 09:59:34 -0700, Khem Raj wrote:
> 
> > > In the mean time, I've experimented a bit and actually implemented it.
> > > The patch hasn't been merged yet in Buildroot, but it has been posted:
> > > http://lists.busybox.net/pipermail/buildroot/2013-September/077344.html.
> > > 
> > > Don't hesitate to have a look and tell me what you think.
> > 
> > OK. The patch looks ok to me. one thing
> 
> After merging the patch, we got a report that it breaks SSP support,
> see [1]. After investigation, depending on the architecture, the
> __stack_chk_fail symbol maybe be part of the TLS (it's the case on x86,
> but on ARM, for example).
> 
> However, since we're now only doing gcc-initial -> uclibc -> gcc-final,
> and gcc-initial has no thread/TLS support, it breaks the build of
> uClibc when SSP support is enabled (in such a case, uClibc is built
> with -fstack-protector, which creates references to __stack_chk_fail,
> but this symbol isn't available because we don't have TLS support).
> 
> Have you already seen this problem? What solution do you suggest?
> 
> Thanks!
> 
> Thomas
> 
> [1]
> http://buildroot-busybox.2317881.n4.nabble.com/uClibc-fails-to-build-with-stack-smash-protection-td51478.html



-- 
Thomas Petazzoni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com