ld.gold error unsupported -mbss-plt code

[Chris Packham]

Hi Alan,

On Wed, Jul 24, 2024 at 2:00 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Wed, Jul 24, 2024 at 10:32:52AM +1200, Chris Packham wrote:
> > error: liblxcfs.so.p/src_bindings.c.o: unsupported -mbss-plt code
> > ...
> >
> > I don't really understand what ld.gold is complaining about.
>
> Around 2007, the powerpc ABI (and gcc and binutils) gained what I
> called secure-plt.  Prior to that, the powerpc plt section was a bss
> section that was written with code generated by ld.so.  This required
> a section that was both writable and executable, and therefore
> somewhat of a target for malicious code.  The new secure-plt ABI
> doesn't use an executable plt, but the code generated to make a call
> via the plt is a little slower than bss-plt in moderately sized
> executables and libraries.  Your gcc might be configured to generate
> bss-plt code by default, so to use ld.gold when linking shared
> libraries or PIEs you'd need to pass -msecure-plt to gcc when
> compiling.  If your project has assembly that makes bss-plt style
> calls then more work will be needed.

Thanks for the explanation. I think specifying -msecure-plt helps
reduce the number of errors but I still have the problem that
crtbeginS.o from the toolchain obviously still has the bss-plt style.
There might be some incantation I can pass to change how that's
generated but I'll take the easy way out and just disable ld.gold in
that configuration.