[PATCH v6 02/14] aarch64: configure test for BTI support

[Szabolcs Nagy]

The 07/07/2020 07:39, H.J. Lu wrote:
> On Tue, Jul 7, 2020 at 7:27 AM Szabolcs Nagy <szabolcs.nagy@arm.com> wrote:
> > i don't know how to reliably link with gcc start files
> > but not with libc start files.
> >
> > explicit link wiht crtbeginS.o may not be right, the
> > exact name depends on the compiler driver.
> >
> > so i would have to provide dummy libc start files to be
> > able to do the check, but that can go bad in many ways
> > so the check may not be reliable.
> 
> For CET, I added --enable-cet to enable CET in GCC run-time,
> including crtbeginS.o, ...  Since CET enabled run-time is backward
> compatible, it is safe to do so.  In fact, --enable-cet is the default
> starting from GCC 10.

makes sense.

on aarch64, bti needs a recent binutils otherwise
there are ugly linker warnings for the unknown gnu
properties so i don't think it's a good idea to
turn it on by default just yet.