x86-64: new CET-enabled PLT format proposal

[Rui Ueyama]

On Tue, Mar 1, 2022 at 6:27 PM Joao Moreira <joao@overdrivepizza.com> wrote:
>
> > This is what I tried first but I then realized that I needed to insert
> > another `endbr` between `jmp` and `call`. `jmp GOT[foo]` can jump only
> > to `endbr` if CET is enabled, so it can't directly jump to the
> > following `call`.
> >
> Ugh, there we go... dead. Thanks for not letting me waste a ton of time
> :)

I actually wasted my time by implementing it only to find that it
wouldn't work. :) If you are interested, this is my commit to my linker.
https://github.com/rui314/mold/commit/4ec0bbf04841e514aca2000f3d780d14efcaefc9