Re: [tip: x86/core] objtool: Find unused ENDBR instructions

From: Josh Poimboeuf
Date: Thu Mar 17 2022 - 18:23:04 EST


On Tue, Mar 15, 2022 at 03:39:52PM +0000, David Laight wrote:
> From: Peter Zijlstra
> >
> > objtool: Find unused ENDBR instructions
> >
> > Find all ENDBR instructions which are never referenced and stick them
> > in a section such that the kernel can poison them, sealing the
> > functions from ever being an indirect call target.
>
> Thought, what happens if the only indirect call is from
> code in a module?

Then <boom>, I guess. Is it safe to assume in-tree modules don't need
to do indirect calls to exported functions? I guess we'll find out :-)

--
Josh