Re: [GIT pull] x86/pti updates for 4.15

From: Thomas Gleixner
Date: Sun Jan 14 2018 - 16:01:52 EST


On Sun, 14 Jan 2018, Linus Torvalds wrote:
> On Sun, Jan 14, 2018 at 7:27 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-pti-for-linus
>
> So I do think this:
>
> $(warning CONFIG_RETPOLINE=y, but not supported by the
> compiler. Toolchain update recommended.)
>
> needs to be removed.
>
> Yes, yes, I understand why it's warning. It's still both annoying and wrong.
>
> It's wrong because it will just make people turn off RETPOLINE, and
> the asm updates - and return stack clearing - that are independent of
> the compiler are likely the most important parts because they are
> likely the ones easiest to target.
>
> And it's annoying because most people won't be able to do anything
> about it. The number of people building their own compiler? Very
> small. So if their distro hasn't got a compiler yet (and pretty much
> nobody does), the warning is just annoying crap.
>
> It is already properly reported as part of the sysfs interface. The
> compile-time warning only encourages bad things.

Good point. I'll queue a patch to that effect or do you just want to do
that yourself?

Thanks,

tglx