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

[Linus Torvalds]

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.

             Linus