[PATCH 0/5] x86: CVE-2017-5715, aka Spectre

[Uros Bizjak]

On Sun, Jan 14, 2018 at 9:34 PM, David Woodhouse <dwmw2@infradead.org> wrote:

> Likewise, the CONFIG_TRIM_UNUSED_SYMBOLS mechanism in the kernel passes
> .S files through the preprocessor and looks for EXPORT_SYMBOL, so it
> wasn't working well with my .irp-based implementation like the one in
> Xen. So I've swapped it out for this one for now.
>
> Again, I was hoping to clean that up and make it do something saner,
> and then this could switch back too.
>
> But sure, right now it isn't that might of a difference for me; my
> implementation has changed since I made that reqeust. I have no
> fundamental technical objection to the bare 'ax' naming. We can live
> with either.
>
> It's just that we've been asking for an agreement on the basics (the
> command line we use, and the thunk names) for some days now, and this
> is the first time we've had this discussion, and Linus has just taken
> the patches.
>
> That's still fine. I know we get no sympathy, and we *can* change the
> Linux kernel between -rc8 and -final if we must, and change the Xen
> patches too. I'd just rather not.

Well, you did say that these are strange times ;)

>From the user perspective, it would be more convenient to use the
thunk names that are the same for 32bit and 64bit targets. If we
ignore this fact, the difference is only a couple of lines in the
compiler source which we also can live with. But please discuss my
proposal also in the kernel community, and weight the benefits and
drawbacks of each approach before the final decision.

Please pass the final decision to gcc community, and we'll implement it.

Uros.