Re: [PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of user-supplied xstate_header"

From: Ingo Molnar
Date: Sun Sep 24 2017 - 15:01:53 EST



* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Sun, Sep 24, 2017 at 3:59 AM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> > As mentioned before, the patch was too big and too complex, and I've split it
> > up into 10 smaller, bisectable patches:
>
> Is this the (updated) stuff you want to send in for 4.14? Because I
> like this smaller set more tor that than the big series I saw earlier.

It's a 10 patch split-up of one of the 34 patches from the bigger series :-/

> I'm sure the bigger series is a better cleanup, but maybe we can wait with that
> bigger change for 4.15?

So all of this is pretty unfortunate timing, caused in part because I delayed the
FPU changes in this merge window due to having so many x86 changes already.

I'd really love to have the bigger series, firstly because beyond the
simplifications and the fixes in the 10-patch series it also fixes some other
problems such as this SkyLake bug:

0852b374173b: x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on Intel Skylake CPUs

Secondly, with v4.14 being an LTS, doing the cleanups/simplifications afterwards
adds a big backporting barrier.

But I can extract all the fixes and re-structure and re-test it all if you prefer
it that way.

Thanks,

Ingo