Re: [GIT pull] x86/asm for 5.1

[Thomas Gleixner]

On Sun, 10 Mar 2019, Linus Torvalds wrote:
> On Sun, Mar 10, 2019 at 4:33 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> Finally, I suspect this is all subtly buggy anyway, because your
> 'cr4_pin' thing is a global variable, but the cr4 bits are per-cpu,
> and I don't see how this works with the different CPU's setting things
> up one after each other, but the first one sets the pinned bits.
> 
> So it basically "pins" the bits on CPU's before they are ready, so the
> secondary CPU's maghically get the bits set _independently_ of running
> the actual setup code to set them. That may *work*, but it sure looks
> iffy.

Which I looked at and it's a non issue. The SMAP/SMEP settings are globally
the same and the non-boot CPUs set the bits very early in the boot process.

Thanks,

	tglx