Re: [PATCH 1/1] x86/fpu: math_state_restore() should not blindly disable irqs

From: Linus Torvalds
Date: Fri Mar 06 2015 - 17:00:23 EST


On Fri, Mar 6, 2015 at 11:23 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
> Please don't. IMO it's really nice that we don't use trap gates at
> all on x86_64, and I find the conditional_sti thing much nicer than
> having to audit all of the entry code to see whether it's safe to run
> it with IRQs on.

So I'm not sure I see much difference, but I'd certainly be ok with
just moving the "conditional_sti()" up unconditionally to be the first
thing in do_device_not_available().

The point being that we still *not* just randomly enable interrupts
because we decide that the callers are wrong.

Linus
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