Re: STI architectural question (and lretq -- I'm not even kidding)

[Borislav Petkov]

On Tue, Jul 22, 2014 at 06:03:35PM -0700, Linus Torvalds wrote:
> So I'm afraid that "sti; lret" is not guaranteed to be architecturally
> NMI-safe. But it *might* be safe on certain micro-architectures, and
> maybe somebody inside Intel or AMD can give us a hint about when it is
> safe and when it isn't.

>From AMD's APM, STI section:

"Sets the interrupt flag (IF) in the rFLAGS register to 1, thereby
allowing external interrupts received on the INTR input. Interrupts
received on the non-maskable interrupt (NMI) input are not affected by
this instruction."

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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