Re: [patch V4 part 1 35/36] x86: Replace ist_enter() with nmi_enter()

[Andy Lutomirski]

On Tue, May 5, 2020 at 7:14 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>
> A few exceptions (like #DB and #BP) can happen at any location in the code,
> this then means that tracers should treat events from these exceptions as
> NMI-like. The interrupted context could be holding locks with interrupts
> disabled for instance.
>
> Similarly, #MC is an actual NMI-like exception.

Is it permissible to send a signal from inside nmi_enter()?  I imagine
so, but I just want to make sure.

--Andy