Re: [PATCH v3 04/22] x86/doublefault: Make memmove() notrace/NOKPROBE

From: Steven Rostedt
Date: Wed Feb 19 2020 - 10:55:18 EST

On Wed, 19 Feb 2020 16:40:31 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> > Hmm, for things like this, which is adding notrace because of a single
> > instance of it (although it is fine to trace in any other instance), it
> > would be nice to have a gcc helper that could call "memmove+5" which
> > would skip the tracing portion.
> Or just open-code the memmove() in do_double_fault() I suppose. I don't
> think we care about super optimized code there. It's the bloody ESPFIX
> trainwreck.

Or just create a memmove_notrace() version and use that.

-- Steve