Re: [PATCH v2 4/4] x86/static_call: Add inline static call implementation for x86-64
From: Linus Torvalds
Date: Thu Nov 29 2018 - 12:54:50 EST
On Thu, Nov 29, 2018 at 9:50 AM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> - corrupt random registers because we "know" they aren't in use
Just to clarify: I think that's a completely unacceptable model.
We already have lots of special calling conventions, including ones
that do not have any call-clobbered registers at all, because we have
special magic calls in inline asm.
Some of those might be prime material for doing static calls (ie PV-op
stuff, where the native model does *not* change any registers).
So no. Don't do ugly hacks like that.
Linus