Re: change "microcode: Use fallthrough attribute on clang 10 and 11 too." broke the build for me

[Chris Hanson]

OK, thanks. So this doesn't affect older machines like mine.

Sigh. That's a pain in the ass. It's a significant amount of work, and 
not the fun kind either.

On 2/15/21 2:36 PM, Taylor R Campbell wrote:
> > Date: Mon, 15 Feb 2021 14:20:22 -0800
> > From: Chris Hanson <cph@chris-hanson.org>
> >
> > Where did you find out about W^X ?
> >
> > I have an x86-64 machine running macos 11.2 and scheme works fine there,
> > mostly. Specifically, if I build the normal binaries, they seem to run
> > just fine. However, if I build a macos app, it fails to run at all.
> > Perhaps the W^X restriction applies only to apps?
> https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon
>
>     When memory protection is enabled, a thread cannot write to a
>     memory region and execute instructions in that region at the same
>     time. Apple silicon enables memory protection for all apps,
>     regardless of whether they adopt the Hardened Runtime. Intel-based
>     Mac computers enable memory protection only for apps that adopt the
>     Hardened Runtime.