Re: [PATCH] x86/vsyscall: Remove CONFIG_LEGACY_VSYSCALL_EMULATE

[Florian Weimer <fweimer@redhat.com>]

* Andy Lutomirski:

> CONFIG_LEGACY_VSYSCALL_EMULATE is, as far as I know, only needed for the
> combined use of exotic and outdated debugging mechanisms with outdated
> binaries.  At this point, no one should be using it.  We would like to
> implement dynamic switching of vsyscalls, but this is much more
> complicated to support in EMULATE mode than XONLY mode.
>
> So let's force all the distros off of EMULATE mode.  If anyone actually
> needs it, they can set vsyscall=emulate, and we can then get away with
> refusing to support newer security models if that option is set.
>
> Cc: x86@kernel.org
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Florian Weimer <fweimer@redhat.com>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Sounds a good idea to me.

Acked-by: Florian Weimer <fweimer@redhat.com>

Regarding the mechanics, is it customary to remove the actual code (the
EMULATE enum constant) in later commits?

Thanks,
Florian