Re: [PATCH v4 11/17] arm64: disable function graph tracing with SCS

[Sami Tolvanen]

On Mon, Nov 4, 2019 at 9:11 AM Mark Rutland <mark.rutland@xxxxxxx> wrote:
> Can you please elaborate on _how_ this is incompatible in the commit
> message?
>
> For example, it's not clear to me if you mean that's functionally
> incompatible, or if you're trying to remove return-altering gadgets.
>
> If there's a functional incompatibility, please spell that out a bit
> more clearly. Likewise if this is about minimizing the set of places
> that can mess with control-flow outside of usual function conventions.

Sure, I'll add a better description in v5. In this case, the return
address is modified in the kernel stack, which means the changes are
ignored with SCS.

Sami