Re: [PATCH v6 13/15] arm64: disable SCS for hypervisor code

Sami Tolvanen
2020-01-16T20:17:25Z

On Thu, Jan 16, 2020 at 9:47 AM Will Deacon <will@kernel.org> wrote:
>
> On Fri, Dec 06, 2019 at 02:13:49PM -0800, Sami Tolvanen wrote:
> > Filter out CC_FLAGS_SCS for code that runs at a different exception
> > level.
> >
> > Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > Reviewed-by: Mark Rutland <mark.rutland@arm.com>
> > ---
> > arch/arm64/kvm/hyp/Makefile | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
> > index ea710f674cb6..17ea3da325e9 100644
> > --- a/arch/arm64/kvm/hyp/Makefile
> > +++ b/arch/arm64/kvm/hyp/Makefile
> > @@ -28,3 +28,6 @@ GCOV_PROFILE := n
> > KASAN_SANITIZE := n
> > UBSAN_SANITIZE := n
> > KCOV_INSTRUMENT := n
> > +
> > +# remove the SCS flags from all objects in this directory
> > +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
>
> Same comment as for the vDSO; can we remove the -ffixed-x18 as well?

Sure, I don't see why not. I'll change this in the next version.

Sami