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

Will Deacon
2020-01-16T17:48:07Z

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?

Will