Re: [PATCH v7 09/11] arm64: disable SCS for hypervisor code

Will Deacon
2020-02-10T16:44:56Z

On Tue, Jan 28, 2020 at 10:49:32AM -0800, Sami Tolvanen wrote:
> Filter out CC_FLAGS_SCS and -ffixed-x18 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..5843adef9ef6 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 -ffixed-x18 $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))

Acked-by: Will Deacon <will@kernel.org>

Will