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 <20191024225132.13410-1-samitolvanen@google.com> <20191024225132.13410-17-samitolvanen@google.com>
In-Reply-To: <20191024225132.13410-17-samitolvanen@google.com>
From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Fri, 25 Oct 2019 10:29:47 +0900
Message-ID: <CAK7LNATPpL-B0APPXFcWPCR6ZTSrXv-v_ZkdFqjKJ4pwUpcWug@mail.gmail.com>
Subject: Re: [PATCH v2 16/17] arm64: disable SCS for hypervisor code
To:     Sami Tolvanen <samitolvanen@google.com>
Cc:     Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Dave Martin <Dave.Martin@arm.com>,
        Kees Cook <keescook@chromium.org>,
        Laura Abbott <labbott@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Jann Horn <jannh@google.com>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Kernel Hardening <kernel-hardening@lists.openwall.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Fri, Oct 25, 2019 at 7:52 AM <samitolvanen@google.com> wrote:
>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.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..8289ea086e5e 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
> +
> +ORIG_CFLAGS := $(KBUILD_CFLAGS)
> +KBUILD_CFLAGS = $(subst $(CC_FLAGS_SCS),,$(ORIG_CFLAGS))


$(subst ... ) is not the correct use here.

It works like sed,   s/$(CC_CFLAGS_SCS)//
instead of matching by word.


KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))

is more correct, and simpler.


-- 
Best Regards
Masahiro Yamada