diff mbox series

kbuild: add -fcf-protection=none to retpoline flags

Message ID 20190709184919.20178-1-seth.forshee@canonical.com (mailing list archive)
State New, archived
Headers show
Series kbuild: add -fcf-protection=none to retpoline flags | expand

Commit Message

Seth Forshee July 9, 2019, 6:49 p.m. UTC 
-mindirect-branch and -fcf-protection are not compatible, and
so kernel builds fail with a gcc build where -fcf-protection is
enabled by default. Add -fcf-protection=none to the retpoline
flags to fix this.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
---
 Makefile | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Masahiro Yamada July 15, 2019, 12:21 p.m. UTC | #1 
On Wed, Jul 10, 2019 at 3:49 AM Seth Forshee <seth.forshee@canonical.com> wrote:
>
> -mindirect-branch and -fcf-protection are not compatible, and
> so kernel builds fail with a gcc build where -fcf-protection is
> enabled by default. Add -fcf-protection=none to the retpoline
> flags to fix this.
>
> Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
> ---

Applied to linux-kbuild. Thanks.



>  Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index 3e4868a6498b..050f11d19777 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -636,6 +636,10 @@ RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
>  RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
>  RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
>  RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
> +# -mindirect-branch is incompatible with -fcf-protection, so ensure the
> +# latter is disabled
> +RETPOLINE_CFLAGS += $(call cc-option,-fcf-protection=none,)
> +RETPOLINE_VDSO_CFLAGS += $(call cc-option,-fcf-protection=none,)
>  export RETPOLINE_CFLAGS
>  export RETPOLINE_VDSO_CFLAGS
>
> --
> 2.20.1
>
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 3e4868a6498b..050f11d19777 100644
--- a/Makefile
+++ b/Makefile
@@ -636,6 +636,10 @@  RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
+# -mindirect-branch is incompatible with -fcf-protection, so ensure the
+# latter is disabled
+RETPOLINE_CFLAGS += $(call cc-option,-fcf-protection=none,)
+RETPOLINE_VDSO_CFLAGS += $(call cc-option,-fcf-protection=none,)
 export RETPOLINE_CFLAGS
 export RETPOLINE_VDSO_CFLAGS