[PATCH RESEND] x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block

From: Nathan Chancellor
Date: Fri Jan 20 2023 - 12:00:57 EST


LLVM 16 will have support for this flag so move it out of the GCC-only
block to allow LLVM builds to take advantage of it.

Link: https://github.com/ClangBuiltLinux/linux/issues/1665
Link: https://github.com/llvm/llvm-project/commit/6f867f9102838ebe314c1f3661fdf95700386e5a
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---

I picked up the tags on the previous patch but otherwise, this is
indentical to the original posting:

https://lore.kernel.org/20220817185410.1174782-1-nathan@xxxxxxxxxx/

arch/x86/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 9cf07322875a..73ed982d4100 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -14,13 +14,13 @@ endif

ifdef CONFIG_CC_IS_GCC
RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
-RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix)
RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
endif
ifdef CONFIG_CC_IS_CLANG
RETPOLINE_CFLAGS := -mretpoline-external-thunk
RETPOLINE_VDSO_CFLAGS := -mretpoline
endif
+RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix)

ifdef CONFIG_RETHUNK
RETHUNK_CFLAGS := -mfunction-return=thunk-extern

base-commit: 5dc4c995db9eb45f6373a956eb1f69460e69e6d4
--
2.39.1