From b4296a7b863f201f9be08fee6f8891f4912de011 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 19 Nov 2021 17:50:25 +0100 Subject: [PATCH] x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds commit 68cf4f2a72ef8786e6b7af6fd9a89f27ac0f520d upstream. In order to further enable commit: bbe2df3f6b6d ("x86/alternative: Try inline spectre_v2=retpoline,amd") add the new GCC flag -mindirect-branch-cs-prefix: https://gcc.gnu.org/g:2196a681d7810ad8b227bf983f38ba716620545e https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952 https://bugs.llvm.org/show_bug.cgi?id=52323 to RETPOLINE=y builds. This should allow fully inlining retpoline,amd for GCC builds. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Kees Cook Acked-by: Nick Desaulniers Link: https://lkml.kernel.org/r/20211119165630.276205624@infradead.org Signed-off-by: Greg Kroah-Hartman --- Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/Makefile b/Makefile index e386484..2c6eb13 100644 --- a/Makefile +++ b/Makefile @@ -687,6 +687,7 @@ 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 -- 2.7.4