Messages in this thread Patch in this message | | | Date | Fri, 19 Nov 2021 17:50:25 +0100 | From | Peter Zijlstra <> | Subject | [PATCH 2/3] x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds |
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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) <peterz@infradead.org> Acked-by: Nick Desaulniers <ndesaulniers@google.com> --- arch/x86/Makefile | 1 + 1 file changed, 1 insertion(+)
--- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -14,6 +14,7 @@ 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
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