Messages in this thread Patch in this message | | | Date | Fri, 10 Dec 2021 11:05:19 -0000 | From | "tip-bot2 for Peter Zijlstra" <> | Subject | [tip: x86/core] x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds |
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The following commit has been merged into the x86/core branch of tip:
Commit-ID: 68cf4f2a72ef8786e6b7af6fd9a89f27ac0f520d Gitweb: https://git.kernel.org/tip/68cf4f2a72ef8786e6b7af6fd9a89f27ac0f520d Author: Peter Zijlstra <peterz@infradead.org> AuthorDate: Fri, 19 Nov 2021 17:50:25 +01:00 Committer: Borislav Petkov <bp@suse.de> CommitterDate: Wed, 08 Dec 2021 11:57:04 +01:00
x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds
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> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lkml.kernel.org/r/20211119165630.276205624@infradead.org --- arch/x86/Makefile | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 2f40de5..c38b657 100644 --- 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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