From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
keescook@chromium.org, hjl.tools@gmail.com,
andrew.cooper3@citrix.com, mark.rutland@arm.com, will@kernel.org,
ndesaulniers@google.com
Subject: [PATCH 2/3] x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds
Date: Fri, 19 Nov 2021 17:50:25 +0100 [thread overview]
Message-ID: <20211119165630.276205624@infradead.org> (raw)
In-Reply-To: 20211119165023.249607540@infradead.org
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
next prev parent reply other threads:[~2021-11-19 16:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-19 16:50 [PATCH 0/3] x86: Add GCC-12 features Peter Zijlstra
2021-11-19 16:50 ` [PATCH 1/3] x86: Move RETPOLINE*_CFLAGS to arch Makefile Peter Zijlstra
2021-11-19 17:10 ` Kees Cook
2021-11-19 19:02 ` Nick Desaulniers
2021-12-10 11:05 ` [tip: x86/core] " tip-bot2 for Peter Zijlstra
2021-11-19 16:50 ` Peter Zijlstra [this message]
2021-11-19 17:10 ` [PATCH 2/3] x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds Kees Cook
2021-12-10 11:05 ` [tip: x86/core] " tip-bot2 for Peter Zijlstra
2021-11-19 16:50 ` [PATCH 3/3] x86: Add straight-line-speculation mitigation Peter Zijlstra
2021-11-19 17:15 ` Kees Cook
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