From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Meelis Roos , Masahiro Yamada , Zhenzhong Duan , Borislav Petkov , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Sasha Levin , Gi-Oh Kim Subject: [PATCH 4.14 19/72] x86/build: Fix compiler support check for CONFIG_RETPOLINE Date: Thu, 20 Dec 2018 10:18:18 +0100 Message-Id: <20181220085923.092006934@linuxfoundation.org> In-Reply-To: <20181220085922.332225035@linuxfoundation.org> References: <20181220085922.332225035@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masahiro Yamada commit 25896d073d8a0403b07e6dec56f58e6c33678207 upstream. It is troublesome to add a diagnostic like this to the Makefile parse stage because the top-level Makefile could be parsed with a stale include/config/auto.conf. Once you are hit by the error about non-retpoline compiler, the compilation still breaks even after disabling CONFIG_RETPOLINE. The easiest fix is to move this check to the "archprepare" like this commit did: 829fe4aa9ac1 ("x86: Allow generating user-space headers without a compiler") Reported-by: Meelis Roos Tested-by: Meelis Roos Signed-off-by: Masahiro Yamada Acked-by: Zhenzhong Duan Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Zhenzhong Duan Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") Link: http://lkml.kernel.org/r/1543991239-18476-1-git-send-email-yamada.masahiro@socionext.com Link: https://lkml.org/lkml/2018/12/4/206 Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Cc: Gi-Oh Kim Signed-off-by: Greg Kroah-Hartman --- arch/x86/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -241,9 +241,6 @@ KBUILD_CFLAGS += -fno-asynchronous-unwin # Avoid indirect branches in kernel to deal with Spectre ifdef CONFIG_RETPOLINE -ifeq ($(RETPOLINE_CFLAGS),) - $(error You are building kernel with non-retpoline compiler, please update your compiler.) -endif KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) endif @@ -260,6 +257,13 @@ archprepare: ifeq ($(CONFIG_KEXEC_FILE),y) $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c endif +ifdef CONFIG_RETPOLINE +ifeq ($(RETPOLINE_CFLAGS),) + @echo "You are building kernel with non-retpoline compiler." >&2 + @echo "Please update your compiler." >&2 + @false +endif +endif ### # Kernel objects