Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 44/44] x86/build: Fix compiler support check for CONFIG_RETPOLINE | Date | Tue, 18 Dec 2018 17:39:56 +0100 |
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4.19-stable review patch. If anyone has any objections, please let me know.
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From: Masahiro Yamada <yamada.masahiro@socionext.com>
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 <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> 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 <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Cc: Gi-Oh Kim <gi-oh.kim@cloud.ionos.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/Makefile | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -223,9 +223,6 @@ 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 += $(RETPOLINE_CFLAGS) endif @@ -303,6 +300,13 @@ ifndef CC_HAVE_ASM_GOTO @echo Compiler lacks asm-goto support. @exit 1 endif +ifdef CONFIG_RETPOLINE +ifeq ($(RETPOLINE_CFLAGS),) + @echo "You are building kernel with non-retpoline compiler." >&2 + @echo "Please update your compiler." >&2 + @false +endif +endif archclean: $(Q)rm -rf $(objtree)/arch/i386
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