First problem: I cannot compile the kernel with my version of compiler
~~~~ $ make defconfig *** Default configuration is based on 'i386_defconfig' # # configuration written to .config # $ grep CONFIG_RETPOLINE .config CONFIG_RETPOLINE=y $ make arch/x86/Makefile:224: *** You are building kernel with non-retpoline compiler, please update your compiler.. Stop. ~~~~
Second problem: when I disable the feature - it cannot take effect, because the parse-time error happens before `syncconfig`
~~~~ $ scripts/config -d RETPOLINE $ grep CONFIG_RETPOLINE .config # CONFIG_RETPOLINE is not set $ make arch/x86/Makefile:224: *** You are building kernel with non-retpoline compiler, please update your compiler.. Stop. ~~~~
Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Signed-off-by: Kirill Marinushkin k.marinushkin@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Ingo Molnar mingo@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: Zhenzhong Duan zhenzhong.duan@oracle.com Cc: H. Peter Anvin hpa@zytor.com Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org --- arch/x86/Makefile | 3 --- 1 file changed, 3 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index f5d7f4134524..26a2198c59b3 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -220,9 +220,6 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
# 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