[PATCH v1] x86/vdso: fix CE on non-compatible cflags

From: Tong Zhang
Date: Tue Feb 09 2021 - 20:56:37 EST


I am getting some compilation error on when using CONFIG_X86_32 kernel
configuration

arch/x86/entry/vdso/vdso32/../vclock_gettime.c:29:1:
error: ‘-mindirect-branch’ and ‘-fcf-protection’ are not compatible

add -fcf-protection=none when CONFIG_RETPOLINE=y

Signed-off-by: Tong Zhang <ztong0001@xxxxxxxxx>
---
arch/x86/entry/vdso/Makefile | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 02e3e42f380b..37885336b53f 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -159,6 +159,7 @@ KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
ifdef CONFIG_RETPOLINE
ifneq ($(RETPOLINE_VDSO_CFLAGS),)
KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
+ KBUILD_CFLAGS_32 += $(call cc-option,-fcf-protection=none)
endif
endif

--
2.25.1