Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[sfrench/cifs-2.6.git] / arch / x86 / Makefile

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 3e73bc255e4eb3edda965a6bc493e0e6ab8de354..fad55160dcb94a28e60d537d3d69d471a1e10e2e 100644 (file)
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -230,6 +230,14 @@ KBUILD_CFLAGS += -Wno-sign-compare
 #
 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 
+# Avoid indirect branches in kernel to deal with Spectre
+ifdef CONFIG_RETPOLINE
+    RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
+    ifneq ($(RETPOLINE_CFLAGS),)
+        KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -DRETPOLINE
+    endif
+endif
+
 archscripts: scripts_basic
        $(Q)$(MAKE) $(build)=arch/x86/tools relocs