This patch allows compilation to succeed with compilers that support 
-DRETPOLINE -
         it was kindly contributed by H.J. Liu in GCC Bugzilla: 84908 :
            https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84908

         Apparently the GCC retpoline implementation has a limitation that it 
cannot
         handle switch statements with more than 5 clauses, which 
vclock_gettime.c's
         __vdso_clock_gettime function now contains.

         The automated test builds should now succeed with this patch.


diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 1943aeb..cb64e10 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -76,7 +76,7 @@ CFL := $(PROFILING) -mcmodel=small -fPIC -O2 
-fasynchronous-unwind-tables -m64 \
        -fno-omit-frame-pointer -foptimize-sibling-calls \
        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
 
-$(vobjs): KBUILD_CFLAGS := $(filter-out 
$(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) 
$(RETPOLINE_CFLAGS) -DRETPOLINE,$(KBUILD_CFLAGS)) $(CFL)
 
 #
 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
@@ -143,6 +143,7 @@ KBUILD_CFLAGS_32 := $(filter-out 
-mcmodel=kernel,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS) 
-DRETPOLINE,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)

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