[S390] vdso: disable gcov profiling

The concepts of VDSO and gcov-based profiling don't mix: the former
includes kernel-provided code running in userspace, the latter adds
instructions that modify counters in kernel data segments. On s390
this has not been a problem so far due to VDSO code being written in
all-assembler which is exempt from gcov-based profiling. This could
change in the future, so disable profiling excplicitly for VDSO code.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/vdso32/Makefile

@@ -22,6 +22,9 @@ obj-y += vdso32_wrapper.o
 extra-y += vdso32.lds
 CPPFLAGS_vdso32.lds += -P -C -U$(ARCH)
 
+# Disable gcov profiling for VDSO code
+GCOV_PROFILE := n
+
 # Force dependency (incbin is bad)
 $(obj)/vdso32_wrapper.o : $(obj)/vdso32.so
 

arch/s390/kernel/vdso64/Makefile

@@ -22,6 +22,9 @@ obj-y += vdso64_wrapper.o
 extra-y += vdso64.lds
 CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
 
+# Disable gcov profiling for VDSO code
+GCOV_PROFILE := n
+
 # Force dependency (incbin is bad)
 $(obj)/vdso64_wrapper.o : $(obj)/vdso64.so