s390: enable kcov support

Now that hopefully all inline assemblies have been converted to single
basic blocks we can enable kcov on s390.

Note that this patch does not disable as many files on s390 like the
x86 variant does. Right now I didn't see a reason to do that, however
additional files or directories can be excluded at any time.

The runtime overhead seems to be quite high.

Signed-off-by: Heiko Carstens <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

arch/s390/Kconfig

···
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_KCOV
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK

arch/s390/boot/compressed/Makefile

···
 # create a compressed vmlinux image from the original vmlinux
 #
 
+KCOV_INSTRUMENT := n
+
 targets	:= vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2
 targets += vmlinux.bin.xz vmlinux.bin.lzma vmlinux.bin.lzo vmlinux.bin.lz4
 targets += misc.o piggy.o sizes.h head.o

arch/s390/kernel/Makefile

···
 # Makefile for the linux kernel.
 #
 
+KCOV_INSTRUMENT_early.o := n
+KCOV_INSTRUMENT_sclp.o := n
+
 ifdef CONFIG_FUNCTION_TRACER
 # Don't trace early setup code and tracing code
 CFLAGS_REMOVE_early.o = $(CC_FLAGS_FTRACE)

arch/s390/kernel/vdso32/Makefile

···
 # List of files in the vdso, has to be asm only for now
 
+KCOV_INSTRUMENT := n
+
 obj-vdso32 = gettimeofday.o clock_getres.o clock_gettime.o note.o getcpu.o
 
 # Build rules

arch/s390/kernel/vdso64/Makefile

···
 # List of files in the vdso, has to be asm only for now
 
+KCOV_INSTRUMENT := n
+
 obj-vdso64 = gettimeofday.o clock_getres.o clock_gettime.o note.o getcpu.o
 
 # Build rules