powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer

commit 6977f95e upstream.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[nc: Adjust context due to lack of f2910f0e and 2a056f58]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/powerpc/Makefile

@@ -236,7 +236,12 @@ endif
 
 # Work around a gcc code-gen bug with -fno-omit-frame-pointer.
 ifeq ($(CONFIG_FUNCTION_TRACER),y)
-KBUILD_CFLAGS		+= -mno-sched-epilog
+# Work around gcc code-gen bugs with -pg / -fno-omit-frame-pointer in gcc <= 4.8
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44199
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52828
+ifneq ($(cc-name),clang)
+KBUILD_CFLAGS		+= $(call cc-ifversion, -lt, 0409, -mno-sched-epilog)
+endif
 endif
 
 cpu-as-$(CONFIG_4xx)		+= -Wa,-m405