objtool: Skip unreachable warnings for GCC 4.4 and older

jpoimboe · Ingo Molnar · commit da541b20021c · 2017-09-28T07:23:02.000+02:00
The kbuild bot occasionally reports warnings like: drivers/scsi/pcmcia/aha152x_core.o: warning: objtool: seldo_run()+0x130: unreachable instruction These warnings are always with GCC 4.4. That version of GCC sometimes places unreachable instructions after calls to noreturn functions. The unreachable warnings aren't very important anyway. Just ignore them for old versions of GCC. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/bc89b807d965b98ec18a0bb94f96a594bd58f2f2.1506551639.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
@@ -265,6 +265,8 @@ objtool_args += --no-fp
 endif
 ifdef CONFIG_GCOV_KERNEL
 objtool_args += --no-unreachable
+else
+objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
 endif
 
 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
