summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJosh Poimboeuf <jpoimboe@redhat.com>2017-07-24 23:34:14 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-06-13 14:16:44 (GMT)
commit23873aedff967436b59e478d75ca3317e4f0dfc5 (patch)
tree5e918916ee09108700f69d731c641408fa910cd9
parente1fba17e26f08a142b4cdf5c74a2113e7f895daa (diff)
objtool: Fix gcov check for older versions of GCC
commit 867ac9d737094e46a6c33213f16dd1ec9e8bd5d5 upstream. Objtool tries to silence 'unreachable instruction' warnings when it detects gcov is enabled, because gcov produces a lot of unreachable instructions and they don't really matter. However, the 0-day bot is still reporting some unreachable instruction warnings with CONFIG_GCOV_KERNEL=y on GCC 4.6.4. As it turns out, objtool's gcov detection doesn't work with older versions of GCC because they don't create a bunch of symbols with the 'gcov.' prefix like newer versions of GCC do. Move the gcov check out of objtool and instead just create a new '--no-unreachable' flag which can be passed in by the kernel Makefile when CONFIG_GCOV_KERNEL is defined. Also rename the 'nofp' variable to 'no_fp' for consistency with the new 'no_unreachable' variable. 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> Fixes: 9cfffb116887 ("objtool: Skip all "unreachable instruction" warnings for gcov kernels") Link: http://lkml.kernel.org/r/c243dc78eb2ffdabb6e927844dea39b6033cd395.1500939244.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> [just Makefile.build as the other parts of this patch already applied - gregkh] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--scripts/Makefile.build3
1 files changed, 3 insertions, 0 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 7675d11..abfd4f4 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -253,6 +253,9 @@ objtool_args = check
ifndef CONFIG_FRAME_POINTER
objtool_args += --no-fp
endif
+ifdef CONFIG_GCOV_KERNEL
+objtool_args += --no-unreachable
+endif
# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file