linux-kernel - [PATCH] objtool: Skip unreachable warnings for GCC 4.4 and older

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 27 Sep 2017 17:34:23 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH] objtool: Skip unreachable warnings for GCC 4.4 and older

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@...el.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@...hat.com>
---
 scripts/Makefile.build | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 2e3a10e79ca9..061d0c3a420a 100644
--- 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
-- 
2.13.5