linux-kernel - [RFC PATCH v3 1/4] objtool: allow nested externs to enable BUILD

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

Message-ID: <patch-1.thread-6ec90b.git-71a9d5e14a6c.your-ad-here.call-01601502173-ext-7769@work.hours>
Date:   Thu, 1 Oct 2020 00:17:22 +0200
From:   Vasily Gorbik <gor@...ux.ibm.com>
To:     Josh Poimboeuf <jpoimboe@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     Masami Hiramatsu <mhiramat@...nel.org>,
        David Laight <David.Laight@...lab.com>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>,
        Miroslav Benes <mbenes@...e.cz>,
        Alexandre Chartre <alexandre.chartre@...cle.com>,
        Julien Thierry <jthierry@...hat.com>,
        linux-kernel@...r.kernel.org
Subject: [RFC PATCH v3 1/4] objtool: allow nested externs to enable
 BUILD_BUG()

Currently BUILD_BUG() macro is expanded to smth like the following:
   do {
           extern void __compiletime_assert_0(void)
                   __attribute__((error("BUILD_BUG failed")));
           if (!(!(1)))
                   __compiletime_assert_0();
   } while (0);

If used in a function body this obviously would produce build errors
with -Wnested-externs and -Werror.

Build objtool with -Wno-nested-externs to enable BUILD_BUG() usage.

Signed-off-by: Vasily Gorbik <gor@...ux.ibm.com>
---
 tools/objtool/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 33d1e3ca8efd..4ea9a833dde7 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -37,7 +37,7 @@ INCLUDES := -I$(srctree)/tools/include \
 	    -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
 	    -I$(srctree)/tools/arch/$(SRCARCH)/include	\
 	    -I$(srctree)/tools/objtool/arch/$(SRCARCH)/include
-WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed
+WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed -Wno-nested-externs
 CFLAGS   := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
 LDFLAGS  += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
 
-- 
⣿⣿⣿⣿⢋⡀⣀⠹⣿⣿⣿⣿
⣿⣿⣿⣿⠠⣶⡦⠀⣿⣿⣿⣿
⣿⣿⣿⠏⣴⣮⣴⣧⠈⢿⣿⣿
⣿⣿⡏⢰⣿⠖⣠⣿⡆⠈⣿⣿
⣿⢛⣵⣄⠙⣶⣶⡟⣅⣠⠹⣿
⣿⣜⣛⠻⢎⣉⣉⣀⠿⣫⣵⣿