linux-kernel - [PATCH] objtool: enclose contents of unreachable() macro in a block

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: <20170228042116.glmwmwiohcix7o4a@treble>
Date:   Mon, 27 Feb 2017 22:21:16 -0600
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Guenter Roeck <linux@...ck-us.net>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>, linux-kernel@...r.kernel.org
Subject: [PATCH] objtool: enclose contents of unreachable() macro in a block


Guenter Roeck reported a boot failure in mips64.  It was bisected to the
following commit:

  d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")

The unreachable() macro was formerly only composed of a single
statement.  The above commit added a second statement, but neglected to
enclose the statements in a block.

Reported-by: Guenter Roeck <linux@...ck-us.net>
Suggested-by: Guenter Roeck <linux@...ck-us.net>
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
Signed-off-by: Josh Poimboeuf <jpoimboe@...hat.com>
---
 include/linux/compiler-gcc.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index de47134..f457b520 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -215,7 +215,8 @@
  * this in the preprocessor, but we can live with this because they're
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
-#define unreachable() annotate_unreachable(); __builtin_unreachable()
+#define unreachable() \
+	do { annotate_unreachable(); __builtin_unreachable(); } while (0)
 
 /* Mark a function definition as prohibited from being cloned. */
 #define __noclone	__attribute__((__noclone__, __optimize__("no-tracer")))
-- 
2.7.4