linux-kernel - [PATCH 11/11] Use unreachable() in asm-generic/bug.h for !CONFIG

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]

Date:	Mon, 14 Sep 2009 14:55:40 -0700
From:	David Daney <ddaney@...iumnetworks.com>
To:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	David Daney <ddaney@...iumnetworks.com>,
	Ingo Molnar <mingo@...e.hu>
Subject: [PATCH 11/11] Use unreachable() in asm-generic/bug.h for !CONFIG_BUG case.

The subject says it all (most).  The only drawback here is that for a
pre-GCC-5.4 compiler, instead of expanding to nothing we now expand
BUG() to an endless loop.  Before the patch when configured with
!CONFIG_BUG() you might get some warnings, but the code would be
small.  After the patch there are no warnings, but there is an endless
loop at each BUG() site.

Of course for the GCC-4.5 case we get the best of both worlds.

Signed-off-by: David Daney <ddaney@...iumnetworks.com>
Suggested-by: Ingo Molnar <mingo@...e.hu>
CC: Ingo Molnar <mingo@...e.hu>
---
 include/asm-generic/bug.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 4b67559..e952242 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -89,11 +89,11 @@ extern void warn_slowpath_null(const char *file, const int line);
 
 #else /* !CONFIG_BUG */
 #ifndef HAVE_ARCH_BUG
-#define BUG() do {} while(0)
+#define BUG() unreachable()
 #endif
 
 #ifndef HAVE_ARCH_BUG_ON
-#define BUG_ON(condition) do { if (condition) ; } while(0)
+#define BUG_ON(condition) do { if (condition) unreachable(); } while (0)
 #endif
 
 #ifndef HAVE_ARCH_WARN_ON
-- 
1.6.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/