2018-09-11 12:21:24

by Igor Stoppa

[permalink] [raw]
Subject: [PATCH v2] asm-generic: bug: unify hints for BUG_ON()

If BUG_ON() is used instead of BUG(), it means that probably the
preferred outcome is to not BUG(), therefore the condition tested should
be unlikely().

However, when CONFIG_PROFILE_ANNOTATED_BRANCHES is enabled, the hint is
disabled, to avoid generating false-positive warnings caused by
-Wmaybe-uninitialized.

Signed-off-by: Igor Stoppa <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
include/asm-generic/bug.h | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 20561a60db9c..b91273c36baf 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -58,8 +58,12 @@ struct bug_entry {
#endif

#ifndef HAVE_ARCH_BUG_ON
+#ifdef CONFIG_PROFILE_ANNOTATED_BRANCHES
+#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
+#else
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
#endif
+#endif

#ifdef __WARN_FLAGS
#define __WARN_TAINT(taint) __WARN_FLAGS(BUGFLAG_TAINT(taint))
@@ -183,7 +187,11 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
#endif

#ifndef HAVE_ARCH_BUG_ON
+#ifdef CONFIG_PROFILE_ANNOTATED_BRANCHES
#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
+#else
+#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
+#endif
#endif

#ifndef HAVE_ARCH_WARN_ON
--
2.17.1