lkml.org 
[lkml]   [2018]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] include/linux/mmdebug.h: make VM_WARN* non-rvals
Date
At present the construct

if (VM_WARN(...))

will compile OK with CONFIG_DEBUG_VM=y and will fail with
CONFIG_DEBUG_VM=n. The reason is that VM_{WARN,BUG}* have always been
special wrt. {WARN/BUG}* and never generate any code when DEBUG_VM is
disabled. So we cannot really use it in conditionals.

We considered changing things so that this construct works in both cases
but that might cause unwanted code generation with CONFIG_DEBUG_VM=n. It
is safer and simpler to make the build fail in both cases.

Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
[akpm@linux-foundation.org: changelog]
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mmdebug.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 35d77b0dae3b..14baf1d9d65b 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -37,10 +37,10 @@ void dump_mm(const struct mm_struct *mm);
BUG(); \
} \
} while (0)
-#define VM_WARN_ON(cond) WARN_ON(cond)
-#define VM_WARN_ON_ONCE(cond) WARN_ON_ONCE(cond)
-#define VM_WARN_ONCE(cond, format...) WARN_ONCE(cond, format)
-#define VM_WARN(cond, format...) WARN(cond, format)
+#define VM_WARN_ON(cond) (void)WARN_ON(cond)
+#define VM_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)
+#define VM_WARN_ONCE(cond, format...) (void)WARN_ONCE(cond, format)
+#define VM_WARN(cond, format...) (void)WARN(cond, format)
#else
#define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
#define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond)
--
2.16.1
\
 
 \ /
  Last update: 2018-03-19 08:58    [W:0.027 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site