[PATCH 3.2 111/126] lockdep: Silence warning if CONFIG_LOCKDEP isn't set

From: Ben Hutchings
Date: Wed Feb 15 2017 - 18:35:54 EST

3.2.85-rc1 review patch. If anyone has any objections, please let me know.


From: Paul Bolle <pebolle@xxxxxxxxxx>

commit 5cd3f5affad2109fd1458aab3f6216f2181e26ea upstream.

Since commit c9a4962881929df7f1ef6e63e1b9da304faca4dd ("nfsd:
make client_lock per net") compiling nfs4state.o without
CONFIG_LOCKDEP set, triggers this GCC warning:

fs/nfsd/nfs4state.c: In function âfree_clientâ:
fs/nfsd/nfs4state.c:1051:19: warning: unused variable ânnâ [-Wunused-variable]

The cause of that warning is that lockdep_assert_held() compiles
away if CONFIG_LOCKDEP is not set. Silence this warning by using
the argument to lockdep_assert_held() as a nop if CONFIG_LOCKDEP
is not set.

Signed-off-by: Paul Bolle <pebolle@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
Cc: J. Bruce Fields <bfields@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1359060797.1325.33.camel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
include/linux/lockdep.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -394,7 +394,7 @@ struct lock_class_key { };

#define lockdep_depth(tsk) (0)

-#define lockdep_assert_held(l) do { } while (0)
+#define lockdep_assert_held(l) do { (void)(l); } while (0)
#define lockdep_assert_held_once(l) do { (void)(l); } while (0)

#endif /* !LOCKDEP */