[PATCH] lockdep: add a hint for "INFO: trying to register non-static key." message

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	linux-kernel@vger.kernel.org,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: [PATCH] lockdep: add a hint for "INFO: trying to register non-static key." message
Date: Sun, 21 Mar 2021 15:49:13 +0900	[thread overview]
Message-ID: <20210321064913.4619-1-penguin-kernel@I-love.SAKURA.ne.jp> (raw)

Since this message is printed when dynamically allocated spinlocks (e.g.
kzalloc()) are used without initialization (e.g. spin_lock_init()),
suggest developers to check whether initialization functions for objects
are called, before making developers wonder what annotation is missing.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
 kernel/locking/lockdep.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index c6d0c1dc6253..44c549f5c061 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -931,6 +931,7 @@ static bool assign_lock_key(struct lockdep_map *lock)
 		debug_locks_off();
 		pr_err("INFO: trying to register non-static key.\n");
 		pr_err("the code is fine but needs lockdep annotation.\n");
+		pr_err("maybe you didn't initialize this object before you use?\n");
 		pr_err("turning off the locking correctness validator.\n");
 		dump_stack();
 		return false;
-- 
2.18.4

