[tip: perf/urgent] lockdep: Add a missing initialization hint to the "INFO: Trying to register non-static key" message

[tip-bot2 for Tetsuo Handa]

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     3a85969e9d912d5dd85362ee37b5f81266e00e77
Gitweb:        https://git.kernel.org/tip/3a85969e9d912d5dd85362ee37b5f81266e00e77
Author:        Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
AuthorDate:    Sun, 21 Mar 2021 15:49:13 +09:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sun, 21 Mar 2021 11:59:57 +01:00

lockdep: Add a missing initialization hint to the "INFO: Trying to register non-static key" message

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

[ mingo: Minor tweaks to the message. ]

Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210321064913.4619-1-penguin-kernel@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 kernel/locking/lockdep.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index c6d0c1d..c30eb88 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -930,7 +930,8 @@ static bool assign_lock_key(struct lockdep_map *lock)
 		/* Debug-check: all keys must be persistent! */
 		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("The code is fine but needs lockdep annotation, or maybe\n");
+		pr_err("you didn't initialize this object before use?\n");
 		pr_err("turning off the locking correctness validator.\n");
 		dump_stack();
 		return false;