[tip:core/rcu] locking/mutex: Replace spin_is_locked() with lockdep

[tip-bot for Lance Roy <tipbot@xxxxxxxxx>]

Commit-ID:  04547728b7b775333a4f6fbb3c55102a79dc4596
Gitweb:     https://git.kernel.org/tip/04547728b7b775333a4f6fbb3c55102a79dc4596
Author:     Lance Roy <ldr709@xxxxxxxxx>
AuthorDate: Thu, 4 Oct 2018 23:45:46 -0700
Committer:  Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
CommitDate: Mon, 12 Nov 2018 09:06:22 -0800

locking/mutex: Replace spin_is_locked() with lockdep

lockdep_assert_held() is better suited to checking locking requirements,
since it only checks if the current thread holds the lock regardless of
whether someone else does. This is also a step towards possibly removing
spin_is_locked().

Signed-off-by: Lance Roy <ldr709@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
---
 kernel/locking/mutex-debug.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index 9aa713629387..771d4ca96dda 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -36,7 +36,7 @@ void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
 
 void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
 {
-	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
+	lockdep_assert_held(&lock->wait_lock);
 	DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
 	DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
 	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
@@ -51,7 +51,7 @@ void debug_mutex_free_waiter(struct mutex_waiter *waiter)
 void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 			    struct task_struct *task)
 {
-	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
+	lockdep_assert_held(&lock->wait_lock);
 
 	/* Mark the current thread as blocked on the lock: */
 	task->blocked_on = waiter;