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From:   Lance Roy <ldr709@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     "Paul E. McKenney" <paulmck@linux.ibm.com>,
        Lance Roy <ldr709@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Darren Hart <dvhart@infradead.org>
Subject: [PATCH 11/16] futex: Replace spin_is_locked() with lockdep
Date:   Tue,  2 Oct 2018 22:38:57 -0700
Message-Id: <20181003053902.6910-12-ldr709@gmail.com>
In-Reply-To: <20181003053902.6910-1-ldr709@gmail.com>
References: <20181003053902.6910-1-ldr709@gmail.com>
Reply-To: Lance Roy <ldr709@gmail.com>
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lockdep_assert_held() is better suited to checking locking requirements,
since it won't get confused when someone else holds the lock. This is
also a step towards possibly removing spin_is_locked().

Signed-off-by: Lance Roy <ldr709@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
---
 kernel/futex.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 11fc3bb456d6..3e2de8fc1891 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1365,9 +1365,9 @@ static void __unqueue_futex(struct futex_q *q)
 {
 	struct futex_hash_bucket *hb;
 
-	if (WARN_ON_SMP(!q->lock_ptr || !spin_is_locked(q->lock_ptr))
-	    || WARN_ON(plist_node_empty(&q->list)))
+	if (WARN_ON_SMP(!q->lock_ptr) || WARN_ON(plist_node_empty(&q->list)))
 		return;
+	lockdep_assert_held(q->lock_ptr);
 
 	hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock);
 	plist_del(&q->list, &hb->chain);
-- 
2.19.0