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From:   Yuyang Du <duyuyang@gmail.com>
To:     peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org
Cc:     bvanassche@acm.org, ming.lei@redhat.com, frederic@kernel.org,
        tglx@linutronix.de, linux-kernel@vger.kernel.org,
        longman@redhat.com, paulmck@linux.vnet.ibm.com,
        boqun.feng@gmail.com, Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH v4 25/30] locking/lockdep: Introduce mark_lock_unaccessed()
Date:   Thu, 29 Aug 2019 16:31:27 +0800
Message-Id: <20190829083132.22394-26-duyuyang@gmail.com>
In-Reply-To: <20190829083132.22394-1-duyuyang@gmail.com>
References: <20190829083132.22394-1-duyuyang@gmail.com>
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Since in the graph search, multiple matches may be needed, a matched lock
needs to rejoin the search for another match, thereby introduce
mark_lock_unaccessed().

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
 kernel/locking/lockdep.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 05c70be..4cd844e 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1521,6 +1521,15 @@ static inline void mark_lock_accessed(struct lock_list *lock,
 	lock->class[forward]->dep_gen_id = lockdep_dependency_gen_id;
 }
 
+static inline void mark_lock_unaccessed(struct lock_list *lock)
+{
+	unsigned long nr;
+
+	nr = lock - list_entries;
+	WARN_ON(nr >= ARRAY_SIZE(list_entries)); /* Out-of-bounds, input fail */
+	fw_dep_class(lock)->dep_gen_id--;
+}
+
 static inline unsigned long lock_accessed(struct lock_list *lock, int forward)
 {
 	unsigned long nr;
-- 
1.8.3.1