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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, boqun.feng@gmail.com,
	linux-kernel@vger.kernel.org, Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH 03/17] locking/lockdep: Add helper functions to operate on the searched path
Date: Mon, 13 May 2019 17:11:49 +0800	[thread overview]
Message-ID: <20190513091203.7299-4-duyuyang@gmail.com> (raw)
In-Reply-To: <20190513091203.7299-1-duyuyang@gmail.com>

 - find_lock_in_path() tries to find whether a lock class is in the path.

 - find_next_dep_in_path() returns the next dependency after a
   given dependency in the path.

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
 kernel/locking/lockdep.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 4091002..0617375 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1365,6 +1365,37 @@ static inline int get_lock_depth(struct lock_list *child)
 }
 
 /*
+ * Return the dependency if @lock is in the path, otherwise NULL.
+ */
+static inline struct lock_list *
+find_lock_in_path(struct lock_class *lock, struct lock_list *target)
+{
+	while ((target = get_lock_parent(target)))
+		if (target->class == lock)
+			return target;
+
+	return NULL;
+}
+
+/*
+ * Walk back to the next dependency after @source from @target. Note
+ * that @source must be in the path, and @source can not be the same as
+ * @target, otherwise this is going to fail and reutrn NULL.
+ */
+static inline struct lock_list *
+find_next_dep_in_path(struct lock_list *source, struct lock_list *target)
+{
+	while (get_lock_parent(target) != source) {
+		target = get_lock_parent(target);
+
+		if (!target)
+			break;
+	}
+
+	return target;
+}
+
+/*
  * Return the forward or backward dependency list.
  *
  * @lock:   the lock_list to get its class's dependency list
-- 
1.8.3.1


  parent reply	other threads:[~2019-05-13  9:15 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-13  9:11 [PATCH 00/17] Support for read-write lock deadlock detection Yuyang Du
2019-05-13  9:11 ` [PATCH 01/17] locking/lockdep: Add lock type enum to explicitly specify read or write locks Yuyang Du
2019-05-13 11:45   ` Peter Zijlstra
2019-05-14  1:31     ` Yuyang Du
2019-05-14 12:04       ` Peter Zijlstra
2019-05-13  9:11 ` [PATCH 02/17] locking/lockdep: Add read-write type for dependency Yuyang Du
2019-05-13  9:11 ` Yuyang Du [this message]
2019-05-13  9:11 ` [PATCH 04/17] locking/lockdep: Update direct dependency's read-write type if it exists Yuyang Du
2019-05-13  9:11 ` [PATCH 05/17] locking/lockdep: Rename deadlock check functions Yuyang Du
2019-05-13  9:11 ` [PATCH 06/17] locking/lockdep: Adjust BFS algorithm to support multiple matches Yuyang Du
2019-05-13  9:11 ` [PATCH 07/17] locking/lockdep: Introduce mark_lock_unaccessed() Yuyang Du
2019-05-13  9:11 ` [PATCH 08/17] locking/lockdep: Introduce chain_hlocks_type for held lock's read-write type Yuyang Du
2019-05-13  9:11 ` [PATCH 09/17] locking/lockdep: Hash held lock's read-write type into chain key Yuyang Du
2019-05-13  9:11 ` [PATCH 10/17] locking/lockdep: Support read-write lock's deadlock detection Yuyang Du
2019-05-13  9:11 ` [PATCH 11/17] locking/lockdep: Adjust lockdep selftest cases Yuyang Du
2019-05-13  9:11 ` [PATCH 12/17] locking/lockdep: Remove useless lock type assignment Yuyang Du
2019-05-13  9:11 ` [PATCH 13/17] locking/lockdep: Add nest lock type Yuyang Du
2019-05-13  9:12 ` [PATCH 14/17] locking/lockdep: Support recursive read locks Yuyang Du
2019-05-13  9:12 ` [PATCH 15/17] locking/lockdep: Adjust selftest case for recursive read lock Yuyang Du
2019-05-13  9:12 ` [PATCH 16/17] locking/lockdep: Add more lockdep selftest cases Yuyang Du
2019-05-13  9:12 ` [PATCH 17/17] locking/lockdep: Remove irq-safe to irq-unsafe read check Yuyang Du
2019-05-13  9:17 ` [PATCH 00/17] Support for read-write lock deadlock detection Yuyang Du

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