From: Amol Grover <frextrite@gmail.com>
To: Santosh Shilimkar <ssantosh@kernel.org>, Olof Johansson <olof@lixom.net>
Cc: santosh.shilimkar@oracle.com, arm@kernel.org, soc@kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel-mentees@lists.linuxfoundation.org,
Joel Fernandes <joel@joelfernandes.org>,
Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Amol Grover <frextrite@gmail.com>
Subject: [PATCH v2] drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists
Date: Sat, 18 Jan 2020 09:54:34 +0530 [thread overview]
Message-ID: <20200118042433.4968-1-frextrite@gmail.com> (raw)
inst->handles is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of knav_dev_lock.
Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.
Add macro for the corresponding lockdep expression.
Signed-off-by: Amol Grover <frextrite@gmail.com>
---
v2:
- Remove rcu_read_lock_held() from lockdep expression since it is
implicitly checked for.
drivers/soc/ti/knav_qmss_queue.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c
index 1ccc9064e1eb..37f3db6c041c 100644
--- a/drivers/soc/ti/knav_qmss_queue.c
+++ b/drivers/soc/ti/knav_qmss_queue.c
@@ -25,6 +25,8 @@
static struct knav_device *kdev;
static DEFINE_MUTEX(knav_dev_lock);
+#define knav_dev_lock_held() \
+ lockdep_is_held(&knav_dev_lock)
/* Queue manager register indices in DTS */
#define KNAV_QUEUE_PEEK_REG_INDEX 0
@@ -52,8 +54,9 @@ static DEFINE_MUTEX(knav_dev_lock);
#define knav_queue_idx_to_inst(kdev, idx) \
(kdev->instances + (idx << kdev->inst_shift))
-#define for_each_handle_rcu(qh, inst) \
- list_for_each_entry_rcu(qh, &inst->handles, list)
+#define for_each_handle_rcu(qh, inst) \
+ list_for_each_entry_rcu(qh, &inst->handles, list, \
+ knav_dev_lock_held())
#define for_each_instance(idx, inst, kdev) \
for (idx = 0, inst = kdev->instances; \
--
2.24.1
next reply other threads:[~2020-01-18 4:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-18 4:24 Amol Grover [this message]
2020-01-18 18:06 ` [PATCH v2] drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists santosh.shilimkar
-- strict thread matches above, loose matches on Subject: below --
2020-01-17 13:30 Amol Grover
2020-01-17 18:24 ` santosh.shilimkar
2020-01-17 19:25 ` Olof Johansson
2020-01-18 4:07 ` Amol Grover
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