lkml.org 
[lkml]   [2020]   [Jan]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists
Date
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
\
 
 \ /
  Last update: 2020-01-18 05:26    [W:0.032 / U:0.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site