| Message ID | 20200118042433.4968-1-frextrite@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | feec214afb53f17554c9c0c85f72de709b7ba3e4 |
| Headers | show |
| Series | [v2] drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists | expand |
On 1/17/20 8:24 PM, Amol Grover wrote: > 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. > Thanks. Acked-by: Santosh Shilimkar <ssantosh@kernel.org> > 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; \ >
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; \
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(-)