Commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback
operations") changes the holding of the per-connection mutex to be less
restrictive because at the time of that commit per-connection mutexes were
encapsulated by a per-driver level gb_dev.mutex.
Commit 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation")
on the other hand subtracts the driver level gb_dev.mutex but neglects to
move the mutex back to the place it was prior to commit d9fb3754ecf8
("greybus: loopback: Relax locking during loopback operations"), as a
result several members of the per connection struct gb_loopback are racy.
The solution is restoring the old location of mutex_unlock(&gb->mutex) as
it was in commit d9fb3754ecf8 ("greybus: loopback: Relax locking during
loopback operations").
Fixes: 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation")
Signed-off-by: Bryan O'Donoghue <pure.logic@xxxxxxxxxxxxxxxxx>
Cc: Johan Hovold <johan@xxxxxxxxxx>
Cc: Alex Elder <elder@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Mitch Tasman <tasman@xxxxxxxxxxxx>
Cc: greybus-dev@xxxxxxxxxxxxxxxx
Cc: devel@xxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/staging/greybus/loopback.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
index 3d92638..20d1b45 100644
--- a/drivers/staging/greybus/loopback.c
+++ b/drivers/staging/greybus/loopback.c
@@ -605,7 +605,6 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
op_async->ts = ktime_get();
op_async->pending = true;
atomic_inc(&gb->outstanding_operations);
- mutex_lock(&gb->mutex);
ret = gb_operation_request_send(operation,
gb_loopback_async_operation_callback,
0,
@@ -622,7 +621,6 @@ static int gb_loopback_async_operation(struct gb_loopback *gb, int type,
error:
gb_loopback_async_operation_put(op_async);
done:
- mutex_unlock(&gb->mutex);
return ret;
}
@@ -1013,7 +1011,6 @@ static int gb_loopback_fn(void *data)
type = gb->type;
if (ktime_to_ns(gb->ts) == 0)
gb->ts = ktime_get();
- mutex_unlock(&gb->mutex);
/* Else operations to perform */
if (gb->async) {
@@ -1041,6 +1038,7 @@ static int gb_loopback_fn(void *data)
gb_loopback_calculate_stats(gb, !!error);
}
gb->send_count++;
+ mutex_unlock(&gb->mutex);
if (us_wait) {
if (us_wait < 20000)
--
2.7.4
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