IB/ipoib: replace local_irq_disable() with proper locking

In ipoib_mcast_restart_task() the netif_addr_lock() is invoked prior
local_irq_save(). netif_addr_lock() should not be invoked in interrupt disabled
section, only in BH disabled sections.
The priv->lock is always acquired with disabled interrupts. The only place
where netif_addr_lock() and priv->lock nest ist ipoib_mcast_restart_task().

Drop the local_irq_save() and acquire priv->lock with spin_lock_irq() inside
the netif_addr locked section. It's safe to do so because the caller is either
a worker function or __ipoib_ib_dev_flush() which are both calling with
interrupts enabled (and since BH is enabled here, too so
netif_addr_lock_bh() needs to be used).

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 9b3f47ae201603e8bc4e1527a0b3546a0de69878..6709328d90f8b43c6b94e1f816ed611a25c6ea19 100644 (file)
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -886,7 +886,6 @@ void ipoib_mcast_restart_task(struct work_struct *work)
        struct netdev_hw_addr *ha;
        struct ipoib_mcast *mcast, *tmcast;
        LIST_HEAD(remove_list);
-       unsigned long flags;
        struct ib_sa_mcmember_rec rec;
 
        if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags))
@@ -898,9 +897,8 @@ void ipoib_mcast_restart_task(struct work_struct *work)
 
        ipoib_dbg_mcast(priv, "restarting multicast task\n");
 
-       local_irq_save(flags);
-       netif_addr_lock(dev);
-       spin_lock(&priv->lock);
+       netif_addr_lock_bh(dev);
+       spin_lock_irq(&priv->lock);
 
        /*
         * Unfortunately, the networking core only gives us a list of all of
@@ -978,9 +976,8 @@ void ipoib_mcast_restart_task(struct work_struct *work)
                }
        }
 
-       spin_unlock(&priv->lock);
-       netif_addr_unlock(dev);
-       local_irq_restore(flags);
+       spin_unlock_irq(&priv->lock);
+       netif_addr_unlock_bh(dev);
 
        ipoib_mcast_remove_list(&remove_list);
 
@@ -988,9 +985,9 @@ void ipoib_mcast_restart_task(struct work_struct *work)
         * Double check that we are still up
         */
        if (test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) {
-               spin_lock_irqsave(&priv->lock, flags);
+               spin_lock_irq(&priv->lock);
                __ipoib_mcast_schedule_join_thread(priv, NULL, 0);
-               spin_unlock_irqrestore(&priv->lock, flags);
+               spin_unlock_irq(&priv->lock);
        }
 }