diff mbox

[v2] IB/ipoib: replace local_irq_disable() with proper locking

Message ID 20180516194732.p4vk2lomdm6yisbq@linutronix.de (mailing list archive)
State Accepted
Delegated to: Jason Gunthorpe
Headers show

Commit Message

Sebastian Andrzej Siewior May 16, 2018, 7:47 p.m. UTC
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>
---
On 2018-05-16 11:05:09 [-0600], Jason Gunthorpe wrote:
> Send a v2 with a tighter commit message please

here it is.

> Jason

v1…v2: tighter commit message

 drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

Comments

Jason Gunthorpe May 17, 2018, 3:42 a.m. UTC | #1
On Wed, May 16, 2018 at 09:47:32PM +0200, Sebastian Andrzej Siewior wrote:
> 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>
> On 2018-05-16 11:05:09 [-0600], Jason Gunthorpe wrote:
> > Send a v2 with a tighter commit message please
> 
> here it is.
> 
> > Jason
> 
>  drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)

Applied to for-next, thanks

Jason
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diff mbox

Patch

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 9b3f47ae2016..6709328d90f8 100644
--- 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);
 	}
 }