ibmvnic: remove excessive irqsave

[ Upstream commit 69cdb7947adb816fc9325b4ec02a6dddd5070b82 ]

ibmvnic_remove locks multiple spinlocks while disabling interrupts:
spin_lock_irqsave(&adapter->state_lock, flags);
spin_lock_irqsave(&adapter->rwi_lock, flags);

As reported by coccinelle, the second _irqsave() overwrites the value
saved in 'flags' by the first _irqsave(),   therefore when the second
_irqrestore() comes,the value in 'flags' is not valid,the value saved
by the first _irqsave() has been lost.
This likely leads to IRQs remaining disabled. So remove the second
_irqsave():
spin_lock_irqsave(&adapter->state_lock, flags);
spin_lock(&adapter->rwi_lock);

Generated by: ./scripts/coccinelle/locks/flags.cocci
./drivers/net/ethernet/ibm/ibmvnic.c:5413:1-18:
ERROR: nested lock+irqsave that reuses flags from line 5404.

Fixes: 4a41c421f367 ("ibmvnic: serialize access to work queue on remove")
Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 2aee814..4a4cb62 100644 (file)
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -5388,9 +5388,9 @@ static int ibmvnic_remove(struct vio_dev *dev)
         * after setting state, so __ibmvnic_reset() which is called
         * from the flush_work() below, can make progress.
         */
-       spin_lock_irqsave(&adapter->rwi_lock, flags);
+       spin_lock(&adapter->rwi_lock);
        adapter->state = VNIC_REMOVING;
-       spin_unlock_irqrestore(&adapter->rwi_lock, flags);
+       spin_unlock(&adapter->rwi_lock);
 
        spin_unlock_irqrestore(&adapter->state_lock, flags);