Patch "ibmvnic: remove excessive irqsave" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ibmvnic: remove excessive irqsave

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ibmvnic-remove-excessive-irqsave.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 60f94fa5e92bfed6ab8b309e3ad29555994ec525
Author: Junlin Yang <yangjunlin@xxxxxxxxxx>
Date:   Fri Mar 5 16:48:39 2021 +0800

    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@xxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 2aee81496ffa..4a4cb62b7332 100644
--- 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);