Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b2696b4a authored by Jason Wang's avatar Jason Wang Committed by Alistair Strachan
Browse files

UPSTREAM: vhost: use mutex_lock_nested() in vhost_dev_lock_vqs() 



commit e9cb4239134c860e5f92c75bf5321bd377bb505b upstream.

We used to call mutex_lock() in vhost_dev_lock_vqs() which tries to
hold mutexes of all virtqueues. This may confuse lockdep to report a
possible deadlock because of trying to hold locks belong to same
class. Switch to use mutex_lock_nested() to avoid false positive.

Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
Reported-by: default avatar <syzbot+dbb7c1161485e61b0241@syzkaller.appspotmail.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit bd3ccdc6f922c6b7db4b7075d1b6596ddb986a98)
Bug: 121166534
Test: Ran cuttlefish with android-4.4 + VSOCKETS, VMWARE_VMCI_VSOCKETS
Signed-off-by: default avatarAlistair Strachan <astrachan@google.com>

Change-Id: I20829e721706c10ef1696de0d78dd99110e40a6b
parent b53fc491

drivers/vhost/vhost.c

+1 −1
Original line number Diff line number Diff line
@@ -849,7 +849,7 @@ static void vhost_dev_lock_vqs(struct vhost_dev *d) 
{

	int i = 0;

	for (i = 0; i < d->nvqs; ++i)

		mutex_lock(&d->vqs[i]->mutex);

		mutex_lock_nested(&d->vqs[i]->mutex, i);

}



static void vhost_dev_unlock_vqs(struct vhost_dev *d)