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authorJason Wang <jasowang@redhat.com>2018-01-23 17:27:25 +0800
committerAlistair Strachan <astrachan@google.com>2019-01-15 17:08:37 -0800
commitb2696b4a37bdb9f2716017859a88b95ca6e30088 (patch)
tree5e7265a5a985b06735e56151a81ea51ddd209e64
parentb53fc49147e25e6a6f672b319f3091c53f024f10 (diff)
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: syzbot+dbb7c1161485e61b0241@syzkaller.appspotmail.com Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg 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: Alistair Strachan <astrachan@google.com> Change-Id: I20829e721706c10ef1696de0d78dd99110e40a6b
-rw-r--r--drivers/vhost/vhost.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 80013975cfac..854eb40f019d 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -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)