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| author | Jason Wang <jasowang@redhat.com> | 2018-01-23 12:27:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 13:05:39 +0300 |
| commit | bd3ccdc6f922c6b7db4b7075d1b6596ddb986a98 (patch) | |
| tree | 9a4234c9f218b9ab2caa0c3cc5a1f555d7e9ea86 /drivers/vhost | |
| parent | 80c1c8322c331586a86e58d3f95026a1265ab396 (diff) | |
| download | linux-bd3ccdc6f922c6b7db4b7075d1b6596ddb986a98.tar.xz | |
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>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vhost.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 64613fbf5cf8..cd38f5add254 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) |