Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio update from Rusty Russell:
 "More console fixes; these are the theoretical ones which didn't get
  CC:stable.  But for that reason, I did a merge with master partway
  through to avoid an unnecessary conflict.

  Also: a fun lguest bug turns out if you don't clear the TF flag when
  trapping Bad Things happen to the guest kernel as the stack
  overflows..."

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio_pci: pm: Use CONFIG_PM_SLEEP instead of CONFIG_PM
  lguest: fix GPF in guest when using gdb.
  lguest: fix guest kernel stack overflow when TF bit set.
  lguest: fix BUG_ON() in invalid guest page table.
  virtio: console: prevent use-after-free of port name in port unplug
  virtio: console: cleanup an error message
  virtio: console: fix locking around send_sigio_to_port()
  virtio: console: add locking in port unplug path
  virtio: console: add locks around buffer removal in port unplug path
  tools/lguest: offer VIRTIO_F_ANY_LAYOUT for net device.
  virtio tools: add .gitignore
  lguest: Point to the right directory for the lguest launcher

1 files changed, 16 insertions, 11 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index fc45567ad3ac..b79cf3e1b793 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1529,18 +1529,22 @@ static void remove_port_data(struct port *port)
 {
 	struct port_buffer *buf;
 
+	spin_lock_irq(&port->inbuf_lock);
 	/* Remove unused data this port might have received. */
 	discard_port_data(port);
 
-	reclaim_consumed_buffers(port);
-
 	/* Remove buffers we queued up for the Host to send us data in. */
 	while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
 		free_buf(buf, true);
+	spin_unlock_irq(&port->inbuf_lock);
+
+	spin_lock_irq(&port->outvq_lock);
+	reclaim_consumed_buffers(port);
 
 	/* Free pending buffers from the out-queue. */
 	while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
 		free_buf(buf, true);
+	spin_unlock_irq(&port->outvq_lock);
 }
 
 /*
@@ -1554,6 +1558,7 @@ static void unplug_port(struct port *port)
 	list_del(&port->list);
 	spin_unlock_irq(&port->portdev->ports_lock);
 
+	spin_lock_irq(&port->inbuf_lock);
 	if (port->guest_connected) {
 		/* Let the app know the port is going down. */
 		send_sigio_to_port(port);
@@ -1564,6 +1569,7 @@ static void unplug_port(struct port *port)
 
 		wake_up_interruptible(&port->waitqueue);
 	}
+	spin_unlock_irq(&port->inbuf_lock);
 
 	if (is_console_port(port)) {
 		spin_lock_irq(&pdrvdata_lock);
@@ -1585,9 +1591,8 @@ static void unplug_port(struct port *port)
 	device_destroy(pdrvdata.class, port->dev->devt);
 	cdev_del(port->cdev);
 
-	kfree(port->name);
-
 	debugfs_remove(port->debugfs_file);
+	kfree(port->name);
 
 	/*
 	 * Locks around here are not necessary - a port can't be
@@ -1681,7 +1686,9 @@ static void handle_control_message(struct ports_device *portdev,
 		 * If the guest is connected, it'll be interested in
 		 * knowing the host connection state changed.
 		 */
+		spin_lock_irq(&port->inbuf_lock);
 		send_sigio_to_port(port);
+		spin_unlock_irq(&port->inbuf_lock);
 		break;
 	case VIRTIO_CONSOLE_PORT_NAME:
 		/*
@@ -1801,13 +1808,13 @@ static void in_intr(struct virtqueue *vq)
 	if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
 		discard_port_data(port);
 
+	/* Send a SIGIO indicating new data in case the process asked for it */
+	send_sigio_to_port(port);
+
 	spin_unlock_irqrestore(&port->inbuf_lock, flags);
 
 	wake_up_interruptible(&port->waitqueue);
 
-	/* Send a SIGIO indicating new data in case the process asked for it */
-	send_sigio_to_port(port);
-
 	if (is_console_port(port) && hvc_poll(port->cons.hvc))
 		hvc_kick();
 }
@@ -2241,10 +2248,8 @@ static int __init init(void)
 	}
 
 	pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
-	if (!pdrvdata.debugfs_dir) {
-		pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
-			   PTR_ERR(pdrvdata.debugfs_dir));
-	}
+	if (!pdrvdata.debugfs_dir)
+		pr_warning("Error creating debugfs dir for virtio-ports\n");
 	INIT_LIST_HEAD(&pdrvdata.consoles);
 	INIT_LIST_HEAD(&pdrvdata.portdevs);