[PATCH 3.16 227/366] virtio_console: reset on out of memory

Ben Hutchings
2018-10-14T23:11:45Z

From: "Michael S. Tsirkin" <mst@redhat.com>

commit 5c60300d68da32ca77f7f978039dc72bfc78b06b upstream.

When out of memory and we can't add ctrl vq buffers,
probe fails. Unfortunately the error handling is
out of spec: it calls del_vqs without bothering
to reset the device first.

To fix, call the full cleanup function in this case.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/char/virtio_console.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -2073,6 +2073,7 @@ static int virtcons_probe(struct virtio_

spin_lock_init(&portdev->ports_lock);
INIT_LIST_HEAD(&portdev->ports);
+ INIT_LIST_HEAD(&portdev->list);

INIT_WORK(&portdev->config_work, &config_work_handler);
INIT_WORK(&portdev->control_work, &control_work_handler);
@@ -2088,8 +2089,15 @@ static int virtcons_probe(struct virtio_
if (!nr_added_bufs) {
dev_err(&vdev->dev,
"Error allocating buffers for control queue\n");
- err = -ENOMEM;
- goto free_vqs;
+ /*
+ * The host might want to notify mgmt sw about device
+ * add failure.
+ */
+ __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
+ VIRTIO_CONSOLE_DEVICE_READY, 0);
+ /* Device was functional: we need full cleanup. */
+ virtcons_remove(vdev);
+ return -ENOMEM;
}
} else {
/*
@@ -2120,11 +2128,6 @@ static int virtcons_probe(struct virtio_

return 0;

-free_vqs:
- /* The host might want to notify mgmt sw about device add failure */
- __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
- VIRTIO_CONSOLE_DEVICE_READY, 0);
- remove_vqs(portdev);
free_chrdev:
unregister_chrdev(portdev->chr_major, "virtio-portsdev");