Some modifications of vtermno were not done under the spinlock.
Moved assignment from vtermno and increment of vtermno together,
putting both under the spinlock. Revert vtermno on failure.
Signed-off-by: Miche Baker-Harvey <miche@xxxxxxxxxx>
---
drivers/char/virtio_console.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 8e3c46d..9722e76 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -987,18 +987,21 @@ int init_port_console(struct port *port)
* pointers. The final argument is the output buffer size: we
* can do any size, so we put PAGE_SIZE here.
*/
- port->cons.vtermno = pdrvdata.next_vtermno;
+ spin_lock_irq(&pdrvdata_lock);
+ port->cons.vtermno = pdrvdata.next_vtermno++;
+ spin_unlock_irq(&pdrvdata_lock);
port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
+ spin_lock_irq(&pdrvdata_lock);
if (IS_ERR(port->cons.hvc)) {
ret = PTR_ERR(port->cons.hvc);
dev_err(port->dev,
"error %d allocating hvc for port\n", ret);
port->cons.hvc = NULL;
+ port->cons.vtermno = pdrvdata.next_vtermno--;
+ spin_unlock_irq(&pdrvdata_lock);
return ret;
}
- spin_lock_irq(&pdrvdata_lock);
- pdrvdata.next_vtermno++;
list_add_tail(&port->cons.list, &pdrvdata.consoles);
spin_unlock_irq(&pdrvdata_lock);
port->guest_connected = true;
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