diff options
Diffstat (limited to 'drivers/char/virtio_console.c')
| -rw-r--r-- | drivers/char/virtio_console.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index ece1546fbb20..5e3503a31312 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -175,6 +175,9 @@ struct port { /* Is the host device open */ bool host_connected; + + /* We should allow only one process to open a port */ + bool guest_connected; }; /* This is the very early arch-specified put chars function. */ @@ -528,6 +531,8 @@ static int port_fops_release(struct inode *inode, struct file *filp) /* Notify host of port being closed */ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); + port->guest_connected = false; + return 0; } @@ -546,6 +551,16 @@ static int port_fops_open(struct inode *inode, struct file *filp) if (is_console_port(port)) return -ENXIO; + /* Allow only one process to open a particular port at a time */ + spin_lock_irq(&port->inbuf_lock); + if (port->guest_connected) { + spin_unlock_irq(&port->inbuf_lock); + return -EMFILE; + } + + port->guest_connected = true; + spin_unlock_irq(&port->inbuf_lock); + /* Notify host of port being opened */ send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1); @@ -709,6 +724,7 @@ int init_port_console(struct port *port) pdrvdata.next_vtermno++; list_add_tail(&port->cons.list, &pdrvdata.consoles); spin_unlock_irq(&pdrvdata_lock); + port->guest_connected = true; /* Notify host of port being opened */ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); @@ -856,7 +872,7 @@ static int add_port(struct ports_device *portdev, u32 id) port->inbuf = NULL; port->cons.hvc = NULL; - port->host_connected = false; + port->host_connected = port->guest_connected = false; port->in_vq = portdev->in_vqs[port->id]; port->out_vq = portdev->out_vqs[port->id]; |